[patch V2 31/44] x86/idt: Consolidate IDT invalidation

Thomas Gleixner
2017-08-25T22:02:49Z

[-- Attachment #1: x86-idt--Consolidate-idt-invalidation.patch --]
[-- Type: text/plain, Size: 2416 bytes --]

kexec and reboot have both code to invalidate IDT. Create a common function
and use it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/include/asm/desc.h | 3 +++
arch/x86/kernel/idt.c | 11 +++++++++++
arch/x86/kernel/machine_kexec_32.c | 14 +-------------
arch/x86/kernel/reboot.c | 4 +---
4 files changed, 16 insertions(+), 16 deletions(-)

--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -503,4 +503,7 @@ static inline void load_current_idt(void
else
load_idt((const struct desc_ptr *)&idt_descr);
}
+
+extern void idt_invalidate(void *addr);
+
#endif /* _ASM_X86_DESC_H */
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -24,3 +24,14 @@ const struct desc_ptr debug_idt_descr =
.address = (unsigned long) debug_idt_table,
};
#endif
+
+/**
+ * idt_invalidate - Invalidate interrupt descriptor table
+ * @addr: The virtual address of the 'invalid' IDT
+ */
+void idt_invalidate(void *addr)
+{
+ struct desc_ptr idt = { .address = (unsigned long) addr, .size = 0 };
+
+ load_idt(&idt);
+}
--- a/arch/x86/kernel/machine_kexec_32.c
+++ b/arch/x86/kernel/machine_kexec_32.c
@@ -26,18 +26,6 @@
#include <asm/set_memory.h>
#include <asm/debugreg.h>

-static void set_idt(void *newidt, __u16 limit)
-{
- struct desc_ptr curidt;
-
- /* ia32 supports unaliged loads & stores */
- curidt.size = limit;
- curidt.address = (unsigned long)newidt;
-
- load_idt(&curidt);
-}
-
-
static void set_gdt(void *newgdt, __u16 limit)
{
struct desc_ptr curgdt;
@@ -245,7 +233,7 @@ void machine_kexec(struct kimage *image)
* If you want to load them you must set up your own idt & gdt.
*/
set_gdt(phys_to_virt(0), 0);
- set_idt(phys_to_virt(0), 0);
+ idt_invalidate(phys_to_virt(0));

/* now call it */
image->start = relocate_kernel_ptr((unsigned long)image->head,
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -38,8 +38,6 @@
void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);

-static const struct desc_ptr no_idt = {};
-
/*
* This is set if we need to go through the 'emergency' path.
* When machine_emergency_restart() is called, we may be on
@@ -638,7 +636,7 @@ static void native_machine_emergency_res
break;

case BOOT_TRIPLE:
- load_idt(&no_idt);
+ idt_invalidate(NULL);
__asm__ __volatile__("int3");

/* We're probably dead after this, but... */