#define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1)
#define SECTION_SIZE (1UL << PA_SECTION_SHIFT)
-struct page_map {
- struct resource res;
- struct percpu_ref *ref;
- struct dev_pagemap pgmap;
- struct vmem_altmap altmap;
-};
-
static unsigned long order_at(struct resource *res, unsigned long pgoff)
{
unsigned long phys_pgoff = PHYS_PFN(res->start) + pgoff;
EXPORT_SYMBOL(device_private_entry_fault);
#endif /* CONFIG_DEVICE_PRIVATE */
-static void pgmap_radix_release(struct resource *res)
+static void pgmap_radix_release(struct resource *res, unsigned long end_pgoff)
{
unsigned long pgoff, order;
mutex_lock(&pgmap_lock);
- foreach_order_pgoff(res, order, pgoff)
+ foreach_order_pgoff(res, order, pgoff) {
+ if (pgoff >= end_pgoff)
+ break;
radix_tree_delete(&pgmap_radix, PHYS_PFN(res->start) + pgoff);
+ }
mutex_unlock(&pgmap_lock);
synchronize_rcu();
}
-static unsigned long pfn_first(struct page_map *page_map)
+static unsigned long pfn_first(struct dev_pagemap *pgmap)
{
- struct dev_pagemap *pgmap = &page_map->pgmap;
- const struct resource *res = &page_map->res;
- struct vmem_altmap *altmap = pgmap->altmap;
+ const struct resource *res = &pgmap->res;
+ struct vmem_altmap *altmap = &pgmap->altmap;
unsigned long pfn;
pfn = res->start >> PAGE_SHIFT;
- if (altmap)
+ if (pgmap->altmap_valid)
pfn += vmem_altmap_offset(altmap);
return pfn;
}
-static unsigned long pfn_end(struct page_map *page_map)
+static unsigned long pfn_end(struct dev_pagemap *pgmap)
{
- const struct resource *res = &page_map->res;
+ const struct resource *res = &pgmap->res;
return (res->start + resource_size(res)) >> PAGE_SHIFT;
}
#define for_each_device_pfn(pfn, map) \
for (pfn = pfn_first(map); pfn < pfn_end(map); pfn++)
-static void devm_memremap_pages_release(struct device *dev, void *data)
+static void devm_memremap_pages_release(void *data)
{
- struct page_map *page_map = data;
- struct resource *res = &page_map->res;
+ struct dev_pagemap *pgmap = data;
+ struct device *dev = pgmap->dev;
+ struct resource *res = &pgmap->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)
+ for_each_device_pfn(pfn, pgmap)
put_page(pfn_to_page(pfn));
if (percpu_ref_tryget_live(pgmap->ref)) {
/* pages are dead and unused, undo the arch mapping */
align_start = res->start & ~(SECTION_SIZE - 1);
- align_size = ALIGN(resource_size(res), SECTION_SIZE);
+ align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)
+ - align_start;
mem_hotplug_begin();
- arch_remove_memory(align_start, align_size);
+ arch_remove_memory(align_start, align_size, pgmap->altmap_valid ?
+ &pgmap->altmap : NULL);
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,
- "%s: failed to free all reserved pages\n", __func__);
-}
-
-/* assumes rcu_read_lock() held at entry */
-struct dev_pagemap *find_dev_pagemap(resource_size_t phys)
-{
- struct page_map *page_map;
-
- WARN_ON_ONCE(!rcu_read_lock_held());
-
- page_map = radix_tree_lookup(&pgmap_radix, PHYS_PFN(phys));
- return page_map ? &page_map->pgmap : NULL;
+ pgmap_radix_release(res, -1);
+ dev_WARN_ONCE(dev, pgmap->altmap.alloc,
+ "%s: failed to free all reserved pages\n", __func__);
}
/**
* devm_memremap_pages - remap and provide memmap backing for the given resource
* @dev: hosting device for @res
- * @res: "host memory" address range
- * @ref: a live per-cpu reference count
- * @altmap: optional descriptor for allocating the memmap from @res
+ * @pgmap: pointer to a struct dev_pgmap
*
* Notes:
- * 1/ @ref must be 'live' on entry and 'dead' before devm_memunmap_pages() time
- * (or devm release event). The expected order of events is that @ref has
+ * 1/ At a minimum the res, ref and type members of @pgmap must be initialized
+ * by the caller before passing it to this function
+ *
+ * 2/ The altmap field may optionally be initialized, in which case altmap_valid
+ * must be set to true
+ *
+ * 3/ pgmap.ref must be 'live' on entry and 'dead' before devm_memunmap_pages()
+ * time (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
+ * 4/ 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
* this is not enforced.
*/
-void *devm_memremap_pages(struct device *dev, struct resource *res,
- struct percpu_ref *ref, struct vmem_altmap *altmap)
+void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
{
resource_size_t align_start, align_size, align_end;
+ struct vmem_altmap *altmap = pgmap->altmap_valid ?
+ &pgmap->altmap : NULL;
unsigned long pfn, pgoff, order;
pgprot_t pgprot = PAGE_KERNEL;
- struct dev_pagemap *pgmap;
- struct page_map *page_map;
int error, nid, is_ram, i = 0;
+ struct resource *res = &pgmap->res;
align_start = res->start & ~(SECTION_SIZE - 1);
align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)
if (is_ram == REGION_INTERSECTS)
return __va(res->start);
- if (!ref)
+ if (!pgmap->ref)
return ERR_PTR(-EINVAL);
- page_map = devres_alloc_node(devm_memremap_pages_release,
- sizeof(*page_map), GFP_KERNEL, dev_to_node(dev));
- if (!page_map)
- return ERR_PTR(-ENOMEM);
- pgmap = &page_map->pgmap;
-
- memcpy(&page_map->res, res, sizeof(*res));
-
pgmap->dev = dev;
- if (altmap) {
- memcpy(&page_map->altmap, altmap, sizeof(*altmap));
- pgmap->altmap = &page_map->altmap;
- }
- pgmap->ref = ref;
- pgmap->res = &page_map->res;
- pgmap->type = MEMORY_DEVICE_HOST;
- pgmap->page_fault = NULL;
- pgmap->page_free = NULL;
- pgmap->data = NULL;
mutex_lock(&pgmap_lock);
error = 0;
align_end = align_start + align_size - 1;
foreach_order_pgoff(res, order, pgoff) {
- struct dev_pagemap *dup;
-
- rcu_read_lock();
- dup = find_dev_pagemap(res->start + PFN_PHYS(pgoff));
- rcu_read_unlock();
- if (dup) {
- dev_err(dev, "%s: %pr collides with mapping for %s\n",
- __func__, res, dev_name(dup->dev));
- error = -EBUSY;
- break;
- }
error = __radix_tree_insert(&pgmap_radix,
- PHYS_PFN(res->start) + pgoff, order, page_map);
+ PHYS_PFN(res->start) + pgoff, order, pgmap);
if (error) {
dev_err(dev, "%s: failed: %d\n", __func__, error);
break;
goto err_pfn_remap;
mem_hotplug_begin();
- error = arch_add_memory(nid, align_start, align_size, false);
+ error = arch_add_memory(nid, align_start, align_size, altmap, false);
if (!error)
move_pfn_range_to_zone(&NODE_DATA(nid)->node_zones[ZONE_DEVICE],
align_start >> PAGE_SHIFT,
- align_size >> PAGE_SHIFT);
+ align_size >> PAGE_SHIFT, altmap);
mem_hotplug_done();
if (error)
goto err_add_memory;
- for_each_device_pfn(pfn, page_map) {
+ for_each_device_pfn(pfn, pgmap) {
struct page *page = pfn_to_page(pfn);
/*
*/
list_del(&page->lru);
page->pgmap = pgmap;
- percpu_ref_get(ref);
+ percpu_ref_get(pgmap->ref);
if (!(++i % 1024))
cond_resched();
}
- devres_add(dev, page_map);
+
+ devm_add_action(dev, devm_memremap_pages_release, pgmap);
+
return __va(res->start);
err_add_memory:
untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
err_pfn_remap:
err_radix:
- pgmap_radix_release(res);
- devres_free(page_map);
+ pgmap_radix_release(res, pgoff);
+ devres_free(pgmap);
return ERR_PTR(error);
}
EXPORT_SYMBOL(devm_memremap_pages);
altmap->alloc -= nr_pfns;
}
-struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start)
+/**
+ * get_dev_pagemap() - take a new live reference on the dev_pagemap for @pfn
+ * @pfn: page frame number to lookup page_map
+ * @pgmap: optional known pgmap that already has a reference
+ *
+ * If @pgmap is non-NULL and covers @pfn it will be returned as-is. If @pgmap
+ * is non-NULL but does not cover @pfn the reference to it will be released.
+ */
+struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
+ struct dev_pagemap *pgmap)
{
- /*
- * 'memmap_start' is the virtual address for the first "struct
- * page" in this range of the vmemmap array. In the case of
- * CONFIG_SPARSEMEM_VMEMMAP a page_to_pfn conversion is simple
- * pointer arithmetic, so we can perform this to_vmem_altmap()
- * conversion without concern for the initialization state of
- * the struct page fields.
- */
- struct page *page = (struct page *) memmap_start;
- struct dev_pagemap *pgmap;
+ resource_size_t phys = PFN_PHYS(pfn);
/*
- * Unconditionally retrieve a dev_pagemap associated with the
- * given physical address, this is only for use in the
- * arch_{add|remove}_memory() for setting up and tearing down
- * the memmap.
+ * In the cached case we're already holding a live reference.
*/
+ if (pgmap) {
+ if (phys >= pgmap->res.start && phys <= pgmap->res.end)
+ return pgmap;
+ put_dev_pagemap(pgmap);
+ }
+
+ /* fall back to slow path lookup */
rcu_read_lock();
- pgmap = find_dev_pagemap(__pfn_to_phys(page_to_pfn(page)));
+ pgmap = radix_tree_lookup(&pgmap_radix, PHYS_PFN(phys));
+ if (pgmap && !percpu_ref_tryget_live(pgmap->ref))
+ pgmap = NULL;
rcu_read_unlock();
- return pgmap ? pgmap->altmap : NULL;
+ return pgmap;
}
#endif /* CONFIG_ZONE_DEVICE */
-
#if IS_ENABLED(CONFIG_DEVICE_PRIVATE) || IS_ENABLED(CONFIG_DEVICE_PUBLIC)
void put_zone_device_private_or_public_page(struct page *page)
{
git.samba.org / sfrench / cifs-2.6.git / blobdiff