/* * 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(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 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 */