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, 13 insertions, 7 deletions

diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index 94630c66470e..0f0d9d4a6650 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -534,7 +534,7 @@ static void __init amd_detect_cmp(struct cpuinfo_x86 *c)
                    but in the same order as the HT nodeids.
                    If that doesn't result in a usable node fall back to the
                    path for the previous case.  */
-                int ht_nodeid = apicid - (cpu_data[0].phys_proc_id << bits);
+                int ht_nodeid = apicid - (cpu_data(0).phys_proc_id << bits);
                 if (ht_nodeid >= 0 &&
                     apicid_to_node[ht_nodeid] != NUMA_NO_NODE)
                         node = apicid_to_node[ht_nodeid];
@@ -858,6 +858,7 @@ void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c)
 
 #ifdef CONFIG_SMP
         c->phys_proc_id = (cpuid_ebx(1) >> 24) & 0xff;
+        c->cpu_index = 0;
 #endif
 }
 
@@ -964,6 +965,7 @@ void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
 static int show_cpuinfo(struct seq_file *m, void *v)
 {
         struct cpuinfo_x86 *c = v;
+        int cpu = 0;
 
         /* 
          * These flag bits must match the definitions in <asm/cpufeature.h>.
@@ -1042,8 +1044,9 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 
 
 #ifdef CONFIG_SMP
-        if (!cpu_online(c-cpu_data))
+        if (!cpu_online(c->cpu_index))
                 return 0;
+        cpu = c->cpu_index;
 #endif
 
         seq_printf(m,"processor\t: %u\n"
@@ -1051,7 +1054,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
                      "cpu family\t: %d\n"
                      "model\t\t: %d\n"
                      "model name\t: %s\n",
-                     (unsigned)(c-cpu_data),
+                     (unsigned)cpu,
                      c->x86_vendor_id[0] ? c->x86_vendor_id : "unknown",
                      c->x86,
                      (int)c->x86_model,
@@ -1063,7 +1066,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
                 seq_printf(m, "stepping\t: unknown\n");
         
         if (cpu_has(c,X86_FEATURE_TSC)) {
-                unsigned int freq = cpufreq_quick_get((unsigned)(c-cpu_data));
+                unsigned int freq = cpufreq_quick_get((unsigned)cpu);
                 if (!freq)
                         freq = cpu_khz;
                 seq_printf(m, "cpu MHz\t\t: %u.%03u\n",
@@ -1076,7 +1079,6 @@ static int show_cpuinfo(struct seq_file *m, void *v)
         
 #ifdef CONFIG_SMP
         if (smp_num_siblings * c->x86_max_cores > 1) {
-                int cpu = c - cpu_data;
                 seq_printf(m, "physical id\t: %d\n", c->phys_proc_id);
                 seq_printf(m, "siblings\t: %d\n",
                                cpus_weight(per_cpu(cpu_core_map, cpu)));
@@ -1134,12 +1136,16 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 
 static void *c_start(struct seq_file *m, loff_t *pos)
 {
-        return *pos < NR_CPUS ? cpu_data + *pos : NULL;
+        if (*pos == 0)  /* just in case, cpu 0 is not the first */
+                *pos = first_cpu(cpu_possible_map);
+        if ((*pos) < NR_CPUS && cpu_possible(*pos))
+                return &cpu_data(*pos);
+        return NULL;
 }
 
 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 {
-        ++*pos;
+        *pos = next_cpu(*pos, cpu_possible_map);
         return c_start(m, pos);
 }