[1/2,V4] irqchip: gic: Add supports for ARM GICv2m MSI(-X)

Commit Message

Suravee Suthikulpanit Aug. 13, 2014, 3 p.m. UTC

From: Suravee Suthikulpanit <[e-mail]>

ARM GICv2m specification extends GICv2 to support MSI(-X) with
a new set of register frame. This patch introduces support for
the non-secure GICv2m register frame. Currently, GICV2m is available
in certain version of GIC-400.

The patch introduces a new property in ARM gic binding, the v2m subnode.
It is optional.

Signed-off-by: Suravee Suthikulpanit <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Marc Zyngier <[e-mail]>
Cc: Jason Cooper <[e-mail]>
Cc: Catalin Marinas <[e-mail]>
Cc: Will Deacon <[e-mail]>
---
 Documentation/devicetree/bindings/arm/gic.txt |  32 ++++
 drivers/irqchip/Kconfig                       |   7 +
 drivers/irqchip/Makefile                      |   1 +
 drivers/irqchip/irq-gic-v2m.c                 | 215 ++++++++++++++++++++++++++
 drivers/irqchip/irq-gic.c                     |  75 +++++----
 drivers/irqchip/irq-gic.h                     |  48 ++++++
 6 files changed, 348 insertions(+), 30 deletions(-)
 create mode 100644 drivers/irqchip/irq-gic-v2m.c
 create mode 100644 drivers/irqchip/irq-gic.h

Comments

Jingoo Han Aug. 14, 2014, 2:56 a.m. UTC | #1

On Thursday, August 14, 2014 12:01 AM, Suravee Suthikulpanit wrote:
> 
> From: Suravee Suthikulpanit <[e-mail]>
> 
> ARM GICv2m specification extends GICv2 to support MSI(-X) with
> a new set of register frame. This patch introduces support for
> the non-secure GICv2m register frame. Currently, GICV2m is available
> in certain version of GIC-400.
> 
> The patch introduces a new property in ARM gic binding, the v2m subnode.
> It is optional.

Hi Suravee Suthikulpanit,

I added some minor comments.

> 
> Signed-off-by: Suravee Suthikulpanit <[e-mail]>
> Cc: Mark Rutland <[e-mail]>
> Cc: Marc Zyngier <[e-mail]>
> Cc: Jason Cooper <[e-mail]>
> Cc: Catalin Marinas <[e-mail]>
> Cc: Will Deacon <[e-mail]>
> ---
>  Documentation/devicetree/bindings/arm/gic.txt |  32 ++++
>  drivers/irqchip/Kconfig                       |   7 +
>  drivers/irqchip/Makefile                      |   1 +
>  drivers/irqchip/irq-gic-v2m.c                 | 215 ++++++++++++++++++++++++++
>  drivers/irqchip/irq-gic.c                     |  75 +++++----
>  drivers/irqchip/irq-gic.h                     |  48 ++++++
>  6 files changed, 348 insertions(+), 30 deletions(-)
>  create mode 100644 drivers/irqchip/irq-gic-v2m.c
>  create mode 100644 drivers/irqchip/irq-gic.h
> 
> diff --git a/Documentation/devicetree/bindings/arm/gic.txt
> b/Documentation/devicetree/bindings/arm/gic.txt
> index 5573c08..8a64179 100644
> --- a/Documentation/devicetree/bindings/arm/gic.txt
> +++ b/Documentation/devicetree/bindings/arm/gic.txt
> @@ -95,3 +95,35 @@ Example:
>  		      <0x2c006000 0x2000>;
>  		interrupts = <1 9 0xf04>;
>  	};
> +
> +

Please remove the unnecessary line.

> +* GICv2m extension for MSI/MSI-x support (Optional)
> +
> +Certain revision of GIC-400 supports MSI/MSI-x via V2M register frame.
> +This is enabled by specifying v2m sub-node.
> +
> +Required properties:
> +
> +- msi-controller : Identifies the node as an MSI controller.
> +
> +- reg : GICv2m MSI interface register base and size
> +
> +Example:
> +
> +	interrupt-controller@e1101000 {
> +		compatible = "arm,gic-400";
> +		#interrupt-cells = <3>;
> +		#address-cells = <2>;
> +		#size-cells = <2>;
> +		interrupt-controller;
> +		interrupts = <1 8 0xf04>;
> +		ranges = <0 0 0 0xe1100000 0 0x100000>;
> +		reg = <0x0 0xe1110000 0 0x01000>,
> +		      <0x0 0xe112f000 0 0x02000>,
> +		      <0x0 0xe1140000 0 0x10000>,
> +		      <0x0 0xe1160000 0 0x10000>;
> +		v2m {
> +			msi-controller;
> +			reg = <0x0 0x80000 0 0x1000>;
> +		};
> +	};
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index 4e230e7..9aa5edc 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -7,6 +7,13 @@ config ARM_GIC
>  	select IRQ_DOMAIN
>  	select MULTI_IRQ_HANDLER
> 
> +config ARM_GIC_V2M
> +	bool
> +	select IRQ_DOMAIN
> +	select MULTI_IRQ_HANDLER
> +	depends on ARM_GIC
> +	depends on PCI && PCI_MSI
> +
>  config GIC_NON_BANKED
>  	bool
> 
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index 73052ba..3bda951 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -17,6 +17,7 @@ obj-$(CONFIG_ARCH_SUNXI)		+= irq-sun4i.o
>  obj-$(CONFIG_ARCH_SUNXI)		+= irq-sunxi-nmi.o
>  obj-$(CONFIG_ARCH_SPEAR3XX)		+= spear-shirq.o
>  obj-$(CONFIG_ARM_GIC)			+= irq-gic.o irq-gic-common.o
> +obj-$(CONFIG_ARM_GIC_V2M)		+= irq-gic-v2m.o
>  obj-$(CONFIG_ARM_GIC_V3)		+= irq-gic-v3.o irq-gic-common.o
>  obj-$(CONFIG_ARM_NVIC)			+= irq-nvic.o
>  obj-$(CONFIG_ARM_VIC)			+= irq-vic.o
> diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c
> new file mode 100644
> index 0000000..1ac0ace
> --- /dev/null
> +++ b/drivers/irqchip/irq-gic-v2m.c
> @@ -0,0 +1,215 @@
> +/*
> + * ARM GIC v2m MSI(-X) support
> + * Support for Message Signalelled Interrupts for systems that

s/Signalelled/Signaled

> + * implement ARM Generic Interrupt Controller: GICv2m.
> + *
> + * Copyright (C) 2014 Advanced Micro Devices, Inc.
> + * Authors: Suravee Suthikulpanit <[e-mail]>
> + *          Harish Kasiviswanathan <[e-mail]>
> + *          Brandon Anderson <[e-mail]>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published
> + * by the Free Software Foundation.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/pci.h>
> +#include <linux/irq.h>
> +#include <linux/spinlock.h>
> +#include <linux/slab.h>
> +#include <linux/of_address.h>
> +#include <linux/of_pci.h>
> +#include <linux/bitmap.h>

Please, re-order these headers alphabetically.
It enhances the readability.

> +
> +#include "irqchip.h"
> +#include "irq-gic.h"
> +
> +/*
> +* MSI_TYPER:
> +*     [31:26] Reserved
> +*     [25:16] lowest SPI assigned to MSI
> +*     [15:10] Reserved
> +*     [9:0]   Numer of SPIs assigned to MSI
> +*/
> +#define V2M_MSI_TYPER			0x008
> +#define V2M_MSI_TYPER_BASE_SHIFT	(16)
> +#define V2M_MSI_TYPER_BASE_MASK		(0x3FF)
> +#define V2M_MSI_TYPER_NUM_MASK		(0x3FF)

These braces are unnecessary.
Please remove them as follows.

+#define V2M_MSI_TYPER_BASE_SHIFT	16
+#define V2M_MSI_TYPER_BASE_MASK		0x3FF
+#define V2M_MSI_TYPER_NUM_MASK		0x3FF

> +#define V2M_MSI_SETSPI_NS		0x040
> +#define V2M_MIN_SPI			32
> +#define V2M_MAX_SPI			1019
> +
> +/*
> + * alloc_msi_irq - Allocate MSIs from avaialbe MSI bitmap.

s/avaialbe/available

> + * @data: Pointer to v2m_data
> + * @nvec: Number of interrupts to allocate
> + * @irq: Pointer to the allocated irq
> + *
> + * Allocates interrupts only if the contiguous range of MSIs
> + * with specified nvec are available. Otherwise return the number
> + * of available interrupts. If none are available, then returns -ENOENT.
> + */
> +static int alloc_msi_irq(struct v2m_data *data, int nvec, int *irq)
> +{
> +	int size = data->nr_spis;
> +	int next = size, i = nvec, ret;
> +
> +	/* We should never allocate more than available nr_spis */
> +	if (i >= size)
> +		i = size;
> +
> +	spin_lock(&data->msi_cnt_lock);
> +
> +	for (; i > 0; i--) {
> +		next = bitmap_find_next_zero_area(data->bm,
> +					size, 0, i, 0);
> +		if (next < size)
> +			break;
> +	}
> +
> +	if (i != nvec) {
> +		ret = i ? : -ENOENT;
> +	} else {
> +		bitmap_set(data->bm, next, nvec);
> +		*irq = data->spi_start + next;
> +		ret = 0;
> +	}
> +
> +	spin_unlock(&data->msi_cnt_lock);
> +
> +	return ret;
> +}
> +
> +static void gicv2m_teardown_msi_irq(struct msi_chip *chip, unsigned int irq)
> +{
> +	int pos;
> +	struct v2m_data *data = container_of(chip, struct v2m_data, msi_chip);
> +
> +	spin_lock(&data->msi_cnt_lock);
> +
> +	pos = irq - data->spi_start;
> +	if (pos >= 0 && pos < data->nr_spis)
> +		bitmap_clear(data->bm, pos, 1);
> +
> +	spin_unlock(&data->msi_cnt_lock);
> +}
> +
> +static int gicv2m_setup_msi_irq(struct msi_chip *chip, struct pci_dev *pdev,
> +		      struct msi_desc *desc)
> +{
> +	int avail, irq = 0;
> +	struct msi_msg msg;
> +	phys_addr_t addr;
> +	struct v2m_data *data = container_of(chip, struct v2m_data, msi_chip);
> +
> +	if (!desc) {
> +		dev_err(&pdev->dev,
> +			"GICv2m: MSI setup failed. Invalid msi descriptor\n");
> +		return -EINVAL;
> +	}
> +
> +	avail = alloc_msi_irq(data, 1, &irq);
> +	if (avail != 0) {
> +		dev_err(&pdev->dev,
> +			"GICv2m: MSI setup failed. Cannnot allocate IRQ\n");
> +		return -ENOSPC;
> +	}
> +
> +	irq_set_chip_data(irq, chip);
> +	irq_set_msi_desc(irq, desc);
> +	irq_set_irq_type(irq, IRQ_TYPE_EDGE_RISING);
> +
> +	addr = data->res.start + V2M_MSI_SETSPI_NS;
> +
> +	msg.address_hi = (u32)(addr >> 32);
> +	msg.address_lo = (u32)(addr);
> +	msg.data = irq;
> +	write_msi_msg(irq, &msg);
> +
> +	return 0;
> +}
> +
> +static void gicv2m_mask_irq(struct irq_data *d)
> +{
> +	gic_mask_irq(d);
> +	if (d->msi_desc)
> +		mask_msi_irq(d);
> +}
> +
> +static void gicv2m_unmask_irq(struct irq_data *d)
> +{
> +	gic_unmask_irq(d);
> +	if (d->msi_desc)
> +		unmask_msi_irq(d);
> +}
> +
> +static struct irq_chip gicv2m_chip;
> +
> +#ifdef CONFIG_OF
> +int __init
> +gicv2m_of_init(struct device_node *node, struct gic_chip_data *gic)
> +{
> +	int ret;
> +	unsigned int val;
> +	struct v2m_data *v2m = &gic->v2m_data;
> +
> +	v2m->msi_chip.owner = THIS_MODULE;
> +	v2m->msi_chip.of_node = node;
> +	v2m->msi_chip.setup_irq = gicv2m_setup_msi_irq;
> +	v2m->msi_chip.teardown_irq = gicv2m_teardown_msi_irq;
> +	ret = of_pci_msi_chip_add(&v2m->msi_chip);
> +	if (ret) {
> +		pr_info("GICv2m: Failed to add msi_chip.\n");

You don't need to add "GICv2m:" to all pr_*() functions.
Instead, you can add the following one at the top of the this .c file.

#define pr_fmt(fmt) " GICv2m: " fmt


> +		return ret;
> +	}
> +
> +	if (of_address_to_resource(node, 0, &v2m->res)) {
> +		pr_err("GICv2m: Failed locate GICv2m MSI register frame\n");
> +		return -EINVAL;
> +	}
> +
> +	v2m->base = of_iomap(node, 0);
> +	if (!v2m->base) {
> +		pr_err("GICv2m: Failed to map GIC MSI registers\n");
> +		return -EINVAL;
> +	}
> +
> +	val = readl_relaxed(v2m->base + V2M_MSI_TYPER);
> +	if (!val) {
> +		pr_warn("GICv2m: Failed to read V2M_MSI_TYPER register\n");
> +		return -EINVAL;
> +	}
> +
> +	v2m->spi_start = (val >> V2M_MSI_TYPER_BASE_SHIFT) &
> +				V2M_MSI_TYPER_BASE_MASK;
> +	v2m->nr_spis = val & V2M_MSI_TYPER_NUM_MASK;
> +	if ((v2m->spi_start < V2M_MIN_SPI) || (v2m->nr_spis >= V2M_MAX_SPI)) {
> +			pr_err("GICv2m: Invalid MSI_TYPER (%#x)\n", val);
> +			return -EINVAL;
> +	}
> +
> +	v2m->bm = kzalloc(sizeof(long) * BITS_TO_LONGS(v2m->nr_spis),
> +			  GFP_KERNEL);
> +	if (!v2m->bm) {
> +		pr_err("GICv2m: Failed to allocate MSI bitmap\n");
> +		return -ENOMEM;
> +	}
> +
> +	spin_lock_init(&v2m->msi_cnt_lock);
> +
> +	pr_info("GICv2m: SPI range [%d:%d]\n",
> +		v2m->spi_start, (v2m->spi_start + v2m->nr_spis));
> +
> +	memcpy(&gicv2m_chip, gic->irq_chip, sizeof(struct irq_chip));
> +	gicv2m_chip.name = "GICv2m",
> +	gicv2m_chip.irq_mask = gicv2m_mask_irq;
> +	gicv2m_chip.irq_unmask = gicv2m_unmask_irq;
> +	gic->irq_chip = &gicv2m_chip;
> +
> +	return 0;
> +}
> +
> +#endif /* CONFIG_OF */

[.....]

Best regards,
Jingoo Han


--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to [e-mail]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Mark Rutland Aug. 14, 2014, 5:55 p.m. UTC | #2

On Wed, Aug 13, 2014 at 04:00:40PM +0100, [e-mail] wrote:
> From: Suravee Suthikulpanit <[e-mail]>
> 
> ARM GICv2m specification extends GICv2 to support MSI(-X) with
> a new set of register frame. This patch introduces support for
> the non-secure GICv2m register frame. Currently, GICV2m is available
> in certain version of GIC-400.
> 
> The patch introduces a new property in ARM gic binding, the v2m subnode.
> It is optional.
> 
> Signed-off-by: Suravee Suthikulpanit <[e-mail]>
> Cc: Mark Rutland <[e-mail]>
> Cc: Marc Zyngier <[e-mail]>
> Cc: Jason Cooper <[e-mail]>
> Cc: Catalin Marinas <[e-mail]>
> Cc: Will Deacon <[e-mail]>
> ---
>  Documentation/devicetree/bindings/arm/gic.txt |  32 ++++
>  drivers/irqchip/Kconfig                       |   7 +
>  drivers/irqchip/Makefile                      |   1 +
>  drivers/irqchip/irq-gic-v2m.c                 | 215 ++++++++++++++++++++++++++
>  drivers/irqchip/irq-gic.c                     |  75 +++++----
>  drivers/irqchip/irq-gic.h                     |  48 ++++++
>  6 files changed, 348 insertions(+), 30 deletions(-)
>  create mode 100644 drivers/irqchip/irq-gic-v2m.c
>  create mode 100644 drivers/irqchip/irq-gic.h
> 
> diff --git a/Documentation/devicetree/bindings/arm/gic.txt b/Documentation/devicetree/bindings/arm/gic.txt
> index 5573c08..8a64179 100644
> --- a/Documentation/devicetree/bindings/arm/gic.txt
> +++ b/Documentation/devicetree/bindings/arm/gic.txt
> @@ -95,3 +95,35 @@ Example:
>                       <0x2c006000 0x2000>;
>                 interrupts = <1 9 0xf04>;
>         };
> +
> +
> +* GICv2m extension for MSI/MSI-x support (Optional)
> +
> +Certain revision of GIC-400 supports MSI/MSI-x via V2M register frame.
> +This is enabled by specifying v2m sub-node.
> +
> +Required properties:
> +
> +- msi-controller : Identifies the node as an MSI controller.
> +
> +- reg : GICv2m MSI interface register base and size
> +
> +Example:
> +
> +       interrupt-controller@e1101000 {
> +               compatible = "arm,gic-400";
> +               #interrupt-cells = <3>;
> +               #address-cells = <2>;
> +               #size-cells = <2>;
> +               interrupt-controller;
> +               interrupts = <1 8 0xf04>;
> +               ranges = <0 0 0 0xe1100000 0 0x100000>;
> +               reg = <0x0 0xe1110000 0 0x01000>,
> +                     <0x0 0xe112f000 0 0x02000>,
> +                     <0x0 0xe1140000 0 0x10000>,
> +                     <0x0 0xe1160000 0 0x10000>;
> +               v2m {
> +                       msi-controller;
> +                       reg = <0x0 0x80000 0 0x1000>;
> +               };
> +       };

[...]

> @@ -1009,6 +1012,16 @@ gic_of_init(struct device_node *node, struct device_node *parent)
>         if (of_property_read_u32(node, "cpu-offset", &percpu_offset))
>                 percpu_offset = 0;
> 
> +       gic_data[gic_cnt].irq_chip = &gic_chip;
> +
> +       /* Currently, we only support one v2m subnode. */
> +       child = of_get_child_by_name(node, "v2m");
> +       if (child) {
> +               ret = gicv2m_of_init(child, &gic_data[gic_cnt]);
> +               if (ret)
> +                       return ret;
> +       }

I can't see how you'd sanely expand this to multiple children, which was
the main point of having a separate node for the M block.

Give the M block a compatible string and look for children with that
string.

Thanks,
Mark.
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to [e-mail]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Marc Zyngier Aug. 15, 2014, 2:03 p.m. UTC | #3

Hi Suravee,

On Wed, Aug 13 2014 at  4:00:40 pm BST, "[e-mail]" <[e-mail]> wrote:
> From: Suravee Suthikulpanit <[e-mail]>
>
> ARM GICv2m specification extends GICv2 to support MSI(-X) with
> a new set of register frame. This patch introduces support for
> the non-secure GICv2m register frame. Currently, GICV2m is available
> in certain version of GIC-400.
>
> The patch introduces a new property in ARM gic binding, the v2m subnode.
> It is optional.

This is starting to look better. See below my comments.

> Signed-off-by: Suravee Suthikulpanit <[e-mail]>
> Cc: Mark Rutland <[e-mail]>
> Cc: Marc Zyngier <[e-mail]>
> Cc: Jason Cooper <[e-mail]>
> Cc: Catalin Marinas <[e-mail]>
> Cc: Will Deacon <[e-mail]>
> ---
>  Documentation/devicetree/bindings/arm/gic.txt |  32 ++++
>  drivers/irqchip/Kconfig                       |   7 +
>  drivers/irqchip/Makefile                      |   1 +
>  drivers/irqchip/irq-gic-v2m.c                 | 215 ++++++++++++++++++++++++++
>  drivers/irqchip/irq-gic.c                     |  75 +++++----
>  drivers/irqchip/irq-gic.h                     |  48 ++++++
>  6 files changed, 348 insertions(+), 30 deletions(-)
>  create mode 100644 drivers/irqchip/irq-gic-v2m.c
>  create mode 100644 drivers/irqchip/irq-gic.h
>
> diff --git a/Documentation/devicetree/bindings/arm/gic.txt b/Documentation/devicetree/bindings/arm/gic.txt
> index 5573c08..8a64179 100644
> --- a/Documentation/devicetree/bindings/arm/gic.txt
> +++ b/Documentation/devicetree/bindings/arm/gic.txt
> @@ -95,3 +95,35 @@ Example:
>                       <0x2c006000 0x2000>;
>                 interrupts = <1 9 0xf04>;
>         };
> +
> +
> +* GICv2m extension for MSI/MSI-x support (Optional)
> +
> +Certain revision of GIC-400 supports MSI/MSI-x via V2M register frame.
> +This is enabled by specifying v2m sub-node.
> +
> +Required properties:
> +
> +- msi-controller : Identifies the node as an MSI controller.
> +
> +- reg : GICv2m MSI interface register base and size
> +
> +Example:
> +
> +       interrupt-controller@e1101000 {
> +               compatible = "arm,gic-400";
> +               #interrupt-cells = <3>;
> +               #address-cells = <2>;
> +               #size-cells = <2>;
> +               interrupt-controller;
> +               interrupts = <1 8 0xf04>;
> +               ranges = <0 0 0 0xe1100000 0 0x100000>;
> +               reg = <0x0 0xe1110000 0 0x01000>,
> +                     <0x0 0xe112f000 0 0x02000>,
> +                     <0x0 0xe1140000 0 0x10000>,
> +                     <0x0 0xe1160000 0 0x10000>;
> +               v2m {
> +                       msi-controller;
> +                       reg = <0x0 0x80000 0 0x1000>;
> +               };
> +       };
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index 4e230e7..9aa5edc 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -7,6 +7,13 @@ config ARM_GIC
>         select IRQ_DOMAIN
>         select MULTI_IRQ_HANDLER
>
> +config ARM_GIC_V2M
> +       bool
> +       select IRQ_DOMAIN
> +       select MULTI_IRQ_HANDLER
> +       depends on ARM_GIC
> +       depends on PCI && PCI_MSI
> +
>  config GIC_NON_BANKED
>         bool
>
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index 73052ba..3bda951 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -17,6 +17,7 @@ obj-$(CONFIG_ARCH_SUNXI)              += irq-sun4i.o
>  obj-$(CONFIG_ARCH_SUNXI)               += irq-sunxi-nmi.o
>  obj-$(CONFIG_ARCH_SPEAR3XX)            += spear-shirq.o
>  obj-$(CONFIG_ARM_GIC)                  += irq-gic.o irq-gic-common.o
> +obj-$(CONFIG_ARM_GIC_V2M)              += irq-gic-v2m.o
>  obj-$(CONFIG_ARM_GIC_V3)               += irq-gic-v3.o irq-gic-common.o
>  obj-$(CONFIG_ARM_NVIC)                 += irq-nvic.o
>  obj-$(CONFIG_ARM_VIC)                  += irq-vic.o
> diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c
> new file mode 100644
> index 0000000..1ac0ace
> --- /dev/null
> +++ b/drivers/irqchip/irq-gic-v2m.c
> @@ -0,0 +1,215 @@
> +/*
> + * ARM GIC v2m MSI(-X) support
> + * Support for Message Signalelled Interrupts for systems that
> + * implement ARM Generic Interrupt Controller: GICv2m.
> + *
> + * Copyright (C) 2014 Advanced Micro Devices, Inc.
> + * Authors: Suravee Suthikulpanit <[e-mail]>
> + *          Harish Kasiviswanathan <[e-mail]>
> + *          Brandon Anderson <[e-mail]>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published
> + * by the Free Software Foundation.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/pci.h>
> +#include <linux/irq.h>
> +#include <linux/spinlock.h>
> +#include <linux/slab.h>
> +#include <linux/of_address.h>
> +#include <linux/of_pci.h>
> +#include <linux/bitmap.h>
> +
> +#include "irqchip.h"
> +#include "irq-gic.h"
> +
> +/*
> +* MSI_TYPER:
> +*     [31:26] Reserved
> +*     [25:16] lowest SPI assigned to MSI
> +*     [15:10] Reserved
> +*     [9:0]   Numer of SPIs assigned to MSI
> +*/
> +#define V2M_MSI_TYPER                  0x008
> +#define V2M_MSI_TYPER_BASE_SHIFT       (16)
> +#define V2M_MSI_TYPER_BASE_MASK                (0x3FF)
> +#define V2M_MSI_TYPER_NUM_MASK         (0x3FF)
> +#define V2M_MSI_SETSPI_NS              0x040
> +#define V2M_MIN_SPI                    32
> +#define V2M_MAX_SPI                    1019
> +
> +/*
> + * alloc_msi_irq - Allocate MSIs from avaialbe MSI bitmap.
> + * @data: Pointer to v2m_data
> + * @nvec: Number of interrupts to allocate
> + * @irq: Pointer to the allocated irq
> + *
> + * Allocates interrupts only if the contiguous range of MSIs
> + * with specified nvec are available. Otherwise return the number
> + * of available interrupts. If none are available, then returns -ENOENT.
> + */
> +static int alloc_msi_irq(struct v2m_data *data, int nvec, int *irq)
> +{
> +       int size = data->nr_spis;
> +       int next = size, i = nvec, ret;
> +
> +       /* We should never allocate more than available nr_spis */
> +       if (i >= size)
> +               i = size;
> +
> +       spin_lock(&data->msi_cnt_lock);
> +
> +       for (; i > 0; i--) {
> +               next = bitmap_find_next_zero_area(data->bm,
> +                                       size, 0, i, 0);
> +               if (next < size)
> +                       break;
> +       }
> +
> +       if (i != nvec) {
> +               ret = i ? : -ENOENT;
> +       } else {
> +               bitmap_set(data->bm, next, nvec);
> +               *irq = data->spi_start + next;
> +               ret = 0;
> +       }
> +
> +       spin_unlock(&data->msi_cnt_lock);
> +
> +       return ret;
> +}
> +
> +static void gicv2m_teardown_msi_irq(struct msi_chip *chip, unsigned int irq)
> +{
> +       int pos;
> +       struct v2m_data *data = container_of(chip, struct v2m_data, msi_chip);
> +
> +       spin_lock(&data->msi_cnt_lock);
> +
> +       pos = irq - data->spi_start;
> +       if (pos >= 0 && pos < data->nr_spis)
> +               bitmap_clear(data->bm, pos, 1);
> +
> +       spin_unlock(&data->msi_cnt_lock);
> +}
> +
> +static int gicv2m_setup_msi_irq(struct msi_chip *chip, struct pci_dev *pdev,
> +                     struct msi_desc *desc)
> +{
> +       int avail, irq = 0;
> +       struct msi_msg msg;
> +       phys_addr_t addr;
> +       struct v2m_data *data = container_of(chip, struct v2m_data, msi_chip);
> +
> +       if (!desc) {
> +               dev_err(&pdev->dev,
> +                       "GICv2m: MSI setup failed. Invalid msi descriptor\n");
> +               return -EINVAL;
> +       }
> +
> +       avail = alloc_msi_irq(data, 1, &irq);
> +       if (avail != 0) {
> +               dev_err(&pdev->dev,
> +                       "GICv2m: MSI setup failed. Cannnot allocate IRQ\n");
> +               return -ENOSPC;
> +       }
> +
> +       irq_set_chip_data(irq, chip);
> +       irq_set_msi_desc(irq, desc);
> +       irq_set_irq_type(irq, IRQ_TYPE_EDGE_RISING);
> +
> +       addr = data->res.start + V2M_MSI_SETSPI_NS;
> +
> +       msg.address_hi = (u32)(addr >> 32);
> +       msg.address_lo = (u32)(addr);
> +       msg.data = irq;
> +       write_msi_msg(irq, &msg);
> +
> +       return 0;
> +}
> +
> +static void gicv2m_mask_irq(struct irq_data *d)
> +{
> +       gic_mask_irq(d);
> +       if (d->msi_desc)
> +               mask_msi_irq(d);
> +}
> +
> +static void gicv2m_unmask_irq(struct irq_data *d)
> +{
> +       gic_unmask_irq(d);
> +       if (d->msi_desc)
> +               unmask_msi_irq(d);
> +}
> +
> +static struct irq_chip gicv2m_chip;
> +
> +#ifdef CONFIG_OF

Is there any reason why this should be guarded by CONFIG_OF? Surely the
v2m capability should only be enabled if OF is.

> +int __init
> +gicv2m_of_init(struct device_node *node, struct gic_chip_data *gic)
> +{
> +       int ret;
> +       unsigned int val;
> +       struct v2m_data *v2m = &gic->v2m_data;
> +
> +       v2m->msi_chip.owner = THIS_MODULE;
> +       v2m->msi_chip.of_node = node;
> +       v2m->msi_chip.setup_irq = gicv2m_setup_msi_irq;
> +       v2m->msi_chip.teardown_irq = gicv2m_teardown_msi_irq;
> +       ret = of_pci_msi_chip_add(&v2m->msi_chip);
> +       if (ret) {
> +               pr_info("GICv2m: Failed to add msi_chip.\n");
> +               return ret;
> +       }
> +
> +       if (of_address_to_resource(node, 0, &v2m->res)) {
> +               pr_err("GICv2m: Failed locate GICv2m MSI register frame\n");
> +               return -EINVAL;
> +       }
> +
> +       v2m->base = of_iomap(node, 0);
> +       if (!v2m->base) {
> +               pr_err("GICv2m: Failed to map GIC MSI registers\n");
> +               return -EINVAL;
> +       }
> +
> +       val = readl_relaxed(v2m->base + V2M_MSI_TYPER);
> +       if (!val) {
> +               pr_warn("GICv2m: Failed to read V2M_MSI_TYPER register\n");
> +               return -EINVAL;
> +       }
> +
> +       v2m->spi_start = (val >> V2M_MSI_TYPER_BASE_SHIFT) &
> +                               V2M_MSI_TYPER_BASE_MASK;
> +       v2m->nr_spis = val & V2M_MSI_TYPER_NUM_MASK;
> +       if ((v2m->spi_start < V2M_MIN_SPI) || (v2m->nr_spis >= V2M_MAX_SPI)) {
> +                       pr_err("GICv2m: Invalid MSI_TYPER (%#x)\n", val);
> +                       return -EINVAL;
> +       }
> +
> +       v2m->bm = kzalloc(sizeof(long) * BITS_TO_LONGS(v2m->nr_spis),
> +                         GFP_KERNEL);
> +       if (!v2m->bm) {
> +               pr_err("GICv2m: Failed to allocate MSI bitmap\n");
> +               return -ENOMEM;
> +       }
> +
> +       spin_lock_init(&v2m->msi_cnt_lock);
> +
> +       pr_info("GICv2m: SPI range [%d:%d]\n",
> +               v2m->spi_start, (v2m->spi_start + v2m->nr_spis));
> +
> +       memcpy(&gicv2m_chip, gic->irq_chip, sizeof(struct irq_chip));
> +       gicv2m_chip.name = "GICv2m",
> +       gicv2m_chip.irq_mask = gicv2m_mask_irq;
> +       gicv2m_chip.irq_unmask = gicv2m_unmask_irq;
> +       gic->irq_chip = &gicv2m_chip;

I liked it until this last line. You're overriding the irq_chip for the
whole GIC. I was expecting you'd only use it for the MSI range
(basically return a range to the caller, together with your brand new
irq_chip).

> +
> +       return 0;
> +}
> +
> +#endif /* CONFIG_OF */
> diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
> index 508b815..b175ccf 100644
> --- a/drivers/irqchip/irq-gic.c
> +++ b/drivers/irqchip/irq-gic.c
> @@ -47,30 +47,9 @@
>  #include <asm/smp_plat.h>
>
>  #include "irq-gic-common.h"
> +#include "irq-gic.h"
>  #include "irqchip.h"
>
> -union gic_base {
> -       void __iomem *common_base;
> -       void __percpu * __iomem *percpu_base;
> -};
> -
> -struct gic_chip_data {
> -       union gic_base dist_base;
> -       union gic_base cpu_base;
> -#ifdef CONFIG_CPU_PM
> -       u32 saved_spi_enable[DIV_ROUND_UP(1020, 32)];
> -       u32 saved_spi_conf[DIV_ROUND_UP(1020, 16)];
> -       u32 saved_spi_target[DIV_ROUND_UP(1020, 4)];
> -       u32 __percpu *saved_ppi_enable;
> -       u32 __percpu *saved_ppi_conf;
> -#endif
> -       struct irq_domain *domain;
> -       unsigned int gic_irqs;
> -#ifdef CONFIG_GIC_NON_BANKED
> -       void __iomem *(*get_base)(union gic_base *);
> -#endif
> -};
> -
>  static DEFINE_RAW_SPINLOCK(irq_controller_lock);
>
>  /*
> @@ -132,15 +111,36 @@ static inline void gic_set_base_accessor(struct gic_chip_data *data,
>  #define gic_set_base_accessor(d, f)
>  #endif
>
> +static inline
> +struct gic_chip_data *irq_data_get_gic_chip_data(struct irq_data *d)
> +{
> +       struct gic_chip_data *gic_data;
> +       struct msi_chip *mchip;
> +       struct v2m_data *v2mdat;
> +
> +       /*
> +        * For MSI, irq_data.chip_data points to struct msi_chip.
> +        * For non-MSI, irq_data.chip_data points to struct gic_chip_data.
> +        */
> +       if (d->msi_desc) {
> +               mchip = irq_data_get_irq_chip_data(d);
> +               v2mdat = container_of(mchip, struct v2m_data, msi_chip);
> +               gic_data = container_of(v2mdat, struct gic_chip_data, v2m_data);
> +       } else {
> +               gic_data = irq_data_get_irq_chip_data(d);
> +       }
> +       return gic_data;
> +}
> +
>  static inline void __iomem *gic_dist_base(struct irq_data *d)
>  {
> -       struct gic_chip_data *gic_data = irq_data_get_irq_chip_data(d);
> +       struct gic_chip_data *gic_data = irq_data_get_gic_chip_data(d);
>         return gic_data_dist_base(gic_data);
>  }
>
>  static inline void __iomem *gic_cpu_base(struct irq_data *d)
>  {
> -       struct gic_chip_data *gic_data = irq_data_get_irq_chip_data(d);
> +       struct gic_chip_data *gic_data = irq_data_get_gic_chip_data(d);
>         return gic_data_cpu_base(gic_data);
>  }
>
> @@ -152,7 +152,7 @@ static inline unsigned int gic_irq(struct irq_data *d)
>  /*
>   * Routines to acknowledge, disable and enable interrupts
>   */
> -static void gic_mask_irq(struct irq_data *d)
> +void gic_mask_irq(struct irq_data *d)
>  {
>         u32 mask = 1 << (gic_irq(d) % 32);
>
> @@ -163,7 +163,7 @@ static void gic_mask_irq(struct irq_data *d)
>         raw_spin_unlock(&irq_controller_lock);
>  }
>
> -static void gic_unmask_irq(struct irq_data *d)
> +void gic_unmask_irq(struct irq_data *d)
>  {
>         u32 mask = 1 << (gic_irq(d) % 32);
>
> @@ -768,19 +768,21 @@ void __init gic_init_physaddr(struct device_node *node)
>  static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
>                                 irq_hw_number_t hw)
>  {
> +       struct gic_chip_data *gic = d->host_data;
> +
>         if (hw < 32) {
>                 irq_set_percpu_devid(irq);
> -               irq_set_chip_and_handler(irq, &gic_chip,
> +               irq_set_chip_and_handler(irq, gic->irq_chip,
>                                          handle_percpu_devid_irq);
>                 set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
>         } else {
> -               irq_set_chip_and_handler(irq, &gic_chip,
> +               irq_set_chip_and_handler(irq, gic->irq_chip,
>                                          handle_fasteoi_irq);

And here you should discriminate on whether this is MSI or not, based on
the range you got from above.

>                 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
>
>                 gic_routable_irq_domain_ops->map(d, irq, hw);
>         }
> -       irq_set_chip_data(irq, d->host_data);
> +       irq_set_chip_data(irq, gic);
>         return 0;
>  }
>
> @@ -992,10 +994,11 @@ static int gic_cnt __initdata;
>  static int __init
>  gic_of_init(struct device_node *node, struct device_node *parent)
>  {
> +       struct device_node *child;
>         void __iomem *cpu_base;
>         void __iomem *dist_base;
>         u32 percpu_offset;
> -       int irq;
> +       int irq, ret;
>
>         if (WARN_ON(!node))
>                 return -ENODEV;
> @@ -1009,6 +1012,16 @@ gic_of_init(struct device_node *node, struct device_node *parent)
>         if (of_property_read_u32(node, "cpu-offset", &percpu_offset))
>                 percpu_offset = 0;
>
> +       gic_data[gic_cnt].irq_chip = &gic_chip;
> +
> +       /* Currently, we only support one v2m subnode. */
> +       child = of_get_child_by_name(node, "v2m");

If you only support one v2m node, then you should also enforce it for
potential secondaty GICs (just probing it for gic_cnt == 0 should be
enough).

> +       if (child) {
> +               ret = gicv2m_of_init(child, &gic_data[gic_cnt]);
> +               if (ret)
> +                       return ret;
> +       }
> +
>         gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset, node);
>         if (!gic_cnt)
>                 gic_init_physaddr(node);
> @@ -1020,6 +1033,8 @@ gic_of_init(struct device_node *node, struct device_node *parent)
>         gic_cnt++;
>         return 0;
>  }
> +
> +IRQCHIP_DECLARE(gic_400, "arm,gic-400", gic_of_init);
>  IRQCHIP_DECLARE(cortex_a15_gic, "arm,cortex-a15-gic", gic_of_init);
>  IRQCHIP_DECLARE(cortex_a9_gic, "arm,cortex-a9-gic", gic_of_init);
>  IRQCHIP_DECLARE(msm_8660_qgic, "qcom,msm-8660-qgic", gic_of_init);
> diff --git a/drivers/irqchip/irq-gic.h b/drivers/irqchip/irq-gic.h
> new file mode 100644
> index 0000000..2ec6bc3
> --- /dev/null
> +++ b/drivers/irqchip/irq-gic.h
> @@ -0,0 +1,48 @@
> +#ifndef _IRQ_GIC_H_
> +#define _IRQ_GIC_H_
> +
> +#include <linux/msi.h>
> +
> +union gic_base {
> +       void __iomem *common_base;
> +       void __percpu * __iomem *percpu_base;
> +};
> +
> +#ifdef CONFIG_ARM_GIC_V2M
> +struct v2m_data {
> +       spinlock_t msi_cnt_lock;
> +       struct msi_chip msi_chip;
> +       struct resource res;      /* GICv2m resource */
> +       void __iomem *base;       /* GICv2m virt address */
> +       unsigned int spi_start;   /* The SPI number that MSIs start */
> +       unsigned int nr_spis;     /* The number of SPIs for MSIs */
> +       unsigned long *bm;        /* MSI vector bitmap */
> +};
> +#endif

So if you put the #ifdef/#endif *inside* the v2m_data structure...

> +
> +struct gic_chip_data {
> +       union gic_base dist_base;
> +       union gic_base cpu_base;
> +#ifdef CONFIG_CPU_PM
> +       u32 saved_spi_enable[DIV_ROUND_UP(1020, 32)];
> +       u32 saved_spi_conf[DIV_ROUND_UP(1020, 16)];
> +       u32 saved_spi_target[DIV_ROUND_UP(1020, 4)];
> +       u32 __percpu *saved_ppi_enable;
> +       u32 __percpu *saved_ppi_conf;
> +#endif
> +       struct irq_domain *domain;
> +       unsigned int gic_irqs;
> +#ifdef CONFIG_GIC_NON_BANKED
> +       void __iomem *(*get_base)(union gic_base *);
> +#endif
> +       struct irq_chip *irq_chip;
> +#ifdef CONFIG_ARM_GIC_V2M
> +       struct v2m_data v2m_data;
> +#endif

... you can then get rid of this #ifdef/#endif.

> +};
> +
> +void gic_mask_irq(struct irq_data *d);
> +void gic_unmask_irq(struct irq_data *d);
> +int gicv2m_of_init(struct device_node *node, struct gic_chip_data *gic) __init;
> +
> +#endif /* _IRQ_GIC_H_ */
> --
> 1.9.0
>
>

Thanks,

	M.

Suravee Suthikulpanit Aug. 28, 2014, 8:59 a.m. UTC | #4

On 08/15/2014 09:03 AM, Marc Zyngier wrote:
>> +
>> +static struct irq_chip gicv2m_chip;
>> +
>> +#ifdef CONFIG_OF
>
> Is there any reason why this should be guarded by CONFIG_OF? Surely the
> v2m capability should only be enabled if OF is.

[Suravee]
We are also planning to support ACPI in the future also, which will be 
using a different init function.  Also, there is the same #ifdef in the 
irq-gic.c for the gic_of_init().  So, I am just trying to be consistent 
here.


>> +
>> +       memcpy(&gicv2m_chip, gic->irq_chip, sizeof(struct irq_chip));
>> +       gicv2m_chip.name = "GICv2m",
>> +       gicv2m_chip.irq_mask = gicv2m_mask_irq;
>> +       gicv2m_chip.irq_unmask = gicv2m_unmask_irq;
>> +       gic->irq_chip = &gicv2m_chip;
>
> I liked it until this last line. You're overriding the irq_chip for the
> whole GIC. I was expecting you'd only use it for the MSI range
> (basically return a range to the caller, together with your brand new
> irq_chip).

[Suravee]
I'm not sure if I understand you point here. Actually, I don't see the 
whole point of the need to have a whole different irq_chip for v2m 
stuff.  All I need is just a way to overwrite the irq_chip.irq_mask() 
and irq_chip.irq_unmask() with the v2m version which should check for 
MSI before calling mask/unmask_msi_irq(). I should be able to just do:

	gic->irq_chip.irq_mask = gicv2m_mask_irq;
	gic->irq_chip.irq_unmask = gicv2m_unmask_irq;


>> @@ -768,19 +768,21 @@ void __init gic_init_physaddr(struct device_node *node)
>>   static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
>>                                  irq_hw_number_t hw)
>>   {
>> +       struct gic_chip_data *gic = d->host_data;
>> +
>>          if (hw < 32) {
>>                  irq_set_percpu_devid(irq);
>> -               irq_set_chip_and_handler(irq, &gic_chip,
>> +               irq_set_chip_and_handler(irq, gic->irq_chip,
>>                                           handle_percpu_devid_irq);
>>                  set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
>>          } else {
>> -               irq_set_chip_and_handler(irq, &gic_chip,
>> +               irq_set_chip_and_handler(irq, gic->irq_chip,
>>                                           handle_fasteoi_irq);
>
> And here you should discriminate on whether this is MSI or not, based on
> the range you got from above.
>

[Suravee]
 From above, since we only use one irq_chip (i.e. the gic_chip), there 
is no need to differentiate here, and I don't need to make these two 
line changes.

>> @@ -1009,6 +1012,16 @@ gic_of_init(struct device_node *node, struct device_node *parent)
>>          if (of_property_read_u32(node, "cpu-offset", &percpu_offset))
>>                  percpu_offset = 0;
>>
>> +       gic_data[gic_cnt].irq_chip = &gic_chip;
>> +
>> +       /* Currently, we only support one v2m subnode. */
>> +       child = of_get_child_by_name(node, "v2m");
>
> If you only support one v2m node, then you should also enforce it for
> potential secondaty GICs (just probing it for gic_cnt == 0 should be
> enough).

[Suravee]
Actually, if we have multiple (N) GICs, we should be able to also 
support multiple (N) V2Ms with the followings entries.
	gic0 {
		.....
		v2m {
			....
		}
	}

	gic1 {
		.....
		v2m {
			....
		}
	}

What I am not trying to support at this point is the following:

	gic0 {
		....
		v2m {
			....
		}
		v2m {
			....
		}
	}


>> diff --git a/drivers/irqchip/irq-gic.h b/drivers/irqchip/irq-gic.h
>> new file mode 100644
>> index 0000000..2ec6bc3
>> --- /dev/null
>> +++ b/drivers/irqchip/irq-gic.h
>> @@ -0,0 +1,48 @@
>> +#ifndef _IRQ_GIC_H_
>> +#define _IRQ_GIC_H_
>> +
>> +#include <linux/msi.h>
>> +
>> +union gic_base {
>> +       void __iomem *common_base;
>> +       void __percpu * __iomem *percpu_base;
>> +};
>> +
>> +#ifdef CONFIG_ARM_GIC_V2M
>> +struct v2m_data {
>> +       spinlock_t msi_cnt_lock;
>> +       struct msi_chip msi_chip;
>> +       struct resource res;      /* GICv2m resource */
>> +       void __iomem *base;       /* GICv2m virt address */
>> +       unsigned int spi_start;   /* The SPI number that MSIs start */
>> +       unsigned int nr_spis;     /* The number of SPIs for MSIs */
>> +       unsigned long *bm;        /* MSI vector bitmap */
>> +};
>> +#endif
>
> So if you put the #ifdef/#endif *inside* the v2m_data structure...

[Suravee] Are you suggesting an empty struct v2m_data{}; Hm.. I guess I 
can do that.

Thanks,

Suravee
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to [e-mail]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Suravee Suthikulpanit Aug. 28, 2014, 9:03 a.m. UTC | #5

On 08/14/2014 12:55 PM, Mark Rutland wrote:
> On Wed, Aug 13, 2014 at 04:00:40PM +0100, [e-mail] wrote:
>> From: Suravee Suthikulpanit <[e-mail]>
>>
>> ARM GICv2m specification extends GICv2 to support MSI(-X) with
>> a new set of register frame. This patch introduces support for
>> the non-secure GICv2m register frame. Currently, GICV2m is available
>> in certain version of GIC-400.
>>
>> The patch introduces a new property in ARM gic binding, the v2m subnode.
>> It is optional.
>>
>> Signed-off-by: Suravee Suthikulpanit <[e-mail]>
>> Cc: Mark Rutland <[e-mail]>
>> Cc: Marc Zyngier <[e-mail]>
>> Cc: Jason Cooper <[e-mail]>
>> Cc: Catalin Marinas <[e-mail]>
>> Cc: Will Deacon <[e-mail]>
>> ---
>>   Documentation/devicetree/bindings/arm/gic.txt |  32 ++++
>>   drivers/irqchip/Kconfig                       |   7 +
>>   drivers/irqchip/Makefile                      |   1 +
>>   drivers/irqchip/irq-gic-v2m.c                 | 215 ++++++++++++++++++++++++++
>>   drivers/irqchip/irq-gic.c                     |  75 +++++----
>>   drivers/irqchip/irq-gic.h                     |  48 ++++++
>>   6 files changed, 348 insertions(+), 30 deletions(-)
>>   create mode 100644 drivers/irqchip/irq-gic-v2m.c
>>   create mode 100644 drivers/irqchip/irq-gic.h
>>
>> diff --git a/Documentation/devicetree/bindings/arm/gic.txt b/Documentation/devicetree/bindings/arm/gic.txt
>> index 5573c08..8a64179 100644
>> --- a/Documentation/devicetree/bindings/arm/gic.txt
>> +++ b/Documentation/devicetree/bindings/arm/gic.txt
>> @@ -95,3 +95,35 @@ Example:
>>                        <0x2c006000 0x2000>;
>>                  interrupts = <1 9 0xf04>;
>>          };
>> +
>> +
>> +* GICv2m extension for MSI/MSI-x support (Optional)
>> +
>> +Certain revision of GIC-400 supports MSI/MSI-x via V2M register frame.
>> +This is enabled by specifying v2m sub-node.
>> +
>> +Required properties:
>> +
>> +- msi-controller : Identifies the node as an MSI controller.
>> +
>> +- reg : GICv2m MSI interface register base and size
>> +
>> +Example:
>> +
>> +       interrupt-controller@e1101000 {
>> +               compatible = "arm,gic-400";
>> +               #interrupt-cells = <3>;
>> +               #address-cells = <2>;
>> +               #size-cells = <2>;
>> +               interrupt-controller;
>> +               interrupts = <1 8 0xf04>;
>> +               ranges = <0 0 0 0xe1100000 0 0x100000>;
>> +               reg = <0x0 0xe1110000 0 0x01000>,
>> +                     <0x0 0xe112f000 0 0x02000>,
>> +                     <0x0 0xe1140000 0 0x10000>,
>> +                     <0x0 0xe1160000 0 0x10000>;
>> +               v2m {
>> +                       msi-controller;
>> +                       reg = <0x0 0x80000 0 0x1000>;
>> +               };
>> +       };
>
> [...]
>
>> @@ -1009,6 +1012,16 @@ gic_of_init(struct device_node *node, struct device_node *parent)
>>          if (of_property_read_u32(node, "cpu-offset", &percpu_offset))
>>                  percpu_offset = 0;
>>
>> +       gic_data[gic_cnt].irq_chip = &gic_chip;
>> +
>> +       /* Currently, we only support one v2m subnode. */
>> +       child = of_get_child_by_name(node, "v2m");
>> +       if (child) {
>> +               ret = gicv2m_of_init(child, &gic_data[gic_cnt]);
>> +               if (ret)
>> +                       return ret;
>> +       }
>
> I can't see how you'd sanely expand this to multiple children, which was
> the main point of having a separate node for the M block.
>
> Give the M block a compatible string and look for children with that
> string.
>
> Thanks,
> Mark.
>
Good point. I can try that.

Thank,

Suravee
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to [e-mail]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Suravee Suthikulpanit Aug. 28, 2014, 9:15 a.m. UTC | #6

On 08/13/2014 09:56 PM, Jingoo Han wrote:
> On Thursday, August 14, 2014 12:01 AM, Suravee Suthikulpanit wrote:
>>
>> From: Suravee Suthikulpanit <[e-mail]>
>>
>> ARM GICv2m specification extends GICv2 to support MSI(-X) with
>> a new set of register frame. This patch introduces support for
>> the non-secure GICv2m register frame. Currently, GICV2m is available
>> in certain version of GIC-400.
>>
>> The patch introduces a new property in ARM gic binding, the v2m subnode.
>> It is optional.
>
> Hi Suravee Suthikulpanit,
>
> I added some minor comments.

Thanks for the cleaning up comments.

Suravee
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to [e-mail]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Marc Zyngier Sept. 5, 2014, 4:15 p.m. UTC | #7

On 28/08/14 09:59, Suravee Suthikulpanit wrote:
> 
> 
> On 08/15/2014 09:03 AM, Marc Zyngier wrote:
>>> +
>>> +static struct irq_chip gicv2m_chip;
>>> +
>>> +#ifdef CONFIG_OF
>>
>> Is there any reason why this should be guarded by CONFIG_OF? Surely the
>> v2m capability should only be enabled if OF is.
> 
> [Suravee]
> We are also planning to support ACPI in the future also, which will be 
> using a different init function.  Also, there is the same #ifdef in the 
> irq-gic.c for the gic_of_init().  So, I am just trying to be consistent 
> here.
> 
> 
>>> +
>>> +       memcpy(&gicv2m_chip, gic->irq_chip, sizeof(struct irq_chip));
>>> +       gicv2m_chip.name = "GICv2m",
>>> +       gicv2m_chip.irq_mask = gicv2m_mask_irq;
>>> +       gicv2m_chip.irq_unmask = gicv2m_unmask_irq;
>>> +       gic->irq_chip = &gicv2m_chip;
>>
>> I liked it until this last line. You're overriding the irq_chip for the
>> whole GIC. I was expecting you'd only use it for the MSI range
>> (basically return a range to the caller, together with your brand new
>> irq_chip).
> 
> [Suravee]
> I'm not sure if I understand you point here. Actually, I don't see the 
> whole point of the need to have a whole different irq_chip for v2m 
> stuff.  All I need is just a way to overwrite the irq_chip.irq_mask() 
> and irq_chip.irq_unmask() with the v2m version which should check for 
> MSI before calling mask/unmask_msi_irq(). I should be able to just do:
> 
> 	gic->irq_chip.irq_mask = gicv2m_mask_irq;
> 	gic->irq_chip.irq_unmask = gicv2m_unmask_irq;

You should only do it for the few interrupts that are actually routed
via the v2m widget, not inflict the overhead on all interrupts.

This is why I insist on having a separate irqchip, and for this irqchip
to be only used for the MSI-generated interrupts.

Have a look at what I do for GICv3:
http://git.kernel.org/cgit/linux/kernel/git/maz/arm-platforms.git/tree/drivers/irqchip/irq-gic-v3.c?h=gicv3/its-split&id=b717e532c4312a410a8ee0cb2349baa2769c6b94#n712

and how this gets used when routing the interrupts:
http://git.kernel.org/cgit/linux/kernel/git/maz/arm-platforms.git/tree/drivers/irqchip/irq-gic-v3.c?h=gicv3/its-split&id=b717e532c4312a410a8ee0cb2349baa2769c6b94#n589

The ITS gets its own irqchip, entirely separate from the rest of the
GIC. This gives you the flexibility you require, and let the other
interrupts free of any overhead.

Thanks,

	M.

Suravee Suthikulpanit Sept. 8, 2014, 11:05 p.m. UTC | #8

On 8/14/2014 12:55 PM, Mark Rutland wrote:
> On Wed, Aug 13, 2014 at 04:00:40PM +0100, [e-mail] wrote:
>> From: Suravee Suthikulpanit <[e-mail]>
>>
>> ARM GICv2m specification extends GICv2 to support MSI(-X) with
>> a new set of register frame. This patch introduces support for
>> the non-secure GICv2m register frame. Currently, GICV2m is available
>> in certain version of GIC-400.
>>
>> The patch introduces a new property in ARM gic binding, the v2m subnode.
>> It is optional.
>>
>> Signed-off-by: Suravee Suthikulpanit <[e-mail]>
>> Cc: Mark Rutland <[e-mail]>
>> Cc: Marc Zyngier <[e-mail]>
>> Cc: Jason Cooper <[e-mail]>
>> Cc: Catalin Marinas <[e-mail]>
>> Cc: Will Deacon <[e-mail]>
>> ---
>>   Documentation/devicetree/bindings/arm/gic.txt |  32 ++++
>>   drivers/irqchip/Kconfig                       |   7 +
>>   drivers/irqchip/Makefile                      |   1 +
>>   drivers/irqchip/irq-gic-v2m.c                 | 215 ++++++++++++++++++++++++++
>>   drivers/irqchip/irq-gic.c                     |  75 +++++----
>>   drivers/irqchip/irq-gic.h                     |  48 ++++++
>>   6 files changed, 348 insertions(+), 30 deletions(-)
>>   create mode 100644 drivers/irqchip/irq-gic-v2m.c
>>   create mode 100644 drivers/irqchip/irq-gic.h
>>
>> diff --git a/Documentation/devicetree/bindings/arm/gic.txt b/Documentation/devicetree/bindings/arm/gic.txt
>> index 5573c08..8a64179 100644
>> --- a/Documentation/devicetree/bindings/arm/gic.txt
>> +++ b/Documentation/devicetree/bindings/arm/gic.txt
>> @@ -95,3 +95,35 @@ Example:
>>                        <0x2c006000 0x2000>;
>>                  interrupts = <1 9 0xf04>;
>>          };
>> +
>> +
>> +* GICv2m extension for MSI/MSI-x support (Optional)
>> +
>> +Certain revision of GIC-400 supports MSI/MSI-x via V2M register frame.
>> +This is enabled by specifying v2m sub-node.
>> +
>> +Required properties:
>> +
>> +- msi-controller : Identifies the node as an MSI controller.
>> +
>> +- reg : GICv2m MSI interface register base and size
>> +
>> +Example:
>> +
>> +       interrupt-controller@e1101000 {
>> +               compatible = "arm,gic-400";
>> +               #interrupt-cells = <3>;
>> +               #address-cells = <2>;
>> +               #size-cells = <2>;
>> +               interrupt-controller;
>> +               interrupts = <1 8 0xf04>;
>> +               ranges = <0 0 0 0xe1100000 0 0x100000>;
>> +               reg = <0x0 0xe1110000 0 0x01000>,
>> +                     <0x0 0xe112f000 0 0x02000>,
>> +                     <0x0 0xe1140000 0 0x10000>,
>> +                     <0x0 0xe1160000 0 0x10000>;
>> +               v2m {
>> +                       msi-controller;
>> +                       reg = <0x0 0x80000 0 0x1000>;
>> +               };
>> +       };
>
> [...]
>
>> @@ -1009,6 +1012,16 @@ gic_of_init(struct device_node *node, struct device_node *parent)
>>          if (of_property_read_u32(node, "cpu-offset", &percpu_offset))
>>                  percpu_offset = 0;
>>
>> +       gic_data[gic_cnt].irq_chip = &gic_chip;
>> +
>> +       /* Currently, we only support one v2m subnode. */
>> +       child = of_get_child_by_name(node, "v2m");
>> +       if (child) {
>> +               ret = gicv2m_of_init(child, &gic_data[gic_cnt]);
>> +               if (ret)
>> +                       return ret;
>> +       }
>
> I can't see how you'd sanely expand this to multiple children, which was
> the main point of having a separate node for the M block.
>
> Give the M block a compatible string and look for children with that
> string.

Mark,

I am making change in the struct gic_chip_data to contain "v2m_list" (instead of just
a single struct v2m_data). This way, it is clear on how we should handle multiple v2m nodes
within a GIC.

As for the device tree binding, in order to handle multiple v2m nodes within a GIC,
it should not require adding another compatibility ID as it seems too complicate
to have GIC node with multiple compat IDs).

	v2m0 {
		msi-controller;
		reg = <0 0x80000 0 0x10000>;	
	};

	v2m1 {
		msi-controller;
		reg = <0 0x90000 0 0x10000>;
	};

This should work since the PCI controller uses "of_pci_find_msi_chip_by_node()" to locate the msi_chip,
we can simply just use "v2m0" or "v2m1" to specify this.

Thanks,

Suravee.

--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to [e-mail]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Mark Rutland Sept. 9, 2014, 11:03 a.m. UTC | #9

[...]

> >> @@ -1009,6 +1012,16 @@ gic_of_init(struct device_node *node, struct device_node *parent)
> >>          if (of_property_read_u32(node, "cpu-offset", &percpu_offset))
> >>                  percpu_offset = 0;
> >>
> >> +       gic_data[gic_cnt].irq_chip = &gic_chip;
> >> +
> >> +       /* Currently, we only support one v2m subnode. */
> >> +       child = of_get_child_by_name(node, "v2m");
> >> +       if (child) {
> >> +               ret = gicv2m_of_init(child, &gic_data[gic_cnt]);
> >> +               if (ret)
> >> +                       return ret;
> >> +       }
> >
> > I can't see how you'd sanely expand this to multiple children, which was
> > the main point of having a separate node for the M block.
> >
> > Give the M block a compatible string and look for children with that
> > string.
> 
> Mark,
> 
> I am making change in the struct gic_chip_data to contain "v2m_list" (instead of just
> a single struct v2m_data). This way, it is clear on how we should handle multiple v2m nodes
> within a GIC.

Ok.

> As for the device tree binding, in order to handle multiple v2m nodes within a GIC,
> it should not require adding another compatibility ID as it seems too complicate
> to have GIC node with multiple compat IDs).

I don't follow.

How does each sub-node having a compatible string complicate the GIC
node?

Mark.
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to [e-mail]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch

diff --git a/Documentation/devicetree/bindings/arm/gic.txt b/Documentation/devicetree/bindings/arm/gic.txt
index 5573c08..8a64179 100644
--- a/Documentation/devicetree/bindings/arm/gic.txt
+++ b/Documentation/devicetree/bindings/arm/gic.txt
@@ -95,3 +95,35 @@  Example:
 		      <0x2c006000 0x2000>;
 		interrupts = <1 9 0xf04>;
 	};
+
+
+* GICv2m extension for MSI/MSI-x support (Optional)
+
+Certain revision of GIC-400 supports MSI/MSI-x via V2M register frame.
+This is enabled by specifying v2m sub-node.
+
+Required properties:
+
+- msi-controller : Identifies the node as an MSI controller.
+
+- reg : GICv2m MSI interface register base and size
+
+Example:
+
+	interrupt-controller@e1101000 {
+		compatible = "arm,gic-400";
+		#interrupt-cells = <3>;
+		#address-cells = <2>;
+		#size-cells = <2>;
+		interrupt-controller;
+		interrupts = <1 8 0xf04>;
+		ranges = <0 0 0 0xe1100000 0 0x100000>;
+		reg = <0x0 0xe1110000 0 0x01000>,
+		      <0x0 0xe112f000 0 0x02000>,
+		      <0x0 0xe1140000 0 0x10000>,
+		      <0x0 0xe1160000 0 0x10000>;
+		v2m {
+			msi-controller;
+			reg = <0x0 0x80000 0 0x1000>;
+		};
+	};
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 4e230e7..9aa5edc 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -7,6 +7,13 @@  config ARM_GIC
 	select IRQ_DOMAIN
 	select MULTI_IRQ_HANDLER
 
+config ARM_GIC_V2M
+	bool
+	select IRQ_DOMAIN
+	select MULTI_IRQ_HANDLER
+	depends on ARM_GIC
+	depends on PCI && PCI_MSI
+
 config GIC_NON_BANKED
 	bool
 
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 73052ba..3bda951 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -17,6 +17,7 @@  obj-$(CONFIG_ARCH_SUNXI)		+= irq-sun4i.o
 obj-$(CONFIG_ARCH_SUNXI)		+= irq-sunxi-nmi.o
 obj-$(CONFIG_ARCH_SPEAR3XX)		+= spear-shirq.o
 obj-$(CONFIG_ARM_GIC)			+= irq-gic.o irq-gic-common.o
+obj-$(CONFIG_ARM_GIC_V2M)		+= irq-gic-v2m.o
 obj-$(CONFIG_ARM_GIC_V3)		+= irq-gic-v3.o irq-gic-common.o
 obj-$(CONFIG_ARM_NVIC)			+= irq-nvic.o
 obj-$(CONFIG_ARM_VIC)			+= irq-vic.o
diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c
new file mode 100644
index 0000000..1ac0ace
--- /dev/null
+++ b/drivers/irqchip/irq-gic-v2m.c
@@ -0,0 +1,215 @@ 
+/*
+ * ARM GIC v2m MSI(-X) support
+ * Support for Message Signalelled Interrupts for systems that
+ * implement ARM Generic Interrupt Controller: GICv2m.
+ *
+ * Copyright (C) 2014 Advanced Micro Devices, Inc.
+ * Authors: Suravee Suthikulpanit <[e-mail]>
+ *          Harish Kasiviswanathan <[e-mail]>
+ *          Brandon Anderson <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pci.h>
+#include <linux/irq.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/bitmap.h>
+
+#include "irqchip.h"
+#include "irq-gic.h"
+
+/*
+* MSI_TYPER:
+*     [31:26] Reserved
+*     [25:16] lowest SPI assigned to MSI
+*     [15:10] Reserved
+*     [9:0]   Numer of SPIs assigned to MSI
+*/
+#define V2M_MSI_TYPER			0x008
+#define V2M_MSI_TYPER_BASE_SHIFT	(16)
+#define V2M_MSI_TYPER_BASE_MASK		(0x3FF)
+#define V2M_MSI_TYPER_NUM_MASK		(0x3FF)
+#define V2M_MSI_SETSPI_NS		0x040
+#define V2M_MIN_SPI			32
+#define V2M_MAX_SPI			1019
+
+/*
+ * alloc_msi_irq - Allocate MSIs from avaialbe MSI bitmap.
+ * @data: Pointer to v2m_data
+ * @nvec: Number of interrupts to allocate
+ * @irq: Pointer to the allocated irq
+ *
+ * Allocates interrupts only if the contiguous range of MSIs
+ * with specified nvec are available. Otherwise return the number
+ * of available interrupts. If none are available, then returns -ENOENT.
+ */
+static int alloc_msi_irq(struct v2m_data *data, int nvec, int *irq)
+{
+	int size = data->nr_spis;
+	int next = size, i = nvec, ret;
+
+	/* We should never allocate more than available nr_spis */
+	if (i >= size)
+		i = size;
+
+	spin_lock(&data->msi_cnt_lock);
+
+	for (; i > 0; i--) {
+		next = bitmap_find_next_zero_area(data->bm,
+					size, 0, i, 0);
+		if (next < size)
+			break;
+	}
+
+	if (i != nvec) {
+		ret = i ? : -ENOENT;
+	} else {
+		bitmap_set(data->bm, next, nvec);
+		*irq = data->spi_start + next;
+		ret = 0;
+	}
+
+	spin_unlock(&data->msi_cnt_lock);
+
+	return ret;
+}
+
+static void gicv2m_teardown_msi_irq(struct msi_chip *chip, unsigned int irq)
+{
+	int pos;
+	struct v2m_data *data = container_of(chip, struct v2m_data, msi_chip);
+
+	spin_lock(&data->msi_cnt_lock);
+
+	pos = irq - data->spi_start;
+	if (pos >= 0 && pos < data->nr_spis)
+		bitmap_clear(data->bm, pos, 1);
+
+	spin_unlock(&data->msi_cnt_lock);
+}
+
+static int gicv2m_setup_msi_irq(struct msi_chip *chip, struct pci_dev *pdev,
+		      struct msi_desc *desc)
+{
+	int avail, irq = 0;
+	struct msi_msg msg;
+	phys_addr_t addr;
+	struct v2m_data *data = container_of(chip, struct v2m_data, msi_chip);
+
+	if (!desc) {
+		dev_err(&pdev->dev,
+			"GICv2m: MSI setup failed. Invalid msi descriptor\n");
+		return -EINVAL;
+	}
+
+	avail = alloc_msi_irq(data, 1, &irq);
+	if (avail != 0) {
+		dev_err(&pdev->dev,
+			"GICv2m: MSI setup failed. Cannnot allocate IRQ\n");
+		return -ENOSPC;
+	}
+
+	irq_set_chip_data(irq, chip);
+	irq_set_msi_desc(irq, desc);
+	irq_set_irq_type(irq, IRQ_TYPE_EDGE_RISING);
+
+	addr = data->res.start + V2M_MSI_SETSPI_NS;
+
+	msg.address_hi = (u32)(addr >> 32);
+	msg.address_lo = (u32)(addr);
+	msg.data = irq;
+	write_msi_msg(irq, &msg);
+
+	return 0;
+}
+
+static void gicv2m_mask_irq(struct irq_data *d)
+{
+	gic_mask_irq(d);
+	if (d->msi_desc)
+		mask_msi_irq(d);
+}
+
+static void gicv2m_unmask_irq(struct irq_data *d)
+{
+	gic_unmask_irq(d);
+	if (d->msi_desc)
+		unmask_msi_irq(d);
+}
+
+static struct irq_chip gicv2m_chip;
+
+#ifdef CONFIG_OF
+int __init
+gicv2m_of_init(struct device_node *node, struct gic_chip_data *gic)
+{
+	int ret;
+	unsigned int val;
+	struct v2m_data *v2m = &gic->v2m_data;
+
+	v2m->msi_chip.owner = THIS_MODULE;
+	v2m->msi_chip.of_node = node;
+	v2m->msi_chip.setup_irq = gicv2m_setup_msi_irq;
+	v2m->msi_chip.teardown_irq = gicv2m_teardown_msi_irq;
+	ret = of_pci_msi_chip_add(&v2m->msi_chip);
+	if (ret) {
+		pr_info("GICv2m: Failed to add msi_chip.\n");
+		return ret;
+	}
+
+	if (of_address_to_resource(node, 0, &v2m->res)) {
+		pr_err("GICv2m: Failed locate GICv2m MSI register frame\n");
+		return -EINVAL;
+	}
+
+	v2m->base = of_iomap(node, 0);
+	if (!v2m->base) {
+		pr_err("GICv2m: Failed to map GIC MSI registers\n");
+		return -EINVAL;
+	}
+
+	val = readl_relaxed(v2m->base + V2M_MSI_TYPER);
+	if (!val) {
+		pr_warn("GICv2m: Failed to read V2M_MSI_TYPER register\n");
+		return -EINVAL;
+	}
+
+	v2m->spi_start = (val >> V2M_MSI_TYPER_BASE_SHIFT) &
+				V2M_MSI_TYPER_BASE_MASK;
+	v2m->nr_spis = val & V2M_MSI_TYPER_NUM_MASK;
+	if ((v2m->spi_start < V2M_MIN_SPI) || (v2m->nr_spis >= V2M_MAX_SPI)) {
+			pr_err("GICv2m: Invalid MSI_TYPER (%#x)\n", val);
+			return -EINVAL;
+	}
+
+	v2m->bm = kzalloc(sizeof(long) * BITS_TO_LONGS(v2m->nr_spis),
+			  GFP_KERNEL);
+	if (!v2m->bm) {
+		pr_err("GICv2m: Failed to allocate MSI bitmap\n");
+		return -ENOMEM;
+	}
+
+	spin_lock_init(&v2m->msi_cnt_lock);
+
+	pr_info("GICv2m: SPI range [%d:%d]\n",
+		v2m->spi_start, (v2m->spi_start + v2m->nr_spis));
+
+	memcpy(&gicv2m_chip, gic->irq_chip, sizeof(struct irq_chip));
+	gicv2m_chip.name = "GICv2m",
+	gicv2m_chip.irq_mask = gicv2m_mask_irq;
+	gicv2m_chip.irq_unmask = gicv2m_unmask_irq;
+	gic->irq_chip = &gicv2m_chip;
+
+	return 0;
+}
+
+#endif /* CONFIG_OF */
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 508b815..b175ccf 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -47,30 +47,9 @@ 
 #include <asm/smp_plat.h>
 
 #include "irq-gic-common.h"
+#include "irq-gic.h"
 #include "irqchip.h"
 
-union gic_base {
-	void __iomem *common_base;
-	void __percpu * __iomem *percpu_base;
-};
-
-struct gic_chip_data {
-	union gic_base dist_base;
-	union gic_base cpu_base;
-#ifdef CONFIG_CPU_PM
-	u32 saved_spi_enable[DIV_ROUND_UP(1020, 32)];
-	u32 saved_spi_conf[DIV_ROUND_UP(1020, 16)];
-	u32 saved_spi_target[DIV_ROUND_UP(1020, 4)];
-	u32 __percpu *saved_ppi_enable;
-	u32 __percpu *saved_ppi_conf;
-#endif
-	struct irq_domain *domain;
-	unsigned int gic_irqs;
-#ifdef CONFIG_GIC_NON_BANKED
-	void __iomem *(*get_base)(union gic_base *);
-#endif
-};
-
 static DEFINE_RAW_SPINLOCK(irq_controller_lock);
 
 /*
@@ -132,15 +111,36 @@  static inline void gic_set_base_accessor(struct gic_chip_data *data,
 #define gic_set_base_accessor(d, f)
 #endif
 
+static inline
+struct gic_chip_data *irq_data_get_gic_chip_data(struct irq_data *d)
+{
+	struct gic_chip_data *gic_data;
+	struct msi_chip *mchip;
+	struct v2m_data *v2mdat;
+
+	/*
+	 * For MSI, irq_data.chip_data points to struct msi_chip.
+	 * For non-MSI, irq_data.chip_data points to struct gic_chip_data.
+	 */
+	if (d->msi_desc) {
+		mchip = irq_data_get_irq_chip_data(d);
+		v2mdat = container_of(mchip, struct v2m_data, msi_chip);
+		gic_data = container_of(v2mdat, struct gic_chip_data, v2m_data);
+	} else {
+		gic_data = irq_data_get_irq_chip_data(d);
+	}
+	return gic_data;
+}
+
 static inline void __iomem *gic_dist_base(struct irq_data *d)
 {
-	struct gic_chip_data *gic_data = irq_data_get_irq_chip_data(d);
+	struct gic_chip_data *gic_data = irq_data_get_gic_chip_data(d);
 	return gic_data_dist_base(gic_data);
 }
 
 static inline void __iomem *gic_cpu_base(struct irq_data *d)
 {
-	struct gic_chip_data *gic_data = irq_data_get_irq_chip_data(d);
+	struct gic_chip_data *gic_data = irq_data_get_gic_chip_data(d);
 	return gic_data_cpu_base(gic_data);
 }
 
@@ -152,7 +152,7 @@  static inline unsigned int gic_irq(struct irq_data *d)
 /*
  * Routines to acknowledge, disable and enable interrupts
  */
-static void gic_mask_irq(struct irq_data *d)
+void gic_mask_irq(struct irq_data *d)
 {
 	u32 mask = 1 << (gic_irq(d) % 32);
 
@@ -163,7 +163,7 @@  static void gic_mask_irq(struct irq_data *d)
 	raw_spin_unlock(&irq_controller_lock);
 }
 
-static void gic_unmask_irq(struct irq_data *d)
+void gic_unmask_irq(struct irq_data *d)
 {
 	u32 mask = 1 << (gic_irq(d) % 32);
 
@@ -768,19 +768,21 @@  void __init gic_init_physaddr(struct device_node *node)
 static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
 				irq_hw_number_t hw)
 {
+	struct gic_chip_data *gic = d->host_data;
+
 	if (hw < 32) {
 		irq_set_percpu_devid(irq);
-		irq_set_chip_and_handler(irq, &gic_chip,
+		irq_set_chip_and_handler(irq, gic->irq_chip,
 					 handle_percpu_devid_irq);
 		set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
 	} else {
-		irq_set_chip_and_handler(irq, &gic_chip,
+		irq_set_chip_and_handler(irq, gic->irq_chip,
 					 handle_fasteoi_irq);
 		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
 
 		gic_routable_irq_domain_ops->map(d, irq, hw);
 	}
-	irq_set_chip_data(irq, d->host_data);
+	irq_set_chip_data(irq, gic);
 	return 0;
 }
 
@@ -992,10 +994,11 @@  static int gic_cnt __initdata;
 static int __init
 gic_of_init(struct device_node *node, struct device_node *parent)
 {
+	struct device_node *child;
 	void __iomem *cpu_base;
 	void __iomem *dist_base;
 	u32 percpu_offset;
-	int irq;
+	int irq, ret;
 
 	if (WARN_ON(!node))
 		return -ENODEV;
@@ -1009,6 +1012,16 @@  gic_of_init(struct device_node *node, struct device_node *parent)
 	if (of_property_read_u32(node, "cpu-offset", &percpu_offset))
 		percpu_offset = 0;
 
+	gic_data[gic_cnt].irq_chip = &gic_chip;
+
+	/* Currently, we only support one v2m subnode. */
+	child = of_get_child_by_name(node, "v2m");
+	if (child) {
+		ret = gicv2m_of_init(child, &gic_data[gic_cnt]);
+		if (ret)
+			return ret;
+	}
+
 	gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset, node);
 	if (!gic_cnt)
 		gic_init_physaddr(node);
@@ -1020,6 +1033,8 @@  gic_of_init(struct device_node *node, struct device_node *parent)
 	gic_cnt++;
 	return 0;
 }
+
+IRQCHIP_DECLARE(gic_400, "arm,gic-400", gic_of_init);
 IRQCHIP_DECLARE(cortex_a15_gic, "arm,cortex-a15-gic", gic_of_init);
 IRQCHIP_DECLARE(cortex_a9_gic, "arm,cortex-a9-gic", gic_of_init);
 IRQCHIP_DECLARE(msm_8660_qgic, "qcom,msm-8660-qgic", gic_of_init);
diff --git a/drivers/irqchip/irq-gic.h b/drivers/irqchip/irq-gic.h
new file mode 100644
index 0000000..2ec6bc3
--- /dev/null
+++ b/drivers/irqchip/irq-gic.h
@@ -0,0 +1,48 @@ 
+#ifndef _IRQ_GIC_H_
+#define _IRQ_GIC_H_
+
+#include <linux/msi.h>
+
+union gic_base {
+	void __iomem *common_base;
+	void __percpu * __iomem *percpu_base;
+};
+
+#ifdef CONFIG_ARM_GIC_V2M
+struct v2m_data {
+	spinlock_t msi_cnt_lock;
+	struct msi_chip msi_chip;
+	struct resource res;      /* GICv2m resource */
+	void __iomem *base;       /* GICv2m virt address */
+	unsigned int spi_start;   /* The SPI number that MSIs start */
+	unsigned int nr_spis;     /* The number of SPIs for MSIs */
+	unsigned long *bm;        /* MSI vector bitmap */
+};
+#endif
+
+struct gic_chip_data {
+	union gic_base dist_base;
+	union gic_base cpu_base;
+#ifdef CONFIG_CPU_PM
+	u32 saved_spi_enable[DIV_ROUND_UP(1020, 32)];
+	u32 saved_spi_conf[DIV_ROUND_UP(1020, 16)];
+	u32 saved_spi_target[DIV_ROUND_UP(1020, 4)];
+	u32 __percpu *saved_ppi_enable;
+	u32 __percpu *saved_ppi_conf;
+#endif
+	struct irq_domain *domain;
+	unsigned int gic_irqs;
+#ifdef CONFIG_GIC_NON_BANKED
+	void __iomem *(*get_base)(union gic_base *);
+#endif
+	struct irq_chip *irq_chip;
+#ifdef CONFIG_ARM_GIC_V2M
+	struct v2m_data v2m_data;
+#endif
+};
+
+void gic_mask_irq(struct irq_data *d);
+void gic_unmask_irq(struct irq_data *d);
+int gicv2m_of_init(struct device_node *node, struct gic_chip_data *gic) __init;
+
+#endif /* _IRQ_GIC_H_ */