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[IA64] Export cpu cache info by sysfs
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The patch exports 8 attributes of cpu cache info under
/sys/devices/system/cpu/cpuX/cache/indexX:
1) level
2) type
3) coherency_line_size
4) ways_of_associativity
5) size
6) shared_cpu_map
7) attributes
8) number_of_sets: number_of_sets=size/ways_of_associativity/coherency_line_size.

Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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Zhang, Yanmin authored and Tony Luck committed Mar 31, 2006
1 parent d1127e4 commit f191800
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367 changes: 367 additions & 0 deletions arch/ia64/kernel/topology.c
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Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,8 @@
* 2002/08/07 Erich Focht <efocht@ess.nec.de>
* Populate cpu entries in sysfs for non-numa systems as well
* Intel Corporation - Ashok Raj
* 02/27/2006 Zhang, Yanmin
* Populate cpu cache entries in sysfs for cpu cache info
*/

#include <linux/config.h>
Expand All @@ -19,6 +21,7 @@
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/nodemask.h>
#include <linux/notifier.h>
#include <asm/mmzone.h>
#include <asm/numa.h>
#include <asm/cpu.h>
Expand Down Expand Up @@ -101,3 +104,367 @@ static int __init topology_init(void)
}

subsys_initcall(topology_init);


/*
* Export cpu cache information through sysfs
*/

/*
* A bunch of string array to get pretty printing
*/
static const char *cache_types[] = {
"", /* not used */
"Instruction",
"Data",
"Unified" /* unified */
};

static const char *cache_mattrib[]={
"WriteThrough",
"WriteBack",
"", /* reserved */
"" /* reserved */
};

struct cache_info {
pal_cache_config_info_t cci;
cpumask_t shared_cpu_map;
int level;
int type;
struct kobject kobj;
};

struct cpu_cache_info {
struct cache_info *cache_leaves;
int num_cache_leaves;
struct kobject kobj;
};

static struct cpu_cache_info all_cpu_cache_info[NR_CPUS];
#define LEAF_KOBJECT_PTR(x,y) (&all_cpu_cache_info[x].cache_leaves[y])

#ifdef CONFIG_SMP
static void cache_shared_cpu_map_setup( unsigned int cpu,
struct cache_info * this_leaf)
{
pal_cache_shared_info_t csi;
int num_shared, i = 0;
unsigned int j;

if (cpu_data(cpu)->threads_per_core <= 1 &&
cpu_data(cpu)->cores_per_socket <= 1) {
cpu_set(cpu, this_leaf->shared_cpu_map);
return;
}

if (ia64_pal_cache_shared_info(this_leaf->level,
this_leaf->type,
0,
&csi) != PAL_STATUS_SUCCESS)
return;

num_shared = (int) csi.num_shared;
do {
for_each_cpu(j)
if (cpu_data(cpu)->socket_id == cpu_data(j)->socket_id
&& cpu_data(j)->core_id == csi.log1_cid
&& cpu_data(j)->thread_id == csi.log1_tid)
cpu_set(j, this_leaf->shared_cpu_map);

i++;
} while (i < num_shared &&
ia64_pal_cache_shared_info(this_leaf->level,
this_leaf->type,
i,
&csi) == PAL_STATUS_SUCCESS);
}
#else
static void cache_shared_cpu_map_setup(unsigned int cpu,
struct cache_info * this_leaf)
{
cpu_set(cpu, this_leaf->shared_cpu_map);
return;
}
#endif

static ssize_t show_coherency_line_size(struct cache_info *this_leaf,
char *buf)
{
return sprintf(buf, "%u\n", 1 << this_leaf->cci.pcci_line_size);
}

static ssize_t show_ways_of_associativity(struct cache_info *this_leaf,
char *buf)
{
return sprintf(buf, "%u\n", this_leaf->cci.pcci_assoc);
}

static ssize_t show_attributes(struct cache_info *this_leaf, char *buf)
{
return sprintf(buf,
"%s\n",
cache_mattrib[this_leaf->cci.pcci_cache_attr]);
}

static ssize_t show_size(struct cache_info *this_leaf, char *buf)
{
return sprintf(buf, "%uK\n", this_leaf->cci.pcci_cache_size / 1024);
}

static ssize_t show_number_of_sets(struct cache_info *this_leaf, char *buf)
{
unsigned number_of_sets = this_leaf->cci.pcci_cache_size;
number_of_sets /= this_leaf->cci.pcci_assoc;
number_of_sets /= 1 << this_leaf->cci.pcci_line_size;

return sprintf(buf, "%u\n", number_of_sets);
}

static ssize_t show_shared_cpu_map(struct cache_info *this_leaf, char *buf)
{
ssize_t len;
cpumask_t shared_cpu_map;

cpus_and(shared_cpu_map, this_leaf->shared_cpu_map, cpu_online_map);
len = cpumask_scnprintf(buf, NR_CPUS+1, shared_cpu_map);
len += sprintf(buf+len, "\n");
return len;
}

static ssize_t show_type(struct cache_info *this_leaf, char *buf)
{
int type = this_leaf->type + this_leaf->cci.pcci_unified;
return sprintf(buf, "%s\n", cache_types[type]);
}

static ssize_t show_level(struct cache_info *this_leaf, char *buf)
{
return sprintf(buf, "%u\n", this_leaf->level);
}

struct cache_attr {
struct attribute attr;
ssize_t (*show)(struct cache_info *, char *);
ssize_t (*store)(struct cache_info *, const char *, size_t count);
};

#ifdef define_one_ro
#undef define_one_ro
#endif
#define define_one_ro(_name) \
static struct cache_attr _name = \
__ATTR(_name, 0444, show_##_name, NULL)

define_one_ro(level);
define_one_ro(type);
define_one_ro(coherency_line_size);
define_one_ro(ways_of_associativity);
define_one_ro(size);
define_one_ro(number_of_sets);
define_one_ro(shared_cpu_map);
define_one_ro(attributes);

static struct attribute * cache_default_attrs[] = {
&type.attr,
&level.attr,
&coherency_line_size.attr,
&ways_of_associativity.attr,
&attributes.attr,
&size.attr,
&number_of_sets.attr,
&shared_cpu_map.attr,
NULL
};

#define to_object(k) container_of(k, struct cache_info, kobj)
#define to_attr(a) container_of(a, struct cache_attr, attr)

static ssize_t cache_show(struct kobject * kobj, struct attribute * attr, char * buf)
{
struct cache_attr *fattr = to_attr(attr);
struct cache_info *this_leaf = to_object(kobj);
ssize_t ret;

ret = fattr->show ? fattr->show(this_leaf, buf) : 0;
return ret;
}

static struct sysfs_ops cache_sysfs_ops = {
.show = cache_show
};

static struct kobj_type cache_ktype = {
.sysfs_ops = &cache_sysfs_ops,
.default_attrs = cache_default_attrs,
};

static struct kobj_type cache_ktype_percpu_entry = {
.sysfs_ops = &cache_sysfs_ops,
};

static void __cpuinit cpu_cache_sysfs_exit(unsigned int cpu)
{
if (all_cpu_cache_info[cpu].cache_leaves) {
kfree(all_cpu_cache_info[cpu].cache_leaves);
all_cpu_cache_info[cpu].cache_leaves = NULL;
}
all_cpu_cache_info[cpu].num_cache_leaves = 0;
memset(&all_cpu_cache_info[cpu].kobj, 0, sizeof(struct kobject));

return;
}

static int __cpuinit cpu_cache_sysfs_init(unsigned int cpu)
{
u64 i, levels, unique_caches;
pal_cache_config_info_t cci;
int j;
s64 status;
struct cache_info *this_cache;
int num_cache_leaves = 0;

if ((status = ia64_pal_cache_summary(&levels, &unique_caches)) != 0) {
printk(KERN_ERR "ia64_pal_cache_summary=%ld\n", status);
return -1;
}

this_cache=kzalloc(sizeof(struct cache_info)*unique_caches,
GFP_KERNEL);
if (this_cache == NULL)
return -ENOMEM;

for (i=0; i < levels; i++) {
for (j=2; j >0 ; j--) {
if ((status=ia64_pal_cache_config_info(i,j, &cci)) !=
PAL_STATUS_SUCCESS)
continue;

this_cache[num_cache_leaves].cci = cci;
this_cache[num_cache_leaves].level = i + 1;
this_cache[num_cache_leaves].type = j;

cache_shared_cpu_map_setup(cpu,
&this_cache[num_cache_leaves]);
num_cache_leaves ++;
}
}

all_cpu_cache_info[cpu].cache_leaves = this_cache;
all_cpu_cache_info[cpu].num_cache_leaves = num_cache_leaves;

memset(&all_cpu_cache_info[cpu].kobj, 0, sizeof(struct kobject));

return 0;
}

/* Add cache interface for CPU device */
static int __cpuinit cache_add_dev(struct sys_device * sys_dev)
{
unsigned int cpu = sys_dev->id;
unsigned long i, j;
struct cache_info *this_object;
int retval = 0;
cpumask_t oldmask;

if (all_cpu_cache_info[cpu].kobj.parent)
return 0;

oldmask = current->cpus_allowed;
retval = set_cpus_allowed(current, cpumask_of_cpu(cpu));
if (unlikely(retval))
return retval;

retval = cpu_cache_sysfs_init(cpu);
set_cpus_allowed(current, oldmask);
if (unlikely(retval < 0))
return retval;

all_cpu_cache_info[cpu].kobj.parent = &sys_dev->kobj;
kobject_set_name(&all_cpu_cache_info[cpu].kobj, "%s", "cache");
all_cpu_cache_info[cpu].kobj.ktype = &cache_ktype_percpu_entry;
retval = kobject_register(&all_cpu_cache_info[cpu].kobj);

for (i = 0; i < all_cpu_cache_info[cpu].num_cache_leaves; i++) {
this_object = LEAF_KOBJECT_PTR(cpu,i);
this_object->kobj.parent = &all_cpu_cache_info[cpu].kobj;
kobject_set_name(&(this_object->kobj), "index%1lu", i);
this_object->kobj.ktype = &cache_ktype;
retval = kobject_register(&(this_object->kobj));
if (unlikely(retval)) {
for (j = 0; j < i; j++) {
kobject_unregister(
&(LEAF_KOBJECT_PTR(cpu,j)->kobj));
}
kobject_unregister(&all_cpu_cache_info[cpu].kobj);
cpu_cache_sysfs_exit(cpu);
break;
}
}
return retval;
}

/* Remove cache interface for CPU device */
static int __cpuinit cache_remove_dev(struct sys_device * sys_dev)
{
unsigned int cpu = sys_dev->id;
unsigned long i;

for (i = 0; i < all_cpu_cache_info[cpu].num_cache_leaves; i++)
kobject_unregister(&(LEAF_KOBJECT_PTR(cpu,i)->kobj));

if (all_cpu_cache_info[cpu].kobj.parent) {
kobject_unregister(&all_cpu_cache_info[cpu].kobj);
memset(&all_cpu_cache_info[cpu].kobj,
0,
sizeof(struct kobject));
}

cpu_cache_sysfs_exit(cpu);

return 0;
}

/*
* When a cpu is hot-plugged, do a check and initiate
* cache kobject if necessary
*/
static int __cpuinit cache_cpu_callback(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
struct sys_device *sys_dev;

sys_dev = get_cpu_sysdev(cpu);
switch (action) {
case CPU_ONLINE:
cache_add_dev(sys_dev);
break;
case CPU_DEAD:
cache_remove_dev(sys_dev);
break;
}
return NOTIFY_OK;
}

static struct notifier_block cache_cpu_notifier =
{
.notifier_call = cache_cpu_callback
};

static int __cpuinit cache_sysfs_init(void)
{
int i;

for_each_online_cpu(i) {
cache_cpu_callback(&cache_cpu_notifier, CPU_ONLINE,
(void *)(long)i);
}

register_cpu_notifier(&cache_cpu_notifier);

return 0;
}

device_initcall(cache_sysfs_init);

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