[SPARC64]: Refine code sequences to get the cpu id.

On uniprocessor, it's always zero for optimize that.

On SMP, the jmpl to the stub kills the return address stack in the cpu
branch prediction logic, so expand the code sequence inline and use a
code patching section to fix things up.  This also always better and
explicit register selection, which will be taken advantage of in a
future changeset.

The hard_smp_processor_id() function is big, so do not inline it.

Fix up tests for Jalapeno to also test for Serrano chips too.  These
tests want "jbus Ultra-IIIi" cases to match, so that is what we should
test for.
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc64/kernel/entry.S

@@ -1628,84 +1628,10 @@ __flushw_user:
 2:	retl
 	 nop
 
-	/* Read cpu ID from hardware, return in %g6.
-	 * (callers_pc - 4) is in %g1.  Patched at boot time.
-	 *
-	 * Default is spitfire implementation.
-	 *
-	 * The instruction sequence needs to be 5 instructions
-	 * in order to fit the longest implementation, which is
-	 * currently starfire.
-	 */
-	.align		32
-	.globl		__get_cpu_id
-__get_cpu_id:
-	ldxa		[%g0] ASI_UPA_CONFIG, %g6
-	srlx		%g6, 17, %g6
-	jmpl		%g1 + 0x4, %g0
-	 and		%g6, 0x1f, %g6
-	nop
-
-__get_cpu_id_cheetah_safari:
-	ldxa		[%g0] ASI_SAFARI_CONFIG, %g6
-	srlx		%g6, 17, %g6
-	jmpl		%g1 + 0x4, %g0
-	 and		%g6, 0x3ff, %g6
-	nop
-
-__get_cpu_id_cheetah_jbus:
-	ldxa		[%g0] ASI_JBUS_CONFIG, %g6
-	srlx		%g6, 17, %g6
-	jmpl		%g1 + 0x4, %g0
-	 and		%g6, 0x1f, %g6
-	nop
-
-__get_cpu_id_starfire:
-	sethi		%hi(0x1fff40000d0 >> 9), %g6
-	sllx		%g6, 9, %g6
-	or		%g6, 0xd0, %g6
-	jmpl		%g1 + 0x4, %g0
-	 lduwa		[%g6] ASI_PHYS_BYPASS_EC_E, %g6
-
-	.globl		per_cpu_patch
-per_cpu_patch:
-	sethi		%hi(this_is_starfire), %o0
-	lduw		[%o0 + %lo(this_is_starfire)], %o1
-	sethi		%hi(__get_cpu_id_starfire), %o0
-	brnz,pn		%o1, 10f
-	 or		%o0, %lo(__get_cpu_id_starfire), %o0
-	sethi		%hi(tlb_type), %o0
-	lduw		[%o0 + %lo(tlb_type)], %o1
-	brz,pt		%o1, 11f
-	 nop
-	rdpr		%ver, %o0
-	srlx		%o0, 32, %o0
-	sethi		%hi(0x003e0016), %o1
-	or		%o1, %lo(0x003e0016), %o1
-	cmp		%o0, %o1
-	sethi		%hi(__get_cpu_id_cheetah_jbus), %o0
-	be,pn		%icc, 10f
-	 or		%o0, %lo(__get_cpu_id_cheetah_jbus), %o0
-	sethi		%hi(__get_cpu_id_cheetah_safari), %o0
-	or		%o0, %lo(__get_cpu_id_cheetah_safari), %o0
-10:
-	sethi		%hi(__get_cpu_id), %o1
-	or		%o1, %lo(__get_cpu_id), %o1
-	lduw		[%o0 + 0x00], %o2
-	stw		%o2, [%o1 + 0x00]
-	flush		%o1 + 0x00
-	lduw		[%o0 + 0x04], %o2
-	stw		%o2, [%o1 + 0x04]
-	flush		%o1 + 0x04
-	lduw		[%o0 + 0x08], %o2
-	stw		%o2, [%o1 + 0x08]
-	flush		%o1 + 0x08
-	lduw		[%o0 + 0x0c], %o2
-	stw		%o2, [%o1 + 0x0c]
-	flush		%o1 + 0x0c
-	lduw		[%o0 + 0x10], %o2
-	stw		%o2, [%o1 + 0x10]
-	flush		%o1 + 0x10
-11:
+#ifdef CONFIG_SMP
+	.globl		hard_smp_processor_id
+hard_smp_processor_id:
+	__GET_CPUID(%o0)
 	retl
 	 nop
+#endif

arch/sparc64/kernel/irq.c

@@ -39,6 +39,7 @@
 #include <asm/cache.h>
 #include <asm/cpudata.h>
 #include <asm/auxio.h>
+#include <asm/head.h>
 
 #ifdef CONFIG_SMP
 static void distribute_irqs(void);
@@ -153,7 +154,8 @@ void enable_irq(unsigned int irq)
 		unsigned long ver;
 
 		__asm__ ("rdpr %%ver, %0" : "=r" (ver));
-		if ((ver >> 32) == 0x003e0016) {
+		if ((ver >> 32) == __JALAPENO_ID ||
+		    (ver >> 32) == __SERRANO_ID) {
 			/* We set it to our JBUS ID. */
 			__asm__ __volatile__("ldxa [%%g0] %1, %0"
 					     : "=r" (tid)

arch/sparc64/kernel/setup.c

@@ -490,6 +490,58 @@ void register_prom_callbacks(void)
 		   "' linux-.soft2 to .soft2");
 }
 
+static void __init per_cpu_patch(void)
+{
+#ifdef CONFIG_SMP
+	struct cpuid_patch_entry *p;
+	unsigned long ver;
+	int is_jbus;
+
+	if (tlb_type == spitfire && !this_is_starfire)
+		return;
+
+	__asm__ ("rdpr %%ver, %0" : "=r" (ver));
+	is_jbus = ((ver >> 32) == __JALAPENO_ID ||
+		   (ver >> 32) == __SERRANO_ID);
+
+	p = &__cpuid_patch;
+	while (p < &__cpuid_patch_end) {
+		unsigned long addr = p->addr;
+		unsigned int *insns;
+
+		switch (tlb_type) {
+		case spitfire:
+			insns = &p->starfire[0];
+			break;
+		case cheetah:
+		case cheetah_plus:
+			if (is_jbus)
+				insns = &p->cheetah_jbus[0];
+			else
+				insns = &p->cheetah_safari[0];
+			break;
+		default:
+			prom_printf("Unknown cpu type, halting.\n");
+			prom_halt();
+		};
+
+		*(unsigned int *) (addr +  0) = insns[0];
+		__asm__ __volatile__("flush	%0" : : "r" (addr +  0));
+
+		*(unsigned int *) (addr +  4) = insns[1];
+		__asm__ __volatile__("flush	%0" : : "r" (addr +  4));
+
+		*(unsigned int *) (addr +  8) = insns[2];
+		__asm__ __volatile__("flush	%0" : : "r" (addr +  8));
+
+		*(unsigned int *) (addr + 12) = insns[3];
+		__asm__ __volatile__("flush	%0" : : "r" (addr + 12));
+
+		p++;
+	}
+#endif
+}
+
 void __init setup_arch(char **cmdline_p)
 {
 	/* Initialize PROM console and command line. */
@@ -507,8 +559,8 @@ void __init setup_arch(char **cmdline_p)
 	/* Work out if we are starfire early on */
 	check_if_starfire();
 
-	/* Now we know enough to patch the __get_cpu_id()
-	 * trampoline used by trap code.
+	/* Now we know enough to patch the get_cpuid sequences
+	 * used by trap code.
 	 */
 	per_cpu_patch();
 

arch/sparc64/kernel/smp.c

@@ -424,7 +424,7 @@ static __inline__ void spitfire_xcall_deliver(u64 data0, u64 data1, u64 data2, c
 static void cheetah_xcall_deliver(u64 data0, u64 data1, u64 data2, cpumask_t mask)
 {
 	u64 pstate, ver;
-	int nack_busy_id, is_jalapeno;
+	int nack_busy_id, is_jbus;
 
 	if (cpus_empty(mask))
 		return;
@@ -434,7 +434,8 @@ static void cheetah_xcall_deliver(u64 data0, u64 data1, u64 data2, cpumask_t mas
 	 * derivative processor.
 	 */
 	__asm__ ("rdpr %%ver, %0" : "=r" (ver));
-	is_jalapeno = ((ver >> 32) == 0x003e0016);
+	is_jbus = ((ver >> 32) == __JALAPENO_ID ||
+		   (ver >> 32) == __SERRANO_ID);
 
 	__asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate));
 
@@ -459,7 +460,7 @@ static void cheetah_xcall_deliver(u64 data0, u64 data1, u64 data2, cpumask_t mas
 		for_each_cpu_mask(i, mask) {
 			u64 target = (i << 14) | 0x70;
 
-			if (!is_jalapeno)
+			if (!is_jbus)
 				target |= (nack_busy_id << 24);
 			__asm__ __volatile__(
 				"stxa	%%g0, [%0] %1\n\t"
@@ -512,7 +513,7 @@ static void cheetah_xcall_deliver(u64 data0, u64 data1, u64 data2, cpumask_t mas
 			for_each_cpu_mask(i, mask) {
 				u64 check_mask;
 
-				if (is_jalapeno)
+				if (is_jbus)
 					check_mask = (0x2UL << (2*i));
 				else
 					check_mask = (0x2UL <<

arch/sparc64/kernel/traps.c

@@ -38,6 +38,7 @@
 #include <asm/processor.h>
 #include <asm/timer.h>
 #include <asm/kdebug.h>
+#include <asm/head.h>
 #ifdef CONFIG_KMOD
 #include <linux/kmod.h>
 #endif
@@ -788,7 +789,8 @@ void __init cheetah_ecache_flush_init(void)
 		cheetah_error_log[i].afsr = CHAFSR_INVALID;
 
 	__asm__ ("rdpr %%ver, %0" : "=r" (ver));
-	if ((ver >> 32) == 0x003e0016) {
+	if ((ver >> 32) == __JALAPENO_ID ||
+	    (ver >> 32) == __SERRANO_ID) {
 		cheetah_error_table = &__jalapeno_error_table[0];
 		cheetah_afsr_errors = JPAFSR_ERRORS;
 	} else if ((ver >> 32) == 0x003e0015) {

arch/sparc64/kernel/vmlinux.lds.S

@@ -74,6 +74,9 @@ SECTIONS
   __tsb_phys_patch = .;
   .tsb_phys_patch : { *(.tsb_phys_patch) }
   __tsb_phys_patch_end = .;
+  __cpuid_patch = .;
+  .cpuid_patch : { *(.cpuid_patch) }
+  __cpuid_patch_end = .;
   . = ALIGN(8192); 
   __initramfs_start = .;
   .init.ramfs : { *(.init.ramfs) }

include/asm-sparc64/cpudata.h

@@ -60,9 +60,18 @@ struct trap_per_cpu {
 } __attribute__((aligned(64)));
 extern struct trap_per_cpu trap_block[NR_CPUS];
 extern void init_cur_cpu_trap(void);
-extern void per_cpu_patch(void);
 extern void setup_tba(void);
 
+#ifdef CONFIG_SMP
+struct cpuid_patch_entry {
+	unsigned int	addr;
+	unsigned int	cheetah_safari[4];
+	unsigned int	cheetah_jbus[4];
+	unsigned int	starfire[4];
+};
+extern struct cpuid_patch_entry __cpuid_patch, __cpuid_patch_end;
+#endif
+
 #endif /* !(__ASSEMBLY__) */
 
 #define TRAP_PER_CPU_THREAD	0x00
@@ -70,35 +79,58 @@ extern void setup_tba(void);
 
 #define TRAP_BLOCK_SZ_SHIFT	6
 
-/* Clobbers %g1, loads %g6 with local processor's cpuid */
-#define __GET_CPUID			\
-	ba,pt	%xcc, __get_cpu_id;	\
-	 rd	%pc, %g1;
+#ifdef CONFIG_SMP
+
+#define __GET_CPUID(REG)				\
+	/* Spitfire implementation (default). */	\
+661:	ldxa		[%g0] ASI_UPA_CONFIG, REG;	\
+	srlx		REG, 17, REG;			\
+	 and		REG, 0x1f, REG;			\
+	nop;						\
+	.section	.cpuid_patch, "ax";		\
+	/* Instruction location. */			\
+	.word		661b;				\
+	/* Cheetah Safari implementation. */		\
+	ldxa		[%g0] ASI_SAFARI_CONFIG, REG;	\
+	srlx		REG, 17, REG;			\
+	and		REG, 0x3ff, REG;		\
+	nop;						\
+	/* Cheetah JBUS implementation. */		\
+	ldxa		[%g0] ASI_JBUS_CONFIG, REG;	\
+	srlx		REG, 17, REG;			\
+	and		REG, 0x1f, REG;			\
+	nop;						\
+	/* Starfire implementation. */			\
+	sethi		%hi(0x1fff40000d0 >> 9), REG;	\
+	sllx		REG, 9, REG;			\
+	or		REG, 0xd0, REG;			\
+	lduwa		[REG] ASI_PHYS_BYPASS_EC_E, REG;\
+	.previous;
 
 /* Clobbers %g1, current address space PGD phys address into %g7.  */
 #define TRAP_LOAD_PGD_PHYS			\
-	__GET_CPUID				\
-	sllx	%g6, TRAP_BLOCK_SZ_SHIFT, %g6;	\
+	__GET_CPUID(%g1)			\
 	sethi	%hi(trap_block), %g7;		\
+	sllx	%g1, TRAP_BLOCK_SZ_SHIFT, %g1;	\
 	or	%g7, %lo(trap_block), %g7;	\
-	add	%g7, %g6, %g7;			\
+	add	%g7, %g1, %g7;			\
 	ldx	[%g7 + TRAP_PER_CPU_PGD_PADDR], %g7;
 
 /* Clobbers %g1, loads local processor's IRQ work area into %g6.  */
 #define TRAP_LOAD_IRQ_WORK			\
-	__GET_CPUID				\
-	sethi	%hi(__irq_work), %g1;		\
-	sllx	%g6, 6, %g6;			\
-	or	%g1, %lo(__irq_work), %g1;	\
-	add	%g1, %g6, %g6;
+	__GET_CPUID(%g1)			\
+	sethi	%hi(__irq_work), %g6;		\
+	sllx	%g1, 6, %g1;			\
+	or	%g6, %lo(__irq_work), %g6;	\
+	add	%g6, %g1, %g6;
 
 /* Clobbers %g1, loads %g6 with current thread info pointer.  */
 #define TRAP_LOAD_THREAD_REG			\
-	__GET_CPUID				\
-	sllx	%g6, TRAP_BLOCK_SZ_SHIFT, %g6;	\
-	sethi	%hi(trap_block), %g1;		\
-	or	%g1, %lo(trap_block), %g1;	\
-	ldx	[%g1 + %g6], %g6;
+	__GET_CPUID(%g1)			\
+	sethi	%hi(trap_block), %g6;		\
+	sllx	%g1, TRAP_BLOCK_SZ_SHIFT, %g1;	\
+	or	%g6, %lo(trap_block), %g6;	\
+	ldx	[%g6 + %g1], %g6;
 
 /* Given the current thread info pointer in %g6, load the per-cpu
  * area base of the current processor into %g5.  REG1, REG2, and REG3 are
@@ -109,7 +141,6 @@ extern void setup_tba(void);
  * trap will load the fully resolved %g5 per-cpu base.  This can corrupt
  * the calculations done by the macro mid-stream.
  */
-#ifdef CONFIG_SMP
 #define LOAD_PER_CPU_BASE(REG1, REG2, REG3)		\
 	ldub	[%g6 + TI_CPU], REG1;			\
 	sethi	%hi(__per_cpu_shift), REG3;		\
@@ -118,8 +149,26 @@ extern void setup_tba(void);
 	ldx	[REG2 + %lo(__per_cpu_base)], REG2;	\
 	sllx	REG1, REG3, REG3;			\
 	add	REG3, REG2, %g5;
+
 #else
+
+/* Uniprocessor versions, we know the cpuid is zero.  */
+#define TRAP_LOAD_PGD_PHYS			\
+	sethi	%hi(trap_block), %g7;		\
+	or	%g7, %lo(trap_block), %g7;	\
+	ldx	[%g7 + TRAP_PER_CPU_PGD_PADDR], %g7;
+
+#define TRAP_LOAD_IRQ_WORK			\
+	sethi	%hi(__irq_work), %g6;		\
+	or	%g6, %lo(__irq_work), %g6;
+
+#define TRAP_LOAD_THREAD_REG			\
+	sethi	%hi(trap_block), %g6;		\
+	ldx	[%g6 + %lo(trap_block)], %g6;
+
+/* No per-cpu areas on uniprocessor, so no need to load %g5.  */
 #define LOAD_PER_CPU_BASE(REG1, REG2, REG3)
-#endif
+
+#endif /* !(CONFIG_SMP) */
 
 #endif /* _SPARC64_CPUDATA_H */

include/asm-sparc64/head.h

@@ -10,6 +10,7 @@
 
 #define __CHEETAH_ID	0x003e0014
 #define __JALAPENO_ID	0x003e0016
+#define __SERRANO_ID	0x003e0022
 
 #define CHEETAH_MANUF		0x003e
 #define CHEETAH_IMPL		0x0014 /* Ultra-III   */

include/asm-sparc64/smp.h

@@ -37,33 +37,7 @@ extern cpumask_t phys_cpu_present_map;
  *	General functions that each host system must provide.
  */
 
-static __inline__ int hard_smp_processor_id(void)
-{
-	if (tlb_type == cheetah || tlb_type == cheetah_plus) {
-		unsigned long cfg, ver;
-		__asm__ __volatile__("rdpr %%ver, %0" : "=r" (ver));
-		if ((ver >> 32) == 0x003e0016) {
-			__asm__ __volatile__("ldxa [%%g0] %1, %0"
-					     : "=r" (cfg)
-					     : "i" (ASI_JBUS_CONFIG));
-			return ((cfg >> 17) & 0x1f);
-		} else {
-			__asm__ __volatile__("ldxa [%%g0] %1, %0"
-					     : "=r" (cfg)
-					     : "i" (ASI_SAFARI_CONFIG));
-			return ((cfg >> 17) & 0x3ff);
-		}
-	} else if (this_is_starfire != 0) {
-		return starfire_hard_smp_processor_id();
-	} else {
-		unsigned long upaconfig;
-		__asm__ __volatile__("ldxa	[%%g0] %1, %0"
-				     : "=r" (upaconfig)
-				     : "i" (ASI_UPA_CONFIG));
-		return ((upaconfig >> 17) & 0x1f);
-	}
-}
-
+extern int hard_smp_processor_id(void);
 #define raw_smp_processor_id() (current_thread_info()->cpu)
 
 extern void smp_setup_cpu_possible_map(void);