/* * 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_DEVICEstruct 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 */