sparc32: Implement hard_smp_processor_id() via instruction patching.

This is the last non-trivial user of btfixup.

Like sparc64, use a special patch section to resolve the various
implementations of how to read the current CPU's ID when we don't
have current_thread_info()->cpu necessarily available.

Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Sam Ravnborg <sam@ravnborg.org>

2 files changed, 19 insertions, 73 deletions

diff --git a/arch/sparc/include/asm/smp_32.h b/arch/sparc/include/asm/smp_32.h
index 01c51c7..f5b325e 100644
--- a/arch/sparc/include/asm/smp_32.h
+++ b/arch/sparc/include/asm/smp_32.h
@@ -59,12 +59,9 @@ void smp_bogo(struct seq_file *);
 void smp_info(struct seq_file *);
 
 BTFIXUPDEF_CALL(void, smp_cross_call, smpfunc_t, cpumask_t, unsigned long, unsigned long, unsigned long, unsigned long)
-BTFIXUPDEF_CALL(int, __hard_smp_processor_id, void)
 BTFIXUPDEF_CALL(void, smp_ipi_resched, int);
 BTFIXUPDEF_CALL(void, smp_ipi_single, int);
 BTFIXUPDEF_CALL(void, smp_ipi_mask_one, int);
-BTFIXUPDEF_BLACKBOX(hard_smp_processor_id)
-BTFIXUPDEF_BLACKBOX(load_current)
 
 #define smp_cross_call(func,mask,arg1,arg2,arg3,arg4) BTFIXUP_CALL(smp_cross_call)(func,mask,arg1,arg2,arg3,arg4)
 
@@ -117,45 +114,7 @@ extern inline int hard_smpleon_processor_id(void)
 	return cpuid;
 }
 
-#ifndef MODULE
-static inline int hard_smp_processor_id(void)
-{
-	int cpuid;
-
-	/* Black box - sun4m
-		__asm__ __volatile__("rd %%tbr, %0\n\t"
-				     "srl %0, 12, %0\n\t"
-				     "and %0, 3, %0\n\t" :
-				     "=&r" (cpuid));
-	             - sun4d
-		__asm__ __volatile__("lda [%g0] ASI_M_VIKING_TMP1, %0\n\t"
-				     "nop; nop" :
-				     "=&r" (cpuid));
-		     - leon
-		__asm__ __volatile__(	"rd %asr17, %0\n\t"
-					"srl %0, 0x1c, %0\n\t"
-					"nop\n\t" :
-					"=&r" (cpuid));
-	   See btfixup.h and btfixupprep.c to understand how a blackbox works.
-	 */
-	__asm__ __volatile__("sethi %%hi(___b_hard_smp_processor_id), %0\n\t"
-			     "sethi %%hi(boot_cpu_id), %0\n\t"
-			     "ldub [%0 + %%lo(boot_cpu_id)], %0\n\t" :
-			     "=&r" (cpuid));
-	return cpuid;
-}
-#else
-static inline int hard_smp_processor_id(void)
-{
-	int cpuid;
-
-	__asm__ __volatile__("mov %%o7, %%g1\n\t"
-			     "call ___f___hard_smp_processor_id\n\t"
-			     " nop\n\t"
-			     "mov %%g2, %0\n\t" : "=r"(cpuid) : : "g1", "g2");
-	return cpuid;
-}
-#endif
+extern int hard_smp_processor_id(void);
 
 #define raw_smp_processor_id()		(current_thread_info()->cpu)
 
diff --git a/arch/sparc/include/asm/winmacro.h b/arch/sparc/include/asm/winmacro.h
index a9be04b..9b7b217 100644
--- a/arch/sparc/include/asm/winmacro.h
+++ b/arch/sparc/include/asm/winmacro.h
@@ -103,37 +103,24 @@
         st       %scratch, [%cur_reg + TI_W_SAVED];
 
 #ifdef CONFIG_SMP
-/* Results of LOAD_CURRENT() after BTFIXUP for SUN4M, SUN4D & LEON (comments) */
-#define LOAD_CURRENT4M(dest_reg, idreg) \
-        rd       %tbr, %idreg; \
-	sethi    %hi(current_set), %dest_reg; \
-        srl      %idreg, 10, %idreg; \
-	or       %dest_reg, %lo(current_set), %dest_reg; \
-	and      %idreg, 0xc, %idreg; \
-	ld       [%idreg + %dest_reg], %dest_reg;
-
-#define LOAD_CURRENT4D(dest_reg, idreg) \
-	lda	 [%g0] ASI_M_VIKING_TMP1, %idreg; \
-	sethi	%hi(C_LABEL(current_set)), %dest_reg; \
-	sll	%idreg, 2, %idreg; \
-	or	%dest_reg, %lo(C_LABEL(current_set)), %dest_reg; \
-	ld	[%idreg + %dest_reg], %dest_reg;
-
-#define LOAD_CURRENT_LEON(dest_reg, idreg)			\
-	rd	%asr17, %idreg;					\
-	sethi	%hi(current_set), %dest_reg;			\
-	srl	%idreg, 0x1c, %idreg;				\
-	or	%dest_reg, %lo(current_set), %dest_reg;		\
-	sll	%idreg, 0x2, %idreg;				\
-	ld	[%idreg + %dest_reg], %dest_reg;
-
-/* Blackbox - take care with this... - check smp4m and smp4d before changing this. */
-#define LOAD_CURRENT(dest_reg, idreg) 					\
-	sethi	 %hi(___b_load_current), %idreg;			\
-	sethi    %hi(current_set), %dest_reg; 			\
-	sethi    %hi(boot_cpu_id4), %idreg; 			\
-	or       %dest_reg, %lo(current_set), %dest_reg; 	\
-	ldub	 [%idreg + %lo(boot_cpu_id4)], %idreg;		\
+#define LOAD_CURRENT(dest_reg, idreg) 			\
+661:	rd	%tbr, %idreg;				\
+	srl	%idreg, 10, %idreg;			\
+	and	%idreg, 0xc, %idreg;			\
+	.section	.cpuid_patch, "ax";		\
+	/* Instruction location. */			\
+	.word		661b;				\
+	/* SUN4D implementation. */			\
+	lda	 [%g0] ASI_M_VIKING_TMP1, %idreg;	\
+	sll	 %idreg, 2, %idreg;			\
+	nop;						\
+	/* LEON implementation. */			\
+	rd 	%asr17, %idreg;				\
+	srl	%idreg, 0x1c, %idreg;			\
+	sll	%idreg, 0x02, %idreg;			\
+	.previous;					\
+	sethi    %hi(current_set), %dest_reg; 		\
+	or       %dest_reg, %lo(current_set), %dest_reg;\
 	ld       [%idreg + %dest_reg], %dest_reg;
 #else
 #define LOAD_CURRENT(dest_reg, idreg) \