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authorVaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>2010-10-06 08:36:59 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2010-11-29 15:48:19 +1100
commit99d86705253dcf728dbbec4d694a6764b6edb70c (patch)
treee4c68adab6448463a77141c1797671417f58242c /arch/powerpc/kernel/smp.c
parent787d44caa5bca249d8781d21b626c417f1e3cfc4 (diff)
downloadop-kernel-dev-99d86705253dcf728dbbec4d694a6764b6edb70c.zip
op-kernel-dev-99d86705253dcf728dbbec4d694a6764b6edb70c.tar.gz
powerpc: Cleanup APIs for cpu/thread/core mappings
These APIs take logical cpu number as input Change cpu_first_thread_in_core() to cpu_first_thread_sibling() Change cpu_last_thread_in_core() to cpu_last_thread_sibling() These APIs convert core number (index) to logical cpu/thread numbers Add cpu_first_thread_of_core(int core) Changed cpu_thread_to_core() to cpu_core_index_of_thread(int cpu) The goal is to make 'threads_per_core' accessible to the pseries_energy module. Instead of making an API to read threads_per_core, this is a higher level wrapper function to convert from logical cpu number to core number. The current APIs cpu_first_thread_in_core() and cpu_last_thread_in_core() returns logical CPU number while cpu_thread_to_core() returns core number or index which is not a logical CPU number. The new APIs are now clearly named to distinguish 'core number' versus first and last 'logical cpu number' in that core. The new APIs cpu_{first,last}_thread_sibling() work on logical cpu numbers. While cpu_first_thread_of_core() and cpu_core_index_of_thread() work on core index. Example usage: (4 threads per core system) cpu_first_thread_sibling(5) = 4 cpu_last_thread_sibling(5) = 7 cpu_core_index_of_thread(5) = 1 cpu_first_thread_of_core(1) = 4 cpu_core_index_of_thread() is used in cpu_to_drc_index() in the module and cpu_first_thread_of_core() is used in drc_index_to_cpu() in the module. Make API changes to few callers. Export symbols for use in modules. Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/smp.c')
-rw-r--r--arch/powerpc/kernel/smp.c19
1 files changed, 16 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 68034bb..9813605 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -466,7 +466,20 @@ out:
return id;
}
-/* Must be called when no change can occur to cpu_present_mask,
+/* Helper routines for cpu to core mapping */
+int cpu_core_index_of_thread(int cpu)
+{
+ return cpu >> threads_shift;
+}
+EXPORT_SYMBOL_GPL(cpu_core_index_of_thread);
+
+int cpu_first_thread_of_core(int core)
+{
+ return core << threads_shift;
+}
+EXPORT_SYMBOL_GPL(cpu_first_thread_of_core);
+
+/* Must be called when no change can occur to cpu_present_map,
* i.e. during cpu online or offline.
*/
static struct device_node *cpu_to_l2cache(int cpu)
@@ -514,7 +527,7 @@ int __devinit start_secondary(void *unused)
notify_cpu_starting(cpu);
set_cpu_online(cpu, true);
/* Update sibling maps */
- base = cpu_first_thread_in_core(cpu);
+ base = cpu_first_thread_sibling(cpu);
for (i = 0; i < threads_per_core; i++) {
if (cpu_is_offline(base + i))
continue;
@@ -600,7 +613,7 @@ int __cpu_disable(void)
return err;
/* Update sibling maps */
- base = cpu_first_thread_in_core(cpu);
+ base = cpu_first_thread_sibling(cpu);
for (i = 0; i < threads_per_core; i++) {
cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i));
cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu));
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