perf: Use device_show_string() helper for sysfs attributes

Deduplicate sysfs ->show() callbacks which expose a string at a static
memory location.  Use the newly introduced device_show_string() helper
in the driver core instead by declaring those sysfs attributes with
DEVICE_STRING_ATTR_RO().

No functional change intended.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/3a297850312b4ecb62d6872121de04496900f502.1713608122.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

4 files changed, 3 insertions, 40 deletions

diff --git a/drivers/perf/hisilicon/hisi_pcie_pmu.c b/drivers/perf/hisilicon/hisi_pcie_pmu.c
index 5d1f0e9fdb08..dfd1f448f3fc 100644
--- a/drivers/perf/hisilicon/hisi_pcie_pmu.c
+++ b/drivers/perf/hisilicon/hisi_pcie_pmu.c
@@ -99,16 +99,6 @@ HISI_PCIE_PMU_FILTER_ATTR(len_mode, config1, 11, 10);
 HISI_PCIE_PMU_FILTER_ATTR(port, config2, 15, 0);
 HISI_PCIE_PMU_FILTER_ATTR(bdf, config2, 31, 16);
 
-static ssize_t hisi_pcie_format_sysfs_show(struct device *dev, struct device_attribute *attr,
-					   char *buf)
-{
-	struct dev_ext_attribute *eattr;
-
-	eattr = container_of(attr, struct dev_ext_attribute, attr);
-
-	return sysfs_emit(buf, "%s\n", (char *)eattr->var);
-}
-
 static ssize_t hisi_pcie_event_sysfs_show(struct device *dev, struct device_attribute *attr,
 					  char *buf)
 {
@@ -120,8 +110,7 @@ static ssize_t hisi_pcie_event_sysfs_show(struct device *dev, struct device_attr
 
 #define HISI_PCIE_PMU_FORMAT_ATTR(_name, _format)                              \
 	(&((struct dev_ext_attribute[]){                                       \
-		{ .attr = __ATTR(_name, 0444, hisi_pcie_format_sysfs_show,     \
-				 NULL),                                        \
+		{ .attr = __ATTR(_name, 0444, device_show_string, NULL),       \
 		  .var = (void *)_format }                                     \
 	})[0].attr.attr)
 
diff --git a/drivers/perf/hisilicon/hisi_uncore_pmu.c b/drivers/perf/hisilicon/hisi_uncore_pmu.c
index 04031450d5fe..382c5567e4e2 100644
--- a/drivers/perf/hisilicon/hisi_uncore_pmu.c
+++ b/drivers/perf/hisilicon/hisi_uncore_pmu.c
@@ -23,20 +23,6 @@
 #define HISI_MAX_PERIOD(nr) (GENMASK_ULL((nr) - 1, 0))
 
 /*
- * PMU format attributes
- */
-ssize_t hisi_format_sysfs_show(struct device *dev,
-			       struct device_attribute *attr, char *buf)
-{
-	struct dev_ext_attribute *eattr;
-
-	eattr = container_of(attr, struct dev_ext_attribute, attr);
-
-	return sysfs_emit(buf, "%s\n", (char *)eattr->var);
-}
-EXPORT_SYMBOL_GPL(hisi_format_sysfs_show);
-
-/*
  * PMU event attributes
  */
 ssize_t hisi_event_sysfs_show(struct device *dev,
diff --git a/drivers/perf/hisilicon/hisi_uncore_pmu.h b/drivers/perf/hisilicon/hisi_uncore_pmu.h
index 92402aa69d70..25b2d43b72bf 100644
--- a/drivers/perf/hisilicon/hisi_uncore_pmu.h
+++ b/drivers/perf/hisilicon/hisi_uncore_pmu.h
@@ -33,7 +33,7 @@
 	})[0].attr.attr)
 
 #define HISI_PMU_FORMAT_ATTR(_name, _config)		\
-	HISI_PMU_ATTR(_name, hisi_format_sysfs_show, (void *)_config)
+	HISI_PMU_ATTR(_name, device_show_string, _config)
 #define HISI_PMU_EVENT_ATTR(_name, _config)		\
 	HISI_PMU_ATTR(_name, hisi_event_sysfs_show, (unsigned long)_config)
 
@@ -122,8 +122,6 @@ void hisi_uncore_pmu_enable(struct pmu *pmu);
 void hisi_uncore_pmu_disable(struct pmu *pmu);
 ssize_t hisi_event_sysfs_show(struct device *dev,
 			      struct device_attribute *attr, char *buf);
-ssize_t hisi_format_sysfs_show(struct device *dev,
-			       struct device_attribute *attr, char *buf);
 ssize_t hisi_cpumask_sysfs_show(struct device *dev,
 				struct device_attribute *attr, char *buf);
 int hisi_uncore_pmu_online_cpu(unsigned int cpu, struct hlist_node *node);
diff --git a/drivers/perf/hisilicon/hns3_pmu.c b/drivers/perf/hisilicon/hns3_pmu.c
index 16869bf5bf4c..6d9725bdff83 100644
--- a/drivers/perf/hisilicon/hns3_pmu.c
+++ b/drivers/perf/hisilicon/hns3_pmu.c
@@ -363,16 +363,6 @@ HNS3_PMU_FILTER_ATTR(global, config1, 52, 52);
 	HNS3_PMU_EVT_PPS_##_name##_TIME,				\
 	HNS3_PMU_FILTER_INTR_##_name})
 
-static ssize_t hns3_pmu_format_show(struct device *dev,
-				    struct device_attribute *attr, char *buf)
-{
-	struct dev_ext_attribute *eattr;
-
-	eattr = container_of(attr, struct dev_ext_attribute, attr);
-
-	return sysfs_emit(buf, "%s\n", (char *)eattr->var);
-}
-
 static ssize_t hns3_pmu_event_show(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
@@ -421,7 +411,7 @@ static ssize_t hns3_pmu_filter_mode_show(struct device *dev,
 	})[0].attr.attr)
 
 #define HNS3_PMU_FORMAT_ATTR(_name, _format) \
-	HNS3_PMU_ATTR(_name, hns3_pmu_format_show, (void *)_format)
+	HNS3_PMU_ATTR(_name, device_show_string, _format)
 #define HNS3_PMU_EVENT_ATTR(_name, _event) \
 	HNS3_PMU_ATTR(_name, hns3_pmu_event_show, (void *)_event)
 #define HNS3_PMU_FLT_MODE_ATTR(_name, _event) \