[PATCH] percpu: init_tss

Use the percpu infrastructure rather than open-coded array[NR_CPUS].
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/i386/kernel/cpu/common.c

@@ -506,7 +506,7 @@ void __init early_cpu_init(void)
 void __init cpu_init (void)
 {
 	int cpu = smp_processor_id();
-	struct tss_struct * t = init_tss + cpu;
+	struct tss_struct * t = &per_cpu(init_tss, cpu);
 	struct thread_struct *thread = &current->thread;
 
 	if (test_and_set_bit(cpu, &cpu_initialized)) {

arch/i386/kernel/init_task.c

@@ -40,10 +40,7 @@ EXPORT_SYMBOL(init_task);
 
 /*
  * per-CPU TSS segments. Threads are completely 'soft' on Linux,
- * no more per-task TSS's. The TSS size is kept cacheline-aligned
- * so they are allowed to end up in the .data.cacheline_aligned
- * section. Since TSS's are completely CPU-local, we want them
- * on exact cacheline boundaries, to eliminate cacheline ping-pong.
+ * no more per-task TSS's.
  */ 
-struct tss_struct init_tss[NR_CPUS] __cacheline_aligned = { [0 ... NR_CPUS-1] = INIT_TSS };
+DEFINE_PER_CPU(struct tss_struct, init_tss) ____cacheline_maxaligned_in_smp = INIT_TSS;
 

arch/i386/kernel/ioport.c

@@ -87,7 +87,7 @@ asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on)
 	 * because the ->io_bitmap_max value must match the bitmap
 	 * contents:
 	 */
-	tss = init_tss + get_cpu();
+	tss = &per_cpu(init_tss, get_cpu());
 
 	set_bitmap(t->io_bitmap_ptr, from, num, !turn_on);
 

arch/i386/kernel/process.c

@@ -299,7 +299,7 @@ void exit_thread(void)
 	/* The process may have allocated an io port bitmap... nuke it. */
 	if (unlikely(NULL != t->io_bitmap_ptr)) {
 		int cpu = get_cpu();
-		struct tss_struct *tss = init_tss + cpu;
+		struct tss_struct *tss = &per_cpu(init_tss, cpu);
 
 		kfree(t->io_bitmap_ptr);
 		t->io_bitmap_ptr = NULL;
@@ -517,7 +517,7 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas
 	struct thread_struct *prev = &prev_p->thread,
 				 *next = &next_p->thread;
 	int cpu = smp_processor_id();
-	struct tss_struct *tss = init_tss + cpu;
+	struct tss_struct *tss = &per_cpu(init_tss, cpu);
 
 	/* never put a printk in __switch_to... printk() calls wake_up*() indirectly */
 

arch/i386/kernel/sysenter.c

@@ -24,7 +24,7 @@ extern asmlinkage void sysenter_entry(void);
 void enable_sep_cpu(void *info)
 {
 	int cpu = get_cpu();
-	struct tss_struct *tss = init_tss + cpu;
+	struct tss_struct *tss = &per_cpu(init_tss, cpu);
 
 	tss->ss1 = __KERNEL_CS;
 	tss->esp1 = sizeof(struct tss_struct) + (unsigned long) tss;

arch/i386/kernel/vm86.c

@@ -121,7 +121,7 @@ struct pt_regs * fastcall save_v86_state(struct kernel_vm86_regs * regs)
 		do_exit(SIGSEGV);
 	}
 
-	tss = init_tss + get_cpu();
+	tss = &per_cpu(init_tss, get_cpu());
 	current->thread.esp0 = current->thread.saved_esp0;
 	current->thread.sysenter_cs = __KERNEL_CS;
 	load_esp0(tss, &current->thread);
@@ -303,7 +303,7 @@ static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk
 	asm volatile("movl %%fs,%0":"=m" (tsk->thread.saved_fs));
 	asm volatile("movl %%gs,%0":"=m" (tsk->thread.saved_gs));
 
-	tss = init_tss + get_cpu();
+	tss = &per_cpu(init_tss, get_cpu());
 	tsk->thread.esp0 = (unsigned long) &info->VM86_TSS_ESP0;
 	if (cpu_has_sep)
 		tsk->thread.sysenter_cs = 0;

arch/i386/power/cpu.c

@@ -83,7 +83,7 @@ do_fpu_end(void)
 static void fix_processor_context(void)
 {
 	int cpu = smp_processor_id();
-	struct tss_struct * t = init_tss + cpu;
+	struct tss_struct * t = &per_cpu(init_tss, cpu);
 
 	set_tss_desc(cpu,t);	/* This just modifies memory; should not be necessary. But... This is necessary, because 386 hardware has concept of busy TSS or some similar stupidity. */
         per_cpu(cpu_gdt_table, cpu)[GDT_ENTRY_TSS].b &= 0xfffffdff;

include/asm-i386/processor.h

@@ -19,6 +19,7 @@
 #include <linux/cache.h>
 #include <linux/config.h>
 #include <linux/threads.h>
+#include <asm/percpu.h>
 
 /* flag for disabling the tsc */
 extern int tsc_disable;
@@ -84,8 +85,8 @@ struct cpuinfo_x86 {
 
 extern struct cpuinfo_x86 boot_cpu_data;
 extern struct cpuinfo_x86 new_cpu_data;
-extern struct tss_struct init_tss[NR_CPUS];
 extern struct tss_struct doublefault_tss;
+DECLARE_PER_CPU(struct tss_struct, init_tss);
 
 #ifdef CONFIG_SMP
 extern struct cpuinfo_x86 cpu_data[];
@@ -441,7 +442,6 @@ struct thread_struct {
 #define INIT_TSS  {							\
 	.esp0		= sizeof(init_stack) + (long)&init_stack,	\
 	.ss0		= __KERNEL_DS,					\
-	.esp1		= sizeof(init_tss[0]) + (long)&init_tss[0],	\
 	.ss1		= __KERNEL_CS,					\
 	.ldt		= GDT_ENTRY_LDT,				\
 	.io_bitmap_base	= offsetof(struct tss_struct,io_bitmap),	\