/* SPDX-License-Identifier: GPL-2.0 */#include <linux/device.h>#include <linux/types.h>#include <linux/io.h>#include <linux/mm.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 #ifndef arch_memremap_wbstatic void *arch_memremap_wb(resource_size_t offset, unsigned long size){	return (__force void *)ioremap_cache(offset, size);}#endif #ifndef arch_memremap_can_ram_remapstatic bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,					unsigned long flags){	return true;}#endif static void *try_ram_remap(resource_size_t offset, size_t size,			   unsigned long flags){	unsigned long pfn = PHYS_PFN(offset); 	/* In the simple case just return the existing linear address */	if (pfn_valid(pfn) && !PageHighMem(pfn_to_page(pfn)) &&	    arch_memremap_can_ram_remap(offset, size, flags))		return __va(offset); 	return NULL; /* fallback to arch_memremap_wb */} /** * memremap() - remap an iomem_resource as cacheable memory * @offset: iomem resource start address * @size: size of remap * @flags: any of MEMREMAP_WB, MEMREMAP_WT, MEMREMAP_WC, *		  MEMREMAP_ENC, MEMREMAP_DEC * * 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. In the case of multiple flags, the different * mapping types will be attempted in the order listed below until one of * them succeeds. * * MEMREMAP_WB - matches the default mapping for System RAM on * the architecture.  This is usually a read-allocate write-back cache. * Moreover, 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. * * MEMREMAP_WC - establish a writecombine mapping, whereby writes may * be coalesced together (e.g. in the CPU's write buffers), but is otherwise * uncached. 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,				       IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);	void *addr = NULL; 	if (!flags)		return 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) {		/*		 * MEMREMAP_WB is special in that it can be satisfied		 * 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, flags);		if (!addr)			addr = arch_memremap_wb(offset, size);	} 	/*	 * If we don't have a mapping yet and other request flags are	 * present 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 != MEMREMAP_WB) {		WARN_ONCE(1, "memremap attempted on ram %pa size: %#lx\n",				&offset, (unsigned long) size);		return NULL;	} 	if (!addr && (flags & MEMREMAP_WT))		addr = ioremap_wt(offset, size); 	if (!addr && (flags & MEMREMAP_WC))		addr = ioremap_wc(offset, size); 	return addr;}EXPORT_SYMBOL(memremap); void memunmap(void *addr){	if (is_ioremap_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);