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| author | Paul Mackerras <paulus@samba.org> | 2013-08-12 16:12:06 +1000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2013-08-14 15:00:09 +1000 |
| commit | 630573c1da54925290cf7a4f45752f3e9876d7e0 (patch) | |
| tree | bd571325f769cc30f1a4e111e837ddf934bfadcf | |
| parent | d82fbf305c63d309d122d86a0714d1e8c572ec1b (diff) | |
| download | linux-630573c1da54925290cf7a4f45752f3e9876d7e0.tar.bz2 | |
powerpc: Fix denormalized exception handler
The denormalized exception handler (denorm_exception_hv) has a couple
of bugs. If the CONFIG_PPC_DENORMALISATION option is not selected,
or the HSRR1_DENORM bit is not set in HSRR1, we don't test whether the
interrupt occurred within a KVM guest. On the other hand, if the
HSRR1_DENORM bit is set and CONFIG_PPC_DENORMALISATION is enabled,
we corrupt the CFAR and PPR.
To correct these problems, this replaces the open-coded version of
EXCEPTION_PROLOG_1 that is there currently, and that is missing the
saving of PPR and CFAR values to the PACA, with an instance of
EXCEPTION_PROLOG_1. This adds an explicit KVMTEST after testing
whether the exception is one we can handle, and adds code to restore
the CFAR on exit.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 4e00d223b2e3..2e00b268cfb7 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -367,11 +367,7 @@ denorm_exception_hv: HMT_MEDIUM_PPR_DISCARD mtspr SPRN_SPRG_HSCRATCH0,r13 EXCEPTION_PROLOG_0(PACA_EXGEN) - std r11,PACA_EXGEN+EX_R11(r13) - std r12,PACA_EXGEN+EX_R12(r13) - mfspr r9,SPRN_SPRG_HSCRATCH0 - std r9,PACA_EXGEN+EX_R13(r13) - mfcr r9 + EXCEPTION_PROLOG_1(PACA_EXGEN, NOTEST, 0x1500) #ifdef CONFIG_PPC_DENORMALISATION mfspr r10,SPRN_HSRR1 @@ -381,6 +377,7 @@ denorm_exception_hv: bne+ denorm_assist #endif + KVMTEST(0x1500) EXCEPTION_PROLOG_PSERIES_1(denorm_common, EXC_HV) KVM_HANDLER_SKIP(PACA_EXGEN, EXC_STD, 0x1500) @@ -501,6 +498,10 @@ denorm_done: mtcrf 0x80,r9 ld r9,PACA_EXGEN+EX_R9(r13) RESTORE_PPR_PACA(PACA_EXGEN, r10) +BEGIN_FTR_SECTION + ld r10,PACA_EXGEN+EX_CFAR(r13) + mtspr SPRN_CFAR,r10 +END_FTR_SECTION_IFSET(CPU_FTR_CFAR) ld r10,PACA_EXGEN+EX_R10(r13) ld r11,PACA_EXGEN+EX_R11(r13) ld r12,PACA_EXGEN+EX_R12(r13) |