From: LEROY Christophe <[email protected]>

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 <[email protected]>
Signed-off-by: Scott Wood <[email protected]>
Signed-off-by: Jiri Slaby <[email protected]>
---
 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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to