x86: reduce stack usage in init_intel_cacheinfo

Impact: reduce stack usage.

init_intel_cacheinfo() does not use the cpumask so define a subset
of struct _cpuid4_info (_cpuid4_info_regs) that can be used instead.
Signed-off-by: Mike Travis <travis@sgi.com>

arch/x86/kernel/cpu/intel_cacheinfo.c

@@ -132,7 +132,16 @@ struct _cpuid4_info {
 	union _cpuid4_leaf_ecx ecx;
 	unsigned long size;
 	unsigned long can_disable;
-	cpumask_t shared_cpu_map;	/* future?: only cpus/node is needed */
+	DECLARE_BITMAP(shared_cpu_map, NR_CPUS);
+};
+
+/* subset of above _cpuid4_info w/o shared_cpu_map */
+struct _cpuid4_info_regs {
+	union _cpuid4_leaf_eax eax;
+	union _cpuid4_leaf_ebx ebx;
+	union _cpuid4_leaf_ecx ecx;
+	unsigned long size;
+	unsigned long can_disable;
 };
 
 #ifdef CONFIG_PCI
@@ -263,7 +272,7 @@ amd_cpuid4(int leaf, union _cpuid4_leaf_eax *eax,
 }
 
 static void __cpuinit
-amd_check_l3_disable(int index, struct _cpuid4_info *this_leaf)
+amd_check_l3_disable(int index, struct _cpuid4_info_regs *this_leaf)
 {
 	if (index < 3)
 		return;
@@ -271,7 +280,8 @@ amd_check_l3_disable(int index, struct _cpuid4_info *this_leaf)
 }
 
 static int
-__cpuinit cpuid4_cache_lookup(int index, struct _cpuid4_info *this_leaf)
+__cpuinit cpuid4_cache_lookup_regs(int index,
+				   struct _cpuid4_info_regs *this_leaf)
 {
 	union _cpuid4_leaf_eax 	eax;
 	union _cpuid4_leaf_ebx 	ebx;
@@ -299,6 +309,15 @@ __cpuinit cpuid4_cache_lookup(int index, struct _cpuid4_info *this_leaf)
 	return 0;
 }
 
+static int
+__cpuinit cpuid4_cache_lookup(int index, struct _cpuid4_info *this_leaf)
+{
+	struct _cpuid4_info_regs *leaf_regs =
+		(struct _cpuid4_info_regs *)this_leaf;
+
+	return cpuid4_cache_lookup_regs(index, leaf_regs);
+}
+
 static int __cpuinit find_num_cache_leaves(void)
 {
 	unsigned int		eax, ebx, ecx, edx;
@@ -338,11 +357,10 @@ unsigned int __cpuinit init_intel_cacheinfo(struct cpuinfo_x86 *c)
 		 * parameters cpuid leaf to find the cache details
 		 */
 		for (i = 0; i < num_cache_leaves; i++) {
-			struct _cpuid4_info this_leaf;
-
+			struct _cpuid4_info_regs this_leaf;
 			int retval;
 
-			retval = cpuid4_cache_lookup(i, &this_leaf);
+			retval = cpuid4_cache_lookup_regs(i, &this_leaf);
 			if (retval >= 0) {
 				switch(this_leaf.eax.split.level) {
 				    case 1:
@@ -491,17 +509,20 @@ static void __cpuinit cache_shared_cpu_map_setup(unsigned int cpu, int index)
 	num_threads_sharing = 1 + this_leaf->eax.split.num_threads_sharing;
 
 	if (num_threads_sharing == 1)
-		cpu_set(cpu, this_leaf->shared_cpu_map);
+		cpumask_set_cpu(cpu, to_cpumask(this_leaf->shared_cpu_map));
 	else {
 		index_msb = get_count_order(num_threads_sharing);
 
 		for_each_online_cpu(i) {
 			if (cpu_data(i).apicid >> index_msb ==
 			    c->apicid >> index_msb) {
-				cpu_set(i, this_leaf->shared_cpu_map);
+				cpumask_set_cpu(i,
+					to_cpumask(this_leaf->shared_cpu_map));
 				if (i != cpu && per_cpu(cpuid4_info, i))  {
-					sibling_leaf = CPUID4_INFO_IDX(i, index);
-					cpu_set(cpu, sibling_leaf->shared_cpu_map);
+					sibling_leaf =
+						CPUID4_INFO_IDX(i, index);
+					cpumask_set_cpu(cpu, to_cpumask(
+						sibling_leaf->shared_cpu_map));
 				}
 			}
 		}
@@ -513,9 +534,10 @@ static void __cpuinit cache_remove_shared_cpu_map(unsigned int cpu, int index)
 	int sibling;
 
 	this_leaf = CPUID4_INFO_IDX(cpu, index);
-	for_each_cpu_mask_nr(sibling, this_leaf->shared_cpu_map) {
+	for_each_cpu(sibling, to_cpumask(this_leaf->shared_cpu_map)) {
 		sibling_leaf = CPUID4_INFO_IDX(sibling, index);
-		cpu_clear(cpu, sibling_leaf->shared_cpu_map);
+		cpumask_clear_cpu(cpu,
+				  to_cpumask(sibling_leaf->shared_cpu_map));
 	}
 }
 #else
@@ -620,8 +642,9 @@ static ssize_t show_shared_cpu_map_func(struct _cpuid4_info *this_leaf,
 	int n = 0;
 
 	if (len > 1) {
-		cpumask_t *mask = &this_leaf->shared_cpu_map;
+		const struct cpumask *mask;
 
+		mask = to_cpumask(this_leaf->shared_cpu_map);
 		n = type?
 			cpulist_scnprintf(buf, len-2, mask) :
 			cpumask_scnprintf(buf, len-2, mask);
@@ -684,7 +707,8 @@ static struct pci_dev *get_k8_northbridge(int node)
 
 static ssize_t show_cache_disable(struct _cpuid4_info *this_leaf, char *buf)
 {
-	int node = cpu_to_node(first_cpu(this_leaf->shared_cpu_map));
+	const struct cpumask *mask = to_cpumask(this_leaf->shared_cpu_map);
+	int node = cpu_to_node(cpumask_first(mask));
 	struct pci_dev *dev = NULL;
 	ssize_t ret = 0;
 	int i;
@@ -718,7 +742,8 @@ static ssize_t
 store_cache_disable(struct _cpuid4_info *this_leaf, const char *buf,
 		    size_t count)
 {
-	int node = cpu_to_node(first_cpu(this_leaf->shared_cpu_map));
+	const struct cpumask *mask = to_cpumask(this_leaf->shared_cpu_map);
+	int node = cpu_to_node(cpumask_first(mask));
 	struct pci_dev *dev = NULL;
 	unsigned int ret, index, val;
 
@@ -863,7 +888,7 @@ static int __cpuinit cpuid4_cache_sysfs_init(unsigned int cpu)
 	return -ENOMEM;
 }
 
-static cpumask_t cache_dev_map = CPU_MASK_NONE;
+static DECLARE_BITMAP(cache_dev_map, NR_CPUS);
 
 /* Add/Remove cache interface for CPU device */
 static int __cpuinit cache_add_dev(struct sys_device * sys_dev)
@@ -903,7 +928,7 @@ static int __cpuinit cache_add_dev(struct sys_device * sys_dev)
 		}
 		kobject_uevent(&(this_object->kobj), KOBJ_ADD);
 	}
-	cpu_set(cpu, cache_dev_map);
+	cpumask_set_cpu(cpu, to_cpumask(cache_dev_map));
 
 	kobject_uevent(per_cpu(cache_kobject, cpu), KOBJ_ADD);
 	return 0;
@@ -916,9 +941,9 @@ static void __cpuinit cache_remove_dev(struct sys_device * sys_dev)
 
 	if (per_cpu(cpuid4_info, cpu) == NULL)
 		return;
-	if (!cpu_isset(cpu, cache_dev_map))
+	if (!cpumask_test_cpu(cpu, to_cpumask(cache_dev_map)))
 		return;
-	cpu_clear(cpu, cache_dev_map);
+	cpumask_clear_cpu(cpu, to_cpumask(cache_dev_map));
 
 	for (i = 0; i < num_cache_leaves; i++)
 		kobject_put(&(INDEX_KOBJECT_PTR(cpu,i)->kobj));