[PATCH 3/7] coresight: etm4x: Drop pid argument from etm4_probe()

Anshuman Khandual
2023-03-17T03:06:12Z

Coresight device pid can be retrieved from its iomem base address, which is
stored in 'struct etm4x_drvdata'. This drops pid argument from etm4_probe()
and 'struct etm4_init_arg'. Instead etm4_check_arch_features() derives the
coresight device pid with a new helper coresight_get_pid(), right before it
is consumed in etm4_hisi_match_pid().

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
.../coresight/coresight-etm4x-core.c | 19 +++++++------------
include/linux/coresight.h | 12 ++++++++++++
2 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 5d77571a8df9..a4c138e67920 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -66,7 +66,6 @@ static u64 etm4_get_access_type(struct etmv4_config *config);
static enum cpuhp_state hp_online;

struct etm4_init_arg {
- unsigned int pid;
struct device *dev;
struct csdev_access *csa;
};
@@ -370,8 +369,10 @@ static void etm4_disable_arch_specific(struct etmv4_drvdata *drvdata)
}

static void etm4_check_arch_features(struct etmv4_drvdata *drvdata,
- unsigned int id)
+ struct csdev_access *csa)
{
+ unsigned int id = coresight_get_pid(csa);
+
if (etm4_hisi_match_pid(id))
set_bit(ETM4_IMPDEF_HISI_CORE_COMMIT, drvdata->arch_features);
}
@@ -1165,7 +1166,7 @@ static void etm4_init_arch_data(void *info)
etm4_os_unlock_csa(drvdata, csa);
etm4_cs_unlock(drvdata, csa);

- etm4_check_arch_features(drvdata, init_arg->pid);
+ etm4_check_arch_features(drvdata, csa);

/* find all capabilities of the tracing unit */
etmidr0 = etm4x_relaxed_read32(csa, TRCIDR0);
@@ -2048,7 +2049,7 @@ static int etm4_add_coresight_dev(struct etm4_init_arg *init_arg)
return 0;
}

-static int etm4_probe(struct device *dev, u32 etm_pid)
+static int etm4_probe(struct device *dev)
{
struct etmv4_drvdata *drvdata = dev_get_drvdata(dev);
struct csdev_access access = { 0 };
@@ -2077,7 +2078,6 @@ static int etm4_probe(struct device *dev, u32 etm_pid)

init_arg.dev = dev;
init_arg.csa = &access;
- init_arg.pid = etm_pid;

/*
* Serialize against CPUHP callbacks to avoid race condition
@@ -2124,7 +2124,7 @@ static int etm4_probe_amba(struct amba_device *adev, const struct amba_id *id)

drvdata->base = base;
dev_set_drvdata(dev, drvdata);
- ret = etm4_probe(dev, id->id);
+ ret = etm4_probe(dev);
if (!ret)
pm_runtime_put(&adev->dev);

@@ -2146,12 +2146,7 @@ static int etm4_probe_platform_dev(struct platform_device *pdev)
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);

- /*
- * System register based devices could match the
- * HW by reading appropriate registers on the HW
- * and thus we could skip the PID.
- */
- ret = etm4_probe(&pdev->dev, 0);
+ ret = etm4_probe(&pdev->dev);

pm_runtime_put(&pdev->dev);
return ret;
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index f19a47b9bb5a..f85b041ea475 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -370,6 +370,18 @@ static inline u32 csdev_access_relaxed_read32(struct csdev_access *csa,
return csa->read(offset, true, false);
}

+#define CORESIGHT_PIDRn(i) (0xFE0 + ((i) * 4))
+
+static inline u32 coresight_get_pid(struct csdev_access *csa)
+{
+ u32 i, pid = 0;
+
+ for (i = 0; i < 4; i++)
+ pid |= csdev_access_relaxed_read32(csa, CORESIGHT_PIDRn(i)) << (i * 8);
+
+ return pid;
+}
+
static inline u64 csdev_access_relaxed_read_pair(struct csdev_access *csa,
u32 lo_offset, u32 hi_offset)
{
--
2.25.1