[PATCH 01/01] x86: L3 cache index disable for 2.6.26

* Mark Langsdorf <[email protected]> wrote:

> New versions of AMD processors have support to disable parts of their
> L3 caches if too many MCEs are generated by the L3 cache.
>
> This patch provides a /sysfs interface under the cache hierarchy to
> display which caches indices are disabled (if any) and to monitoring
> applications to disable a cache index.
>
> This patch does not set an automatic policy to disable the L3 cache.
> Policy decisions would need to be made by a RAS handler. This patch
> merely makes it easier to see what indices are currently disabled.
>
> Signed-off-by: Mark Langsdorf <[email protected]>

applied to tip/x86/cpu, thanks Mark.

I've done some coding style fixes for the new functions you've
introduced, see that commit below.

Ingo

------------------->
commit 6cec0203a915739140c0a7fdf3498aa417123501
Author: Ingo Molnar <[email protected]>
Date: Mon Jul 21 13:34:21 2008 +0200

x86: L3 cache index disable for 2.6.26, cleanups

No change in functionality.

Signed-off-by: Ingo Molnar <[email protected]>
---
arch/x86/kernel/cpu/intel_cacheinfo.c | 115 +++++++++++++++++---------------
1 files changed, 61 insertions(+), 54 deletions(-)

diff --git a/arch/x86/kernel/cpu/intel_cacheinfo.c b/arch/x86/kernel/cpu/intel_cacheinfo.c
index 503c847..491892c 100644
--- a/arch/x86/kernel/cpu/intel_cacheinfo.c
+++ b/arch/x86/kernel/cpu/intel_cacheinfo.c
@@ -253,14 +253,16 @@ static void __cpuinit amd_cpuid4(int leaf, union _cpuid4_leaf_eax *eax,
(ebx->split.ways_of_associativity + 1) - 1;
}

-static void __cpuinit amd_check_l3_disable(int index, struct _cpuid4_info *this_leaf)
+static void __cpuinit
+amd_check_l3_disable(int index, struct _cpuid4_info *this_leaf)
{
if (index < 3)
return;
this_leaf->can_disable = 1;
}

-static int __cpuinit cpuid4_cache_lookup(int index, struct _cpuid4_info *this_leaf)
+static int
+__cpuinit cpuid4_cache_lookup(int index, struct _cpuid4_info *this_leaf)
{
union _cpuid4_leaf_eax eax;
union _cpuid4_leaf_ebx ebx;
@@ -271,19 +273,20 @@ static int __cpuinit cpuid4_cache_lookup(int index, struct _cpuid4_info *this_le
amd_cpuid4(index, &eax, &ebx, &ecx);
if (boot_cpu_data.x86 >= 0x10)
amd_check_l3_disable(index, this_leaf);
-
- } else
- cpuid_count(4, index, &eax.full, &ebx.full, &ecx.full, &edx);
+ } else {
+ cpuid_count(4, index, &eax.full, &ebx.full, &ecx.full, &edx);
+ }
+
if (eax.split.type == CACHE_TYPE_NULL)
return -EIO; /* better error ? */

this_leaf->eax = eax;
this_leaf->ebx = ebx;
this_leaf->ecx = ecx;
- this_leaf->size = (ecx.split.number_of_sets + 1) *
- (ebx.split.coherency_line_size + 1) *
- (ebx.split.physical_line_partition + 1) *
- (ebx.split.ways_of_associativity + 1);
+ this_leaf->size = (ecx.split.number_of_sets + 1) *
+ (ebx.split.coherency_line_size + 1) *
+ (ebx.split.physical_line_partition + 1) *
+ (ebx.split.ways_of_associativity + 1);
return 0;
}

@@ -649,59 +652,63 @@ static ssize_t show_type(struct _cpuid4_info *this_leaf, char *buf) {
}
}

-#define to_object(k) container_of(k, struct _index_kobject, kobj)
-#define to_attr(a) container_of(a, struct _cache_attr, attr)
+#define to_object(k) container_of(k, struct _index_kobject, kobj)
+#define to_attr(a) container_of(a, struct _cache_attr, attr)

static ssize_t show_cache_disable(struct _cpuid4_info *this_leaf, char *buf)
{
- struct pci_dev *dev;
- if (this_leaf->can_disable) {
- int i;
- ssize_t ret = 0;
- int node = cpu_to_node(first_cpu(this_leaf->shared_cpu_map));
- dev = k8_northbridges[node];
-
- for (i = 0; i < 2; i++) {
- unsigned int reg;
- pci_read_config_dword(dev, 0x1BC + i * 4, &reg);
- ret += sprintf(buf, "%sEntry: %d\n", buf, i);
- ret += sprintf(buf, "%sReads: %s\tNew Entries: %s\n",
- buf,
- reg & 0x80000000 ? "Disabled" : "Allowed",
- reg & 0x40000000 ? "Disabled" : "Allowed");
- ret += sprintf(buf, "%sSubCache: %x\tIndex: %x\n", buf,
- (reg & 0x30000) >> 16, reg & 0xfff);
+ int node = cpu_to_node(first_cpu(this_leaf->shared_cpu_map));
+ struct pci_dev *dev = k8_northbridges[node];
+ ssize_t ret = 0;
+ int i;

- }
- return ret;
+ if (!this_leaf->can_disable)
+ return sprintf(buf, "Feature not enabled\n");
+
+ for (i = 0; i < 2; i++) {
+ unsigned int reg;
+
+ pci_read_config_dword(dev, 0x1BC + i * 4, &reg);
+
+ ret += sprintf(buf, "%sEntry: %d\n", buf, i);
+ ret += sprintf(buf, "%sReads: %s\tNew Entries: %s\n",
+ buf,
+ reg & 0x80000000 ? "Disabled" : "Allowed",
+ reg & 0x40000000 ? "Disabled" : "Allowed");
+ ret += sprintf(buf, "%sSubCache: %x\tIndex: %x\n",
+ buf, (reg & 0x30000) >> 16, reg & 0xfff);
}
- return sprintf(buf, "Feature not enabled\n");
+ return ret;
}

-static ssize_t store_cache_disable(struct _cpuid4_info *this_leaf, const char *buf, size_t count)
+static ssize_t
+store_cache_disable(struct _cpuid4_info *this_leaf, const char *buf,
+ size_t count)
{
- struct pci_dev *dev;
- if (this_leaf->can_disable) {
- /* write the MSR value */
- unsigned int ret;
- unsigned int index, val;
- int node = cpu_to_node(first_cpu(this_leaf->shared_cpu_map));
- dev = k8_northbridges[node];
-
- if (strlen(buf) > 15)
- return -EINVAL;
- ret = sscanf(buf, "%x %x", &index, &val);
- if (ret != 2)
- return -EINVAL;
- if (index > 1)
- return -EINVAL;
- val |= 0xc0000000;
- pci_write_config_dword(dev, 0x1BC + index * 4, val & ~0x40000000);
- wbinvd();
- pci_write_config_dword(dev, 0x1BC + index * 4, val);
- return 1;
- }
- return 0;
+ int node = cpu_to_node(first_cpu(this_leaf->shared_cpu_map));
+ struct pci_dev *dev = k8_northbridges[node];
+ unsigned int ret, index, val;
+
+ if (!this_leaf->can_disable)
+ return 0;
+
+ /* write the MSR value */
+
+ if (strlen(buf) > 15)
+ return -EINVAL;
+
+ ret = sscanf(buf, "%x %x", &index, &val);
+ if (ret != 2)
+ return -EINVAL;
+ if (index > 1)
+ return -EINVAL;
+
+ val |= 0xc0000000;
+ pci_write_config_dword(dev, 0x1BC + index * 4, val & ~0x40000000);
+ wbinvd();
+ pci_write_config_dword(dev, 0x1BC + index * 4, val);
+
+ return 1;
}

struct _cache_attr {
--
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