diff options
author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2020-11-25 08:10:52 +0100 |
---|---|---|
committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-12-03 15:01:32 +0100 |
commit | de1cd0790697e67b728de43e8657bb52f528bfb9 (patch) | |
tree | ab5eed22b35ceaacf8fa6816eec67f8492951c2c /arch/powerpc | |
parent | powerpc/32: Simplify EXCEPTION_PROLOG_1 macro (diff) | |
download | linux-de1cd0790697e67b728de43e8657bb52f528bfb9.tar.xz linux-de1cd0790697e67b728de43e8657bb52f528bfb9.zip |
powerpc/32s: Use SPRN_SPRG_SCRATCH2 in DSI prolog
Use SPRN_SPRG_SCRATCH2 as an alternative scratch register in
the early part of DSI prolog in order to avoid clobbering
SPRN_SPRG_SCRATCH0/1 used by other prologs.
The 603 doesn't like a jump from DataLoadTLBMiss to the 10 nops
that are now in the beginning of DSI exception as a result of
the feature section. To workaround this, add a jump as alternative.
It also avoids fetching 10 nops for nothing.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f9f8df2a2be93568768ef1ac793639f7914cf103.1606285014.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc')
-rw-r--r-- | arch/powerpc/include/asm/reg.h | 1 | ||||
-rw-r--r-- | arch/powerpc/kernel/head_book3s_32.S | 24 |
2 files changed, 9 insertions, 16 deletions
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index 0978a9a0a0d1..ee645e790446 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -1204,6 +1204,7 @@ #ifdef CONFIG_PPC_BOOK3S_32 #define SPRN_SPRG_SCRATCH0 SPRN_SPRG0 #define SPRN_SPRG_SCRATCH1 SPRN_SPRG1 +#define SPRN_SPRG_SCRATCH2 SPRN_SPRG2 #define SPRN_SPRG_603_LRU SPRN_SPRG4 #endif diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S index 8cc83ce61a2b..a93c75ca8c8e 100644 --- a/arch/powerpc/kernel/head_book3s_32.S +++ b/arch/powerpc/kernel/head_book3s_32.S @@ -288,9 +288,9 @@ MachineCheck: DO_KVM 0x300 DataAccess: #ifdef CONFIG_VMAP_STACK - mtspr SPRN_SPRG_SCRATCH0,r10 - mfspr r10, SPRN_SPRG_THREAD BEGIN_MMU_FTR_SECTION + mtspr SPRN_SPRG_SCRATCH2,r10 + mfspr r10, SPRN_SPRG_THREAD stw r11, THR11(r10) mfspr r10, SPRN_DSISR mfcr r11 @@ -304,19 +304,11 @@ BEGIN_MMU_FTR_SECTION .Lhash_page_dsi_cont: mtcr r11 lwz r11, THR11(r10) -END_MMU_FTR_SECTION_IFSET(MMU_FTR_HPTE_TABLE) - mtspr SPRN_SPRG_SCRATCH1,r11 - mfspr r11, SPRN_DAR - stw r11, DAR(r10) - mfspr r11, SPRN_DSISR - stw r11, DSISR(r10) - mfspr r11, SPRN_SRR0 - stw r11, SRR0(r10) - mfspr r11, SPRN_SRR1 /* check whether user or kernel */ - stw r11, SRR1(r10) - mfcr r10 - andi. r11, r11, MSR_PR - + mfspr r10, SPRN_SPRG_SCRATCH2 +MMU_FTR_SECTION_ELSE + b 1f +ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_HPTE_TABLE) +1: EXCEPTION_PROLOG_0 handle_dar_dsisr=1 EXCEPTION_PROLOG_1 b handle_page_fault_tramp_1 #else /* CONFIG_VMAP_STACK */ @@ -764,7 +756,7 @@ fast_hash_page_return: /* DSI */ mtcr r11 lwz r11, THR11(r10) - mfspr r10, SPRN_SPRG_SCRATCH0 + mfspr r10, SPRN_SPRG_SCRATCH2 rfi 1: /* ISI */ |