diff mbox series

[v8,2/8] hwtracing: hisi_ptt: Add trace function support for HiSilicon PCIe Tune and Trace device

Message ID 20220516125223.32012-3-yangyicong@hisilicon.com (mailing list archive)
State Superseded
Headers show
Series Add support for HiSilicon PCIe Tune and Trace device | expand

Commit Message

Yicong Yang May 16, 2022, 12:52 p.m. UTC
HiSilicon PCIe tune and trace device(PTT) is a PCIe Root Complex integrated
Endpoint(RCiEP) device, providing the capability to dynamically monitor and
tune the PCIe traffic and trace the TLP headers.

Add the driver for the device to enable the trace function. Register PMU
device of PTT trace, then users can use trace through perf command. The
driver makes use of perf AUX trace function and support the following
events to configure the trace:

- filter: select Root port or Endpoint to trace
- type: select the type of traced TLP headers
- direction: select the direction of traced TLP headers
- format: select the data format of the traced TLP headers

This patch initially add a basic driver of PTT trace.

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
---
 drivers/Makefile                 |   1 +
 drivers/hwtracing/Kconfig        |   2 +
 drivers/hwtracing/ptt/Kconfig    |  12 +
 drivers/hwtracing/ptt/Makefile   |   2 +
 drivers/hwtracing/ptt/hisi_ptt.c | 964 +++++++++++++++++++++++++++++++
 drivers/hwtracing/ptt/hisi_ptt.h | 178 ++++++
 6 files changed, 1159 insertions(+)
 create mode 100644 drivers/hwtracing/ptt/Kconfig
 create mode 100644 drivers/hwtracing/ptt/Makefile
 create mode 100644 drivers/hwtracing/ptt/hisi_ptt.c
 create mode 100644 drivers/hwtracing/ptt/hisi_ptt.h

Comments

Jonathan Cameron May 16, 2022, 2:03 p.m. UTC | #1
On Mon, 16 May 2022 20:52:17 +0800
Yicong Yang <yangyicong@hisilicon.com> wrote:

> HiSilicon PCIe tune and trace device(PTT) is a PCIe Root Complex integrated
> Endpoint(RCiEP) device, providing the capability to dynamically monitor and
> tune the PCIe traffic and trace the TLP headers.
> 
> Add the driver for the device to enable the trace function. Register PMU
> device of PTT trace, then users can use trace through perf command. The
> driver makes use of perf AUX trace function and support the following
> events to configure the trace:
> 
> - filter: select Root port or Endpoint to trace
> - type: select the type of traced TLP headers
> - direction: select the direction of traced TLP headers
> - format: select the data format of the traced TLP headers
> 
> This patch initially add a basic driver of PTT trace.
> 
> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>

Hi Yicong,

It's been a while since I looked at this driver, so I'll admit
I can't remember if any of the things I've raised below were
previously discussed. 

All minor stuff (biggest is question of failing cleanly in unlikely
case of failing the allocation in the filter addition vs carrying
on anyway), so feel free to add

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> diff --git a/drivers/hwtracing/ptt/Makefile b/drivers/hwtracing/ptt/Makefile
> new file mode 100644
> index 000000000000..908c09a98161
> --- /dev/null
> +++ b/drivers/hwtracing/ptt/Makefile
> @@ -0,0 +1,2 @@
> +# SPDX-License-Identifier: GPL-2.0
> +obj-$(CONFIG_HISI_PTT) += hisi_ptt.o
> diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c
> new file mode 100644
> index 000000000000..ef25ce98f664
> --- /dev/null
> +++ b/drivers/hwtracing/ptt/hisi_ptt.c


...


> +
> +static int hisi_ptt_init_filters(struct pci_dev *pdev, void *data)
> +{
> +	struct hisi_ptt_filter_desc *filter;
> +	struct hisi_ptt *hisi_ptt = data;
> +
> +	filter = kzalloc(sizeof(*filter), GFP_KERNEL);
> +	if (!filter) {
> +		pci_err(hisi_ptt->pdev, "failed to add filter %s\n", pci_name(pdev));

If this fails we carry on anyway (no error checking on the bus_walk).
I think we should error out in that case (would need to use a flag placed
somewhere in hisi_ptt to tell we had an error).

That would complicate the unwind though.
Easiest way to do that unwind is probably to register a separate
devm_add_action_or_reset() callback for each filter.

If you prefer to carry on even with this allocation error, then maybe add a comment
here somewhere to make it clear that will happen.

> +		return -ENOMEM;
> +	}
> +
> +	filter->devid = PCI_DEVID(pdev->bus->number, pdev->devfn);
> +
> +	if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT) {
> +		filter->is_port = true;
> +		list_add_tail(&filter->list, &hisi_ptt->port_filters);
> +
> +		/* Update the available port mask */
> +		hisi_ptt->port_mask |= hisi_ptt_get_filter_val(filter->devid, true);
> +	} else {
> +		list_add_tail(&filter->list, &hisi_ptt->req_filters);
> +	}
> +
> +	return 0;
> +}
> +
> +static void hisi_ptt_release_filters(void *data)
> +{
> +	struct hisi_ptt_filter_desc *filter, *tmp;
> +	struct hisi_ptt *hisi_ptt = data;
> +
> +	list_for_each_entry_safe(filter, tmp, &hisi_ptt->req_filters, list) {
> +		list_del(&filter->list);
> +		kfree(filter);

I think with separate release per entry above, this bit become simpler as
we walk all the elements in the devm_ callback list rather than two lists here.

> +	}
> +
> +	list_for_each_entry_safe(filter, tmp, &hisi_ptt->port_filters, list) {
> +		list_del(&filter->list);
> +		kfree(filter);
> +	}
> +}
> +

...

> +
> +static int hisi_ptt_init_ctrls(struct hisi_ptt *hisi_ptt)
> +{
> +	struct pci_dev *pdev = hisi_ptt->pdev;
> +	struct pci_bus *bus;
> +	int ret;
> +	u32 reg;
> +
> +	INIT_LIST_HEAD(&hisi_ptt->port_filters);
> +	INIT_LIST_HEAD(&hisi_ptt->req_filters);
> +
> +	ret = hisi_ptt_config_trace_buf(hisi_ptt);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * The device range register provides the information about the
> +	 * root ports which the RCiEP can control and trace. The RCiEP
> +	 * and the root ports it support are on the same PCIe core, with
> +	 * same domain number but maybe different bus number. The device
> +	 * range register will tell us which root ports we can support,
> +	 * Bit[31:16] indicates the upper BDF numbers of the root port,
> +	 * while Bit[15:0] indicates the lower.
> +	 */
> +	reg = readl(hisi_ptt->iobase + HISI_PTT_DEVICE_RANGE);
> +	hisi_ptt->upper_bdf = FIELD_GET(HISI_PTT_DEVICE_RANGE_UPPER, reg);
> +	hisi_ptt->lower_bdf = FIELD_GET(HISI_PTT_DEVICE_RANGE_LOWER, reg);
> +
> +	bus = pci_find_bus(pci_domain_nr(pdev->bus), PCI_BUS_NUM(hisi_ptt->upper_bdf));
> +	if (bus)
> +		pci_walk_bus(bus, hisi_ptt_init_filters, hisi_ptt);
> +
> +	ret = devm_add_action_or_reset(&pdev->dev, hisi_ptt_release_filters, hisi_ptt);
> +	if (ret)
> +		return ret;
> +
> +	hisi_ptt->trace_ctrl.on_cpu = -1;
> +	return 0;
> +}
> +
> +static ssize_t available_root_port_filters_show(struct device *dev,
> +						struct device_attribute *attr,
> +						char *buf)
> +{
> +	struct hisi_ptt *hisi_ptt = to_hisi_ptt(dev_get_drvdata(dev));
> +	struct hisi_ptt_filter_desc *filter;
> +	int pos = 0;
> +
> +	if (list_empty(&hisi_ptt->port_filters)) {
> +		pos = sysfs_emit(buf, "\n");
> +		goto out;
> +	}
> +
> +	list_for_each_entry(filter, &hisi_ptt->port_filters, list) {
> +		u16 devid = filter->devid;
> +		pos += sysfs_emit_at(buf, pos, "%04x:%02x:%02x.%d\t0x%05lx\n",
> +				     pci_domain_nr(hisi_ptt->pdev->bus),
> +				     PCI_BUS_NUM(devid),
> +				     PCI_SLOT(devid & 0xff),
> +				     PCI_FUNC(devid & 0xff),
> +				     hisi_ptt_get_filter_val(devid, true) |
> +				     HISI_PTT_PMU_FILTER_IS_PORT);
> +	}
> +
> +out:

As below. I'd directly return in the empty case and drop the label.

> +	return pos;
> +}
> +static DEVICE_ATTR_ADMIN_RO(available_root_port_filters);
> +
> +static ssize_t available_requester_filters_show(struct device *dev,
> +						struct device_attribute *attr,
> +						char *buf)
> +{
> +	struct hisi_ptt *hisi_ptt = to_hisi_ptt(dev_get_drvdata(dev));
> +	struct hisi_ptt_filter_desc *filter;
> +	int pos = 0;
> +
> +	if (list_empty(&hisi_ptt->req_filters)) {
> +		pos = sysfs_emit(buf, "\n");
> +		goto out;
> +	}
> +
> +	list_for_each_entry(filter, &hisi_ptt->req_filters, list) {
> +		u16 devid = filter->devid;
> +		pos += sysfs_emit_at(buf, pos, "%04x:%02x:%02x.%d\t0x%05x\n",
> +				     pci_domain_nr(hisi_ptt->pdev->bus),
> +				     PCI_BUS_NUM(devid),
> +				     PCI_SLOT(devid & 0xff),
> +				     PCI_FUNC(devid & 0xff),
> +				     hisi_ptt_get_filter_val(devid, false));
> +	}
> +
> +out:

Why bother with the label?  Given empty is a special case, you can
just do
	return sysfs_emit(buf, "\n");

above.

> +	return pos;
> +}
> +static DEVICE_ATTR_ADMIN_RO(available_requester_filters);


> +static int hisi_ptt_trace_valid_filter(struct hisi_ptt *hisi_ptt, u64 config)
> +{
> +	unsigned long val, port_mask = hisi_ptt->port_mask;
> +	struct hisi_ptt_filter_desc *filter;
> +	int ret = -EINVAL;
> +
> +	hisi_ptt->trace_ctrl.is_port = FIELD_GET(HISI_PTT_PMU_FILTER_IS_PORT, config);
> +	val = FIELD_GET(HISI_PTT_PMU_FILTER_VAL_MASK, config);
> +
> +	/*
> +	 * Port filters are defined as bit mask. For port filters, check
> +	 * the bits in the @val are within the range of hisi_ptt->port_mask
> +	 * and whether it's empty or not, otherwise user has specified
> +	 * some unsupported root ports.
> +	 *
> +	 * For Requester ID filters, walk the available filter list to see
> +	 * whether we have one matched.
> +	 */
> +	if (!hisi_ptt->trace_ctrl.is_port) {
> +		list_for_each_entry(filter, &hisi_ptt->req_filters, list) {
> +			if (val == hisi_ptt_get_filter_val(filter->devid, filter->is_port)) {
> +				ret = 0;
				return 0; ?

Unless someone has previously requested this particular form...


> +				break;
> +			}
> +		}
> +	} else if (bitmap_subset(&val, &port_mask, BITS_PER_LONG)) {
> +		ret = 0;

		return 0;

> +	}
> +
> +	if (ret)
> +		return ret;

If you get here, return -EINVAL;

> +
> +	return 0;
> +}
> +
> +static void hisi_ptt_pmu_init_configs(struct hisi_ptt *hisi_ptt, struct perf_event *event)

> +static int hisi_ptt_pmu_event_init(struct perf_event *event)
> +{
> +	struct hisi_ptt *hisi_ptt = to_hisi_ptt(event->pmu);
> +	int ret;
> +	u32 val;
> +
> +	if (event->cpu < 0) {
> +		dev_dbg(event->pmu->dev, "Per-task mode not supported\n");
> +		return -EOPNOTSUPP;
> +	}
> +
> +	if (event->attr.type != hisi_ptt->hisi_ptt_pmu.type)
> +		return -ENOENT;
> +
> +	ret = hisi_ptt_trace_valid_filter(hisi_ptt, event->attr.config);
> +	if (ret < 0)
> +		return ret;
> +
> +	val = FIELD_GET(HISI_PTT_PMU_DIRECTION_MASK, event->attr.config);
> +	ret = hisi_ptt_trace_valid_direction(val);
> +	if (ret < 0)
> +		return ret;
> +
> +	val = FIELD_GET(HISI_PTT_PMU_TYPE_MASK, event->attr.config);
> +	ret = hisi_ptt_trace_valid_type(val);
> +	if (ret < 0)
> +		return ret;
> +
> +	val = FIELD_GET(HISI_PTT_PMU_FORMAT_MASK, event->attr.config);
> +	ret = hisi_ptt_trace_valid_format(val);
You could do

	return hisi_ptt_trace_valid_format(val);

Up to you on this one.

> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +




> +/*
> + * The DMA of PTT trace can only use direct mapping, due to some
> + * hardware restriction. Check whether there is an IOMMU or the

"Check whether there is no IOMMU or the policy of the IOMMU domain
is passthrough, otherwise the trace cannot work."

(need the "no" for the IOMMU presence)

> + * policy of the IOMMU domain is passthrough, otherwise the trace
> + * cannot work.
> + *
> + * The PTT device is supposed to behind an ARM SMMUv3, which
> + * should have passthrough the device by a quirk.
> + */
> +static int hisi_ptt_check_iommu_mapping(struct pci_dev *pdev)
> +{
> +	struct iommu_domain *iommu_domain;
> +
> +	iommu_domain = iommu_get_domain_for_dev(&pdev->dev);
> +	if (!iommu_domain || iommu_domain->type == IOMMU_DOMAIN_IDENTITY)
> +		return 0;
> +
> +	return -EOPNOTSUPP;
> +}
> +

...

> +
> +static int hisi_ptt_cpu_teardown(unsigned int cpu, struct hlist_node *node)
> +{
> +	struct hisi_ptt *hisi_ptt;
> +	int target, src;
> +
> +	hisi_ptt = hlist_entry_safe(node, struct hisi_ptt, hotplug_node);
> +	src = hisi_ptt->trace_ctrl.on_cpu;
> +
> +	if (!hisi_ptt->trace_ctrl.started || src != cpu)
> +		return 0;
> +
> +	target = cpumask_any(cpumask_of_node(dev_to_node(&hisi_ptt->pdev->dev)));
> +	if (target < nr_cpumask_bits) {
> +		dev_err(hisi_ptt->hisi_ptt_pmu.dev, "no available cpu for perf context migration\n");

Very long line, and not obvious disadvantage in splitting it before the string.

> +		return 0;
> +	}
> +
> +	perf_pmu_migrate_context(&hisi_ptt->hisi_ptt_pmu, src, target);
> +	WARN_ON(irq_set_affinity(pci_irq_vector(hisi_ptt->pdev, HISI_PTT_TRACE_DMA_IRQ),
> +				 cpumask_of(cpu)));
> +	hisi_ptt->trace_ctrl.on_cpu = target;
> +
> +	return 0;
> +}
> +

> diff --git a/drivers/hwtracing/ptt/hisi_ptt.h b/drivers/hwtracing/ptt/hisi_ptt.h
> new file mode 100644
> index 000000000000..2344e4195648
> --- /dev/null
> +++ b/drivers/hwtracing/ptt/hisi_ptt.h


> +/**
> + * struct hisi_ptt_filter_desc - Descriptor of the PTT trace filter
> + * @list:    entry of this descriptor in the filter list
> + * @is_port: the PCI device of the filter is a Root Port or not
> + * @devid:   the PCI device's devid of the filter
> + */
> +struct hisi_ptt_filter_desc {
> +	struct list_head list;
> +	bool is_port;
> +	u16 devid;
> +};
> +
> +

Trivial if you are doing a v9: one blank line only.

> +/**
> + * struct hisi_ptt_pmu_buf - Descriptor of the AUX buffer of PTT trace
> + * @length:   size of the AUX buffer
> + * @nr_pages: number of pages of the AUX buffer
> + * @base:     start address of AUX buffer
> + * @pos:      position in the AUX buffer to commit traced data
> + */
> +struct hisi_ptt_pmu_buf {
> +	size_t length;
> +	int nr_pages;
> +	void *base;
> +	long pos;
> +};
> +
John Garry May 16, 2022, 4:23 p.m. UTC | #2
On 16/05/2022 13:52, Yicong Yang wrote:
> HiSilicon PCIe tune and trace device(PTT) is a PCIe Root Complex integrated
> Endpoint(RCiEP) device, providing the capability to dynamically monitor and
> tune the PCIe traffic and trace the TLP headers.
> 
> Add the driver for the device to enable the trace function. Register PMU
> device of PTT trace, then users can use trace through perf command. The
> driver makes use of perf AUX trace function and support the following
> events to configure the trace:
> 
> - filter: select Root port or Endpoint to trace
> - type: select the type of traced TLP headers
> - direction: select the direction of traced TLP headers
> - format: select the data format of the traced TLP headers
> 
> This patch initially add a basic driver of PTT trace.

Initially add basic trace support.

> 
> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>

Generally this looks ok, apart from nitpicking below, so, FWIW:
Reviewed-by: John Garry <john.garry@huawei.com>

> ---
>   drivers/Makefile                 |   1 +
>   drivers/hwtracing/Kconfig        |   2 +
>   drivers/hwtracing/ptt/Kconfig    |  12 +
>   drivers/hwtracing/ptt/Makefile   |   2 +
>   drivers/hwtracing/ptt/hisi_ptt.c | 964 +++++++++++++++++++++++++++++++
>   drivers/hwtracing/ptt/hisi_ptt.h | 178 ++++++
>   6 files changed, 1159 insertions(+)
>   create mode 100644 drivers/hwtracing/ptt/Kconfig
>   create mode 100644 drivers/hwtracing/ptt/Makefile
>   create mode 100644 drivers/hwtracing/ptt/hisi_ptt.c
>   create mode 100644 drivers/hwtracing/ptt/hisi_ptt.h
> 
> diff --git a/drivers/Makefile b/drivers/Makefile
> index 020780b6b4d2..662d50599467 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -175,6 +175,7 @@ obj-$(CONFIG_USB4)		+= thunderbolt/
>   obj-$(CONFIG_CORESIGHT)		+= hwtracing/coresight/
>   obj-y				+= hwtracing/intel_th/
>   obj-$(CONFIG_STM)		+= hwtracing/stm/
> +obj-$(CONFIG_HISI_PTT)		+= hwtracing/ptt/
>   obj-$(CONFIG_ANDROID)		+= android/
>   obj-$(CONFIG_NVMEM)		+= nvmem/
>   obj-$(CONFIG_FPGA)		+= fpga/
> diff --git a/drivers/hwtracing/Kconfig b/drivers/hwtracing/Kconfig
> index 13085835a636..911ee977103c 100644
> --- a/drivers/hwtracing/Kconfig
> +++ b/drivers/hwtracing/Kconfig
> @@ -5,4 +5,6 @@ source "drivers/hwtracing/stm/Kconfig"
>   
>   source "drivers/hwtracing/intel_th/Kconfig"
>   
> +source "drivers/hwtracing/ptt/Kconfig"
> +
>   endmenu
> diff --git a/drivers/hwtracing/ptt/Kconfig b/drivers/hwtracing/ptt/Kconfig
> new file mode 100644
> index 000000000000..6d46a09ffeb9
> --- /dev/null
> +++ b/drivers/hwtracing/ptt/Kconfig
> @@ -0,0 +1,12 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +config HISI_PTT
> +	tristate "HiSilicon PCIe Tune and Trace Device"
> +	depends on ARM64 || (COMPILE_TEST && 64BIT)
> +	depends on PCI && HAS_DMA && HAS_IOMEM && PERF_EVENTS
> +	help
> +	  HiSilicon PCIe Tune and Trace device exists as a PCIe RCiEP
> +	  device, and it provides support for PCIe traffic tuning and
> +	  tracing TLP headers to the memory.
> +
> +	  This driver can also be built as a module. If so, the module
> +	  will be called hisi_ptt.
> diff --git a/drivers/hwtracing/ptt/Makefile b/drivers/hwtracing/ptt/Makefile
> new file mode 100644
> index 000000000000..908c09a98161
> --- /dev/null
> +++ b/drivers/hwtracing/ptt/Makefile
> @@ -0,0 +1,2 @@
> +# SPDX-License-Identifier: GPL-2.0
> +obj-$(CONFIG_HISI_PTT) += hisi_ptt.o
> diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c
> new file mode 100644
> index 000000000000..ef25ce98f664
> --- /dev/null
> +++ b/drivers/hwtracing/ptt/hisi_ptt.c
> @@ -0,0 +1,964 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Driver for HiSilicon PCIe tune and trace device
> + *
> + * Copyright (c) 2022 HiSilicon Technologies Co., Ltd.
> + * Author: Yicong Yang <yangyicong@hisilicon.com>
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/bitops.h>
> +#include <linux/cpuhotplug.h>
> +#include <linux/delay.h>
> +#include <linux/dma-iommu.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/iommu.h>
> +#include <linux/iopoll.h>
> +#include <linux/module.h>
> +#include <linux/sysfs.h>
> +#include <linux/vmalloc.h>
> +
> +#include "hisi_ptt.h"
> +
> +/* Dynamic CPU hotplug state used by PTT */
> +static enum cpuhp_state hisi_ptt_pmu_online;
> +
> +static u16 hisi_ptt_get_filter_val(u16 devid, bool is_port)
> +{
> +	if (is_port)
> +		return BIT(HISI_PCIE_CORE_PORT_ID(devid & 0xff));
> +
> +	return devid;
> +}
> +
> +static bool hisi_ptt_wait_trace_hw_idle(struct hisi_ptt *hisi_ptt)
> +{
> +	u32 val;
> +
> +	return !readl_poll_timeout_atomic(hisi_ptt->iobase + HISI_PTT_TRACE_STS,
> +					  val, val & HISI_PTT_TRACE_IDLE,
> +					  HISI_PTT_WAIT_POLL_INTERVAL_US,
> +					  HISI_PTT_WAIT_TRACE_TIMEOUT_US);
> +}
> +
> +static void hisi_ptt_wait_dma_reset_done(struct hisi_ptt *hisi_ptt)
> +{
> +	u32 val;
> +
> +	readl_poll_timeout_atomic(hisi_ptt->iobase + HISI_PTT_TRACE_WR_STS,
> +				  val, !val, HISI_PTT_RESET_POLL_INTERVAL_US,
> +				  HISI_PTT_RESET_TIMEOUT_US);
> +}
> +
> +static void hisi_ptt_trace_end(struct hisi_ptt *hisi_ptt)
> +{
> +	writel(0, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
> +	hisi_ptt->trace_ctrl.started = false;
> +}
> +
> +static int hisi_ptt_trace_start(struct hisi_ptt *hisi_ptt)
> +{
> +	struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
> +	u32 val;
> +	int i;
> +
> +	/* Check device idle before start trace */
> +	if (!hisi_ptt_wait_trace_hw_idle(hisi_ptt)) {
> +		pci_err(hisi_ptt->pdev, "Failed to start trace, the device is still busy\n");
> +		return -EBUSY;
> +	}
> +
> +	ctrl->started = true;
> +
> +	/* Reset the DMA before start tracing */
> +	val = readl(hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
> +	val |= HISI_PTT_TRACE_CTRL_RST;
> +	writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
> +
> +	hisi_ptt_wait_dma_reset_done(hisi_ptt);
> +
> +	val = readl(hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
> +	val &= ~HISI_PTT_TRACE_CTRL_RST;
> +	writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
> +
> +	/* Reset the index of current buffer */
> +	hisi_ptt->trace_ctrl.buf_index = 0;
> +
> +	/* Zero the trace buffers */
> +	for (i = 0; i < HISI_PTT_TRACE_BUF_CNT; i++)
> +		memset(ctrl->trace_buf[i].addr, 0, HISI_PTT_TRACE_BUF_SIZE);
> +
> +	/* Clear the interrupt status */
> +	writel(HISI_PTT_TRACE_INT_STAT_MASK, hisi_ptt->iobase + HISI_PTT_TRACE_INT_STAT);
> +	writel(0, hisi_ptt->iobase + HISI_PTT_TRACE_INT_MASK);
> +
> +	/* Set the trace control register */
> +	val = FIELD_PREP(HISI_PTT_TRACE_CTRL_TYPE_SEL, ctrl->type);
> +	val |= FIELD_PREP(HISI_PTT_TRACE_CTRL_RXTX_SEL, ctrl->direction);
> +	val |= FIELD_PREP(HISI_PTT_TRACE_CTRL_DATA_FORMAT, ctrl->format);
> +	val |= FIELD_PREP(HISI_PTT_TRACE_CTRL_TARGET_SEL, hisi_ptt->trace_ctrl.filter);
> +	if (!hisi_ptt->trace_ctrl.is_port)
> +		val |= HISI_PTT_TRACE_CTRL_FILTER_MODE;
> +
> +	/* Start the Trace */
> +	val |= HISI_PTT_TRACE_CTRL_EN;
> +	writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
> +
> +	return 0;
> +}
> +
> +static int hisi_ptt_update_aux(struct hisi_ptt *hisi_ptt, int index, bool stop)
> +{
> +	struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
> +	struct perf_output_handle *handle = &ctrl->handle;
> +	struct perf_event *event = handle->event;
> +	struct hisi_ptt_pmu_buf *buf;
> +	size_t size;
> +	void *addr;
> +
> +	buf = perf_get_aux(handle);
> +	if (!buf || !handle->size)
> +		return -EINVAL;
> +
> +	addr = ctrl->trace_buf[ctrl->buf_index].addr;
> +
> +	/*
> +	 * If we're going to stop, read the size of already traced data from
> +	 * HISI_PTT_TRACE_WR_STS. Otherwise we're coming from the interrupt,
> +	 * the data size is always HISI_PTT_TRACE_BUF_SIZE.
> +	 */
> +	if (stop) {
> +		u32 reg;
> +
> +		reg = readl(hisi_ptt->iobase + HISI_PTT_TRACE_WR_STS);
> +		size = FIELD_GET(HISI_PTT_TRACE_WR_STS_WRITE, reg);
> +	} else {
> +		size = HISI_PTT_TRACE_BUF_SIZE;
> +	}
> +
> +	memcpy(buf->base + buf->pos, addr, size);
> +	buf->pos += size;
> +
> +	/*
> +	 * Just commit the traced data if we're going to stop. Otherwise if the
> +	 * resident AUX buffer cannot contain the data of next trace buffer,
> +	 * apply a new one.
> +	 */
> +	if (stop) {
> +		perf_aux_output_end(handle, buf->pos);
> +	} else if (buf->length - buf->pos < HISI_PTT_TRACE_BUF_SIZE) {
> +		perf_aux_output_end(handle, buf->pos);
> +
> +		buf = perf_aux_output_begin(handle, event);
> +		if (!buf)
> +			return -EINVAL;
> +
> +		buf->pos = handle->head % buf->length;
> +		if (buf->length - buf->pos < HISI_PTT_TRACE_BUF_SIZE) {
> +			perf_aux_output_end(handle, 0);
> +			return -EINVAL;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static irqreturn_t hisi_ptt_isr(int irq, void *context)
> +{
> +	struct hisi_ptt *hisi_ptt = context;
> +	u32 status, buf_idx;
> +
> +	status = readl(hisi_ptt->iobase + HISI_PTT_TRACE_INT_STAT);
> +	if (!(status & HISI_PTT_TRACE_INT_STAT_MASK))
> +		return IRQ_NONE;
> +
> +	buf_idx = ffs(status) - 1;
> +
> +	/* Clear the interrupt status of buffer @buf_idx */
> +	writel(status, hisi_ptt->iobase + HISI_PTT_TRACE_INT_STAT);
> +
> +	/*
> +	 * Update the AUX buffer and cache the current buffer index,
> +	 * as we need to know this and save the data when the trace
> +	 * is ended out of the interrupt handler. End the trace
> +	 * if the updating fails.
> +	 */
> +	if (hisi_ptt_update_aux(hisi_ptt, buf_idx, false))
> +		hisi_ptt_trace_end(hisi_ptt);
> +	else
> +		hisi_ptt->trace_ctrl.buf_index = (buf_idx + 1) % HISI_PTT_TRACE_BUF_CNT;
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static void hisi_ptt_irq_free_vectors(void *pdev)
> +{
> +	pci_free_irq_vectors(pdev);
> +}
> +
> +static int hisi_ptt_register_irq(struct hisi_ptt *hisi_ptt)
> +{
> +	struct pci_dev *pdev = hisi_ptt->pdev;
> +	int ret;
> +
> +	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
> +	if (ret < 0) {
> +		pci_err(pdev, "failed to allocate irq vector, ret = %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = devm_add_action_or_reset(&pdev->dev, hisi_ptt_irq_free_vectors, pdev);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = devm_request_threaded_irq(&pdev->dev,
> +					pci_irq_vector(pdev, HISI_PTT_TRACE_DMA_IRQ),
> +					NULL, hisi_ptt_isr, 0,
> +					DRV_NAME, hisi_ptt);
> +	if (ret) {
> +		pci_err(pdev, "failed to request irq %d, ret = %d\n",
> +			pci_irq_vector(pdev, HISI_PTT_TRACE_DMA_IRQ), ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int hisi_ptt_init_filters(struct pci_dev *pdev, void *data)
> +{
> +	struct hisi_ptt_filter_desc *filter;
> +	struct hisi_ptt *hisi_ptt = data;
> +
> +	filter = kzalloc(sizeof(*filter), GFP_KERNEL);
> +	if (!filter) {
> +		pci_err(hisi_ptt->pdev, "failed to add filter %s\n", pci_name(pdev));
> +		return -ENOMEM;
> +	}
> +
> +	filter->devid = PCI_DEVID(pdev->bus->number, pdev->devfn);
> +
> +	if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT) {
> +		filter->is_port = true;
> +		list_add_tail(&filter->list, &hisi_ptt->port_filters);
> +
> +		/* Update the available port mask */
> +		hisi_ptt->port_mask |= hisi_ptt_get_filter_val(filter->devid, true);
> +	} else {
> +		list_add_tail(&filter->list, &hisi_ptt->req_filters);
> +	}
> +
> +	return 0;
> +}
> +
> +static void hisi_ptt_release_filters(void *data)
> +{
> +	struct hisi_ptt_filter_desc *filter, *tmp;
> +	struct hisi_ptt *hisi_ptt = data;
> +
> +	list_for_each_entry_safe(filter, tmp, &hisi_ptt->req_filters, list) {
> +		list_del(&filter->list);
> +		kfree(filter);
> +	}
> +
> +	list_for_each_entry_safe(filter, tmp, &hisi_ptt->port_filters, list) {
> +		list_del(&filter->list);
> +		kfree(filter);
> +	}
> +}
> +
> +static int hisi_ptt_config_trace_buf(struct hisi_ptt *hisi_ptt)
> +{
> +	struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
> +	struct device *dev = &hisi_ptt->pdev->dev;
> +	int i;
> +
> +	ctrl->trace_buf = devm_kcalloc(dev, HISI_PTT_TRACE_BUF_CNT,
> +				       sizeof(*ctrl->trace_buf), GFP_KERNEL);
> +	if (!ctrl->trace_buf)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < HISI_PTT_TRACE_BUF_CNT; ++i) {
> +		ctrl->trace_buf[i].addr = dmam_alloc_coherent(dev, HISI_PTT_TRACE_BUF_SIZE,
> +							     &ctrl->trace_buf[i].dma,
> +							     GFP_KERNEL);
> +		if (!ctrl->trace_buf[i].addr)
> +			return -ENOMEM;
> +	}
> +
> +	/* Configure the trace DMA buffer */
> +	for (i = 0; i < HISI_PTT_TRACE_BUF_CNT; i++) {
> +		writel(lower_32_bits(ctrl->trace_buf[i].dma),
> +		       hisi_ptt->iobase + HISI_PTT_TRACE_ADDR_BASE_LO_0 +
> +		       i * HISI_PTT_TRACE_ADDR_STRIDE);
> +		writel(upper_32_bits(ctrl->trace_buf[i].dma),
> +		       hisi_ptt->iobase + HISI_PTT_TRACE_ADDR_BASE_HI_0 +
> +		       i * HISI_PTT_TRACE_ADDR_STRIDE);
> +	}
> +	writel(HISI_PTT_TRACE_BUF_SIZE, hisi_ptt->iobase + HISI_PTT_TRACE_ADDR_SIZE);
> +
> +	return 0;
> +}
> +
> +static int hisi_ptt_init_ctrls(struct hisi_ptt *hisi_ptt)
> +{
> +	struct pci_dev *pdev = hisi_ptt->pdev;
> +	struct pci_bus *bus;
> +	int ret;
> +	u32 reg;
> +
> +	INIT_LIST_HEAD(&hisi_ptt->port_filters);
> +	INIT_LIST_HEAD(&hisi_ptt->req_filters);
> +
> +	ret = hisi_ptt_config_trace_buf(hisi_ptt);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * The device range register provides the information about the
> +	 * root ports which the RCiEP can control and trace. The RCiEP
> +	 * and the root ports it support are on the same PCIe core, with

  ports which it supports are on the same ..

> +	 * same domain number but maybe different bus number. The device
> +	 * range register will tell us which root ports we can support,
> +	 * Bit[31:16] indicates the upper BDF numbers of the root port,
> +	 * while Bit[15:0] indicates the lower.
> +	 */
> +	reg = readl(hisi_ptt->iobase + HISI_PTT_DEVICE_RANGE);
> +	hisi_ptt->upper_bdf = FIELD_GET(HISI_PTT_DEVICE_RANGE_UPPER, reg);
> +	hisi_ptt->lower_bdf = FIELD_GET(HISI_PTT_DEVICE_RANGE_LOWER, reg);
> +
> +	bus = pci_find_bus(pci_domain_nr(pdev->bus), PCI_BUS_NUM(hisi_ptt->upper_bdf));
> +	if (bus)
> +		pci_walk_bus(bus, hisi_ptt_init_filters, hisi_ptt);
> +
> +	ret = devm_add_action_or_reset(&pdev->dev, hisi_ptt_release_filters, hisi_ptt);
> +	if (ret)
> +		return ret;
> +
> +	hisi_ptt->trace_ctrl.on_cpu = -1;
> +	return 0;
> +}
> +
> +static ssize_t available_root_port_filters_show(struct device *dev,
> +						struct device_attribute *attr,
> +						char *buf)
> +{
> +	struct hisi_ptt *hisi_ptt = to_hisi_ptt(dev_get_drvdata(dev));
> +	struct hisi_ptt_filter_desc *filter;
> +	int pos = 0;
> +
> +	if (list_empty(&hisi_ptt->port_filters)) {
> +		pos = sysfs_emit(buf, "\n");
> +		goto out;
> +	}
> +
> +	list_for_each_entry(filter, &hisi_ptt->port_filters, list) {
> +		u16 devid = filter->devid;
> +		pos += sysfs_emit_at(buf, pos, "%04x:%02x:%02x.%d\t0x%05lx\n",
> +				     pci_domain_nr(hisi_ptt->pdev->bus),
> +				     PCI_BUS_NUM(devid),
> +				     PCI_SLOT(devid & 0xff),
> +				     PCI_FUNC(devid & 0xff),
> +				     hisi_ptt_get_filter_val(devid, true) |
> +				     HISI_PTT_PMU_FILTER_IS_PORT);
> +	}
> +
> +out:
> +	return pos;
> +}
> +static DEVICE_ATTR_ADMIN_RO(available_root_port_filters);
> +
> +static ssize_t available_requester_filters_show(struct device *dev,
> +						struct device_attribute *attr,
> +						char *buf)
> +{
> +	struct hisi_ptt *hisi_ptt = to_hisi_ptt(dev_get_drvdata(dev));
> +	struct hisi_ptt_filter_desc *filter;
> +	int pos = 0;
> +
> +	if (list_empty(&hisi_ptt->req_filters)) {
> +		pos = sysfs_emit(buf, "\n");
> +		goto out;

nit: return immediately

> +	}
> +
> +	list_for_each_entry(filter, &hisi_ptt->req_filters, list) {
> +		u16 devid = filter->devid;
> +		pos += sysfs_emit_at(buf, pos, "%04x:%02x:%02x.%d\t0x%05x\n",
> +				     pci_domain_nr(hisi_ptt->pdev->bus),
> +				     PCI_BUS_NUM(devid),
> +				     PCI_SLOT(devid & 0xff),
> +				     PCI_FUNC(devid & 0xff),
> +				     hisi_ptt_get_filter_val(devid, false));
> +	}
> +
> +out:
> +	return pos;
> +}
> +static DEVICE_ATTR_ADMIN_RO(available_requester_filters);
> +
> +static ssize_t cpumask_show(struct device *dev, struct device_attribute *attr,
> +			    char *buf)
> +{
> +	struct hisi_ptt *hisi_ptt = to_hisi_ptt(dev_get_drvdata(dev));
> +	const cpumask_t *cpumask = cpumask_of_node(dev_to_node(&hisi_ptt->pdev->dev));
> +
> +	return cpumap_print_to_pagebuf(true, buf, cpumask);
> +}
> +static DEVICE_ATTR_RO(cpumask);
> +
> +static struct attribute *hisi_ptt_cpumask_attrs[] = {
> +	&dev_attr_cpumask.attr,
> +	NULL,

nit: no need to ',' on sentinel

> +};
> +
> +static const struct attribute_group hisi_ptt_cpumask_attr_group = {
> +	.attrs = hisi_ptt_cpumask_attrs,
> +};
> +
> +PMU_FORMAT_ATTR(filter,		"config:0-19");
> +PMU_FORMAT_ATTR(direction,	"config:20-23");
> +PMU_FORMAT_ATTR(type,		"config:24-31");
> +PMU_FORMAT_ATTR(format,		"config:32-35");
> +
> +static struct attribute *hisi_ptt_pmu_format_attrs[] = {
> +	&format_attr_filter.attr,
> +	&format_attr_direction.attr,
> +	&format_attr_type.attr,
> +	&format_attr_format.attr,
> +	NULL
> +};
> +
> +static struct attribute_group hisi_ptt_pmu_format_group = {
> +	.name = "format",
> +	.attrs = hisi_ptt_pmu_format_attrs,
> +};
> +
> +static struct attribute *hisi_ptt_pmu_filter_attrs[] = {
> +	&dev_attr_available_root_port_filters.attr,
> +	&dev_attr_available_requester_filters.attr,
> +	NULL
> +};
> +
> +static struct attribute_group hisi_ptt_pmu_filter_group = {
> +	.attrs = hisi_ptt_pmu_filter_attrs,
> +};
> +
> +static const struct attribute_group *hisi_ptt_pmu_groups[] = {
> +	&hisi_ptt_cpumask_attr_group,
> +	&hisi_ptt_pmu_format_group,
> +	&hisi_ptt_pmu_filter_group,
> +	NULL
> +};
> +
> +static int hisi_ptt_trace_valid_direction(u32 val)
> +{
> +	/*
> +	 * The supported value of the direction parameter. See hisi_ptt.rst
> +	 * documentation for more details.
> +	 */
> +	static const u32 hisi_ptt_trace_available_direction[] = {
> +		0,
> +		1,
> +		2,
> +		3,
> +	};
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(hisi_ptt_trace_available_direction); i++) {
> +		if (val == hisi_ptt_trace_available_direction[i])
> +			return 0;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int hisi_ptt_trace_valid_type(u32 val)
> +{
> +	/* Different types can be set simultaneously */
> +	static const u32 hisi_ptt_trace_available_type[] = {
> +		1,	/* posted_request */
> +		2,	/* non-posted_request */
> +		4,	/* completion */
> +	};
> +	int i;
> +
> +	if (!val)
> +		return -EINVAL;
> +
> +	/*
> +	 * Walk the available list and clear the valid bits of
> +	 * the config. If there is any resident bit after the
> +	 * walk then the config is invalid.
> +	 */
> +	for (i = 0; i < ARRAY_SIZE(hisi_ptt_trace_available_type); i++)
> +		val &= ~hisi_ptt_trace_available_type[i];
> +
> +	if (val)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static int hisi_ptt_trace_valid_format(u32 val)
> +{
> +	static const u32 hisi_ptt_trace_availble_format[] = {
> +		0,	/* 4DW */
> +		1,	/* 8DW */
> +	};
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(hisi_ptt_trace_availble_format); i++) {
> +		if (val == hisi_ptt_trace_availble_format[i])
> +			return 0;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int hisi_ptt_trace_valid_filter(struct hisi_ptt *hisi_ptt, u64 config)
> +{
> +	unsigned long val, port_mask = hisi_ptt->port_mask;
> +	struct hisi_ptt_filter_desc *filter;
> +	int ret = -EINVAL;
> +
> +	hisi_ptt->trace_ctrl.is_port = FIELD_GET(HISI_PTT_PMU_FILTER_IS_PORT, config);
> +	val = FIELD_GET(HISI_PTT_PMU_FILTER_VAL_MASK, config);
> +
> +	/*
> +	 * Port filters are defined as bit mask. For port filters, check
> +	 * the bits in the @val are within the range of hisi_ptt->port_mask
> +	 * and whether it's empty or not, otherwise user has specified
> +	 * some unsupported root ports.
> +	 *
> +	 * For Requester ID filters, walk the available filter list to see
> +	 * whether we have one matched.
> +	 */
> +	if (!hisi_ptt->trace_ctrl.is_port) {
> +		list_for_each_entry(filter, &hisi_ptt->req_filters, list) {
> +			if (val == hisi_ptt_get_filter_val(filter->devid, filter->is_port)) {
> +				ret = 0;
> +				break;
> +			}
> +		}
> +	} else if (bitmap_subset(&val, &port_mask, BITS_PER_LONG)) {
> +		ret = 0;
> +	}
> +
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static void hisi_ptt_pmu_init_configs(struct hisi_ptt *hisi_ptt, struct perf_event *event)
> +{
> +	struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
> +	u32 val;
> +
> +	val = FIELD_GET(HISI_PTT_PMU_FILTER_VAL_MASK, event->attr.config);
> +	hisi_ptt->trace_ctrl.filter = val;
> +
> +	val = FIELD_GET(HISI_PTT_PMU_DIRECTION_MASK, event->attr.config);
> +	ctrl->direction = val;
> +
> +	val = FIELD_GET(HISI_PTT_PMU_TYPE_MASK, event->attr.config);
> +	ctrl->type = val;
> +
> +	val = FIELD_GET(HISI_PTT_PMU_FORMAT_MASK, event->attr.config);
> +	ctrl->format = val;
> +}
> +
> +static int hisi_ptt_pmu_event_init(struct perf_event *event)
> +{
> +	struct hisi_ptt *hisi_ptt = to_hisi_ptt(event->pmu);
> +	int ret;
> +	u32 val;
> +
> +	if (event->cpu < 0) {
> +		dev_dbg(event->pmu->dev, "Per-task mode not supported\n");
> +		return -EOPNOTSUPP;
> +	}
> +
> +	if (event->attr.type != hisi_ptt->hisi_ptt_pmu.type)
> +		return -ENOENT;
> +
> +	ret = hisi_ptt_trace_valid_filter(hisi_ptt, event->attr.config);
> +	if (ret < 0)
> +		return ret;
> +
> +	val = FIELD_GET(HISI_PTT_PMU_DIRECTION_MASK, event->attr.config);
> +	ret = hisi_ptt_trace_valid_direction(val);
> +	if (ret < 0)
> +		return ret;
> +
> +	val = FIELD_GET(HISI_PTT_PMU_TYPE_MASK, event->attr.config);
> +	ret = hisi_ptt_trace_valid_type(val);
> +	if (ret < 0)
> +		return ret;
> +
> +	val = FIELD_GET(HISI_PTT_PMU_FORMAT_MASK, event->attr.config);
> +	ret = hisi_ptt_trace_valid_format(val);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static void *hisi_ptt_pmu_setup_aux(struct perf_event *event, void **pages,
> +				    int nr_pages, bool overwrite)
> +{
> +	struct hisi_ptt_pmu_buf *buf;
> +	struct page **pagelist;
> +	int i;
> +
> +	if (overwrite) {
> +		dev_warn(event->pmu->dev, "Overwrite mode is not supported\n");
> +		return NULL;
> +	}
> +
> +	/* If the pages size less than buffers, we cannot start trace */
> +	if (nr_pages < HISI_PTT_TRACE_TOTAL_BUF_SIZE / PAGE_SIZE)
> +		return NULL;
> +
> +	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
> +	if (!buf)
> +		return NULL;
> +
> +	pagelist = kcalloc(nr_pages, sizeof(*pagelist), GFP_KERNEL);
> +	if (!pagelist)
> +		goto err;
> +
> +	for (i = 0; i < nr_pages; i++)
> +		pagelist[i] = virt_to_page(pages[i]);
> +
> +	buf->base = vmap(pagelist, nr_pages, VM_MAP, PAGE_KERNEL);
> +	if (!buf->base) {
> +		kfree(pagelist);
> +		goto err;
> +	}
> +
> +	buf->nr_pages = nr_pages;
> +	buf->length = nr_pages * PAGE_SIZE;
> +	buf->pos = 0;
> +
> +	kfree(pagelist);
> +	return buf;
> +err:
> +	kfree(buf);
> +	return NULL;
> +}
> +
> +static void hisi_ptt_pmu_free_aux(void *aux)
> +{
> +	struct hisi_ptt_pmu_buf *buf = aux;
> +
> +	vunmap(buf->base);
> +	kfree(buf);
> +}
> +
> +static void hisi_ptt_pmu_start(struct perf_event *event, int flags)
> +{
> +	struct hisi_ptt *hisi_ptt = to_hisi_ptt(event->pmu);
> +	struct perf_output_handle *handle = &hisi_ptt->trace_ctrl.handle;
> +	struct hw_perf_event *hwc = &event->hw;
> +	struct device *dev = event->pmu->dev;
> +	struct hisi_ptt_pmu_buf *buf;
> +	int cpu = event->cpu;
> +	int ret;
> +
> +	hwc->state = 0;
> +
> +	/* Serialize the perf process if user specified several CPUs */
> +	spin_lock(&hisi_ptt->pmu_lock);
> +	if (hisi_ptt->trace_ctrl.started) {
> +		dev_dbg(dev, "trace has already started\n");
> +		goto stop;
> +	}
> +
> +	/*
> +	 * Handle the interrupt on the same cpu which starts the trace to avoid
> +	 * context mismatch. Otherwise we'll trigger the WARN from the perf
> +	 * core in event_function_local().
> +	 */
> +	WARN_ON(irq_set_affinity(pci_irq_vector(hisi_ptt->pdev, HISI_PTT_TRACE_DMA_IRQ),
> +				 cpumask_of(cpu)));
> +	hisi_ptt->trace_ctrl.on_cpu = cpu;
> +
> +	buf = perf_aux_output_begin(handle, event);
> +	if (!buf) {
> +		dev_dbg(dev, "aux output begin failed\n");
> +		goto stop;
> +	}
> +
> +	buf->pos = handle->head % buf->length;
> +
> +	hisi_ptt_pmu_init_configs(hisi_ptt, event);
> +
> +	ret = hisi_ptt_trace_start(hisi_ptt);
> +	if (ret) {
> +		dev_dbg(dev, "trace start failed, ret = %d\n", ret);
> +		perf_aux_output_end(handle, 0);
> +		goto stop;
> +	}
> +
> +	spin_unlock(&hisi_ptt->pmu_lock);
> +	return;
> +stop:
> +	event->hw.state |= PERF_HES_STOPPED;
> +	spin_unlock(&hisi_ptt->pmu_lock);
> +}
> +
> +static void hisi_ptt_pmu_stop(struct perf_event *event, int flags)
> +{
> +	struct hisi_ptt *hisi_ptt = to_hisi_ptt(event->pmu);
> +	struct hw_perf_event *hwc = &event->hw;
> +
> +	if (hwc->state & PERF_HES_STOPPED)
> +		return;
> +
> +	spin_lock(&hisi_ptt->pmu_lock);
> +	if (hisi_ptt->trace_ctrl.started) {
> +		hisi_ptt_trace_end(hisi_ptt);
> +		WARN(!hisi_ptt_wait_trace_hw_idle(hisi_ptt), "Device is still busy");
> +		hisi_ptt_update_aux(hisi_ptt, hisi_ptt->trace_ctrl.buf_index, true);
> +	}
> +	spin_unlock(&hisi_ptt->pmu_lock);
> +
> +	hwc->state |= PERF_HES_STOPPED;
> +	perf_event_update_userpage(event);
> +	hwc->state |= PERF_HES_UPTODATE;
> +}
> +
> +static int hisi_ptt_pmu_add(struct perf_event *event, int flags)
> +{
> +	struct hisi_ptt *hisi_ptt = to_hisi_ptt(event->pmu);
> +	struct hw_perf_event *hwc = &event->hw;
> +	int cpu = event->cpu;
> +
> +	/* Only allow the cpus on the device's node to add the event */
> +	if (!cpumask_test_cpu(cpu, cpumask_of_node(dev_to_node(&hisi_ptt->pdev->dev))))
> +		return 0;
> +
> +	hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
> +
> +	if (flags & PERF_EF_START) {
> +		hisi_ptt_pmu_start(event, PERF_EF_RELOAD);
> +		if (hwc->state & PERF_HES_STOPPED)
> +			return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static void hisi_ptt_pmu_del(struct perf_event *event, int flags)
> +{
> +	hisi_ptt_pmu_stop(event, PERF_EF_UPDATE);
> +}
> +
> +static void hisi_ptt_remove_cpuhp_instance(void *hotplug_node)
> +{
> +	cpuhp_state_remove_instance(hisi_ptt_pmu_online, hotplug_node);
> +}
> +
> +static void hisi_ptt_unregister_pmu(void *pmu)
> +{
> +	perf_pmu_unregister(pmu);
> +}
> +
> +static int hisi_ptt_register_pmu(struct hisi_ptt *hisi_ptt)
> +{
> +	u16 core_id, sicl_id;
> +	char *pmu_name;
> +	u32 reg;
> +	int ret;
> +
> +	ret = cpuhp_state_add_instance(hisi_ptt_pmu_online, &hisi_ptt->hotplug_node);
> +	if (ret)
> +		return ret;
> +
> +	ret = devm_add_action_or_reset(&hisi_ptt->pdev->dev,
> +				       hisi_ptt_remove_cpuhp_instance,
> +				       &hisi_ptt->hotplug_node);
> +	if (ret)
> +		return ret;
> +
> +	spin_lock_init(&hisi_ptt->pmu_lock);
> +
> +	hisi_ptt->hisi_ptt_pmu = (struct pmu) {
> +		.module		= THIS_MODULE,
> +		.capabilities	= PERF_PMU_CAP_EXCLUSIVE | PERF_PMU_CAP_ITRACE,
> +		.task_ctx_nr	= perf_sw_context,
> +		.attr_groups	= hisi_ptt_pmu_groups,
> +		.event_init	= hisi_ptt_pmu_event_init,
> +		.setup_aux	= hisi_ptt_pmu_setup_aux,
> +		.free_aux	= hisi_ptt_pmu_free_aux,
> +		.start		= hisi_ptt_pmu_start,
> +		.stop		= hisi_ptt_pmu_stop,
> +		.add		= hisi_ptt_pmu_add,
> +		.del		= hisi_ptt_pmu_del,
> +	};
> +
> +	reg = readl(hisi_ptt->iobase + HISI_PTT_LOCATION);
> +	core_id = FIELD_GET(HISI_PTT_CORE_ID, reg);
> +	sicl_id = FIELD_GET(HISI_PTT_SICL_ID, reg);
> +
> +	pmu_name = devm_kasprintf(&hisi_ptt->pdev->dev, GFP_KERNEL, "hisi_ptt%u_%u",
> +				  sicl_id, core_id);
> +	if (!pmu_name)
> +		return -ENOMEM;
> +
> +	ret = perf_pmu_register(&hisi_ptt->hisi_ptt_pmu, pmu_name, -1);
> +	if (ret)
> +		return ret;
> +
> +	return devm_add_action_or_reset(&hisi_ptt->pdev->dev,
> +					hisi_ptt_unregister_pmu,
> +					&hisi_ptt->hisi_ptt_pmu);
> +}
> +
> +/*
> + * The DMA of PTT trace can only use direct mapping, due to some

nit: drop ',' and use "mappings"

> + * hardware restriction. Check whether there is an IOMMU or the
> + * policy of the IOMMU domain is passthrough, otherwise the trace
> + * cannot work.
> + *
> + * The PTT device is supposed to behind an ARM SMMUv3, which
> + * should have passthrough the device by a quirk.
> + */
> +static int hisi_ptt_check_iommu_mapping(struct pci_dev *pdev)
> +{
> +	struct iommu_domain *iommu_domain;
> +
> +	iommu_domain = iommu_get_domain_for_dev(&pdev->dev);
> +	if (!iommu_domain || iommu_domain->type == IOMMU_DOMAIN_IDENTITY)
> +		return 0;
> +
> +	return -EOPNOTSUPP;
> +}
> +
> +static int hisi_ptt_probe(struct pci_dev *pdev,
> +			  const struct pci_device_id *id)
> +{
> +	struct hisi_ptt *hisi_ptt;
> +	int ret;
> +
> +	ret = hisi_ptt_check_iommu_mapping(pdev);
> +	if (ret) {
> +		pci_err(pdev, "requires direct DMA mappings\n");
> +		return ret;
> +	}
> +
> +	hisi_ptt = devm_kzalloc(&pdev->dev, sizeof(*hisi_ptt), GFP_KERNEL);
> +	if (!hisi_ptt)
> +		return -ENOMEM;
> +
> +	hisi_ptt->pdev = pdev;
> +	pci_set_drvdata(pdev, hisi_ptt);
> +
> +	ret = pcim_enable_device(pdev);
> +	if (ret) {
> +		pci_err(pdev, "failed to enable device, ret = %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = pcim_iomap_regions(pdev, BIT(2), DRV_NAME);
> +	if (ret) {
> +		pci_err(pdev, "failed to remap io memory, ret = %d\n", ret);
> +		return ret;
> +	}
> +
> +	hisi_ptt->iobase = pcim_iomap_table(pdev)[2];
> +
> +	ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64));
> +	if (ret) {
> +		pci_err(pdev, "failed to set 64 bit dma mask, ret = %d\n", ret);
> +		return ret;
> +	}
> +
> +	pci_set_master(pdev);
> +
> +	ret = hisi_ptt_register_irq(hisi_ptt);
> +	if (ret)
> +		return ret;
> +
> +	ret = hisi_ptt_init_ctrls(hisi_ptt);
> +	if (ret) {
> +		pci_err(pdev, "failed to init controls, ret = %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = hisi_ptt_register_pmu(hisi_ptt);
> +	if (ret) {
> +		pci_err(pdev, "failed to register PMU device, ret = %d", ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct pci_device_id hisi_ptt_id_tbl[] = {
> +	{ PCI_DEVICE(PCI_VENDOR_ID_HUAWEI, 0xa12e) },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(pci, hisi_ptt_id_tbl);
> +
> +static struct pci_driver hisi_ptt_driver = {
> +	.name = DRV_NAME,
> +	.id_table = hisi_ptt_id_tbl,
> +	.probe = hisi_ptt_probe,
> +};
> +
> +static int hisi_ptt_cpu_teardown(unsigned int cpu, struct hlist_node *node)
> +{
> +	struct hisi_ptt *hisi_ptt;
> +	int target, src;
> +
> +	hisi_ptt = hlist_entry_safe(node, struct hisi_ptt, hotplug_node);
> +	src = hisi_ptt->trace_ctrl.on_cpu;
> +
> +	if (!hisi_ptt->trace_ctrl.started || src != cpu)
> +		return 0;
> +
> +	target = cpumask_any(cpumask_of_node(dev_to_node(&hisi_ptt->pdev->dev)));
> +	if (target < nr_cpumask_bits) {

the comment for cpumask_any() hints to check against nr_cpu_ids - any 
specific reason to check against nr_cpumask_bits?

> +		dev_err(hisi_ptt->hisi_ptt_pmu.dev, "no available cpu for perf context migration\n");
> +		return 0;
> +	}
> +
> +	perf_pmu_migrate_context(&hisi_ptt->hisi_ptt_pmu, src, target);
> +	WARN_ON(irq_set_affinity(pci_irq_vector(hisi_ptt->pdev, HISI_PTT_TRACE_DMA_IRQ),
> +				 cpumask_of(cpu)));
> +	hisi_ptt->trace_ctrl.on_cpu = target;
> +
> +	return 0;
> +}
> +
> +static int __init hisi_ptt_init(void)
> +{
> +	int ret;
> +
> +	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, DRV_NAME, NULL,
> +				      hisi_ptt_cpu_teardown);
> +	if (ret < 0)
> +		return ret;
> +	hisi_ptt_pmu_online = ret;
> +
> +	ret = pci_register_driver(&hisi_ptt_driver);
> +	if (ret)
> +		cpuhp_remove_multi_state(hisi_ptt_pmu_online);
> +
> +	return ret;
> +}
> +module_init(hisi_ptt_init);
> +
> +static void __exit hisi_ptt_exit(void)
> +{
> +	pci_unregister_driver(&hisi_ptt_driver);
> +	cpuhp_remove_multi_state(hisi_ptt_pmu_online);
> +}
> +module_exit(hisi_ptt_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Yicong Yang <yangyicong@hisilicon.com>");
> +MODULE_DESCRIPTION("Driver for HiSilicon PCIe tune and trace device");
> diff --git a/drivers/hwtracing/ptt/hisi_ptt.h b/drivers/hwtracing/ptt/hisi_ptt.h
> new file mode 100644
> index 000000000000..2344e4195648
> --- /dev/null
> +++ b/drivers/hwtracing/ptt/hisi_ptt.h
> @@ -0,0 +1,178 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Driver for HiSilicon PCIe tune and trace device
> + *
> + * Copyright (c) 2022 HiSilicon Technologies Co., Ltd.
> + * Author: Yicong Yang <yangyicong@hisilicon.com>
> + */
> +
> +#ifndef _HISI_PTT_H
> +#define _HISI_PTT_H
> +
> +#include <linux/bits.h>
> +#include <linux/cpumask.h>
> +#include <linux/list.h>
> +#include <linux/pci.h>
> +#include <linux/perf_event.h>
> +#include <linux/spinlock.h>
> +#include <linux/types.h>
> +
> +#define DRV_NAME "hisi_ptt"
> +
> +/*
> + * The definition of the device registers and register fields.
> + */
> +#define HISI_PTT_TRACE_ADDR_SIZE	0x0800
> +#define HISI_PTT_TRACE_ADDR_BASE_LO_0	0x0810
> +#define HISI_PTT_TRACE_ADDR_BASE_HI_0	0x0814
> +#define HISI_PTT_TRACE_ADDR_STRIDE	0x8
> +#define HISI_PTT_TRACE_CTRL		0x0850
> +#define   HISI_PTT_TRACE_CTRL_EN	BIT(0)
> +#define   HISI_PTT_TRACE_CTRL_RST	BIT(1)
> +#define   HISI_PTT_TRACE_CTRL_RXTX_SEL	GENMASK(3, 2)
> +#define   HISI_PTT_TRACE_CTRL_TYPE_SEL	GENMASK(7, 4)
> +#define   HISI_PTT_TRACE_CTRL_DATA_FORMAT	BIT(14)
> +#define   HISI_PTT_TRACE_CTRL_FILTER_MODE	BIT(15)
> +#define   HISI_PTT_TRACE_CTRL_TARGET_SEL	GENMASK(31, 16)
> +#define HISI_PTT_TRACE_INT_STAT		0x0890
> +#define   HISI_PTT_TRACE_INT_STAT_MASK	GENMASK(3, 0)
> +#define HISI_PTT_TRACE_INT_MASK		0x0894
> +#define HISI_PTT_TRACE_WR_STS		0x08a0
> +#define   HISI_PTT_TRACE_WR_STS_WRITE	GENMASK(27, 0)
> +#define   HISI_PTT_TRACE_WR_STS_BUFFER	GENMASK(29, 28)
> +#define HISI_PTT_TRACE_STS		0x08b0
> +#define   HISI_PTT_TRACE_IDLE		BIT(0)
> +#define HISI_PTT_DEVICE_RANGE		0x0fe0
> +#define   HISI_PTT_DEVICE_RANGE_UPPER	GENMASK(31, 16)
> +#define   HISI_PTT_DEVICE_RANGE_LOWER	GENMASK(15, 0)
> +#define HISI_PTT_LOCATION		0x0fe8
> +#define   HISI_PTT_CORE_ID		GENMASK(15, 0)
> +#define   HISI_PTT_SICL_ID		GENMASK(31, 16)
> +
> +/* Parameters of PTT trace DMA part. */
> +#define HISI_PTT_TRACE_DMA_IRQ			0
> +#define HISI_PTT_TRACE_BUF_CNT			4
> +#define HISI_PTT_TRACE_BUF_SIZE			SZ_4M
> +#define HISI_PTT_TRACE_TOTAL_BUF_SIZE		(HISI_PTT_TRACE_BUF_SIZE * \
> +						 HISI_PTT_TRACE_BUF_CNT)
> +/* Wait time for hardware DMA to reset */
> +#define HISI_PTT_RESET_TIMEOUT_US	10UL
> +#define HISI_PTT_RESET_POLL_INTERVAL_US	1UL
> +/* Poll timeout and interval for waiting hardware work to finish */
> +#define HISI_PTT_WAIT_TRACE_TIMEOUT_US	100UL
> +#define HISI_PTT_WAIT_POLL_INTERVAL_US	10UL
> +
> +#define HISI_PCIE_CORE_PORT_ID(devfn)	(PCI_FUNC(devfn) << 1)
> +
> +/* Definition of the PMU configs */
> +#define HISI_PTT_PMU_FILTER_IS_PORT	BIT(19)
> +#define HISI_PTT_PMU_FILTER_VAL_MASK	GENMASK(15, 0)
> +#define HISI_PTT_PMU_DIRECTION_MASK	GENMASK(23, 20)
> +#define HISI_PTT_PMU_TYPE_MASK		GENMASK(31, 24)
> +#define HISI_PTT_PMU_FORMAT_MASK	GENMASK(35, 32)
> +
> +/**
> + * struct hisi_ptt_dma_buffer - Describe a single trace buffer of PTT trace.
> + *                              The detail of the data format is described
> + *                              in the documentation of PTT device.
> + * @dma:   DMA address of this buffer visible to the device
> + * @addr:  virtual address of this buffer visible to the cpu
> + */
> +struct hisi_ptt_dma_buffer {
> +	dma_addr_t dma;
> +	void *addr;
> +};
> +
> +/**
> + * struct hisi_ptt_trace_ctrl - Control and status of PTT trace
> + * @trace_buf: array of the trace buffers for holding the trace data.
> + *             the length will be HISI_PTT_TRACE_BUF_CNT.
> + * @handle:    perf output handle of current trace session
> + * @buf_index: the index of current using trace buffer
> + * @on_cpu:    current tracing cpu
> + * @started:   current trace status, true for started
> + * @is_port:   whether we're tracing root port or not
> + * @direction: direction of the TLP headers to trace
> + * @filter:    filter value for tracing the TLP headers
> + * @format:    format of the TLP headers to trace
> + * @type:      type of the TLP headers to trace
> + */
> +struct hisi_ptt_trace_ctrl {
> +	struct hisi_ptt_dma_buffer *trace_buf;
> +	struct perf_output_handle handle;
> +	u32 buf_index;
> +	int on_cpu;
> +	bool started;
> +	bool is_port;
> +	u32 direction:2;
> +	u32 filter:16;
> +	u32 format:1;
> +	u32 type:4;
> +};
> +
> +/**
> + * struct hisi_ptt_filter_desc - Descriptor of the PTT trace filter
> + * @list:    entry of this descriptor in the filter list
> + * @is_port: the PCI device of the filter is a Root Port or not
> + * @devid:   the PCI device's devid of the filter
> + */
> +struct hisi_ptt_filter_desc {
> +	struct list_head list;
> +	bool is_port;
> +	u16 devid;
> +};
> +
> +
> +/**
> + * struct hisi_ptt_pmu_buf - Descriptor of the AUX buffer of PTT trace
> + * @length:   size of the AUX buffer
> + * @nr_pages: number of pages of the AUX buffer
> + * @base:     start address of AUX buffer
> + * @pos:      position in the AUX buffer to commit traced data
> + */
> +struct hisi_ptt_pmu_buf {
> +	size_t length;
> +	int nr_pages;
> +	void *base;
> +	long pos;
> +};
> +
> +/**
> + * struct hisi_ptt - Per PTT device data
> + * @trace_ctrl:   the control information of PTT trace
> + * @hotplug_node: node for register cpu hotplug event
> + * @hisi_ptt_pmu: the pum device of trace
> + * @iobase:       base IO address of the device
> + * @pdev:         pci_dev of this PTT device
> + * @pmu_lock:     lock to serialize the perf process
> + * @upper_bdf:    the upper BDF range of the PCI devices managed by this PTT device
> + * @lower_bdf:    the lower BDF range of the PCI devices managed by this PTT device
> + * @port_filters: the filter list of root ports
> + * @req_filters:  the filter list of requester ID
> + * @port_mask:    port mask of the managed root ports
> + */
> +struct hisi_ptt {
> +	struct hisi_ptt_trace_ctrl trace_ctrl;
> +	struct hlist_node hotplug_node;
> +	struct pmu hisi_ptt_pmu;
> +	void __iomem *iobase;
> +	struct pci_dev *pdev;
> +	spinlock_t pmu_lock;
> +	u32 upper_bdf;
> +	u32 lower_bdf;
> +
> +	/*
> +	 * The trace TLP headers can either be filtered by certain
> +	 * root port, or by the requester ID. Organize the filters
> +	 * by @port_filters and @req_filters here. The mask of all
> +	 * the valid ports is also cached for doing sanity check
> +	 * of user input.
> +	 */
> +	struct list_head port_filters;
> +	struct list_head req_filters;
> +	u16 port_mask;
> +};
> +
> +#define to_hisi_ptt(pmu) container_of(pmu, struct hisi_ptt, hisi_ptt_pmu)
> +
> +#endif /* _HISI_PTT_H */
Yicong Yang May 17, 2022, 8:05 a.m. UTC | #3
On 2022/5/16 22:03, Jonathan Cameron wrote:
> On Mon, 16 May 2022 20:52:17 +0800
> Yicong Yang <yangyicong@hisilicon.com> wrote:
> 
>> HiSilicon PCIe tune and trace device(PTT) is a PCIe Root Complex integrated
>> Endpoint(RCiEP) device, providing the capability to dynamically monitor and
>> tune the PCIe traffic and trace the TLP headers.
>>
>> Add the driver for the device to enable the trace function. Register PMU
>> device of PTT trace, then users can use trace through perf command. The
>> driver makes use of perf AUX trace function and support the following
>> events to configure the trace:
>>
>> - filter: select Root port or Endpoint to trace
>> - type: select the type of traced TLP headers
>> - direction: select the direction of traced TLP headers
>> - format: select the data format of the traced TLP headers
>>
>> This patch initially add a basic driver of PTT trace.
>>
>> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
> 
> Hi Yicong,
> 
> It's been a while since I looked at this driver, so I'll admit
> I can't remember if any of the things I've raised below were
> previously discussed. 
> 
> All minor stuff (biggest is question of failing cleanly in unlikely
> case of failing the allocation in the filter addition vs carrying
> on anyway), so feel free to add
> 
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
>> diff --git a/drivers/hwtracing/ptt/Makefile b/drivers/hwtracing/ptt/Makefile
>> new file mode 100644
>> index 000000000000..908c09a98161
>> --- /dev/null
>> +++ b/drivers/hwtracing/ptt/Makefile
>> @@ -0,0 +1,2 @@
>> +# SPDX-License-Identifier: GPL-2.0
>> +obj-$(CONFIG_HISI_PTT) += hisi_ptt.o
>> diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c
>> new file mode 100644
>> index 000000000000..ef25ce98f664
>> --- /dev/null
>> +++ b/drivers/hwtracing/ptt/hisi_ptt.c
> 
> 
> ...
> 
> 
>> +
>> +static int hisi_ptt_init_filters(struct pci_dev *pdev, void *data)
>> +{
>> +	struct hisi_ptt_filter_desc *filter;
>> +	struct hisi_ptt *hisi_ptt = data;
>> +
>> +	filter = kzalloc(sizeof(*filter), GFP_KERNEL);
>> +	if (!filter) {
>> +		pci_err(hisi_ptt->pdev, "failed to add filter %s\n", pci_name(pdev));
> 
> If this fails we carry on anyway (no error checking on the bus_walk).
> I think we should error out in that case (would need to use a flag placed
> somewhere in hisi_ptt to tell we had an error).
> 
> That would complicate the unwind though.
> Easiest way to do that unwind is probably to register a separate
> devm_add_action_or_reset() callback for each filter.
> 
> If you prefer to carry on even with this allocation error, then maybe add a comment
> here somewhere to make it clear that will happen.
> 

I'd prefer to carry on with this memory allocation error because this may not be fatal
as: 1) the filter maybe partial initialized but the trace is available with resident
filters and 2) the driver log here provides enough information that which filter has
problem to add. 3) furthermore the tune function doesn't rely on this so we give a
chance for the tune to be available if the filter allocation failed.

The log message provide information about what happened here, will add a comment here
why we decide to carry on:

	/*
	 * We won't fail the probe if filter allocation failed here. The filters
	 * should be partial initialized and users would know which filter fails
	 * through the log. Other functions of PTT device are still available.
	 */
	filter = kzalloc(sizeof(*filter), GFP_KERNEL);
	if (!filter) {
		pci_err(hisi_ptt->pdev, "failed to add filter %s\n", pci_name(pdev));
		return -ENOMEM;
	}

It's better to manually manage the filters as we're going to add support of dynamically
updating the filters, which means the filter can be added/removed after probe. With
devres it'll be complex to keep the order (the new added one will be released before
the PMU unregistration, which is not expected).

Will address the rest comments.

Thanks,
Yicong

>> +		return -ENOMEM;
>> +	}
>> +
>> +	filter->devid = PCI_DEVID(pdev->bus->number, pdev->devfn);
>> +
>> +	if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT) {
>> +		filter->is_port = true;
>> +		list_add_tail(&filter->list, &hisi_ptt->port_filters);
>> +
>> +		/* Update the available port mask */
>> +		hisi_ptt->port_mask |= hisi_ptt_get_filter_val(filter->devid, true);
>> +	} else {
>> +		list_add_tail(&filter->list, &hisi_ptt->req_filters);
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static void hisi_ptt_release_filters(void *data)
>> +{
>> +	struct hisi_ptt_filter_desc *filter, *tmp;
>> +	struct hisi_ptt *hisi_ptt = data;
>> +
>> +	list_for_each_entry_safe(filter, tmp, &hisi_ptt->req_filters, list) {
>> +		list_del(&filter->list);
>> +		kfree(filter);
> 
> I think with separate release per entry above, this bit become simpler as
> we walk all the elements in the devm_ callback list rather than two lists here.
> 
>> +	}
>> +
>> +	list_for_each_entry_safe(filter, tmp, &hisi_ptt->port_filters, list) {
>> +		list_del(&filter->list);
>> +		kfree(filter);
>> +	}
>> +}
>> +
> 
> ...
> 
>> +
>> +static int hisi_ptt_init_ctrls(struct hisi_ptt *hisi_ptt)
>> +{
>> +	struct pci_dev *pdev = hisi_ptt->pdev;
>> +	struct pci_bus *bus;
>> +	int ret;
>> +	u32 reg;
>> +
>> +	INIT_LIST_HEAD(&hisi_ptt->port_filters);
>> +	INIT_LIST_HEAD(&hisi_ptt->req_filters);
>> +
>> +	ret = hisi_ptt_config_trace_buf(hisi_ptt);
>> +	if (ret)
>> +		return ret;
>> +
>> +	/*
>> +	 * The device range register provides the information about the
>> +	 * root ports which the RCiEP can control and trace. The RCiEP
>> +	 * and the root ports it support are on the same PCIe core, with
>> +	 * same domain number but maybe different bus number. The device
>> +	 * range register will tell us which root ports we can support,
>> +	 * Bit[31:16] indicates the upper BDF numbers of the root port,
>> +	 * while Bit[15:0] indicates the lower.
>> +	 */
>> +	reg = readl(hisi_ptt->iobase + HISI_PTT_DEVICE_RANGE);
>> +	hisi_ptt->upper_bdf = FIELD_GET(HISI_PTT_DEVICE_RANGE_UPPER, reg);
>> +	hisi_ptt->lower_bdf = FIELD_GET(HISI_PTT_DEVICE_RANGE_LOWER, reg);
>> +
>> +	bus = pci_find_bus(pci_domain_nr(pdev->bus), PCI_BUS_NUM(hisi_ptt->upper_bdf));
>> +	if (bus)
>> +		pci_walk_bus(bus, hisi_ptt_init_filters, hisi_ptt);
>> +
>> +	ret = devm_add_action_or_reset(&pdev->dev, hisi_ptt_release_filters, hisi_ptt);
>> +	if (ret)
>> +		return ret;
>> +
>> +	hisi_ptt->trace_ctrl.on_cpu = -1;
>> +	return 0;
>> +}
>> +
>> +static ssize_t available_root_port_filters_show(struct device *dev,
>> +						struct device_attribute *attr,
>> +						char *buf)
>> +{
>> +	struct hisi_ptt *hisi_ptt = to_hisi_ptt(dev_get_drvdata(dev));
>> +	struct hisi_ptt_filter_desc *filter;
>> +	int pos = 0;
>> +
>> +	if (list_empty(&hisi_ptt->port_filters)) {
>> +		pos = sysfs_emit(buf, "\n");
>> +		goto out;
>> +	}
>> +
>> +	list_for_each_entry(filter, &hisi_ptt->port_filters, list) {
>> +		u16 devid = filter->devid;
>> +		pos += sysfs_emit_at(buf, pos, "%04x:%02x:%02x.%d\t0x%05lx\n",
>> +				     pci_domain_nr(hisi_ptt->pdev->bus),
>> +				     PCI_BUS_NUM(devid),
>> +				     PCI_SLOT(devid & 0xff),
>> +				     PCI_FUNC(devid & 0xff),
>> +				     hisi_ptt_get_filter_val(devid, true) |
>> +				     HISI_PTT_PMU_FILTER_IS_PORT);
>> +	}
>> +
>> +out:
> 
> As below. I'd directly return in the empty case and drop the label.
> 
>> +	return pos;
>> +}
>> +static DEVICE_ATTR_ADMIN_RO(available_root_port_filters);
>> +
>> +static ssize_t available_requester_filters_show(struct device *dev,
>> +						struct device_attribute *attr,
>> +						char *buf)
>> +{
>> +	struct hisi_ptt *hisi_ptt = to_hisi_ptt(dev_get_drvdata(dev));
>> +	struct hisi_ptt_filter_desc *filter;
>> +	int pos = 0;
>> +
>> +	if (list_empty(&hisi_ptt->req_filters)) {
>> +		pos = sysfs_emit(buf, "\n");
>> +		goto out;
>> +	}
>> +
>> +	list_for_each_entry(filter, &hisi_ptt->req_filters, list) {
>> +		u16 devid = filter->devid;
>> +		pos += sysfs_emit_at(buf, pos, "%04x:%02x:%02x.%d\t0x%05x\n",
>> +				     pci_domain_nr(hisi_ptt->pdev->bus),
>> +				     PCI_BUS_NUM(devid),
>> +				     PCI_SLOT(devid & 0xff),
>> +				     PCI_FUNC(devid & 0xff),
>> +				     hisi_ptt_get_filter_val(devid, false));
>> +	}
>> +
>> +out:
> 
> Why bother with the label?  Given empty is a special case, you can
> just do
> 	return sysfs_emit(buf, "\n");
> 
> above.
> 
>> +	return pos;
>> +}
>> +static DEVICE_ATTR_ADMIN_RO(available_requester_filters);
> 
> 
>> +static int hisi_ptt_trace_valid_filter(struct hisi_ptt *hisi_ptt, u64 config)
>> +{
>> +	unsigned long val, port_mask = hisi_ptt->port_mask;
>> +	struct hisi_ptt_filter_desc *filter;
>> +	int ret = -EINVAL;
>> +
>> +	hisi_ptt->trace_ctrl.is_port = FIELD_GET(HISI_PTT_PMU_FILTER_IS_PORT, config);
>> +	val = FIELD_GET(HISI_PTT_PMU_FILTER_VAL_MASK, config);
>> +
>> +	/*
>> +	 * Port filters are defined as bit mask. For port filters, check
>> +	 * the bits in the @val are within the range of hisi_ptt->port_mask
>> +	 * and whether it's empty or not, otherwise user has specified
>> +	 * some unsupported root ports.
>> +	 *
>> +	 * For Requester ID filters, walk the available filter list to see
>> +	 * whether we have one matched.
>> +	 */
>> +	if (!hisi_ptt->trace_ctrl.is_port) {
>> +		list_for_each_entry(filter, &hisi_ptt->req_filters, list) {
>> +			if (val == hisi_ptt_get_filter_val(filter->devid, filter->is_port)) {
>> +				ret = 0;
> 				return 0; ?
> 
> Unless someone has previously requested this particular form...
> 
> 
>> +				break;
>> +			}
>> +		}
>> +	} else if (bitmap_subset(&val, &port_mask, BITS_PER_LONG)) {
>> +		ret = 0;
> 
> 		return 0;
> 
>> +	}
>> +
>> +	if (ret)
>> +		return ret;
> 
> If you get here, return -EINVAL;
> 
>> +
>> +	return 0;
>> +}
>> +
>> +static void hisi_ptt_pmu_init_configs(struct hisi_ptt *hisi_ptt, struct perf_event *event)
> 
>> +static int hisi_ptt_pmu_event_init(struct perf_event *event)
>> +{
>> +	struct hisi_ptt *hisi_ptt = to_hisi_ptt(event->pmu);
>> +	int ret;
>> +	u32 val;
>> +
>> +	if (event->cpu < 0) {
>> +		dev_dbg(event->pmu->dev, "Per-task mode not supported\n");
>> +		return -EOPNOTSUPP;
>> +	}
>> +
>> +	if (event->attr.type != hisi_ptt->hisi_ptt_pmu.type)
>> +		return -ENOENT;
>> +
>> +	ret = hisi_ptt_trace_valid_filter(hisi_ptt, event->attr.config);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	val = FIELD_GET(HISI_PTT_PMU_DIRECTION_MASK, event->attr.config);
>> +	ret = hisi_ptt_trace_valid_direction(val);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	val = FIELD_GET(HISI_PTT_PMU_TYPE_MASK, event->attr.config);
>> +	ret = hisi_ptt_trace_valid_type(val);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	val = FIELD_GET(HISI_PTT_PMU_FORMAT_MASK, event->attr.config);
>> +	ret = hisi_ptt_trace_valid_format(val);
> You could do
> 
> 	return hisi_ptt_trace_valid_format(val);
> 
> Up to you on this one.
> 
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	return 0;
>> +}
>> +
> 
> 
> 
> 
>> +/*
>> + * The DMA of PTT trace can only use direct mapping, due to some
>> + * hardware restriction. Check whether there is an IOMMU or the
> 
> "Check whether there is no IOMMU or the policy of the IOMMU domain
> is passthrough, otherwise the trace cannot work."
> 
> (need the "no" for the IOMMU presence)
> 
>> + * policy of the IOMMU domain is passthrough, otherwise the trace
>> + * cannot work.
>> + *
>> + * The PTT device is supposed to behind an ARM SMMUv3, which
>> + * should have passthrough the device by a quirk.
>> + */
>> +static int hisi_ptt_check_iommu_mapping(struct pci_dev *pdev)
>> +{
>> +	struct iommu_domain *iommu_domain;
>> +
>> +	iommu_domain = iommu_get_domain_for_dev(&pdev->dev);
>> +	if (!iommu_domain || iommu_domain->type == IOMMU_DOMAIN_IDENTITY)
>> +		return 0;
>> +
>> +	return -EOPNOTSUPP;
>> +}
>> +
> 
> ...
> 
>> +
>> +static int hisi_ptt_cpu_teardown(unsigned int cpu, struct hlist_node *node)
>> +{
>> +	struct hisi_ptt *hisi_ptt;
>> +	int target, src;
>> +
>> +	hisi_ptt = hlist_entry_safe(node, struct hisi_ptt, hotplug_node);
>> +	src = hisi_ptt->trace_ctrl.on_cpu;
>> +
>> +	if (!hisi_ptt->trace_ctrl.started || src != cpu)
>> +		return 0;
>> +
>> +	target = cpumask_any(cpumask_of_node(dev_to_node(&hisi_ptt->pdev->dev)));
>> +	if (target < nr_cpumask_bits) {
>> +		dev_err(hisi_ptt->hisi_ptt_pmu.dev, "no available cpu for perf context migration\n");
> 
> Very long line, and not obvious disadvantage in splitting it before the string.
> 
>> +		return 0;
>> +	}
>> +
>> +	perf_pmu_migrate_context(&hisi_ptt->hisi_ptt_pmu, src, target);
>> +	WARN_ON(irq_set_affinity(pci_irq_vector(hisi_ptt->pdev, HISI_PTT_TRACE_DMA_IRQ),
>> +				 cpumask_of(cpu)));
>> +	hisi_ptt->trace_ctrl.on_cpu = target;
>> +
>> +	return 0;
>> +}
>> +
> 
>> diff --git a/drivers/hwtracing/ptt/hisi_ptt.h b/drivers/hwtracing/ptt/hisi_ptt.h
>> new file mode 100644
>> index 000000000000..2344e4195648
>> --- /dev/null
>> +++ b/drivers/hwtracing/ptt/hisi_ptt.h
> 
> 
>> +/**
>> + * struct hisi_ptt_filter_desc - Descriptor of the PTT trace filter
>> + * @list:    entry of this descriptor in the filter list
>> + * @is_port: the PCI device of the filter is a Root Port or not
>> + * @devid:   the PCI device's devid of the filter
>> + */
>> +struct hisi_ptt_filter_desc {
>> +	struct list_head list;
>> +	bool is_port;
>> +	u16 devid;
>> +};
>> +
>> +
> 
> Trivial if you are doing a v9: one blank line only.
> 
>> +/**
>> + * struct hisi_ptt_pmu_buf - Descriptor of the AUX buffer of PTT trace
>> + * @length:   size of the AUX buffer
>> + * @nr_pages: number of pages of the AUX buffer
>> + * @base:     start address of AUX buffer
>> + * @pos:      position in the AUX buffer to commit traced data
>> + */
>> +struct hisi_ptt_pmu_buf {
>> +	size_t length;
>> +	int nr_pages;
>> +	void *base;
>> +	long pos;
>> +};
>> +
> 
> .
>
Yicong Yang May 17, 2022, 8:09 a.m. UTC | #4
On 2022/5/17 0:23, John Garry wrote:
> On 16/05/2022 13:52, Yicong Yang wrote:
>> HiSilicon PCIe tune and trace device(PTT) is a PCIe Root Complex integrated
>> Endpoint(RCiEP) device, providing the capability to dynamically monitor and
>> tune the PCIe traffic and trace the TLP headers.
>>
>> Add the driver for the device to enable the trace function. Register PMU
>> device of PTT trace, then users can use trace through perf command. The
>> driver makes use of perf AUX trace function and support the following
>> events to configure the trace:
>>
>> - filter: select Root port or Endpoint to trace
>> - type: select the type of traced TLP headers
>> - direction: select the direction of traced TLP headers
>> - format: select the data format of the traced TLP headers
>>
>> This patch initially add a basic driver of PTT trace.
> 
> Initially add basic trace support.
> 
>>
>> Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
> 
> Generally this looks ok, apart from nitpicking below, so, FWIW:
> Reviewed-by: John Garry <john.garry@huawei.com>
> >> ---
>>   drivers/Makefile                 |   1 +
>>   drivers/hwtracing/Kconfig        |   2 +
>>   drivers/hwtracing/ptt/Kconfig    |  12 +
>>   drivers/hwtracing/ptt/Makefile   |   2 +
>>   drivers/hwtracing/ptt/hisi_ptt.c | 964 +++++++++++++++++++++++++++++++
>>   drivers/hwtracing/ptt/hisi_ptt.h | 178 ++++++
>>   6 files changed, 1159 insertions(+)
>>   create mode 100644 drivers/hwtracing/ptt/Kconfig
>>   create mode 100644 drivers/hwtracing/ptt/Makefile
>>   create mode 100644 drivers/hwtracing/ptt/hisi_ptt.c
>>   create mode 100644 drivers/hwtracing/ptt/hisi_ptt.h
>>

[...]

>> +static int hisi_ptt_cpu_teardown(unsigned int cpu, struct hlist_node *node)
>> +{
>> +    struct hisi_ptt *hisi_ptt;
>> +    int target, src;
>> +
>> +    hisi_ptt = hlist_entry_safe(node, struct hisi_ptt, hotplug_node);
>> +    src = hisi_ptt->trace_ctrl.on_cpu;
>> +
>> +    if (!hisi_ptt->trace_ctrl.started || src != cpu)
>> +        return 0;
>> +
>> +    target = cpumask_any(cpumask_of_node(dev_to_node(&hisi_ptt->pdev->dev)));
>> +    if (target < nr_cpumask_bits) {
> 
> the comment for cpumask_any() hints to check against nr_cpu_ids - any specific reason to check against nr_cpumask_bits?
> 

here should be:
	if (target >= nr_cpumask_bits) {

will fix this up.

>> +        dev_err(hisi_ptt->hisi_ptt_pmu.dev, "no available cpu for perf context migration\n");
>> +        return 0;
>> +    }
>> +
>> +    perf_pmu_migrate_context(&hisi_ptt->hisi_ptt_pmu, src, target);
>> +    WARN_ON(irq_set_affinity(pci_irq_vector(hisi_ptt->pdev, HISI_PTT_TRACE_DMA_IRQ),
>> +                 cpumask_of(cpu)));
>> +    hisi_ptt->trace_ctrl.on_cpu = target;
>> +
>> +    return 0;
>> +}
>> +
>> +static int __init hisi_ptt_init(void)
>> +{
>> +    int ret;
>> +
>> +    ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, DRV_NAME, NULL,
>> +                      hisi_ptt_cpu_teardown);
>> +    if (ret < 0)
>> +        return ret;
>> +    hisi_ptt_pmu_online = ret;
>> +
>> +    ret = pci_register_driver(&hisi_ptt_driver);
>> +    if (ret)
>> +        cpuhp_remove_multi_state(hisi_ptt_pmu_online);
>> +
>> +    return ret;
>> +}
>> +module_init(hisi_ptt_init);
>> +
>> +static void __exit hisi_ptt_exit(void)
>> +{
>> +    pci_unregister_driver(&hisi_ptt_driver);
>> +    cpuhp_remove_multi_state(hisi_ptt_pmu_online);
>> +}
>> +module_exit(hisi_ptt_exit);
>> +
>> +MODULE_LICENSE("GPL");
>> +MODULE_AUTHOR("Yicong Yang <yangyicong@hisilicon.com>");
>> +MODULE_DESCRIPTION("Driver for HiSilicon PCIe tune and trace device");
>> diff --git a/drivers/hwtracing/ptt/hisi_ptt.h b/drivers/hwtracing/ptt/hisi_ptt.h
>> new file mode 100644
>> index 000000000000..2344e4195648
>> --- /dev/null
>> +++ b/drivers/hwtracing/ptt/hisi_ptt.h
>> @@ -0,0 +1,178 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + * Driver for HiSilicon PCIe tune and trace device
>> + *
>> + * Copyright (c) 2022 HiSilicon Technologies Co., Ltd.
>> + * Author: Yicong Yang <yangyicong@hisilicon.com>
>> + */
>> +
>> +#ifndef _HISI_PTT_H
>> +#define _HISI_PTT_H
>> +
>> +#include <linux/bits.h>
>> +#include <linux/cpumask.h>
>> +#include <linux/list.h>
>> +#include <linux/pci.h>
>> +#include <linux/perf_event.h>
>> +#include <linux/spinlock.h>
>> +#include <linux/types.h>
>> +
>> +#define DRV_NAME "hisi_ptt"
>> +
>> +/*
>> + * The definition of the device registers and register fields.
>> + */
>> +#define HISI_PTT_TRACE_ADDR_SIZE    0x0800
>> +#define HISI_PTT_TRACE_ADDR_BASE_LO_0    0x0810
>> +#define HISI_PTT_TRACE_ADDR_BASE_HI_0    0x0814
>> +#define HISI_PTT_TRACE_ADDR_STRIDE    0x8
>> +#define HISI_PTT_TRACE_CTRL        0x0850
>> +#define   HISI_PTT_TRACE_CTRL_EN    BIT(0)
>> +#define   HISI_PTT_TRACE_CTRL_RST    BIT(1)
>> +#define   HISI_PTT_TRACE_CTRL_RXTX_SEL    GENMASK(3, 2)
>> +#define   HISI_PTT_TRACE_CTRL_TYPE_SEL    GENMASK(7, 4)
>> +#define   HISI_PTT_TRACE_CTRL_DATA_FORMAT    BIT(14)
>> +#define   HISI_PTT_TRACE_CTRL_FILTER_MODE    BIT(15)
>> +#define   HISI_PTT_TRACE_CTRL_TARGET_SEL    GENMASK(31, 16)
>> +#define HISI_PTT_TRACE_INT_STAT        0x0890
>> +#define   HISI_PTT_TRACE_INT_STAT_MASK    GENMASK(3, 0)
>> +#define HISI_PTT_TRACE_INT_MASK        0x0894
>> +#define HISI_PTT_TRACE_WR_STS        0x08a0
>> +#define   HISI_PTT_TRACE_WR_STS_WRITE    GENMASK(27, 0)
>> +#define   HISI_PTT_TRACE_WR_STS_BUFFER    GENMASK(29, 28)
>> +#define HISI_PTT_TRACE_STS        0x08b0
>> +#define   HISI_PTT_TRACE_IDLE        BIT(0)
>> +#define HISI_PTT_DEVICE_RANGE        0x0fe0
>> +#define   HISI_PTT_DEVICE_RANGE_UPPER    GENMASK(31, 16)
>> +#define   HISI_PTT_DEVICE_RANGE_LOWER    GENMASK(15, 0)
>> +#define HISI_PTT_LOCATION        0x0fe8
>> +#define   HISI_PTT_CORE_ID        GENMASK(15, 0)
>> +#define   HISI_PTT_SICL_ID        GENMASK(31, 16)
>> +
>> +/* Parameters of PTT trace DMA part. */
>> +#define HISI_PTT_TRACE_DMA_IRQ            0
>> +#define HISI_PTT_TRACE_BUF_CNT            4
>> +#define HISI_PTT_TRACE_BUF_SIZE            SZ_4M
>> +#define HISI_PTT_TRACE_TOTAL_BUF_SIZE        (HISI_PTT_TRACE_BUF_SIZE * \
>> +                         HISI_PTT_TRACE_BUF_CNT)
>> +/* Wait time for hardware DMA to reset */
>> +#define HISI_PTT_RESET_TIMEOUT_US    10UL
>> +#define HISI_PTT_RESET_POLL_INTERVAL_US    1UL
>> +/* Poll timeout and interval for waiting hardware work to finish */
>> +#define HISI_PTT_WAIT_TRACE_TIMEOUT_US    100UL
>> +#define HISI_PTT_WAIT_POLL_INTERVAL_US    10UL
>> +
>> +#define HISI_PCIE_CORE_PORT_ID(devfn)    (PCI_FUNC(devfn) << 1)
>> +
>> +/* Definition of the PMU configs */
>> +#define HISI_PTT_PMU_FILTER_IS_PORT    BIT(19)
>> +#define HISI_PTT_PMU_FILTER_VAL_MASK    GENMASK(15, 0)
>> +#define HISI_PTT_PMU_DIRECTION_MASK    GENMASK(23, 20)
>> +#define HISI_PTT_PMU_TYPE_MASK        GENMASK(31, 24)
>> +#define HISI_PTT_PMU_FORMAT_MASK    GENMASK(35, 32)
>> +
>> +/**
>> + * struct hisi_ptt_dma_buffer - Describe a single trace buffer of PTT trace.
>> + *                              The detail of the data format is described
>> + *                              in the documentation of PTT device.
>> + * @dma:   DMA address of this buffer visible to the device
>> + * @addr:  virtual address of this buffer visible to the cpu
>> + */
>> +struct hisi_ptt_dma_buffer {
>> +    dma_addr_t dma;
>> +    void *addr;
>> +};
>> +
>> +/**
>> + * struct hisi_ptt_trace_ctrl - Control and status of PTT trace
>> + * @trace_buf: array of the trace buffers for holding the trace data.
>> + *             the length will be HISI_PTT_TRACE_BUF_CNT.
>> + * @handle:    perf output handle of current trace session
>> + * @buf_index: the index of current using trace buffer
>> + * @on_cpu:    current tracing cpu
>> + * @started:   current trace status, true for started
>> + * @is_port:   whether we're tracing root port or not
>> + * @direction: direction of the TLP headers to trace
>> + * @filter:    filter value for tracing the TLP headers
>> + * @format:    format of the TLP headers to trace
>> + * @type:      type of the TLP headers to trace
>> + */
>> +struct hisi_ptt_trace_ctrl {
>> +    struct hisi_ptt_dma_buffer *trace_buf;
>> +    struct perf_output_handle handle;
>> +    u32 buf_index;
>> +    int on_cpu;
>> +    bool started;
>> +    bool is_port;
>> +    u32 direction:2;
>> +    u32 filter:16;
>> +    u32 format:1;
>> +    u32 type:4;
>> +};
>> +
>> +/**
>> + * struct hisi_ptt_filter_desc - Descriptor of the PTT trace filter
>> + * @list:    entry of this descriptor in the filter list
>> + * @is_port: the PCI device of the filter is a Root Port or not
>> + * @devid:   the PCI device's devid of the filter
>> + */
>> +struct hisi_ptt_filter_desc {
>> +    struct list_head list;
>> +    bool is_port;
>> +    u16 devid;
>> +};
>> +
>> +
>> +/**
>> + * struct hisi_ptt_pmu_buf - Descriptor of the AUX buffer of PTT trace
>> + * @length:   size of the AUX buffer
>> + * @nr_pages: number of pages of the AUX buffer
>> + * @base:     start address of AUX buffer
>> + * @pos:      position in the AUX buffer to commit traced data
>> + */
>> +struct hisi_ptt_pmu_buf {
>> +    size_t length;
>> +    int nr_pages;
>> +    void *base;
>> +    long pos;
>> +};
>> +
>> +/**
>> + * struct hisi_ptt - Per PTT device data
>> + * @trace_ctrl:   the control information of PTT trace
>> + * @hotplug_node: node for register cpu hotplug event
>> + * @hisi_ptt_pmu: the pum device of trace
>> + * @iobase:       base IO address of the device
>> + * @pdev:         pci_dev of this PTT device
>> + * @pmu_lock:     lock to serialize the perf process
>> + * @upper_bdf:    the upper BDF range of the PCI devices managed by this PTT device
>> + * @lower_bdf:    the lower BDF range of the PCI devices managed by this PTT device
>> + * @port_filters: the filter list of root ports
>> + * @req_filters:  the filter list of requester ID
>> + * @port_mask:    port mask of the managed root ports
>> + */
>> +struct hisi_ptt {
>> +    struct hisi_ptt_trace_ctrl trace_ctrl;
>> +    struct hlist_node hotplug_node;
>> +    struct pmu hisi_ptt_pmu;
>> +    void __iomem *iobase;
>> +    struct pci_dev *pdev;
>> +    spinlock_t pmu_lock;
>> +    u32 upper_bdf;
>> +    u32 lower_bdf;
>> +
>> +    /*
>> +     * The trace TLP headers can either be filtered by certain
>> +     * root port, or by the requester ID. Organize the filters
>> +     * by @port_filters and @req_filters here. The mask of all
>> +     * the valid ports is also cached for doing sanity check
>> +     * of user input.
>> +     */
>> +    struct list_head port_filters;
>> +    struct list_head req_filters;
>> +    u16 port_mask;
>> +};
>> +
>> +#define to_hisi_ptt(pmu) container_of(pmu, struct hisi_ptt, hisi_ptt_pmu)
>> +
>> +#endif /* _HISI_PTT_H */
> 
> .
John Garry May 17, 2022, 8:21 a.m. UTC | #5
On 17/05/2022 09:09, Yicong Yang wrote:
>>> +    target = cpumask_any(cpumask_of_node(dev_to_node(&hisi_ptt->pdev->dev)));
>>> +    if (target < nr_cpumask_bits) {
>> the comment for cpumask_any() hints to check against nr_cpu_ids - any specific reason to check against nr_cpumask_bits?
>>
> here should be:
> 	if (target >= nr_cpumask_bits) {
> 
> will fix this up.
> 

I am still not sure that using nr_cpumask_bits is correct.
Yicong Yang May 17, 2022, 9:15 a.m. UTC | #6
On 2022/5/17 16:21, John Garry wrote:
> On 17/05/2022 09:09, Yicong Yang wrote:
>>>> +    target = cpumask_any(cpumask_of_node(dev_to_node(&hisi_ptt->pdev->dev)));
>>>> +    if (target < nr_cpumask_bits) {
>>> the comment for cpumask_any() hints to check against nr_cpu_ids - any specific reason to check against nr_cpumask_bits?
>>>
>> here should be:
>>     if (target >= nr_cpumask_bits) {
>>
>> will fix this up.
>>
> 
> I am still not sure that using nr_cpumask_bits is correct.

Let's use nr_cpu_ids to match the comment of cpumask_any(). Actually we should have
nr_cpu_ids(possible cpus, init to NR_CPUS) <= nr_cpumask_bits (NR_CPUS) so it's ok here.
diff mbox series

Patch

diff --git a/drivers/Makefile b/drivers/Makefile
index 020780b6b4d2..662d50599467 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -175,6 +175,7 @@  obj-$(CONFIG_USB4)		+= thunderbolt/
 obj-$(CONFIG_CORESIGHT)		+= hwtracing/coresight/
 obj-y				+= hwtracing/intel_th/
 obj-$(CONFIG_STM)		+= hwtracing/stm/
+obj-$(CONFIG_HISI_PTT)		+= hwtracing/ptt/
 obj-$(CONFIG_ANDROID)		+= android/
 obj-$(CONFIG_NVMEM)		+= nvmem/
 obj-$(CONFIG_FPGA)		+= fpga/
diff --git a/drivers/hwtracing/Kconfig b/drivers/hwtracing/Kconfig
index 13085835a636..911ee977103c 100644
--- a/drivers/hwtracing/Kconfig
+++ b/drivers/hwtracing/Kconfig
@@ -5,4 +5,6 @@  source "drivers/hwtracing/stm/Kconfig"
 
 source "drivers/hwtracing/intel_th/Kconfig"
 
+source "drivers/hwtracing/ptt/Kconfig"
+
 endmenu
diff --git a/drivers/hwtracing/ptt/Kconfig b/drivers/hwtracing/ptt/Kconfig
new file mode 100644
index 000000000000..6d46a09ffeb9
--- /dev/null
+++ b/drivers/hwtracing/ptt/Kconfig
@@ -0,0 +1,12 @@ 
+# SPDX-License-Identifier: GPL-2.0-only
+config HISI_PTT
+	tristate "HiSilicon PCIe Tune and Trace Device"
+	depends on ARM64 || (COMPILE_TEST && 64BIT)
+	depends on PCI && HAS_DMA && HAS_IOMEM && PERF_EVENTS
+	help
+	  HiSilicon PCIe Tune and Trace device exists as a PCIe RCiEP
+	  device, and it provides support for PCIe traffic tuning and
+	  tracing TLP headers to the memory.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called hisi_ptt.
diff --git a/drivers/hwtracing/ptt/Makefile b/drivers/hwtracing/ptt/Makefile
new file mode 100644
index 000000000000..908c09a98161
--- /dev/null
+++ b/drivers/hwtracing/ptt/Makefile
@@ -0,0 +1,2 @@ 
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_HISI_PTT) += hisi_ptt.o
diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c
new file mode 100644
index 000000000000..ef25ce98f664
--- /dev/null
+++ b/drivers/hwtracing/ptt/hisi_ptt.c
@@ -0,0 +1,964 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for HiSilicon PCIe tune and trace device
+ *
+ * Copyright (c) 2022 HiSilicon Technologies Co., Ltd.
+ * Author: Yicong Yang <yangyicong@hisilicon.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/cpuhotplug.h>
+#include <linux/delay.h>
+#include <linux/dma-iommu.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iommu.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/sysfs.h>
+#include <linux/vmalloc.h>
+
+#include "hisi_ptt.h"
+
+/* Dynamic CPU hotplug state used by PTT */
+static enum cpuhp_state hisi_ptt_pmu_online;
+
+static u16 hisi_ptt_get_filter_val(u16 devid, bool is_port)
+{
+	if (is_port)
+		return BIT(HISI_PCIE_CORE_PORT_ID(devid & 0xff));
+
+	return devid;
+}
+
+static bool hisi_ptt_wait_trace_hw_idle(struct hisi_ptt *hisi_ptt)
+{
+	u32 val;
+
+	return !readl_poll_timeout_atomic(hisi_ptt->iobase + HISI_PTT_TRACE_STS,
+					  val, val & HISI_PTT_TRACE_IDLE,
+					  HISI_PTT_WAIT_POLL_INTERVAL_US,
+					  HISI_PTT_WAIT_TRACE_TIMEOUT_US);
+}
+
+static void hisi_ptt_wait_dma_reset_done(struct hisi_ptt *hisi_ptt)
+{
+	u32 val;
+
+	readl_poll_timeout_atomic(hisi_ptt->iobase + HISI_PTT_TRACE_WR_STS,
+				  val, !val, HISI_PTT_RESET_POLL_INTERVAL_US,
+				  HISI_PTT_RESET_TIMEOUT_US);
+}
+
+static void hisi_ptt_trace_end(struct hisi_ptt *hisi_ptt)
+{
+	writel(0, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+	hisi_ptt->trace_ctrl.started = false;
+}
+
+static int hisi_ptt_trace_start(struct hisi_ptt *hisi_ptt)
+{
+	struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
+	u32 val;
+	int i;
+
+	/* Check device idle before start trace */
+	if (!hisi_ptt_wait_trace_hw_idle(hisi_ptt)) {
+		pci_err(hisi_ptt->pdev, "Failed to start trace, the device is still busy\n");
+		return -EBUSY;
+	}
+
+	ctrl->started = true;
+
+	/* Reset the DMA before start tracing */
+	val = readl(hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+	val |= HISI_PTT_TRACE_CTRL_RST;
+	writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+
+	hisi_ptt_wait_dma_reset_done(hisi_ptt);
+
+	val = readl(hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+	val &= ~HISI_PTT_TRACE_CTRL_RST;
+	writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+
+	/* Reset the index of current buffer */
+	hisi_ptt->trace_ctrl.buf_index = 0;
+
+	/* Zero the trace buffers */
+	for (i = 0; i < HISI_PTT_TRACE_BUF_CNT; i++)
+		memset(ctrl->trace_buf[i].addr, 0, HISI_PTT_TRACE_BUF_SIZE);
+
+	/* Clear the interrupt status */
+	writel(HISI_PTT_TRACE_INT_STAT_MASK, hisi_ptt->iobase + HISI_PTT_TRACE_INT_STAT);
+	writel(0, hisi_ptt->iobase + HISI_PTT_TRACE_INT_MASK);
+
+	/* Set the trace control register */
+	val = FIELD_PREP(HISI_PTT_TRACE_CTRL_TYPE_SEL, ctrl->type);
+	val |= FIELD_PREP(HISI_PTT_TRACE_CTRL_RXTX_SEL, ctrl->direction);
+	val |= FIELD_PREP(HISI_PTT_TRACE_CTRL_DATA_FORMAT, ctrl->format);
+	val |= FIELD_PREP(HISI_PTT_TRACE_CTRL_TARGET_SEL, hisi_ptt->trace_ctrl.filter);
+	if (!hisi_ptt->trace_ctrl.is_port)
+		val |= HISI_PTT_TRACE_CTRL_FILTER_MODE;
+
+	/* Start the Trace */
+	val |= HISI_PTT_TRACE_CTRL_EN;
+	writel(val, hisi_ptt->iobase + HISI_PTT_TRACE_CTRL);
+
+	return 0;
+}
+
+static int hisi_ptt_update_aux(struct hisi_ptt *hisi_ptt, int index, bool stop)
+{
+	struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
+	struct perf_output_handle *handle = &ctrl->handle;
+	struct perf_event *event = handle->event;
+	struct hisi_ptt_pmu_buf *buf;
+	size_t size;
+	void *addr;
+
+	buf = perf_get_aux(handle);
+	if (!buf || !handle->size)
+		return -EINVAL;
+
+	addr = ctrl->trace_buf[ctrl->buf_index].addr;
+
+	/*
+	 * If we're going to stop, read the size of already traced data from
+	 * HISI_PTT_TRACE_WR_STS. Otherwise we're coming from the interrupt,
+	 * the data size is always HISI_PTT_TRACE_BUF_SIZE.
+	 */
+	if (stop) {
+		u32 reg;
+
+		reg = readl(hisi_ptt->iobase + HISI_PTT_TRACE_WR_STS);
+		size = FIELD_GET(HISI_PTT_TRACE_WR_STS_WRITE, reg);
+	} else {
+		size = HISI_PTT_TRACE_BUF_SIZE;
+	}
+
+	memcpy(buf->base + buf->pos, addr, size);
+	buf->pos += size;
+
+	/*
+	 * Just commit the traced data if we're going to stop. Otherwise if the
+	 * resident AUX buffer cannot contain the data of next trace buffer,
+	 * apply a new one.
+	 */
+	if (stop) {
+		perf_aux_output_end(handle, buf->pos);
+	} else if (buf->length - buf->pos < HISI_PTT_TRACE_BUF_SIZE) {
+		perf_aux_output_end(handle, buf->pos);
+
+		buf = perf_aux_output_begin(handle, event);
+		if (!buf)
+			return -EINVAL;
+
+		buf->pos = handle->head % buf->length;
+		if (buf->length - buf->pos < HISI_PTT_TRACE_BUF_SIZE) {
+			perf_aux_output_end(handle, 0);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static irqreturn_t hisi_ptt_isr(int irq, void *context)
+{
+	struct hisi_ptt *hisi_ptt = context;
+	u32 status, buf_idx;
+
+	status = readl(hisi_ptt->iobase + HISI_PTT_TRACE_INT_STAT);
+	if (!(status & HISI_PTT_TRACE_INT_STAT_MASK))
+		return IRQ_NONE;
+
+	buf_idx = ffs(status) - 1;
+
+	/* Clear the interrupt status of buffer @buf_idx */
+	writel(status, hisi_ptt->iobase + HISI_PTT_TRACE_INT_STAT);
+
+	/*
+	 * Update the AUX buffer and cache the current buffer index,
+	 * as we need to know this and save the data when the trace
+	 * is ended out of the interrupt handler. End the trace
+	 * if the updating fails.
+	 */
+	if (hisi_ptt_update_aux(hisi_ptt, buf_idx, false))
+		hisi_ptt_trace_end(hisi_ptt);
+	else
+		hisi_ptt->trace_ctrl.buf_index = (buf_idx + 1) % HISI_PTT_TRACE_BUF_CNT;
+
+	return IRQ_HANDLED;
+}
+
+static void hisi_ptt_irq_free_vectors(void *pdev)
+{
+	pci_free_irq_vectors(pdev);
+}
+
+static int hisi_ptt_register_irq(struct hisi_ptt *hisi_ptt)
+{
+	struct pci_dev *pdev = hisi_ptt->pdev;
+	int ret;
+
+	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
+	if (ret < 0) {
+		pci_err(pdev, "failed to allocate irq vector, ret = %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(&pdev->dev, hisi_ptt_irq_free_vectors, pdev);
+	if (ret < 0)
+		return ret;
+
+	ret = devm_request_threaded_irq(&pdev->dev,
+					pci_irq_vector(pdev, HISI_PTT_TRACE_DMA_IRQ),
+					NULL, hisi_ptt_isr, 0,
+					DRV_NAME, hisi_ptt);
+	if (ret) {
+		pci_err(pdev, "failed to request irq %d, ret = %d\n",
+			pci_irq_vector(pdev, HISI_PTT_TRACE_DMA_IRQ), ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int hisi_ptt_init_filters(struct pci_dev *pdev, void *data)
+{
+	struct hisi_ptt_filter_desc *filter;
+	struct hisi_ptt *hisi_ptt = data;
+
+	filter = kzalloc(sizeof(*filter), GFP_KERNEL);
+	if (!filter) {
+		pci_err(hisi_ptt->pdev, "failed to add filter %s\n", pci_name(pdev));
+		return -ENOMEM;
+	}
+
+	filter->devid = PCI_DEVID(pdev->bus->number, pdev->devfn);
+
+	if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT) {
+		filter->is_port = true;
+		list_add_tail(&filter->list, &hisi_ptt->port_filters);
+
+		/* Update the available port mask */
+		hisi_ptt->port_mask |= hisi_ptt_get_filter_val(filter->devid, true);
+	} else {
+		list_add_tail(&filter->list, &hisi_ptt->req_filters);
+	}
+
+	return 0;
+}
+
+static void hisi_ptt_release_filters(void *data)
+{
+	struct hisi_ptt_filter_desc *filter, *tmp;
+	struct hisi_ptt *hisi_ptt = data;
+
+	list_for_each_entry_safe(filter, tmp, &hisi_ptt->req_filters, list) {
+		list_del(&filter->list);
+		kfree(filter);
+	}
+
+	list_for_each_entry_safe(filter, tmp, &hisi_ptt->port_filters, list) {
+		list_del(&filter->list);
+		kfree(filter);
+	}
+}
+
+static int hisi_ptt_config_trace_buf(struct hisi_ptt *hisi_ptt)
+{
+	struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
+	struct device *dev = &hisi_ptt->pdev->dev;
+	int i;
+
+	ctrl->trace_buf = devm_kcalloc(dev, HISI_PTT_TRACE_BUF_CNT,
+				       sizeof(*ctrl->trace_buf), GFP_KERNEL);
+	if (!ctrl->trace_buf)
+		return -ENOMEM;
+
+	for (i = 0; i < HISI_PTT_TRACE_BUF_CNT; ++i) {
+		ctrl->trace_buf[i].addr = dmam_alloc_coherent(dev, HISI_PTT_TRACE_BUF_SIZE,
+							     &ctrl->trace_buf[i].dma,
+							     GFP_KERNEL);
+		if (!ctrl->trace_buf[i].addr)
+			return -ENOMEM;
+	}
+
+	/* Configure the trace DMA buffer */
+	for (i = 0; i < HISI_PTT_TRACE_BUF_CNT; i++) {
+		writel(lower_32_bits(ctrl->trace_buf[i].dma),
+		       hisi_ptt->iobase + HISI_PTT_TRACE_ADDR_BASE_LO_0 +
+		       i * HISI_PTT_TRACE_ADDR_STRIDE);
+		writel(upper_32_bits(ctrl->trace_buf[i].dma),
+		       hisi_ptt->iobase + HISI_PTT_TRACE_ADDR_BASE_HI_0 +
+		       i * HISI_PTT_TRACE_ADDR_STRIDE);
+	}
+	writel(HISI_PTT_TRACE_BUF_SIZE, hisi_ptt->iobase + HISI_PTT_TRACE_ADDR_SIZE);
+
+	return 0;
+}
+
+static int hisi_ptt_init_ctrls(struct hisi_ptt *hisi_ptt)
+{
+	struct pci_dev *pdev = hisi_ptt->pdev;
+	struct pci_bus *bus;
+	int ret;
+	u32 reg;
+
+	INIT_LIST_HEAD(&hisi_ptt->port_filters);
+	INIT_LIST_HEAD(&hisi_ptt->req_filters);
+
+	ret = hisi_ptt_config_trace_buf(hisi_ptt);
+	if (ret)
+		return ret;
+
+	/*
+	 * The device range register provides the information about the
+	 * root ports which the RCiEP can control and trace. The RCiEP
+	 * and the root ports it support are on the same PCIe core, with
+	 * same domain number but maybe different bus number. The device
+	 * range register will tell us which root ports we can support,
+	 * Bit[31:16] indicates the upper BDF numbers of the root port,
+	 * while Bit[15:0] indicates the lower.
+	 */
+	reg = readl(hisi_ptt->iobase + HISI_PTT_DEVICE_RANGE);
+	hisi_ptt->upper_bdf = FIELD_GET(HISI_PTT_DEVICE_RANGE_UPPER, reg);
+	hisi_ptt->lower_bdf = FIELD_GET(HISI_PTT_DEVICE_RANGE_LOWER, reg);
+
+	bus = pci_find_bus(pci_domain_nr(pdev->bus), PCI_BUS_NUM(hisi_ptt->upper_bdf));
+	if (bus)
+		pci_walk_bus(bus, hisi_ptt_init_filters, hisi_ptt);
+
+	ret = devm_add_action_or_reset(&pdev->dev, hisi_ptt_release_filters, hisi_ptt);
+	if (ret)
+		return ret;
+
+	hisi_ptt->trace_ctrl.on_cpu = -1;
+	return 0;
+}
+
+static ssize_t available_root_port_filters_show(struct device *dev,
+						struct device_attribute *attr,
+						char *buf)
+{
+	struct hisi_ptt *hisi_ptt = to_hisi_ptt(dev_get_drvdata(dev));
+	struct hisi_ptt_filter_desc *filter;
+	int pos = 0;
+
+	if (list_empty(&hisi_ptt->port_filters)) {
+		pos = sysfs_emit(buf, "\n");
+		goto out;
+	}
+
+	list_for_each_entry(filter, &hisi_ptt->port_filters, list) {
+		u16 devid = filter->devid;
+		pos += sysfs_emit_at(buf, pos, "%04x:%02x:%02x.%d\t0x%05lx\n",
+				     pci_domain_nr(hisi_ptt->pdev->bus),
+				     PCI_BUS_NUM(devid),
+				     PCI_SLOT(devid & 0xff),
+				     PCI_FUNC(devid & 0xff),
+				     hisi_ptt_get_filter_val(devid, true) |
+				     HISI_PTT_PMU_FILTER_IS_PORT);
+	}
+
+out:
+	return pos;
+}
+static DEVICE_ATTR_ADMIN_RO(available_root_port_filters);
+
+static ssize_t available_requester_filters_show(struct device *dev,
+						struct device_attribute *attr,
+						char *buf)
+{
+	struct hisi_ptt *hisi_ptt = to_hisi_ptt(dev_get_drvdata(dev));
+	struct hisi_ptt_filter_desc *filter;
+	int pos = 0;
+
+	if (list_empty(&hisi_ptt->req_filters)) {
+		pos = sysfs_emit(buf, "\n");
+		goto out;
+	}
+
+	list_for_each_entry(filter, &hisi_ptt->req_filters, list) {
+		u16 devid = filter->devid;
+		pos += sysfs_emit_at(buf, pos, "%04x:%02x:%02x.%d\t0x%05x\n",
+				     pci_domain_nr(hisi_ptt->pdev->bus),
+				     PCI_BUS_NUM(devid),
+				     PCI_SLOT(devid & 0xff),
+				     PCI_FUNC(devid & 0xff),
+				     hisi_ptt_get_filter_val(devid, false));
+	}
+
+out:
+	return pos;
+}
+static DEVICE_ATTR_ADMIN_RO(available_requester_filters);
+
+static ssize_t cpumask_show(struct device *dev, struct device_attribute *attr,
+			    char *buf)
+{
+	struct hisi_ptt *hisi_ptt = to_hisi_ptt(dev_get_drvdata(dev));
+	const cpumask_t *cpumask = cpumask_of_node(dev_to_node(&hisi_ptt->pdev->dev));
+
+	return cpumap_print_to_pagebuf(true, buf, cpumask);
+}
+static DEVICE_ATTR_RO(cpumask);
+
+static struct attribute *hisi_ptt_cpumask_attrs[] = {
+	&dev_attr_cpumask.attr,
+	NULL,
+};
+
+static const struct attribute_group hisi_ptt_cpumask_attr_group = {
+	.attrs = hisi_ptt_cpumask_attrs,
+};
+
+PMU_FORMAT_ATTR(filter,		"config:0-19");
+PMU_FORMAT_ATTR(direction,	"config:20-23");
+PMU_FORMAT_ATTR(type,		"config:24-31");
+PMU_FORMAT_ATTR(format,		"config:32-35");
+
+static struct attribute *hisi_ptt_pmu_format_attrs[] = {
+	&format_attr_filter.attr,
+	&format_attr_direction.attr,
+	&format_attr_type.attr,
+	&format_attr_format.attr,
+	NULL
+};
+
+static struct attribute_group hisi_ptt_pmu_format_group = {
+	.name = "format",
+	.attrs = hisi_ptt_pmu_format_attrs,
+};
+
+static struct attribute *hisi_ptt_pmu_filter_attrs[] = {
+	&dev_attr_available_root_port_filters.attr,
+	&dev_attr_available_requester_filters.attr,
+	NULL
+};
+
+static struct attribute_group hisi_ptt_pmu_filter_group = {
+	.attrs = hisi_ptt_pmu_filter_attrs,
+};
+
+static const struct attribute_group *hisi_ptt_pmu_groups[] = {
+	&hisi_ptt_cpumask_attr_group,
+	&hisi_ptt_pmu_format_group,
+	&hisi_ptt_pmu_filter_group,
+	NULL
+};
+
+static int hisi_ptt_trace_valid_direction(u32 val)
+{
+	/*
+	 * The supported value of the direction parameter. See hisi_ptt.rst
+	 * documentation for more details.
+	 */
+	static const u32 hisi_ptt_trace_available_direction[] = {
+		0,
+		1,
+		2,
+		3,
+	};
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(hisi_ptt_trace_available_direction); i++) {
+		if (val == hisi_ptt_trace_available_direction[i])
+			return 0;
+	}
+
+	return -EINVAL;
+}
+
+static int hisi_ptt_trace_valid_type(u32 val)
+{
+	/* Different types can be set simultaneously */
+	static const u32 hisi_ptt_trace_available_type[] = {
+		1,	/* posted_request */
+		2,	/* non-posted_request */
+		4,	/* completion */
+	};
+	int i;
+
+	if (!val)
+		return -EINVAL;
+
+	/*
+	 * Walk the available list and clear the valid bits of
+	 * the config. If there is any resident bit after the
+	 * walk then the config is invalid.
+	 */
+	for (i = 0; i < ARRAY_SIZE(hisi_ptt_trace_available_type); i++)
+		val &= ~hisi_ptt_trace_available_type[i];
+
+	if (val)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int hisi_ptt_trace_valid_format(u32 val)
+{
+	static const u32 hisi_ptt_trace_availble_format[] = {
+		0,	/* 4DW */
+		1,	/* 8DW */
+	};
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(hisi_ptt_trace_availble_format); i++) {
+		if (val == hisi_ptt_trace_availble_format[i])
+			return 0;
+	}
+
+	return -EINVAL;
+}
+
+static int hisi_ptt_trace_valid_filter(struct hisi_ptt *hisi_ptt, u64 config)
+{
+	unsigned long val, port_mask = hisi_ptt->port_mask;
+	struct hisi_ptt_filter_desc *filter;
+	int ret = -EINVAL;
+
+	hisi_ptt->trace_ctrl.is_port = FIELD_GET(HISI_PTT_PMU_FILTER_IS_PORT, config);
+	val = FIELD_GET(HISI_PTT_PMU_FILTER_VAL_MASK, config);
+
+	/*
+	 * Port filters are defined as bit mask. For port filters, check
+	 * the bits in the @val are within the range of hisi_ptt->port_mask
+	 * and whether it's empty or not, otherwise user has specified
+	 * some unsupported root ports.
+	 *
+	 * For Requester ID filters, walk the available filter list to see
+	 * whether we have one matched.
+	 */
+	if (!hisi_ptt->trace_ctrl.is_port) {
+		list_for_each_entry(filter, &hisi_ptt->req_filters, list) {
+			if (val == hisi_ptt_get_filter_val(filter->devid, filter->is_port)) {
+				ret = 0;
+				break;
+			}
+		}
+	} else if (bitmap_subset(&val, &port_mask, BITS_PER_LONG)) {
+		ret = 0;
+	}
+
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static void hisi_ptt_pmu_init_configs(struct hisi_ptt *hisi_ptt, struct perf_event *event)
+{
+	struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl;
+	u32 val;
+
+	val = FIELD_GET(HISI_PTT_PMU_FILTER_VAL_MASK, event->attr.config);
+	hisi_ptt->trace_ctrl.filter = val;
+
+	val = FIELD_GET(HISI_PTT_PMU_DIRECTION_MASK, event->attr.config);
+	ctrl->direction = val;
+
+	val = FIELD_GET(HISI_PTT_PMU_TYPE_MASK, event->attr.config);
+	ctrl->type = val;
+
+	val = FIELD_GET(HISI_PTT_PMU_FORMAT_MASK, event->attr.config);
+	ctrl->format = val;
+}
+
+static int hisi_ptt_pmu_event_init(struct perf_event *event)
+{
+	struct hisi_ptt *hisi_ptt = to_hisi_ptt(event->pmu);
+	int ret;
+	u32 val;
+
+	if (event->cpu < 0) {
+		dev_dbg(event->pmu->dev, "Per-task mode not supported\n");
+		return -EOPNOTSUPP;
+	}
+
+	if (event->attr.type != hisi_ptt->hisi_ptt_pmu.type)
+		return -ENOENT;
+
+	ret = hisi_ptt_trace_valid_filter(hisi_ptt, event->attr.config);
+	if (ret < 0)
+		return ret;
+
+	val = FIELD_GET(HISI_PTT_PMU_DIRECTION_MASK, event->attr.config);
+	ret = hisi_ptt_trace_valid_direction(val);
+	if (ret < 0)
+		return ret;
+
+	val = FIELD_GET(HISI_PTT_PMU_TYPE_MASK, event->attr.config);
+	ret = hisi_ptt_trace_valid_type(val);
+	if (ret < 0)
+		return ret;
+
+	val = FIELD_GET(HISI_PTT_PMU_FORMAT_MASK, event->attr.config);
+	ret = hisi_ptt_trace_valid_format(val);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static void *hisi_ptt_pmu_setup_aux(struct perf_event *event, void **pages,
+				    int nr_pages, bool overwrite)
+{
+	struct hisi_ptt_pmu_buf *buf;
+	struct page **pagelist;
+	int i;
+
+	if (overwrite) {
+		dev_warn(event->pmu->dev, "Overwrite mode is not supported\n");
+		return NULL;
+	}
+
+	/* If the pages size less than buffers, we cannot start trace */
+	if (nr_pages < HISI_PTT_TRACE_TOTAL_BUF_SIZE / PAGE_SIZE)
+		return NULL;
+
+	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+	if (!buf)
+		return NULL;
+
+	pagelist = kcalloc(nr_pages, sizeof(*pagelist), GFP_KERNEL);
+	if (!pagelist)
+		goto err;
+
+	for (i = 0; i < nr_pages; i++)
+		pagelist[i] = virt_to_page(pages[i]);
+
+	buf->base = vmap(pagelist, nr_pages, VM_MAP, PAGE_KERNEL);
+	if (!buf->base) {
+		kfree(pagelist);
+		goto err;
+	}
+
+	buf->nr_pages = nr_pages;
+	buf->length = nr_pages * PAGE_SIZE;
+	buf->pos = 0;
+
+	kfree(pagelist);
+	return buf;
+err:
+	kfree(buf);
+	return NULL;
+}
+
+static void hisi_ptt_pmu_free_aux(void *aux)
+{
+	struct hisi_ptt_pmu_buf *buf = aux;
+
+	vunmap(buf->base);
+	kfree(buf);
+}
+
+static void hisi_ptt_pmu_start(struct perf_event *event, int flags)
+{
+	struct hisi_ptt *hisi_ptt = to_hisi_ptt(event->pmu);
+	struct perf_output_handle *handle = &hisi_ptt->trace_ctrl.handle;
+	struct hw_perf_event *hwc = &event->hw;
+	struct device *dev = event->pmu->dev;
+	struct hisi_ptt_pmu_buf *buf;
+	int cpu = event->cpu;
+	int ret;
+
+	hwc->state = 0;
+
+	/* Serialize the perf process if user specified several CPUs */
+	spin_lock(&hisi_ptt->pmu_lock);
+	if (hisi_ptt->trace_ctrl.started) {
+		dev_dbg(dev, "trace has already started\n");
+		goto stop;
+	}
+
+	/*
+	 * Handle the interrupt on the same cpu which starts the trace to avoid
+	 * context mismatch. Otherwise we'll trigger the WARN from the perf
+	 * core in event_function_local().
+	 */
+	WARN_ON(irq_set_affinity(pci_irq_vector(hisi_ptt->pdev, HISI_PTT_TRACE_DMA_IRQ),
+				 cpumask_of(cpu)));
+	hisi_ptt->trace_ctrl.on_cpu = cpu;
+
+	buf = perf_aux_output_begin(handle, event);
+	if (!buf) {
+		dev_dbg(dev, "aux output begin failed\n");
+		goto stop;
+	}
+
+	buf->pos = handle->head % buf->length;
+
+	hisi_ptt_pmu_init_configs(hisi_ptt, event);
+
+	ret = hisi_ptt_trace_start(hisi_ptt);
+	if (ret) {
+		dev_dbg(dev, "trace start failed, ret = %d\n", ret);
+		perf_aux_output_end(handle, 0);
+		goto stop;
+	}
+
+	spin_unlock(&hisi_ptt->pmu_lock);
+	return;
+stop:
+	event->hw.state |= PERF_HES_STOPPED;
+	spin_unlock(&hisi_ptt->pmu_lock);
+}
+
+static void hisi_ptt_pmu_stop(struct perf_event *event, int flags)
+{
+	struct hisi_ptt *hisi_ptt = to_hisi_ptt(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+
+	if (hwc->state & PERF_HES_STOPPED)
+		return;
+
+	spin_lock(&hisi_ptt->pmu_lock);
+	if (hisi_ptt->trace_ctrl.started) {
+		hisi_ptt_trace_end(hisi_ptt);
+		WARN(!hisi_ptt_wait_trace_hw_idle(hisi_ptt), "Device is still busy");
+		hisi_ptt_update_aux(hisi_ptt, hisi_ptt->trace_ctrl.buf_index, true);
+	}
+	spin_unlock(&hisi_ptt->pmu_lock);
+
+	hwc->state |= PERF_HES_STOPPED;
+	perf_event_update_userpage(event);
+	hwc->state |= PERF_HES_UPTODATE;
+}
+
+static int hisi_ptt_pmu_add(struct perf_event *event, int flags)
+{
+	struct hisi_ptt *hisi_ptt = to_hisi_ptt(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+	int cpu = event->cpu;
+
+	/* Only allow the cpus on the device's node to add the event */
+	if (!cpumask_test_cpu(cpu, cpumask_of_node(dev_to_node(&hisi_ptt->pdev->dev))))
+		return 0;
+
+	hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+
+	if (flags & PERF_EF_START) {
+		hisi_ptt_pmu_start(event, PERF_EF_RELOAD);
+		if (hwc->state & PERF_HES_STOPPED)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void hisi_ptt_pmu_del(struct perf_event *event, int flags)
+{
+	hisi_ptt_pmu_stop(event, PERF_EF_UPDATE);
+}
+
+static void hisi_ptt_remove_cpuhp_instance(void *hotplug_node)
+{
+	cpuhp_state_remove_instance(hisi_ptt_pmu_online, hotplug_node);
+}
+
+static void hisi_ptt_unregister_pmu(void *pmu)
+{
+	perf_pmu_unregister(pmu);
+}
+
+static int hisi_ptt_register_pmu(struct hisi_ptt *hisi_ptt)
+{
+	u16 core_id, sicl_id;
+	char *pmu_name;
+	u32 reg;
+	int ret;
+
+	ret = cpuhp_state_add_instance(hisi_ptt_pmu_online, &hisi_ptt->hotplug_node);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(&hisi_ptt->pdev->dev,
+				       hisi_ptt_remove_cpuhp_instance,
+				       &hisi_ptt->hotplug_node);
+	if (ret)
+		return ret;
+
+	spin_lock_init(&hisi_ptt->pmu_lock);
+
+	hisi_ptt->hisi_ptt_pmu = (struct pmu) {
+		.module		= THIS_MODULE,
+		.capabilities	= PERF_PMU_CAP_EXCLUSIVE | PERF_PMU_CAP_ITRACE,
+		.task_ctx_nr	= perf_sw_context,
+		.attr_groups	= hisi_ptt_pmu_groups,
+		.event_init	= hisi_ptt_pmu_event_init,
+		.setup_aux	= hisi_ptt_pmu_setup_aux,
+		.free_aux	= hisi_ptt_pmu_free_aux,
+		.start		= hisi_ptt_pmu_start,
+		.stop		= hisi_ptt_pmu_stop,
+		.add		= hisi_ptt_pmu_add,
+		.del		= hisi_ptt_pmu_del,
+	};
+
+	reg = readl(hisi_ptt->iobase + HISI_PTT_LOCATION);
+	core_id = FIELD_GET(HISI_PTT_CORE_ID, reg);
+	sicl_id = FIELD_GET(HISI_PTT_SICL_ID, reg);
+
+	pmu_name = devm_kasprintf(&hisi_ptt->pdev->dev, GFP_KERNEL, "hisi_ptt%u_%u",
+				  sicl_id, core_id);
+	if (!pmu_name)
+		return -ENOMEM;
+
+	ret = perf_pmu_register(&hisi_ptt->hisi_ptt_pmu, pmu_name, -1);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(&hisi_ptt->pdev->dev,
+					hisi_ptt_unregister_pmu,
+					&hisi_ptt->hisi_ptt_pmu);
+}
+
+/*
+ * The DMA of PTT trace can only use direct mapping, due to some
+ * hardware restriction. Check whether there is an IOMMU or the
+ * policy of the IOMMU domain is passthrough, otherwise the trace
+ * cannot work.
+ *
+ * The PTT device is supposed to behind an ARM SMMUv3, which
+ * should have passthrough the device by a quirk.
+ */
+static int hisi_ptt_check_iommu_mapping(struct pci_dev *pdev)
+{
+	struct iommu_domain *iommu_domain;
+
+	iommu_domain = iommu_get_domain_for_dev(&pdev->dev);
+	if (!iommu_domain || iommu_domain->type == IOMMU_DOMAIN_IDENTITY)
+		return 0;
+
+	return -EOPNOTSUPP;
+}
+
+static int hisi_ptt_probe(struct pci_dev *pdev,
+			  const struct pci_device_id *id)
+{
+	struct hisi_ptt *hisi_ptt;
+	int ret;
+
+	ret = hisi_ptt_check_iommu_mapping(pdev);
+	if (ret) {
+		pci_err(pdev, "requires direct DMA mappings\n");
+		return ret;
+	}
+
+	hisi_ptt = devm_kzalloc(&pdev->dev, sizeof(*hisi_ptt), GFP_KERNEL);
+	if (!hisi_ptt)
+		return -ENOMEM;
+
+	hisi_ptt->pdev = pdev;
+	pci_set_drvdata(pdev, hisi_ptt);
+
+	ret = pcim_enable_device(pdev);
+	if (ret) {
+		pci_err(pdev, "failed to enable device, ret = %d\n", ret);
+		return ret;
+	}
+
+	ret = pcim_iomap_regions(pdev, BIT(2), DRV_NAME);
+	if (ret) {
+		pci_err(pdev, "failed to remap io memory, ret = %d\n", ret);
+		return ret;
+	}
+
+	hisi_ptt->iobase = pcim_iomap_table(pdev)[2];
+
+	ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64));
+	if (ret) {
+		pci_err(pdev, "failed to set 64 bit dma mask, ret = %d\n", ret);
+		return ret;
+	}
+
+	pci_set_master(pdev);
+
+	ret = hisi_ptt_register_irq(hisi_ptt);
+	if (ret)
+		return ret;
+
+	ret = hisi_ptt_init_ctrls(hisi_ptt);
+	if (ret) {
+		pci_err(pdev, "failed to init controls, ret = %d\n", ret);
+		return ret;
+	}
+
+	ret = hisi_ptt_register_pmu(hisi_ptt);
+	if (ret) {
+		pci_err(pdev, "failed to register PMU device, ret = %d", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct pci_device_id hisi_ptt_id_tbl[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_HUAWEI, 0xa12e) },
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, hisi_ptt_id_tbl);
+
+static struct pci_driver hisi_ptt_driver = {
+	.name = DRV_NAME,
+	.id_table = hisi_ptt_id_tbl,
+	.probe = hisi_ptt_probe,
+};
+
+static int hisi_ptt_cpu_teardown(unsigned int cpu, struct hlist_node *node)
+{
+	struct hisi_ptt *hisi_ptt;
+	int target, src;
+
+	hisi_ptt = hlist_entry_safe(node, struct hisi_ptt, hotplug_node);
+	src = hisi_ptt->trace_ctrl.on_cpu;
+
+	if (!hisi_ptt->trace_ctrl.started || src != cpu)
+		return 0;
+
+	target = cpumask_any(cpumask_of_node(dev_to_node(&hisi_ptt->pdev->dev)));
+	if (target < nr_cpumask_bits) {
+		dev_err(hisi_ptt->hisi_ptt_pmu.dev, "no available cpu for perf context migration\n");
+		return 0;
+	}
+
+	perf_pmu_migrate_context(&hisi_ptt->hisi_ptt_pmu, src, target);
+	WARN_ON(irq_set_affinity(pci_irq_vector(hisi_ptt->pdev, HISI_PTT_TRACE_DMA_IRQ),
+				 cpumask_of(cpu)));
+	hisi_ptt->trace_ctrl.on_cpu = target;
+
+	return 0;
+}
+
+static int __init hisi_ptt_init(void)
+{
+	int ret;
+
+	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, DRV_NAME, NULL,
+				      hisi_ptt_cpu_teardown);
+	if (ret < 0)
+		return ret;
+	hisi_ptt_pmu_online = ret;
+
+	ret = pci_register_driver(&hisi_ptt_driver);
+	if (ret)
+		cpuhp_remove_multi_state(hisi_ptt_pmu_online);
+
+	return ret;
+}
+module_init(hisi_ptt_init);
+
+static void __exit hisi_ptt_exit(void)
+{
+	pci_unregister_driver(&hisi_ptt_driver);
+	cpuhp_remove_multi_state(hisi_ptt_pmu_online);
+}
+module_exit(hisi_ptt_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Yicong Yang <yangyicong@hisilicon.com>");
+MODULE_DESCRIPTION("Driver for HiSilicon PCIe tune and trace device");
diff --git a/drivers/hwtracing/ptt/hisi_ptt.h b/drivers/hwtracing/ptt/hisi_ptt.h
new file mode 100644
index 000000000000..2344e4195648
--- /dev/null
+++ b/drivers/hwtracing/ptt/hisi_ptt.h
@@ -0,0 +1,178 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Driver for HiSilicon PCIe tune and trace device
+ *
+ * Copyright (c) 2022 HiSilicon Technologies Co., Ltd.
+ * Author: Yicong Yang <yangyicong@hisilicon.com>
+ */
+
+#ifndef _HISI_PTT_H
+#define _HISI_PTT_H
+
+#include <linux/bits.h>
+#include <linux/cpumask.h>
+#include <linux/list.h>
+#include <linux/pci.h>
+#include <linux/perf_event.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#define DRV_NAME "hisi_ptt"
+
+/*
+ * The definition of the device registers and register fields.
+ */
+#define HISI_PTT_TRACE_ADDR_SIZE	0x0800
+#define HISI_PTT_TRACE_ADDR_BASE_LO_0	0x0810
+#define HISI_PTT_TRACE_ADDR_BASE_HI_0	0x0814
+#define HISI_PTT_TRACE_ADDR_STRIDE	0x8
+#define HISI_PTT_TRACE_CTRL		0x0850
+#define   HISI_PTT_TRACE_CTRL_EN	BIT(0)
+#define   HISI_PTT_TRACE_CTRL_RST	BIT(1)
+#define   HISI_PTT_TRACE_CTRL_RXTX_SEL	GENMASK(3, 2)
+#define   HISI_PTT_TRACE_CTRL_TYPE_SEL	GENMASK(7, 4)
+#define   HISI_PTT_TRACE_CTRL_DATA_FORMAT	BIT(14)
+#define   HISI_PTT_TRACE_CTRL_FILTER_MODE	BIT(15)
+#define   HISI_PTT_TRACE_CTRL_TARGET_SEL	GENMASK(31, 16)
+#define HISI_PTT_TRACE_INT_STAT		0x0890
+#define   HISI_PTT_TRACE_INT_STAT_MASK	GENMASK(3, 0)
+#define HISI_PTT_TRACE_INT_MASK		0x0894
+#define HISI_PTT_TRACE_WR_STS		0x08a0
+#define   HISI_PTT_TRACE_WR_STS_WRITE	GENMASK(27, 0)
+#define   HISI_PTT_TRACE_WR_STS_BUFFER	GENMASK(29, 28)
+#define HISI_PTT_TRACE_STS		0x08b0
+#define   HISI_PTT_TRACE_IDLE		BIT(0)
+#define HISI_PTT_DEVICE_RANGE		0x0fe0
+#define   HISI_PTT_DEVICE_RANGE_UPPER	GENMASK(31, 16)
+#define   HISI_PTT_DEVICE_RANGE_LOWER	GENMASK(15, 0)
+#define HISI_PTT_LOCATION		0x0fe8
+#define   HISI_PTT_CORE_ID		GENMASK(15, 0)
+#define   HISI_PTT_SICL_ID		GENMASK(31, 16)
+
+/* Parameters of PTT trace DMA part. */
+#define HISI_PTT_TRACE_DMA_IRQ			0
+#define HISI_PTT_TRACE_BUF_CNT			4
+#define HISI_PTT_TRACE_BUF_SIZE			SZ_4M
+#define HISI_PTT_TRACE_TOTAL_BUF_SIZE		(HISI_PTT_TRACE_BUF_SIZE * \
+						 HISI_PTT_TRACE_BUF_CNT)
+/* Wait time for hardware DMA to reset */
+#define HISI_PTT_RESET_TIMEOUT_US	10UL
+#define HISI_PTT_RESET_POLL_INTERVAL_US	1UL
+/* Poll timeout and interval for waiting hardware work to finish */
+#define HISI_PTT_WAIT_TRACE_TIMEOUT_US	100UL
+#define HISI_PTT_WAIT_POLL_INTERVAL_US	10UL
+
+#define HISI_PCIE_CORE_PORT_ID(devfn)	(PCI_FUNC(devfn) << 1)
+
+/* Definition of the PMU configs */
+#define HISI_PTT_PMU_FILTER_IS_PORT	BIT(19)
+#define HISI_PTT_PMU_FILTER_VAL_MASK	GENMASK(15, 0)
+#define HISI_PTT_PMU_DIRECTION_MASK	GENMASK(23, 20)
+#define HISI_PTT_PMU_TYPE_MASK		GENMASK(31, 24)
+#define HISI_PTT_PMU_FORMAT_MASK	GENMASK(35, 32)
+
+/**
+ * struct hisi_ptt_dma_buffer - Describe a single trace buffer of PTT trace.
+ *                              The detail of the data format is described
+ *                              in the documentation of PTT device.
+ * @dma:   DMA address of this buffer visible to the device
+ * @addr:  virtual address of this buffer visible to the cpu
+ */
+struct hisi_ptt_dma_buffer {
+	dma_addr_t dma;
+	void *addr;
+};
+
+/**
+ * struct hisi_ptt_trace_ctrl - Control and status of PTT trace
+ * @trace_buf: array of the trace buffers for holding the trace data.
+ *             the length will be HISI_PTT_TRACE_BUF_CNT.
+ * @handle:    perf output handle of current trace session
+ * @buf_index: the index of current using trace buffer
+ * @on_cpu:    current tracing cpu
+ * @started:   current trace status, true for started
+ * @is_port:   whether we're tracing root port or not
+ * @direction: direction of the TLP headers to trace
+ * @filter:    filter value for tracing the TLP headers
+ * @format:    format of the TLP headers to trace
+ * @type:      type of the TLP headers to trace
+ */
+struct hisi_ptt_trace_ctrl {
+	struct hisi_ptt_dma_buffer *trace_buf;
+	struct perf_output_handle handle;
+	u32 buf_index;
+	int on_cpu;
+	bool started;
+	bool is_port;
+	u32 direction:2;
+	u32 filter:16;
+	u32 format:1;
+	u32 type:4;
+};
+
+/**
+ * struct hisi_ptt_filter_desc - Descriptor of the PTT trace filter
+ * @list:    entry of this descriptor in the filter list
+ * @is_port: the PCI device of the filter is a Root Port or not
+ * @devid:   the PCI device's devid of the filter
+ */
+struct hisi_ptt_filter_desc {
+	struct list_head list;
+	bool is_port;
+	u16 devid;
+};
+
+
+/**
+ * struct hisi_ptt_pmu_buf - Descriptor of the AUX buffer of PTT trace
+ * @length:   size of the AUX buffer
+ * @nr_pages: number of pages of the AUX buffer
+ * @base:     start address of AUX buffer
+ * @pos:      position in the AUX buffer to commit traced data
+ */
+struct hisi_ptt_pmu_buf {
+	size_t length;
+	int nr_pages;
+	void *base;
+	long pos;
+};
+
+/**
+ * struct hisi_ptt - Per PTT device data
+ * @trace_ctrl:   the control information of PTT trace
+ * @hotplug_node: node for register cpu hotplug event
+ * @hisi_ptt_pmu: the pum device of trace
+ * @iobase:       base IO address of the device
+ * @pdev:         pci_dev of this PTT device
+ * @pmu_lock:     lock to serialize the perf process
+ * @upper_bdf:    the upper BDF range of the PCI devices managed by this PTT device
+ * @lower_bdf:    the lower BDF range of the PCI devices managed by this PTT device
+ * @port_filters: the filter list of root ports
+ * @req_filters:  the filter list of requester ID
+ * @port_mask:    port mask of the managed root ports
+ */
+struct hisi_ptt {
+	struct hisi_ptt_trace_ctrl trace_ctrl;
+	struct hlist_node hotplug_node;
+	struct pmu hisi_ptt_pmu;
+	void __iomem *iobase;
+	struct pci_dev *pdev;
+	spinlock_t pmu_lock;
+	u32 upper_bdf;
+	u32 lower_bdf;
+
+	/*
+	 * The trace TLP headers can either be filtered by certain
+	 * root port, or by the requester ID. Organize the filters
+	 * by @port_filters and @req_filters here. The mask of all
+	 * the valid ports is also cached for doing sanity check
+	 * of user input.
+	 */
+	struct list_head port_filters;
+	struct list_head req_filters;
+	u16 port_mask;
+};
+
+#define to_hisi_ptt(pmu) container_of(pmu, struct hisi_ptt, hisi_ptt_pmu)
+
+#endif /* _HISI_PTT_H */