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

From: Borislav Petkov
Date: Tue Nov 16 2010 - 12:33:28 EST

Ping.

Ingo, hpa, any progress on those? Do we need to resend them against
tip/master or do you have objections?

Thanks.

On Fri, Oct 29, 2010 at 05:14:32PM +0200, Hans Rosenfeld wrote:
> 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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--
Regards/Gruss,
Boris.

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