On Tue, Feb 11, 2025 at 10:39:39AM +0000, 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.
Signed-off-by: James Clark james.clark@linaro.org
I checked the latest PSCI spec DEN0022F.b, which has no change for for only using lowest two bits in claim register.
Reviewed-by: Leo Yan leo.yan@arm.com
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 a669872b4118..7b53165c93af 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -129,7 +129,8 @@ coresight_find_out_connection(struct coresight_device *csdev,
static inline u32 coresight_read_claim_tags(struct csdev_access *csa) {
return csdev_access_relaxed_read32(csa, CORESIGHT_CLAIMCLR);
return FIELD_GET(CORESIGHT_CLAIM_MASK,csdev_access_relaxed_read32(csa, CORESIGHT_CLAIMCLR));}
static inline bool coresight_is_claimed_self_hosted(struct csdev_access *csa) diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h index 05f891ca6b5c..cc7ff1e36ef4 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)
#define TIMEOUT_US 100
2.34.1
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