powerpc/8xx: mfspr SPRN_TBRx in lieu of mftb/mftbu is not supported

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@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>

5 files changed, 37 insertions, 0 deletions

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 3c1acc31a092..f595b98079ee 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -366,6 +366,8 @@ 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 5c45787d551e..fa8388ed94c5 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -1174,12 +1174,19 @@
 
 #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