Merge tag 'nfsd-4.12-1' of git://linux-nfs.org/~bfields/linux

[karo-tx-linux.git] / kernel / memremap.c

diff --git a/kernel/memremap.c b/kernel/memremap.c
index 9ecedc28b928debb6a5988a5db8b76833133d9e4..23a6483c3666e35fec7f927d2f6cd4a2e38dbe81 100644 (file)
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -182,18 +182,6 @@ struct page_map {
        struct vmem_altmap altmap;
 };
 
-void get_zone_device_page(struct page *page)
-{
-       percpu_ref_get(page->pgmap->ref);
-}
-EXPORT_SYMBOL(get_zone_device_page);
-
-void put_zone_device_page(struct page *page)
-{
-       put_dev_pagemap(page->pgmap);
-}
-EXPORT_SYMBOL(put_zone_device_page);
-
 static void pgmap_radix_release(struct resource *res)
 {
        resource_size_t key, align_start, align_size, align_end;
@@ -237,6 +225,10 @@ static void devm_memremap_pages_release(struct device *dev, void *data)
        struct resource *res = &page_map->res;
        resource_size_t align_start, align_size;
        struct dev_pagemap *pgmap = &page_map->pgmap;
+       unsigned long pfn;
+
+       for_each_device_pfn(pfn, page_map)
+               put_page(pfn_to_page(pfn));
 
        if (percpu_ref_tryget_live(pgmap->ref)) {
                dev_WARN(dev, "%s: page mapping is still live!\n", __func__);
@@ -246,9 +238,11 @@ static void devm_memremap_pages_release(struct device *dev, void *data)
        /* pages are dead and unused, undo the arch mapping */
        align_start = res->start & ~(SECTION_SIZE - 1);
        align_size = ALIGN(resource_size(res), SECTION_SIZE);
+
        mem_hotplug_begin();
        arch_remove_memory(align_start, align_size);
        mem_hotplug_done();
+
        untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
        pgmap_radix_release(res);
        dev_WARN_ONCE(dev, pgmap->altmap && pgmap->altmap->alloc,
@@ -275,7 +269,10 @@ struct dev_pagemap *find_dev_pagemap(resource_size_t phys)
  *
  * Notes:
  * 1/ @ref must be 'live' on entry and 'dead' before devm_memunmap_pages() time
- *    (or devm release event).
+ *    (or devm release event). The expected order of events is that @ref has
+ *    been through percpu_ref_kill() before devm_memremap_pages_release(). The
+ *    wait for the completion of all references being dropped and
+ *    percpu_ref_exit() must occur after devm_memremap_pages_release().
  *
  * 2/ @res is expected to be a host memory range that could feasibly be
  *    treated as a "System RAM" range, i.e. not a device mmio range, but
@@ -377,6 +374,7 @@ void *devm_memremap_pages(struct device *dev, struct resource *res,
                 */
                list_del(&page->lru);
                page->pgmap = pgmap;
+               percpu_ref_get(ref);
        }
        devres_add(dev, page_map);
        return __va(res->start);