[PATCH] x86_64: Final support for AMD dual core

Clean up the code greatly.  Now uses the infrastructure from the Intel dual
core patch Should fix a final bug noticed by Tyan of not detecting the nodes
correctly in some corner cases.

Patch for x86-64 and i386

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 38 insertions, 33 deletions

diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
index ef74564eedeb..666fe8bcca0e 100644
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -715,14 +715,46 @@ static void __init display_cacheinfo(struct cpuinfo_x86 *c)
         }
 }
 
+#ifdef CONFIG_SMP
+/*
+ * 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.
+ */
+static void __init amd_detect_cmp(struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_SMP
+        int cpu = c->x86_apicid;
+        int node = 0;
+        if (c->x86_num_cores == 1)
+                return;
+        cpu_core_id[cpu] = cpu >> hweight32(c->x86_num_cores - 1);
+
+#ifdef CONFIG_NUMA
+        /* When an ACPI SRAT table is available use the mappings from SRAT
+           instead. */
+        if (acpi_numa <= 0) {
+                node = cpu_core_id[cpu];
+                if (!node_online(node))
+                        node = first_node(node_online_map);
+                cpu_to_node[cpu] = node;
+        } else {
+                node = cpu_to_node[cpu];
+        }
+#endif
+        printk(KERN_INFO "CPU %d(%d) -> Node %d -> Core %d\n",
+                        cpu, c->x86_num_cores, node, cpu_core_id[cpu]);
+#endif
+}
+#else
+static void __init amd_detect_cmp(struct cpuinfo_x86 *c)
+{
+}
+#endif
 
 static int __init init_amd(struct cpuinfo_x86 *c)
 {
         int r;
         int level;
-#ifdef CONFIG_NUMA
-        int cpu;
-#endif
 
         /* Bit 31 in normal CPUID used for nonstandard 3DNow ID;
            3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway */
@@ -750,21 +782,7 @@ static int __init init_amd(struct cpuinfo_x86 *c)
                 if (c->x86_num_cores & (c->x86_num_cores - 1))
                         c->x86_num_cores = 1;
 
-#ifdef CONFIG_NUMA
-                /* On a dual core setup the lower bits of apic id
-                   distingush the cores. Fix up the CPU<->node mappings
-                   here based on that.
-                   Assumes number of cores is a power of two.
-                   When using SRAT use mapping from SRAT. */
-                cpu = c->x86_apicid;
-                if (acpi_numa <= 0 && c->x86_num_cores > 1) {
-                        cpu_to_node[cpu] = cpu >> hweight32(c->x86_num_cores - 1);
-                        if (!node_online(cpu_to_node[cpu]))
-                                cpu_to_node[cpu] = first_node(node_online_map);
-                }
-                printk(KERN_INFO "CPU %d(%d) -> Node %d\n",
-                                cpu, c->x86_num_cores, cpu_to_node[cpu]);
-#endif
+                amd_detect_cmp(c);
         }
 
         return r;
@@ -777,7 +795,7 @@ static void __init detect_ht(struct cpuinfo_x86 *c)
         int     index_msb, tmp;
         int     cpu = smp_processor_id();
         
-        if (!cpu_has(c, X86_FEATURE_HT))
+        if (!cpu_has(c, X86_FEATURE_HT) || cpu_has(c, X86_FEATURE_CMP_LEGACY))
                 return;
 
         cpuid(1, &eax, &ebx, &ecx, &edx);
@@ -819,6 +837,7 @@ static void __init detect_ht(struct cpuinfo_x86 *c)
                 if (smp_num_siblings & (smp_num_siblings - 1))
                         index_msb++;
 
+                /* RED-PEN surely this must run in the non HT case too! -AK */
                 cpu_core_id[cpu] = phys_pkg_id(index_msb);
 
                 if (c->x86_num_cores > 1)
@@ -828,19 +847,6 @@ static void __init detect_ht(struct cpuinfo_x86 *c)
 #endif
 }
 
-static void __init sched_cmp_hack(struct cpuinfo_x86 *c)
-{
-#ifdef CONFIG_SMP
-        /* AMD dual core looks like HT but isn't really. Hide it from the
-           scheduler. This works around problems with the domain scheduler.
-           Also probably gives slightly better scheduling and disables
-           SMT nice which is harmful on dual core.
-           TBD tune the domain scheduler for dual core. */
-        if (c->x86_vendor == X86_VENDOR_AMD && cpu_has(c, X86_FEATURE_CMP_LEGACY))
-                smp_num_siblings = 1;
-#endif
-}
-
 /*
  * find out the number of processor cores on the die
  */
@@ -1009,7 +1015,6 @@ void __init identify_cpu(struct cpuinfo_x86 *c)
 
         select_idle_routine(c);
         detect_ht(c); 
-        sched_cmp_hack(c);
 
         /*
          * On SMP, boot_cpu_data holds the common feature set between