[IA64] Export cpu cache info by sysfs

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>

1 files changed, 367 insertions, 0 deletions

diff --git a/arch/ia64/kernel/topology.c b/arch/ia64/kernel/topology.c
index 3b6fd798c4d6..b47476d655f1 100644
--- a/arch/ia64/kernel/topology.c
+++ b/arch/ia64/kernel/topology.c
@@ -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>
@@ -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>
@@ -101,3 +104,367 @@ out:
 }
 
 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);
+