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Diffstat (limited to 'arch/x86/kernel/entry_64.S')
-rw-r--r--arch/x86/kernel/entry_64.S48
1 files changed, 45 insertions, 3 deletions
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index b86f332c96a..9b2aeaac9a6 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -627,6 +627,46 @@ END(stub_rt_sigreturn)
vector already pushed) */
#define XCPT_FRAME _frame ORIG_RAX
+/*
+ * Build the entry stubs and pointer table with some assembler magic.
+ * We pack 7 stubs into a single 32-byte chunk, which will fit in a
+ * single cache line on all modern x86 implementations.
+ */
+ .section .init.rodata,"a"
+ENTRY(interrupt)
+ .text
+ .p2align 5
+ .p2align CONFIG_X86_L1_CACHE_SHIFT
+ENTRY(irq_entries_start)
+ INTR_FRAME
+vector=FIRST_EXTERNAL_VECTOR
+.rept (NR_VECTORS-FIRST_EXTERNAL_VECTOR+6)/7
+ .balign 32
+ .rept 7
+ .if vector < NR_VECTORS
+ .if vector != FIRST_EXTERNAL_VECTOR
+ CFI_ADJUST_CFA_OFFSET -8
+ .endif
+1: pushq $(~vector+0x80) /* Note: always in signed byte range */
+ CFI_ADJUST_CFA_OFFSET 8
+ .if ((vector-FIRST_EXTERNAL_VECTOR)%7) != 6
+ jmp 2f
+ .endif
+ .previous
+ .quad 1b
+ .text
+vector=vector+1
+ .endif
+ .endr
+2: jmp common_interrupt
+.endr
+ CFI_ENDPROC
+END(irq_entries_start)
+
+.previous
+END(interrupt)
+.previous
+
/*
* Interrupt entry/exit.
*
@@ -635,11 +675,12 @@ END(stub_rt_sigreturn)
* Entry runs with interrupts off.
*/
-/* 0(%rsp): interrupt number */
+/* 0(%rsp): ~(interrupt number)+0x80 */
.macro interrupt func
+ addq $-0x80,(%rsp) /* Adjust vector to [-256,-1] range */
cld
SAVE_ARGS
- leaq -ARGOFFSET(%rsp),%rdi # arg1 for handler
+ leaq -ARGOFFSET(%rsp),%rdi /* arg1 for handler */
pushq %rbp
/*
* Save rbp twice: One is for marking the stack frame, as usual, and the
@@ -670,7 +711,8 @@ END(stub_rt_sigreturn)
call \func
.endm
-ENTRY(common_interrupt)
+ .p2align CONFIG_X86_L1_CACHE_SHIFT
+common_interrupt:
XCPT_FRAME
interrupt do_IRQ
/* 0(%rsp): oldrsp-ARGOFFSET */