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>

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)
 

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; \
+#define LOAD_CURRENT(dest_reg, idreg) 			\
+661:	rd	%tbr, %idreg;				\
 	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) \
+	.section	.cpuid_patch, "ax";		\
+	/* Instruction location. */			\
+	.word		661b;				\
+	/* SUN4D implementation. */			\
 	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)			\
+	nop;						\
+	/* LEON implementation. */			\
 	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;			\
+	sll	%idreg, 0x02, %idreg;			\
+	.previous;					\
 	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;		\
+	or       %dest_reg, %lo(current_set), %dest_reg;\
 	ld       [%idreg + %dest_reg], %dest_reg;
 #else
 #define LOAD_CURRENT(dest_reg, idreg) \

arch/sparc/kernel/entry.S

@@ -7,6 +7,7 @@
  * Copyright (C) 1997 Anton Blanchard (anton@progsoc.uts.edu.au)
  */
 
+#include <linux/linkage.h>
 #include <linux/errno.h>
 
 #include <asm/head.h>
@@ -1347,4 +1348,26 @@ flushw_all:
 	ret
 	 restore
 
+#ifdef CONFIG_SMP
+ENTRY(hard_smp_processor_id)
+661:	rd		%tbr, %g1
+	srl		%g1, 12, %o0
+	and		%o0, 3, %o0
+	.section	.cpuid_patch, "ax"
+	/* Instruction location. */
+	.word		661b
+	/* SUN4D implementation. */
+	lda		[%g0] ASI_M_VIKING_TMP1, %o0
+	nop
+	nop
+	/* LEON implementation. */
+	rd		%asr17, %o0
+	srl		%o0, 0x1c, %o0
+	nop
+	.previous
+	retl
+	 nop
+ENDPROC(hard_smp_processor_id)
+#endif
+
 /* End of entry.S */

arch/sparc/kernel/kernel.h

@@ -80,8 +80,6 @@ extern unsigned int patchme_maybe_smp_msg[];
 extern void floppy_hardint(void);
 
 /* trampoline_32.S */
-extern int __smp4m_processor_id(void);
-extern int __smp4d_processor_id(void);
 extern unsigned long sun4m_cpu_startup;
 extern unsigned long sun4d_cpu_startup;
 

arch/sparc/kernel/leon_smp.c

@@ -73,7 +73,7 @@ static inline unsigned long do_swap(volatile unsigned long *ptr,
 
 void __cpuinit leon_callin(void)
 {
-	int cpuid = hard_smpleon_processor_id();
+	int cpuid = hard_smp_processor_id();
 
 	local_ops->cache_all();
 	local_ops->tlb_all();
@@ -491,39 +491,12 @@ void leon_cross_call_irq(void)
 	ccall_info.processors_out[i] = 1;
 }
 
-void __init leon_blackbox_id(unsigned *addr)
-{
-	int rd = *addr & 0x3e000000;
-	int rs1 = rd >> 11;
-
-	/* patch places where ___b_hard_smp_processor_id appears */
-	addr[0] = 0x81444000 | rd;	/* rd %asr17, reg */
-	addr[1] = 0x8130201c | rd | rs1;	/* srl reg, 0x1c, reg */
-	addr[2] = 0x01000000;	/* nop */
-}
-
-void __init leon_blackbox_current(unsigned *addr)
-{
-	int rd = *addr & 0x3e000000;
-	int rs1 = rd >> 11;
-
-	/* patch LOAD_CURRENT macro where ___b_load_current appears */
-	addr[0] = 0x81444000 | rd;	/* rd %asr17, reg */
-	addr[2] = 0x8130201c | rd | rs1;	/* srl reg, 0x1c, reg */
-	addr[4] = 0x81282002 | rd | rs1;	/* sll reg, 0x2, reg */
-
-}
-
 void __init leon_init_smp(void)
 {
 	/* Patch ipi15 trap table */
 	t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_leon - linux_trap_ipi15_sun4m);
 
-	BTFIXUPSET_BLACKBOX(hard_smp_processor_id, leon_blackbox_id);
-	BTFIXUPSET_BLACKBOX(load_current, leon_blackbox_current);
 	BTFIXUPSET_CALL(smp_cross_call, leon_cross_call, BTFIXUPCALL_NORM);
-	BTFIXUPSET_CALL(__hard_smp_processor_id, __leon_processor_id,
-			BTFIXUPCALL_NORM);
 	BTFIXUPSET_CALL(smp_ipi_resched, leon_ipi_resched, BTFIXUPCALL_NORM);
 	BTFIXUPSET_CALL(smp_ipi_single, leon_ipi_single, BTFIXUPCALL_NORM);
 	BTFIXUPSET_CALL(smp_ipi_mask_one, leon_ipi_mask_one, BTFIXUPCALL_NORM);

arch/sparc/kernel/setup_32.c

@@ -192,6 +192,52 @@ extern int root_mountflags;
 
 char reboot_command[COMMAND_LINE_SIZE];
 
+struct cpuid_patch_entry {
+	unsigned int	addr;
+	unsigned int	sun4d[3];
+	unsigned int	leon[3];
+};
+extern struct cpuid_patch_entry __cpuid_patch, __cpuid_patch_end;
+
+static void __init per_cpu_patch(void)
+{
+	struct cpuid_patch_entry *p;
+
+	if (sparc_cpu_model == sun4m) {
+		/* Nothing to do, this is what the unpatched code
+		 * targets.
+		 */
+		return;
+	}
+
+	p = &__cpuid_patch;
+	while (p < &__cpuid_patch_end) {
+		unsigned long addr = p->addr;
+		unsigned int *insns;
+
+		switch (sparc_cpu_model) {
+		case sun4d:
+			insns = &p->sun4d[0];
+			break;
+
+		case sparc_leon:
+			insns = &p->leon[0];
+			break;
+		default:
+			prom_printf("Unknown cpu type, halting.\n");
+			prom_halt();
+		}
+		*(unsigned int *) (addr + 0) = insns[0];
+		*(unsigned int *) (addr + 4) = insns[1];
+		*(unsigned int *) (addr + 8) = insns[2];
+	}
+#ifdef CONFIG_SMP
+	local_ops->cache_all();
+#else
+	sparc32_cachetlb_ops->cache_all();
+#endif
+}
+
 enum sparc_cpu sparc_cpu_model;
 EXPORT_SYMBOL(sparc_cpu_model);
 
@@ -295,6 +341,11 @@ void __init setup_arch(char **cmdline_p)
 
 	paging_init();
 
+	/* Now that we have the cache ops hooked up, we can patch
+	 * instructions.
+	 */
+	per_cpu_patch();
+
 	smp_setup_cpu_possible_map();
 }
 

arch/sparc/kernel/sparc_ksyms_32.c

@@ -28,10 +28,5 @@ EXPORT_SYMBOL(__ndelay);
 EXPORT_SYMBOL(__ret_efault);
 EXPORT_SYMBOL(empty_zero_page);
 
-/* Defined using magic */
-#ifdef CONFIG_SMP
-EXPORT_SYMBOL(BTFIXUP_CALL(__hard_smp_processor_id));
-#endif
-
 /* Exporting a symbol from /init/main.c */
 EXPORT_SYMBOL(saved_command_line);

arch/sparc/kernel/sun4d_smp.c

@@ -52,7 +52,7 @@ static inline void show_leds(int cpuid)
 
 void __cpuinit smp4d_callin(void)
 {
-	int cpuid = hard_smp4d_processor_id();
+	int cpuid = hard_smp_processor_id();
 	unsigned long flags;
 
 	/* Show we are alive */
@@ -354,7 +354,7 @@ static void smp4d_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
 /* Running cross calls. */
 void smp4d_cross_call_irq(void)
 {
-	int i = hard_smp4d_processor_id();
+	int i = hard_smp_processor_id();
 
 	ccall_info.processors_in[i] = 1;
 	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
@@ -365,7 +365,7 @@ void smp4d_cross_call_irq(void)
 void smp4d_percpu_timer_interrupt(struct pt_regs *regs)
 {
 	struct pt_regs *old_regs;
-	int cpu = hard_smp4d_processor_id();
+	int cpu = hard_smp_processor_id();
 	struct clock_event_device *ce;
 	static int cpu_tick[NR_CPUS];
 	static char led_mask[] = { 0xe, 0xd, 0xb, 0x7, 0xb, 0xd };
@@ -391,24 +391,6 @@ void smp4d_percpu_timer_interrupt(struct pt_regs *regs)
 	set_irq_regs(old_regs);
 }
 
-void __init smp4d_blackbox_id(unsigned *addr)
-{
-	int rd = *addr & 0x3e000000;
-
-	addr[0] = 0xc0800800 | rd;		/* lda [%g0] ASI_M_VIKING_TMP1, reg */
-	addr[1] = 0x01000000;			/* nop */
-	addr[2] = 0x01000000;			/* nop */
-}
-
-void __init smp4d_blackbox_current(unsigned *addr)
-{
-	int rd = *addr & 0x3e000000;
-
-	addr[0] = 0xc0800800 | rd;		/* lda [%g0] ASI_M_VIKING_TMP1, reg */
-	addr[2] = 0x81282002 | rd | (rd >> 11);	/* sll reg, 2, reg */
-	addr[4] = 0x01000000;			/* nop */
-}
-
 void __init sun4d_init_smp(void)
 {
 	int i;
@@ -417,10 +399,7 @@ void __init sun4d_init_smp(void)
 	t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_sun4d - linux_trap_ipi15_sun4m);
 
 	/* And set btfixup... */
-	BTFIXUPSET_BLACKBOX(hard_smp_processor_id, smp4d_blackbox_id);
-	BTFIXUPSET_BLACKBOX(load_current, smp4d_blackbox_current);
 	BTFIXUPSET_CALL(smp_cross_call, smp4d_cross_call, BTFIXUPCALL_NORM);
-	BTFIXUPSET_CALL(__hard_smp_processor_id, __smp4d_processor_id, BTFIXUPCALL_NORM);
 	BTFIXUPSET_CALL(smp_ipi_resched, smp4d_ipi_resched, BTFIXUPCALL_NORM);
 	BTFIXUPSET_CALL(smp_ipi_single, smp4d_ipi_single, BTFIXUPCALL_NORM);
 	BTFIXUPSET_CALL(smp_ipi_mask_one, smp4d_ipi_mask_one, BTFIXUPCALL_NORM);

arch/sparc/kernel/sun4m_smp.c

@@ -281,32 +281,9 @@ void smp4m_percpu_timer_interrupt(struct pt_regs *regs)
 	set_irq_regs(old_regs);
 }
 
-static void __init smp4m_blackbox_id(unsigned *addr)
-{
-	int rd = *addr & 0x3e000000;
-	int rs1 = rd >> 11;
-
-	addr[0] = 0x81580000 | rd;		/* rd %tbr, reg */
-	addr[1] = 0x8130200c | rd | rs1;	/* srl reg, 0xc, reg */
-	addr[2] = 0x80082003 | rd | rs1;	/* and reg, 3, reg */
-}
-
-static void __init smp4m_blackbox_current(unsigned *addr)
-{
-	int rd = *addr & 0x3e000000;
-	int rs1 = rd >> 11;
-
-	addr[0] = 0x81580000 | rd;		/* rd %tbr, reg */
-	addr[2] = 0x8130200a | rd | rs1;	/* srl reg, 0xa, reg */
-	addr[4] = 0x8008200c | rd | rs1;	/* and reg, 0xc, reg */
-}
-
 void __init sun4m_init_smp(void)
 {
-	BTFIXUPSET_BLACKBOX(hard_smp_processor_id, smp4m_blackbox_id);
-	BTFIXUPSET_BLACKBOX(load_current, smp4m_blackbox_current);
 	BTFIXUPSET_CALL(smp_cross_call, smp4m_cross_call, BTFIXUPCALL_NORM);
-	BTFIXUPSET_CALL(__hard_smp_processor_id, __smp4m_processor_id, BTFIXUPCALL_NORM);
 	BTFIXUPSET_CALL(smp_ipi_resched, smp4m_ipi_resched, BTFIXUPCALL_NORM);
 	BTFIXUPSET_CALL(smp_ipi_single, smp4m_ipi_single, BTFIXUPCALL_NORM);
 	BTFIXUPSET_CALL(smp_ipi_mask_one, smp4m_ipi_mask_one, BTFIXUPCALL_NORM);

arch/sparc/kernel/trampoline_32.S

@@ -15,8 +15,8 @@
 #include <asm/contregs.h>
 #include <asm/thread_info.h>
 
-	.globl sun4m_cpu_startup, __smp4m_processor_id, __leon_processor_id
-	.globl sun4d_cpu_startup, __smp4d_processor_id
+	.globl sun4m_cpu_startup
+	.globl sun4d_cpu_startup
 
 	__CPUINIT
 	.align 4
@@ -94,24 +94,6 @@ smp_do_cpu_idle:
 	call	cpu_panic
 	 nop
 
-__smp4m_processor_id:
-	rd	%tbr, %g2
-	srl	%g2, 12, %g2
-	and	%g2, 3, %g2
-	retl
-	 mov	%g1, %o7
-
-__smp4d_processor_id:
-	lda	[%g0] ASI_M_VIKING_TMP1, %g2
-	retl
-	 mov	%g1, %o7
-
-__leon_processor_id:
-	rd     %asr17,%g2
-        srl    %g2,28,%g2
-	retl
-	 mov	%g1, %o7
-
 /* CPUID in bootbus can be found at PA 0xff0140000 */
 #define SUN4D_BOOTBUS_CPUID	0xf0140000