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x86: cache_info: Kill the atomic allocation in amd_init_l3_cache()
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It's not a good reason to allocate memory in the smp function call
just because someone thought it's the most conveniant place.

The AMD L3 data is coupled to the northbridge info by a pointer to the
corresponding north bridge data. So allocating it with the northbridge
data and referencing the northbridge in the cache_info code instead
uses less memory and gets rid of that atomic allocation hack in the
smp function call.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Hans Rosenfeld <hans.rosenfeld@amd.com>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Mike Travis <travis@sgi.com>
Link: http://lkml.kernel.org/r/20110723212626.688229918@linutronix.de
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Thomas Gleixner authored and Ingo Molnar committed Sep 12, 2011
1 parent b7d11a7 commit d294604
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Showing 2 changed files with 32 additions and 48 deletions.
6 changes: 6 additions & 0 deletions arch/x86/include/asm/amd_nb.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,9 +19,15 @@ extern int amd_numa_init(void);
extern int amd_get_subcaches(int);
extern int amd_set_subcaches(int, int);

struct amd_l3_cache {
unsigned indices;
u8 subcaches[4];
};

struct amd_northbridge {
struct pci_dev *misc;
struct pci_dev *link;
struct amd_l3_cache l3_cache;
};

struct amd_northbridge_info {
Expand Down
74 changes: 26 additions & 48 deletions arch/x86/kernel/cpu/intel_cacheinfo.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -151,18 +151,12 @@ union _cpuid4_leaf_ecx {
u32 full;
};

struct amd_l3_cache {
struct amd_northbridge *nb;
unsigned indices;
u8 subcaches[4];
};

struct _cpuid4_info_regs {
union _cpuid4_leaf_eax eax;
union _cpuid4_leaf_ebx ebx;
union _cpuid4_leaf_ecx ecx;
unsigned long size;
struct amd_l3_cache *l3;
struct amd_northbridge *nb;
};

struct _cpuid4_info {
Expand Down Expand Up @@ -309,12 +303,13 @@ struct _cache_attr {
/*
* L3 cache descriptors
*/
static void __cpuinit amd_calc_l3_indices(struct amd_l3_cache *l3)
static void __cpuinit amd_calc_l3_indices(struct amd_northbridge *nb)
{
struct amd_l3_cache *l3 = &nb->l3_cache;
unsigned int sc0, sc1, sc2, sc3;
u32 val = 0;

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

/* calculate subcache sizes */
l3->subcaches[0] = sc0 = !(val & BIT(0));
Expand All @@ -328,33 +323,16 @@ static void __cpuinit amd_calc_l3_indices(struct amd_l3_cache *l3)
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;

/* only for L3, and not in virtualized environments */
if (index < 3 || amd_nb_num() == 0)
if (index < 3)
return;

/*
* Strictly speaking, the amount in @size below is leaked since it is
* 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);

l3_caches = kzalloc(size, GFP_ATOMIC);
if (!l3_caches)
return;
}

node = amd_get_nb_id(smp_processor_id());

if (!l3_caches[node].nb) {
l3_caches[node].nb = node_to_amd_nb(node);
amd_calc_l3_indices(&l3_caches[node]);
}

this_leaf->l3 = &l3_caches[node];
this_leaf->nb = node_to_amd_nb(node);
if (this_leaf->nb && !this_leaf->nb->l3_cache.indices)
amd_calc_l3_indices(this_leaf->nb);
}

/*
Expand All @@ -364,11 +342,11 @@ static void __cpuinit amd_init_l3_cache(struct _cpuid4_info_regs *this_leaf,
*
* @returns: the disabled index if used or negative value if slot free.
*/
int amd_get_l3_disable_slot(struct amd_l3_cache *l3, unsigned slot)
int amd_get_l3_disable_slot(struct amd_northbridge *nb, unsigned slot)
{
unsigned int reg = 0;

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

/* check whether this slot is activated already */
if (reg & (3UL << 30))
Expand All @@ -382,10 +360,10 @@ static ssize_t show_cache_disable(struct _cpuid4_info *this_leaf, char *buf,
{
int index;

if (!this_leaf->base.l3 || !amd_nb_has_feature(AMD_NB_L3_INDEX_DISABLE))
if (!this_leaf->base.nb || !amd_nb_has_feature(AMD_NB_L3_INDEX_DISABLE))
return -EINVAL;

index = amd_get_l3_disable_slot(this_leaf->base.l3, slot);
index = amd_get_l3_disable_slot(this_leaf->base.nb, slot);
if (index >= 0)
return sprintf(buf, "%d\n", index);

Expand All @@ -402,7 +380,7 @@ show_cache_disable_##slot(struct _cpuid4_info *this_leaf, char *buf, \
SHOW_CACHE_DISABLE(0)
SHOW_CACHE_DISABLE(1)

static void amd_l3_disable_index(struct amd_l3_cache *l3, int cpu,
static void amd_l3_disable_index(struct amd_northbridge *nb, int cpu,
unsigned slot, unsigned long idx)
{
int i;
Expand All @@ -415,10 +393,10 @@ static void amd_l3_disable_index(struct amd_l3_cache *l3, int cpu,
for (i = 0; i < 4; i++) {
u32 reg = idx | (i << 20);

if (!l3->subcaches[i])
if (!nb->l3_cache.subcaches[i])
continue;

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

/*
* We need to WBINVD on a core on the node containing the L3
Expand All @@ -428,7 +406,7 @@ 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->nb->misc, 0x1BC + slot * 4, reg);
pci_write_config_dword(nb->misc, 0x1BC + slot * 4, reg);
}
}

Expand All @@ -442,24 +420,24 @@ static void amd_l3_disable_index(struct amd_l3_cache *l3, int cpu,
*
* @return: 0 on success, error status on failure
*/
int amd_set_l3_disable_slot(struct amd_l3_cache *l3, int cpu, unsigned slot,
int amd_set_l3_disable_slot(struct amd_northbridge *nb, int cpu, unsigned slot,
unsigned long index)
{
int ret = 0;

/* check if @slot is already used or the index is already disabled */
ret = amd_get_l3_disable_slot(l3, slot);
ret = amd_get_l3_disable_slot(nb, slot);
if (ret >= 0)
return -EINVAL;

if (index > l3->indices)
if (index > nb->l3_cache.indices)
return -EINVAL;

/* check whether the other slot has disabled the same index already */
if (index == amd_get_l3_disable_slot(l3, !slot))
if (index == amd_get_l3_disable_slot(nb, !slot))
return -EINVAL;

amd_l3_disable_index(l3, cpu, slot, index);
amd_l3_disable_index(nb, cpu, slot, index);

return 0;
}
Expand All @@ -474,15 +452,15 @@ static ssize_t store_cache_disable(struct _cpuid4_info *this_leaf,
if (!capable(CAP_SYS_ADMIN))
return -EPERM;

if (!this_leaf->base.l3 || !amd_nb_has_feature(AMD_NB_L3_INDEX_DISABLE))
if (!this_leaf->base.nb || !amd_nb_has_feature(AMD_NB_L3_INDEX_DISABLE))
return -EINVAL;

cpu = cpumask_first(to_cpumask(this_leaf->shared_cpu_map));

if (strict_strtoul(buf, 10, &val) < 0)
return -EINVAL;

err = amd_set_l3_disable_slot(this_leaf->base.l3, cpu, slot, val);
err = amd_set_l3_disable_slot(this_leaf->base.nb, cpu, slot, val);
if (err) {
if (err == -EEXIST)
printk(KERN_WARNING "L3 disable slot %d in use!\n",
Expand Down Expand Up @@ -511,7 +489,7 @@ static struct _cache_attr cache_disable_1 = __ATTR(cache_disable_1, 0644,
static ssize_t
show_subcaches(struct _cpuid4_info *this_leaf, char *buf, unsigned int cpu)
{
if (!this_leaf->base.l3 || !amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
if (!this_leaf->base.nb || !amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
return -EINVAL;

return sprintf(buf, "%x\n", amd_get_subcaches(cpu));
Expand All @@ -526,7 +504,7 @@ store_subcaches(struct _cpuid4_info *this_leaf, const char *buf, size_t count,
if (!capable(CAP_SYS_ADMIN))
return -EPERM;

if (!this_leaf->base.l3 || !amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
if (!this_leaf->base.nb || !amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
return -EINVAL;

if (strict_strtoul(buf, 16, &val) < 0)
Expand Down Expand Up @@ -1118,7 +1096,7 @@ static int __cpuinit cache_add_dev(struct sys_device * sys_dev)

ktype_cache.default_attrs = default_attrs;
#ifdef CONFIG_AMD_NB
if (this_leaf->base.l3)
if (this_leaf->base.nb)
ktype_cache.default_attrs = amd_l3_attrs();
#endif
retval = kobject_init_and_add(&(this_object->kobj),
Expand Down

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