x86: Fix CPU llc_shared_map information for AMD Magny-Cours

Construct entire NodeID and use it as cpu_llc_id. Thus internal node
siblings are stored in llc_shared_map.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 63 insertions, 1 deletions

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 0a717fc6aeb6..a76d2c18f150 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -251,6 +251,64 @@ static int __cpuinit nearby_node(int apicid)
 #endif
 
 /*
+ * Fixup core topology information for AMD multi-node processors.
+ * Assumption 1: Number of cores in each internal node is the same.
+ * Assumption 2: Mixed systems with both single-node and dual-node
+ *               processors are not supported.
+ */
+#ifdef CONFIG_X86_HT
+static void __cpuinit amd_fixup_dcm(struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_PCI
+        u32 t, cpn;
+        u8 n, n_id;
+        int cpu = smp_processor_id();
+
+        /* fixup topology information only once for a core */
+        if (cpu_has(c, X86_FEATURE_AMD_DCM))
+                return;
+
+        /* check for multi-node processor on boot cpu */
+        t = read_pci_config(0, 24, 3, 0xe8);
+        if (!(t & (1 << 29)))
+                return;
+
+        set_cpu_cap(c, X86_FEATURE_AMD_DCM);
+
+        /* cores per node: each internal node has half the number of cores */
+        cpn = c->x86_max_cores >> 1;
+
+        /* even-numbered NB_id of this dual-node processor */
+        n = c->phys_proc_id << 1;
+
+        /*
+         * determine internal node id and assign cores fifty-fifty to
+         * each node of the dual-node processor
+         */
+        t = read_pci_config(0, 24 + n, 3, 0xe8);
+        n = (t>>30) & 0x3;
+        if (n == 0) {
+                if (c->cpu_core_id < cpn)
+                        n_id = 0;
+                else
+                        n_id = 1;
+        } else {
+                if (c->cpu_core_id < cpn)
+                        n_id = 1;
+                else
+                        n_id = 0;
+        }
+
+        /* compute entire NodeID, use llc_shared_map to store sibling info */
+        per_cpu(cpu_llc_id, cpu) = (c->phys_proc_id << 1) + n_id;
+
+        /* fixup core id to be in range from 0 to cpn */
+        c->cpu_core_id = c->cpu_core_id % cpn;
+#endif
+}
+#endif
+
+/*
  * On a AMD dual core setup the lower bits of the APIC id distingush the cores.
  * Assumes number of cores is a power of two.
  */
@@ -267,6 +325,9 @@ static void __cpuinit amd_detect_cmp(struct cpuinfo_x86 *c)
         c->phys_proc_id = c->initial_apicid >> bits;
         /* use socket ID also for last level cache */
         per_cpu(cpu_llc_id, cpu) = c->phys_proc_id;
+        /* fixup topology information on multi-node processors */
+        if ((c->x86 == 0x10) && (c->x86_model == 9))
+                amd_fixup_dcm(c);
 #endif
 }
 
@@ -277,7 +338,8 @@ static void __cpuinit srat_detect_node(struct cpuinfo_x86 *c)
         int node;
         unsigned apicid = cpu_has_apic ? hard_smp_processor_id() : c->apicid;
 
-        node = c->phys_proc_id;
+        node = per_cpu(cpu_llc_id, cpu);
+
         if (apicid_to_node[apicid] != NUMA_NO_NODE)
                 node = apicid_to_node[apicid];
         if (!node_online(node)) {