kexec: Consolidate machine_kexec_mask_interrupts() implementation

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 <farbere@amazon.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241204142003.32859-2-farbere@amazon.com

diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c
index 80ceb5bd2680bc253af2f8affe84d08231d1d4e6..dd430477e7c13910a5d8f97599971de7fd98ca4b 100644 (file)
--- 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 100570a048c5e8892c0112704f9ca74c4fc55b27..dcc3551cf6c2fc7257b46f0b6dde0eef602cc5e3 100644 (file)
--- 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 82e2203d86a31f830435f0d6b0bd31414ddda31f..6f121a0164a48b6e0a677ce9b9d667f12c7f177a 100644 (file)
--- 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 270ee93a0f7d83aaee81f1ac16dc3a8c6ae94027..601e569303e1bde77d14db0ff7baa73df55e2722 100644 (file)
--- 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 b8333a49ea5daa5a6e841af145287a7d046c965d..58a930a47422b65e21c7e22f48d7d6fde0f2166c 100644 (file)
--- 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 c95f96850c9e13350d80ebc4f85cc0b00ba3215e..deb28eb44f30f70095bb7df89b42bd273bab271e 100644 (file)
--- 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 3c830a6f7ef464ba2e10e3ffad6c53d0bae3c4ce..2306ce3e5f229ffe57faf04d457bdf58fcb423c9 100644 (file)
--- 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 fa711f80957b60157f38eceffa154b7b9469d3cd..25f51bf3c351f9652d39a9c4ff61ebe3e789e6ed 100644 (file)
--- 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 529adb1f58593c6b26fe28ca0d360bffeaef154c..875f25ed6f710aa002b7af7870cdc32fa06dd92b 100644 (file)
--- 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 f19d3080bf11aa7b2a27f773b4cff5d049561366..c0f44c06d69df4ea5b9843e67b8c64383092e7c0 100644 (file)
--- 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 (file)
index 0000000..0f9548c
--- /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);
+       }
+}