[PATCH v6 1/2] kexec: Consolidate machine_kexec_mask_interrupts() implementation
From: Eliav Farber <hidden>
Date: 2024-12-04 14:20:16
Also in:
linux-arm-kernel, linux-riscv, lkml
Subsystem:
arm port, arm64 port (aarch64 architecture), irq subsystem, linux for powerpc (32-bit and 64-bit), risc-v architecture, the rest · Maintainers:
Russell King, Catalin Marinas, Will Deacon, Thomas Gleixner, Madhavan Srinivasan, Michael Ellerman, Paul Walmsley, Palmer Dabbelt, Albert Ou, Linus Torvalds
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 <redacted> --- V5 -> V6: - Change GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD to not be user selectable. 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 | 6 +++++ kernel/irq/Makefile | 2 +- kernel/irq/kexec.c | 40 +++++++++++++++++++++++++++++++ 11 files changed, 52 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 100570a048c5..dcc3551cf6c2 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig@@ -149,6 +149,7 @@ 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 <asm/setup.h> #include <asm/firmware.h> -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 <linux/irq.h> #include <linux/kexec.h> #include <linux/mm.h> #include <linux/string.h>
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..875f25ed6f71 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig@@ -141,6 +141,12 @@ config GENERIC_IRQ_DEBUGFS If you don't know what to do here, say N. +# Clear forwarded VM interrupts during kexec. +# This option ensures the kernel clears active states for interrupts +# forwarded to virtual machines (VMs) during a machine kexec. +config GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD + bool + endmenu config GENERIC_IRQ_MULTI_HANDLER
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 <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/irqdesc.h> +#include <linux/irqnr.h> + +#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); + } +}
--
2.40.1