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| author | Paul Mackerras <paulus@samba.org> | 2006-10-18 10:11:22 +1000 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2006-10-18 10:12:53 +1000 |
| commit | b0a779debd56514b2b5de7617a1643e5dac2d4dd (patch) | |
| tree | e342bf44d34b8944da803efc690197988319fa4f /arch/powerpc/kernel/head_64.S | |
| parent | 035223fb28791f0eb0d5719727355d3f6817d228 (diff) | |
| download | linux-b0a779debd56514b2b5de7617a1643e5dac2d4dd.tar.gz linux-b0a779debd56514b2b5de7617a1643e5dac2d4dd.tar.bz2 linux-b0a779debd56514b2b5de7617a1643e5dac2d4dd.zip | |
[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.S | 28 |
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) |