Re: [v3 2/5] coresight: refactor with function of_coresight_get_cpu

[Suzuki K Poulose]

On 09/03/17 11:01, Suzuki K Poulose wrote:

On 03/03/17 06:00, Leo Yan wrote:

This is refactor to add function of_coresight_get_cpu(), so it's used to
retrieve CPU id for coresight component. Finally can use it as a common
function for multiple places.

Suggested-by: Mathieu Poirier <mathieu.poir...@linaro.org>
Signed-off-by: Leo Yan <leo....@linaro.org>
---
 drivers/hwtracing/coresight/of_coresight.c | 37 ++++++++++++++++++++----------
 include/linux/coresight.h                  |  2 ++
 2 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/drivers/hwtracing/coresight/of_coresight.c 
b/drivers/hwtracing/coresight/of_coresight.c
index 629e031..d9a12fb 100644
--- a/drivers/hwtracing/coresight/of_coresight.c
+++ b/drivers/hwtracing/coresight/of_coresight.c
@@ -101,14 +101,36 @@ static int of_coresight_alloc_memory(struct device *dev,
        return 0;
 }

+int of_coresight_get_cpu(struct device_node *node)
+{
+       int cpu;
+       struct device_node *dn;
+
+       dn = of_parse_phandle(node, "cpu", 0);
+
+       /* Affinity defaults to CPU0 */
+       if (!dn)
+               return 0;
+
+       for_each_possible_cpu(cpu) {
+               if (dn == of_get_cpu_node(cpu, NULL)) {

We should do of_node_put() on the node returned by of_get_cpu_node,
and I accept that this was there before the refactoring. We could do
something like :


----8>------



[PATCH] coresight: of_coresight_get_cpu: Add missing of_node_put

The of_coresight_get_cpu iterates over the possible CPU nodes
to find a given cpu phandle. However it does not drop the reference
to the node pointer returned by the of_get_cpu_node.

Cc: Leo Yan <leo....@linaro.org>
Cc: Mathieu Poirier <mathieu.poir...@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poul...@arm.com>
---
 drivers/hwtracing/coresight/of_coresight.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/hwtracing/coresight/of_coresight.c 
b/drivers/hwtracing/coresight/of_coresight.c
index d9a12fb..8c6f4a0 100644
--- a/drivers/hwtracing/coresight/of_coresight.c
+++ b/drivers/hwtracing/coresight/of_coresight.c
@@ -104,7 +104,8 @@ static int of_coresight_alloc_memory(struct device *dev,
 int of_coresight_get_cpu(struct device_node *node)
 {
        int cpu;
-       struct device_node *dn;
+       bool found;
+       struct device_node *dn, *np;

        dn = of_parse_phandle(node, "cpu", 0);

@@ -113,15 +114,16 @@ int of_coresight_get_cpu(struct device_node *node)
                return 0;

        for_each_possible_cpu(cpu) {
-               if (dn == of_get_cpu_node(cpu, NULL)) {
-                       of_node_put(dn);
-                       return cpu;
-               }
+               np = of_get_cpu_node(cpu, NULL);
+               found = (dn == np);
+               of_node_put(np);
+               if (found)
+                       break;
        }

-       /* Affinity to CPU0 if no cpu nodes are found */
        of_node_put(dn);
-       return 0;
+       /* Affinity to CPU0 if no cpu nodes are found */
+       return cpu_possible(cpu) ? cpu : 0;

This could be even :
        return found ? cpu : 0;

Suzuki