diff options
Diffstat (limited to 'kernel/memremap.c')
| -rw-r--r-- | kernel/memremap.c | 72 |
1 files changed, 70 insertions, 2 deletions
diff --git a/kernel/memremap.c b/kernel/memremap.c index 61cfbf4d3054..562f6471fe90 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -166,6 +166,7 @@ struct page_map { struct resource res; struct percpu_ref *ref; struct dev_pagemap pgmap; + struct vmem_altmap altmap; }; static void pgmap_radix_release(struct resource *res) @@ -183,6 +184,7 @@ static void devm_memremap_pages_release(struct device *dev, void *data) struct page_map *page_map = data; struct resource *res = &page_map->res; resource_size_t align_start, align_size; + struct dev_pagemap *pgmap = &page_map->pgmap; pgmap_radix_release(res); @@ -190,6 +192,8 @@ static void devm_memremap_pages_release(struct device *dev, void *data) align_start = res->start & ~(SECTION_SIZE - 1); align_size = ALIGN(resource_size(res), SECTION_SIZE); arch_remove_memory(align_start, align_size); + 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 */ @@ -203,11 +207,23 @@ struct dev_pagemap *find_dev_pagemap(resource_size_t phys) return page_map ? &page_map->pgmap : NULL; } -void *devm_memremap_pages(struct device *dev, struct resource *res) +/** + * devm_memremap_pages - remap and provide memmap backing for the given resource + * @dev: hosting device for @res + * @res: "host memory" address range + * @altmap: optional descriptor for allocating the memmap from @res + * + * Note, the expectation is that @res is 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 vmem_altmap *altmap) { int is_ram = region_intersects(res->start, resource_size(res), "System RAM"); resource_size_t key, align_start, align_size; + struct dev_pagemap *pgmap; struct page_map *page_map; int error, nid; @@ -220,14 +236,27 @@ void *devm_memremap_pages(struct device *dev, struct resource *res) if (is_ram == REGION_INTERSECTS) return __va(res->start); + if (altmap && !IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP)) { + dev_err(dev, "%s: altmap requires CONFIG_SPARSEMEM_VMEMMAP=y\n", + __func__); + return ERR_PTR(-ENXIO); + } + 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)); - page_map->pgmap.dev = dev; + pgmap->dev = dev; + if (altmap) { + memcpy(&page_map->altmap, altmap, sizeof(*altmap)); + pgmap->altmap = &page_map->altmap; + } + pgmap->res = &page_map->res; + mutex_lock(&pgmap_lock); error = 0; for (key = res->start; key <= res->end; key += SECTION_SIZE) { @@ -273,4 +302,43 @@ void *devm_memremap_pages(struct device *dev, struct resource *res) return ERR_PTR(error); } EXPORT_SYMBOL(devm_memremap_pages); + +unsigned long vmem_altmap_offset(struct vmem_altmap *altmap) +{ + /* number of pfns from base where pfn_to_page() is valid */ + return altmap->reserve + altmap->free; +} + +void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns) +{ + altmap->alloc -= nr_pfns; +} + +#ifdef CONFIG_SPARSEMEM_VMEMMAP +struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start) +{ + /* + * 'memmap_start' is the virtual address for the first "struct + * page" in this range of the vmemmap array. In the case of + * CONFIG_SPARSE_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; + + /* + * Uncoditionally 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. + */ + rcu_read_lock(); + pgmap = find_dev_pagemap(__pfn_to_phys(page_to_pfn(page))); + rcu_read_unlock(); + + return pgmap ? pgmap->altmap : NULL; +} +#endif /* CONFIG_SPARSEMEM_VMEMMAP */ #endif /* CONFIG_ZONE_DEVICE */ |