On 17/10/17 17:20, Suzuki K Poulose wrote:
On 17/10/17 17:11, Will Deacon wrote:
On Tue, Oct 17, 2017 at 04:24:23PM +0100, Mark Rutland wrote:
On Tue, Oct 10, 2017 at 11:33:00AM +0100, Suzuki K Poulose wrote:
Make use of the new generic helper to convert an of_node of a CPU
to the logical CPU id in parsing the topology.
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Leo Yan <leo.yan@xxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
This looks sane to me, but it will need an ack from Will or Catalin.
FWIW:
Acked-by: Mark Rutland <mark.rutland@xxxxxxx>
Thanks,
Mark.
---
arch/arm64/kernel/topology.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
index 8d48b233e6ce..21868530018e 100644
--- a/arch/arm64/kernel/topology.c
+++ b/arch/arm64/kernel/topology.c
@@ -37,18 +37,14 @@ static int __init get_cpu_for_node(struct device_node *node)
if (!cpu_node)
return -1;
- for_each_possible_cpu(cpu) {
- if (of_get_cpu_node(cpu, NULL) == cpu_node) {
- topology_parse_cpu_capacity(cpu_node, cpu);
- of_node_put(cpu_node);
- return cpu;
- }
- }
-
- pr_crit("Unable to find CPU node for %pOF\n", cpu_node);
+ cpu = of_cpu_node_to_id(cpu_node);
+ if (cpu >= 0)
+ topology_parse_cpu_capacity(cpu_node, cpu);
+ else
+ pr_crit("Unable to find CPU node for %pOF\n", cpu_node);
of_node_put(cpu_node);
This of_node_put is confusing me. Since of_cpu_node_to_id appears to be
balanced with its use of the node refcount, is this one intended to pair
with the earlier call to of_parse_phandle?
Yes.
If so, does that mainline is
currently broken here because it doesn't drop the refcount twice for the
matching node?
No. This of_node_put is for the failure case where we couldn't match a CPU.
In the success case, it is dropped just before we return the result within
the loop.
As we discussed offline, there is indeed a missing of_node_put() for all the
nodes we loop through to match. But with this change, we have fixed that.
And I don't think it is worth sending to stable.
Cheers
Suzuki
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