[V9 PATCH 2/2] irqchip: gicv2m: Add supports for ARM GICv2m MSI(-X)

From: suravee.suthikulpanit
Date: Fri Oct 31 2014 - 04:27:28 EST

From: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>

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@xxxxxxx>
Cc: Mark Rutland <Mark.Rutland@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Jason Cooper <jason@xxxxxxxxxxxxxx>
Cc: Will Deacon <Will.Deacon@xxxxxxx>
Cc: Catalin Marinas <Catalin.Marinas@xxxxxxx>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
---
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 | 395 ++++++++++++++++++++++++++
drivers/irqchip/irq-gic-v2m.h | 7 +
drivers/irqchip/irq-gic.c | 21 +-
7 files changed, 479 insertions(+), 4 deletions(-)

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 cde2f72..cbcde2d 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 2a48e0a..39ce065 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -8,6 +8,11 @@ config ARM_GIC
select IRQ_DOMAIN_HIERARCHY
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..d82b668
--- /dev/null
+++ b/drivers/irqchip/irq-gic-v2m.c
@@ -0,0 +1,395 @@
+/*
+ * 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@xxxxxxx>
+ * Harish Kasiviswanathan <harish.kasiviswanathan@xxxxxxx>
+ * Brandon Anderson <brandon.anderson@xxxxxxx>
+ *
+ * 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/irqdomain.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 <asm/hardirq.h>
+#include <asm/irq.h>
+
+#include "irqchip.h"
+#include "irq-gic-v2m.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)
+
+struct v2m_data {
+ 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 irq_domain *domain;
+};
+
+static struct irq_chip v2m_chip;
+
+/*
+ * 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);
+}
+
+static int gicv2m_setup_msi_irq(struct msi_chip *chip, struct pci_dev *pdev,
+ struct msi_desc *desc)
+{
+ int hwirq = 0, virq, avail;
+ struct v2m_data *v2m = 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(v2m, 1, &hwirq);
+ if (avail != 0) {
+ dev_err(&pdev->dev,
+ "MSI setup failed. Cannnot allocate IRQ\n");
+ return -ENOSPC;
+ }
+
+ virq = __irq_domain_alloc_irqs(v2m->domain, hwirq,
+ 1, NUMA_NO_NODE, v2m, true);
+ if (virq < 0)
+ return -EINVAL;
+
+ irq_domain_set_hwirq_and_chip(v2m->domain, virq, hwirq,
+ &v2m_chip, v2m);
+
+
+ irq_set_msi_desc(hwirq, desc);
+ irq_set_irq_type(hwirq, IRQ_TYPE_EDGE_RISING);
+
+ return 0;
+}
+
+static int gicv2m_domain_activate(struct irq_domain *domain,
+ struct irq_data *data)
+{
+ struct msi_msg msg;
+ struct v2m_data *v2m;
+ phys_addr_t addr;
+
+ v2m = container_of(data->chip_data, struct v2m_data, msi_chip);
+ addr = v2m->res.start + V2M_MSI_SETSPI_NS;
+
+ msg.address_hi = (u32)(addr >> 32);
+ msg.address_lo = (u32)(addr);
+ msg.data = data->irq;
+ write_msi_msg(data->irq, &msg);
+
+ return 0;
+}
+
+static int gicv2m_domain_deactivate(struct irq_domain *domain,
+ struct irq_data *data)
+{
+ struct msi_msg msg;
+
+ memset(&msg, 0, sizeof(msg));
+ write_msi_msg(data->irq, &msg);
+
+ return 0;
+}
+
+static int gicv2m_domain_alloc(struct irq_domain *d, unsigned int virq,
+ unsigned int nr_irqs, void *arg)
+{
+ int i, ret, irq;
+
+ for (i = 0; i < nr_irqs; i++) {
+ irq = virq + i;
+ set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
+ irq_set_chip_and_handler_name(irq, &v2m_chip,
+ handle_fasteoi_irq, v2m_chip.name);
+ }
+
+ ret = irq_domain_alloc_irqs_parent(d, virq, nr_irqs, NULL);
+ if (ret < 0)
+ pr_err("Failed to allocate parent IRQ domain\n");
+
+ return ret;
+}
+
+static void gicv2m_domain_free(struct irq_domain *d, unsigned int virq,
+ unsigned int nr_irqs)
+{
+ int i, irq;
+
+ for (i = 0; i < nr_irqs; i++) {
+ irq = virq + i;
+ irq_set_handler(irq, NULL);
+ irq_domain_set_hwirq_and_chip(d, irq, 0, NULL, NULL);
+ }
+
+ irq_domain_free_irqs_parent(d, virq, nr_irqs);
+}
+
+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 void gicv2m_mask_irq(struct irq_data *d)
+{
+ irq_chip_mask_parent(d);
+ if (d->msi_desc)
+ mask_msi_irq(d);
+}
+
+static void gicv2m_unmask_irq(struct irq_data *d)
+{
+ irq_chip_unmask_parent(d);
+ if (d->msi_desc)
+ unmask_msi_irq(d);
+}
+
+static struct irq_chip v2m_chip = {
+ .name = "GICv2m",
+ .irq_mask = gicv2m_mask_irq,
+ .irq_unmask = gicv2m_unmask_irq,
+ .irq_eoi = irq_chip_eoi_parent,
+ .irq_set_type = irq_chip_set_type_parent,
+
+#ifdef CONFIG_SMP
+ .irq_set_affinity = irq_chip_set_affinity_parent,
+#endif
+};
+
+static const struct irq_domain_ops gicv2m_domain_ops = {
+ .alloc = gicv2m_domain_alloc,
+ .free = gicv2m_domain_free,
+ .activate = gicv2m_domain_activate,
+ .deactivate = gicv2m_domain_deactivate,
+};
+
+static int __init
+gicv2m_init_one(struct device_node *node,
+ struct v2m_data **v,
+ struct irq_domain *parent)
+{
+ int ret;
+ struct v2m_data *v2m;
+
+ *v = kzalloc(sizeof(struct v2m_data), GFP_KERNEL);
+ if (!*v) {
+ pr_err("Failed to allocate struct v2m_data.\n");
+ return -ENOMEM;
+ }
+
+ v2m = *v;
+ 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;
+ }
+
+ v2m->domain = irq_domain_add_simple(node, v2m->nr_spis, v2m->spi_start,
+ &gicv2m_domain_ops, v2m);
+ if (!v2m->domain) {
+ pr_err("Failed to create GICv2m domain\n");
+ ret = -EINVAL;
+ goto err_out;
+ }
+
+ v2m->domain->parent = parent;
+
+ 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);
+ if (v2m->bm)
+ kzfree(v2m->bm);
+ kfree(v2m);
+ return ret;
+}
+
+int __init gicv2m_of_init(struct device_node *node,
+ struct irq_domain *parent,
+ struct list_head *v2m_list)
+{
+ int ret = 0;
+ struct v2m_data *v2m;
+ struct device_node *child = NULL;
+
+ INIT_LIST_HEAD(v2m_list);
+
+ 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, parent);
+ if (ret) {
+ of_node_put(node);
+ break;
+ }
+
+ list_add_tail(&v2m->list, v2m_list);
+ }
+
+ if (ret && list_empty(v2m_list)) {
+ pr_warn("Warning: Failed to enable GICv2m support.\n");
+ return -EINVAL;
+ }
+
+ return ret;
+}
diff --git a/drivers/irqchip/irq-gic-v2m.h b/drivers/irqchip/irq-gic-v2m.h
new file mode 100644
index 0000000..b5ae787
--- /dev/null
+++ b/drivers/irqchip/irq-gic-v2m.h
@@ -0,0 +1,7 @@
+#ifndef _IRQ_GIC_V2M_H_
+#define _IRQ_GIC_V2M_H_
+
+extern int gicv2m_of_init(struct device_node *node, struct irq_domain *parent,
+ struct list_head *v2m_list) __init;
+
+#endif /* _IRQ_GIC_V2M_H_ */
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index a99c211..4069eb3 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -46,6 +46,7 @@
#include <asm/smp_plat.h>

#include "irq-gic-common.h"
+#include "irq-gic-v2m.h"
#include "irqchip.h"

union gic_base {
@@ -68,6 +69,9 @@ struct gic_chip_data {
#ifdef CONFIG_GIC_NON_BANKED
void __iomem *(*get_base)(union gic_base *);
#endif
+#ifdef CONFIG_ARM_GIC_V2M
+ struct list_head v2m_list;
+#endif
};

static DEFINE_RAW_SPINLOCK(irq_controller_lock);
@@ -843,10 +847,14 @@ static int gic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
unsigned int type = IRQ_TYPE_NONE;
struct of_phandle_args *irq_data = arg;

- ret = gic_irq_domain_xlate(domain, irq_data->np, irq_data->args,
- irq_data->args_count, &hwirq, &type);
- if (ret)
- return ret;
+ if (irq_data) {
+ ret = gic_irq_domain_xlate(domain, irq_data->np, irq_data->args,
+ irq_data->args_count, &hwirq, &type);
+ if (ret)
+ return ret;
+ } else {
+ hwirq = virq;
+ }

for (i = 0; i < nr_irqs; i++)
gic_irq_domain_map(domain, virq+i, hwirq+i);
@@ -1055,6 +1063,11 @@ gic_of_init(struct device_node *node, struct device_node *parent)
irq = irq_of_parse_and_map(node, 0);
gic_cascade_irq(gic_cnt, irq);
}
+
+ if (IS_ENABLED(CONFIG_ARM_GIC_V2M))
+ gicv2m_of_init(node, gic_data[gic_cnt].domain,
+ &gic_data[gic_cnt].v2m_list);
+
gic_cnt++;
return 0;
}
--
1.9.3

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