From: LEROY Christophe <christophe.leroy@xxxxxx>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit ae2163be10ac6090e7aeed72591e2d7fabb1cdda upstream.
Commit beb2dc0a7a84be003ce54e98b95d65cc66e6e536 breaks the MPC8xx which
seems to not support using mfspr SPRN_TBRx instead of mftb/mftbu
despite what is written in the reference manual.
This patch reverts to the use of mftb/mftbu when CONFIG_8xx is
selected.
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
Signed-off-by: Scott Wood <scottwood@xxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
arch/powerpc/boot/util.S | 14 ++++++++++++++
arch/powerpc/include/asm/ppc_asm.h | 2 ++
arch/powerpc/include/asm/reg.h | 7 +++++++
arch/powerpc/include/asm/timex.h | 8 ++++++++
arch/powerpc/kernel/vdso32/gettimeofday.S | 6 ++++++
5 files changed, 37 insertions(+)
diff --git a/arch/powerpc/boot/util.S b/arch/powerpc/boot/util.S
index 5143228e3e5f..6636b1d7821b 100644
--- a/arch/powerpc/boot/util.S
+++ b/arch/powerpc/boot/util.S
@@ -71,18 +71,32 @@ udelay:
add r4,r4,r5
addi r4,r4,-1
divw r4,r4,r5 /* BUS ticks */
+#ifdef CONFIG_8xx
+1: mftbu r5
+ mftb r6
+ mftbu r7
+#else
1: mfspr r5, SPRN_TBRU
mfspr r6, SPRN_TBRL
mfspr r7, SPRN_TBRU
+#endif
cmpw 0,r5,r7
bne 1b /* Get [synced] base time */
addc r9,r6,r4 /* Compute end time */
addze r8,r5
+#ifdef CONFIG_8xx
+2: mftbu r5
+#else
2: mfspr r5, SPRN_TBRU
+#endif
cmpw 0,r5,r8
blt 2b
bgt 3f
+#ifdef CONFIG_8xx
+ mftb r6
+#else
mfspr r6, SPRN_TBRL
+#endif
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 c2dcfaa51987..0d2d0f03163b 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -438,6 +438,8 @@ 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)
+#elif defined(CONFIG_8xx)
+#define MFTB(dest) mftb dest
#else
#define MFTB(dest) mfspr dest, SPRN_TBRL
#endif
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 10d1ef016bf1..7ca729cac073 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -1154,12 +1154,19 @@
#else /* __powerpc64__ */
+#if defined(CONFIG_8xx)
+#define mftbl() ({unsigned long rval; \
+ asm volatile("mftbl %0" : "=r" (rval)); rval;})
+#define mftbu() ({unsigned long rval; \
+ asm volatile("mftbu %0" : "=r" (rval)); rval;})
+#else
#define mftbl() ({unsigned long rval; \
asm volatile("mfspr %0, %1" : "=r" (rval) : \
"i" (SPRN_TBRL)); rval;})
#define mftbu() ({unsigned long rval; \
asm volatile("mfspr %0, %1" : "=r" (rval) : \
"i" (SPRN_TBRU)); rval;})
+#endif
#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 18908caa1f3b..2cf846edb3fc 100644
--- a/arch/powerpc/include/asm/timex.h
+++ b/arch/powerpc/include/asm/timex.h
@@ -29,7 +29,11 @@ static inline cycles_t get_cycles(void)
ret = 0;
__asm__ __volatile__(
+#ifdef CONFIG_8xx
+ "97: mftb %0\n"
+#else
"97: mfspr %0, %2\n"
+#endif
"99:\n"
".section __ftr_fixup,\"a\"\n"
".align 2\n"
@@ -41,7 +45,11 @@ static inline cycles_t get_cycles(void)
" .long 0\n"
" .long 0\n"
".previous"
+#ifdef CONFIG_8xx
+ : "=r" (ret) : "i" (CPU_FTR_601));
+#else
: "=r" (ret) : "i" (CPU_FTR_601), "i" (SPRN_TBRL));
+#endif
return ret;
#endif
}
diff --git a/arch/powerpc/kernel/vdso32/gettimeofday.S b/arch/powerpc/kernel/vdso32/gettimeofday.S
index 6b1f2a6d5517..6b2b69616e77 100644
--- a/arch/powerpc/kernel/vdso32/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
@@ -232,9 +232,15 @@ __do_get_tspec:
lwz r6,(CFG_TB_ORIG_STAMP+4)(r9)
/* Get a stable TB value */
+#ifdef CONFIG_8xx
+2: mftbu r3
+ mftbl r4
+ mftbu r0
+#else
2: mfspr r3, SPRN_TBRU
mfspr r4, SPRN_TBRL
mfspr r0, SPRN_TBRU
+#endif
cmplw cr0,r3,r0
bne- 2b
--
1.9.2
--
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