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 <redacted>
Cc: Leo Yan <redacted>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <redacted>
---
  .../coresight/coresight-etm4x-core.c          | 29 ++++++++++---------
  include/linux/coresight.h                     | 12 ++++++++
  2 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 748d2ef53cb0..914ef6eb85d1 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;
  };

@@ -370,9 +369,17 @@ 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)
  {
-	if (etm4_hisi_match_pid(id))
+	/*
+	 * coresight_get_pid() fetches device PID from the iomem
+	 * register based accesses, which cannot be performed on
+	 * system instruction based devices.
+	 */