aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorChristophe Leroy <christophe.leroy@c-s.fr>2018-04-17 19:08:18 +0200
committerMichael Ellerman <mpe@ellerman.id.au>2018-05-18 00:09:06 +1000
commita1f3ae3fe8a1883c339f1bc89d1c941b3809e084 (patch)
treed830fbdffa3dac41aba47c6683b3fe08413ebc7e
parentpowerpc: Avoid an unnecessary test and branch in longjmp() (diff)
downloadlinux-dev-a1f3ae3fe8a1883c339f1bc89d1c941b3809e084.tar.xz
linux-dev-a1f3ae3fe8a1883c339f1bc89d1c941b3809e084.zip
powerpc/32: Use stmw/lmw for registers save/restore in asm
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> [mpe: PPC32 is BE only, so drop the endian checks] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
-rw-r--r--arch/powerpc/include/asm/ppc_asm.h6
-rw-r--r--arch/powerpc/kernel/misc.S10
-rw-r--r--arch/powerpc/kernel/ppc_save_regs.S4
3 files changed, 16 insertions, 4 deletions
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index 13f7f4c0e1ea..75ece56dcd62 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -80,10 +80,8 @@ 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)
-#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)
+#define SAVE_NVGPRS(base) stmw 13, GPR0+4*13(base)
+#define REST_NVGPRS(base) lmw 13, GPR0+4*13(base)
#endif
#define SAVE_2GPRS(n, base) SAVE_GPR(n, base); SAVE_GPR(n+1, base)
diff --git a/arch/powerpc/kernel/misc.S b/arch/powerpc/kernel/misc.S
index c60b70da1e4b..2f18fc1368d0 100644
--- a/arch/powerpc/kernel/misc.S
+++ b/arch/powerpc/kernel/misc.S
@@ -60,6 +60,10 @@ _GLOBAL(setjmp)
PPC_STL r0,0(r3)
PPC_STL r1,SZL(r3)
PPC_STL r2,2*SZL(r3)
+#ifdef CONFIG_PPC32
+ mfcr r12
+ stmw r12, 3*SZL(r3)
+#else
mfcr r0
PPC_STL r0,3*SZL(r3)
PPC_STL r13,4*SZL(r3)
@@ -81,10 +85,15 @@ _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)
+#ifdef CONFIG_PPC32
+ 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)
@@ -106,6 +115,7 @@ _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..8afbe213d729 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)
+#ifdef CONFIG_PPC32
+ 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)