[PATCH 3/3] Cleanup L3 cache index disable support

From: Hans Rosenfeld
Date: Fri Oct 29 2010 - 11:15:52 EST


Adaptions to the changes of the AMD northbridge caching code: instead of
a bool in each l3 struct, use a flag in amd_northbridges.flags to
indicate L3 cache index disable support; use a pointer to the whole
northbridge instead of the misc device in the l3 struct; simplify the
initialisation; dynamically generate sysfs attribute array.

Signed-off-by: Hans Rosenfeld <hans.rosenfeld@xxxxxxx>
---
arch/x86/include/asm/amd_nb.h | 1 +
arch/x86/kernel/amd_nb.c | 10 ++
arch/x86/kernel/cpu/intel_cacheinfo.c | 147 ++++++++++++++-------------------
3 files changed, 74 insertions(+), 84 deletions(-)

diff --git a/arch/x86/include/asm/amd_nb.h b/arch/x86/include/asm/amd_nb.h
index 4d7ec7d..6aee50d 100644
--- a/arch/x86/include/asm/amd_nb.h
+++ b/arch/x86/include/asm/amd_nb.h
@@ -25,6 +25,7 @@ struct amd_northbridge_info {
extern struct amd_northbridge_info amd_northbridges;

#define AMD_NB_GART 0x1
+#define AMD_NB_L3_INDEX_DISABLE 0x2

#ifdef CONFIG_AMD_NB

diff --git a/arch/x86/kernel/amd_nb.c b/arch/x86/kernel/amd_nb.c
index 63c8b4f..affacb5 100644
--- a/arch/x86/kernel/amd_nb.c
+++ b/arch/x86/kernel/amd_nb.c
@@ -68,6 +68,16 @@ int amd_cache_northbridges(void)
boot_cpu_data.x86 == 0x15)
amd_northbridges.flags |= AMD_NB_GART;

+ /*
+ * Some CPU families support L3 Cache Index Disable. There are some
+ * limitations because of E382 and E388 on family 0x10.
+ */
+ if (boot_cpu_data.x86 == 0x10 &&
+ boot_cpu_data.x86_model >= 0x8 &&
+ (boot_cpu_data.x86_model > 0x9 ||
+ boot_cpu_data.x86_mask >= 0x1))
+ amd_northbridges.flags |= AMD_NB_L3_INDEX_DISABLE;
+
return 0;
}
EXPORT_SYMBOL_GPL(amd_cache_northbridges);
diff --git a/arch/x86/kernel/cpu/intel_cacheinfo.c b/arch/x86/kernel/cpu/intel_cacheinfo.c
index 6b8ea74..9ecf81f 100644
--- a/arch/x86/kernel/cpu/intel_cacheinfo.c
+++ b/arch/x86/kernel/cpu/intel_cacheinfo.c
@@ -149,8 +149,7 @@ union _cpuid4_leaf_ecx {
};

struct amd_l3_cache {
- struct pci_dev *dev;
- bool can_disable;
+ struct amd_northbridge *nb;
unsigned indices;
u8 subcaches[4];
};
@@ -311,14 +310,12 @@ struct _cache_attr {
/*
* L3 cache descriptors
*/
-static struct amd_l3_cache **__cpuinitdata l3_caches;
-
static void __cpuinit amd_calc_l3_indices(struct amd_l3_cache *l3)
{
unsigned int sc0, sc1, sc2, sc3;
u32 val = 0;

- pci_read_config_dword(l3->dev, 0x1C4, &val);
+ pci_read_config_dword(l3->nb->misc, 0x1C4, &val);

/* calculate subcache sizes */
l3->subcaches[0] = sc0 = !(val & BIT(0));
@@ -330,47 +327,14 @@ static void __cpuinit amd_calc_l3_indices(struct amd_l3_cache *l3)
l3->indices = (max(max3(sc0, sc1, sc2), sc3) << 10) - 1;
}

-static struct amd_l3_cache * __cpuinit amd_init_l3_cache(int node)
-{
- struct amd_l3_cache *l3;
- struct pci_dev *dev = node_to_amd_nb(node)->misc;
-
- l3 = kzalloc(sizeof(struct amd_l3_cache), GFP_ATOMIC);
- if (!l3) {
- printk(KERN_WARNING "Error allocating L3 struct\n");
- return NULL;
- }
-
- l3->dev = dev;
-
- amd_calc_l3_indices(l3);
-
- return l3;
-}
-
-static void __cpuinit amd_check_l3_disable(struct _cpuid4_info_regs *this_leaf,
- int index)
+static void __cpuinit amd_init_l3_cache(struct _cpuid4_info_regs *this_leaf,
+ int index)
{
+ static struct amd_l3_cache *__cpuinitdata l3_caches;
int node;

- if (boot_cpu_data.x86 != 0x10)
- return;
-
- if (index < 3)
- return;
-
- /* see errata #382 and #388 */
- if (boot_cpu_data.x86_model < 0x8)
- return;
-
- if ((boot_cpu_data.x86_model == 0x8 ||
- boot_cpu_data.x86_model == 0x9)
- &&
- boot_cpu_data.x86_mask < 0x1)
- return;
-
- /* not in virtualized environments */
- if (amd_nb_num() == 0)
+ /* only for L3, and not in virtualized environments */
+ if (index < 3 || amd_nb_num() == 0)
return;

/*
@@ -378,7 +342,7 @@ static void __cpuinit amd_check_l3_disable(struct _cpuid4_info_regs *this_leaf,
* never freed but this is done only on shutdown so it doesn't matter.
*/
if (!l3_caches) {
- int size = amd_nb_num() * sizeof(struct amd_l3_cache *);
+ int size = amd_nb_num() * sizeof(struct amd_l3_cache);

l3_caches = kzalloc(size, GFP_ATOMIC);
if (!l3_caches)
@@ -387,14 +351,12 @@ static void __cpuinit amd_check_l3_disable(struct _cpuid4_info_regs *this_leaf,

node = amd_get_nb_id(smp_processor_id());

- if (!l3_caches[node]) {
- l3_caches[node] = amd_init_l3_cache(node);
- l3_caches[node]->can_disable = true;
+ if (!l3_caches[node].nb) {
+ l3_caches[node].nb = node_to_amd_nb(node);
+ amd_calc_l3_indices(&l3_caches[node]);
}

- WARN_ON(!l3_caches[node]);
-
- this_leaf->l3 = l3_caches[node];
+ this_leaf->l3 = &l3_caches[node];
}

/*
@@ -408,7 +370,7 @@ int amd_get_l3_disable_slot(struct amd_l3_cache *l3, unsigned slot)
{
unsigned int reg = 0;

- pci_read_config_dword(l3->dev, 0x1BC + slot * 4, &reg);
+ pci_read_config_dword(l3->nb->misc, 0x1BC + slot * 4, &reg);

/* check whether this slot is activated already */
if (reg & (3UL << 30))
@@ -422,7 +384,8 @@ static ssize_t show_cache_disable(struct _cpuid4_info *this_leaf, char *buf,
{
int index;

- if (!this_leaf->l3 || !this_leaf->l3->can_disable)
+ if (!this_leaf->l3 ||
+ !amd_nb_has_feature(AMD_NB_L3_INDEX_DISABLE))
return -EINVAL;

index = amd_get_l3_disable_slot(this_leaf->l3, slot);
@@ -457,7 +420,7 @@ static void amd_l3_disable_index(struct amd_l3_cache *l3, int cpu,
if (!l3->subcaches[i])
continue;

- pci_write_config_dword(l3->dev, 0x1BC + slot * 4, reg);
+ pci_write_config_dword(l3->nb->misc, 0x1BC + slot * 4, reg);

/*
* We need to WBINVD on a core on the node containing the L3
@@ -467,7 +430,7 @@ static void amd_l3_disable_index(struct amd_l3_cache *l3, int cpu,
wbinvd_on_cpu(cpu);

reg |= BIT(31);
- pci_write_config_dword(l3->dev, 0x1BC + slot * 4, reg);
+ pci_write_config_dword(l3->nb->misc, 0x1BC + slot * 4, reg);
}
}

@@ -524,7 +487,8 @@ static ssize_t store_cache_disable(struct _cpuid4_info *this_leaf,
if (!capable(CAP_SYS_ADMIN))
return -EPERM;

- if (!this_leaf->l3 || !this_leaf->l3->can_disable)
+ if (!this_leaf->l3 ||
+ !amd_nb_has_feature(AMD_NB_L3_INDEX_DISABLE))
return -EINVAL;

cpu = cpumask_first(to_cpumask(this_leaf->shared_cpu_map));
@@ -545,7 +509,7 @@ static ssize_t store_cache_disable(struct _cpuid4_info *this_leaf,
#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) \
{ \
return store_cache_disable(this_leaf, buf, count, slot); \
}
@@ -558,10 +522,7 @@ static struct _cache_attr cache_disable_1 = __ATTR(cache_disable_1, 0644,
show_cache_disable_1, store_cache_disable_1);

#else /* CONFIG_AMD_NB */
-static void __cpuinit
-amd_check_l3_disable(struct _cpuid4_info_regs *this_leaf, int index)
-{
-};
+#define amd_init_l3_cache(x, y)
#endif /* CONFIG_AMD_NB */

static int
@@ -575,7 +536,7 @@ __cpuinit cpuid4_cache_lookup_regs(int index,

if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
amd_cpuid4(index, &eax, &ebx, &ecx);
- amd_check_l3_disable(this_leaf, index);
+ amd_init_l3_cache(this_leaf, index);
} else {
cpuid_count(4, index, &eax.full, &ebx.full, &ecx.full, &edx);
}
@@ -983,30 +944,48 @@ define_one_ro(size);
define_one_ro(shared_cpu_map);
define_one_ro(shared_cpu_list);

-#define DEFAULT_SYSFS_CACHE_ATTRS \
- &type.attr, \
- &level.attr, \
- &coherency_line_size.attr, \
- &physical_line_partition.attr, \
- &ways_of_associativity.attr, \
- &number_of_sets.attr, \
- &size.attr, \
- &shared_cpu_map.attr, \
- &shared_cpu_list.attr
-
static struct attribute *default_attrs[] = {
- DEFAULT_SYSFS_CACHE_ATTRS,
+ &type.attr,
+ &level.attr,
+ &coherency_line_size.attr,
+ &physical_line_partition.attr,
+ &ways_of_associativity.attr,
+ &number_of_sets.attr,
+ &size.attr,
+ &shared_cpu_map.attr,
+ &shared_cpu_list.attr,
NULL
};

-static struct attribute *default_l3_attrs[] = {
- DEFAULT_SYSFS_CACHE_ATTRS,
#ifdef CONFIG_AMD_NB
- &cache_disable_0.attr,
- &cache_disable_1.attr,
+static struct attribute ** __cpuinit amd_l3_attrs(void)
+{
+ static struct attribute **attrs;
+ int n;
+
+ if (attrs)
+ return attrs;
+
+ n = sizeof (default_attrs) / sizeof (struct attribute *);
+
+ if (amd_nb_has_feature(AMD_NB_L3_INDEX_DISABLE))
+ n += 2;
+
+ attrs = kzalloc(n * sizeof (struct attribute *), GFP_KERNEL);
+ if (attrs == NULL)
+ return attrs = default_attrs;
+
+ for (n = 0; default_attrs[n]; n++)
+ attrs[n] = default_attrs[n];
+
+ if (amd_nb_has_feature(AMD_NB_L3_INDEX_DISABLE)) {
+ attrs[n++] = &cache_disable_0.attr;
+ attrs[n++] = &cache_disable_1.attr;
+ }
+
+ return attrs;
+}
#endif
- NULL
-};

static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
{
@@ -1117,11 +1096,11 @@ static int __cpuinit cache_add_dev(struct sys_device * sys_dev)

this_leaf = CPUID4_INFO_IDX(cpu, i);

- if (this_leaf->l3 && this_leaf->l3->can_disable)
- ktype_cache.default_attrs = default_l3_attrs;
- else
- ktype_cache.default_attrs = default_attrs;
-
+ ktype_cache.default_attrs = default_attrs;
+#ifdef CONFIG_AMD_NB
+ if (this_leaf->l3)
+ ktype_cache.default_attrs = amd_l3_attrs();
+#endif
retval = kobject_init_and_add(&(this_object->kobj),
&ktype_cache,
per_cpu(ici_cache_kobject, cpu),
--
1.5.6.5


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