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authorJoel Stanley <joel@jms.id.au>2018-10-12 05:44:06 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2018-10-13 14:21:25 +0300
commited9e84a4d703243a232e6549a13dedfaf0d5d2d8 (patch)
tree538b998d74ac95a0c7dfc6f0e1998c46535c36d4
parent65b9fdadfc4d87e2577b791fb3495cd39c93d8c0 (diff)
downloadlinux-ed9e84a4d703243a232e6549a13dedfaf0d5d2d8.tar.xz
powerpc: Use SWITCH_FRAME_SIZE for prom and rtas entry
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 <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
-rw-r--r--arch/powerpc/kernel/asm-offsets.c9
-rw-r--r--arch/powerpc/kernel/entry_64.S10
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