@@ -133,16 +133,6 @@ static inline u32 coresight_read_claim_tags(struct csdev_access *csa)
csdev_access_relaxed_read32(csa, CORESIGHT_CLAIMCLR));
}
-static inline bool coresight_is_claimed_self_hosted(struct csdev_access *csa)
-{
- return coresight_read_claim_tags(csa) == CORESIGHT_CLAIM_SELF_HOSTED;
-}
-
-static inline bool coresight_is_claimed_any(struct coresight_device *csdev)
-{
- return coresight_read_claim_tags(&csdev->access) != 0;
-}
-
static inline void coresight_set_self_claim_tag(struct csdev_access *csa)
{
csdev_access_relaxed_write32(csa, CORESIGHT_CLAIM_SELF_HOSTED,
@@ -169,18 +159,40 @@ static inline void coresight_clear_self_claim_tag(struct csdev_access *csa)
*/
int coresight_claim_device_unlocked(struct coresight_device *csdev)
{
+ int tag;
+ struct csdev_access *csa;
+
if (WARN_ON(!csdev))
return -EINVAL;
- if (coresight_is_claimed_any(csdev))
+ csa = &csdev->access;
+ tag = coresight_read_claim_tags(csa);
+
+ switch (tag) {
+ case CORESIGHT_CLAIM_FREE:
+ coresight_set_self_claim_tag(csa);
+ if (coresight_read_claim_tags(csa) == CORESIGHT_CLAIM_SELF_HOSTED)
+ return 0;
+
+ /* There was a race setting the tag, clean up and fail */
+ coresight_clear_self_claim_tag(csa);
return -EBUSY;
- coresight_set_self_claim_tag(&csdev->access);
- if (coresight_is_claimed_self_hosted(&csdev->access))
- return 0;
- /* There was a race setting the tag, clean up and fail */
- coresight_clear_self_claim_tag(&csdev->access);
- return -EBUSY;
+ case CORESIGHT_CLAIM_EXTERNAL:
+ /* External debug is an expected state, so log and report BUSY */
+ dev_dbg(&csdev->dev, "Busy: Claimed by external debugger");
+ return -EBUSY;
+
+ default:
+ case CORESIGHT_CLAIM_SELF_HOSTED:
+ case CORESIGHT_CLAIM_INVALID:
+ /*
+ * Warn here because we clear a lingering self hosted tag
+ * on probe, so other tag combinations are impossible.
+ */
+ dev_err_once(&csdev->dev, "Invalid claim tag state: %x", tag);
+ return -EBUSY;
+ }
}
EXPORT_SYMBOL_GPL(coresight_claim_device_unlocked);
@@ -205,7 +217,7 @@ EXPORT_SYMBOL_GPL(coresight_claim_device);
*/
void coresight_disclaim_device_unlocked(struct csdev_access *csa)
{
- if (coresight_is_claimed_self_hosted(csa))
+ if (coresight_read_claim_tags(csa) == CORESIGHT_CLAIM_SELF_HOSTED)
coresight_clear_self_claim_tag(csa);
else
/*
@@ -36,7 +36,10 @@ extern const struct device_type coresight_dev_type[];
* 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 CORESIGHT_CLAIM_FREE 0
+#define CORESIGHT_CLAIM_EXTERNAL 1
+#define CORESIGHT_CLAIM_SELF_HOSTED 2
+#define CORESIGHT_CLAIM_INVALID 3
#define TIMEOUT_US 100
#define BMVAL(val, lsb, msb) ((val & GENMASK(msb, lsb)) >> lsb)
Add a dev_dbg() message so that external debugger conflicts are more visible. There are multiple reasons for -EBUSY so a message for this particular one could be helpful. Add errors for and enumerate all the other cases that are impossible. Signed-off-by: James Clark <james.clark@linaro.org> --- drivers/hwtracing/coresight/coresight-core.c | 48 ++++++++++++-------- drivers/hwtracing/coresight/coresight-priv.h | 5 +- 2 files changed, 34 insertions(+), 19 deletions(-)