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-rw-r--r--mm/memremap.c70
1 files changed, 36 insertions, 34 deletions
diff --git a/mm/memremap.c b/mm/memremap.c
index 6aa5f0c2d11f..af0223605e69 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -4,7 +4,7 @@
#include <linux/io.h>
#include <linux/kasan.h>
#include <linux/memory_hotplug.h>
-#include <linux/mm.h>
+#include <linux/memremap.h>
#include <linux/pfn_t.h>
#include <linux/swap.h>
#include <linux/mmzone.h>
@@ -12,6 +12,7 @@
#include <linux/types.h>
#include <linux/wait_bit.h>
#include <linux/xarray.h>
+#include "internal.h"
static DEFINE_XARRAY(pgmap_array);
@@ -37,21 +38,19 @@ unsigned long memremap_compat_align(void)
EXPORT_SYMBOL_GPL(memremap_compat_align);
#endif
-#ifdef CONFIG_DEV_PAGEMAP_OPS
+#ifdef CONFIG_FS_DAX
DEFINE_STATIC_KEY_FALSE(devmap_managed_key);
EXPORT_SYMBOL(devmap_managed_key);
static void devmap_managed_enable_put(struct dev_pagemap *pgmap)
{
- if (pgmap->type == MEMORY_DEVICE_PRIVATE ||
- pgmap->type == MEMORY_DEVICE_FS_DAX)
+ if (pgmap->type == MEMORY_DEVICE_FS_DAX)
static_branch_dec(&devmap_managed_key);
}
static void devmap_managed_enable_get(struct dev_pagemap *pgmap)
{
- if (pgmap->type == MEMORY_DEVICE_PRIVATE ||
- pgmap->type == MEMORY_DEVICE_FS_DAX)
+ if (pgmap->type == MEMORY_DEVICE_FS_DAX)
static_branch_inc(&devmap_managed_key);
}
#else
@@ -61,7 +60,7 @@ static void devmap_managed_enable_get(struct dev_pagemap *pgmap)
static void devmap_managed_enable_put(struct dev_pagemap *pgmap)
{
}
-#endif /* CONFIG_DEV_PAGEMAP_OPS */
+#endif /* CONFIG_FS_DAX */
static void pgmap_array_delete(struct range *range)
{
@@ -102,23 +101,12 @@ static unsigned long pfn_end(struct dev_pagemap *pgmap, int range_id)
return (range->start + range_len(range)) >> PAGE_SHIFT;
}
-static unsigned long pfn_next(struct dev_pagemap *pgmap, unsigned long pfn)
-{
- if (pfn % (1024 << pgmap->vmemmap_shift))
- cond_resched();
- return pfn + pgmap_vmemmap_nr(pgmap);
-}
-
static unsigned long pfn_len(struct dev_pagemap *pgmap, unsigned long range_id)
{
return (pfn_end(pgmap, range_id) -
pfn_first(pgmap, range_id)) >> pgmap->vmemmap_shift;
}
-#define for_each_device_pfn(pfn, map, i) \
- for (pfn = pfn_first(map, i); pfn < pfn_end(map, i); \
- pfn = pfn_next(map, pfn))
-
static void pageunmap_range(struct dev_pagemap *pgmap, int range_id)
{
struct range *range = &pgmap->ranges[range_id];
@@ -147,13 +135,11 @@ static void pageunmap_range(struct dev_pagemap *pgmap, int range_id)
void memunmap_pages(struct dev_pagemap *pgmap)
{
- unsigned long pfn;
int i;
percpu_ref_kill(&pgmap->ref);
for (i = 0; i < pgmap->nr_range; i++)
- for_each_device_pfn(pfn, pgmap, i)
- put_page(pfn_to_page(pfn));
+ percpu_ref_put_many(&pgmap->ref, pfn_len(pgmap, i));
wait_for_completion(&pgmap->done);
percpu_ref_exit(&pgmap->ref);
@@ -282,7 +268,8 @@ static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params,
return 0;
err_add_memory:
- kasan_remove_zero_shadow(__va(range->start), range_len(range));
+ if (!is_private)
+ kasan_remove_zero_shadow(__va(range->start), range_len(range));
err_kasan:
untrack_pfn(NULL, PHYS_PFN(range->start), range_len(range));
err_pfn_remap:
@@ -328,8 +315,7 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
}
break;
case MEMORY_DEVICE_FS_DAX:
- if (!IS_ENABLED(CONFIG_ZONE_DEVICE) ||
- IS_ENABLED(CONFIG_FS_DAX_LIMITED)) {
+ if (IS_ENABLED(CONFIG_FS_DAX_LIMITED)) {
WARN(1, "File system DAX not supported\n");
return ERR_PTR(-EINVAL);
}
@@ -465,21 +451,15 @@ struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
}
EXPORT_SYMBOL_GPL(get_dev_pagemap);
-#ifdef CONFIG_DEV_PAGEMAP_OPS
-void free_devmap_managed_page(struct page *page)
+void free_zone_device_page(struct page *page)
{
- /* notify page idle for dax */
- if (!is_device_private_page(page)) {
- wake_up_var(&page->_refcount);
+ if (WARN_ON_ONCE(!page->pgmap->ops || !page->pgmap->ops->page_free))
return;
- }
-
- __ClearPageWaiters(page);
mem_cgroup_uncharge(page_folio(page));
/*
- * When a device_private page is freed, the page->mapping field
+ * When a device managed page is freed, the page->mapping field
* may still contain a (stale) mapping value. For example, the
* lower bits of page->mapping may still identify the page as an
* anonymous page. Ultimately, this entire field is just stale
@@ -501,5 +481,27 @@ void free_devmap_managed_page(struct page *page)
*/
page->mapping = NULL;
page->pgmap->ops->page_free(page);
+
+ /*
+ * Reset the page count to 1 to prepare for handing out the page again.
+ */
+ set_page_count(page, 1);
+}
+
+#ifdef CONFIG_FS_DAX
+bool __put_devmap_managed_page(struct page *page)
+{
+ if (page->pgmap->type != MEMORY_DEVICE_FS_DAX)
+ return false;
+
+ /*
+ * fsdax page refcounts are 1-based, rather than 0-based: if
+ * refcount is 1, then the page is free and the refcount is
+ * stable because nobody holds a reference on the page.
+ */
+ if (page_ref_dec_return(page) == 1)
+ wake_up_var(&page->_refcount);
+ return true;
}
-#endif /* CONFIG_DEV_PAGEMAP_OPS */
+EXPORT_SYMBOL(__put_devmap_managed_page);
+#endif /* CONFIG_FS_DAX */