From: Paul Mackerras <paulus@samba.org>
To: linuxppc-dev@ozlabs.org
Subject: [PATCH] powerpc: Use ibm,chip-id property to compute cpu_core_mask if available
Date: Thu, 4 Jul 2013 13:05:06 +1000 [thread overview]
Message-ID: <20130704030506.GA2396@iris.ozlabs.ibm.com> (raw)
Some systems have an ibm,chip-id property in the cpu nodes in the
device tree. On these systems, we now use that to compute the
cpu_core_mask (i.e. the set of core siblings) rather than looking
at cache properties.
Signed-off-by: Paul Mackerras <paulus@samba.org>
---
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index b72d8c9..3b7a118 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -587,6 +587,32 @@ int cpu_first_thread_of_core(int core)
}
EXPORT_SYMBOL_GPL(cpu_first_thread_of_core);
+static void traverse_siblings_chip_id(int cpu, int add, int chipid)
+{
+ const struct cpumask *mask;
+ struct device_node *np;
+ int i, plen;
+ const int *prop;
+
+ mask = add ? cpu_online_mask : cpu_present_mask;
+ for_each_cpu(i, mask) {
+ np = of_get_cpu_node(i, NULL);
+ if (!np)
+ continue;
+ prop = of_get_property(np, "ibm,chip-id", &plen);
+ if (prop && plen == sizeof(int) && *prop == chipid) {
+ if (add) {
+ cpumask_set_cpu(cpu, cpu_core_mask(i));
+ cpumask_set_cpu(i, cpu_core_mask(cpu));
+ } else {
+ cpumask_clear_cpu(cpu, cpu_core_mask(i));
+ cpumask_clear_cpu(i, cpu_core_mask(cpu));
+ }
+ }
+ of_node_put(np);
+ }
+}
+
/* Must be called when no change can occur to cpu_present_mask,
* i.e. during cpu online or offline.
*/
@@ -611,14 +637,29 @@ static struct device_node *cpu_to_l2cache(int cpu)
static void traverse_core_siblings(int cpu, int add)
{
- struct device_node *l2_cache;
+ struct device_node *l2_cache, *np;
const struct cpumask *mask;
- int i;
+ int i, chip, plen;
+ const int *prop;
+
+ /* First see if we have ibm,chip-id properties in cpu nodes */
+ np = of_get_cpu_node(cpu, NULL);
+ if (np) {
+ chip = -1;
+ prop = of_get_property(np, "ibm,chip-id", &plen);
+ if (prop && plen == sizeof(int))
+ chip = *(int *)prop;
+ of_node_put(np);
+ if (chip >= 0) {
+ traverse_siblings_chip_id(cpu, add, chip);
+ return;
+ }
+ }
l2_cache = cpu_to_l2cache(cpu);
mask = add ? cpu_online_mask : cpu_present_mask;
for_each_cpu(i, mask) {
- struct device_node *np = cpu_to_l2cache(i);
+ np = cpu_to_l2cache(i);
if (!np)
continue;
if (np == l2_cache) {
next reply other threads:[~2013-07-04 3:05 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-04 3:05 Paul Mackerras [this message]
2013-08-09 7:22 ` [PATCH] powerpc: Use ibm, chip-id property to compute cpu_core_mask if available Vasant Hegde
2013-08-10 3:44 ` [PATCH] powerpc: Use ibm,chip-id " Paul Mackerras
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