linux/drivers/irqchip
Will Deacon 39a06b67c2 irqchip/gic: Ensure we have an ISB between ack and ->handle_irq
Devices that expose their interrupt status registers via system
registers (e.g. Statistical profiling, CPU PMU, DynamIQ PMU, arch timer,
vgic (although unused by Linux), ...) rely on a context synchronising
operation on the CPU to ensure that the updated status register is
visible to the CPU when handling the interrupt. This usually happens as
a result of taking the IRQ exception in the first place, but there are
two race scenarios where this isn't the case.

For example, let's say we have two peripherals (X and Y), where Y uses a
system register for its interrupt status.

Case 1:
1. CPU takes an IRQ exception as a result of X raising an interrupt
2. Y then raises its interrupt line, but the update to its system
   register is not yet visible to the CPU
3. The GIC decides to expose Y's interrupt number first in the Ack
   register
4. The CPU runs the IRQ handler for Y, but the status register is stale

Case 2:
1. CPU takes an IRQ exception as a result of X raising an interrupt
2. CPU reads the interrupt number for X from the Ack register and runs
   its IRQ handler
3. Y raises its interrupt line and the Ack register is updated, but
   again, the update to its system register is not yet visible to the
   CPU.
4. Since the GIC drivers poll the Ack register, we read Y's interrupt
   number and run its handler without a context synchronisation
   operation, therefore seeing the stale register value.

In either case, we run the risk of missing an IRQ. This patch solves the
problem by ensuring that we execute an ISB in the GIC drivers prior
to invoking the interrupt handler. This is already the case for GICv3
and EOIMode 1 (the usual case for the host).

Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-08-02 16:55:59 +01:00
..
alphascale_asm9260-icoll.h irqchip/mxs: Add Alphascale ASM9260 support 2015-10-14 09:37:47 +02:00
exynos-combiner.c irqchip/exynos-combiner: Fix usage of __raw IO 2016-06-23 18:26:42 +00:00
irq-alpine-msi.c irqchip/irq-alpine-msi: Don't use <asm-generic/msi.h> 2016-05-11 10:12:25 +01:00
irq-armada-370-xp.c Revert "irqchip/armada-370-xp: Fix regression by clearing IRQ_NOAUTOEN" 2017-06-22 14:13:33 +01:00
irq-aspeed-i2c-ic.c irqchip/aspeed-i2c-ic: Add I2C IRQ controller for Aspeed 2017-06-22 14:15:00 +01:00
irq-aspeed-vic.c irqchip/aspeed-vic: Add AST2500 compatible string 2017-06-22 14:13:39 +01:00
irq-ath79-cpu.c irqchip/ath79-cpu: Move the CPU IRQ driver from arch/mips/ath79/ 2016-02-17 13:47:19 +00:00
irq-ath79-misc.c irqchip/ath79-misc: Move the MISC driver from arch/mips/ath79/ 2016-02-17 13:44:31 +00:00
irq-atmel-aic5.c irqchip/atmel-aic: Remove root argument from ->fixup() prototype 2017-07-04 11:10:37 +01:00
irq-atmel-aic-common.c irqchip/atmel-aic: Remove root argument from ->fixup() prototype 2017-07-04 11:10:37 +01:00
irq-atmel-aic-common.h irqchip/atmel-aic: Remove root argument from ->fixup() prototype 2017-07-04 11:10:37 +01:00
irq-atmel-aic.c irqchip/atmel-aic: Remove root argument from ->fixup() prototype 2017-07-04 11:10:37 +01:00
irq-bcm2835.c irqchip: bcm2835: Avoid arch/arm-specific handle_IRQ 2016-06-04 14:16:59 +00:00
irq-bcm2836.c cpu/hotplug: Cleanup state names 2016-12-25 10:47:44 +01:00
irq-bcm6345-l1.c treewide: remove redundant #include <linux/kconfig.h> 2016-10-11 15:06:33 -07:00
irq-bcm7038-l1.c irqchip/bcm7038-l1: Implement irq_cpu_offline() callback 2016-11-18 14:17:22 +01:00
irq-bcm7120-l2.c treewide: remove redundant #include <linux/kconfig.h> 2016-10-11 15:06:33 -07:00
irq-brcmstb-l2.c treewide: remove redundant #include <linux/kconfig.h> 2016-10-11 15:06:33 -07:00
irq-clps711x.c irqchip: clps711x: Changing the compatibility string to match with the smallest supported chip 2016-07-06 17:38:15 +02:00
irq-crossbar.c irqchip/irqdomain updates for 4.11-rc2 2017-03-09 12:06:41 +01:00
irq-digicolor.c irqchip: Prepare for local stub header removal 2015-07-11 23:14:23 +02:00
irq-dw-apb-ictl.c genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
irq-eznps.c irqchip/eznps: Drop pointless static qualifier in nps400_of_init() 2016-10-19 14:24:36 +02:00
irq-ftintc010.c irqchip/faraday: Replace moxa with ftintc010 2017-04-07 10:36:30 +01:00
irq-gic-common.c irqchip/gic: Prepare for adding platform driver 2016-06-13 11:53:52 +01:00
irq-gic-common.h irqchip/gic-v2: Parse and export virtual GIC information 2016-05-03 12:54:21 +02:00
irq-gic-pm.c irqchip/gic-pm: Update driver to use of_pm_clk_add_clk 2016-09-12 19:46:28 +01:00
irq-gic-realview.c irqchip/gic/realview: Support more RealView DCC variants 2016-03-09 09:38:05 +00:00
irq-gic-v2m.c iommu/dma: Add support for mapping MSIs 2016-09-16 09:34:22 +01:00
irq-gic-v3-its-pci-msi.c irqchip/gic-v3-its: Fix MSI alias accounting 2017-06-22 14:13:26 +01:00
irq-gic-v3-its-platform-msi.c irqchip/gic-v3-its-platform-msi: Make of_device_ids const 2017-06-23 09:14:58 +01:00
irq-gic-v3-its.c irqchip/gic-v3-its: Remove ACPICA version check for ACPI NUMA 2017-08-02 16:55:48 +01:00
irq-gic-v3.c irqchip/gic: Ensure we have an ISB between ack and ->handle_irq 2017-08-02 16:55:59 +01:00
irq-gic.c irqchip/gic: Ensure we have an ISB between ack and ->handle_irq 2017-08-02 16:55:59 +01:00
irq-hip04.c cpu/hotplug: Cleanup state names 2016-12-25 10:47:44 +01:00
irq-i8259.c irqchip/i8259: Constify irq_domain_ops 2017-06-22 14:12:49 +01:00
irq-imgpdc.c genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
irq-imx-gpcv2.c irqchip/irq-imx-gpcv2: Constify irq_domain_ops 2017-06-22 14:12:55 +01:00
irq-ingenic.c irqchip: Prepare for local stub header removal 2015-07-11 23:14:23 +02:00
irq-jcore-aic.c irqchip/jcore: Fix lost per-cpu interrupts 2016-10-14 14:26:55 +02:00
irq-keystone.c irqchip/keystone: Fix "scheduling while atomic" on rt 2016-12-31 18:41:45 +00:00
irq-lpc32xx.c irqchip: Add LPC32xx interrupt controller driver 2016-05-11 10:12:11 +01:00
irq-ls-scfg-msi.c irqchip: Add Layerscape SCFG MSI controller support 2016-05-04 09:58:04 +01:00
irq-mbigen.c irqchip/irq-mbigen: Constify irq_domain_ops 2017-06-22 14:13:00 +01:00
irq-metag-ext.c irqchip/metag-ext: Improve function-level documentation 2016-10-05 11:53:35 +02:00
irq-metag.c genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
irq-mips-cpu.c irqchip: mips-cpu: Introduce IPI IRQ domain support 2017-04-12 23:12:35 +02:00
irq-mips-gic.c irqchip/irq-mips-gic: Constify irq_domain_ops 2017-06-22 14:13:07 +01:00
irq-mmp.c irqchip: Kill off set_irq_flags usage 2015-09-16 16:53:38 +02:00
irq-mtk-cirq.c irqchip: Add Mediatek mtk-cirq driver 2017-04-07 10:52:22 +01:00
irq-mtk-sysirq.c irqchip/mtk-sysirq: Remove unnecessary barrier when configuring trigger 2017-04-07 10:52:17 +01:00
irq-mvebu-gicp.c irqchip/irq-mvebu-gicp: Allocate enough memory for spi_bitmap 2017-06-30 15:32:46 +01:00
irq-mvebu-gicp.h irqchip/irq-mvebu-gicp: Add new driver for Marvell GICP 2017-06-23 09:14:57 +01:00
irq-mvebu-icu.c irqchip/irq-mvebu-icu: Add new driver for Marvell ICU 2017-06-23 09:14:57 +01:00
irq-mvebu-odmi.c irqchip/gic: Return IRQ_SET_MASK_OK_DONE in the set_affinity method 2016-02-19 15:42:29 +00:00
irq-mvebu-pic.c irqchip/mvebu-pic: New driver for Marvell Armada 7K/8K PIC 2016-08-22 22:58:27 +00:00
irq-mxs.c irqchip/mxs: Enable SKIP_SET_WAKE and MASK_ON_SUSPEND 2016-12-31 19:06:44 +00:00
irq-nvic.c irqchip: Convert all alloc/xlate users from of_node to fwnode 2015-10-13 19:01:23 +02:00
irq-omap-intc.c irqchip/omap-intc: Fix missing <linux/irqchip/irq-omap-intc.h> include 2016-06-13 00:57:23 +00:00
irq-or1k-pic.c irqchip/or1k-pic: Fix interrupt acknowledgement 2017-06-30 15:33:11 +01:00
irq-orion.c genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
irq-partition-percpu.c irqchip: Add per-cpu interrupt partitioning library 2016-05-02 13:42:51 +02:00
irq-pic32-evic.c irqchip/irq-pic32-evic: Fix bug with external interrupts. 2016-06-02 18:03:50 +01:00
irq-renesas-h8s.c irqchip/irq-renesas-h8s: Constify irq_domain_ops 2017-06-22 14:13:20 +01:00
irq-renesas-h8300h.c irqchip/irq-renesas-h8300h: Constify irq_domain_ops 2017-06-22 14:13:14 +01:00
irq-renesas-intc-irqpin.c irqchip/renesas-intc-irqpin: Improve clock error handling and reporting 2015-11-24 16:54:19 +00:00
irq-renesas-irqc.c irqchip/renesas-irqc: Move over to nested generic chip 2015-09-29 20:41:00 +02:00
irq-s3c24xx.c irqchip/s3c24xx: Fixup IO accessors for big endian 2016-06-23 18:28:00 +00:00
irq-sa11x0.c ARM: kill off set_irq_flags usage 2015-07-28 13:58:13 +02:00
irq-sirfsoc.c irqchip/sirfsoc: Fix sparse warnings on __iomem 2016-06-13 00:48:31 +00:00
irq-st.c irqchip/st: Mark st_irq_syscfg_resume() __maybe_unused 2016-12-19 10:55:43 +01:00
irq-stm32-exti.c drivers/irqchip: Add STM32 external interrupts support 2016-09-21 14:13:21 +02:00
irq-sun4i.c irqchip/sun4i: Fix compilation outside of arch/arm 2016-02-02 15:46:40 +01:00
irq-sunxi-nmi.c irqchip/sunxi-nmi: Support sun6i-a31-r-intc compatible 2017-06-22 14:08:17 +01:00
irq-tango.c irqchip/tango: Add support for Sigma Designs SMP86xx/SMP87xx interrupt controller 2016-02-18 01:18:14 +00:00
irq-tb10x.c genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
irq-tegra.c irqchip/tegra: Fix sparse warnings on __iomem 2016-06-13 00:49:39 +00:00
irq-ts4800.c irqchip/ts4800: Make ts4800_ic_ops static const 2016-02-18 02:09:18 +00:00
irq-versatile-fpga.c irqchip: versatile-fpga: add new compatible for OX810SE SoC 2016-04-26 09:50:51 +02:00
irq-vf610-mscm-ir.c irqchip: Convert all alloc/xlate users from of_node to fwnode 2015-10-13 19:01:23 +02:00
irq-vic.c irqchip/vic: Improve function-level documentation 2016-10-05 11:53:35 +02:00
irq-vt8500.c irqchip: Kill off set_irq_flags usage 2015-09-16 16:53:38 +02:00
irq-xilinx-intc.c powerpc/virtex: Use generic xilinx irqchip driver 2016-11-29 09:14:50 +00:00
irq-xtensa-mx.c irqchip: Prepare for local stub header removal 2015-07-11 23:14:23 +02:00
irq-xtensa-pic.c irqchip: Prepare for local stub header removal 2015-07-11 23:14:23 +02:00
irq-zevio.c irqchip/zevio: Use irq_data_get_chip_type() helper 2015-12-30 18:29:02 +01:00
irqchip.c irqchip / GIC: Convert the GIC driver to ACPI probing 2015-10-01 02:18:38 +02:00
Kconfig irqchip/irq-mvebu-icu: Add new driver for Marvell ICU 2017-06-23 09:14:57 +01:00
Makefile irqchip/irq-mvebu-icu: Add new driver for Marvell ICU 2017-06-23 09:14:57 +01:00
qcom-irq-combiner.c irqchip/qcom: Use builtin_platform_driver to simplify the code 2017-06-22 14:15:00 +01:00
spear-shirq.c remove lots of IS_ERR_VALUE abuses 2016-05-27 15:26:11 -07:00