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| author |   Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-07-23 23:15:07 +0000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-08-20 10:12:36 +1000 |
| commit | 6c1719942e19936044c4673b18afa26e45a02320 (patch) | |
| tree | d235739a709ecf4f36d28ad34b80f8930ef525b1 /arch/powerpc | |
| parent | powerpc/mm: Fix misplaced #endif in pgtable-ppc64-64k.h (diff) | |
| download | linux-dev-6c1719942e19936044c4673b18afa26e45a02320.tar.xz linux-dev-6c1719942e19936044c4673b18afa26e45a02320.zip | |
powerpc/of: Remove useless register save/restore when calling OF back
enter_prom() used to save and restore registers such as CTR, XER etc..
which are volatile, or SRR0,1... which we don't care about. This
removes a bunch of useless code and while at it turns an mtmsrd into
an MTMSRD macro which will be useful to Book3E.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 38 |
1 files changed, 6 insertions, 32 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index dbf0e3115611..1cb0f3d1714b 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -823,30 +823,17 @@ _GLOBAL(enter_prom) * of all registers that it saves. We therefore save those registers * PROM might touch to the stack. (r0, r3-r13 are caller saved) */ - SAVE_8GPRS(2, r1) + SAVE_GPR(2, r1) SAVE_GPR(13, r1) SAVE_8GPRS(14, r1) SAVE_10GPRS(22, r1) - mfcr r4 - std r4,_CCR(r1) - mfctr r5 - std r5,_CTR(r1) - mfspr r6,SPRN_XER - std r6,_XER(r1) - mfdar r7 - std r7,_DAR(r1) - mfdsisr r8 - std r8,_DSISR(r1) - mfsrr0 r9 - std r9,_SRR0(r1) - mfsrr1 r10 - std r10,_SRR1(r1) + mfcr r10 mfmsr r11 + std r10,_CCR(r1) std r11,_MSR(r1) /* Get the PROM entrypoint */ - ld r0,GPR4(r1) - mtlr r0 + mtlr r4 /* Switch MSR to 32 bits mode */ @@ -860,8 +847,7 @@ _GLOBAL(enter_prom) mtmsrd r11 isync - /* Restore arguments & enter PROM here... */ - ld r3,GPR3(r1) + /* Enter PROM here... */ blrl /* Just make sure that r1 top 32 bits didn't get @@ -871,7 +857,7 @@ _GLOBAL(enter_prom) /* Restore the MSR (back to 64 bits) */ ld r0,_MSR(r1) - mtmsrd r0 + MTMSRD(r0) isync /* Restore other registers */ @@ -881,18 +867,6 @@ _GLOBAL(enter_prom) REST_10GPRS(22, r1) ld r4,_CCR(r1) mtcr r4 - ld r5,_CTR(r1) - mtctr r5 - ld r6,_XER(r1) - mtspr SPRN_XER,r6 - ld r7,_DAR(r1) - mtdar r7 - ld r8,_DSISR(r1) - mtdsisr r8 - ld r9,_SRR0(r1) - mtsrr0 r9 - ld r10,_SRR1(r1) - mtsrr1 r10 addi r1,r1,PROM_FRAME_SIZE ld r0,16(r1) |