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Subject[PATCH v2 2/2] powerpc/32be: use stmw/lmw for registers save/restore in asm
Date
arch/powerpc/Makefile activates -mmultiple on BE PPC32 configs
in order to use multiple word instructions in functions entry/exit

The patch does the same for the asm parts, for consistency

On processors like the 8xx on which insn fetching is pretty slow,
this speeds up registers save/restore

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
v2: Swapped both patches in the serie to reduce number of impacted
lines and added the same modification in ppc_save_regs()

arch/powerpc/include/asm/ppc_asm.h | 5 +++++
arch/powerpc/kernel/misc.S | 10 ++++++++++
arch/powerpc/kernel/ppc_save_regs.S | 4 ++++
3 files changed, 19 insertions(+)

diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index 13f7f4c0e1ea..4bb765d0b758 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -80,11 +80,16 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR)
#else
#define SAVE_GPR(n, base) stw n,GPR0+4*(n)(base)
#define REST_GPR(n, base) lwz n,GPR0+4*(n)(base)
+#ifdef CONFIG_CPU_BIG_ENDIAN
+#define SAVE_NVGPRS(base) stmw 13, GPR0+4*13(base)
+#define REST_NVGPRS(base) lmw 13, GPR0+4*13(base)
+#else
#define SAVE_NVGPRS(base) SAVE_GPR(13, base); SAVE_8GPRS(14, base); \
SAVE_10GPRS(22, base)
#define REST_NVGPRS(base) REST_GPR(13, base); REST_8GPRS(14, base); \
REST_10GPRS(22, base)
#endif
+#endif

#define SAVE_2GPRS(n, base) SAVE_GPR(n, base); SAVE_GPR(n+1, base)
#define SAVE_4GPRS(n, base) SAVE_2GPRS(n, base); SAVE_2GPRS(n+2, base)
diff --git a/arch/powerpc/kernel/misc.S b/arch/powerpc/kernel/misc.S
index 746ee0320ad4..a316d90a5c26 100644
--- a/arch/powerpc/kernel/misc.S
+++ b/arch/powerpc/kernel/misc.S
@@ -49,6 +49,10 @@ _GLOBAL(setjmp)
PPC_STL r0,0(r3)
PPC_STL r1,SZL(r3)
PPC_STL r2,2*SZL(r3)
+#if defined(CONFIG_PPC32) && defined(CONFIG_CPU_BIG_ENDIAN)
+ mfcr r12
+ stmw r12, 3*SZL(r3)
+#else
mfcr r0
PPC_STL r0,3*SZL(r3)
PPC_STL r13,4*SZL(r3)
@@ -70,10 +74,15 @@ _GLOBAL(setjmp)
PPC_STL r29,20*SZL(r3)
PPC_STL r30,21*SZL(r3)
PPC_STL r31,22*SZL(r3)
+#endif
li r3,0
blr

_GLOBAL(longjmp)
+#if defined(CONFIG_PPC32) && defined(CONFIG_CPU_BIG_ENDIAN)
+ lmw r12, 3*SZL(r3)
+ mtcrf 0x38, r12
+#else
PPC_LL r13,4*SZL(r3)
PPC_LL r14,5*SZL(r3)
PPC_LL r15,6*SZL(r3)
@@ -95,6 +104,7 @@ _GLOBAL(longjmp)
PPC_LL r31,22*SZL(r3)
PPC_LL r0,3*SZL(r3)
mtcrf 0x38,r0
+#endif
PPC_LL r0,0(r3)
PPC_LL r1,SZL(r3)
PPC_LL r2,2*SZL(r3)
diff --git a/arch/powerpc/kernel/ppc_save_regs.S b/arch/powerpc/kernel/ppc_save_regs.S
index 1b1787d52896..d60316e70514 100644
--- a/arch/powerpc/kernel/ppc_save_regs.S
+++ b/arch/powerpc/kernel/ppc_save_regs.S
@@ -25,6 +25,9 @@
*/
_GLOBAL(ppc_save_regs)
PPC_STL r0,0*SZL(r3)
+#if defined(CONFIG_PPC32) && defined(CONFIG_CPU_BIG_ENDIAN)
+ stmw r2, 2*SZL(r3)
+#else
PPC_STL r2,2*SZL(r3)
PPC_STL r3,3*SZL(r3)
PPC_STL r4,4*SZL(r3)
@@ -55,6 +58,7 @@ _GLOBAL(ppc_save_regs)
PPC_STL r29,29*SZL(r3)
PPC_STL r30,30*SZL(r3)
PPC_STL r31,31*SZL(r3)
+#endif
/* go up one stack frame for SP */
PPC_LL r4,0(r1)
PPC_STL r4,1*SZL(r3)
--
2.13.3
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