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authorPaul Mackerras <paulus@samba.org>2006-10-18 10:11:22 +1000
committerPaul Mackerras <paulus@samba.org>2006-10-18 10:12:53 +1000
commitb0a779debd56514b2b5de7617a1643e5dac2d4dd (patch)
treee342bf44d34b8944da803efc690197988319fa4f /arch/powerpc/kernel/head_64.S
parent035223fb28791f0eb0d5719727355d3f6817d228 (diff)
[POWERPC] Make sure interrupt enable gets restored properly
The lazy IRQ disable patch missed a couple of places where the interrupt enable flags need to be restored correctly. First, we weren't restoring the paca->hard_enabled flag on interrupt exit. Instead of saving it on entry, we compute it from the MSR_EE bit in the MSR we are restoring at exit. Secondly, the MMU hash miss code was clearing both paca->soft_enabled and paca->hard_enabled but not restoring them in the case where hash_page was able to resolve the miss from the Linux page tables. Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/kernel/head_64.S')
-rw-r--r--arch/powerpc/kernel/head_64.S28
1 files changed, 19 insertions, 9 deletions
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index c93d9f35a121..d2890050b7e0 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -961,10 +961,18 @@ bad_stack:
* any task or sent any task a signal, you should use
* ret_from_except or ret_from_except_lite instead of this.
*/
+fast_exc_return_irq: /* restores irq state too */
+ ld r3,SOFTE(r1)
+ ld r12,_MSR(r1)
+ stb r3,PACASOFTIRQEN(r13) /* restore paca->soft_enabled */
+ rldicl r4,r12,49,63 /* get MSR_EE to LSB */
+ stb r4,PACAHARDIRQEN(r13) /* restore paca->hard_enabled */
+ b 1f
+
.globl fast_exception_return
fast_exception_return:
ld r12,_MSR(r1)
- ld r11,_NIP(r1)
+1: ld r11,_NIP(r1)
andi. r3,r12,MSR_RI /* check if RI is set */
beq- unrecov_fer
@@ -1361,6 +1369,16 @@ BEGIN_FW_FTR_SECTION
* interrupts if necessary.
*/
beq .ret_from_except_lite
+END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
+#endif
+BEGIN_FW_FTR_SECTION
+ /*
+ * Here we have interrupts hard-disabled, so it is sufficient
+ * to restore paca->{soft,hard}_enable and get out.
+ */
+ beq fast_exc_return_irq /* Return from exception on success */
+END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES)
+
/* For a hash failure, we don't bother re-enabling interrupts */
ble- 12f
@@ -1372,14 +1390,6 @@ BEGIN_FW_FTR_SECTION
ld r3,SOFTE(r1)
bl .local_irq_restore
b 11f
-END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
-#endif
-BEGIN_FW_FTR_SECTION
- beq fast_exception_return /* Return from exception on success */
- ble- 12f /* Failure return from hash_page */
-
- /* fall through */
-END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES)
/* Here we have a page fault that hash_page can't handle. */
_GLOBAL(handle_page_fault)