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-rw-r--r--arch/powerpc/kernel/entry_64.S62
1 files changed, 43 insertions, 19 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index bfbad08a1207..6f70ea821a07 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -210,27 +210,17 @@ system_call: /* label this so stack traces look sane */
andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
bne- syscall_exit_work
- andi. r0,r8,MSR_FP
- beq 2f
+ /* If MSR_FP and MSR_VEC are set in user msr, then no need to restore */
+ li r7,MSR_FP
#ifdef CONFIG_ALTIVEC
- andis. r0,r8,MSR_VEC@h
- bne 3f
+ oris r7,r7,MSR_VEC@h
#endif
-2: addi r3,r1,STACK_FRAME_OVERHEAD
-#ifdef CONFIG_PPC_BOOK3S
- li r10,MSR_RI
- mtmsrd r10,1 /* Restore RI */
-#endif
- bl restore_math
-#ifdef CONFIG_PPC_BOOK3S
- li r11,0
- mtmsrd r11,1
-#endif
- ld r8,_MSR(r1)
- ld r3,RESULT(r1)
- li r11,-MAX_ERRNO
+ and r0,r8,r7
+ cmpd r0,r7
+ bne syscall_restore_math
+.Lsyscall_restore_math_cont:
-3: cmpld r3,r11
+ cmpld r3,r11
ld r5,_CCR(r1)
bge- syscall_error
.Lsyscall_error_cont:
@@ -263,7 +253,41 @@ syscall_error:
neg r3,r3
std r5,_CCR(r1)
b .Lsyscall_error_cont
-
+
+syscall_restore_math:
+ /*
+ * Some initial tests from restore_math to avoid the heavyweight
+ * C code entry and MSR manipulations.
+ */
+ LOAD_REG_IMMEDIATE(r0, MSR_TS_MASK)
+ and. r0,r0,r8
+ bne 1f
+
+ ld r7,PACACURRENT(r13)
+ lbz r0,THREAD+THREAD_LOAD_FP(r7)
+#ifdef CONFIG_ALTIVEC
+ lbz r6,THREAD+THREAD_LOAD_VEC(r7)
+ add r0,r0,r6
+#endif
+ cmpdi r0,0
+ beq .Lsyscall_restore_math_cont
+
+1: addi r3,r1,STACK_FRAME_OVERHEAD
+#ifdef CONFIG_PPC_BOOK3S
+ li r10,MSR_RI
+ mtmsrd r10,1 /* Restore RI */
+#endif
+ bl restore_math
+#ifdef CONFIG_PPC_BOOK3S
+ li r11,0
+ mtmsrd r11,1
+#endif
+ /* Restore volatiles, reload MSR from updated one */
+ ld r8,_MSR(r1)
+ ld r3,RESULT(r1)
+ li r11,-MAX_ERRNO
+ b .Lsyscall_restore_math_cont
+
/* Traced system call support */
syscall_dotrace:
bl save_nvgprs