From 66bc1a173328dec3e37c203a999f2a2914c96b56 Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Sat, 6 Apr 2024 15:52:02 +0200 Subject: treewide: Use sysfs_bin_attr_simple_read() helper Deduplicate ->read() callbacks of bin_attributes which are backed by a simple buffer in memory: Use the newly introduced sysfs_bin_attr_simple_read() helper instead, either by referencing it directly or by declaring such bin_attributes with BIN_ATTR_SIMPLE_RO() or BIN_ATTR_SIMPLE_ADMIN_RO(). Aside from a reduction of LoC, this shaves off a few bytes from vmlinux (304 bytes on an x86_64 allyesconfig). No functional change intended. Signed-off-by: Lukas Wunner Acked-by: Zhi Wang Acked-by: Michael Ellerman Acked-by: Rafael J. Wysocki Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/92ee0a0e83a5a3f3474845db6c8575297698933a.1712410202.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/platforms/powernv/opal.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) (limited to 'arch/powerpc') diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c index 45dd77e3ccf6..5d0f35bb917e 100644 --- a/arch/powerpc/platforms/powernv/opal.c +++ b/arch/powerpc/platforms/powernv/opal.c @@ -792,14 +792,6 @@ static int __init opal_sysfs_init(void) return 0; } -static ssize_t export_attr_read(struct file *fp, struct kobject *kobj, - struct bin_attribute *bin_attr, char *buf, - loff_t off, size_t count) -{ - return memory_read_from_buffer(buf, count, &off, bin_attr->private, - bin_attr->size); -} - static int opal_add_one_export(struct kobject *parent, const char *export_name, struct device_node *np, const char *prop_name) { @@ -826,7 +818,7 @@ static int opal_add_one_export(struct kobject *parent, const char *export_name, sysfs_bin_attr_init(attr); attr->attr.name = name; attr->attr.mode = 0400; - attr->read = export_attr_read; + attr->read = sysfs_bin_attr_simple_read; attr->private = __va(vals[0]); attr->size = vals[1]; -- cgit v1.2.3-70-g09d2 From 3cc50d07be10f67aff836f8247a240ec132c6a67 Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Sat, 20 Apr 2024 22:00:01 +0200 Subject: driver core: Add device_show_string() helper for sysfs attributes For drivers wishing to expose an unsigned long, int or bool at a static memory location in sysfs, the driver core provides ready-made helpers such as device_show_ulong() to be used as ->show() callback. Some drivers need to expose a string and so far they all provide their own ->show() implementation. arch/powerpc/perf/hv-24x7.c went so far as to create a device_show_string() helper but kept it private. Make it public for reuse by other drivers. The pattern seems to be sufficiently frequent to merit a public helper. Add a DEVICE_STRING_ATTR_RO() macro in line with the existing DEVICE_ULONG_ATTR() and similar macros to ease declaration of string attributes. Signed-off-by: Lukas Wunner Acked-by: Michael Ellerman Link: https://lore.kernel.org/r/2e3eaaf2600bb55c0415c23ba301e809403a7aa2.1713608122.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/perf/hv-24x7.c | 10 ---------- drivers/base/core.c | 9 +++++++++ include/linux/device.h | 15 +++++++++++++++ 3 files changed, 24 insertions(+), 10 deletions(-) (limited to 'arch/powerpc') diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c index 057ec2e3451d..d400fa391c27 100644 --- a/arch/powerpc/perf/hv-24x7.c +++ b/arch/powerpc/perf/hv-24x7.c @@ -425,16 +425,6 @@ static char *memdup_to_str(char *maybe_str, int max_len, gfp_t gfp) return kasprintf(gfp, "%.*s", max_len, maybe_str); } -static ssize_t device_show_string(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct dev_ext_attribute *d; - - d = container_of(attr, struct dev_ext_attribute, attr); - - return sprintf(buf, "%s\n", (char *)d->var); -} - static ssize_t cpumask_show(struct device *dev, struct device_attribute *attr, char *buf) { diff --git a/drivers/base/core.c b/drivers/base/core.c index 4d51928c4088..131d96c6090b 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -2538,6 +2538,15 @@ ssize_t device_show_bool(struct device *dev, struct device_attribute *attr, } EXPORT_SYMBOL_GPL(device_show_bool); +ssize_t device_show_string(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dev_ext_attribute *ea = to_ext_attr(attr); + + return sysfs_emit(buf, "%s\n", (char *)ea->var); +} +EXPORT_SYMBOL_GPL(device_show_string); + /** * device_release - free device structure. * @kobj: device's kobject. diff --git a/include/linux/device.h b/include/linux/device.h index 07f4d2af1e3c..b6b6ff881a3f 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -132,6 +132,8 @@ ssize_t device_show_bool(struct device *dev, struct device_attribute *attr, char *buf); ssize_t device_store_bool(struct device *dev, struct device_attribute *attr, const char *buf, size_t count); +ssize_t device_show_string(struct device *dev, struct device_attribute *attr, + char *buf); /** * DEVICE_ATTR - Define a device attribute. @@ -251,6 +253,19 @@ ssize_t device_store_bool(struct device *dev, struct device_attribute *attr, struct dev_ext_attribute dev_attr_##_name = \ { __ATTR(_name, _mode, device_show_bool, device_store_bool), &(_var) } +/** + * DEVICE_STRING_ATTR_RO - Define a device attribute backed by a r/o string. + * @_name: Attribute name. + * @_mode: File mode. + * @_var: Identifier of string. + * + * Like DEVICE_ULONG_ATTR(), but @_var is a string. Because the length of the + * string allocation is unknown, the attribute must be read-only. + */ +#define DEVICE_STRING_ATTR_RO(_name, _mode, _var) \ + struct dev_ext_attribute dev_attr_##_name = \ + { __ATTR(_name, (_mode) & ~0222, device_show_string, NULL), (_var) } + #define DEVICE_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \ struct device_attribute dev_attr_##_name = \ __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) -- cgit v1.2.3-70-g09d2