[RFC 5/7] mm/memremap: Export pfn_first, pfn_end, find_pagemap functions
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From: Anshuman Khandual <hidden>
Date: 2016-05-03 06:30:27
Subsystem:
memory hot(un)plug, the rest · Maintainers:
David Hildenbrand, Oscar Salvador, Linus Torvalds
This change exports two existing functions pfn_first, pfn_end and also defines a new one called find_pagemap. These functions are required to navigate through the memory which is hotplugged into the ZONE_DEVICE as device memory. Signed-off-by: Anshuman Khandual <redacted> --- include/linux/memremap.h | 18 ++++++++++++++++++ kernel/memremap.c | 15 +++++++++++++-- 2 files changed, 31 insertions(+), 2 deletions(-)
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index bcaa634..b193044 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h@@ -28,11 +28,29 @@ void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns); #if defined(CONFIG_SPARSEMEM_VMEMMAP) && defined(CONFIG_ZONE_DEVICE) struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start); +struct page_map *find_pagemap(resource_size_t phys); +unsigned long pfn_first(struct page_map *pgmap); +unsigned long pfn_end(struct page_map *pgmap); #else static inline struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start) { return NULL; } + +static inline struct page_map *find_pagemap(resource_size_t phys) +{ + return NULL; +} + +unsigned long pfn_first(struct page_map *pgmap) +{ + return 0; +} + +unsigned long pfn_end(struct page_map *pgmap) +{ + return 0; +} #endif /**
diff --git a/kernel/memremap.c b/kernel/memremap.c
index a6d3823..3c21051 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c@@ -207,7 +207,7 @@ static void pgmap_radix_release(struct resource *res) mutex_unlock(&pgmap_lock); } -static unsigned long pfn_first(struct page_map *page_map) +unsigned long pfn_first(struct page_map *page_map) { struct dev_pagemap *pgmap = &page_map->pgmap; const struct resource *res = &page_map->res;
@@ -220,7 +220,7 @@ static unsigned long pfn_first(struct page_map *page_map) return pfn; } -static unsigned long pfn_end(struct page_map *page_map) +unsigned long pfn_end(struct page_map *page_map) { const struct resource *res = &page_map->res;
@@ -262,6 +262,17 @@ struct dev_pagemap *find_dev_pagemap(resource_size_t phys) return page_map ? &page_map->pgmap : NULL; } +struct page_map *find_pagemap(resource_size_t phys) +{ + struct page_map *page_map; + + rcu_read_lock(); + page_map = radix_tree_lookup(&pgmap_radix, phys >> PA_SECTION_SHIFT); + rcu_read_unlock(); + + return page_map; +} + /** * devm_memremap_pages - remap and provide memmap backing for the given resource * @dev: hosting device for @res
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1.8.3.1