Re: [PATCH v24 02/10] drivers/base: refactor memory.c to use .is_visible()
From: Eric DeVolder
Date: Thu Jun 29 2023 - 09:26:15 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 memory.c.
static struct attribute *memory_memblk_attrs[] = {
&dev_attr_phys_index.attr,
&dev_attr_state.attr,
&dev_attr_phys_device.attr,
&dev_attr_removable.attr,
#ifdef CONFIG_MEMORY_HOTREMOVE
&dev_attr_valid_zones.attr,
#endif
NULL
};
and
static struct attribute *memory_root_attrs[] = {
#ifdef CONFIG_ARCH_MEMORY_PROBE
&dev_attr_probe.attr,
#endif
#ifdef CONFIG_MEMORY_FAILURE
&dev_attr_soft_offline_page.attr,
&dev_attr_hard_offline_page.attr,
#endif
&dev_attr_block_size_bytes.attr,
&dev_attr_auto_online_blocks.attr,
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_xx() attributes are moved outside of #ifdefs, so that
those structs are always present for the memory_memblk_attrs[] and
memory_root_attrs[].
- the #ifdefs guarding the attributes in the memory_memblk_attrs[] and
memory_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/memory.c | 78 +++++++++++++++++++++++++++++++++++--------
1 file changed, 65 insertions(+), 13 deletions(-)
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index b456ac213610..f03eda7e1c9c 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -405,10 +405,12 @@ static int print_allowed_zone(char *buf, int len, int nid,
return sysfs_emit_at(buf, len, " %s", zone->name);
}
+#endif
static ssize_t valid_zones_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
+#ifdef CONFIG_MEMORY_HOTREMOVE
struct memory_block *mem = to_memory_block(dev);
unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
@@ -444,9 +446,11 @@ static ssize_t valid_zones_show(struct device *dev,
out:
len += sysfs_emit_at(buf, len, "\n");
return len;
+#else
+ return 0;
+#endif
}
static DEVICE_ATTR_RO(valid_zones);
-#endif
static DEVICE_ATTR_RO(phys_index);
static DEVICE_ATTR_RW(state);
@@ -496,10 +500,10 @@ static DEVICE_ATTR_RW(auto_online_blocks);
* as well as ppc64 will do all of their discovery in userspace
* and will require this interface.
*/
-#ifdef CONFIG_ARCH_MEMORY_PROBE
static ssize_t probe_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
+#ifdef CONFIG_ARCH_MEMORY_PROBE
u64 phys_addr;
int nid, ret;
unsigned long pages_per_block = PAGES_PER_SECTION * sections_per_block;
@@ -527,12 +531,13 @@ static ssize_t probe_store(struct device *dev, struct device_attribute *attr,
out:
unlock_device_hotplug();
return ret;
+#else
+ return 0;
+#endif
}
static DEVICE_ATTR_WO(probe);
-#endif
-#ifdef CONFIG_MEMORY_FAILURE
/*
* Support for offlining pages of memory
*/
@@ -542,6 +547,7 @@ static ssize_t soft_offline_page_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
+#ifdef CONFIG_MEMORY_FAILURE
int ret;
u64 pfn;
if (!capable(CAP_SYS_ADMIN))
@@ -551,6 +557,9 @@ static ssize_t soft_offline_page_store(struct device *dev,
pfn >>= PAGE_SHIFT;
ret = soft_offline_page(pfn, 0);
return ret == 0 ? count : ret;
+#else
+ return 0;
+#endif
}
/* Forcibly offline a page, including killing processes. */
@@ -558,6 +567,7 @@ static ssize_t hard_offline_page_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
+#ifdef CONFIG_MEMORY_FAILURE
int ret;
u64 pfn;
if (!capable(CAP_SYS_ADMIN))
@@ -569,11 +579,13 @@ static ssize_t hard_offline_page_store(struct device *dev,
if (ret == -EOPNOTSUPP)
ret = 0;
return ret ? ret : count;
+#else
+ return 0;
+#endif
}
static DEVICE_ATTR_WO(soft_offline_page);
static DEVICE_ATTR_WO(hard_offline_page);
-#endif
/* See phys_device_show(). */
int __weak arch_get_memory_phys_device(unsigned long start_pfn)
@@ -611,14 +623,35 @@ static struct attribute *memory_memblk_attrs[] = {
&dev_attr_state.attr,
&dev_attr_phys_device.attr,
&dev_attr_removable.attr,
-#ifdef CONFIG_MEMORY_HOTREMOVE
&dev_attr_valid_zones.attr,
-#endif
NULL
};
+static umode_t
+memory_memblk_attr_is_visible(struct kobject *kobj,
+ struct attribute *attr, int unused)
+{
+ umode_t mode = attr->mode;
+
+ if (attr == &dev_attr_phys_index.attr)
+ return mode;
+ if (attr == &dev_attr_state.attr)
+ return mode;
+ if (attr == &dev_attr_phys_device.attr)
+ return mode;
+ if (attr == &dev_attr_removable.attr)
+ return mode;
+ if (IS_ENABLED(CONFIG_MEMORY_HOTREMOVE)) {
+ if (attr == &dev_attr_valid_zones.attr)
+ return mode;
+ }
+
+ return 0;
+}
+
static const struct attribute_group memory_memblk_attr_group = {
.attrs = memory_memblk_attrs,
+ .is_visible = memory_memblk_attr_is_visible,
};
static const struct attribute_group *memory_memblk_attr_groups[] = {
@@ -878,22 +911,41 @@ void remove_memory_block_devices(unsigned long start, unsigned long size)
}
static struct attribute *memory_root_attrs[] = {
-#ifdef CONFIG_ARCH_MEMORY_PROBE
&dev_attr_probe.attr,
-#endif
-
-#ifdef CONFIG_MEMORY_FAILURE
&dev_attr_soft_offline_page.attr,
&dev_attr_hard_offline_page.attr,
-#endif
-
&dev_attr_block_size_bytes.attr,
&dev_attr_auto_online_blocks.attr,
NULL
};
+static umode_t
+memory_root_attr_is_visible(struct kobject *kobj,
+ struct attribute *attr, int unused)
+{
+ umode_t mode = attr->mode;
+
+ if (IS_ENABLED(CONFIG_ARCH_MEMORY_PROBE)) {
+ if (attr == &dev_attr_probe.attr)
+ return mode;
+ }
+ if (IS_ENABLED(CONFIG_MEMORY_FAILURE)) {
+ if (attr == &dev_attr_soft_offline_page.attr)
+ return mode;
+ if (attr == &dev_attr_hard_offline_page.attr)
+ return mode;
+ }
+ if (attr == &dev_attr_block_size_bytes.attr)
+ return mode;
+ if (attr == &dev_attr_auto_online_blocks.attr)
+ return mode;
+
+ return 0;
+}
+
static const struct attribute_group memory_root_attr_group = {
.attrs = memory_root_attrs,
+ .is_visible = memory_root_attr_is_visible,
};
static const struct attribute_group *memory_root_attr_groups[] = {