diff mbox

[V8,1/8] ACPI: I/O Remapping Table (IORT) initial support

Message ID 1470909998-16710-2-git-send-email-tn@semihalf.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Tomasz Nowicki Aug. 11, 2016, 10:06 a.m. UTC 
IORT shows representation of IO topology for ARM based systems.
It describes how various components are connected together on
parent-child basis e.g. PCI RC -> SMMU -> ITS. Also see IORT spec.
http://infocenter.arm.com/help/topic/com.arm.doc.den0049b/DEN0049B_IO_Remapping_Table.pdf

Initial support allows to detect IORT table presence and save its
root pointer obtained through acpi_get_table(). The pointer validity
depends on acpi_gbl_permanent_mmap because if acpi_gbl_permanent_mmap
is not set while using IORT nodes we would dereference unmapped pointers.

For the aforementioned reason call iort_table_detect() from acpi_init()
which guarantees acpi_gbl_permanent_mmap to be set at that point.

Add generic helpers which are helpful for scanning and retrieving
information from IORT table content. List of the most important helpers:
- iort_find_dev_node() finds IORT node for a given device
- iort_node_map_rid() maps device RID and returns IORT node which provides
  final translation

IORT support is placed under drivers/acpi/arm64/ new directory due to its
ARM64 specific nature. The code there is considered only for ARM64.
The long term plan is to keep all ARM64 specific tables support
in this place e.g. GTDT table.

Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
---
 drivers/acpi/Kconfig        |   5 +
 drivers/acpi/Makefile       |   2 +
 drivers/acpi/arm64/Kconfig  |   6 ++
 drivers/acpi/arm64/Makefile |   1 +
 drivers/acpi/arm64/iort.c   | 218 ++++++++++++++++++++++++++++++++++++++++++++
 drivers/acpi/bus.c          |   2 +
 include/linux/iort.h        |  30 ++++++
 7 files changed, 264 insertions(+)
 create mode 100644 drivers/acpi/arm64/Kconfig
 create mode 100644 drivers/acpi/arm64/Makefile
 create mode 100644 drivers/acpi/arm64/iort.c
 create mode 100644 include/linux/iort.h

Comments

Lorenzo Pieralisi Aug. 12, 2016, 4:33 p.m. UTC | #1 
Hi Tomasz,

On Thu, Aug 11, 2016 at 12:06:31PM +0200, Tomasz Nowicki wrote:
> IORT shows representation of IO topology for ARM based systems.
> It describes how various components are connected together on
> parent-child basis e.g. PCI RC -> SMMU -> ITS. Also see IORT spec.
> http://infocenter.arm.com/help/topic/com.arm.doc.den0049b/DEN0049B_IO_Remapping_Table.pdf
> 
> Initial support allows to detect IORT table presence and save its
> root pointer obtained through acpi_get_table(). The pointer validity
> depends on acpi_gbl_permanent_mmap because if acpi_gbl_permanent_mmap
> is not set while using IORT nodes we would dereference unmapped pointers.
> 
> For the aforementioned reason call iort_table_detect() from acpi_init()
> which guarantees acpi_gbl_permanent_mmap to be set at that point.

We still need to get Rafael ACK on this, keeping in mind that the
eg code parsing DMAR table relies on the same assumption.

[...]

> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> index 445ce28..6cef2d1 100644
> --- a/drivers/acpi/Kconfig
> +++ b/drivers/acpi/Kconfig
> @@ -521,4 +521,9 @@ config ACPI_CONFIGFS
>  	  userspace. The configurable ACPI groups will be visible under
>  	  /config/acpi, assuming configfs is mounted under /config.
>  
> +if ARM64
> +source "drivers/acpi/arm64/Kconfig"
> +

Just curious: Why do you need a space ?

> +endif
> +
>  endif	# ACPI
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index 5ae9d85..e5ada78 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -105,3 +105,5 @@ obj-$(CONFIG_ACPI_CONFIGFS)	+= acpi_configfs.o
>  
>  video-objs			+= acpi_video.o video_detect.o
>  obj-y				+= dptf/
> +
> +obj-$(CONFIG_ARM64)		+= arm64/
> diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
> new file mode 100644
> index 0000000..fc818dc
> --- /dev/null
> +++ b/drivers/acpi/arm64/Kconfig
> @@ -0,0 +1,6 @@
> +#
> +# ACPI Configuration for ARM64
> +#
> +
> +config IORT_TABLE
> +	bool
> diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
> new file mode 100644
> index 0000000..d01be6f
> --- /dev/null
> +++ b/drivers/acpi/arm64/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_IORT_TABLE) 	+= iort.o
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> new file mode 100644
> index 0000000..f89056e
> --- /dev/null
> +++ b/drivers/acpi/arm64/iort.c
> @@ -0,0 +1,218 @@
> +/*
> + * Copyright (C) 2016, Semihalf
> + *	Author: Tomasz Nowicki <tn@semihalf.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * This file implements early detection/parsing of I/O mapping
> + * reported to OS through firmware via I/O Remapping Table (IORT)
> + * IORT document number: ARM DEN 0049A
> + */
> +
> +#define pr_fmt(fmt)	"ACPI: IORT: " fmt
> +
> +#include <linux/iort.h>
> +#include <linux/kernel.h>
> +#include <linux/pci.h>
> +
> +typedef acpi_status (*iort_find_node_callback)
> +	(struct acpi_iort_node *node, void *context);
> +
> +/* Root pointer to the mapped IORT table */
> +static struct acpi_table_header *iort_table;

See above.

[...]

> +void __init iort_table_detect(void)
> +{
> +	acpi_status status;
> +
> +	status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table);
> +	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
> +		const char *msg = acpi_format_exception(status);
> +		pr_err("Failed to get table, %s\n", msg);
> +	}
> +}
> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> index 85b7d07..55a84da 100644
> --- a/drivers/acpi/bus.c
> +++ b/drivers/acpi/bus.c
> @@ -36,6 +36,7 @@
>  #ifdef CONFIG_X86
>  #include <asm/mpspec.h>
>  #endif
> +#include <linux/iort.h>
>  #include <linux/pci.h>
>  #include <acpi/apei.h>
>  #include <linux/dmi.h>
> @@ -1186,6 +1187,7 @@ static int __init acpi_init(void)
>  	}
>  
>  	pci_mmcfg_late_init();
> +	iort_table_detect();

That's another bit we have to make sure Rafael is ok with, given
that IORT is ARM64 specific (but we stub it out if it is not
configured).

Having said that:

Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

>  	acpi_scan_init();
>  	acpi_ec_init();
>  	acpi_debugfs_init();
> diff --git a/include/linux/iort.h b/include/linux/iort.h
> new file mode 100644
> index 0000000..cde6809
> --- /dev/null
> +++ b/include/linux/iort.h
> @@ -0,0 +1,30 @@
> +/*
> + * Copyright (C) 2016, Semihalf
> + *	Author: Tomasz Nowicki <tn@semihalf.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
> + * Place - Suite 330, Boston, MA 02111-1307 USA.
> + */
> +
> +#ifndef __IORT_H__
> +#define __IORT_H__
> +
> +#include <linux/acpi.h>
> +
> +#ifdef CONFIG_IORT_TABLE
> +void iort_table_detect(void);
> +#else
> +static inline void iort_table_detect(void) { }
> +#endif
> +
> +#endif /* __IORT_H__ */
> -- 
> 1.9.1
> 
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Tomasz Nowicki Aug. 18, 2016, 6:25 a.m. UTC | #2 
On 12.08.2016 18:33, Lorenzo Pieralisi wrote:
> Hi Tomasz,
>
> On Thu, Aug 11, 2016 at 12:06:31PM +0200, Tomasz Nowicki wrote:
>> IORT shows representation of IO topology for ARM based systems.
>> It describes how various components are connected together on
>> parent-child basis e.g. PCI RC -> SMMU -> ITS. Also see IORT spec.
>> http://infocenter.arm.com/help/topic/com.arm.doc.den0049b/DEN0049B_IO_Remapping_Table.pdf
>>
>> Initial support allows to detect IORT table presence and save its
>> root pointer obtained through acpi_get_table(). The pointer validity
>> depends on acpi_gbl_permanent_mmap because if acpi_gbl_permanent_mmap
>> is not set while using IORT nodes we would dereference unmapped pointers.
>>
>> For the aforementioned reason call iort_table_detect() from acpi_init()
>> which guarantees acpi_gbl_permanent_mmap to be set at that point.
>
> We still need to get Rafael ACK on this, keeping in mind that the
> eg code parsing DMAR table relies on the same assumption.

Exactly.

Rafael, can you please have a look ?

>
> [...]
>
>> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
>> index 445ce28..6cef2d1 100644
>> --- a/drivers/acpi/Kconfig
>> +++ b/drivers/acpi/Kconfig
>> @@ -521,4 +521,9 @@ config ACPI_CONFIGFS
>>  	  userspace. The configurable ACPI groups will be visible under
>>  	  /config/acpi, assuming configfs is mounted under /config.
>>
>> +if ARM64
>> +source "drivers/acpi/arm64/Kconfig"
>> +
>
> Just curious: Why do you need a space ?

No good reason, it will disappear for next version.

>
>> +endif
>> +
>>  endif	# ACPI
>> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
>> index 5ae9d85..e5ada78 100644
>> --- a/drivers/acpi/Makefile
>> +++ b/drivers/acpi/Makefile
>> @@ -105,3 +105,5 @@ obj-$(CONFIG_ACPI_CONFIGFS)	+= acpi_configfs.o
>>
>>  video-objs			+= acpi_video.o video_detect.o
>>  obj-y				+= dptf/
>> +
>> +obj-$(CONFIG_ARM64)		+= arm64/
>> diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
>> new file mode 100644
>> index 0000000..fc818dc
>> --- /dev/null
>> +++ b/drivers/acpi/arm64/Kconfig
>> @@ -0,0 +1,6 @@
>> +#
>> +# ACPI Configuration for ARM64
>> +#
>> +
>> +config IORT_TABLE
>> +	bool
>> diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
>> new file mode 100644
>> index 0000000..d01be6f
>> --- /dev/null
>> +++ b/drivers/acpi/arm64/Makefile
>> @@ -0,0 +1 @@
>> +obj-$(CONFIG_IORT_TABLE) 	+= iort.o
>> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
>> new file mode 100644
>> index 0000000..f89056e
>> --- /dev/null
>> +++ b/drivers/acpi/arm64/iort.c
>> @@ -0,0 +1,218 @@
>> +/*
>> + * Copyright (C) 2016, Semihalf
>> + *	Author: Tomasz Nowicki <tn@semihalf.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify it
>> + * under the terms and conditions of the GNU General Public License,
>> + * version 2, as published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope it will be useful, but WITHOUT
>> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
>> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
>> + * more details.
>> + *
>> + * This file implements early detection/parsing of I/O mapping
>> + * reported to OS through firmware via I/O Remapping Table (IORT)
>> + * IORT document number: ARM DEN 0049A
>> + */
>> +
>> +#define pr_fmt(fmt)	"ACPI: IORT: " fmt
>> +
>> +#include <linux/iort.h>
>> +#include <linux/kernel.h>
>> +#include <linux/pci.h>
>> +
>> +typedef acpi_status (*iort_find_node_callback)
>> +	(struct acpi_iort_node *node, void *context);
>> +
>> +/* Root pointer to the mapped IORT table */
>> +static struct acpi_table_header *iort_table;
>
> See above.
>
> [...]
>
>> +void __init iort_table_detect(void)
>> +{
>> +	acpi_status status;
>> +
>> +	status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table);
>> +	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
>> +		const char *msg = acpi_format_exception(status);
>> +		pr_err("Failed to get table, %s\n", msg);
>> +	}
>> +}
>> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
>> index 85b7d07..55a84da 100644
>> --- a/drivers/acpi/bus.c
>> +++ b/drivers/acpi/bus.c
>> @@ -36,6 +36,7 @@
>>  #ifdef CONFIG_X86
>>  #include <asm/mpspec.h>
>>  #endif
>> +#include <linux/iort.h>
>>  #include <linux/pci.h>
>>  #include <acpi/apei.h>
>>  #include <linux/dmi.h>
>> @@ -1186,6 +1187,7 @@ static int __init acpi_init(void)
>>  	}
>>
>>  	pci_mmcfg_late_init();
>> +	iort_table_detect();
>
> That's another bit we have to make sure Rafael is ok with, given
> that IORT is ARM64 specific (but we stub it out if it is not
> configured).
>
> Having said that:
>
> Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

Thanks for your time.

Tomasz
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Dennis Chen Aug. 18, 2016, 10:55 a.m. UTC | #3 
Hi Tomasz,

On Thu, Aug 11, 2016 at 12:06:31PM +0200, Tomasz Nowicki wrote:
> IORT shows representation of IO topology for ARM based systems.
> It describes how various components are connected together on
> parent-child basis e.g. PCI RC -> SMMU -> ITS. Also see IORT spec.
> http://infocenter.arm.com/help/topic/com.arm.doc.den0049b/DEN0049B_IO_Remapping_Table.pdf
> 
> Initial support allows to detect IORT table presence and save its
> root pointer obtained through acpi_get_table(). The pointer validity
> depends on acpi_gbl_permanent_mmap because if acpi_gbl_permanent_mmap
> is not set while using IORT nodes we would dereference unmapped pointers.
> 
> For the aforementioned reason call iort_table_detect() from acpi_init()
> which guarantees acpi_gbl_permanent_mmap to be set at that point.
> 
> Add generic helpers which are helpful for scanning and retrieving
> information from IORT table content. List of the most important helpers:
> - iort_find_dev_node() finds IORT node for a given device
> - iort_node_map_rid() maps device RID and returns IORT node which provides
>   final translation
> 
> IORT support is placed under drivers/acpi/arm64/ new directory due to its
> ARM64 specific nature. The code there is considered only for ARM64.
> The long term plan is to keep all ARM64 specific tables support
> in this place e.g. GTDT table.
> 
> Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
> ---
>  drivers/acpi/Kconfig        |   5 +
>  drivers/acpi/Makefile       |   2 +
>  drivers/acpi/arm64/Kconfig  |   6 ++
>  drivers/acpi/arm64/Makefile |   1 +
>  drivers/acpi/arm64/iort.c   | 218 ++++++++++++++++++++++++++++++++++++++++++++
>  drivers/acpi/bus.c          |   2 +
>  include/linux/iort.h        |  30 ++++++
>  7 files changed, 264 insertions(+)
>  create mode 100644 drivers/acpi/arm64/Kconfig
>  create mode 100644 drivers/acpi/arm64/Makefile
>  create mode 100644 drivers/acpi/arm64/iort.c
>  create mode 100644 include/linux/iort.h
> 
> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> index 445ce28..6cef2d1 100644
> --- a/drivers/acpi/Kconfig
> +++ b/drivers/acpi/Kconfig
> @@ -521,4 +521,9 @@ config ACPI_CONFIGFS
>  	  userspace. The configurable ACPI groups will be visible under
>  	  /config/acpi, assuming configfs is mounted under /config.
>  
> +if ARM64
> +source "drivers/acpi/arm64/Kconfig"
> +
> +endif
> +
>  endif	# ACPI
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index 5ae9d85..e5ada78 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -105,3 +105,5 @@ obj-$(CONFIG_ACPI_CONFIGFS)	+= acpi_configfs.o
>  
>  video-objs			+= acpi_video.o video_detect.o
>  obj-y				+= dptf/
> +
> +obj-$(CONFIG_ARM64)		+= arm64/
> diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
> new file mode 100644
> index 0000000..fc818dc
> --- /dev/null
> +++ b/drivers/acpi/arm64/Kconfig
> @@ -0,0 +1,6 @@
> +#
> +# ACPI Configuration for ARM64
> +#
> +
> +config IORT_TABLE
> +	bool
> diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
> new file mode 100644
> index 0000000..d01be6f
> --- /dev/null
> +++ b/drivers/acpi/arm64/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_IORT_TABLE) 	+= iort.o
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> new file mode 100644
> index 0000000..f89056e
> --- /dev/null
> +++ b/drivers/acpi/arm64/iort.c
> @@ -0,0 +1,218 @@
> +/*
> + * Copyright (C) 2016, Semihalf
> + *	Author: Tomasz Nowicki <tn@semihalf.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * This file implements early detection/parsing of I/O mapping
> + * reported to OS through firmware via I/O Remapping Table (IORT)
> + * IORT document number: ARM DEN 0049A
> + */
> +
> +#define pr_fmt(fmt)	"ACPI: IORT: " fmt
> +
> +#include <linux/iort.h>
> +#include <linux/kernel.h>
> +#include <linux/pci.h>
> +
> +typedef acpi_status (*iort_find_node_callback)
> +	(struct acpi_iort_node *node, void *context);
> +
> +/* Root pointer to the mapped IORT table */
> +static struct acpi_table_header *iort_table;
> +
> +static struct acpi_iort_node *
> +iort_scan_node(enum acpi_iort_node_type type,
> +	       iort_find_node_callback callback, void *context)
> +{
> +	struct acpi_iort_node *iort_node, *iort_end;
> +	struct acpi_table_iort *iort;
> +	int i;
> +
> +	/* Get the first IORT node */
> +	iort = (struct acpi_table_iort *)iort_table;
>
Here, the same as I comments on Lorenzo's patch. If IORT is missed in the firmware,
then iort_table will be NULL, result in kernel panic in the codes followed.

Thanks,
Dennis
> +	iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort,
> +				 iort->node_offset);
> +	iort_end = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
> +				iort_table->length);
> +
> +	for (i = 0; i < iort->node_count; i++) {
> +		if (WARN_TAINT(iort_node >= iort_end, TAINT_FIRMWARE_WORKAROUND,
> +			       "IORT node pointer overflows, bad table!\n"))
> +			return NULL;
> +
> +		if (iort_node->type == type) {
> +			if (ACPI_SUCCESS(callback(iort_node, context)))
> +				return iort_node;
> +		}
> +
> +		iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node,
> +					 iort_node->length);
> +	}
> +
> +	return NULL;
> +}
> +
> +static acpi_status
> +iort_match_node_callback(struct acpi_iort_node *node, void *context)
> +{
> +	struct device *dev = context;
> +
> +	switch (node->type) {
> +	case ACPI_IORT_NODE_NAMED_COMPONENT: {
> +		struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
> +		struct acpi_device *adev = to_acpi_device_node(dev->fwnode);
> +		struct acpi_iort_named_component *ncomp;
> +
> +		if (!adev)
> +			break;
> +
> +		ncomp = (struct acpi_iort_named_component *)node->node_data;
> +
> +		if (ACPI_FAILURE(acpi_get_name(adev->handle,
> +					       ACPI_FULL_PATHNAME, &buffer))) {
> +			dev_warn(dev, "Can't get device full path name\n");
> +		} else {
> +			int match;
> +
> +			match = !strcmp(ncomp->device_name, buffer.pointer);
> +			acpi_os_free(buffer.pointer);
> +
> +			if (match)
> +				return AE_OK;
> +		}
> +
> +		break;
> +	}
> +	case ACPI_IORT_NODE_PCI_ROOT_COMPLEX: {
> +		struct acpi_iort_root_complex *pci_rc;
> +		struct pci_bus *bus;
> +
> +		bus = to_pci_bus(dev);
> +		pci_rc = (struct acpi_iort_root_complex *)node->node_data;
> +
> +		/*
> +		 * It is assumed that PCI segment numbers maps one-to-one
> +		 * with root complexes. Each segment number can represent only
> +		 * one root complex.
> +		 */
> +		if (pci_rc->pci_segment_number == pci_domain_nr(bus))
> +			return AE_OK;
> +
> +		break;
> +	}
> +	}
> +
> +	return AE_NOT_FOUND;
> +}
> +
> +static int
> +iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in, u32 *rid_out)
> +{
> +	/* Single mapping does not care for input id */
> +	if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
> +		if (type == ACPI_IORT_NODE_NAMED_COMPONENT ||
> +		    type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
> +			*rid_out = map->output_base;
> +			return 0;
> +		}
> +
> +		pr_warn(FW_BUG "[map %p] SINGLE MAPPING flag not allowed for node type %d, skipping ID map\n",
> +			map, type);
> +		return -ENXIO;
> +	}
> +
> +	if (rid_in < map->input_base ||
> +	    (rid_in >= map->input_base + map->id_count))
> +		return -ENXIO;
> +
> +	*rid_out = map->output_base + (rid_in - map->input_base);
> +	return 0;
> +}
> +
> +static struct acpi_iort_node *
> +iort_node_map_rid(struct acpi_iort_node *node, u32 rid_in,
> +		  u32 *rid_out, u8 type)
> +{
> +	u32 rid = rid_in;
> +
> +	/* Parse the ID mapping tree to find specified node type */
> +	while (node) {
> +		struct acpi_iort_id_mapping *map;
> +		int i;
> +
> +		if (node->type == type) {
> +			if (rid_out)
> +				*rid_out = rid;
> +			return node;
> +		}
> +
> +		if (!node->mapping_offset || !node->mapping_count)
> +			goto fail_map;
> +
> +		map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
> +				   node->mapping_offset);
> +
> +		/* Firmware bug! */
> +		if (!map->output_reference) {
> +			pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n",
> +			       node, node->type);
> +			goto fail_map;
> +		}
> +
> +		/* Do the RID translation */
> +		for (i = 0; i < node->mapping_count; i++, map++) {
> +			if (!iort_id_map(map, node->type, rid, &rid))
> +				break;
> +		}
> +
> +		if (i == node->mapping_count)
> +			goto fail_map;
> +
> +		node = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
> +				    map->output_reference);
> +	}
> +
> +fail_map:
> +	/* Map input RID to output RID unchanged on mapping failure*/
> +	if (rid_out)
> +		*rid_out = rid_in;
> +
> +	return NULL;
> +}
> +
> +static struct acpi_iort_node *
> +iort_find_dev_node(struct device *dev)
> +{
> +	struct pci_bus *pbus;
> +
> +	if (!dev_is_pci(dev))
> +		return iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
> +				      iort_match_node_callback, dev);
> +
> +	/* Find a PCI root bus */
> +	pbus = to_pci_dev(dev)->bus;
> +	while (!pci_is_root_bus(pbus))
> +		pbus = pbus->parent;
> +
> +	return iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
> +			      iort_match_node_callback, &pbus->dev);
> +}
> +
> +void __init iort_table_detect(void)
> +{
> +	acpi_status status;
> +
> +	status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table);
> +	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
> +		const char *msg = acpi_format_exception(status);
> +		pr_err("Failed to get table, %s\n", msg);
> +	}
> +}
> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> index 85b7d07..55a84da 100644
> --- a/drivers/acpi/bus.c
> +++ b/drivers/acpi/bus.c
> @@ -36,6 +36,7 @@
>  #ifdef CONFIG_X86
>  #include <asm/mpspec.h>
>  #endif
> +#include <linux/iort.h>
>  #include <linux/pci.h>
>  #include <acpi/apei.h>
>  #include <linux/dmi.h>
> @@ -1186,6 +1187,7 @@ static int __init acpi_init(void)
>  	}
>  
>  	pci_mmcfg_late_init();
> +	iort_table_detect();
>  	acpi_scan_init();
>  	acpi_ec_init();
>  	acpi_debugfs_init();
> diff --git a/include/linux/iort.h b/include/linux/iort.h
> new file mode 100644
> index 0000000..cde6809
> --- /dev/null
> +++ b/include/linux/iort.h
> @@ -0,0 +1,30 @@
> +/*
> + * Copyright (C) 2016, Semihalf
> + *	Author: Tomasz Nowicki <tn@semihalf.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
> + * Place - Suite 330, Boston, MA 02111-1307 USA.
> + */
> +
> +#ifndef __IORT_H__
> +#define __IORT_H__
> +
> +#include <linux/acpi.h>
> +
> +#ifdef CONFIG_IORT_TABLE
> +void iort_table_detect(void);
> +#else
> +static inline void iort_table_detect(void) { }
> +#endif
> +
> +#endif /* __IORT_H__ */
> -- 
> 1.9.1
> 
> --
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> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

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Lorenzo Pieralisi Aug. 18, 2016, 11:14 a.m. UTC | #4 
On Thu, Aug 18, 2016 at 06:55:50PM +0800, Dennis Chen wrote:

[...]

> > +static struct acpi_iort_node *
> > +iort_scan_node(enum acpi_iort_node_type type,
> > +	       iort_find_node_callback callback, void *context)
> > +{
> > +	struct acpi_iort_node *iort_node, *iort_end;
> > +	struct acpi_table_iort *iort;
> > +	int i;
> > +
> > +	/* Get the first IORT node */
> > +	iort = (struct acpi_table_iort *)iort_table;
> >
> Here, the same as I comments on Lorenzo's patch. If IORT is missed in
> the firmware, then iort_table will be NULL, result in kernel panic in
> the codes followed.

The pointer is checked in the functions that are visible to
other compilation units before calling this function:

iort_msi_map_rid()
iort_get_device_domain()

I missed to check it when I added iort_node_match() and
iort_iommu_configure() though, which makes me think that it is probably
better to move the iort_table pointer check to iort_scan_node() so that
it is done in one single place instead of adding it to all given
external interfaces.

Lorenzo

> 
> Thanks,
> Dennis
> > +	iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort,
> > +				 iort->node_offset);
> > +	iort_end = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
> > +				iort_table->length);
> > +
> > +	for (i = 0; i < iort->node_count; i++) {
> > +		if (WARN_TAINT(iort_node >= iort_end, TAINT_FIRMWARE_WORKAROUND,
> > +			       "IORT node pointer overflows, bad table!\n"))
> > +			return NULL;
> > +
> > +		if (iort_node->type == type) {
> > +			if (ACPI_SUCCESS(callback(iort_node, context)))
> > +				return iort_node;
> > +		}
> > +
> > +		iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node,
> > +					 iort_node->length);
> > +	}
> > +
> > +	return NULL;
> > +}
> > +
> > +static acpi_status
> > +iort_match_node_callback(struct acpi_iort_node *node, void *context)
> > +{
> > +	struct device *dev = context;
> > +
> > +	switch (node->type) {
> > +	case ACPI_IORT_NODE_NAMED_COMPONENT: {
> > +		struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
> > +		struct acpi_device *adev = to_acpi_device_node(dev->fwnode);
> > +		struct acpi_iort_named_component *ncomp;
> > +
> > +		if (!adev)
> > +			break;
> > +
> > +		ncomp = (struct acpi_iort_named_component *)node->node_data;
> > +
> > +		if (ACPI_FAILURE(acpi_get_name(adev->handle,
> > +					       ACPI_FULL_PATHNAME, &buffer))) {
> > +			dev_warn(dev, "Can't get device full path name\n");
> > +		} else {
> > +			int match;
> > +
> > +			match = !strcmp(ncomp->device_name, buffer.pointer);
> > +			acpi_os_free(buffer.pointer);
> > +
> > +			if (match)
> > +				return AE_OK;
> > +		}
> > +
> > +		break;
> > +	}
> > +	case ACPI_IORT_NODE_PCI_ROOT_COMPLEX: {
> > +		struct acpi_iort_root_complex *pci_rc;
> > +		struct pci_bus *bus;
> > +
> > +		bus = to_pci_bus(dev);
> > +		pci_rc = (struct acpi_iort_root_complex *)node->node_data;
> > +
> > +		/*
> > +		 * It is assumed that PCI segment numbers maps one-to-one
> > +		 * with root complexes. Each segment number can represent only
> > +		 * one root complex.
> > +		 */
> > +		if (pci_rc->pci_segment_number == pci_domain_nr(bus))
> > +			return AE_OK;
> > +
> > +		break;
> > +	}
> > +	}
> > +
> > +	return AE_NOT_FOUND;
> > +}
> > +
> > +static int
> > +iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in, u32 *rid_out)
> > +{
> > +	/* Single mapping does not care for input id */
> > +	if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
> > +		if (type == ACPI_IORT_NODE_NAMED_COMPONENT ||
> > +		    type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
> > +			*rid_out = map->output_base;
> > +			return 0;
> > +		}
> > +
> > +		pr_warn(FW_BUG "[map %p] SINGLE MAPPING flag not allowed for node type %d, skipping ID map\n",
> > +			map, type);
> > +		return -ENXIO;
> > +	}
> > +
> > +	if (rid_in < map->input_base ||
> > +	    (rid_in >= map->input_base + map->id_count))
> > +		return -ENXIO;
> > +
> > +	*rid_out = map->output_base + (rid_in - map->input_base);
> > +	return 0;
> > +}
> > +
> > +static struct acpi_iort_node *
> > +iort_node_map_rid(struct acpi_iort_node *node, u32 rid_in,
> > +		  u32 *rid_out, u8 type)
> > +{
> > +	u32 rid = rid_in;
> > +
> > +	/* Parse the ID mapping tree to find specified node type */
> > +	while (node) {
> > +		struct acpi_iort_id_mapping *map;
> > +		int i;
> > +
> > +		if (node->type == type) {
> > +			if (rid_out)
> > +				*rid_out = rid;
> > +			return node;
> > +		}
> > +
> > +		if (!node->mapping_offset || !node->mapping_count)
> > +			goto fail_map;
> > +
> > +		map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
> > +				   node->mapping_offset);
> > +
> > +		/* Firmware bug! */
> > +		if (!map->output_reference) {
> > +			pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n",
> > +			       node, node->type);
> > +			goto fail_map;
> > +		}
> > +
> > +		/* Do the RID translation */
> > +		for (i = 0; i < node->mapping_count; i++, map++) {
> > +			if (!iort_id_map(map, node->type, rid, &rid))
> > +				break;
> > +		}
> > +
> > +		if (i == node->mapping_count)
> > +			goto fail_map;
> > +
> > +		node = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
> > +				    map->output_reference);
> > +	}
> > +
> > +fail_map:
> > +	/* Map input RID to output RID unchanged on mapping failure*/
> > +	if (rid_out)
> > +		*rid_out = rid_in;
> > +
> > +	return NULL;
> > +}
> > +
> > +static struct acpi_iort_node *
> > +iort_find_dev_node(struct device *dev)
> > +{
> > +	struct pci_bus *pbus;
> > +
> > +	if (!dev_is_pci(dev))
> > +		return iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
> > +				      iort_match_node_callback, dev);
> > +
> > +	/* Find a PCI root bus */
> > +	pbus = to_pci_dev(dev)->bus;
> > +	while (!pci_is_root_bus(pbus))
> > +		pbus = pbus->parent;
> > +
> > +	return iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
> > +			      iort_match_node_callback, &pbus->dev);
> > +}
> > +
> > +void __init iort_table_detect(void)
> > +{
> > +	acpi_status status;
> > +
> > +	status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table);
> > +	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
> > +		const char *msg = acpi_format_exception(status);
> > +		pr_err("Failed to get table, %s\n", msg);
> > +	}
> > +}
> > diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> > index 85b7d07..55a84da 100644
> > --- a/drivers/acpi/bus.c
> > +++ b/drivers/acpi/bus.c
> > @@ -36,6 +36,7 @@
> >  #ifdef CONFIG_X86
> >  #include <asm/mpspec.h>
> >  #endif
> > +#include <linux/iort.h>
> >  #include <linux/pci.h>
> >  #include <acpi/apei.h>
> >  #include <linux/dmi.h>
> > @@ -1186,6 +1187,7 @@ static int __init acpi_init(void)
> >  	}
> >  
> >  	pci_mmcfg_late_init();
> > +	iort_table_detect();
> >  	acpi_scan_init();
> >  	acpi_ec_init();
> >  	acpi_debugfs_init();
> > diff --git a/include/linux/iort.h b/include/linux/iort.h
> > new file mode 100644
> > index 0000000..cde6809
> > --- /dev/null
> > +++ b/include/linux/iort.h
> > @@ -0,0 +1,30 @@
> > +/*
> > + * Copyright (C) 2016, Semihalf
> > + *	Author: Tomasz Nowicki <tn@semihalf.com>
> > + *
> > + * This program is free software; you can redistribute it and/or modify it
> > + * under the terms and conditions of the GNU General Public License,
> > + * version 2, as published by the Free Software Foundation.
> > + *
> > + * This program is distributed in the hope it will be useful, but WITHOUT
> > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> > + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> > + * more details.
> > + *
> > + * You should have received a copy of the GNU General Public License along with
> > + * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
> > + * Place - Suite 330, Boston, MA 02111-1307 USA.
> > + */
> > +
> > +#ifndef __IORT_H__
> > +#define __IORT_H__
> > +
> > +#include <linux/acpi.h>
> > +
> > +#ifdef CONFIG_IORT_TABLE
> > +void iort_table_detect(void);
> > +#else
> > +static inline void iort_table_detect(void) { }
> > +#endif
> > +
> > +#endif /* __IORT_H__ */
> > -- 
> > 1.9.1
> > 
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > 
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Dennis Chen Aug. 19, 2016, 3:39 a.m. UTC | #5 
On Thu, Aug 18, 2016 at 12:14:20PM +0100, Lorenzo Pieralisi wrote:
> On Thu, Aug 18, 2016 at 06:55:50PM +0800, Dennis Chen wrote:
> 
> [...]
> 
> > > +static struct acpi_iort_node *
> > > +iort_scan_node(enum acpi_iort_node_type type,
> > > +	       iort_find_node_callback callback, void *context)
> > > +{
> > > +	struct acpi_iort_node *iort_node, *iort_end;
> > > +	struct acpi_table_iort *iort;
> > > +	int i;
> > > +
> > > +	/* Get the first IORT node */
> > > +	iort = (struct acpi_table_iort *)iort_table;
> > >
> > Here, the same as I comments on Lorenzo's patch. If IORT is missed in
> > the firmware, then iort_table will be NULL, result in kernel panic in
> > the codes followed.
> 
> The pointer is checked in the functions that are visible to
> other compilation units before calling this function:
> 
> iort_msi_map_rid()
> iort_get_device_domain()
> 
> I missed to check it when I added iort_node_match() and
> iort_iommu_configure() though, which makes me think that it is probably
> better to move the iort_table pointer check to iort_scan_node() so that
> it is done in one single place instead of adding it to all given
> external interfaces.
>
Agree to check this in iort_scan_node(). Also, given some duplicate codes between
iort_scan_node() and iort_smmu_init(), so maybe we can think about to refactor
iort_match_callback() as the way to implement the function of iort_smmu_int(),
thus we can call iort_node_match(ACPI_IORT_NODE_SMMU_V3)...

Thanks,
Dennis
> 
> Lorenzo
> 
> > 
> > Thanks,
> > Dennis
> > > +	iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort,
> > > +				 iort->node_offset);
> > > +	iort_end = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
> > > +				iort_table->length);
> > > +
> > > +	for (i = 0; i < iort->node_count; i++) {
> > > +		if (WARN_TAINT(iort_node >= iort_end, TAINT_FIRMWARE_WORKAROUND,
> > > +			       "IORT node pointer overflows, bad table!\n"))
> > > +			return NULL;
> > > +
> > > +		if (iort_node->type == type) {
> > > +			if (ACPI_SUCCESS(callback(iort_node, context)))
> > > +				return iort_node;
> > > +		}
> > > +
> > > +		iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node,
> > > +					 iort_node->length);
> > > +	}
> > > +
> > > +	return NULL;
> > > +}
> > > +
> > > +static acpi_status
> > > +iort_match_node_callback(struct acpi_iort_node *node, void *context)
> > > +{
> > > +	struct device *dev = context;
> > > +
> > > +	switch (node->type) {
> > > +	case ACPI_IORT_NODE_NAMED_COMPONENT: {
> > > +		struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
> > > +		struct acpi_device *adev = to_acpi_device_node(dev->fwnode);
> > > +		struct acpi_iort_named_component *ncomp;
> > > +
> > > +		if (!adev)
> > > +			break;
> > > +
> > > +		ncomp = (struct acpi_iort_named_component *)node->node_data;
> > > +
> > > +		if (ACPI_FAILURE(acpi_get_name(adev->handle,
> > > +					       ACPI_FULL_PATHNAME, &buffer))) {
> > > +			dev_warn(dev, "Can't get device full path name\n");
> > > +		} else {
> > > +			int match;
> > > +
> > > +			match = !strcmp(ncomp->device_name, buffer.pointer);
> > > +			acpi_os_free(buffer.pointer);
> > > +
> > > +			if (match)
> > > +				return AE_OK;
> > > +		}
> > > +
> > > +		break;
> > > +	}
> > > +	case ACPI_IORT_NODE_PCI_ROOT_COMPLEX: {
> > > +		struct acpi_iort_root_complex *pci_rc;
> > > +		struct pci_bus *bus;
> > > +
> > > +		bus = to_pci_bus(dev);
> > > +		pci_rc = (struct acpi_iort_root_complex *)node->node_data;
> > > +
> > > +		/*
> > > +		 * It is assumed that PCI segment numbers maps one-to-one
> > > +		 * with root complexes. Each segment number can represent only
> > > +		 * one root complex.
> > > +		 */
> > > +		if (pci_rc->pci_segment_number == pci_domain_nr(bus))
> > > +			return AE_OK;
> > > +
> > > +		break;
> > > +	}
> > > +	}
> > > +
> > > +	return AE_NOT_FOUND;
> > > +}
> > > +
> > > +static int
> > > +iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in, u32 *rid_out)
> > > +{
> > > +	/* Single mapping does not care for input id */
> > > +	if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
> > > +		if (type == ACPI_IORT_NODE_NAMED_COMPONENT ||
> > > +		    type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
> > > +			*rid_out = map->output_base;
> > > +			return 0;
> > > +		}
> > > +
> > > +		pr_warn(FW_BUG "[map %p] SINGLE MAPPING flag not allowed for node type %d, skipping ID map\n",
> > > +			map, type);
> > > +		return -ENXIO;
> > > +	}
> > > +
> > > +	if (rid_in < map->input_base ||
> > > +	    (rid_in >= map->input_base + map->id_count))
> > > +		return -ENXIO;
> > > +
> > > +	*rid_out = map->output_base + (rid_in - map->input_base);
> > > +	return 0;
> > > +}
> > > +
> > > +static struct acpi_iort_node *
> > > +iort_node_map_rid(struct acpi_iort_node *node, u32 rid_in,
> > > +		  u32 *rid_out, u8 type)
> > > +{
> > > +	u32 rid = rid_in;
> > > +
> > > +	/* Parse the ID mapping tree to find specified node type */
> > > +	while (node) {
> > > +		struct acpi_iort_id_mapping *map;
> > > +		int i;
> > > +
> > > +		if (node->type == type) {
> > > +			if (rid_out)
> > > +				*rid_out = rid;
> > > +			return node;
> > > +		}
> > > +
> > > +		if (!node->mapping_offset || !node->mapping_count)
> > > +			goto fail_map;
> > > +
> > > +		map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
> > > +				   node->mapping_offset);
> > > +
> > > +		/* Firmware bug! */
> > > +		if (!map->output_reference) {
> > > +			pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n",
> > > +			       node, node->type);
> > > +			goto fail_map;
> > > +		}
> > > +
> > > +		/* Do the RID translation */
> > > +		for (i = 0; i < node->mapping_count; i++, map++) {
> > > +			if (!iort_id_map(map, node->type, rid, &rid))
> > > +				break;
> > > +		}
> > > +
> > > +		if (i == node->mapping_count)
> > > +			goto fail_map;
> > > +
> > > +		node = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
> > > +				    map->output_reference);
> > > +	}
> > > +
> > > +fail_map:
> > > +	/* Map input RID to output RID unchanged on mapping failure*/
> > > +	if (rid_out)
> > > +		*rid_out = rid_in;
> > > +
> > > +	return NULL;
> > > +}
> > > +
> > > +static struct acpi_iort_node *
> > > +iort_find_dev_node(struct device *dev)
> > > +{
> > > +	struct pci_bus *pbus;
> > > +
> > > +	if (!dev_is_pci(dev))
> > > +		return iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
> > > +				      iort_match_node_callback, dev);
> > > +
> > > +	/* Find a PCI root bus */
> > > +	pbus = to_pci_dev(dev)->bus;
> > > +	while (!pci_is_root_bus(pbus))
> > > +		pbus = pbus->parent;
> > > +
> > > +	return iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
> > > +			      iort_match_node_callback, &pbus->dev);
> > > +}
> > > +
> > > +void __init iort_table_detect(void)
> > > +{
> > > +	acpi_status status;
> > > +
> > > +	status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table);
> > > +	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
> > > +		const char *msg = acpi_format_exception(status);
> > > +		pr_err("Failed to get table, %s\n", msg);
> > > +	}
> > > +}
> > > diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> > > index 85b7d07..55a84da 100644
> > > --- a/drivers/acpi/bus.c
> > > +++ b/drivers/acpi/bus.c
> > > @@ -36,6 +36,7 @@
> > >  #ifdef CONFIG_X86
> > >  #include <asm/mpspec.h>
> > >  #endif
> > > +#include <linux/iort.h>
> > >  #include <linux/pci.h>
> > >  #include <acpi/apei.h>
> > >  #include <linux/dmi.h>
> > > @@ -1186,6 +1187,7 @@ static int __init acpi_init(void)
> > >  	}
> > >  
> > >  	pci_mmcfg_late_init();
> > > +	iort_table_detect();
> > >  	acpi_scan_init();
> > >  	acpi_ec_init();
> > >  	acpi_debugfs_init();
> > > diff --git a/include/linux/iort.h b/include/linux/iort.h
> > > new file mode 100644
> > > index 0000000..cde6809
> > > --- /dev/null
> > > +++ b/include/linux/iort.h
> > > @@ -0,0 +1,30 @@
> > > +/*
> > > + * Copyright (C) 2016, Semihalf
> > > + *	Author: Tomasz Nowicki <tn@semihalf.com>
> > > + *
> > > + * This program is free software; you can redistribute it and/or modify it
> > > + * under the terms and conditions of the GNU General Public License,
> > > + * version 2, as published by the Free Software Foundation.
> > > + *
> > > + * This program is distributed in the hope it will be useful, but WITHOUT
> > > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> > > + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> > > + * more details.
> > > + *
> > > + * You should have received a copy of the GNU General Public License along with
> > > + * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
> > > + * Place - Suite 330, Boston, MA 02111-1307 USA.
> > > + */
> > > +
> > > +#ifndef __IORT_H__
> > > +#define __IORT_H__
> > > +
> > > +#include <linux/acpi.h>
> > > +
> > > +#ifdef CONFIG_IORT_TABLE
> > > +void iort_table_detect(void);
> > > +#else
> > > +static inline void iort_table_detect(void) { }
> > > +#endif
> > > +
> > > +#endif /* __IORT_H__ */
> > > -- 
> > > 1.9.1
> > > 
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> > > the body of a message to majordomo@vger.kernel.org
> > > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > > 
> 

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Lorenzo Pieralisi Aug. 31, 2016, 9:30 a.m. UTC | #6 
Hi Rafael,

On Thu, Aug 18, 2016 at 08:25:20AM +0200, Tomasz Nowicki wrote:
> On 12.08.2016 18:33, Lorenzo Pieralisi wrote:
> >Hi Tomasz,
> >
> >On Thu, Aug 11, 2016 at 12:06:31PM +0200, Tomasz Nowicki wrote:
> >>IORT shows representation of IO topology for ARM based systems.
> >>It describes how various components are connected together on
> >>parent-child basis e.g. PCI RC -> SMMU -> ITS. Also see IORT spec.
> >>http://infocenter.arm.com/help/topic/com.arm.doc.den0049b/DEN0049B_IO_Remapping_Table.pdf
> >>
> >>Initial support allows to detect IORT table presence and save its
> >>root pointer obtained through acpi_get_table(). The pointer validity
> >>depends on acpi_gbl_permanent_mmap because if acpi_gbl_permanent_mmap
> >>is not set while using IORT nodes we would dereference unmapped pointers.
> >>
> >>For the aforementioned reason call iort_table_detect() from acpi_init()
> >>which guarantees acpi_gbl_permanent_mmap to be set at that point.
> >
> >We still need to get Rafael ACK on this, keeping in mind that the
> >eg code parsing DMAR table relies on the same assumption.
> 
> Exactly.
> 
> Rafael, can you please have a look ?

A gentle reminder, this patch is gating this series and requires
your review, please let us know what you think.

Thank you,
Lorenzo

> 
> >
> >[...]
> >
> >>diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> >>index 445ce28..6cef2d1 100644
> >>--- a/drivers/acpi/Kconfig
> >>+++ b/drivers/acpi/Kconfig
> >>@@ -521,4 +521,9 @@ config ACPI_CONFIGFS
> >> 	  userspace. The configurable ACPI groups will be visible under
> >> 	  /config/acpi, assuming configfs is mounted under /config.
> >>
> >>+if ARM64
> >>+source "drivers/acpi/arm64/Kconfig"
> >>+
> >
> >Just curious: Why do you need a space ?
> 
> No good reason, it will disappear for next version.
> 
> >
> >>+endif
> >>+
> >> endif	# ACPI
> >>diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> >>index 5ae9d85..e5ada78 100644
> >>--- a/drivers/acpi/Makefile
> >>+++ b/drivers/acpi/Makefile
> >>@@ -105,3 +105,5 @@ obj-$(CONFIG_ACPI_CONFIGFS)	+= acpi_configfs.o
> >>
> >> video-objs			+= acpi_video.o video_detect.o
> >> obj-y				+= dptf/
> >>+
> >>+obj-$(CONFIG_ARM64)		+= arm64/
> >>diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
> >>new file mode 100644
> >>index 0000000..fc818dc
> >>--- /dev/null
> >>+++ b/drivers/acpi/arm64/Kconfig
> >>@@ -0,0 +1,6 @@
> >>+#
> >>+# ACPI Configuration for ARM64
> >>+#
> >>+
> >>+config IORT_TABLE
> >>+	bool
> >>diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
> >>new file mode 100644
> >>index 0000000..d01be6f
> >>--- /dev/null
> >>+++ b/drivers/acpi/arm64/Makefile
> >>@@ -0,0 +1 @@
> >>+obj-$(CONFIG_IORT_TABLE) 	+= iort.o
> >>diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> >>new file mode 100644
> >>index 0000000..f89056e
> >>--- /dev/null
> >>+++ b/drivers/acpi/arm64/iort.c
> >>@@ -0,0 +1,218 @@
> >>+/*
> >>+ * Copyright (C) 2016, Semihalf
> >>+ *	Author: Tomasz Nowicki <tn@semihalf.com>
> >>+ *
> >>+ * This program is free software; you can redistribute it and/or modify it
> >>+ * under the terms and conditions of the GNU General Public License,
> >>+ * version 2, as published by the Free Software Foundation.
> >>+ *
> >>+ * This program is distributed in the hope it will be useful, but WITHOUT
> >>+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> >>+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> >>+ * more details.
> >>+ *
> >>+ * This file implements early detection/parsing of I/O mapping
> >>+ * reported to OS through firmware via I/O Remapping Table (IORT)
> >>+ * IORT document number: ARM DEN 0049A
> >>+ */
> >>+
> >>+#define pr_fmt(fmt)	"ACPI: IORT: " fmt
> >>+
> >>+#include <linux/iort.h>
> >>+#include <linux/kernel.h>
> >>+#include <linux/pci.h>
> >>+
> >>+typedef acpi_status (*iort_find_node_callback)
> >>+	(struct acpi_iort_node *node, void *context);
> >>+
> >>+/* Root pointer to the mapped IORT table */
> >>+static struct acpi_table_header *iort_table;
> >
> >See above.
> >
> >[...]
> >
> >>+void __init iort_table_detect(void)
> >>+{
> >>+	acpi_status status;
> >>+
> >>+	status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table);
> >>+	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
> >>+		const char *msg = acpi_format_exception(status);
> >>+		pr_err("Failed to get table, %s\n", msg);
> >>+	}
> >>+}
> >>diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> >>index 85b7d07..55a84da 100644
> >>--- a/drivers/acpi/bus.c
> >>+++ b/drivers/acpi/bus.c
> >>@@ -36,6 +36,7 @@
> >> #ifdef CONFIG_X86
> >> #include <asm/mpspec.h>
> >> #endif
> >>+#include <linux/iort.h>
> >> #include <linux/pci.h>
> >> #include <acpi/apei.h>
> >> #include <linux/dmi.h>
> >>@@ -1186,6 +1187,7 @@ static int __init acpi_init(void)
> >> 	}
> >>
> >> 	pci_mmcfg_late_init();
> >>+	iort_table_detect();
> >
> >That's another bit we have to make sure Rafael is ok with, given
> >that IORT is ARM64 specific (but we stub it out if it is not
> >configured).
> >
> >Having said that:
> >
> >Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> 
> Thanks for your time.
> 
> Tomasz
> 
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fu.wei@linaro.org Sept. 2, 2016, 11:52 a.m. UTC | #7 
Hi Tomasz,

On 11 August 2016 at 18:06, Tomasz Nowicki <tn@semihalf.com> wrote:
> IORT shows representation of IO topology for ARM based systems.
> It describes how various components are connected together on
> parent-child basis e.g. PCI RC -> SMMU -> ITS. Also see IORT spec.
> http://infocenter.arm.com/help/topic/com.arm.doc.den0049b/DEN0049B_IO_Remapping_Table.pdf
>
> Initial support allows to detect IORT table presence and save its
> root pointer obtained through acpi_get_table(). The pointer validity
> depends on acpi_gbl_permanent_mmap because if acpi_gbl_permanent_mmap
> is not set while using IORT nodes we would dereference unmapped pointers.
>
> For the aforementioned reason call iort_table_detect() from acpi_init()
> which guarantees acpi_gbl_permanent_mmap to be set at that point.
>
> Add generic helpers which are helpful for scanning and retrieving
> information from IORT table content. List of the most important helpers:
> - iort_find_dev_node() finds IORT node for a given device
> - iort_node_map_rid() maps device RID and returns IORT node which provides
>   final translation
>
> IORT support is placed under drivers/acpi/arm64/ new directory due to its
> ARM64 specific nature. The code there is considered only for ARM64.
> The long term plan is to keep all ARM64 specific tables support
> in this place e.g. GTDT table.
>
> Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
> ---
>  drivers/acpi/Kconfig        |   5 +
>  drivers/acpi/Makefile       |   2 +
>  drivers/acpi/arm64/Kconfig  |   6 ++
>  drivers/acpi/arm64/Makefile |   1 +
>  drivers/acpi/arm64/iort.c   | 218 ++++++++++++++++++++++++++++++++++++++++++++
>  drivers/acpi/bus.c          |   2 +
>  include/linux/iort.h        |  30 ++++++
>  7 files changed, 264 insertions(+)
>  create mode 100644 drivers/acpi/arm64/Kconfig
>  create mode 100644 drivers/acpi/arm64/Makefile
>  create mode 100644 drivers/acpi/arm64/iort.c
>  create mode 100644 include/linux/iort.h
>
> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> index 445ce28..6cef2d1 100644
> --- a/drivers/acpi/Kconfig
> +++ b/drivers/acpi/Kconfig
> @@ -521,4 +521,9 @@ config ACPI_CONFIGFS
>           userspace. The configurable ACPI groups will be visible under
>           /config/acpi, assuming configfs is mounted under /config.
>
> +if ARM64
> +source "drivers/acpi/arm64/Kconfig"
> +
> +endif
> +
>  endif  # ACPI
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index 5ae9d85..e5ada78 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -105,3 +105,5 @@ obj-$(CONFIG_ACPI_CONFIGFS) += acpi_configfs.o
>
>  video-objs                     += acpi_video.o video_detect.o
>  obj-y                          += dptf/
> +
> +obj-$(CONFIG_ARM64)            += arm64/
> diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
> new file mode 100644
> index 0000000..fc818dc
> --- /dev/null
> +++ b/drivers/acpi/arm64/Kconfig
> @@ -0,0 +1,6 @@
> +#
> +# ACPI Configuration for ARM64
> +#
> +
> +config IORT_TABLE

Sorry for nit-picking, but is that better to use ACPI_IORT
or maybe ARM64__IORT ??

> +       bool
> diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
> new file mode 100644
> index 0000000..d01be6f
> --- /dev/null
> +++ b/drivers/acpi/arm64/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_IORT_TABLE)       += iort.o
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> new file mode 100644
> index 0000000..f89056e
> --- /dev/null
> +++ b/drivers/acpi/arm64/iort.c
> @@ -0,0 +1,218 @@
> +/*
> + * Copyright (C) 2016, Semihalf
> + *     Author: Tomasz Nowicki <tn@semihalf.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * This file implements early detection/parsing of I/O mapping
> + * reported to OS through firmware via I/O Remapping Table (IORT)
> + * IORT document number: ARM DEN 0049A
> + */
> +
> +#define pr_fmt(fmt)    "ACPI: IORT: " fmt
> +
> +#include <linux/iort.h>
> +#include <linux/kernel.h>
> +#include <linux/pci.h>
> +
> +typedef acpi_status (*iort_find_node_callback)
> +       (struct acpi_iort_node *node, void *context);
> +
> +/* Root pointer to the mapped IORT table */
> +static struct acpi_table_header *iort_table;
> +
> +static struct acpi_iort_node *
> +iort_scan_node(enum acpi_iort_node_type type,
> +              iort_find_node_callback callback, void *context)
> +{
> +       struct acpi_iort_node *iort_node, *iort_end;
> +       struct acpi_table_iort *iort;
> +       int i;
> +
> +       /* Get the first IORT node */
> +       iort = (struct acpi_table_iort *)iort_table;
> +       iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort,
> +                                iort->node_offset);
> +       iort_end = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
> +                               iort_table->length);
> +
> +       for (i = 0; i < iort->node_count; i++) {
> +               if (WARN_TAINT(iort_node >= iort_end, TAINT_FIRMWARE_WORKAROUND,
> +                              "IORT node pointer overflows, bad table!\n"))
> +                       return NULL;
> +
> +               if (iort_node->type == type) {
> +                       if (ACPI_SUCCESS(callback(iort_node, context)))
> +                               return iort_node;
> +               }
> +
> +               iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node,
> +                                        iort_node->length);
> +       }
> +
> +       return NULL;
> +}
> +
> +static acpi_status
> +iort_match_node_callback(struct acpi_iort_node *node, void *context)
> +{
> +       struct device *dev = context;
> +
> +       switch (node->type) {
> +       case ACPI_IORT_NODE_NAMED_COMPONENT: {
> +               struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
> +               struct acpi_device *adev = to_acpi_device_node(dev->fwnode);
> +               struct acpi_iort_named_component *ncomp;
> +
> +               if (!adev)
> +                       break;
> +
> +               ncomp = (struct acpi_iort_named_component *)node->node_data;
> +
> +               if (ACPI_FAILURE(acpi_get_name(adev->handle,
> +                                              ACPI_FULL_PATHNAME, &buffer))) {
> +                       dev_warn(dev, "Can't get device full path name\n");
> +               } else {
> +                       int match;
> +
> +                       match = !strcmp(ncomp->device_name, buffer.pointer);
> +                       acpi_os_free(buffer.pointer);
> +
> +                       if (match)
> +                               return AE_OK;
> +               }
> +
> +               break;
> +       }
> +       case ACPI_IORT_NODE_PCI_ROOT_COMPLEX: {
> +               struct acpi_iort_root_complex *pci_rc;
> +               struct pci_bus *bus;
> +
> +               bus = to_pci_bus(dev);
> +               pci_rc = (struct acpi_iort_root_complex *)node->node_data;
> +
> +               /*
> +                * It is assumed that PCI segment numbers maps one-to-one
> +                * with root complexes. Each segment number can represent only
> +                * one root complex.
> +                */
> +               if (pci_rc->pci_segment_number == pci_domain_nr(bus))
> +                       return AE_OK;
> +
> +               break;
> +       }
> +       }
> +
> +       return AE_NOT_FOUND;
> +}
> +
> +static int
> +iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in, u32 *rid_out)
> +{
> +       /* Single mapping does not care for input id */
> +       if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
> +               if (type == ACPI_IORT_NODE_NAMED_COMPONENT ||
> +                   type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
> +                       *rid_out = map->output_base;
> +                       return 0;
> +               }
> +
> +               pr_warn(FW_BUG "[map %p] SINGLE MAPPING flag not allowed for node type %d, skipping ID map\n",
> +                       map, type);
> +               return -ENXIO;
> +       }
> +
> +       if (rid_in < map->input_base ||
> +           (rid_in >= map->input_base + map->id_count))
> +               return -ENXIO;
> +
> +       *rid_out = map->output_base + (rid_in - map->input_base);
> +       return 0;
> +}
> +
> +static struct acpi_iort_node *
> +iort_node_map_rid(struct acpi_iort_node *node, u32 rid_in,
> +                 u32 *rid_out, u8 type)
> +{
> +       u32 rid = rid_in;
> +
> +       /* Parse the ID mapping tree to find specified node type */
> +       while (node) {
> +               struct acpi_iort_id_mapping *map;
> +               int i;
> +
> +               if (node->type == type) {
> +                       if (rid_out)
> +                               *rid_out = rid;
> +                       return node;
> +               }
> +
> +               if (!node->mapping_offset || !node->mapping_count)
> +                       goto fail_map;
> +
> +               map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
> +                                  node->mapping_offset);
> +
> +               /* Firmware bug! */
> +               if (!map->output_reference) {
> +                       pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n",
> +                              node, node->type);
> +                       goto fail_map;
> +               }
> +
> +               /* Do the RID translation */
> +               for (i = 0; i < node->mapping_count; i++, map++) {
> +                       if (!iort_id_map(map, node->type, rid, &rid))
> +                               break;
> +               }
> +
> +               if (i == node->mapping_count)
> +                       goto fail_map;
> +
> +               node = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
> +                                   map->output_reference);
> +       }
> +
> +fail_map:
> +       /* Map input RID to output RID unchanged on mapping failure*/
> +       if (rid_out)
> +               *rid_out = rid_in;
> +
> +       return NULL;
> +}
> +
> +static struct acpi_iort_node *
> +iort_find_dev_node(struct device *dev)
> +{
> +       struct pci_bus *pbus;
> +
> +       if (!dev_is_pci(dev))
> +               return iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
> +                                     iort_match_node_callback, dev);
> +
> +       /* Find a PCI root bus */
> +       pbus = to_pci_dev(dev)->bus;
> +       while (!pci_is_root_bus(pbus))
> +               pbus = pbus->parent;
> +
> +       return iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
> +                             iort_match_node_callback, &pbus->dev);
> +}
> +
> +void __init iort_table_detect(void)
> +{
> +       acpi_status status;
> +
> +       status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table);
> +       if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
> +               const char *msg = acpi_format_exception(status);
> +               pr_err("Failed to get table, %s\n", msg);
> +       }
> +}
> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> index 85b7d07..55a84da 100644
> --- a/drivers/acpi/bus.c
> +++ b/drivers/acpi/bus.c
> @@ -36,6 +36,7 @@
>  #ifdef CONFIG_X86
>  #include <asm/mpspec.h>
>  #endif
> +#include <linux/iort.h>
>  #include <linux/pci.h>
>  #include <acpi/apei.h>
>  #include <linux/dmi.h>
> @@ -1186,6 +1187,7 @@ static int __init acpi_init(void)
>         }
>
>         pci_mmcfg_late_init();
> +       iort_table_detect();
>         acpi_scan_init();
>         acpi_ec_init();
>         acpi_debugfs_init();
> diff --git a/include/linux/iort.h b/include/linux/iort.h
> new file mode 100644
> index 0000000..cde6809
> --- /dev/null
> +++ b/include/linux/iort.h
> @@ -0,0 +1,30 @@
> +/*
> + * Copyright (C) 2016, Semihalf
> + *     Author: Tomasz Nowicki <tn@semihalf.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
> + * Place - Suite 330, Boston, MA 02111-1307 USA.
> + */
> +
> +#ifndef __IORT_H__
> +#define __IORT_H__
> +
> +#include <linux/acpi.h>
> +
> +#ifdef CONFIG_IORT_TABLE
> +void iort_table_detect(void);
> +#else
> +static inline void iort_table_detect(void) { }
> +#endif
> +
> +#endif /* __IORT_H__ */
> --
> 1.9.1
>
> _______________________________________________
> Linaro-acpi mailing list
> Linaro-acpi@lists.linaro.org
> https://lists.linaro.org/mailman/listinfo/linaro-acpi
Tomasz Nowicki Sept. 5, 2016, 6:12 a.m. UTC | #8 
On 02.09.2016 13:52, Fu Wei wrote:
> Hi Tomasz,
>
> On 11 August 2016 at 18:06, Tomasz Nowicki <tn@semihalf.com> wrote:
>> IORT shows representation of IO topology for ARM based systems.
>> It describes how various components are connected together on
>> parent-child basis e.g. PCI RC -> SMMU -> ITS. Also see IORT spec.
>> http://infocenter.arm.com/help/topic/com.arm.doc.den0049b/DEN0049B_IO_Remapping_Table.pdf
>>
>> Initial support allows to detect IORT table presence and save its
>> root pointer obtained through acpi_get_table(). The pointer validity
>> depends on acpi_gbl_permanent_mmap because if acpi_gbl_permanent_mmap
>> is not set while using IORT nodes we would dereference unmapped pointers.
>>
>> For the aforementioned reason call iort_table_detect() from acpi_init()
>> which guarantees acpi_gbl_permanent_mmap to be set at that point.
>>
>> Add generic helpers which are helpful for scanning and retrieving
>> information from IORT table content. List of the most important helpers:
>> - iort_find_dev_node() finds IORT node for a given device
>> - iort_node_map_rid() maps device RID and returns IORT node which provides
>>   final translation
>>
>> IORT support is placed under drivers/acpi/arm64/ new directory due to its
>> ARM64 specific nature. The code there is considered only for ARM64.
>> The long term plan is to keep all ARM64 specific tables support
>> in this place e.g. GTDT table.
>>
>> Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
>> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
>> ---
>>  drivers/acpi/Kconfig        |   5 +
>>  drivers/acpi/Makefile       |   2 +
>>  drivers/acpi/arm64/Kconfig  |   6 ++
>>  drivers/acpi/arm64/Makefile |   1 +
>>  drivers/acpi/arm64/iort.c   | 218 ++++++++++++++++++++++++++++++++++++++++++++
>>  drivers/acpi/bus.c          |   2 +
>>  include/linux/iort.h        |  30 ++++++
>>  7 files changed, 264 insertions(+)
>>  create mode 100644 drivers/acpi/arm64/Kconfig
>>  create mode 100644 drivers/acpi/arm64/Makefile
>>  create mode 100644 drivers/acpi/arm64/iort.c
>>  create mode 100644 include/linux/iort.h
>>
>> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
>> index 445ce28..6cef2d1 100644
>> --- a/drivers/acpi/Kconfig
>> +++ b/drivers/acpi/Kconfig
>> @@ -521,4 +521,9 @@ config ACPI_CONFIGFS
>>           userspace. The configurable ACPI groups will be visible under
>>           /config/acpi, assuming configfs is mounted under /config.
>>
>> +if ARM64
>> +source "drivers/acpi/arm64/Kconfig"
>> +
>> +endif
>> +
>>  endif  # ACPI
>> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
>> index 5ae9d85..e5ada78 100644
>> --- a/drivers/acpi/Makefile
>> +++ b/drivers/acpi/Makefile
>> @@ -105,3 +105,5 @@ obj-$(CONFIG_ACPI_CONFIGFS) += acpi_configfs.o
>>
>>  video-objs                     += acpi_video.o video_detect.o
>>  obj-y                          += dptf/
>> +
>> +obj-$(CONFIG_ARM64)            += arm64/
>> diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
>> new file mode 100644
>> index 0000000..fc818dc
>> --- /dev/null
>> +++ b/drivers/acpi/arm64/Kconfig
>> @@ -0,0 +1,6 @@
>> +#
>> +# ACPI Configuration for ARM64
>> +#
>> +
>> +config IORT_TABLE
>
> Sorry for nit-picking, but is that better to use ACPI_IORT
> or maybe ARM64__IORT ??

ACPI_IORT sounds good.

Tomasz
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fu.wei@linaro.org Sept. 5, 2016, 3:31 p.m. UTC | #9 
Hi Tomasz,

On 5 September 2016 at 14:12, Tomasz Nowicki <tn@semihalf.com> wrote:
> On 02.09.2016 13:52, Fu Wei wrote:
>>
>> Hi Tomasz,
>>
>> On 11 August 2016 at 18:06, Tomasz Nowicki <tn@semihalf.com> wrote:
>>>
>>> IORT shows representation of IO topology for ARM based systems.
>>> It describes how various components are connected together on
>>> parent-child basis e.g. PCI RC -> SMMU -> ITS. Also see IORT spec.
>>>
>>> http://infocenter.arm.com/help/topic/com.arm.doc.den0049b/DEN0049B_IO_Remapping_Table.pdf
>>>
>>> Initial support allows to detect IORT table presence and save its
>>> root pointer obtained through acpi_get_table(). The pointer validity
>>> depends on acpi_gbl_permanent_mmap because if acpi_gbl_permanent_mmap
>>> is not set while using IORT nodes we would dereference unmapped pointers.
>>>
>>> For the aforementioned reason call iort_table_detect() from acpi_init()
>>> which guarantees acpi_gbl_permanent_mmap to be set at that point.
>>>
>>> Add generic helpers which are helpful for scanning and retrieving
>>> information from IORT table content. List of the most important helpers:
>>> - iort_find_dev_node() finds IORT node for a given device
>>> - iort_node_map_rid() maps device RID and returns IORT node which
>>> provides
>>>   final translation
>>>
>>> IORT support is placed under drivers/acpi/arm64/ new directory due to its
>>> ARM64 specific nature. The code there is considered only for ARM64.
>>> The long term plan is to keep all ARM64 specific tables support
>>> in this place e.g. GTDT table.
>>>
>>> Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
>>> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
>>> ---
>>>  drivers/acpi/Kconfig        |   5 +
>>>  drivers/acpi/Makefile       |   2 +
>>>  drivers/acpi/arm64/Kconfig  |   6 ++
>>>  drivers/acpi/arm64/Makefile |   1 +
>>>  drivers/acpi/arm64/iort.c   | 218
>>> ++++++++++++++++++++++++++++++++++++++++++++
>>>  drivers/acpi/bus.c          |   2 +
>>>  include/linux/iort.h        |  30 ++++++
>>>  7 files changed, 264 insertions(+)
>>>  create mode 100644 drivers/acpi/arm64/Kconfig
>>>  create mode 100644 drivers/acpi/arm64/Makefile
>>>  create mode 100644 drivers/acpi/arm64/iort.c
>>>  create mode 100644 include/linux/iort.h
>>>
>>> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
>>> index 445ce28..6cef2d1 100644
>>> --- a/drivers/acpi/Kconfig
>>> +++ b/drivers/acpi/Kconfig
>>> @@ -521,4 +521,9 @@ config ACPI_CONFIGFS
>>>           userspace. The configurable ACPI groups will be visible under
>>>           /config/acpi, assuming configfs is mounted under /config.
>>>
>>> +if ARM64
>>> +source "drivers/acpi/arm64/Kconfig"
>>> +
>>> +endif
>>> +
>>>  endif  # ACPI
>>> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
>>> index 5ae9d85..e5ada78 100644
>>> --- a/drivers/acpi/Makefile
>>> +++ b/drivers/acpi/Makefile
>>> @@ -105,3 +105,5 @@ obj-$(CONFIG_ACPI_CONFIGFS) += acpi_configfs.o
>>>
>>>  video-objs                     += acpi_video.o video_detect.o
>>>  obj-y                          += dptf/
>>> +
>>> +obj-$(CONFIG_ARM64)            += arm64/
>>> diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
>>> new file mode 100644
>>> index 0000000..fc818dc
>>> --- /dev/null
>>> +++ b/drivers/acpi/arm64/Kconfig
>>> @@ -0,0 +1,6 @@
>>> +#
>>> +# ACPI Configuration for ARM64
>>> +#
>>> +
>>> +config IORT_TABLE
>>
>>
>> Sorry for nit-picking, but is that better to use ACPI_IORT
>> or maybe ARM64__IORT ??
>
>
> ACPI_IORT sounds good.

Thanks, Tomasz :-)
I have rebaseed my GTDT patchset on your v8 patchset,
But before I post my new patchset, I  hope we can harmonize with each
other on these:

1. ACPI_IORT --  ACPI_GTDT
2. for the file name,  maybe can follow "/drivers/acpi/acpi_*.c" like
acpi_iort.c and acpi_gtdt.c
or  follow "/drivers/acpi/apei/*.c" like iort.c and gtdt.c.

looking forward to you new patchset :-)
Thanks :-)

>
> Tomasz
diff mbox

Patch

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 445ce28..6cef2d1 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -521,4 +521,9 @@  config ACPI_CONFIGFS
 	  userspace. The configurable ACPI groups will be visible under
 	  /config/acpi, assuming configfs is mounted under /config.
 
+if ARM64
+source "drivers/acpi/arm64/Kconfig"
+
+endif
+
 endif	# ACPI
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 5ae9d85..e5ada78 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -105,3 +105,5 @@  obj-$(CONFIG_ACPI_CONFIGFS)	+= acpi_configfs.o
 
 video-objs			+= acpi_video.o video_detect.o
 obj-y				+= dptf/
+
+obj-$(CONFIG_ARM64)		+= arm64/
diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
new file mode 100644
index 0000000..fc818dc
--- /dev/null
+++ b/drivers/acpi/arm64/Kconfig
@@ -0,0 +1,6 @@ 
+#
+# ACPI Configuration for ARM64
+#
+
+config IORT_TABLE
+	bool
diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
new file mode 100644
index 0000000..d01be6f
--- /dev/null
+++ b/drivers/acpi/arm64/Makefile
@@ -0,0 +1 @@ 
+obj-$(CONFIG_IORT_TABLE) 	+= iort.o
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
new file mode 100644
index 0000000..f89056e
--- /dev/null
+++ b/drivers/acpi/arm64/iort.c
@@ -0,0 +1,218 @@ 
+/*
+ * Copyright (C) 2016, Semihalf
+ *	Author: Tomasz Nowicki <tn@semihalf.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * This file implements early detection/parsing of I/O mapping
+ * reported to OS through firmware via I/O Remapping Table (IORT)
+ * IORT document number: ARM DEN 0049A
+ */
+
+#define pr_fmt(fmt)	"ACPI: IORT: " fmt
+
+#include <linux/iort.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+
+typedef acpi_status (*iort_find_node_callback)
+	(struct acpi_iort_node *node, void *context);
+
+/* Root pointer to the mapped IORT table */
+static struct acpi_table_header *iort_table;
+
+static struct acpi_iort_node *
+iort_scan_node(enum acpi_iort_node_type type,
+	       iort_find_node_callback callback, void *context)
+{
+	struct acpi_iort_node *iort_node, *iort_end;
+	struct acpi_table_iort *iort;
+	int i;
+
+	/* Get the first IORT node */
+	iort = (struct acpi_table_iort *)iort_table;
+	iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort,
+				 iort->node_offset);
+	iort_end = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
+				iort_table->length);
+
+	for (i = 0; i < iort->node_count; i++) {
+		if (WARN_TAINT(iort_node >= iort_end, TAINT_FIRMWARE_WORKAROUND,
+			       "IORT node pointer overflows, bad table!\n"))
+			return NULL;
+
+		if (iort_node->type == type) {
+			if (ACPI_SUCCESS(callback(iort_node, context)))
+				return iort_node;
+		}
+
+		iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node,
+					 iort_node->length);
+	}
+
+	return NULL;
+}
+
+static acpi_status
+iort_match_node_callback(struct acpi_iort_node *node, void *context)
+{
+	struct device *dev = context;
+
+	switch (node->type) {
+	case ACPI_IORT_NODE_NAMED_COMPONENT: {
+		struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+		struct acpi_device *adev = to_acpi_device_node(dev->fwnode);
+		struct acpi_iort_named_component *ncomp;
+
+		if (!adev)
+			break;
+
+		ncomp = (struct acpi_iort_named_component *)node->node_data;
+
+		if (ACPI_FAILURE(acpi_get_name(adev->handle,
+					       ACPI_FULL_PATHNAME, &buffer))) {
+			dev_warn(dev, "Can't get device full path name\n");
+		} else {
+			int match;
+
+			match = !strcmp(ncomp->device_name, buffer.pointer);
+			acpi_os_free(buffer.pointer);
+
+			if (match)
+				return AE_OK;
+		}
+
+		break;
+	}
+	case ACPI_IORT_NODE_PCI_ROOT_COMPLEX: {
+		struct acpi_iort_root_complex *pci_rc;
+		struct pci_bus *bus;
+
+		bus = to_pci_bus(dev);
+		pci_rc = (struct acpi_iort_root_complex *)node->node_data;
+
+		/*
+		 * It is assumed that PCI segment numbers maps one-to-one
+		 * with root complexes. Each segment number can represent only
+		 * one root complex.
+		 */
+		if (pci_rc->pci_segment_number == pci_domain_nr(bus))
+			return AE_OK;
+
+		break;
+	}
+	}
+
+	return AE_NOT_FOUND;
+}
+
+static int
+iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in, u32 *rid_out)
+{
+	/* Single mapping does not care for input id */
+	if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
+		if (type == ACPI_IORT_NODE_NAMED_COMPONENT ||
+		    type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
+			*rid_out = map->output_base;
+			return 0;
+		}
+
+		pr_warn(FW_BUG "[map %p] SINGLE MAPPING flag not allowed for node type %d, skipping ID map\n",
+			map, type);
+		return -ENXIO;
+	}
+
+	if (rid_in < map->input_base ||
+	    (rid_in >= map->input_base + map->id_count))
+		return -ENXIO;
+
+	*rid_out = map->output_base + (rid_in - map->input_base);
+	return 0;
+}
+
+static struct acpi_iort_node *
+iort_node_map_rid(struct acpi_iort_node *node, u32 rid_in,
+		  u32 *rid_out, u8 type)
+{
+	u32 rid = rid_in;
+
+	/* Parse the ID mapping tree to find specified node type */
+	while (node) {
+		struct acpi_iort_id_mapping *map;
+		int i;
+
+		if (node->type == type) {
+			if (rid_out)
+				*rid_out = rid;
+			return node;
+		}
+
+		if (!node->mapping_offset || !node->mapping_count)
+			goto fail_map;
+
+		map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
+				   node->mapping_offset);
+
+		/* Firmware bug! */
+		if (!map->output_reference) {
+			pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n",
+			       node, node->type);
+			goto fail_map;
+		}
+
+		/* Do the RID translation */
+		for (i = 0; i < node->mapping_count; i++, map++) {
+			if (!iort_id_map(map, node->type, rid, &rid))
+				break;
+		}
+
+		if (i == node->mapping_count)
+			goto fail_map;
+
+		node = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
+				    map->output_reference);
+	}
+
+fail_map:
+	/* Map input RID to output RID unchanged on mapping failure*/
+	if (rid_out)
+		*rid_out = rid_in;
+
+	return NULL;
+}
+
+static struct acpi_iort_node *
+iort_find_dev_node(struct device *dev)
+{
+	struct pci_bus *pbus;
+
+	if (!dev_is_pci(dev))
+		return iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
+				      iort_match_node_callback, dev);
+
+	/* Find a PCI root bus */
+	pbus = to_pci_dev(dev)->bus;
+	while (!pci_is_root_bus(pbus))
+		pbus = pbus->parent;
+
+	return iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
+			      iort_match_node_callback, &pbus->dev);
+}
+
+void __init iort_table_detect(void)
+{
+	acpi_status status;
+
+	status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table);
+	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+		const char *msg = acpi_format_exception(status);
+		pr_err("Failed to get table, %s\n", msg);
+	}
+}
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 85b7d07..55a84da 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -36,6 +36,7 @@ 
 #ifdef CONFIG_X86
 #include <asm/mpspec.h>
 #endif
+#include <linux/iort.h>
 #include <linux/pci.h>
 #include <acpi/apei.h>
 #include <linux/dmi.h>
@@ -1186,6 +1187,7 @@  static int __init acpi_init(void)
 	}
 
 	pci_mmcfg_late_init();
+	iort_table_detect();
 	acpi_scan_init();
 	acpi_ec_init();
 	acpi_debugfs_init();
diff --git a/include/linux/iort.h b/include/linux/iort.h
new file mode 100644
index 0000000..cde6809
--- /dev/null
+++ b/include/linux/iort.h
@@ -0,0 +1,30 @@ 
+/*
+ * Copyright (C) 2016, Semihalf
+ *	Author: Tomasz Nowicki <tn@semihalf.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#ifndef __IORT_H__
+#define __IORT_H__
+
+#include <linux/acpi.h>
+
+#ifdef CONFIG_IORT_TABLE
+void iort_table_detect(void);
+#else
+static inline void iort_table_detect(void) { }
+#endif
+
+#endif /* __IORT_H__ */