[PATCH v2 0/3] driver core: Constify the signature of device_show/store_*()

[PATCH v2 0/3] driver core: Constify the signature of device_show/store_*()

[Thomas Weißschuh]

Prepare for the constification of 'struct dev_ext_attribute' instances
by changing the signature of the standard callback functions.
The first two patches prepare some drivers to handle both the const and
non-const callback variants.

Intended for the driver-core tree.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
Changes in v2:
- Rebase on v7.3-rc1.
- Cover a few more drivers in drivers/perf/.
- Link to v1: https://patch.msgid.link/20260714-sysfs-const-attr-dev_ext_attr-v1-0-6b2c0435d621@weissschuh.net

---
Thomas Weißschuh (3):
      x86/mce: Use __DEVICE_ATTR() macro to initialize dev_ext_attribute
      drivers: perf: Use __DEVICE_ATTR() macro to initialize dev_ext_attribute
      driver core: Constify the signature of device_show/store_*()

 arch/powerpc/perf/hv-24x7.c                 |  2 +-
 arch/x86/kernel/cpu/mce/core.c              |  6 +++---
 drivers/base/core.c                         | 30 ++++++++++++++---------------
 drivers/perf/alibaba_uncore_drw_pmu.c       |  2 +-
 drivers/perf/arm-cci.c                      |  2 +-
 drivers/perf/arm-ccn.c                      |  2 +-
 drivers/perf/arm_cspmu/arm_cspmu.h          |  2 +-
 drivers/perf/arm_dsu_pmu.c                  |  2 +-
 drivers/perf/arm_spe_pmu.c                  |  6 +++---
 drivers/perf/cxl_pmu.c                      | 10 +++++-----
 drivers/perf/fsl_imx8_ddr_perf.c            |  2 +-
 drivers/perf/fujitsu_uncore_pmu.c           |  2 +-
 drivers/perf/hisilicon/hisi_pcie_pmu.c      |  2 +-
 drivers/perf/hisilicon/hisi_uncore_pmu.h    |  6 +++---
 drivers/perf/hisilicon/hns3_pmu.c           |  6 +++---
 drivers/perf/nvidia_t410_c2c_pmu.c          |  2 +-
 drivers/perf/nvidia_t410_cmem_latency_pmu.c | 12 ++++++------
 drivers/perf/qcom_l3_pmu.c                  |  8 ++++----
 drivers/perf/starfive_starlink_pmu.c        |  2 +-
 drivers/perf/xgene_pmu.c                    |  2 +-
 include/linux/device.h                      | 14 +++++++-------
 21 files changed, 61 insertions(+), 61 deletions(-)
---
base-commit: cee9395acd8043be0644b25c34bfa86623f2b935
change-id: 20260712-sysfs-const-attr-dev_ext_attr-dbf669fdfd4e

Best regards,
--  
Thomas Weißschuh <linux@weissschuh.net>

[PATCH v2 1/3] x86/mce: Use __DEVICE_ATTR() macro to initialize dev_ext_attribute

[Thomas Weißschuh]

The upcoming constification of the device_show_int() and
device_show_bool() signatures requires the users to handle the
transition automatically.

Switch to the __DEVICE_ATTR() macro which can do this.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 arch/x86/kernel/cpu/mce/core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index ab469605fc89..d67f3b6b83d8 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -2621,17 +2621,17 @@ static DEVICE_BOOL_ATTR(dont_log_ce, 0644, mca_cfg.dont_log_ce);
 static DEVICE_BOOL_ATTR(print_all, 0644, mca_cfg.print_all);
 
 static struct dev_ext_attribute dev_attr_check_interval = {
-	__ATTR(check_interval, 0644, device_show_int, store_int_with_restart),
+	__DEVICE_ATTR(check_interval, 0644, device_show_int, store_int_with_restart),
 	&check_interval
 };
 
 static struct dev_ext_attribute dev_attr_ignore_ce = {
-	__ATTR(ignore_ce, 0644, device_show_bool, set_ignore_ce),
+	__DEVICE_ATTR(ignore_ce, 0644, device_show_bool, set_ignore_ce),
 	&mca_cfg.ignore_ce
 };
 
 static struct dev_ext_attribute dev_attr_cmci_disabled = {
-	__ATTR(cmci_disabled, 0644, device_show_bool, set_cmci_disabled),
+	__DEVICE_ATTR(cmci_disabled, 0644, device_show_bool, set_cmci_disabled),
 	&mca_cfg.cmci_disabled
 };
 

-- 
2.55.0

[PATCH v2 2/3] drivers: perf: Use __DEVICE_ATTR() macro to initialize dev_ext_attribute

[Thomas Weißschuh]

The upcoming constification of the device_show_*() callback
signatures requires the users to handle the transition automatically.

Switch to the __DEVICE_ATTR() macro which can do this.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 drivers/perf/alibaba_uncore_drw_pmu.c       |  2 +-
 drivers/perf/arm-cci.c                      |  2 +-
 drivers/perf/arm-ccn.c                      |  2 +-
 drivers/perf/arm_cspmu/arm_cspmu.h          |  2 +-
 drivers/perf/arm_dsu_pmu.c                  |  2 +-
 drivers/perf/arm_spe_pmu.c                  |  6 +++---
 drivers/perf/cxl_pmu.c                      | 10 +++++-----
 drivers/perf/fsl_imx8_ddr_perf.c            |  2 +-
 drivers/perf/fujitsu_uncore_pmu.c           |  2 +-
 drivers/perf/hisilicon/hisi_pcie_pmu.c      |  2 +-
 drivers/perf/hisilicon/hisi_uncore_pmu.h    |  6 +++---
 drivers/perf/hisilicon/hns3_pmu.c           |  6 +++---
 drivers/perf/nvidia_t410_c2c_pmu.c          |  2 +-
 drivers/perf/nvidia_t410_cmem_latency_pmu.c | 12 ++++++------
 drivers/perf/qcom_l3_pmu.c                  |  8 ++++----
 drivers/perf/starfive_starlink_pmu.c        |  2 +-
 drivers/perf/xgene_pmu.c                    |  2 +-
 17 files changed, 35 insertions(+), 35 deletions(-)

diff --git a/drivers/perf/alibaba_uncore_drw_pmu.c b/drivers/perf/alibaba_uncore_drw_pmu.c
index fc934bccf4a6..5b6d3a4736da 100644
--- a/drivers/perf/alibaba_uncore_drw_pmu.c
+++ b/drivers/perf/alibaba_uncore_drw_pmu.c
@@ -135,7 +135,7 @@ static ssize_t ali_drw_pmu_event_show(struct device *dev,
 
 #define ALI_DRW_PMU_ATTR(_name, _func, _config)                            \
 		(&((struct dev_ext_attribute[]) {                               \
-				{ __ATTR(_name, 0444, _func, NULL), (void *)_config }   \
+				{ __DEVICE_ATTR(_name, 0444, _func, NULL), (void *)_config }   \
 		})[0].attr.attr)
 
 #define ALI_DRW_PMU_FORMAT_ATTR(_name, _config)            \
diff --git a/drivers/perf/arm-cci.c b/drivers/perf/arm-cci.c
index f0ef0a679e74..71035227f58b 100644
--- a/drivers/perf/arm-cci.c
+++ b/drivers/perf/arm-cci.c
@@ -132,7 +132,7 @@ static ssize_t __maybe_unused cci_pmu_event_show(struct device *dev,
 
 #define CCI_EXT_ATTR_ENTRY(_name, _func, _config) 				\
 	&((struct dev_ext_attribute[]) {					\
-		{ __ATTR(_name, S_IRUGO, _func, NULL), (void *)_config }	\
+		{ __DEVICE_ATTR(_name, S_IRUGO, _func, NULL), (void *)_config }	\
 	})[0].attr.attr
 
 #define CCI_FORMAT_EXT_ATTR_ENTRY(_name, _config) \
diff --git a/drivers/perf/arm-ccn.c b/drivers/perf/arm-ccn.c
index c40da3450c8f..e3411bdf5c7c 100644
--- a/drivers/perf/arm-ccn.c
+++ b/drivers/perf/arm-ccn.c
@@ -216,7 +216,7 @@ static void arm_ccn_pmu_config_set(u64 *config, u32 node_xp, u32 type, u32 port)
 
 #define CCN_FORMAT_ATTR(_name, _config) \
 	struct dev_ext_attribute arm_ccn_pmu_format_attr_##_name = \
-			{ __ATTR(_name, S_IRUGO, device_show_string, \
+			{ __DEVICE_ATTR(_name, S_IRUGO, device_show_string, \
 			NULL), _config }
 
 static CCN_FORMAT_ATTR(node, "config:0-7");
diff --git a/drivers/perf/arm_cspmu/arm_cspmu.h b/drivers/perf/arm_cspmu/arm_cspmu.h
index c4058d602477..93d5b062de8b 100644
--- a/drivers/perf/arm_cspmu/arm_cspmu.h
+++ b/drivers/perf/arm_cspmu/arm_cspmu.h
@@ -23,7 +23,7 @@
 #define ARM_CSPMU_EXT_ATTR(_name, _func, _config)			\
 	(&((struct dev_ext_attribute[]){				\
 		{							\
-			.attr = __ATTR(_name, 0444, _func, NULL),	\
+			.attr = __DEVICE_ATTR(_name, 0444, _func, NULL),\
 			.var = (void *)_config				\
 		}							\
 	})[0].attr.attr)
diff --git a/drivers/perf/arm_dsu_pmu.c b/drivers/perf/arm_dsu_pmu.c
index bcbd19e075a5..8332eaca06dc 100644
--- a/drivers/perf/arm_dsu_pmu.c
+++ b/drivers/perf/arm_dsu_pmu.c
@@ -69,7 +69,7 @@
 #define DSU_EXT_ATTR(_name, _func, _config)		\
 	(&((struct dev_ext_attribute[]) {				\
 		{							\
-			.attr = __ATTR(_name, 0444, _func, NULL),	\
+			.attr = __DEVICE_ATTR(_name, 0444, _func, NULL),\
 			.var = (void *)_config				\
 		}							\
 	})[0].attr.attr)
diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c
index b70f3fedf028..e298d6d6371e 100644
--- a/drivers/perf/arm_spe_pmu.c
+++ b/drivers/perf/arm_spe_pmu.c
@@ -172,9 +172,9 @@ static ssize_t arm_spe_pmu_cap_show_hex(struct device *dev,
 	return sysfs_emit(buf, "0x%llx\n", arm_spe_pmu_cap_get(spe_pmu, cap));
 }
 
-#define SPE_EXT_ATTR_ENTRY(_name, _func, _var)				\
-	&((struct dev_ext_attribute[]) {				\
-		{ __ATTR(_name, S_IRUGO, _func, NULL), (void *)_var }	\
+#define SPE_EXT_ATTR_ENTRY(_name, _func, _var)					\
+	&((struct dev_ext_attribute[]) {					\
+		{ __DEVICE_ATTR(_name, S_IRUGO, _func, NULL), (void *)_var }	\
 	})[0].attr.attr
 
 #define SPE_CAP_EXT_ATTR_ENTRY(_name, _var)				\
diff --git a/drivers/perf/cxl_pmu.c b/drivers/perf/cxl_pmu.c
index 2c8a03cc11e4..a36cf792a2d0 100644
--- a/drivers/perf/cxl_pmu.c
+++ b/drivers/perf/cxl_pmu.c
@@ -216,11 +216,11 @@ static int cxl_pmu_parse_caps(struct device *dev, struct cxl_pmu_info *info)
 }
 
 #define CXL_PMU_FORMAT_ATTR(_name, _format)\
-	(&((struct dev_ext_attribute[]) {					\
-		{								\
-			.attr = __ATTR(_name, 0444, device_show_string, NULL),	\
-			.var = (void *)_format					\
-		}								\
+	(&((struct dev_ext_attribute[]) {						\
+		{									\
+			.attr = __DEVICE_ATTR(_name, 0444, device_show_string, NULL),	\
+			.var = (void *)_format						\
+		}									\
 		})[0].attr.attr)
 
 enum {
diff --git a/drivers/perf/fsl_imx8_ddr_perf.c b/drivers/perf/fsl_imx8_ddr_perf.c
index dd8046265584..7553c5872600 100644
--- a/drivers/perf/fsl_imx8_ddr_perf.c
+++ b/drivers/perf/fsl_imx8_ddr_perf.c
@@ -214,7 +214,7 @@ static ssize_t ddr_perf_filter_cap_show(struct device *dev,
 
 #define PERF_EXT_ATTR_ENTRY(_name, _func, _var)				\
 	(&((struct dev_ext_attribute) {					\
-		__ATTR(_name, 0444, _func, NULL), (void *)_var		\
+		__DEVICE_ATTR(_name, 0444, _func, NULL), (void *)_var	\
 	}).attr.attr)
 
 #define PERF_FILTER_EXT_ATTR_ENTRY(_name, _var)				\
diff --git a/drivers/perf/fujitsu_uncore_pmu.c b/drivers/perf/fujitsu_uncore_pmu.c
index fa64146fcac6..db90e181b9a8 100644
--- a/drivers/perf/fujitsu_uncore_pmu.c
+++ b/drivers/perf/fujitsu_uncore_pmu.c
@@ -291,7 +291,7 @@ static void fujitsu_uncore_event_read(struct perf_event *event)
 
 #define UNCORE_PMU_FORMAT_ATTR(_name, _config)				      \
 	(&((struct dev_ext_attribute[]) {				      \
-		{ .attr = __ATTR(_name, 0444, device_show_string, NULL),      \
+		{ .attr = __DEVICE_ATTR(_name, 0444, device_show_string, NULL), \
 		  .var = (void *)_config, }				      \
 	})[0].attr.attr)
 
diff --git a/drivers/perf/hisilicon/hisi_pcie_pmu.c b/drivers/perf/hisilicon/hisi_pcie_pmu.c
index 0f55d871c67e..0a69d13fa453 100644
--- a/drivers/perf/hisilicon/hisi_pcie_pmu.c
+++ b/drivers/perf/hisilicon/hisi_pcie_pmu.c
@@ -110,7 +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, device_show_string, NULL),       \
+		{ .attr = __DEVICE_ATTR(_name, 0444, device_show_string, NULL),\
 		  .var = (void *)_format }                                     \
 	})[0].attr.attr)
 
diff --git a/drivers/perf/hisilicon/hisi_uncore_pmu.h b/drivers/perf/hisilicon/hisi_uncore_pmu.h
index 3ffe6acda653..a4cb9ed7ea20 100644
--- a/drivers/perf/hisilicon/hisi_uncore_pmu.h
+++ b/drivers/perf/hisilicon/hisi_uncore_pmu.h
@@ -27,9 +27,9 @@
 #define HISI_MAX_COUNTERS	0x18
 #define to_hisi_pmu(p)	(container_of(p, struct hisi_pmu, pmu))
 
-#define HISI_PMU_ATTR(_name, _func, _config)				\
-	(&((struct dev_ext_attribute[]) {				\
-		{ __ATTR(_name, 0444, _func, NULL), (void *)_config }   \
+#define HISI_PMU_ATTR(_name, _func, _config)				     \
+	(&((struct dev_ext_attribute[]) {				     \
+		{ __DEVICE_ATTR(_name, 0444, _func, NULL), (void *)_config } \
 	})[0].attr.attr)
 
 #define HISI_PMU_FORMAT_ATTR(_name, _config)		\
diff --git a/drivers/perf/hisilicon/hns3_pmu.c b/drivers/perf/hisilicon/hns3_pmu.c
index c157f3572cae..88a1129e9b90 100644
--- a/drivers/perf/hisilicon/hns3_pmu.c
+++ b/drivers/perf/hisilicon/hns3_pmu.c
@@ -405,9 +405,9 @@ static ssize_t hns3_pmu_filter_mode_show(struct device *dev,
 	return len;
 }
 
-#define HNS3_PMU_ATTR(_name, _func, _config)				\
-	(&((struct dev_ext_attribute[]) {				\
-		{ __ATTR(_name, 0444, _func, NULL), (void *)_config }	\
+#define HNS3_PMU_ATTR(_name, _func, _config)				     \
+	(&((struct dev_ext_attribute[]) {				     \
+		{ __DEVICE_ATTR(_name, 0444, _func, NULL), (void *)_config } \
 	})[0].attr.attr)
 
 #define HNS3_PMU_FORMAT_ATTR(_name, _format) \
diff --git a/drivers/perf/nvidia_t410_c2c_pmu.c b/drivers/perf/nvidia_t410_c2c_pmu.c
index bff875f4f625..a41d5712da91 100644
--- a/drivers/perf/nvidia_t410_c2c_pmu.c
+++ b/drivers/perf/nvidia_t410_c2c_pmu.c
@@ -545,7 +545,7 @@ static struct attribute_group nv_c2c_pmu_peer_attr_group = {
 #define NV_C2C_PMU_EXT_ATTR(_name, _func, _config)			\
 	(&((struct dev_ext_attribute[]){				\
 		{							\
-			.attr = __ATTR(_name, 0444, _func, NULL),	\
+			.attr = __DEVICE_ATTR(_name, 0444, _func, NULL),\
 			.var = (void *)_config				\
 		}							\
 	})[0].attr.attr)
diff --git a/drivers/perf/nvidia_t410_cmem_latency_pmu.c b/drivers/perf/nvidia_t410_cmem_latency_pmu.c
index 6c8e41598ec1..da91a51fe29e 100644
--- a/drivers/perf/nvidia_t410_cmem_latency_pmu.c
+++ b/drivers/perf/nvidia_t410_cmem_latency_pmu.c
@@ -435,12 +435,12 @@ static struct attribute_group cmem_lat_pmu_identifier_attr_group = {
 
 /* Format attributes. */
 
-#define NV_PMU_EXT_ATTR(_name, _func, _config)			\
-	(&((struct dev_ext_attribute[]){				\
-		{							\
-			.attr = __ATTR(_name, 0444, _func, NULL),	\
-			.var = (void *)_config				\
-		}							\
+#define NV_PMU_EXT_ATTR(_name, _func, _config)					\
+	(&((struct dev_ext_attribute[]){					\
+		{								\
+			.attr = __DEVICE_ATTR(_name, 0444, _func, NULL),	\
+			.var = (void *)_config					\
+		}								\
 	})[0].attr.attr)
 
 static struct attribute *cmem_lat_pmu_formats[] = {
diff --git a/drivers/perf/qcom_l3_pmu.c b/drivers/perf/qcom_l3_pmu.c
index e18d0f94e8d8..d036fa05aeab 100644
--- a/drivers/perf/qcom_l3_pmu.c
+++ b/drivers/perf/qcom_l3_pmu.c
@@ -609,10 +609,10 @@ static void qcom_l3_cache__event_read(struct perf_event *event)
 
 /* formats */
 
-#define L3CACHE_PMU_FORMAT_ATTR(_name, _config)				      \
-	(&((struct dev_ext_attribute[]) {				      \
-		{ .attr = __ATTR(_name, 0444, device_show_string, NULL),      \
-		  .var = (void *) _config, }				      \
+#define L3CACHE_PMU_FORMAT_ATTR(_name, _config)				        \
+	(&((struct dev_ext_attribute[]) {				        \
+		{ .attr = __DEVICE_ATTR(_name, 0444, device_show_string, NULL), \
+		  .var = (void *) _config, }				        \
 	})[0].attr.attr)
 
 static struct attribute *qcom_l3_cache_pmu_formats[] = {
diff --git a/drivers/perf/starfive_starlink_pmu.c b/drivers/perf/starfive_starlink_pmu.c
index 98e5ccee2fdc..d9843645554b 100644
--- a/drivers/perf/starfive_starlink_pmu.c
+++ b/drivers/perf/starfive_starlink_pmu.c
@@ -51,7 +51,7 @@
 
 #define STARLINK_FORMAT_ATTR(_name, _config)				      \
 	(&((struct dev_ext_attribute[]) {				      \
-		{ .attr = __ATTR(_name, 0444, starlink_pmu_sysfs_format_show, NULL), \
+		{ .attr = __DEVICE_ATTR(_name, 0444, starlink_pmu_sysfs_format_show, NULL), \
 		  .var = (void *)_config, }				      \
 	})[0].attr.attr)
 
diff --git a/drivers/perf/xgene_pmu.c b/drivers/perf/xgene_pmu.c
index ab3623fab914..104cd0277b58 100644
--- a/drivers/perf/xgene_pmu.c
+++ b/drivers/perf/xgene_pmu.c
@@ -164,7 +164,7 @@ enum xgene_pmu_dev_type {
  */
 #define XGENE_PMU_FORMAT_ATTR(_name, _config)		\
 	(&((struct dev_ext_attribute[]) {		\
-		{ .attr = __ATTR(_name, S_IRUGO, device_show_string, NULL), \
+		{ .attr = __DEVICE_ATTR(_name, S_IRUGO, device_show_string, NULL), \
 		  .var = (void *) _config, }		\
 	})[0].attr.attr)
 

-- 
2.55.0

[PATCH v2 3/3] driver core: Constify the signature of device_show/store_*()

[Thomas Weißschuh]

Prepare for the constification of 'struct dev_ext_attribute' by changing
the signature of the standard callback functions.

Migrate the hv-24x7 driver in the same commit. It is the only user to
manually assign one of the standard callbacks.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 arch/powerpc/perf/hv-24x7.c |  2 +-
 drivers/base/core.c         | 30 +++++++++++++++---------------
 include/linux/device.h      | 14 +++++++-------
 3 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c
index b0eedf185960..3e094dc7d76b 100644
--- a/arch/powerpc/perf/hv-24x7.c
+++ b/arch/powerpc/perf/hv-24x7.c
@@ -462,7 +462,7 @@ static struct attribute *device_str_attr_create_(char *name, char *str)
 	attr->var = str;
 	attr->attr.attr.name = name;
 	attr->attr.attr.mode = 0444;
-	attr->attr.show = device_show_string;
+	attr->attr.show_const = device_show_string;
 
 	return &attr->attr.attr;
 }
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 4c0c373998a1..5daa88fa724a 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -2517,13 +2517,13 @@ static const struct sysfs_ops dev_sysfs_ops = {
 	.store	= dev_attr_store,
 };
 
-#define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
+#define to_ext_attr(x) container_of_const(x, struct dev_ext_attribute, attr)
 
 ssize_t device_store_ulong(struct device *dev,
-			   struct device_attribute *attr,
+			   const struct device_attribute *attr,
 			   const char *buf, size_t size)
 {
-	struct dev_ext_attribute *ea = to_ext_attr(attr);
+	const struct dev_ext_attribute *ea = to_ext_attr(attr);
 	int ret;
 	unsigned long new;
 
@@ -2537,19 +2537,19 @@ ssize_t device_store_ulong(struct device *dev,
 EXPORT_SYMBOL_GPL(device_store_ulong);
 
 ssize_t device_show_ulong(struct device *dev,
-			  struct device_attribute *attr,
+			  const struct device_attribute *attr,
 			  char *buf)
 {
-	struct dev_ext_attribute *ea = to_ext_attr(attr);
+	const struct dev_ext_attribute *ea = to_ext_attr(attr);
 	return sysfs_emit(buf, "%lx\n", *(unsigned long *)(ea->var));
 }
 EXPORT_SYMBOL_GPL(device_show_ulong);
 
 ssize_t device_store_int(struct device *dev,
-			 struct device_attribute *attr,
+			 const struct device_attribute *attr,
 			 const char *buf, size_t size)
 {
-	struct dev_ext_attribute *ea = to_ext_attr(attr);
+	const struct dev_ext_attribute *ea = to_ext_attr(attr);
 	int ret;
 	long new;
 
@@ -2566,19 +2566,19 @@ ssize_t device_store_int(struct device *dev,
 EXPORT_SYMBOL_GPL(device_store_int);
 
 ssize_t device_show_int(struct device *dev,
-			struct device_attribute *attr,
+			const struct device_attribute *attr,
 			char *buf)
 {
-	struct dev_ext_attribute *ea = to_ext_attr(attr);
+	const struct dev_ext_attribute *ea = to_ext_attr(attr);
 
 	return sysfs_emit(buf, "%d\n", *(int *)(ea->var));
 }
 EXPORT_SYMBOL_GPL(device_show_int);
 
-ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
+ssize_t device_store_bool(struct device *dev, const struct device_attribute *attr,
 			  const char *buf, size_t size)
 {
-	struct dev_ext_attribute *ea = to_ext_attr(attr);
+	const struct dev_ext_attribute *ea = to_ext_attr(attr);
 
 	if (kstrtobool(buf, ea->var) < 0)
 		return -EINVAL;
@@ -2587,19 +2587,19 @@ ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
 }
 EXPORT_SYMBOL_GPL(device_store_bool);
 
-ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
+ssize_t device_show_bool(struct device *dev, const struct device_attribute *attr,
 			 char *buf)
 {
-	struct dev_ext_attribute *ea = to_ext_attr(attr);
+	const struct dev_ext_attribute *ea = to_ext_attr(attr);
 
 	return sysfs_emit(buf, "%d\n", *(bool *)(ea->var));
 }
 EXPORT_SYMBOL_GPL(device_show_bool);
 
 ssize_t device_show_string(struct device *dev,
-			   struct device_attribute *attr, char *buf)
+			   const struct device_attribute *attr, char *buf)
 {
-	struct dev_ext_attribute *ea = to_ext_attr(attr);
+	const struct dev_ext_attribute *ea = to_ext_attr(attr);
 
 	return sysfs_emit(buf, "%s\n", (char *)ea->var);
 }
diff --git a/include/linux/device.h b/include/linux/device.h
index aee79fd6b32b..90cdd77458bb 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -129,19 +129,19 @@ struct dev_ext_attribute {
 	void *var;
 };
 
-ssize_t device_show_ulong(struct device *dev, struct device_attribute *attr,
+ssize_t device_show_ulong(struct device *dev, const struct device_attribute *attr,
 			  char *buf);
-ssize_t device_store_ulong(struct device *dev, struct device_attribute *attr,
+ssize_t device_store_ulong(struct device *dev, const struct device_attribute *attr,
 			   const char *buf, size_t count);
-ssize_t device_show_int(struct device *dev, struct device_attribute *attr,
+ssize_t device_show_int(struct device *dev, const struct device_attribute *attr,
 			char *buf);
-ssize_t device_store_int(struct device *dev, struct device_attribute *attr,
+ssize_t device_store_int(struct device *dev, const struct device_attribute *attr,
 			 const char *buf, size_t count);
-ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
+ssize_t device_show_bool(struct device *dev, const struct device_attribute *attr,
 			char *buf);
-ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
+ssize_t device_store_bool(struct device *dev, const struct device_attribute *attr,
 			 const char *buf, size_t count);
-ssize_t device_show_string(struct device *dev, struct device_attribute *attr,
+ssize_t device_show_string(struct device *dev, const struct device_attribute *attr,
 			   char *buf);
 
 typedef ssize_t __device_show_handler_const(struct device *dev, const struct device_attribute *attr,

-- 
2.55.0

Re: [PATCH v2 2/3] drivers: perf: Use __DEVICE_ATTR() macro to initialize dev_ext_attribute

[sashiko-bot]

> The upcoming constification of the device_show_*() callback
> signatures requires the users to handle the transition automatically.
> 
> Switch to the __DEVICE_ATTR() macro which can do this.
> 
> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260907-sysfs-const-attr-dev_ext_attr-v2-0-bf53afe57071@weissschuh.net?part=2

Re: [PATCH v2 3/3] driver core: Constify the signature of device_show/store_*()

[sashiko-bot]

> Prepare for the constification of 'struct dev_ext_attribute' by changing
> the signature of the standard callback functions.
> 
> Migrate the hv-24x7 driver in the same commit. It is the only user to
> manually assign one of the standard callbacks.
> 
> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260907-sysfs-const-attr-dev_ext_attr-v2-0-bf53afe57071@weissschuh.net?part=3

Re: [PATCH v2 1/3] x86/mce: Use __DEVICE_ATTR() macro to initialize dev_ext_attribute

[sashiko-bot]

> The upcoming constification of the device_show_int() and
> device_show_bool() signatures requires the users to handle the
> transition automatically.
> 
> Switch to the __DEVICE_ATTR() macro which can do this.
> 
> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260907-sysfs-const-attr-dev_ext_attr-v2-0-bf53afe57071@weissschuh.net?part=1

Re: [PATCH v2 2/3] drivers: perf: Use __DEVICE_ATTR() macro to initialize dev_ext_attribute

[Jonathan Cameron]

On Mon, 07 Sep 2026 07:45:02 +0200
Thomas Weißschuh <linux@weissschuh.net> wrote:

> The upcoming constification of the device_show_*() callback
> signatures requires the users to handle the transition automatically.
> 
> Switch to the __DEVICE_ATTR() macro which can do this.
> 
> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

Acked-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com> #for cxl_pmu