On 23/01/2024 05:45, Anshuman Khandual wrote:
Instead of using AMBA private data field, extract the device name from AMBA
pid based table lookup using new coresight_get_uci_data_from_amba() helper.
Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Cc: Mike Leach <mike.leach@xxxxxxxxxx>
Cc: James Clark <james.clark@xxxxxxx>
Cc: coresight@xxxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-stm32@xxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
drivers/hwtracing/coresight/coresight-priv.h | 10 ++++++++++
drivers/hwtracing/coresight/coresight-stm.c | 14 +++++++++++++-
2 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index 767076e07970..68cbb036cec8 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -221,6 +221,16 @@ static inline void *coresight_get_uci_data(const struct amba_id *id)
return uci_id->data;
}
+static inline void *coresight_get_uci_data_from_amba(const struct amba_id *table, u32 pid)
+{
+ while (table->mask) {
+ if ((table->id & table->mask) == pid)
Why are we masking table->id ? table->id is a static value that the
driver wants to check for "variants" of a given device. The table->mask
is there to filter out the "irrelevant" bits of the PID that we read
from the device. So this should instead be:
if ((table->mask & pid) == table->id)
+ return coresight_get_uci_data(table);
+ table++;
+ };
+ return NULL;
+}
+
void coresight_release_platform_data(struct coresight_device *csdev,
struct device *dev,
struct coresight_platform_data *pdata);
diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
index a1c27c901ad1..9cdca4f86cab 100644
--- a/drivers/hwtracing/coresight/coresight-stm.c
+++ b/drivers/hwtracing/coresight/coresight-stm.c
@@ -804,6 +804,18 @@ static void stm_init_generic_data(struct stm_drvdata *drvdata,
drvdata->stm.set_options = stm_generic_set_options;
}
+#define STM_AMBA_MASK 0xfffff
+
+static const struct amba_id stm_ids[];
+
+static char *stm_csdev_name(struct coresight_device *csdev)
+{
+ u32 stm_pid = coresight_get_pid(&csdev->access) & STM_AMBA_MASK;
Similar to above:
Why do we apply a "custom" mask to the PID and later check the PID with
that of the table->pid.
The way it is supposed work is :
(table->mask & dev_pid) == table->pid
the table->mask is there for a reason: i.e., to get the relevant bits
from the device_pid and compare it against "the" expected value
(table->pid).
Suzuki
+ void *uci_data = coresight_get_uci_data_from_amba(stm_ids, stm_pid);
+
+ return uci_data ? (char *)uci_data : "STM";
+}
+
static int stm_probe(struct amba_device *adev, const struct amba_id *id)
{
int ret, trace_id;
@@ -900,7 +912,7 @@ static int stm_probe(struct amba_device *adev, const struct amba_id *id)
pm_runtime_put(&adev->dev);
dev_info(&drvdata->csdev->dev, "%s initialized\n",
- (char *)coresight_get_uci_data(id));
+ stm_csdev_name(drvdata->csdev));
return 0;
cs_unregister:
