[PATCH 1/2] powerpc: Pull out cpu_core_mask updates into a separate function

Subsystems: linux for powerpc (32-bit and 64-bit), the rest · Maintainers: Madhavan Srinivasan, Linus Torvalds

STALE4823d

4 messages, 2 authors, 2013-08-12 · open the first message on its own page

[PATCH 1/2] powerpc: Pull out cpu_core_mask updates into a separate function

From: Paul Mackerras <hidden>
Date: 2013-08-10 03:45:30

This factors out the details of updating cpu_core_mask into a separate
function, to make it easier to change how the mask is calculated later.
This makes no functional change.

Signed-off-by: Paul Mackerras <redacted>
---
 arch/powerpc/kernel/smp.c | 56 +++++++++++++++++++++++------------------------
 1 file changed, 28 insertions(+), 28 deletions(-)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 38b0ba6..663cefd 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c

@@ -609,11 +609,36 @@ static struct device_node *cpu_to_l2cache(int cpu)
 	return cache;
 }
 
+static void traverse_core_siblings(int cpu, int add)
+{
+	struct device_node *l2_cache;
+	const struct cpumask *mask;
+	int i;
+
+	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);
+		if (!np)
+			continue;
+		if (np == l2_cache) {
+			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);
+	}
+	of_node_put(l2_cache);
+}
+
 /* Activate a secondary processor. */
 void start_secondary(void *unused)
 {
 	unsigned int cpu = smp_processor_id();
-	struct device_node *l2_cache;
 	int i, base;
 
 	atomic_inc(&init_mm.mm_count);

@@ -652,18 +677,7 @@ void start_secondary(void *unused)
 		cpumask_set_cpu(cpu, cpu_core_mask(base + i));
 		cpumask_set_cpu(base + i, cpu_core_mask(cpu));
 	}
-	l2_cache = cpu_to_l2cache(cpu);
-	for_each_online_cpu(i) {
-		struct device_node *np = cpu_to_l2cache(i);
-		if (!np)
-			continue;
-		if (np == l2_cache) {
-			cpumask_set_cpu(cpu, cpu_core_mask(i));
-			cpumask_set_cpu(i, cpu_core_mask(cpu));
-		}
-		of_node_put(np);
-	}
-	of_node_put(l2_cache);
+	traverse_core_siblings(cpu, 1);
 
 	smp_wmb();
 	notify_cpu_starting(cpu);

@@ -719,7 +733,6 @@ int arch_sd_sibling_asym_packing(void)
 #ifdef CONFIG_HOTPLUG_CPU
 int __cpu_disable(void)
 {
-	struct device_node *l2_cache;
 	int cpu = smp_processor_id();
 	int base, i;
 	int err;

@@ -739,20 +752,7 @@ int __cpu_disable(void)
 		cpumask_clear_cpu(cpu, cpu_core_mask(base + i));
 		cpumask_clear_cpu(base + i, cpu_core_mask(cpu));
 	}
-
-	l2_cache = cpu_to_l2cache(cpu);
-	for_each_present_cpu(i) {
-		struct device_node *np = cpu_to_l2cache(i);
-		if (!np)
-			continue;
-		if (np == l2_cache) {
-			cpumask_clear_cpu(cpu, cpu_core_mask(i));
-			cpumask_clear_cpu(i, cpu_core_mask(cpu));
-		}
-		of_node_put(np);
-	}
-	of_node_put(l2_cache);
-
+	traverse_core_siblings(cpu, 0);
 
 	return 0;
 }

-- 
1.8.3.1

[PATCH 2/2] powerpc: Use ibm,chip-id property to compute cpu_core_mask if available

From: Paul Mackerras <hidden>
Date: 2013-08-10 03:46:15

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 <redacted>
---
 arch/powerpc/kernel/smp.c | 47 ++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 44 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 663cefd..076977c 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) {

-- 
1.8.3.1

Re: [PATCH 1/2] powerpc: Pull out cpu_core_mask updates into a separate function

From: Stephen Rothwell <hidden>
Date: 2013-08-12 04:41:05

Hi Paul,

On Sat, 10 Aug 2013 13:45:30 +1000 Paul Mackerras [off-list ref] wrote:

quoted hunk

This factors out the details of updating cpu_core_mask into a separate
function, to make it easier to change how the mask is calculated later.
This makes no functional change.

Signed-off-by: Paul Mackerras <redacted>
---
 arch/powerpc/kernel/smp.c | 56 +++++++++++++++++++++++------------------------
 1 file changed, 28 insertions(+), 28 deletions(-)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 38b0ba6..663cefd 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c

@@ -609,11 +609,36 @@ static struct device_node *cpu_to_l2cache(int cpu)
 	return cache;
 }
 
+static void traverse_core_siblings(int cpu, int add)

This "add" parameter is only used as a boolean, so should be declared
that way.

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au

Re: [PATCH 2/2] powerpc: Use ibm,chip-id property to compute cpu_core_mask if available

From: Stephen Rothwell <hidden>
Date: 2013-08-12 05:02:09

Hi Paul,

On Sat, 10 Aug 2013 13:46:15 +1000 Paul Mackerras [off-list ref] wrote:

+static void traverse_siblings_chip_id(int cpu, int add, int chipid)

Again, the "add is a boolean.

quoted hunk

+{
+	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) {

                                                   ^^^^^
You should be using of_read_number(), I think.

quoted hunk

 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;

Here as well.

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au

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