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Commit f9b90566 authored by Mike Travis's avatar Mike Travis Committed by Ingo Molnar
Browse files

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: default avatarMike Travis <travis@sgi.com>
parent a1c33bbe

arch/x86/kernel/cpu/intel_cacheinfo.c

+44 −19
Original line number Diff line number Diff line
@@ -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));