Commit 6c1719942e19 ("powerpc/of: Remove useless register save/restore
when calling OF back") removed the saving of srr0 and srr1 when calling
into OpenFirmware. Commit e31aa453bbc4 ("powerpc: Use LOAD_REG_IMMEDIATE
only for constants on 64-bit") did the same for rtas.This means we don't need to save the extra stack space and can use the common SWITCH_FRAME_SIZE. There were already no users of _SRR0 and _SRR1 so we can remove them too. Link: https://github.com/linuxppc/linux/issues/83 Signed-off-by: Joel Stanley <j...@jms.id.au> --- arch/powerpc/kernel/asm-offsets.c | 9 --------- arch/powerpc/kernel/entry_64.S | 10 +++++----- 2 files changed, 5 insertions(+), 14 deletions(-) diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index a6d70fd2e499..2eb4923f8468 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -280,11 +280,6 @@ int main(void) /* Interrupt register frame */ DEFINE(INT_FRAME_SIZE, STACK_INT_FRAME_SIZE); DEFINE(SWITCH_FRAME_SIZE, STACK_FRAME_OVERHEAD + sizeof(struct pt_regs)); -#ifdef CONFIG_PPC64 - /* Create extra stack space for SRR0 and SRR1 when calling prom/rtas. */ - DEFINE(PROM_FRAME_SIZE, STACK_FRAME_OVERHEAD + sizeof(struct pt_regs) + 16); - DEFINE(RTAS_FRAME_SIZE, STACK_FRAME_OVERHEAD + sizeof(struct pt_regs) + 16); -#endif /* CONFIG_PPC64 */ STACK_PT_REGS_OFFSET(GPR0, gpr[0]); STACK_PT_REGS_OFFSET(GPR1, gpr[1]); STACK_PT_REGS_OFFSET(GPR2, gpr[2]); @@ -328,10 +323,6 @@ int main(void) STACK_PT_REGS_OFFSET(_ESR, dsisr); #else /* CONFIG_PPC64 */ STACK_PT_REGS_OFFSET(SOFTE, softe); - - /* These _only_ to be used with {PROM,RTAS}_FRAME_SIZE!!! */ - DEFINE(_SRR0, STACK_FRAME_OVERHEAD+sizeof(struct pt_regs)); - DEFINE(_SRR1, STACK_FRAME_OVERHEAD+sizeof(struct pt_regs)+8); #endif /* CONFIG_PPC64 */ #if defined(CONFIG_PPC32) diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index ed6f6c7f4264..7db00ee6be48 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -1124,7 +1124,7 @@ _ASM_NOKPROBE_SYMBOL(fast_exception_return); _GLOBAL(enter_rtas) mflr r0 std r0,16(r1) - stdu r1,-RTAS_FRAME_SIZE(r1) /* Save SP and create stack space. */ + stdu r1,-SWITCH_FRAME_SIZE(r1) /* Save SP and create stack space. */ /* Because RTAS is running in 32b mode, it clobbers the high order half * of all registers that it saves. We therefore save those registers @@ -1256,7 +1256,7 @@ rtas_restore_regs: ld r8,_DSISR(r1) mtdsisr r8 - addi r1,r1,RTAS_FRAME_SIZE /* Unstack our frame */ + addi r1,r1,SWITCH_FRAME_SIZE /* Unstack our frame */ ld r0,16(r1) /* get return address */ mtlr r0 @@ -1267,7 +1267,7 @@ rtas_restore_regs: _GLOBAL(enter_prom) mflr r0 std r0,16(r1) - stdu r1,-PROM_FRAME_SIZE(r1) /* Save SP and create stack space */ + stdu r1,-SWITCH_FRAME_SIZE(r1) /* Save SP and create stack space */ /* Because PROM is running in 32b mode, it clobbers the high order half * of all registers that it saves. We therefore save those registers @@ -1324,8 +1324,8 @@ _GLOBAL(enter_prom) REST_10GPRS(22, r1) ld r4,_CCR(r1) mtcr r4 - - addi r1,r1,PROM_FRAME_SIZE + + addi r1,r1,SWITCH_FRAME_SIZE ld r0,16(r1) mtlr r0 blr -- 2.17.1
