[PATCH 2/2] arm/gic: Add supports for GICv2m MSI(-X)
From: suravee.suthikulpanit
Date: Mon Jun 23 2014 - 20:33:30 EST
From: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
GICv2m extends GICv2 to support MSI(-X) with a new set of register frames.
This patch introduces support for the non-secure GICv2m register frame.
This is optional. It uses the "msi-controller" keyword in ARM GIC
devicetree binding to indentify GIC driver that it should enable MSI(-X)
support, The region of GICv2m MSI register frame is specified using the register
frame index 4 in the device tree.
Each GIC maintains an "msi_chip" structure. To discover the msi_chip,
PCI host driver can do the following:
struct device_node *gic_node = of_irq_find_parent(pdev->dev.of_node);
pcie_bus->msi_chip = of_pci_find_msi_chip_by_node(gic_node);
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
---
Documentation/devicetree/bindings/arm/gic.txt | 18 +-
drivers/irqchip/Kconfig | 6 +
drivers/irqchip/Makefile | 1 +
drivers/irqchip/gic-msi-v2m.c | 249 ++++++++++++++++++++++++++
drivers/irqchip/gic-msi-v2m.h | 20 +++
drivers/irqchip/irq-gic.c | 21 ++-
6 files changed, 311 insertions(+), 4 deletions(-)
create mode 100644 drivers/irqchip/gic-msi-v2m.c
create mode 100644 drivers/irqchip/gic-msi-v2m.h
diff --git a/Documentation/devicetree/bindings/arm/gic.txt b/Documentation/devicetree/bindings/arm/gic.txt
index 5573c08..ee4bc02 100644
--- a/Documentation/devicetree/bindings/arm/gic.txt
+++ b/Documentation/devicetree/bindings/arm/gic.txt
@@ -17,6 +17,7 @@ Main node required properties:
"arm,cortex-a7-gic"
"arm,arm11mp-gic"
- interrupt-controller : Identifies the node as an interrupt controller
+
- #interrupt-cells : Specifies the number of cells needed to encode an
interrupt source. The type shall be a <u32> and the value shall be 3.
@@ -37,9 +38,16 @@ Main node required properties:
the 8 possible cpus attached to the GIC. A bit set to '1' indicated
the interrupt is wired to that CPU. Only valid for PPI interrupts.
-- reg : Specifies base physical address(s) and size of the GIC registers. The
- first region is the GIC distributor register base and size. The 2nd region is
- the GIC cpu interface register base and size.
+- reg : Specifies base physical address(s) and size of the GIC register frames.
+
+ Region | Description
+ Index |
+ -------------------------------------------------------------------
+ 0 | GIC distributor register base and size
+ 1 | GIC cpu interface register base and size
+ 2 | VGIC interface control register base and size (Optional)
+ 3 | VGIC CPU interface register base and size (Optional)
+ 4 | GICv2m MSI interface register base and size (Optional)
Optional
- interrupts : Interrupt source of the parent interrupt controller on
@@ -55,6 +63,10 @@ Optional
by a crossbar/multiplexer preceding the GIC. The GIC irq
input line is assigned dynamically when the corresponding
peripheral's crossbar line is mapped.
+
+- msi-controller : Identifies the node as an MSI controller. This requires
+ the register region index 4.
+
Example:
intc: interrupt-controller@fff11000 {
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index bbb746e..a36bf94 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -7,6 +7,12 @@ config ARM_GIC
select IRQ_DOMAIN
select MULTI_IRQ_HANDLER
+config ARM_GIC_MSI_V2M
+ bool
+ select IRQ_DOMAIN
+ select MULTI_IRQ_HANDLER
+ depends on PCI && PCI_MSI
+
config GIC_NON_BANKED
bool
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 62a13e5..d43f904 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -16,6 +16,7 @@ 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
+obj-$(CONFIG_ARM_GIC_MSI_V2M) += gic-msi-v2m.o
obj-$(CONFIG_ARM_NVIC) += irq-nvic.o
obj-$(CONFIG_ARM_VIC) += irq-vic.o
obj-$(CONFIG_IMGPDC_IRQ) += irq-imgpdc.o
diff --git a/drivers/irqchip/gic-msi-v2m.c b/drivers/irqchip/gic-msi-v2m.c
new file mode 100644
index 0000000..e5c0f79
--- /dev/null
+++ b/drivers/irqchip/gic-msi-v2m.c
@@ -0,0 +1,249 @@
+/*
+ * ARM GIC v2m MSI 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 <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.
+ */
+
+#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/bitmap.h>
+
+#include "gic-msi-v2m.h"
+
+/* GICv2m MSI Registers */
+#define MSI_TYPER 0x008
+#define MSI_SETSPI_NS 0x040
+#define GIC_V2M_MIN_SPI 32
+#define GIC_V2M_MAX_SPI 1024
+#define GIC_OF_MSIV2M_RANGE_INDEX 4
+
+extern struct irq_chip gic_arch_extn;
+
+/**
+ * alloc_msi_irq - Allocate MSIs from avaialbe MSI bitmap.
+ * @data: Pointer to gicv2m_msi_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 avaiable. Otherwise return the number
+ * of avaiable interrupts. If none is avaiable, then returns -ENOENT.
+ */
+static int alloc_msi_irq(struct gicv2m_msi_data *data, int nvec, int *irq)
+{
+ int size = sizeof(unsigned long) * data->bm_sz;
+ int next = size, ret, num;
+
+ spin_lock(&data->msi_cnt_lock);
+
+ for (num = nvec; num > 0; num--) {
+ next = bitmap_find_next_zero_area(data->bm,
+ size, 0, num, 0);
+ if (next < size)
+ break;
+ }
+
+ if (next < size) {
+ bitmap_set(data->bm, next, nvec);
+ *irq = data->spi_start + next;
+ ret = 0;
+ } else if (num != 0) {
+ ret = num;
+ } else {
+ ret = -ENOENT;
+ }
+
+
+ spin_unlock(&data->msi_cnt_lock);
+
+ return ret;
+}
+
+static void free_msi_irq(struct gicv2m_msi_data *data, unsigned int irq)
+{
+ int pos;
+
+ spin_lock(&data->msi_cnt_lock);
+
+ pos = irq - data->spi_start;
+ if (pos >= 0 && pos < data->max_spi_cnt)
+ bitmap_clear(data->bm, pos, 1);
+
+ spin_unlock(&data->msi_cnt_lock);
+}
+
+static inline struct gicv2m_msi_data *to_gicv2m_msi_data(struct msi_chip *chip)
+{
+ return container_of(chip, struct gicv2m_msi_data, chip);
+}
+
+static void gicv2m_teardown_msi_irq(struct msi_chip *chip, unsigned int irq)
+{
+ free_msi_irq(to_gicv2m_msi_data(chip), irq);
+}
+
+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 gicv2m_msi_data *data = to_gicv2m_msi_data(chip);
+
+ if (data == NULL) {
+ dev_err(&pdev->dev,
+ "GICv2m: MSI setup failed. Invalid platform data\n");
+ return -EINVAL;
+ }
+
+ 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_msi_desc(irq, desc);
+ irq_set_irq_type(irq, IRQ_TYPE_EDGE_RISING);
+
+ addr = (unsigned long)(data->paddr64 + MSI_SETSPI_NS);
+
+ msg.address_hi = (unsigned int)(addr >> 32);
+ msg.address_lo = (unsigned int)(addr);
+ msg.data = irq;
+#ifdef CONFIG_PCI_MSI
+ write_msi_msg(irq, &msg);
+#endif
+
+ return 0;
+}
+
+static void gicv2m_mask_msi(struct irq_data *d)
+{
+ if (d->msi_desc)
+ mask_msi_irq(d);
+}
+
+static void gicv2m_unmask_msi(struct irq_data *d)
+{
+ if (d->msi_desc)
+ unmask_msi_irq(d);
+}
+
+int __init gicv2m_msi_init(struct device_node *node,
+ struct gicv2m_msi_data *msi)
+{
+ unsigned int val;
+ const __be32 *msi_be;
+
+ msi_be = of_get_address(node, GIC_OF_MSIV2M_RANGE_INDEX, NULL, NULL);
+ if (!msi_be) {
+ pr_err("GICv2m failed. Fail to locate MSI base.\n");
+ return -EINVAL;
+ }
+
+ msi->paddr64 = of_translate_address(node, msi_be);
+ msi->base = of_iomap(node, GIC_OF_MSIV2M_RANGE_INDEX);
+
+ /*
+ * MSI_TYPER:
+ * [31:26] Reserved
+ * [25:16] lowest SPI assigned to MSI
+ * [15:10] Reserved
+ * [9:0] Numer of SPIs assigned to MSI
+ */
+ val = __raw_readl(msi->base + MSI_TYPER);
+ if (!val) {
+ pr_warn("GICv2m: Failed to read MSI_TYPER register\n");
+ return -EINVAL;
+ }
+
+ msi->spi_start = (val >> 16) & 0x3ff;
+ msi->max_spi_cnt = val & 0x3ff;
+
+ pr_debug("GICv2m: SPI = %u, cnt = %u\n",
+ msi->spi_start, msi->max_spi_cnt);
+
+ if (msi->spi_start < GIC_V2M_MIN_SPI ||
+ msi->max_spi_cnt >= GIC_V2M_MAX_SPI) {
+ pr_err("GICv2m: Init failed\n");
+ return -EINVAL;
+ }
+
+ msi->bm_sz = BITS_TO_LONGS(msi->max_spi_cnt);
+ msi->bm = kzalloc(msi->bm_sz, GFP_KERNEL);
+ if (!msi->bm)
+ return -ENOMEM;
+
+ spin_lock_init(&msi->msi_cnt_lock);
+
+ msi->chip.owner = THIS_MODULE;
+ msi->chip.of_node = node;
+ msi->chip.setup_irq = gicv2m_setup_msi_irq;
+ msi->chip.teardown_irq = gicv2m_teardown_msi_irq;
+
+ pr_info("GICv2m: SPI range [%d:%d]\n",
+ msi->spi_start, (msi->spi_start + msi->max_spi_cnt));
+
+ gic_arch_extn.irq_mask = gicv2m_mask_msi;
+ gic_arch_extn.irq_unmask = gicv2m_unmask_msi;
+
+ return 0;
+}
+EXPORT_SYMBOL(gicv2m_msi_init);
+
+
+
+/**
+ * Override arch_setup_msi_irq in drivers/pci/msi.c
+ * since we don't want to change the chip_data
+ */
+int arch_setup_msi_irq(struct pci_dev *pdev, struct msi_desc *desc)
+{
+ struct msi_chip *chip = pdev->bus->msi;
+
+ if (!chip || !chip->setup_irq)
+ return -EINVAL;
+
+ return chip->setup_irq(chip, pdev, desc);
+}
+
+/**
+ * Override arch_teardown_msi_irq in drivers/pci/msi.c
+ */
+void arch_teardown_msi_irq(unsigned int irq)
+{
+ struct msi_desc *desc;
+ struct msi_chip *chip;
+
+ desc = irq_get_msi_desc(irq);
+ if (!desc)
+ return;
+
+ chip = desc->dev->bus->msi;
+ if (!chip)
+ return;
+
+ chip->teardown_irq(chip, irq);
+}
diff --git a/drivers/irqchip/gic-msi-v2m.h b/drivers/irqchip/gic-msi-v2m.h
new file mode 100644
index 0000000..164d929
--- /dev/null
+++ b/drivers/irqchip/gic-msi-v2m.h
@@ -0,0 +1,20 @@
+#ifndef GIC_MSI_V2M_H
+#define GIC_MSI_V2M_H
+
+#include <linux/msi.h>
+
+struct gicv2m_msi_data {
+ struct msi_chip chip;
+ spinlock_t msi_cnt_lock;
+ u64 paddr64; /* GICv2m phys address */
+ void __iomem *base; /* GICv2m virt address */
+ unsigned int spi_start; /* The SPI number that MSIs start */
+ unsigned int max_spi_cnt; /* The number of SPIs for MSIs */
+ unsigned long *bm; /* MSI vector bitmap */
+ unsigned long bm_sz; /* MSI bitmap size */
+};
+
+extern int gicv2m_msi_init(struct device_node *node,
+ struct gicv2m_msi_data *msi) __init;
+
+#endif /*GIC_MSI_V2M_H*/
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index adc86de..dcff99b 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -35,6 +35,7 @@
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
+#include <linux/of_pci.h>
#include <linux/irqdomain.h>
#include <linux/interrupt.h>
#include <linux/percpu.h>
@@ -48,6 +49,10 @@
#include "irqchip.h"
+#ifdef CONFIG_ARM_GIC_MSI_V2M
+#include "gic-msi-v2m.h"
+#endif
+
union gic_base {
void __iomem *common_base;
void __percpu * __iomem *percpu_base;
@@ -68,6 +73,9 @@ struct gic_chip_data {
#ifdef CONFIG_GIC_NON_BANKED
void __iomem *(*get_base)(union gic_base *);
#endif
+#ifdef CONFIG_ARM_GIC_MSI_V2M
+ struct gicv2m_msi_data msi_data;
+#endif
};
static DEFINE_RAW_SPINLOCK(irq_controller_lock);
@@ -246,7 +254,8 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
bool force)
{
void __iomem *reg = gic_dist_base(d) + GIC_DIST_TARGET + (gic_irq(d) & ~3);
- unsigned int cpu, shift = (gic_irq(d) % 4) * 8;
+ unsigned int shift = (gic_irq(d) % 4) * 8;
+ unsigned int cpu = cpumask_any_and(mask_val, cpu_online_mask);
u32 val, mask, bit;
if (!force)
@@ -1047,6 +1056,7 @@ gic_of_init(struct device_node *node, struct device_node *parent)
void __iomem *dist_base;
u32 percpu_offset;
int irq;
+ struct gic_chip_data *gic;
if (WARN_ON(!node))
return -ENODEV;
@@ -1068,6 +1078,15 @@ 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);
}
+
+#ifdef CONFIG_ARM_GIC_MSI_V2M
+ if (of_find_property(node, "msi-controller", NULL)) {
+ gic = &gic_data[gic_cnt];
+ if (!gicv2m_msi_init(node, &gic->msi_data))
+ of_pci_msi_chip_add(&gic->msi_data.chip);
+ }
+#endif
+
gic_cnt++;
return 0;
}
--
1.9.0
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