x86, cacheinfo: Make L3 cache info per node
Borislav Petkov [Thu, 22 Apr 2010 14:07:01 +0000 (16:07 +0200)]
Currently, we're allocating L3 cache info and calculating indices for
each online cpu which is clearly superfluous. Instead, we need to do
this per-node as is each L3 cache.

No functional change, only per-cpu memory savings.

-v2: Allocate L3 cache descriptors array dynamically.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <1271945222-5283-5-git-send-email-bp@amd64.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/kernel/cpu/intel_cacheinfo.c

index ff663ca..1346e9c 100644 (file)
@@ -307,19 +307,18 @@ struct _cache_attr {
 };
 
 #ifdef CONFIG_CPU_SUP_AMD
+
+/*
+ * L3 cache descriptors
+ */
+static struct amd_l3_cache **__cpuinitdata l3_caches;
+
 static void __cpuinit amd_calc_l3_indices(struct amd_l3_cache *l3)
 {
-       /*
-        * We're called over smp_call_function_single() and therefore
-        * are on the correct cpu.
-        */
-       int cpu = smp_processor_id();
-       int node = cpu_to_node(cpu);
-       struct pci_dev *dev = node_to_k8_nb_misc(node);
        unsigned int sc0, sc1, sc2, sc3;
        u32 val = 0;
 
-       pci_read_config_dword(dev, 0x1C4, &val);
+       pci_read_config_dword(l3->dev, 0x1C4, &val);
 
        /* calculate subcache sizes */
        l3->subcaches[0] = sc0 = !(val & BIT(0));
@@ -328,13 +327,31 @@ static void __cpuinit amd_calc_l3_indices(struct amd_l3_cache *l3)
        l3->subcaches[3] = sc3 = !(val & BIT(12)) + !(val & BIT(13));
 
        l3->indices = (max(max(max(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_k8_nb_misc(node);
+
+       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(int index, struct _cpuid4_info_regs *this_leaf)
 {
+       int node;
+
        if (boot_cpu_data.x86 != 0x10)
                return;
 
@@ -355,14 +372,28 @@ amd_check_l3_disable(int index, struct _cpuid4_info_regs *this_leaf)
        if (num_k8_northbridges == 0)
                return;
 
-       this_leaf->l3 = kzalloc(sizeof(struct amd_l3_cache), GFP_ATOMIC);
-       if (!this_leaf->l3) {
-               printk(KERN_WARNING "Error allocating L3 struct\n");
-               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 = num_k8_northbridges * sizeof(struct amd_l3_cache *);
+
+               l3_caches = kzalloc(size, GFP_ATOMIC);
+               if (!l3_caches)
+                       return;
        }
 
-       this_leaf->l3->can_disable = true;
-       amd_calc_l3_indices(this_leaf->l3);
+       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;
+       }
+
+       WARN_ON(!l3_caches[node]);
+
+       this_leaf->l3 = l3_caches[node];
 }
 
 static ssize_t show_cache_disable(struct _cpuid4_info *this_leaf, char *buf,