diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/list.h | 11 | ||||
| -rw-r--r-- | include/linux/memremap.h | 49 | ||||
| -rw-r--r-- | include/linux/mm_types.h | 5 |
3 files changed, 63 insertions, 2 deletions
diff --git a/include/linux/list.h b/include/linux/list.h index 5356f4d661a7..30cf4200ab40 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -113,6 +113,17 @@ extern void __list_del_entry(struct list_head *entry); extern void list_del(struct list_head *entry); #endif +#ifdef CONFIG_DEBUG_LIST +/* + * See devm_memremap_pages() which wants DEBUG_LIST=y to assert if one + * of the pages it allocates is ever passed to list_add() + */ +extern void list_force_poison(struct list_head *entry); +#else +/* fallback to the less strict LIST_POISON* definitions */ +#define list_force_poison list_del +#endif + /** * list_replace - replace old entry by new one * @old : the element to be replaced diff --git a/include/linux/memremap.h b/include/linux/memremap.h index aa3e82a80d7b..bcaa634139a9 100644 --- a/include/linux/memremap.h +++ b/include/linux/memremap.h @@ -1,6 +1,8 @@ #ifndef _LINUX_MEMREMAP_H_ #define _LINUX_MEMREMAP_H_ #include <linux/mm.h> +#include <linux/ioport.h> +#include <linux/percpu-refcount.h> struct resource; struct device; @@ -36,21 +38,25 @@ static inline struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start) /** * struct dev_pagemap - metadata for ZONE_DEVICE mappings * @altmap: pre-allocated/reserved memory for vmemmap allocations + * @res: physical address range covered by @ref + * @ref: reference count that pins the devm_memremap_pages() mapping * @dev: host device of the mapping for debug */ struct dev_pagemap { struct vmem_altmap *altmap; const struct resource *res; + struct percpu_ref *ref; struct device *dev; }; #ifdef CONFIG_ZONE_DEVICE void *devm_memremap_pages(struct device *dev, struct resource *res, - struct vmem_altmap *altmap); + struct percpu_ref *ref, struct vmem_altmap *altmap); struct dev_pagemap *find_dev_pagemap(resource_size_t phys); #else static inline void *devm_memremap_pages(struct device *dev, - struct resource *res, struct vmem_altmap *altmap) + struct resource *res, struct percpu_ref *ref, + struct vmem_altmap *altmap) { /* * Fail attempts to call devm_memremap_pages() without @@ -66,4 +72,43 @@ static inline struct dev_pagemap *find_dev_pagemap(resource_size_t phys) return NULL; } #endif + +/** + * 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 + * + * @pgmap allows the overhead of a lookup to be bypassed when @pfn lands in the + * same mapping. + */ +static inline struct dev_pagemap *get_dev_pagemap(unsigned long pfn, + struct dev_pagemap *pgmap) +{ + const struct resource *res = pgmap ? pgmap->res : NULL; + resource_size_t phys = PFN_PHYS(pfn); + + /* + * In the cached case we're already holding a live reference so + * we can simply do a blind increment + */ + if (res && phys >= res->start && phys <= res->end) { + percpu_ref_get(pgmap->ref); + return pgmap; + } + + /* fall back to slow path lookup */ + rcu_read_lock(); + pgmap = find_dev_pagemap(phys); + if (pgmap && !percpu_ref_tryget_live(pgmap->ref)) + pgmap = NULL; + rcu_read_unlock(); + + return pgmap; +} + +static inline void put_dev_pagemap(struct dev_pagemap *pgmap) +{ + if (pgmap) + percpu_ref_put(pgmap->ref); +} #endif /* _LINUX_MEMREMAP_H_ */ diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 2dd9c313a8c0..d3ebb9d21a53 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -116,6 +116,11 @@ struct page { * Can be used as a generic list * by the page owner. */ + struct dev_pagemap *pgmap; /* ZONE_DEVICE pages are never on an + * lru or handled by a slab + * allocator, this points to the + * hosting device page map. + */ struct { /* slub per cpu partial pages */ struct page *next; /* Next partial slab */ #ifdef CONFIG_64BIT |