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);
 }