x86, amd: Support L3 Cache Partitioning on AMD family 0x15 CPUs
L3 Cache Partitioning allows selecting which of the 4 L3 subcaches can be used
for evictions by the L2 cache of each compute unit. By writing a 4-bit
hexadecimal mask into the the sysfs file
/sys/devices/system/cpu/cpuX/cache/index3/subcaches, the user can set the
enabled subcaches for a CPU.
The settings are directly read from and written to the hardware, so there is no
way to have contradicting settings for two CPUs belonging to the same compute
unit. Writing will always overwrite any previous setting for a compute unit.
Signed-off-by: Hans Rosenfeld <hans.rosenfeld@amd.com>
Cc: <Andreas.Herrmann3@amd.com>
LKML-Reference: <1297098639-431383-1-git-send-email-hans.rosenfeld@amd.com>
[ -v3: minor style fixes ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/cpu/intel_cacheinfo.c b/arch/x86/kernel/cpu/intel_cacheinfo.c
index ec2c19a..90cc675 100644
--- a/arch/x86/kernel/cpu/intel_cacheinfo.c
+++ b/arch/x86/kernel/cpu/intel_cacheinfo.c
@@ -304,8 +304,9 @@
struct _cache_attr {
struct attribute attr;
- ssize_t (*show)(struct _cpuid4_info *, char *);
- ssize_t (*store)(struct _cpuid4_info *, const char *, size_t count);
+ ssize_t (*show)(struct _cpuid4_info *, char *, unsigned int);
+ ssize_t (*store)(struct _cpuid4_info *, const char *, size_t count,
+ unsigned int);
};
#ifdef CONFIG_AMD_NB
@@ -400,7 +401,8 @@
#define SHOW_CACHE_DISABLE(slot) \
static ssize_t \
-show_cache_disable_##slot(struct _cpuid4_info *this_leaf, char *buf) \
+show_cache_disable_##slot(struct _cpuid4_info *this_leaf, char *buf, \
+ unsigned int cpu) \
{ \
return show_cache_disable(this_leaf, buf, slot); \
}
@@ -512,7 +514,8 @@
#define STORE_CACHE_DISABLE(slot) \
static ssize_t \
store_cache_disable_##slot(struct _cpuid4_info *this_leaf, \
- const char *buf, size_t count) \
+ const char *buf, size_t count, \
+ unsigned int cpu) \
{ \
return store_cache_disable(this_leaf, buf, count, slot); \
}
@@ -524,6 +527,39 @@
static struct _cache_attr cache_disable_1 = __ATTR(cache_disable_1, 0644,
show_cache_disable_1, store_cache_disable_1);
+static ssize_t
+show_subcaches(struct _cpuid4_info *this_leaf, char *buf, unsigned int cpu)
+{
+ if (!this_leaf->l3 || !amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
+ return -EINVAL;
+
+ return sprintf(buf, "%x\n", amd_get_subcaches(cpu));
+}
+
+static ssize_t
+store_subcaches(struct _cpuid4_info *this_leaf, const char *buf, size_t count,
+ unsigned int cpu)
+{
+ unsigned long val;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (!this_leaf->l3 || !amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
+ return -EINVAL;
+
+ if (strict_strtoul(buf, 16, &val) < 0)
+ return -EINVAL;
+
+ if (amd_set_subcaches(cpu, val))
+ return -EINVAL;
+
+ return count;
+}
+
+static struct _cache_attr subcaches =
+ __ATTR(subcaches, 0644, show_subcaches, store_subcaches);
+
#else /* CONFIG_AMD_NB */
#define amd_init_l3_cache(x, y)
#endif /* CONFIG_AMD_NB */
@@ -532,9 +568,9 @@
__cpuinit cpuid4_cache_lookup_regs(int index,
struct _cpuid4_info_regs *this_leaf)
{
- union _cpuid4_leaf_eax eax;
- union _cpuid4_leaf_ebx ebx;
- union _cpuid4_leaf_ecx ecx;
+ union _cpuid4_leaf_eax eax;
+ union _cpuid4_leaf_ebx ebx;
+ union _cpuid4_leaf_ecx ecx;
unsigned edx;
if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
@@ -870,8 +906,8 @@
#define INDEX_KOBJECT_PTR(x, y) (&((per_cpu(ici_index_kobject, x))[y]))
#define show_one_plus(file_name, object, val) \
-static ssize_t show_##file_name \
- (struct _cpuid4_info *this_leaf, char *buf) \
+static ssize_t show_##file_name(struct _cpuid4_info *this_leaf, char *buf, \
+ unsigned int cpu) \
{ \
return sprintf(buf, "%lu\n", (unsigned long)this_leaf->object + val); \
}
@@ -882,7 +918,8 @@
show_one_plus(ways_of_associativity, ebx.split.ways_of_associativity, 1);
show_one_plus(number_of_sets, ecx.split.number_of_sets, 1);
-static ssize_t show_size(struct _cpuid4_info *this_leaf, char *buf)
+static ssize_t show_size(struct _cpuid4_info *this_leaf, char *buf,
+ unsigned int cpu)
{
return sprintf(buf, "%luK\n", this_leaf->size / 1024);
}
@@ -906,17 +943,20 @@
return n;
}
-static inline ssize_t show_shared_cpu_map(struct _cpuid4_info *leaf, char *buf)
+static inline ssize_t show_shared_cpu_map(struct _cpuid4_info *leaf, char *buf,
+ unsigned int cpu)
{
return show_shared_cpu_map_func(leaf, 0, buf);
}
-static inline ssize_t show_shared_cpu_list(struct _cpuid4_info *leaf, char *buf)
+static inline ssize_t show_shared_cpu_list(struct _cpuid4_info *leaf, char *buf,
+ unsigned int cpu)
{
return show_shared_cpu_map_func(leaf, 1, buf);
}
-static ssize_t show_type(struct _cpuid4_info *this_leaf, char *buf)
+static ssize_t show_type(struct _cpuid4_info *this_leaf, char *buf,
+ unsigned int cpu)
{
switch (this_leaf->eax.split.type) {
case CACHE_TYPE_DATA:
@@ -974,6 +1014,9 @@
if (amd_nb_has_feature(AMD_NB_L3_INDEX_DISABLE))
n += 2;
+ if (amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
+ n += 1;
+
attrs = kzalloc(n * sizeof (struct attribute *), GFP_KERNEL);
if (attrs == NULL)
return attrs = default_attrs;
@@ -986,6 +1029,9 @@
attrs[n++] = &cache_disable_1.attr;
}
+ if (amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
+ attrs[n++] = &subcaches.attr;
+
return attrs;
}
#endif
@@ -998,7 +1044,7 @@
ret = fattr->show ?
fattr->show(CPUID4_INFO_IDX(this_leaf->cpu, this_leaf->index),
- buf) :
+ buf, this_leaf->cpu) :
0;
return ret;
}
@@ -1012,7 +1058,7 @@
ret = fattr->store ?
fattr->store(CPUID4_INFO_IDX(this_leaf->cpu, this_leaf->index),
- buf, count) :
+ buf, count, this_leaf->cpu) :
0;
return ret;
}