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authorH. Peter Anvin <hpa@zytor.com>2012-04-18 17:16:48 -0700
committerH. Peter Anvin <hpa@linux.intel.com>2012-04-19 15:07:56 -0700
commitffc4bc9c6fa4eaf935d96d139bfa7443cac0b88e (patch)
tree61296184c680a012f7d4a10deedec2caba87dc53
parent84f4fc524eed040660bd4ebc8cba259d8afe8461 (diff)
x86, paravirt: Replace GET_CR2_INTO_RCX with GET_CR2_INTO_RAX
GET_CR2_INTO_RCX is asinine: it is only used in one place, the actual paravirt call returns the value in %rax, not %rcx; and the one place that wants it wants the result in %r9. We actually generate as a result of this call: call ... movq %rax, %rcx xorq %rax, %rax /* this value isn't even used... */ movq %rcx, %r9 At least make the macro do what the paravirt call does, which is put the value into %rax. Nevermind the fact that the macro clobbers all the volatile registers. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/r/1334794610-5546-4-git-send-email-hpa@zytor.com Cc: Glauber de Oliveira Costa <glommer@parallels.com>
-rw-r--r--arch/x86/include/asm/paravirt.h6
-rw-r--r--arch/x86/kernel/head_64.S6
2 files changed, 5 insertions, 7 deletions
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index aa0f9130836..6cbbabf5270 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -1023,10 +1023,8 @@ extern void default_banner(void);
call PARA_INDIRECT(pv_cpu_ops+PV_CPU_swapgs) \
)
-#define GET_CR2_INTO_RCX \
- call PARA_INDIRECT(pv_mmu_ops+PV_MMU_read_cr2); \
- movq %rax, %rcx; \
- xorq %rax, %rax;
+#define GET_CR2_INTO_RAX \
+ call PARA_INDIRECT(pv_mmu_ops+PV_MMU_read_cr2)
#define PARAVIRT_ADJUST_EXCEPTION_FRAME \
PARA_SITE(PARA_PATCH(pv_irq_ops, PV_IRQ_adjust_exception_frame), \
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index adf52e85d55..d1e112c8b57 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -23,8 +23,9 @@
#ifdef CONFIG_PARAVIRT
#include <asm/asm-offsets.h>
#include <asm/paravirt.h>
+#define GET_CR2_INTO(reg) GET_CR2_INTO_RAX ; movq %rax, reg
#else
-#define GET_CR2_INTO_RCX movq %cr2, %rcx
+#define GET_CR2_INTO(reg) movq %cr2, reg
#endif
/* we are not able to switch in one step to the final KERNEL ADDRESS SPACE
@@ -286,8 +287,7 @@ ENTRY(early_idt_handler)
cmpl $2,early_recursion_flag(%rip)
jz 1f
incl early_recursion_flag(%rip)
- GET_CR2_INTO_RCX
- movq %rcx,%r9
+ GET_CR2_INTO(%r9)
xorl %r8d,%r8d # zero for error code
movl %esi,%ecx # get vector number
# Test %ecx against mask of vectors that push error code.