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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2013-09-23 12:04:45 +1000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2013-10-11 16:48:34 +1100 |
| commit | 5c0484e25ec03243d4c2f2d4416d4a13efc77f6a (patch) | |
| tree | fe31fb5e5be50119f39d2e22953f13d8ace85cb1 /arch/powerpc/kernel/entry_64.S | |
| parent | c57a5ce0df04be61bafedc0f3043d568103c7ab5 (diff) | |
| download | linux-5c0484e25ec03243d4c2f2d4416d4a13efc77f6a.tar.gz | |
powerpc: Endian safe trampoline
Create a trampoline that works in either endian and flips to
the expected endian. Use it for primary and secondary thread
entry as well as RTAS and OF call return.
Credit for finding the magic instruction goes to Paul Mackerras
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/entry_64.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 36 |
1 files changed, 20 insertions, 16 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index c04cdf70d48753..889ea2b19383ac 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -1017,7 +1017,7 @@ _GLOBAL(enter_rtas) li r9,1 rldicr r9,r9,MSR_SF_LG,(63-MSR_SF_LG) - ori r9,r9,MSR_IR|MSR_DR|MSR_FE0|MSR_FE1|MSR_FP|MSR_RI + ori r9,r9,MSR_IR|MSR_DR|MSR_FE0|MSR_FE1|MSR_FP|MSR_RI|MSR_LE andc r6,r0,r9 sync /* disable interrupts so SRR0/1 */ mtmsrd r0 /* don't get trashed */ @@ -1032,6 +1032,8 @@ _GLOBAL(enter_rtas) b . /* prevent speculative execution */ _STATIC(rtas_return_loc) + FIXUP_ENDIAN + /* relocation is off at this point */ GET_PACA(r4) clrldi r4,r4,2 /* convert to realmode address */ @@ -1103,28 +1105,30 @@ _GLOBAL(enter_prom) std r10,_CCR(r1) std r11,_MSR(r1) - /* Get the PROM entrypoint */ - mtlr r4 + /* Put PROM address in SRR0 */ + mtsrr0 r4 + + /* Setup our trampoline return addr in LR */ + bcl 20,31,$+4 +0: mflr r4 + addi r4,r4,(1f - 0b) + mtlr r4 - /* Switch MSR to 32 bits mode + /* Prepare a 32-bit mode big endian MSR */ #ifdef CONFIG_PPC_BOOK3E rlwinm r11,r11,0,1,31 - mtmsr r11 + mtsrr1 r11 + rfi #else /* CONFIG_PPC_BOOK3E */ - mfmsr r11 - li r12,1 - rldicr r12,r12,MSR_SF_LG,(63-MSR_SF_LG) - andc r11,r11,r12 - li r12,1 - rldicr r12,r12,MSR_ISF_LG,(63-MSR_ISF_LG) - andc r11,r11,r12 - mtmsrd r11 + LOAD_REG_IMMEDIATE(r12, MSR_SF | MSR_ISF | MSR_LE) + andc r11,r11,r12 + mtsrr1 r11 + rfid #endif /* CONFIG_PPC_BOOK3E */ - isync - /* Enter PROM here... */ - blrl +1: /* Return from OF */ + FIXUP_ENDIAN /* Just make sure that r1 top 32 bits didn't get * corrupt by OF |