[PATCH v3 19/26] coresight: etm4x: Detect access early on the target CPU

Suzuki K Poulose
2020-10-28T22:10:49Z

In preparation to detect the support for system instruction
support, move the detection of the device access to the target
CPU.

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
.../coresight/coresight-etm4x-core.c | 45 ++++++++++++++++---
1 file changed, 40 insertions(+), 5 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index f038bb10bc78..308674ab746c 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -56,6 +56,11 @@ static u64 etm4_get_access_type(struct etmv4_config *config);

static enum cpuhp_state hp_online;

+struct etm_init_arg {
+ struct etmv4_drvdata *drvdata;
+ struct csdev_access *csa;
+};
+
u64 etm4x_sysreg_read(struct csdev_access *csa,
u32 offset,
bool _relaxed,
@@ -669,6 +674,22 @@ static const struct coresight_ops etm4_cs_ops = {
.source_ops = &etm4_source_ops,
};

+static bool etm_init_iomem_access(struct etmv4_drvdata *drvdata,
+ struct csdev_access *csa)
+{
+ *csa = CSDEV_ACCESS_IOMEM(drvdata->base);
+ return true;
+}
+
+static bool etm_init_csdev_access(struct etmv4_drvdata *drvdata,
+ struct csdev_access *csa)
+{
+ if (drvdata->base)
+ return etm_init_iomem_access(drvdata, csa);
+
+ return false;
+}
+
static void etm4_init_arch_data(void *info)
{
u32 etmidr0;
@@ -677,11 +698,22 @@ static void etm4_init_arch_data(void *info)
u32 etmidr3;
u32 etmidr4;
u32 etmidr5;
- struct etmv4_drvdata *drvdata = info;
- struct csdev_access tmp_csa = CSDEV_ACCESS_IOMEM(drvdata->base);
- struct csdev_access *csa = &tmp_csa;
+ struct etm_init_arg *init_arg = info;
+ struct etmv4_drvdata *drvdata;
+ struct csdev_access *csa;
int i;

+ drvdata = init_arg->drvdata;
+ csa = init_arg->csa;
+
+ /*
+ * If we are unable to detect the access mechanism,
+ * or unable to detect the trace unit type, fail
+ * early.
+ */
+ if (!etm_init_csdev_access(drvdata, csa))
+ return;
+
/* Make sure all registers are accessible */
etm4_os_unlock_csa(drvdata, csa);
etm4_cs_unlock(drvdata, csa);
@@ -1524,6 +1556,7 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
struct etmv4_drvdata *drvdata;
struct resource *res = &adev->res;
struct coresight_desc desc = { 0 };
+ struct etm_init_arg init_arg = { 0 };

drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
if (!drvdata)
@@ -1551,7 +1584,6 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
return PTR_ERR(base);

drvdata->base = base;
- desc.access = CSDEV_ACCESS_IOMEM(base);

spin_lock_init(&drvdata->spinlock);

@@ -1563,8 +1595,11 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
if (!desc.name)
return -ENOMEM;

+ init_arg.drvdata = drvdata;
+ init_arg.csa = &desc.access;
+
if (smp_call_function_single(drvdata->cpu,
- etm4_init_arch_data, drvdata, 1))
+ etm4_init_arch_data, &init_arg, 1))
dev_err(dev, "ETM arch init failed\n");

if (etm4_arch_supported(drvdata->arch) == false)
--
2.24.1