From beb2dc0a7a84be003ce54e98b95d65cc66e6e536 Mon Sep 17 00:00:00 2001 From: Scott Wood Date: Tue, 20 Aug 2013 19:33:12 -0500 Subject: [PATCH] powerpc: Convert some mftb/mftbu into mfspr Some CPUs (such as e500v1/v2) don't implement mftb and will take a trap. mfspr should work on everything that has a timebase, and is the preferred instruction according to ISA v2.06. Currently we get away with mftb on 85xx because the assembler converts it to mfspr due to -Wa,-me500. However, that flag has other effects that are undesireable for certain targets (e.g. lwsync is converted to sync), and is hostile to multiplatform kernels. Thus we would like to stop setting it for all e500-family builds. mftb/mftbu instances which are in 85xx code or common code are converted. Instances which will never run on 85xx are left alone. Signed-off-by: Scott Wood --- arch/powerpc/boot/ppc_asm.h | 3 +++ arch/powerpc/boot/util.S | 10 +++++----- arch/powerpc/include/asm/ppc_asm.h | 4 ++-- arch/powerpc/include/asm/reg.h | 15 ++++++++++----- arch/powerpc/include/asm/timex.h | 4 ++-- arch/powerpc/kernel/vdso32/gettimeofday.S | 6 +++--- arch/powerpc/platforms/85xx/smp.c | 6 ++++-- 7 files changed, 29 insertions(+), 19 deletions(-) diff --git a/arch/powerpc/boot/ppc_asm.h b/arch/powerpc/boot/ppc_asm.h index 1c2c2817f9b7..eb0e98be69e0 100644 --- a/arch/powerpc/boot/ppc_asm.h +++ b/arch/powerpc/boot/ppc_asm.h @@ -59,4 +59,7 @@ #define r30 30 #define r31 31 +#define SPRN_TBRL 268 +#define SPRN_TBRU 269 + #endif /* _PPC64_PPC_ASM_H */ diff --git a/arch/powerpc/boot/util.S b/arch/powerpc/boot/util.S index 427ddfc11991..5143228e3e5f 100644 --- a/arch/powerpc/boot/util.S +++ b/arch/powerpc/boot/util.S @@ -71,18 +71,18 @@ udelay: add r4,r4,r5 addi r4,r4,-1 divw r4,r4,r5 /* BUS ticks */ -1: mftbu r5 - mftb r6 - mftbu r7 +1: mfspr r5, SPRN_TBRU + mfspr r6, SPRN_TBRL + mfspr r7, SPRN_TBRU cmpw 0,r5,r7 bne 1b /* Get [synced] base time */ addc r9,r6,r4 /* Compute end time */ addze r8,r5 -2: mftbu r5 +2: mfspr r5, SPRN_TBRU cmpw 0,r5,r8 blt 2b bgt 3f - mftb r6 + mfspr r6, SPRN_TBRL cmpw 0,r6,r9 blt 2b 3: blr diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h index 8fdd3da134e0..599545738af3 100644 --- a/arch/powerpc/include/asm/ppc_asm.h +++ b/arch/powerpc/include/asm/ppc_asm.h @@ -433,13 +433,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_601) #if defined(CONFIG_PPC_CELL) || defined(CONFIG_PPC_FSL_BOOK3E) #define MFTB(dest) \ -90: mftb dest; \ +90: mfspr dest, SPRN_TBRL; \ BEGIN_FTR_SECTION_NESTED(96); \ cmpwi dest,0; \ beq- 90b; \ END_FTR_SECTION_NESTED(CPU_FTR_CELL_TB_BUG, CPU_FTR_CELL_TB_BUG, 96) #else -#define MFTB(dest) mftb dest +#define MFTB(dest) mfspr dest, SPRN_TBRL #endif #ifndef CONFIG_SMP diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index 55b03079d197..64264bf601f5 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -1120,7 +1120,7 @@ #if defined(CONFIG_PPC_CELL) || defined(CONFIG_PPC_FSL_BOOK3E) #define mftb() ({unsigned long rval; \ asm volatile( \ - "90: mftb %0;\n" \ + "90: mfspr %0, %2;\n" \ "97: cmpwi %0,0;\n" \ " beq- 90b;\n" \ "99:\n" \ @@ -1134,18 +1134,23 @@ " .llong 0\n" \ " .llong 0\n" \ ".previous" \ - : "=r" (rval) : "i" (CPU_FTR_CELL_TB_BUG)); rval;}) + : "=r" (rval) \ + : "i" (CPU_FTR_CELL_TB_BUG), "i" (SPRN_TBRL)); \ + rval;}) #else #define mftb() ({unsigned long rval; \ - asm volatile("mftb %0" : "=r" (rval)); rval;}) + asm volatile("mfspr %0, %1" : \ + "=r" (rval) : "i" (SPRN_TBRL)); rval;}) #endif /* !CONFIG_PPC_CELL */ #else /* __powerpc64__ */ #define mftbl() ({unsigned long rval; \ - asm volatile("mftbl %0" : "=r" (rval)); rval;}) + asm volatile("mfspr %0, %1" : "=r" (rval) : \ + "i" (SPRN_TBRL)); rval;}) #define mftbu() ({unsigned long rval; \ - asm volatile("mftbu %0" : "=r" (rval)); rval;}) + asm volatile("mfspr %0, %1" : "=r" (rval) : \ + "i" (SPRN_TBRU)); rval;}) #endif /* !__powerpc64__ */ #define mttbl(v) asm volatile("mttbl %0":: "r"(v)) diff --git a/arch/powerpc/include/asm/timex.h b/arch/powerpc/include/asm/timex.h index c55e14f7ef44..18908caa1f3b 100644 --- a/arch/powerpc/include/asm/timex.h +++ b/arch/powerpc/include/asm/timex.h @@ -29,7 +29,7 @@ static inline cycles_t get_cycles(void) ret = 0; __asm__ __volatile__( - "97: mftb %0\n" + "97: mfspr %0, %2\n" "99:\n" ".section __ftr_fixup,\"a\"\n" ".align 2\n" @@ -41,7 +41,7 @@ static inline cycles_t get_cycles(void) " .long 0\n" " .long 0\n" ".previous" - : "=r" (ret) : "i" (CPU_FTR_601)); + : "=r" (ret) : "i" (CPU_FTR_601), "i" (SPRN_TBRL)); return ret; #endif } diff --git a/arch/powerpc/kernel/vdso32/gettimeofday.S b/arch/powerpc/kernel/vdso32/gettimeofday.S index 27e2f623210b..6b1f2a6d5517 100644 --- a/arch/powerpc/kernel/vdso32/gettimeofday.S +++ b/arch/powerpc/kernel/vdso32/gettimeofday.S @@ -232,9 +232,9 @@ __do_get_tspec: lwz r6,(CFG_TB_ORIG_STAMP+4)(r9) /* Get a stable TB value */ -2: mftbu r3 - mftbl r4 - mftbu r0 +2: mfspr r3, SPRN_TBRU + mfspr r4, SPRN_TBRL + mfspr r0, SPRN_TBRU cmplw cr0,r3,r0 bne- 2b diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c index ea7e62910891..281b7f01df63 100644 --- a/arch/powerpc/platforms/85xx/smp.c +++ b/arch/powerpc/platforms/85xx/smp.c @@ -83,11 +83,13 @@ static void mpc85xx_give_timebase(void) { u64 prev; - asm volatile("mftb %0" : "=r" (timebase)); + asm volatile("mfspr %0, %1" : "=r" (timebase) : + "i" (SPRN_TBRL)); do { prev = timebase; - asm volatile("mftb %0" : "=r" (timebase)); + asm volatile("mfspr %0, %1" : "=r" (timebase) : + "i" (SPRN_TBRL)); } while (prev != timebase); } #else -- 2.30.2