From: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx> ARM GICv2m specification extends GICv2 to support MSI(-X) with a new set of register frames. This patch introduces support for the non-secure GICv2m register frame. The driver currently matchs "arm,gic-400-plus" in device tree binding, which implements GICv2m. The "msi-controller" keyword in ARM GIC devicetree binding is used 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. MSI support is optional. 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); Cc: Mark Rutland <Mark.Rutland@xxxxxxx> Cc: Marc Zyngier <Marc.Zyngier@xxxxxxx> Cc: Jason Cooper <jason@xxxxxxxxxxxxxx> Cc: Catalin Marinas <Catalin.Marinas@xxxxxxx> Cc: Will Deacon <Will.Deacon@xxxxxxx> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx> --- Documentation/devicetree/bindings/arm/gic.txt | 19 +- drivers/irqchip/Kconfig | 6 + drivers/irqchip/Makefile | 1 + drivers/irqchip/irq-gic-v2m.c | 248 ++++++++++++++++++++++++++ drivers/irqchip/irq-gic-v2m.h | 13 ++ 5 files changed, 284 insertions(+), 3 deletions(-) create mode 100644 drivers/irqchip/irq-gic-v2m.c create mode 100644 drivers/irqchip/irq-gic-v2m.h diff --git a/Documentation/devicetree/bindings/arm/gic.txt b/Documentation/devicetree/bindings/arm/gic.txt index 5573c08..9e46f7f 100644 --- a/Documentation/devicetree/bindings/arm/gic.txt +++ b/Documentation/devicetree/bindings/arm/gic.txt @@ -12,11 +12,13 @@ Main node required properties: - compatible : should be one of: "arm,gic-400" + "arm,gic-400-plus" "arm,cortex-a15-gic" "arm,cortex-a9-gic" "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 +39,16 @@ 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 +64,10 @@ 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..795d704 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_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..c8a9ca9 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-$(CONFIG_ARM_GIC_V2M) += irq-gic-v2m.o obj-$(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/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c new file mode 100644 index 0000000..232a220 --- /dev/null +++ b/drivers/irqchip/irq-gic-v2m.c @@ -0,0 +1,248 @@ +/* + * 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/of_pci.h> +#include <linux/bitmap.h> + +#include "irqchip.h" +#include "irq-gic.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 + +/** + * 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 - 1; + + 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 (next >= size || 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 struct v2m_data *to_v2m_data(struct msi_chip *chip) +{ + struct gic_chip_data *gic = container_of(chip, struct gic_chip_data, + msi_chip); + return &gic->v2m_data; +} + +static void gicv2m_teardown_msi_irq(struct msi_chip *chip, unsigned int irq) +{ + int pos; + struct v2m_data *data = to_v2m_data(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 = to_v2m_data(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 + MSI_SETSPI_NS; + + msg.address_hi = (u32)(addr >> 32); + msg.address_lo = (u32)(addr); + msg.data = irq; +#ifdef CONFIG_PCI_MSI + write_msi_msg(irq, &msg); +#endif + + return 0; +} + +static int __init +gicv2m_msi_init(struct device_node *node, struct v2m_data *v2m) +{ + unsigned int val; + + if (of_address_to_resource(node, GIC_OF_MSIV2M_RANGE_INDEX, + &v2m->res)) { + pr_err("GICv2m: Failed locate GICv2m MSI register frame\n"); + return -EINVAL; + } + + v2m->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 = readl_relaxed(v2m->base + MSI_TYPER); + if (!val) { + pr_warn("GICv2m: Failed to read MSI_TYPER register\n"); + return -EINVAL; + } + + v2m->spi_start = (val >> 16) & 0x3ff; + v2m->nr_spis = val & 0x3ff; + + if (v2m->spi_start < GIC_V2M_MIN_SPI || + v2m->nr_spis >= GIC_V2M_MAX_SPI) { + pr_err("GICv2m: Init failed\n"); + return -EINVAL; + } + + v2m->bm = kzalloc(sizeof(long) * BITS_TO_LONGS(v2m->nr_spis), + GFP_KERNEL); + if (!v2m->bm) + 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)); + + 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 = { + .name = "GICv2m", + .irq_mask = gicv2m_mask_irq, + .irq_unmask = gicv2m_unmask_irq, + .irq_eoi = gic_eoi_irq, + .irq_set_type = gic_set_type, + .irq_retrigger = gic_retrigger, +#ifdef CONFIG_SMP + .irq_set_affinity = gic_set_affinity, +#endif +#ifdef CONFIG_PM + .irq_set_wake = gic_set_wake, +#endif +}; + +#ifdef CONFIG_OF +static int __init +gicv2m_of_init(struct device_node *node, struct device_node *parent) +{ + struct gic_chip_data *gic; + int ret; + + ret = _gic_of_init(node, parent, &gicv2m_chip, &gic); + if (ret) { + pr_err("GICv2m: Failed to initialize GIC\n"); + return ret; + } + +#ifdef CONFIG_PCI_MSI + gic->msi_chip.owner = THIS_MODULE; + gic->msi_chip.of_node = node; + gic->msi_chip.setup_irq = gicv2m_setup_msi_irq; + gic->msi_chip.teardown_irq = gicv2m_teardown_msi_irq; + ret = of_pci_msi_chip_add(&gic->msi_chip); + if (ret) { + /* MSI is optional and not supported here */ + pr_warn("GICv2m: MSI is not supported.\n"); + return 0; + } + + ret = gicv2m_msi_init(node, &gic->v2m_data); + if (ret) + return ret; +#endif + return ret; +} + +IRQCHIP_DECLARE(arm_gic_400_plus, "arm,gic-400-plus", gicv2m_of_init); + +#endif /* CONFIG_OF */ diff --git a/drivers/irqchip/irq-gic-v2m.h b/drivers/irqchip/irq-gic-v2m.h new file mode 100644 index 0000000..2d93a87 --- /dev/null +++ b/drivers/irqchip/irq-gic-v2m.h @@ -0,0 +1,13 @@ +#ifndef _IRQ_GIC_V2M_H_ +#define _IRQ_GIC_V2M_H_ + +struct v2m_data { + spinlock_t msi_cnt_lock; + 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 /*_IRQ_GIC_V2M_H_*/ -- 1.9.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html