1 files changed, 65 insertions, 13 deletions

diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 2de00f870edc..6adb5a1e98bb 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -33,6 +33,7 @@
 #include <linux/serial.h>
 #include <linux/serial_8250.h>
 #include <linux/debugfs.h>
+#include <linux/percpu.h>
 #include <asm/io.h>
 #include <asm/prom.h>
 #include <asm/processor.h>
@@ -57,6 +58,7 @@
 #include <asm/mmu.h>
 #include <asm/lmb.h>
 #include <asm/xmon.h>
+#include <asm/cputhreads.h>
 
 #include "setup.h"
 
@@ -327,6 +329,31 @@ void __init check_for_initrd(void)
 
 #ifdef CONFIG_SMP
 
+int threads_per_core, threads_shift;
+cpumask_t threads_core_mask;
+
+static void __init cpu_init_thread_core_maps(int tpc)
+{
+        int i;
+
+        threads_per_core = tpc;
+        threads_core_mask = CPU_MASK_NONE;
+
+        /* This implementation only supports power of 2 number of threads
+         * for simplicity and performance
+         */
+        threads_shift = ilog2(tpc);
+        BUG_ON(tpc != (1 << threads_shift));
+
+        for (i = 0; i < tpc; i++)
+                cpu_set(i, threads_core_mask);
+
+        printk(KERN_INFO "CPU maps initialized for %d thread%s per core\n",
+               tpc, tpc > 1 ? "s" : "");
+        printk(KERN_DEBUG " (thread shift is %d)\n", threads_shift);
+}
+
+
 /**
  * setup_cpu_maps - initialize the following cpu maps:
  *                  cpu_possible_map
@@ -350,22 +377,32 @@ void __init smp_setup_cpu_maps(void)
 {
         struct device_node *dn = NULL;
         int cpu = 0;
+        int nthreads = 1;
+
+        DBG("smp_setup_cpu_maps()\n");
 
         while ((dn = of_find_node_by_type(dn, "cpu")) && cpu < NR_CPUS) {
                 const int *intserv;
-                int j, len = sizeof(u32), nthreads = 1;
+                int j, len;
+
+                DBG("  * %s...\n", dn->full_name);
 
                 intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s",
                                 &len);
-                if (intserv)
+                if (intserv) {
                         nthreads = len / sizeof(int);
-                else {
+                        DBG("    ibm,ppc-interrupt-server#s -> %d threads\n",
+                            nthreads);
+                } else {
+                        DBG("    no ibm,ppc-interrupt-server#s -> 1 thread\n");
                         intserv = of_get_property(dn, "reg", NULL);
                         if (!intserv)
                                 intserv = &cpu; /* assume logical == phys */
                 }
 
                 for (j = 0; j < nthreads && cpu < NR_CPUS; j++) {
+                        DBG("    thread %d -> cpu %d (hard id %d)\n",
+                            j, cpu, intserv[j]);
                         cpu_set(cpu, cpu_present_map);
                         set_hard_smp_processor_id(cpu, intserv[j]);
                         cpu_set(cpu, cpu_possible_map);
@@ -373,6 +410,12 @@ void __init smp_setup_cpu_maps(void)
                 }
         }
 
+        /* If no SMT supported, nthreads is forced to 1 */
+        if (!cpu_has_feature(CPU_FTR_SMT)) {
+                DBG("  SMT disabled ! nthreads forced to 1\n");
+                nthreads = 1;
+        }
+
 #ifdef CONFIG_PPC64
         /*
          * On pSeries LPAR, we need to know how many cpus
@@ -395,7 +438,7 @@ void __init smp_setup_cpu_maps(void)
 
                 /* Double maxcpus for processors which have SMT capability */
                 if (cpu_has_feature(CPU_FTR_SMT))
-                        maxcpus *= 2;
+                        maxcpus *= nthreads;
 
                 if (maxcpus > NR_CPUS) {
                         printk(KERN_WARNING
@@ -412,9 +455,16 @@ void __init smp_setup_cpu_maps(void)
         out:
                 of_node_put(dn);
         }
-
         vdso_data->processorCount = num_present_cpus();
 #endif /* CONFIG_PPC64 */
+
+        /* Initialize CPU <=> thread mapping/
+         *
+         * WARNING: We assume that the number of threads is the same for
+         * every CPU in the system. If that is not the case, then some code
+         * here will have to be reworked
+         */
+        cpu_init_thread_core_maps(nthreads);
 }
 
 /*
@@ -424,17 +474,19 @@ void __init smp_setup_cpu_maps(void)
  */
 void __init smp_setup_cpu_sibling_map(void)
 {
-#if defined(CONFIG_PPC64)
-        int cpu;
+#ifdef CONFIG_PPC64
+        int i, cpu, base;
 
-        /*
-         * Do the sibling map; assume only two threads per processor.
-         */
         for_each_possible_cpu(cpu) {
-                cpu_set(cpu, per_cpu(cpu_sibling_map, cpu));
-                if (cpu_has_feature(CPU_FTR_SMT))
-                        cpu_set(cpu ^ 0x1, per_cpu(cpu_sibling_map, cpu));
+                DBG("Sibling map for CPU %d:", cpu);
+                base = cpu_first_thread_in_core(cpu);
+                for (i = 0; i < threads_per_core; i++) {
+                        cpu_set(base + i, per_cpu(cpu_sibling_map, cpu));
+                        DBG(" %d", base + i);
+                }
+                DBG("\n");
         }
+
 #endif /* CONFIG_PPC64 */
 }
 #endif /* CONFIG_SMP */