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Sat, 30 Nov 2024 20:11:45 +0000 Received: from EX19MTAUEB002.ant.amazon.com (10.252.135.47) by EX19D013UWA004.ant.amazon.com (10.13.138.207) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1258.34; Sat, 30 Nov 2024 20:11:44 +0000 Received: from email-imr-corp-prod-pdx-all-2c-475d797d.us-west-2.amazon.com (10.124.125.2) by mail-relay.amazon.com (10.252.135.97) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1258.34 via Frontend Transport; Sat, 30 Nov 2024 20:11:44 +0000 Received: from dev-dsk-farbere-1a-46ecabed.eu-west-1.amazon.com (dev-dsk-farbere-1a-46ecabed.eu-west-1.amazon.com [172.19.116.181]) by email-imr-corp-prod-pdx-all-2c-475d797d.us-west-2.amazon.com (Postfix) with ESMTP id 0642CA0544; Sat, 30 Nov 2024 20:11:44 +0000 (UTC) Received: by dev-dsk-farbere-1a-46ecabed.eu-west-1.amazon.com (Postfix, from userid 14301484) id 924766F9F; Sat, 30 Nov 2024 20:11:43 +0000 (UTC) From: Eliav Farber To: , , , , , , , , , , , , , , , , , , , , , , , CC: Subject: [PATCH v5 1/2] kexec: Consolidate machine_kexec_mask_interrupts() implementation Date: Sat, 30 Nov 2024 20:11:42 +0000 Message-ID: <20241130201143.48808-2-farbere@amazon.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20241130201143.48808-1-farbere@amazon.com> References: <20241130201143.48808-1-farbere@amazon.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241130_121149_534345_B91927DF X-CRM114-Status: GOOD ( 27.16 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Consolidate the machine_kexec_mask_interrupts implementation into a common function located in a new file: kernel/irq/kexec.c. This removes duplicate implementations from architecture-specific files in arch/arm, arch/arm64, arch/powerpc, and arch/riscv, reducing code duplication and improving maintainability. The new implementation retains architecture-specific behavior for CONFIG_GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD, which was previously implemented for ARM64. When enabled (currently for ARM64), it clears the active state of interrupts forwarded to virtual machines (VMs) before handling other interrupt masking operations. Signed-off-by: Eliav Farber --- V4 -> V5: - The function machine_kexec_mask_interrupts() has been moved from kernel/kexec_core.c to a new file kernel/irq/kexec.c. - A new configuration option, GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD, has been added. - The parameters for the machine_kexec_mask_interrupts() function have been defined in reverse Christmas Tree style. - The comment explaining the call to irq_set_irqchip_state() has been improved for clarity. arch/arm/kernel/machine_kexec.c | 23 ------------------ arch/arm64/Kconfig | 1 + arch/arm64/kernel/machine_kexec.c | 31 ------------------------ arch/powerpc/include/asm/kexec.h | 1 - arch/powerpc/kexec/core.c | 22 ----------------- arch/powerpc/kexec/core_32.c | 1 + arch/riscv/kernel/machine_kexec.c | 23 ------------------ include/linux/irq.h | 3 +++ kernel/irq/Kconfig | 9 +++++++ kernel/irq/Makefile | 2 +- kernel/irq/kexec.c | 40 +++++++++++++++++++++++++++++++ 11 files changed, 55 insertions(+), 101 deletions(-) create mode 100644 kernel/irq/kexec.c diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c index 80ceb5bd2680..dd430477e7c1 100644 --- a/arch/arm/kernel/machine_kexec.c +++ b/arch/arm/kernel/machine_kexec.c @@ -127,29 +127,6 @@ void crash_smp_send_stop(void) cpus_stopped = 1; } -static void machine_kexec_mask_interrupts(void) -{ - unsigned int i; - struct irq_desc *desc; - - for_each_irq_desc(i, desc) { - struct irq_chip *chip; - - chip = irq_desc_get_chip(desc); - if (!chip) - continue; - - if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data)) - chip->irq_eoi(&desc->irq_data); - - if (chip->irq_mask) - chip->irq_mask(&desc->irq_data); - - if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) - chip->irq_disable(&desc->irq_data); - } -} - void machine_crash_shutdown(struct pt_regs *regs) { local_irq_disable(); diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index d743737bf9ce..359b9dcb35b9 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -150,6 +150,7 @@ config ARM64 select GENERIC_IDLE_POLL_SETUP select GENERIC_IOREMAP select GENERIC_IRQ_IPI + select GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD select GENERIC_IRQ_PROBE select GENERIC_IRQ_SHOW select GENERIC_IRQ_SHOW_LEVEL diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c index 82e2203d86a3..6f121a0164a4 100644 --- a/arch/arm64/kernel/machine_kexec.c +++ b/arch/arm64/kernel/machine_kexec.c @@ -207,37 +207,6 @@ void machine_kexec(struct kimage *kimage) BUG(); /* Should never get here. */ } -static void machine_kexec_mask_interrupts(void) -{ - unsigned int i; - struct irq_desc *desc; - - for_each_irq_desc(i, desc) { - struct irq_chip *chip; - int ret; - - chip = irq_desc_get_chip(desc); - if (!chip) - continue; - - /* - * First try to remove the active state. If this - * fails, try to EOI the interrupt. - */ - ret = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false); - - if (ret && irqd_irq_inprogress(&desc->irq_data) && - chip->irq_eoi) - chip->irq_eoi(&desc->irq_data); - - if (chip->irq_mask) - chip->irq_mask(&desc->irq_data); - - if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) - chip->irq_disable(&desc->irq_data); - } -} - /** * machine_crash_shutdown - shutdown non-crashing cpus and save registers */ diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h index 270ee93a0f7d..601e569303e1 100644 --- a/arch/powerpc/include/asm/kexec.h +++ b/arch/powerpc/include/asm/kexec.h @@ -61,7 +61,6 @@ struct pt_regs; extern void kexec_smp_wait(void); /* get and clear naca physid, wait for master to copy new code to 0 */ extern void default_machine_kexec(struct kimage *image); -extern void machine_kexec_mask_interrupts(void); void relocate_new_kernel(unsigned long indirection_page, unsigned long reboot_code_buffer, unsigned long start_address) __noreturn; diff --git a/arch/powerpc/kexec/core.c b/arch/powerpc/kexec/core.c index b8333a49ea5d..58a930a47422 100644 --- a/arch/powerpc/kexec/core.c +++ b/arch/powerpc/kexec/core.c @@ -22,28 +22,6 @@ #include #include -void machine_kexec_mask_interrupts(void) { - unsigned int i; - struct irq_desc *desc; - - for_each_irq_desc(i, desc) { - struct irq_chip *chip; - - chip = irq_desc_get_chip(desc); - if (!chip) - continue; - - if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data)) - chip->irq_eoi(&desc->irq_data); - - if (chip->irq_mask) - chip->irq_mask(&desc->irq_data); - - if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) - chip->irq_disable(&desc->irq_data); - } -} - #ifdef CONFIG_CRASH_DUMP void machine_crash_shutdown(struct pt_regs *regs) { diff --git a/arch/powerpc/kexec/core_32.c b/arch/powerpc/kexec/core_32.c index c95f96850c9e..deb28eb44f30 100644 --- a/arch/powerpc/kexec/core_32.c +++ b/arch/powerpc/kexec/core_32.c @@ -7,6 +7,7 @@ * Copyright (C) 2005 IBM Corporation. */ +#include #include #include #include diff --git a/arch/riscv/kernel/machine_kexec.c b/arch/riscv/kernel/machine_kexec.c index 3c830a6f7ef4..2306ce3e5f22 100644 --- a/arch/riscv/kernel/machine_kexec.c +++ b/arch/riscv/kernel/machine_kexec.c @@ -114,29 +114,6 @@ void machine_shutdown(void) #endif } -static void machine_kexec_mask_interrupts(void) -{ - unsigned int i; - struct irq_desc *desc; - - for_each_irq_desc(i, desc) { - struct irq_chip *chip; - - chip = irq_desc_get_chip(desc); - if (!chip) - continue; - - if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data)) - chip->irq_eoi(&desc->irq_data); - - if (chip->irq_mask) - chip->irq_mask(&desc->irq_data); - - if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) - chip->irq_disable(&desc->irq_data); - } -} - /* * machine_crash_shutdown - Prepare to kexec after a kernel crash * diff --git a/include/linux/irq.h b/include/linux/irq.h index fa711f80957b..25f51bf3c351 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -694,6 +694,9 @@ extern int irq_chip_request_resources_parent(struct irq_data *data); extern void irq_chip_release_resources_parent(struct irq_data *data); #endif +/* Disable or mask interrupts during a kernel kexec */ +extern void machine_kexec_mask_interrupts(void); + /* Handling of unhandled and spurious interrupts: */ extern void note_interrupt(struct irq_desc *desc, irqreturn_t action_ret); diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig index 529adb1f5859..5967accb8e87 100644 --- a/kernel/irq/Kconfig +++ b/kernel/irq/Kconfig @@ -154,3 +154,12 @@ config DEPRECATED_IRQ_CPU_ONOFFLINE bool depends on CAVIUM_OCTEON_SOC default CAVIUM_OCTEON_SOC + +config GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD + bool "Clear forwarded VM interrupts during kexec" + default n + help + When enabled, this option allows the kernel to clear the active state + of interrupts that are forwarded to virtual machines (VMs) during a + machine kexec. For interrupts that are not forwarded, if supported, + the kernel will attempt to trigger an End of Interrupt (EOI). diff --git a/kernel/irq/Makefile b/kernel/irq/Makefile index f19d3080bf11..c0f44c06d69d 100644 --- a/kernel/irq/Makefile +++ b/kernel/irq/Makefile @@ -1,6 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 -obj-y := irqdesc.o handle.o manage.o spurious.o resend.o chip.o dummychip.o devres.o +obj-y := irqdesc.o handle.o manage.o spurious.o resend.o chip.o dummychip.o devres.o kexec.o obj-$(CONFIG_IRQ_TIMINGS) += timings.o ifeq ($(CONFIG_TEST_IRQ_TIMINGS),y) CFLAGS_timings.o += -DDEBUG diff --git a/kernel/irq/kexec.c b/kernel/irq/kexec.c new file mode 100644 index 000000000000..0f9548c1708d --- /dev/null +++ b/kernel/irq/kexec.c @@ -0,0 +1,40 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include + +#include "internals.h" + +void machine_kexec_mask_interrupts(void) +{ + struct irq_desc *desc; + unsigned int i; + + for_each_irq_desc(i, desc) { + struct irq_chip *chip; + int check_eoi = 1; + + chip = irq_desc_get_chip(desc); + if (!chip) + continue; + + if (IS_ENABLED(CONFIG_GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD)) { + /* + * First try to remove the active state from an interrupt which is forwarded + * to a VM. If the interrupt is not forwarded, try to EOI the interrupt. + */ + check_eoi = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false); + } + + if (check_eoi && chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data)) + chip->irq_eoi(&desc->irq_data); + + if (chip->irq_mask) + chip->irq_mask(&desc->irq_data); + + if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) + chip->irq_disable(&desc->irq_data); + } +} From patchwork Sat Nov 30 20:11:43 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eliav Farber X-Patchwork-Id: 13889302 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2D641D7360D for ; Sat, 30 Nov 2024 20:14:55 +0000 (UTC) DKIM-Signature: v=1; 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Sat, 30 Nov 2024 20:11:43 +0000 (UTC) Received: by dev-dsk-farbere-1a-46ecabed.eu-west-1.amazon.com (Postfix, from userid 14301484) id 96751719D; Sat, 30 Nov 2024 20:11:43 +0000 (UTC) From: Eliav Farber To: , , , , , , , , , , , , , , , , , , , , , , , CC: Subject: [PATCH v5 2/2] kexec: Prevent redundant IRQ masking by checking state before shutdown Date: Sat, 30 Nov 2024 20:11:43 +0000 Message-ID: <20241130201143.48808-3-farbere@amazon.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20241130201143.48808-1-farbere@amazon.com> References: <20241130201143.48808-1-farbere@amazon.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241130_121155_111946_6951C894 X-CRM114-Status: GOOD ( 16.07 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org During machine kexec, the function machine_kexec_mask_interrupts() is responsible for disabling or masking all interrupts. While the irq_disable hook ensures that an already-disabled IRQ is not disabled again, the current implementation unconditionally invokes the irq_mask() function for every interrupt descriptor, even when the interrupt is already masked. A specific issue was observed in the crash kernel flow after unbinding a device (prior to kexec) that used a GPIO as an IRQ source. The warning was triggered by the gpiochip_disable_irq() function, which attempted to clear the FLAG_IRQ_IS_ENABLED flag when FLAG_USED_AS_IRQ was not set: ``` void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset) { struct gpio_desc *desc = gpiochip_get_desc(gc, offset); if (!IS_ERR(desc) && !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags); } ``` This issue surfaced after commit a8173820f441 ("gpio: gpiolib: Allow GPIO IRQs to lazy disable") introduced lazy disablement for GPIO IRQs. It replaced disable/enable hooks with mask/unmask hooks. Unlike the disable hook, the mask hook doesn't handle already-masked IRQs. When a GPIO-IRQ driver is unbound, the IRQ is released, triggering __irq_disable() and irq_state_set_masked(). A subsequent call to machine_kexec_mask_interrupts() re-invokes chip->irq_mask(). This results in a call chain, including gpiochip_irq_mask() and gpiochip_disable_irq(). Since FLAG_USED_AS_IRQ was cleared earlier, a warning occurs. Replace calls to irq_mask() and irq_disable() hooks with a simplified call to irq_shutdown(), and check if the interrupt is started (irqd_is_started) before calling the shutdown. Signed-off-by: Eliav Farber --- V4 -> V5: - The phrase 'This patch' has been removed from the commit message. kernel/irq/kexec.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/kernel/irq/kexec.c b/kernel/irq/kexec.c index 0f9548c1708d..1a3deffe6b5b 100644 --- a/kernel/irq/kexec.c +++ b/kernel/irq/kexec.c @@ -17,7 +17,7 @@ void machine_kexec_mask_interrupts(void) int check_eoi = 1; chip = irq_desc_get_chip(desc); - if (!chip) + if (!chip || !irqd_is_started(&desc->irq_data)) continue; if (IS_ENABLED(CONFIG_GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD)) { @@ -31,10 +31,6 @@ void machine_kexec_mask_interrupts(void) if (check_eoi && chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data)) chip->irq_eoi(&desc->irq_data); - if (chip->irq_mask) - chip->irq_mask(&desc->irq_data); - - if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data)) - chip->irq_disable(&desc->irq_data); + irq_shutdown(desc); } }