x86: convert cpuinfo_x86 array to a per_cpu array

cpu_data is currently an array defined using NR_CPUS.  This means that
we overallocate since we will rarely really use maximum configured cpus.
When NR_CPU count is raised to 4096 the size of cpu_data becomes
3,145,728 bytes.

These changes were adopted from the sparc64 (and ia64) code.  An
additional field was added to cpuinfo_x86 to be a non-ambiguous cpu
index.  This corresponds to the index into a cpumask_t as well as the
per_cpu index.  It's used in various places like show_cpuinfo().

cpu_data is defined to be the boot_cpu_data structure for the NON-SMP
case.

Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Mark M. Hoffman <mhoffman@lightlink.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 6 insertions, 4 deletions

diff --git a/include/asm-x86/processor_32.h b/include/asm-x86/processor_32.h
index 565b6fc5f5b4..13976b086837 100644
--- a/include/asm-x86/processor_32.h
+++ b/include/asm-x86/processor_32.h
@@ -79,6 +79,7 @@ struct cpuinfo_x86 {
         unsigned char booted_cores;     /* number of cores as seen by OS */
         __u8 phys_proc_id;              /* Physical processor id. */
         __u8 cpu_core_id;               /* Core id */
+        __u8 cpu_index;                 /* index into per_cpu list */
 #endif
 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
 
@@ -103,11 +104,12 @@ extern struct tss_struct doublefault_tss;
 DECLARE_PER_CPU(struct tss_struct, init_tss);
 
 #ifdef CONFIG_SMP
-extern struct cpuinfo_x86 cpu_data[];
-#define current_cpu_data cpu_data[smp_processor_id()]
+DECLARE_PER_CPU(struct cpuinfo_x86, cpu_info);
+#define cpu_data(cpu)           per_cpu(cpu_info, cpu)
+#define current_cpu_data        cpu_data(smp_processor_id())
 #else
-#define cpu_data (&boot_cpu_data)
-#define current_cpu_data boot_cpu_data
+#define cpu_data(cpu)           boot_cpu_data
+#define current_cpu_data        boot_cpu_data
 #endif
 
 /*