On 20/03/2025 14:34, James Clark wrote:
The use of the whole register and == could break the claim mechanism if any of the other bits are used in the future. The referenced doc "PSCI - ARM DEN 0022D" also says to only read and clear the bottom two bits.
Use FIELD_GET() to extract only the relevant part.
Reviewed-by: Leo Yan leo.yan@arm.com Signed-off-by: James Clark james.clark@linaro.org
drivers/hwtracing/coresight/coresight-core.c | 3 ++- drivers/hwtracing/coresight/coresight-priv.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 8471aefeac76..26d149a4c579 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -131,7 +131,8 @@ coresight_find_out_connection(struct coresight_device *csdev, static inline u32 coresight_read_claim_tags(struct coresight_device *csdev) {
- return csdev_access_relaxed_read32(&csdev->access, CORESIGHT_CLAIMCLR);
- return FIELD_GET(CORESIGHT_CLAIM_MASK,
csdev_access_relaxed_read32(&csdev->access, CORESIGHT_CLAIMCLR));static inline bool coresight_is_claimed_self_hosted(struct coresight_device *csdev) diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h index 82644aff8d2b..38bb4e8b50ef 100644 --- a/drivers/hwtracing/coresight/coresight-priv.h +++ b/drivers/hwtracing/coresight/coresight-priv.h @@ -35,6 +35,7 @@ extern const struct device_type coresight_dev_type[];
- Coresight device CLAIM protocol.
- See PSCI - ARM DEN 0022D, Section: 6.8.1 Debug and Trace save and restore.
*/ +#define CORESIGHT_CLAIM_MASK GENMASK(1, 0) #define CORESIGHT_CLAIM_SELF_HOSTED BIT(1)
I am checking with the Arm CoreSight architects on this. This is problematic, if another agent is assigned, say BIT(2) and we wouldn't forward compatible.
Suzuki
#define TIMEOUT_US 100