diff options
| -rw-r--r-- | include/linux/memremap.h | 39 | ||||
| -rw-r--r-- | kernel/memremap.c | 36 |
2 files changed, 38 insertions, 37 deletions
diff --git a/include/linux/memremap.h b/include/linux/memremap.h index d5a6736..26e8aab 100644 --- a/include/linux/memremap.h +++ b/include/linux/memremap.h @@ -133,7 +133,8 @@ struct dev_pagemap { #ifdef CONFIG_ZONE_DEVICE void *devm_memremap_pages(struct device *dev, struct resource *res, struct percpu_ref *ref, struct vmem_altmap *altmap); -struct dev_pagemap *find_dev_pagemap(resource_size_t phys); +struct dev_pagemap *get_dev_pagemap(unsigned long pfn, + struct dev_pagemap *pgmap); unsigned long vmem_altmap_offset(struct vmem_altmap *altmap); void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns); @@ -153,7 +154,8 @@ static inline void *devm_memremap_pages(struct device *dev, return ERR_PTR(-ENXIO); } -static inline struct dev_pagemap *find_dev_pagemap(resource_size_t phys) +static inline struct dev_pagemap *get_dev_pagemap(unsigned long pfn, + struct dev_pagemap *pgmap) { return NULL; } @@ -183,39 +185,6 @@ static inline bool is_device_public_page(const struct page *page) } #endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */ -/** - * 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) diff --git a/kernel/memremap.c b/kernel/memremap.c index 64b12c8..3df6cd4 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -314,7 +314,7 @@ static void devm_memremap_pages_release(struct device *dev, void *data) } /* assumes rcu_read_lock() held at entry */ -struct dev_pagemap *find_dev_pagemap(resource_size_t phys) +static struct dev_pagemap *find_dev_pagemap(resource_size_t phys) { struct page_map *page_map; @@ -501,8 +501,40 @@ struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start) return pgmap ? pgmap->altmap : NULL; } -#endif /* CONFIG_ZONE_DEVICE */ +/** + * 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. + */ +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; +} +#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) |
