@@ -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
/**
@@ -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
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 <khandual@linux.vnet.ibm.com> --- include/linux/memremap.h | 18 ++++++++++++++++++ kernel/memremap.c | 15 +++++++++++++-- 2 files changed, 31 insertions(+), 2 deletions(-)