[RFC 4/4] irqchip: gicv2m: Add supports for ARM GICv2m MSI(-X)

suravee.suthikulpanit
2014-09-28T20:55:12Z

From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>

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.

Cc: Marc Zyngier <Marc.Zyngier@arm.com>
Cc: Mark Rutland <Mark.Rutland@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Catalin Marinas <Catalin.Marinas@arm.com>
Cc: Will Deacon <Will.Deacon@arm.com>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
---
Documentation/devicetree/bindings/arm/gic.txt | 53 +++++
arch/arm64/Kconfig | 1 +
drivers/irqchip/Kconfig | 5 +
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-gic-v2m.c | 301 ++++++++++++++++++++++++++
drivers/irqchip/irq-gic.c | 82 ++++---
drivers/irqchip/irq-gic.h | 54 +++++
7 files changed, 467 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 c7d2fa1..ebf976a 100644
--- a/Documentation/devicetree/bindings/arm/gic.txt
+++ b/Documentation/devicetree/bindings/arm/gic.txt
@@ -96,3 +96,56 @@ Example:
<0x2c006000 0x2000>;
interrupts = <1 9 0xf04>;
};
+
+
+* GICv2m extension for MSI/MSI-x support (Optional)
+
+Certain revisions of GIC-400 supports MSI/MSI-x via V2M register frame(s).
+This is enabled by specifying v2m sub-node(s).
+
+Required properties:
+
+- compatible : The value here should contain "arm,gic-v2m-frame".
+
+- msi-controller : Identifies the node as an MSI controller.
+
+- reg : GICv2m MSI interface register base and size
+
+Optional properties:
+
+- arm,msi-base-spi : When the MSI_TYPER register contains an incorrect
+ value, this property should contain the SPI base of
+ the MSI frame, overriding the HW value.
+
+- arm,msi-num-spis : When the MSI_TYPER register contains an incorrect
+ value, this property should contain the number of
+ SPIs assigned to the frame, overriding the HW value.
+
+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>;
+ v2m0: v2m@0x8000 {
+ compatible = "arm,gic-v2m-frame";
+ msi-controller;
+ reg = <0x0 0x80000 0 0x1000>;
+ };
+
+ ....
+
+ v2mN: v2m@0x9000 {
+ compatible = "arm,gic-v2m-frame";
+ msi-controller;
+ reg = <0x0 0x90000 0 0x1000>;
+ };
+ };
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 6b01df9..01927e5 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -12,6 +12,7 @@ config ARM64
select ARM_ARCH_TIMER
select ARM_GIC
select AUDIT_ARCH_COMPAT_GENERIC
+ select ARM_GIC_V2M
select ARM_GIC_V3
select BUILDTIME_EXTABLE_SORT
select CLONE_BACKWARDS
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index b8632bf..61d18d9 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -7,6 +7,11 @@ config ARM_GIC
select IRQ_DOMAIN
select MULTI_IRQ_HANDLER

+config ARM_GIC_V2M
+ bool
+ 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..725b8a4
--- /dev/null
+++ b/drivers/irqchip/irq-gic-v2m.c
@@ -0,0 +1,301 @@
+/*
+ * ARM GIC v2m MSI(-X) support
+ * Support for Message Signaled Interrupts for systems that
+ * implement ARM Generic Interrupt Controller: GICv2m.
+ *
+ * Copyright (C) 2014 Advanced Micro Devices, Inc.
+ * Authors: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
+ * Harish Kasiviswanathan <harish.kasiviswanathan@amd.com>
+ * Brandon Anderson <brandon.anderson@amd.com>
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) "GICv2m: " fmt
+
+#include <linux/bitmap.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include "irqchip.h"
+#include "irq-gic.h"
+#include "irq-gic-common.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
+
+#define V2M_MSI_TYPER_BASE_SPI(x) \
+ (((x) >> V2M_MSI_TYPER_BASE_SHIFT) & V2M_MSI_TYPER_BASE_MASK)
+
+#define V2M_MSI_TYPER_NUM_SPI(x) ((x) & V2M_MSI_TYPER_NUM_MASK)
+
+/*
+ * alloc_msi_irq - Allocate MSIs from available 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);
+}
+
+bool gicv2m_check_msi_range(struct gic_chip_data *gic, irq_hw_number_t hw)
+{
+ struct v2m_data *v2m = NULL;
+
+ list_for_each_entry(v2m, &gic->v2m_list, list) {
+ if (hw >= v2m->spi_start &&
+ hw < v2m->spi_start + v2m->nr_spis)
+ return true;
+ }
+ return false;
+}
+
+static int gicv2m_setup_msi_irq(struct msi_chip *chip,
+ struct pci_dev *pdev,
+ struct msi_desc *desc)
+{
+ int irq = 0, avail;
+ 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,
+ "MSI setup failed. Invalid msi descriptor\n");
+ return -EINVAL;
+ }
+
+ avail = alloc_msi_irq(data, 1, &irq);
+ if (avail != 0) {
+ dev_err(&pdev->dev,
+ "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 bool is_msi_spi_valid(u32 base, u32 num)
+{
+ if (base < V2M_MIN_SPI) {
+ pr_err("Invalid MSI base SPI (base:%u)\n", base);
+ return false;
+ }
+
+ if ((num == 0) || (base + num > V2M_MAX_SPI)) {
+ pr_err("Number of SPIs (%u) exceed maximum (%u)\n",
+ num, V2M_MAX_SPI - V2M_MIN_SPI + 1);
+ return false;
+ }
+
+ return true;
+}
+
+static int __init
+gicv2m_init_one(struct device_node *node, struct v2m_data **v,
+ struct gic_chip_data *gic)
+{
+ int ret;
+ struct v2m_data *v2m = NULL;
+
+ *v = kzalloc(sizeof(struct v2m_data), GFP_KERNEL);
+ if (!*v) {
+ pr_err("Failed to allocate struct v2m_data.\n");
+ return -ENOMEM;
+ }
+
+ v2m = *v;
+ v2m->gic = gic;
+ 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_address_to_resource(node, 0, &v2m->res);
+ if (ret) {
+ pr_err("Failed to allocate v2m resource.\n");
+ goto err_out;
+ }
+
+ v2m->base = ioremap(v2m->res.start, resource_size(&v2m->res));
+ if (!v2m->base) {
+ pr_err("Failed to map GICv2m resource\n");
+ ret = -EINVAL;
+ goto err_out;
+ }
+
+ ret = of_pci_msi_chip_add(&v2m->msi_chip);
+ if (ret) {
+ pr_info("Failed to add msi_chip.\n");
+ goto err_out;
+ }
+
+ if (!of_property_read_u32(node, "arm,msi-base-spi", &v2m->spi_start) &&
+ !of_property_read_u32(node, "arm,msi-num-spis", &v2m->nr_spis)) {
+ pr_info("Overriding V2M MSI_TYPER (base:%u, num:%u)\n",
+ v2m->spi_start, v2m->nr_spis);
+ } else {
+ u32 typer = readl_relaxed(v2m->base + V2M_MSI_TYPER);
+
+ v2m->spi_start = V2M_MSI_TYPER_BASE_SPI(typer);
+ v2m->nr_spis = V2M_MSI_TYPER_NUM_SPI(typer);
+ }
+
+ if (!is_msi_spi_valid(v2m->spi_start, v2m->nr_spis)) {
+ ret = -EINVAL;
+ goto err_out;
+ }
+
+ v2m->bm = kzalloc(sizeof(long) * BITS_TO_LONGS(v2m->nr_spis),
+ GFP_KERNEL);
+ if (!v2m->bm) {
+ pr_err("Failed to allocate MSI bitmap\n");
+ ret = -ENOMEM;
+ goto err_out;
+ }
+
+ spin_lock_init(&v2m->msi_cnt_lock);
+
+ pr_info("Node %s: range[%#lx:%#lx], SPI[%d:%d]\n", node->name,
+ (unsigned long)v2m->res.start, (unsigned long)v2m->res.end,
+ v2m->spi_start, (v2m->spi_start + v2m->nr_spis));
+
+ return 0;
+err_out:
+ of_pci_msi_chip_remove(&v2m->msi_chip);
+ if (v2m->base)
+ iounmap(v2m->base);
+ kfree(v2m);
+ return ret;
+}
+
+int __init gicv2m_of_init(struct device_node *node,
+ struct gic_chip_data *gic,
+ struct irq_chip *v2m_chip)
+{
+ int ret = 0;
+ struct v2m_data *v2m;
+ struct device_node *child = NULL;
+
+ INIT_LIST_HEAD(&gic->v2m_list);
+
+ v2m_chip->irq_mask = gicv2m_mask_irq;
+ v2m_chip->irq_unmask = gicv2m_unmask_irq;
+
+ for (;;) {
+ child = of_get_next_child(node, child);
+ if (!child)
+ break;
+
+ if (!of_device_is_compatible(child, "arm,gic-v2m-frame"))
+ continue;
+
+ if (!of_find_property(child, "msi-controller", NULL))
+ continue;
+
+ ret = gicv2m_init_one(child, &v2m, gic);
+ if (ret) {
+ of_node_put(node);
+ break;
+ }
+
+ list_add_tail(&v2m->list, &gic->v2m_list);
+ }
+
+ if (ret && list_empty(&gic->v2m_list)) {
+ pr_warn("Warning: Failed to enable GICv2m support.\n");
+ return -EINVAL;
+ }
+
+ return ret;
+}
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index dda6dbc..63fa02d 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -46,30 +46,9 @@
#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);

/*
@@ -131,15 +110,36 @@ 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 = v2mdat->gic;
+ } 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);
}

@@ -151,7 +151,7 @@ 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);

@@ -162,7 +162,7 @@ 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);

@@ -325,6 +325,15 @@ static struct irq_chip gic_chip = {
.irq_set_wake = gic_set_wake,
};

+static struct irq_chip v2m_chip = {
+ .name = "GICv2m",
+ .irq_eoi = gic_eoi_irq,
+ .irq_set_type = gic_set_type,
+#ifdef CONFIG_SMP
+ .irq_set_affinity = gic_set_affinity,
+#endif
+};
+
void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)
{
if (gic_nr >= MAX_GIC_NR)
@@ -767,19 +776,29 @@ 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;
+
+ irq_set_chip_data(irq, gic);
+
if (hw < 32) {
+ /* PPIs */
irq_set_percpu_devid(irq);
irq_set_chip_and_handler(irq, &gic_chip,
handle_percpu_devid_irq);
set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
} else {
- irq_set_chip_and_handler(irq, &gic_chip,
- handle_fasteoi_irq);
+ /* SPIs */
set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);

- gic_routable_irq_domain_ops->map(d, irq, hw);
+ if (!gicv2m_check_msi_range(gic, hw)) {
+ irq_set_chip_and_handler(irq, &gic_chip,
+ handle_fasteoi_irq);
+ gic_routable_irq_domain_ops->map(d, irq, hw);
+ } else {
+ irq_set_chip_and_handler(irq, &v2m_chip,
+ handle_fasteoi_irq);
+ }
}
- irq_set_chip_data(irq, d->host_data);
return 0;
}

@@ -1010,6 +1029,9 @@ gic_of_init(struct device_node *node, struct device_node *parent)
if (of_property_read_u32(node, "cpu-offset", &percpu_offset))
percpu_offset = 0;

+ if (IS_ENABLED(CONFIG_ARM_GIC_V2M))
+ gicv2m_of_init(node, &gic_data[gic_cnt], &v2m_chip);
+
gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset, node);
if (!gic_cnt)
gic_init_physaddr(node);
diff --git a/drivers/irqchip/irq-gic.h b/drivers/irqchip/irq-gic.h
new file mode 100644
index 0000000..3021665
--- /dev/null
+++ b/drivers/irqchip/irq-gic.h
@@ -0,0 +1,54 @@
+#ifndef _IRQ_GIC_H_
+#define _IRQ_GIC_H_
+
+#include <linux/msi.h>
+#include <linux/pci.h>
+
+union gic_base {
+ void __iomem *common_base;
+ void __percpu * __iomem *percpu_base;
+};
+
+struct gic_chip_data;
+
+struct v2m_data {
+#ifdef CONFIG_ARM_GIC_V2M
+ struct list_head list;
+ 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 */
+ struct gic_chip_data *gic;
+#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
+#ifdef CONFIG_ARM_GIC_V2M
+ struct list_head v2m_list;
+#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,
+ struct irq_chip *v2m_chip) __init;
+bool gicv2m_check_msi_range(struct gic_chip_data *gic, irq_hw_number_t hw);
+
+#endif /* _IRQ_GIC_H_ */
--
1.9.3