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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-07-16 19:36:57 +0000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-08-20 10:12:28 +1000 |
| commit | c5a8c0c99f67ae8a784faafbaaea1529825796e2 (patch) | |
| tree | 731b07d0ac0414dbeac5ce940fe59a04a8d63c3f /arch/powerpc/kernel/exceptions-64s.S | |
| parent | ee43eb788b3a06425fffb912677e2e1c8b00dd3b (diff) | |
| download | kernel_samsung_smdk4412-c5a8c0c99f67ae8a784faafbaaea1529825796e2.zip kernel_samsung_smdk4412-c5a8c0c99f67ae8a784faafbaaea1529825796e2.tar.gz kernel_samsung_smdk4412-c5a8c0c99f67ae8a784faafbaaea1529825796e2.tar.bz2 | |
powerpc: Remove use of a second scratch SPRG in STAB code
The STAB code used on Power3 and RS/64 uses a second scratch SPRG to
save a GPR in order to decide whether to go to do_stab_bolted_* or
to handle a normal data access exception.
This prevents our scheme of freeing SPRG3 which is user visible for
user uses since we cannot use SPRG0 which, on RS/64, seems to be
read-only for supervisor mode (like POWER4).
This reworks the STAB exception entry to use the PACA as temporary
storage instead.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/exceptions-64s.S')
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 38 |
1 files changed, 25 insertions, 13 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 4e9640c..50f2ad3 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -50,18 +50,28 @@ data_access_pSeries: HMT_MEDIUM mtspr SPRN_SPRG_SCRATCH0,r13 BEGIN_FTR_SECTION - mtspr SPRN_SPRG_SCRATCH1,r12 - mfspr r13,SPRN_DAR - mfspr r12,SPRN_DSISR - srdi r13,r13,60 - rlwimi r13,r12,16,0x20 - mfcr r12 - cmpwi r13,0x2c + mfspr r13,SPRN_SPRG_PACA + std r9,PACA_EXSLB+EX_R9(r13) + std r10,PACA_EXSLB+EX_R10(r13) + mfspr r10,SPRN_DAR + mfspr r9,SPRN_DSISR + srdi r10,r10,60 + rlwimi r10,r9,16,0x20 + mfcr r9 + cmpwi r10,0x2c beq do_stab_bolted_pSeries - mtcrf 0x80,r12 - mfspr r12,SPRN_SPRG_SCRATCH1 -END_FTR_SECTION_IFCLR(CPU_FTR_SLB) + ld r10,PACA_EXSLB+EX_R10(r13) + std r11,PACA_EXGEN+EX_R11(r13) + ld r11,PACA_EXSLB+EX_R9(r13) + std r12,PACA_EXGEN+EX_R12(r13) + mfspr r12,SPRN_SPRG_SCRATCH0 + std r10,PACA_EXGEN+EX_R10(r13) + std r11,PACA_EXGEN+EX_R9(r13) + std r12,PACA_EXGEN+EX_R13(r13) + EXCEPTION_PROLOG_PSERIES_1(data_access_common) +FTR_SECTION_ELSE EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, data_access_common) +ALT_FTR_SECTION_END_IFCLR(CPU_FTR_SLB) . = 0x380 .globl data_access_slb_pSeries @@ -224,9 +234,11 @@ masked_interrupt: .align 7 do_stab_bolted_pSeries: - mtcrf 0x80,r12 - mfspr r12,SPRN_SPRG_SCRATCH1 - EXCEPTION_PROLOG_PSERIES(PACA_EXSLB, .do_stab_bolted) + std r11,PACA_EXSLB+EX_R11(r13) + std r12,PACA_EXSLB+EX_R12(r13) + mfspr r10,SPRN_SPRG_SCRATCH0 + std r10,PACA_EXSLB+EX_R13(r13) + EXCEPTION_PROLOG_PSERIES_1(.do_stab_bolted) #ifdef CONFIG_PPC_PSERIES /* |