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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2019-02-21 10:37:54 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-02-22 00:10:16 +1100 |
| commit | 0df977eafc792a5365a7f81d8d5920132e03afad (patch) | |
| tree | 145c1adc8829075f35bbf51742de3a4430259f0f /arch/powerpc/kernel/entry_32.S | |
| parent | 40058337f23f79212f92ed5ef066e90a032905b1 (diff) | |
| download | lwn-0df977eafc792a5365a7f81d8d5920132e03afad.tar.gz lwn-0df977eafc792a5365a7f81d8d5920132e03afad.zip | |
powerpc/6xx: Don't use SPRN_SPRG2 for storing stack pointer while in RTAS
When calling RTAS, the stack pointer is stored in SPRN_SPRG2
in order to be able to restore it in case of machine check in RTAS.
As machine check is not a perfomance critical path, this patch
frees SPRN_SPRG2 by using a field in thread struct instead.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/entry_32.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_32.S | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index c2b66fbbf7f0..6c671ceb5a06 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -1332,7 +1332,7 @@ _GLOBAL(enter_rtas) MTMSRD(r0) /* don't get trashed */ li r9,MSR_KERNEL & ~(MSR_IR|MSR_DR) mtlr r6 - mtspr SPRN_SPRG_RTAS,r7 + stw r7, THREAD + RTAS_SP(r2) mtspr SPRN_SRR0,r8 mtspr SPRN_SRR1,r9 RFI @@ -1341,7 +1341,8 @@ _GLOBAL(enter_rtas) lwz r9,8(r9) /* original msr value */ addi r1,r1,INT_FRAME_SIZE li r0,0 - mtspr SPRN_SPRG_RTAS,r0 + tophys(r7, r2) + stw r0, THREAD + RTAS_SP(r7) mtspr SPRN_SRR0,r8 mtspr SPRN_SRR1,r9 RFI /* return to caller */ |