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path: root/arch/x86/xen/xen-asm_32.S
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Diffstat (limited to 'arch/x86/xen/xen-asm_32.S')
-rw-r--r--arch/x86/xen/xen-asm_32.S45
1 files changed, 27 insertions, 18 deletions
diff --git a/arch/x86/xen/xen-asm_32.S b/arch/x86/xen/xen-asm_32.S
index 22a2093b586..fd92a64d748 100644
--- a/arch/x86/xen/xen-asm_32.S
+++ b/arch/x86/xen/xen-asm_32.S
@@ -14,6 +14,7 @@
#include <asm/thread_info.h>
#include <asm/processor-flags.h>
#include <asm/segment.h>
+#include <asm/asm.h>
#include <xen/interface/xen.h>
@@ -74,6 +75,17 @@ ENDPROC(xen_sysexit)
* stack state in whatever form its in, we keep things simple by only
* using a single register which is pushed/popped on the stack.
*/
+
+.macro POP_FS
+1:
+ popw %fs
+.pushsection .fixup, "ax"
+2: movw $0, (%esp)
+ jmp 1b
+.popsection
+ _ASM_EXTABLE(1b,2b)
+.endm
+
ENTRY(xen_iret)
/* test eflags for special cases */
testl $(X86_EFLAGS_VM | XEN_EFLAGS_NMI), 8(%esp)
@@ -82,17 +94,15 @@ ENTRY(xen_iret)
push %eax
ESP_OFFSET=4 # bytes pushed onto stack
- /*
- * Store vcpu_info pointer for easy access. Do it this way to
- * avoid having to reload %fs
- */
+ /* Store vcpu_info pointer for easy access */
#ifdef CONFIG_SMP
- GET_THREAD_INFO(%eax)
- movl TI_cpu(%eax), %eax
- movl __per_cpu_offset(,%eax,4), %eax
- mov xen_vcpu(%eax), %eax
+ pushw %fs
+ movl $(__KERNEL_PERCPU), %eax
+ movl %eax, %fs
+ movl %fs:xen_vcpu, %eax
+ POP_FS
#else
- movl xen_vcpu, %eax
+ movl %ss:xen_vcpu, %eax
#endif
/* check IF state we're restoring */
@@ -105,19 +115,21 @@ ENTRY(xen_iret)
* resuming the code, so we don't have to be worried about
* being preempted to another CPU.
*/
- setz XEN_vcpu_info_mask(%eax)
+ setz %ss:XEN_vcpu_info_mask(%eax)
xen_iret_start_crit:
/* check for unmasked and pending */
- cmpw $0x0001, XEN_vcpu_info_pending(%eax)
+ cmpw $0x0001, %ss:XEN_vcpu_info_pending(%eax)
/*
* If there's something pending, mask events again so we can
- * jump back into xen_hypervisor_callback
+ * jump back into xen_hypervisor_callback. Otherwise do not
+ * touch XEN_vcpu_info_mask.
*/
- sete XEN_vcpu_info_mask(%eax)
+ jne 1f
+ movb $1, %ss:XEN_vcpu_info_mask(%eax)
- popl %eax
+1: popl %eax
/*
* From this point on the registers are restored and the stack
@@ -135,10 +147,7 @@ iret_restore_end:
1: iret
xen_iret_end_crit:
-.section __ex_table, "a"
- .align 4
- .long 1b, iret_exc
-.previous
+ _ASM_EXTABLE(1b, iret_exc)
hyper_iret:
/* put this out of line since its very rarely used */