2023-06-28 18:57:30

by Eric DeVolder

[permalink] [raw]
Subject: [PATCH v24 01/10] drivers/base: refactor cpu.c to use .is_visible()

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 <[email protected]>
---
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[] = {
--
2.31.1



2023-06-29 13:47:53

by Eric DeVolder

[permalink] [raw]
Subject: Re: [PATCH v24 01/10] drivers/base: refactor cpu.c to use .is_visible()

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 <[email protected]>
> ---
> 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[] = {