x86: misc clean up after the percpu update

Do the following cleanups:

* kill x86_64_init_pda() which now is equivalent to pda_init()

* use per_cpu_offset() instead of cpu_pda() when initializing
  initial_gs
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/include/asm/setup.h

@@ -100,7 +100,6 @@ extern unsigned long init_pg_tables_start;
 extern unsigned long init_pg_tables_end;
 
 #else
-void __init x86_64_init_pda(void);
 void __init x86_64_start_kernel(char *real_mode);
 void __init x86_64_start_reservations(char *real_mode_data);
 

arch/x86/kernel/acpi/sleep.c

@@ -101,7 +101,7 @@ int acpi_save_state_mem(void)
 	stack_start.sp = temp_stack + sizeof(temp_stack);
 	early_gdt_descr.address =
 			(unsigned long)get_cpu_gdt_table(smp_processor_id());
-	initial_gs = (unsigned long)cpu_pda(smp_processor_id());
+	initial_gs = per_cpu_offset(smp_processor_id());
 #endif
 	initial_code = (unsigned long)wakeup_long64;
 	saved_magic = 0x123456789abcdef0;

arch/x86/kernel/head64.c

@@ -26,11 +26,6 @@
 #include <asm/bios_ebda.h>
 #include <asm/trampoline.h>
 
-void __init x86_64_init_pda(void)
-{
-	pda_init(0);
-}
-
 static void __init zap_identity_mappings(void)
 {
 	pgd_t *pgd = pgd_offset_k(0UL);
@@ -96,7 +91,7 @@ void __init x86_64_start_kernel(char * real_mode_data)
 	if (console_loglevel == 10)
 		early_printk("Kernel alive\n");
 
-	x86_64_init_pda();
+	pda_init(0);
 
 	x86_64_start_reservations(real_mode_data);
 }

arch/x86/kernel/smpboot.c

@@ -798,7 +798,7 @@ static int __cpuinit do_boot_cpu(int apicid, int cpu)
 #else
 	cpu_pda(cpu)->pcurrent = c_idle.idle;
 	clear_tsk_thread_flag(c_idle.idle, TIF_FORK);
-	initial_gs = (unsigned long)cpu_pda(cpu);
+	initial_gs = per_cpu_offset(cpu);
 #endif
 	early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
 	initial_code = (unsigned long)start_secondary;

arch/x86/xen/enlighten.c

@@ -1645,7 +1645,7 @@ asmlinkage void __init xen_start_kernel(void)
 #ifdef CONFIG_X86_64
 	/* Disable until direct per-cpu data access. */
 	have_vcpu_info_placement = 0;
-	x86_64_init_pda();
+	pda_init(0);
 #endif
 
 	xen_smp_init();