Re: [PATCH v24 01/10] drivers/base: refactor cpu.c to use .is_visible()
From: Eric DeVolder
Date: Thu Jun 29 2023 - 09:27:04 EST
I still need to convert the ifdefs within the functions to IS_ENABLED(), my apologies.
eric
On 6/28/23 13:52, Eric DeVolder wrote:
Greg Kroah-Hartman requested that this file use the .is_visible()
method instead of #ifdefs for the attributes in cpu.c.
static struct attribute *cpu_root_attrs[] = {
#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
&dev_attr_probe.attr,
&dev_attr_release.attr,
#endif
&cpu_attrs[0].attr.attr,
&cpu_attrs[1].attr.attr,
&cpu_attrs[2].attr.attr,
&dev_attr_kernel_max.attr,
&dev_attr_offline.attr,
&dev_attr_isolated.attr,
#ifdef CONFIG_NO_HZ_FULL
&dev_attr_nohz_full.attr,
#endif
#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
&dev_attr_modalias.attr,
#endif
NULL
};
To that end:
- the .is_visible() method is implemented, and IS_ENABLED(), rather
than #ifdef, is used to determine the visibility of the attribute.
- the DEVICE_ATTR() attributes are moved outside of #ifdefs, so that
those structs are always present for the cpu_root_attrs[].
- the #ifdefs guarding the attributes in the cpu_root_attrs[] are moved
to the corresponding callback function; as the callback function must
exist now that the attribute is always compiled-in (though not
necessarily visible).
No functionality change intended.
Signed-off-by: Eric DeVolder <eric.devolder@xxxxxxxxxx>
---
drivers/base/cpu.c | 67 ++++++++++++++++++++++++++++++++++++----------
1 file changed, 53 insertions(+), 14 deletions(-)
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index c1815b9dae68..75fa46a567a1 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -82,13 +82,14 @@ void unregister_cpu(struct cpu *cpu)
per_cpu(cpu_sys_devices, logical_cpu) = NULL;
return;
}
+#endif /* CONFIG_HOTPLUG_CPU */
-#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
static ssize_t cpu_probe_store(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t count)
{
+#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
ssize_t cnt;
int ret;
@@ -100,6 +101,9 @@ static ssize_t cpu_probe_store(struct device *dev,
unlock_device_hotplug();
return cnt;
+#else
+ return 0;
+#endif
}
static ssize_t cpu_release_store(struct device *dev,
@@ -107,6 +111,7 @@ static ssize_t cpu_release_store(struct device *dev,
const char *buf,
size_t count)
{
+#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
ssize_t cnt;
int ret;
@@ -118,12 +123,13 @@ static ssize_t cpu_release_store(struct device *dev,
unlock_device_hotplug();
return cnt;
+#else
+ return 0;
+#endif
}
static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
static DEVICE_ATTR(release, S_IWUSR, NULL, cpu_release_store);
-#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
-#endif /* CONFIG_HOTPLUG_CPU */
#ifdef CONFIG_KEXEC
#include <linux/kexec.h>
@@ -273,14 +279,16 @@ static ssize_t print_cpus_isolated(struct device *dev,
}
static DEVICE_ATTR(isolated, 0444, print_cpus_isolated, NULL);
-#ifdef CONFIG_NO_HZ_FULL
static ssize_t print_cpus_nohz_full(struct device *dev,
struct device_attribute *attr, char *buf)
{
+#ifdef CONFIG_NO_HZ_FULL
return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(tick_nohz_full_mask));
+#else
+ return 0;
+#endif
}
static DEVICE_ATTR(nohz_full, 0444, print_cpus_nohz_full, NULL);
-#endif
static void cpu_device_release(struct device *dev)
{
@@ -301,12 +309,12 @@ static void cpu_device_release(struct device *dev)
*/
}
-#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
static ssize_t print_cpu_modalias(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int len = 0;
+#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
u32 i;
len += sysfs_emit_at(buf, len,
@@ -322,9 +330,11 @@ static ssize_t print_cpu_modalias(struct device *dev,
len += sysfs_emit_at(buf, len, ",%04X", i);
}
len += sysfs_emit_at(buf, len, "\n");
+#endif
return len;
}
+#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
static int cpu_uevent(const struct device *dev, struct kobj_uevent_env *env)
{
char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
@@ -451,32 +461,61 @@ struct device *cpu_device_create(struct device *parent, void *drvdata,
}
EXPORT_SYMBOL_GPL(cpu_device_create);
-#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
static DEVICE_ATTR(modalias, 0444, print_cpu_modalias, NULL);
-#endif
static struct attribute *cpu_root_attrs[] = {
-#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
&dev_attr_probe.attr,
&dev_attr_release.attr,
-#endif
&cpu_attrs[0].attr.attr,
&cpu_attrs[1].attr.attr,
&cpu_attrs[2].attr.attr,
&dev_attr_kernel_max.attr,
&dev_attr_offline.attr,
&dev_attr_isolated.attr,
-#ifdef CONFIG_NO_HZ_FULL
&dev_attr_nohz_full.attr,
-#endif
-#ifdef CONFIG_GENERIC_CPU_AUTOPROBE
&dev_attr_modalias.attr,
-#endif
NULL
};
+static umode_t
+cpu_root_attr_is_visible(struct kobject *kobj,
+ struct attribute *attr, int unused)
+{
+ umode_t mode = attr->mode;
+
+ if (IS_ENABLED(CONFIG_ARCH_CPU_PROBE_RELEASE)) {
+ if (attr == &dev_attr_probe.attr)
+ return mode;
+ if (attr == &dev_attr_release.attr)
+ return mode;
+ }
+ if (attr == &cpu_attrs[0].attr.attr)
+ return mode;
+ if (attr == &cpu_attrs[1].attr.attr)
+ return mode;
+ if (attr == &cpu_attrs[2].attr.attr)
+ return mode;
+ if (attr == &dev_attr_kernel_max.attr)
+ return mode;
+ if (attr == &dev_attr_offline.attr)
+ return mode;
+ if (attr == &dev_attr_isolated.attr)
+ return mode;
+ if (IS_ENABLED(CONFIG_NO_HZ_FULL)) {
+ if (attr == &dev_attr_nohz_full.attr)
+ return mode;
+ }
+ if (IS_ENABLED(CONFIG_GENERIC_CPU_AUTOPROBE)) {
+ if (attr == &dev_attr_modalias.attr)
+ return mode;
+ }
+
+ return 0;
+}
+
static const struct attribute_group cpu_root_attr_group = {
.attrs = cpu_root_attrs,
+ .is_visible = cpu_root_attr_is_visible,
};
static const struct attribute_group *cpu_root_attr_groups[] = {