[PATCH] i386: Implement smp_processor_id() with the PDA

Use the cpu_number in the PDA to implement raw_smp_processor_id.  This is a
little simpler than using thread_info, though the cpu field in thread_info
cannot be removed since it is used for things other than getting the current
CPU in common code.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>

2 files changed, 4 insertions, 1 deletions

diff --git a/include/asm-i386/pda.h b/include/asm-i386/pda.h
index 4c39ccb1305c..f90fde22566d 100644
--- a/include/asm-i386/pda.h
+++ b/include/asm-i386/pda.h
@@ -11,6 +11,8 @@
 struct i386_pda
 {
         struct i386_pda *_pda;          /* pointer to self */
+
+        int cpu_number;
 };
 
 extern struct i386_pda *_cpu_pda[];
diff --git a/include/asm-i386/smp.h b/include/asm-i386/smp.h
index bd59c1508e71..64fe624c02ca 100644
--- a/include/asm-i386/smp.h
+++ b/include/asm-i386/smp.h
@@ -8,6 +8,7 @@
 #include <linux/kernel.h>
 #include <linux/threads.h>
 #include <linux/cpumask.h>
+#include <asm/pda.h>
 #endif
 
 #ifdef CONFIG_X86_LOCAL_APIC
@@ -56,7 +57,7 @@ extern void cpu_uninit(void);
  * from the initial startup. We map APIC_BASE very early in page_setup(),
  * so this is correct in the x86 case.
  */
-#define raw_smp_processor_id() (current_thread_info()->cpu)
+#define raw_smp_processor_id() (read_pda(cpu_number))
 
 extern cpumask_t cpu_callout_map;
 extern cpumask_t cpu_callin_map;