| /* |
| * Copyright(c) 2015 Intel Corporation. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of version 2 of the GNU General Public License as |
| * published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| */ |
| #include <linux/device.h> |
| #include <linux/types.h> |
| #include <linux/io.h> |
| #include <linux/mm.h> |
| #include <linux/memory_hotplug.h> |
| |
| #ifndef ioremap_cache |
| /* temporary while we convert existing ioremap_cache users to memremap */ |
| __weak void __iomem *ioremap_cache(resource_size_t offset, unsigned long size) |
| { |
| return ioremap(offset, size); |
| } |
| #endif |
| |
| static void *try_ram_remap(resource_size_t offset, size_t size) |
| { |
| struct page *page = pfn_to_page(offset >> PAGE_SHIFT); |
| |
| /* In the simple case just return the existing linear address */ |
| if (!PageHighMem(page)) |
| return __va(offset); |
| return NULL; /* fallback to ioremap_cache */ |
| } |
| |
| /** |
| * memremap() - remap an iomem_resource as cacheable memory |
| * @offset: iomem resource start address |
| * @size: size of remap |
| * @flags: either MEMREMAP_WB or MEMREMAP_WT |
| * |
| * memremap() is "ioremap" for cases where it is known that the resource |
| * being mapped does not have i/o side effects and the __iomem |
| * annotation is not applicable. |
| * |
| * MEMREMAP_WB - matches the default mapping for "System RAM" on |
| * the architecture. This is usually a read-allocate write-back cache. |
| * Morever, if MEMREMAP_WB is specified and the requested remap region is RAM |
| * memremap() will bypass establishing a new mapping and instead return |
| * a pointer into the direct map. |
| * |
| * MEMREMAP_WT - establish a mapping whereby writes either bypass the |
| * cache or are written through to memory and never exist in a |
| * cache-dirty state with respect to program visibility. Attempts to |
| * map "System RAM" with this mapping type will fail. |
| */ |
| void *memremap(resource_size_t offset, size_t size, unsigned long flags) |
| { |
| int is_ram = region_intersects(offset, size, "System RAM"); |
| void *addr = NULL; |
| |
| if (is_ram == REGION_MIXED) { |
| WARN_ONCE(1, "memremap attempted on mixed range %pa size: %#lx\n", |
| &offset, (unsigned long) size); |
| return NULL; |
| } |
| |
| /* Try all mapping types requested until one returns non-NULL */ |
| if (flags & MEMREMAP_WB) { |
| flags &= ~MEMREMAP_WB; |
| /* |
| * MEMREMAP_WB is special in that it can be satisifed |
| * from the direct map. Some archs depend on the |
| * capability of memremap() to autodetect cases where |
| * the requested range is potentially in "System RAM" |
| */ |
| if (is_ram == REGION_INTERSECTS) |
| addr = try_ram_remap(offset, size); |
| if (!addr) |
| addr = ioremap_cache(offset, size); |
| } |
| |
| /* |
| * If we don't have a mapping yet and more request flags are |
| * pending then we will be attempting to establish a new virtual |
| * address mapping. Enforce that this mapping is not aliasing |
| * "System RAM" |
| */ |
| if (!addr && is_ram == REGION_INTERSECTS && flags) { |
| WARN_ONCE(1, "memremap attempted on ram %pa size: %#lx\n", |
| &offset, (unsigned long) size); |
| return NULL; |
| } |
| |
| if (!addr && (flags & MEMREMAP_WT)) { |
| flags &= ~MEMREMAP_WT; |
| addr = ioremap_wt(offset, size); |
| } |
| |
| return addr; |
| } |
| EXPORT_SYMBOL(memremap); |
| |
| void memunmap(void *addr) |
| { |
| if (is_vmalloc_addr(addr)) |
| iounmap((void __iomem *) addr); |
| } |
| EXPORT_SYMBOL(memunmap); |
| |
| static void devm_memremap_release(struct device *dev, void *res) |
| { |
| memunmap(*(void **)res); |
| } |
| |
| static int devm_memremap_match(struct device *dev, void *res, void *match_data) |
| { |
| return *(void **)res == match_data; |
| } |
| |
| void *devm_memremap(struct device *dev, resource_size_t offset, |
| size_t size, unsigned long flags) |
| { |
| void **ptr, *addr; |
| |
| ptr = devres_alloc_node(devm_memremap_release, sizeof(*ptr), GFP_KERNEL, |
| dev_to_node(dev)); |
| if (!ptr) |
| return ERR_PTR(-ENOMEM); |
| |
| addr = memremap(offset, size, flags); |
| if (addr) { |
| *ptr = addr; |
| devres_add(dev, ptr); |
| } else { |
| devres_free(ptr); |
| return ERR_PTR(-ENXIO); |
| } |
| |
| return addr; |
| } |
| EXPORT_SYMBOL(devm_memremap); |
| |
| void devm_memunmap(struct device *dev, void *addr) |
| { |
| WARN_ON(devres_release(dev, devm_memremap_release, |
| devm_memremap_match, addr)); |
| } |
| EXPORT_SYMBOL(devm_memunmap); |
| |
| #ifdef CONFIG_ZONE_DEVICE |
| struct page_map { |
| struct resource res; |
| }; |
| |
| static void devm_memremap_pages_release(struct device *dev, void *res) |
| { |
| struct page_map *page_map = res; |
| |
| /* pages are dead and unused, undo the arch mapping */ |
| arch_remove_memory(page_map->res.start, resource_size(&page_map->res)); |
| } |
| |
| void *devm_memremap_pages(struct device *dev, struct resource *res) |
| { |
| int is_ram = region_intersects(res->start, resource_size(res), |
| "System RAM"); |
| struct page_map *page_map; |
| int error, nid; |
| |
| if (is_ram == REGION_MIXED) { |
| WARN_ONCE(1, "%s attempted on mixed region %pr\n", |
| __func__, res); |
| return ERR_PTR(-ENXIO); |
| } |
| |
| if (is_ram == REGION_INTERSECTS) |
| return __va(res->start); |
| |
| 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); |
| |
| memcpy(&page_map->res, res, sizeof(*res)); |
| |
| nid = dev_to_node(dev); |
| if (nid < 0) |
| nid = numa_mem_id(); |
| |
| error = arch_add_memory(nid, res->start, resource_size(res), true); |
| if (error) { |
| devres_free(page_map); |
| return ERR_PTR(error); |
| } |
| |
| devres_add(dev, page_map); |
| return __va(res->start); |
| } |
| EXPORT_SYMBOL(devm_memremap_pages); |
| #endif /* CONFIG_ZONE_DEVICE */ |