[SPARC64]: Add __read_mostly support.

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

arch/sparc64/kernel/smp.c

@@ -45,8 +45,8 @@ extern void calibrate_delay(void);
 /* Please don't make this stuff initdata!!!  --DaveM */
 static unsigned char boot_cpu_id;
 
-cpumask_t cpu_online_map = CPU_MASK_NONE;
-cpumask_t phys_cpu_present_map = CPU_MASK_NONE;
+cpumask_t cpu_online_map = CPU_MASK_NONE __read_mostly;
+cpumask_t phys_cpu_present_map = CPU_MASK_NONE __read_mostly;
 static cpumask_t smp_commenced_mask;
 static cpumask_t cpu_callout_map;
 
@@ -155,7 +155,7 @@ void cpu_panic(void)
 	panic("SMP bolixed\n");
 }
 
-static unsigned long current_tick_offset;
+static unsigned long current_tick_offset __read_mostly;
 
 /* This tick register synchronization scheme is taken entirely from
  * the ia64 port, see arch/ia64/kernel/smpboot.c for details and credit.
@@ -1193,8 +1193,8 @@ void smp_send_stop(void)
 {
 }
 
-unsigned long __per_cpu_base;
-unsigned long __per_cpu_shift;
+unsigned long __per_cpu_base __read_mostly;
+unsigned long __per_cpu_shift __read_mostly;
 
 EXPORT_SYMBOL(__per_cpu_base);
 EXPORT_SYMBOL(__per_cpu_shift);

arch/sparc64/kernel/time.c

@@ -73,7 +73,7 @@ static __initdata struct sparc64_tick_ops dummy_tick_ops = {
 	.get_tick	= dummy_get_tick,
 };
 
-struct sparc64_tick_ops *tick_ops = &dummy_tick_ops;
+struct sparc64_tick_ops *tick_ops __read_mostly = &dummy_tick_ops;
 
 #define TICK_PRIV_BIT	(1UL << 63)
 
@@ -195,7 +195,7 @@ static unsigned long tick_add_tick(unsigned long adj, unsigned long offset)
 	return new_tick;
 }
 
-static struct sparc64_tick_ops tick_operations = {
+static struct sparc64_tick_ops tick_operations __read_mostly = {
 	.init_tick	=	tick_init_tick,
 	.get_tick	=	tick_get_tick,
 	.get_compare	=	tick_get_compare,
@@ -276,7 +276,7 @@ static unsigned long stick_add_compare(unsigned long adj)
 	return new_compare;
 }
 
-static struct sparc64_tick_ops stick_operations = {
+static struct sparc64_tick_ops stick_operations __read_mostly = {
 	.init_tick	=	stick_init_tick,
 	.get_tick	=	stick_get_tick,
 	.get_compare	=	stick_get_compare,
@@ -422,7 +422,7 @@ static unsigned long hbtick_add_compare(unsigned long adj)
 	return val;
 }
 
-static struct sparc64_tick_ops hbtick_operations = {
+static struct sparc64_tick_ops hbtick_operations __read_mostly = {
 	.init_tick	=	hbtick_init_tick,
 	.get_tick	=	hbtick_get_tick,
 	.get_compare	=	hbtick_get_compare,
@@ -437,10 +437,9 @@ static struct sparc64_tick_ops hbtick_operations = {
  * NOTE: On SUN5 systems the ticker interrupt comes in using 2
  *       interrupts, one at level14 and one with softint bit 0.
  */
-unsigned long timer_tick_offset;
-unsigned long timer_tick_compare;
+unsigned long timer_tick_offset __read_mostly;
 
-static unsigned long timer_ticks_per_nsec_quotient;
+static unsigned long timer_ticks_per_nsec_quotient __read_mostly;
 
 #define TICK_SIZE (tick_nsec / 1000)
 
@@ -464,7 +463,7 @@ static inline void timer_check_rtc(void)
 
 static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs * regs)
 {
-	unsigned long ticks, pstate;
+	unsigned long ticks, compare, pstate;
 
 	write_seqlock(&xtime_lock);
 
@@ -483,14 +482,14 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs * regs)
 				     : "=r" (pstate)
 				     : "i" (PSTATE_IE));
 
-		timer_tick_compare = tick_ops->add_compare(timer_tick_offset);
+		compare = tick_ops->add_compare(timer_tick_offset);
 		ticks = tick_ops->get_tick();
 
 		/* Restore PSTATE_IE. */
 		__asm__ __volatile__("wrpr	%0, 0x0, %%pstate"
 				     : /* no outputs */
 				     : "r" (pstate));
-	} while (time_after_eq(ticks, timer_tick_compare));
+	} while (time_after_eq(ticks, compare));
 
 	timer_check_rtc();
 
@@ -506,11 +505,6 @@ void timer_tick_interrupt(struct pt_regs *regs)
 
 	do_timer(regs);
 
-	/*
-	 * Only keep timer_tick_offset uptodate, but don't set TICK_CMPR.
-	 */
-	timer_tick_compare = tick_ops->get_compare() + timer_tick_offset;
-
 	timer_check_rtc();
 
 	write_sequnlock(&xtime_lock);

arch/sparc64/kernel/vmlinux.lds.S

@@ -32,6 +32,8 @@ SECTIONS
   .data1   : { *(.data1) }
   . = ALIGN(64);
   .data.cacheline_aligned : { *(.data.cacheline_aligned) }
+  . = ALIGN(64);
+  .data.read_mostly : { *(.data.read_mostly) }
   _edata  =  .;
   PROVIDE (edata = .);
   .fixup   : { *(.fixup) }

include/linux/cache.h

@@ -13,7 +13,7 @@
 #define SMP_CACHE_BYTES L1_CACHE_BYTES
 #endif
 
-#ifdef CONFIG_X86
+#if defined(CONFIG_X86) || defined(CONFIG_SPARC64)
 #define __read_mostly __attribute__((__section__(".data.read_mostly")))
 #else
 #define __read_mostly