x86: pass in cpu number to switch_to_new_gdt()

Impact: cleanup, prepare for xen boot fix.

Xen needs to call this function very early to setup the GDT and
per-cpu segments.  Remove the call to smp_processor_id() and just
pass in the cpu number.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

3 files changed, 5 insertions, 6 deletions

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 652fdc9a757a..6eacd64b602e 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -255,10 +255,9 @@ __u32 cleared_cpu_caps[NCAPINTS] __cpuinitdata;
 
 /* Current gdt points %fs at the "master" per-cpu area: after this,
  * it's on the real one. */
-void switch_to_new_gdt(void)
+void switch_to_new_gdt(int cpu)
 {
         struct desc_ptr gdt_descr;
-        int cpu = smp_processor_id();
 
         gdt_descr.address = (long)get_cpu_gdt_table(cpu);
         gdt_descr.size = GDT_SIZE - 1;
@@ -993,7 +992,7 @@ void __cpuinit cpu_init(void)
          * and set up the GDT descriptor:
          */
 
-        switch_to_new_gdt();
+        switch_to_new_gdt(cpu);
         loadsegment(fs, 0);
 
         load_idt((const struct desc_ptr *)&idt_descr);
@@ -1098,7 +1097,7 @@ void __cpuinit cpu_init(void)
                 clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
 
         load_idt(&idt_descr);
-        switch_to_new_gdt();
+        switch_to_new_gdt(cpu);
 
         /*
          * Set up and load the per-CPU TSS and LDT
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index 0d1e7ac439f4..ef91747bbed5 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -122,7 +122,7 @@ void __init setup_per_cpu_areas(void)
                  * area.  Reload any changed state for the boot CPU.
                  */
                 if (cpu == boot_cpu_id)
-                        switch_to_new_gdt();
+                        switch_to_new_gdt(cpu);
 
                 DBG("PERCPU: cpu %4d %p\n", cpu, ptr);
         }
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index f9dbcff43546..612d3c74f6a3 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1185,7 +1185,7 @@ out:
 void __init native_smp_prepare_boot_cpu(void)
 {
         int me = smp_processor_id();
-        switch_to_new_gdt();
+        switch_to_new_gdt(me);
         /* already set me in cpu_online_mask in boot_cpu_init() */
         cpumask_set_cpu(me, cpu_callout_mask);
         per_cpu(cpu_state, me) = CPU_ONLINE;