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 function body of the callback functions are now wrapped with
   IS_ENABLED(); 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/memory.c | 229 ++++++++++++++++++++++++++----------------
 1 file changed, 140 insertions(+), 89 deletions(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index b456ac213610..7294112fe646 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -391,62 +391,66 @@ static ssize_t phys_device_show(struct device *dev,
                          arch_get_memory_phys_device(start_pfn));
 }
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
 static int print_allowed_zone(char *buf, int len, int nid,
                              struct memory_group *group,
                              unsigned long start_pfn, unsigned long nr_pages,
                              int online_type, struct zone *default_zone)
 {
-       struct zone *zone;
+       if (IS_ENABLED(CONFIG_MEMORY_HOTREMOVE)) {
+               struct zone *zone;
 
-       zone = zone_for_pfn_range(online_type, nid, group, start_pfn, nr_pages);
-       if (zone == default_zone)
-               return 0;
+               zone = zone_for_pfn_range(online_type, nid, group, start_pfn, 
nr_pages);
+               if (zone == default_zone)
+                       return 0;
 
-       return sysfs_emit_at(buf, len, " %s", zone->name);
+               return sysfs_emit_at(buf, len, " %s", zone->name);
+       }
+       return 0;
 }
 
 static ssize_t valid_zones_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
 {
-       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;
-       struct memory_group *group = mem->group;
-       struct zone *default_zone;
-       int nid = mem->nid;
-       int len = 0;
+       if (IS_ENABLED(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;
+               struct memory_group *group = mem->group;
+               struct zone *default_zone;
+               int nid = mem->nid;
+               int len = 0;
 
-       /*
-        * Check the existing zone. Make sure that we do that only on the
-        * online nodes otherwise the page_zone is not reliable
-        */
-       if (mem->state == MEM_ONLINE) {
                /*
-                * If !mem->zone, the memory block spans multiple zones and
-                * cannot get offlined.
-                */
-               default_zone = mem->zone;
-               if (!default_zone)
-                       return sysfs_emit(buf, "%s\n", "none");
-               len += sysfs_emit_at(buf, len, "%s", default_zone->name);
-               goto out;
-       }
+               * Check the existing zone. Make sure that we do that only on the
+               * online nodes otherwise the page_zone is not reliable
+               */
+               if (mem->state == MEM_ONLINE) {
+                       /*
+                        * If !mem->zone, the memory block spans multiple zones 
and
+                        * cannot get offlined.
+                        */
+                       default_zone = mem->zone;
+                       if (!default_zone)
+                               return sysfs_emit(buf, "%s\n", "none");
+                       len += sysfs_emit_at(buf, len, "%s", 
default_zone->name);
+                       goto out;
+               }
 
-       default_zone = zone_for_pfn_range(MMOP_ONLINE, nid, group,
-                                         start_pfn, nr_pages);
+               default_zone = zone_for_pfn_range(MMOP_ONLINE, nid, group,
+                                                 start_pfn, nr_pages);
 
-       len += sysfs_emit_at(buf, len, "%s", default_zone->name);
-       len += print_allowed_zone(buf, len, nid, group, start_pfn, nr_pages,
-                                 MMOP_ONLINE_KERNEL, default_zone);
-       len += print_allowed_zone(buf, len, nid, group, start_pfn, nr_pages,
-                                 MMOP_ONLINE_MOVABLE, default_zone);
+               len += sysfs_emit_at(buf, len, "%s", default_zone->name);
+               len += print_allowed_zone(buf, len, nid, group, start_pfn, 
nr_pages,
+                                         MMOP_ONLINE_KERNEL, default_zone);
+               len += print_allowed_zone(buf, len, nid, group, start_pfn, 
nr_pages,
+                                         MMOP_ONLINE_MOVABLE, default_zone);
 out:
-       len += sysfs_emit_at(buf, len, "\n");
-       return len;
+               len += sysfs_emit_at(buf, len, "\n");
+               return len;
+       }
+       return 0;
 }
 static DEVICE_ATTR_RO(valid_zones);
-#endif
 
 static DEVICE_ATTR_RO(phys_index);
 static DEVICE_ATTR_RW(state);
@@ -496,43 +500,43 @@ 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)
 {
-       u64 phys_addr;
-       int nid, ret;
-       unsigned long pages_per_block = PAGES_PER_SECTION * sections_per_block;
+       if (IS_ENABLED(CONFIG_ARCH_MEMORY_PROBE)) {
+               u64 phys_addr;
+               int nid, ret;
+               unsigned long pages_per_block = PAGES_PER_SECTION * 
sections_per_block;
 
-       ret = kstrtoull(buf, 0, &phys_addr);
-       if (ret)
-               return ret;
+               ret = kstrtoull(buf, 0, &phys_addr);
+               if (ret)
+                       return ret;
 
-       if (phys_addr & ((pages_per_block << PAGE_SHIFT) - 1))
-               return -EINVAL;
+               if (phys_addr & ((pages_per_block << PAGE_SHIFT) - 1))
+                       return -EINVAL;
 
-       ret = lock_device_hotplug_sysfs();
-       if (ret)
-               return ret;
+               ret = lock_device_hotplug_sysfs();
+               if (ret)
+                       return ret;
 
-       nid = memory_add_physaddr_to_nid(phys_addr);
-       ret = __add_memory(nid, phys_addr,
-                          MIN_MEMORY_BLOCK_SIZE * sections_per_block,
-                          MHP_NONE);
+               nid = memory_add_physaddr_to_nid(phys_addr);
+               ret = __add_memory(nid, phys_addr,
+                                  MIN_MEMORY_BLOCK_SIZE * sections_per_block,
+                                  MHP_NONE);
 
-       if (ret)
-               goto out;
+               if (ret)
+                       goto out;
 
-       ret = count;
+               ret = count;
 out:
-       unlock_device_hotplug();
-       return ret;
+               unlock_device_hotplug();
+               return ret;
+       }
+       return 0;
 }
 
 static DEVICE_ATTR_WO(probe);
-#endif
 
-#ifdef CONFIG_MEMORY_FAILURE
 /*
  * Support for offlining pages of memory
  */
@@ -542,15 +546,19 @@ static ssize_t soft_offline_page_store(struct device *dev,
                                       struct device_attribute *attr,
                                       const char *buf, size_t count)
 {
-       int ret;
-       u64 pfn;
-       if (!capable(CAP_SYS_ADMIN))
-               return -EPERM;
-       if (kstrtoull(buf, 0, &pfn) < 0)
-               return -EINVAL;
-       pfn >>= PAGE_SHIFT;
-       ret = soft_offline_page(pfn, 0);
-       return ret == 0 ? count : ret;
+       if (IS_ENABLED(CONFIG_MEMORY_FAILURE)) {
+               int ret;
+               u64 pfn;
+
+               if (!capable(CAP_SYS_ADMIN))
+                       return -EPERM;
+               if (kstrtoull(buf, 0, &pfn) < 0)
+                       return -EINVAL;
+               pfn >>= PAGE_SHIFT;
+               ret = soft_offline_page(pfn, 0);
+               return ret == 0 ? count : ret;
+       }
+       return 0;
 }
 
 /* Forcibly offline a page, including killing processes. */
@@ -558,22 +566,25 @@ static ssize_t hard_offline_page_store(struct device *dev,
                                       struct device_attribute *attr,
                                       const char *buf, size_t count)
 {
-       int ret;
-       u64 pfn;
-       if (!capable(CAP_SYS_ADMIN))
-               return -EPERM;
-       if (kstrtoull(buf, 0, &pfn) < 0)
-               return -EINVAL;
-       pfn >>= PAGE_SHIFT;
-       ret = memory_failure(pfn, MF_SW_SIMULATED);
-       if (ret == -EOPNOTSUPP)
-               ret = 0;
-       return ret ? ret : count;
+       if (IS_ENABLED(CONFIG_MEMORY_FAILURE)) {
+               int ret;
+               u64 pfn;
+
+               if (!capable(CAP_SYS_ADMIN))
+                       return -EPERM;
+               if (kstrtoull(buf, 0, &pfn) < 0)
+                       return -EINVAL;
+               pfn >>= PAGE_SHIFT;
+               ret = memory_failure(pfn, MF_SW_SIMULATED);
+               if (ret == -EOPNOTSUPP)
+                       ret = 0;
+               return ret ? ret : count;
+       }
+       return 0;
 }
 
 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 +622,35 @@ 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 +910,41 @@ 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[] = {
-- 
2.31.1


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