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| author | Benjamin Herrenschmidt | 2009-07-16 21:36:57 +0200 |
|---|---|---|
| committer | Benjamin Herrenschmidt | 2009-08-20 02:12:28 +0200 |
| commit | c5a8c0c99f67ae8a784faafbaaea1529825796e2 (patch) | |
| tree | 731b07d0ac0414dbeac5ce940fe59a04a8d63c3f /arch/powerpc/platforms/iseries/exception.S | |
| parent | powerpc: Use names rather than numbers for SPRGs (v2) (diff) | |
| download | kernel-qcow2-linux-c5a8c0c99f67ae8a784faafbaaea1529825796e2.tar.gz kernel-qcow2-linux-c5a8c0c99f67ae8a784faafbaaea1529825796e2.tar.xz kernel-qcow2-linux-c5a8c0c99f67ae8a784faafbaaea1529825796e2.zip | |
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/platforms/iseries/exception.S')
| -rw-r--r-- | arch/powerpc/platforms/iseries/exception.S | 37 |
1 files changed, 24 insertions, 13 deletions
diff --git a/arch/powerpc/platforms/iseries/exception.S b/arch/powerpc/platforms/iseries/exception.S index 2b8075979237..5369653dcf6a 100644 --- a/arch/powerpc/platforms/iseries/exception.S +++ b/arch/powerpc/platforms/iseries/exception.S @@ -128,25 +128,36 @@ iSeries_secondary_smp_loop: data_access_iSeries: 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_iSeries - 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_ISERIES_1 +FTR_SECTION_ELSE EXCEPTION_PROLOG_1(PACA_EXGEN) EXCEPTION_PROLOG_ISERIES_1 +ALT_FTR_SECTION_END_IFCLR(CPU_FTR_SLB) b data_access_common .do_stab_bolted_iSeries: - mtcrf 0x80,r12 - mfspr r12,SPRN_SPRG_SCRATCH1 - EXCEPTION_PROLOG_1(PACA_EXSLB) + 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_ISERIES_1 b .do_stab_bolted |