/* * 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/radix-tree.h>#include <linux/device.h>#include <linux/types.h>#include <linux/pfn_t.h>#include <linux/io.h>#include <linux/mm.h>#include <linux/memory_hotplug.h>#include <linux/swap.h>#include <linux/swapops.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. * 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. * * 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 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, 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_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_DEVICEstatic DEFINE_MUTEX(pgmap_lock);static RADIX_TREE(pgmap_radix, GFP_KERNEL);#define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1)#define SECTION_SIZE (1UL << PA_SECTION_SHIFT) static unsigned long order_at(struct resource *res, unsigned long pgoff){	unsigned long phys_pgoff = PHYS_PFN(res->start) + pgoff;	unsigned long nr_pages, mask; 	nr_pages = PHYS_PFN(resource_size(res));	if (nr_pages == pgoff)		return ULONG_MAX; 	/*	 * What is the largest aligned power-of-2 range available from	 * this resource pgoff to the end of the resource range,	 * considering the alignment of the current pgoff?	 */	mask = phys_pgoff | rounddown_pow_of_two(nr_pages - pgoff);	if (!mask)		return ULONG_MAX; 	return find_first_bit(&mask, BITS_PER_LONG);} #define foreach_order_pgoff(res, order, pgoff) \	for (pgoff = 0, order = order_at((res), pgoff); order < ULONG_MAX; \			pgoff += 1UL << order, order = order_at((res), pgoff)) #if IS_ENABLED(CONFIG_DEVICE_PRIVATE)int device_private_entry_fault(struct vm_area_struct *vma,		       unsigned long addr,		       swp_entry_t entry,		       unsigned int flags,		       pmd_t *pmdp){	struct page *page = device_private_entry_to_page(entry); 	/*	 * The page_fault() callback must migrate page back to system memory	 * so that CPU can access it. This might fail for various reasons	 * (device issue, device was unsafely unplugged, ...). When such	 * error conditions happen, the callback must return VM_FAULT_SIGBUS.	 *	 * Note that because memory cgroup charges are accounted to the device	 * memory, this should never fail because of memory restrictions (but	 * allocation of regular system page might still fail because we are	 * out of memory).	 *	 * There is a more in-depth description of what that callback can and	 * cannot do, in include/linux/memremap.h	 */	return page->pgmap->page_fault(vma, addr, page, flags, pmdp);}EXPORT_SYMBOL(device_private_entry_fault);#endif /* CONFIG_DEVICE_PRIVATE */ static void pgmap_radix_release(struct resource *res, unsigned long end_pgoff){	unsigned long pgoff, order; 	mutex_lock(&pgmap_lock);	foreach_order_pgoff(res, order, pgoff) {		if (pgoff >= end_pgoff)			break;		radix_tree_delete(&pgmap_radix, PHYS_PFN(res->start) + pgoff);	}	mutex_unlock(&pgmap_lock); 	synchronize_rcu();} static unsigned long pfn_first(struct dev_pagemap *pgmap){	const struct resource *res = &pgmap->res;	struct vmem_altmap *altmap = &pgmap->altmap;	unsigned long pfn; 	pfn = res->start >> PAGE_SHIFT;	if (pgmap->altmap_valid)		pfn += vmem_altmap_offset(altmap);	return pfn;} static unsigned long pfn_end(struct dev_pagemap *pgmap){	const struct resource *res = &pgmap->res; 	return (res->start + resource_size(res)) >> PAGE_SHIFT;} static unsigned long pfn_next(unsigned long pfn){	if (pfn % 1024 == 0)		cond_resched();	return pfn + 1;} #define for_each_device_pfn(pfn, map) \	for (pfn = pfn_first(map); pfn < pfn_end(map); pfn = pfn_next(pfn)) static void devm_memremap_pages_release(void *data){	struct dev_pagemap *pgmap = data;	struct device *dev = pgmap->dev;	struct resource *res = &pgmap->res;	resource_size_t align_start, align_size;	unsigned long pfn; 	for_each_device_pfn(pfn, pgmap)		put_page(pfn_to_page(pfn)); 	if (percpu_ref_tryget_live(pgmap->ref)) {		dev_WARN(dev, "%s: page mapping is still live!\n", __func__);		percpu_ref_put(pgmap->ref);	} 	/* pages are dead and unused, undo the arch mapping */	align_start = res->start & ~(SECTION_SIZE - 1);	align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)		- align_start; 	mem_hotplug_begin();	arch_remove_memory(align_start, align_size, pgmap->altmap_valid ?			&pgmap->altmap : NULL);	mem_hotplug_done(); 	untrack_pfn(NULL, PHYS_PFN(align_start), align_size);	pgmap_radix_release(res, -1);	dev_WARN_ONCE(dev, pgmap->altmap.alloc,		      "%s: failed to free all reserved pages\n", __func__);} /** * devm_memremap_pages - remap and provide memmap backing for the given resource * @dev: hosting device for @res * @pgmap: pointer to a struct dev_pgmap * * Notes: * 1/ At a minimum the res, ref and type members of @pgmap must be initialized *    by the caller before passing it to this function * * 2/ The altmap field may optionally be initialized, in which case altmap_valid *    must be set to true * * 3/ pgmap.ref must be 'live' on entry and 'dead' before devm_memunmap_pages() *    time (or devm release event). The expected order of events is that ref has *    been through percpu_ref_kill() before devm_memremap_pages_release(). The *    wait for the completion of all references being dropped and *    percpu_ref_exit() must occur after devm_memremap_pages_release(). * * 4/ res is expected to be 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 dev_pagemap *pgmap){	resource_size_t align_start, align_size, align_end;	struct vmem_altmap *altmap = pgmap->altmap_valid ?			&pgmap->altmap : NULL;	struct resource *res = &pgmap->res;	unsigned long pfn, pgoff, order;	pgprot_t pgprot = PAGE_KERNEL;	int error, nid, is_ram; 	align_start = res->start & ~(SECTION_SIZE - 1);	align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)		- align_start;	is_ram = region_intersects(align_start, align_size,		IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE); 	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); 	if (!pgmap->ref)		return ERR_PTR(-EINVAL); 	pgmap->dev = dev; 	mutex_lock(&pgmap_lock);	error = 0;	align_end = align_start + align_size - 1; 	foreach_order_pgoff(res, order, pgoff) {		error = __radix_tree_insert(&pgmap_radix,				PHYS_PFN(res->start) + pgoff, order, pgmap);		if (error) {			dev_err(dev, "%s: failed: %d\n", __func__, error);			break;		}	}	mutex_unlock(&pgmap_lock);	if (error)		goto err_radix; 	nid = dev_to_node(dev);	if (nid < 0)		nid = numa_mem_id(); 	error = track_pfn_remap(NULL, &pgprot, PHYS_PFN(align_start), 0,			align_size);	if (error)		goto err_pfn_remap; 	mem_hotplug_begin();	error = arch_add_memory(nid, align_start, align_size, altmap, false);	if (!error)		move_pfn_range_to_zone(&NODE_DATA(nid)->node_zones[ZONE_DEVICE],					align_start >> PAGE_SHIFT,					align_size >> PAGE_SHIFT, altmap);	mem_hotplug_done();	if (error)		goto err_add_memory; 	for_each_device_pfn(pfn, pgmap) {		struct page *page = pfn_to_page(pfn); 		/*		 * ZONE_DEVICE pages union ->lru with a ->pgmap back		 * pointer.  It is a bug if a ZONE_DEVICE page is ever		 * freed or placed on a driver-private list.  Seed the		 * storage with LIST_POISON* values.		 */		list_del(&page->lru);		page->pgmap = pgmap;		percpu_ref_get(pgmap->ref);	} 	devm_add_action(dev, devm_memremap_pages_release, pgmap); 	return __va(res->start);  err_add_memory:	untrack_pfn(NULL, PHYS_PFN(align_start), align_size); err_pfn_remap: err_radix:	pgmap_radix_release(res, pgoff);	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;} /** * get_dev_pagemap() - take a new live reference on the dev_pagemap for @pfn * @pfn: page frame number to lookup page_map * @pgmap: optional known pgmap that already has a reference * * If @pgmap is non-NULL and covers @pfn it will be returned as-is.  If @pgmap * is non-NULL but does not cover @pfn the reference to it will be released. */struct dev_pagemap *get_dev_pagemap(unsigned long pfn,		struct dev_pagemap *pgmap){	resource_size_t phys = PFN_PHYS(pfn); 	/*	 * In the cached case we're already holding a live reference.	 */	if (pgmap) {		if (phys >= pgmap->res.start && phys <= pgmap->res.end)			return pgmap;		put_dev_pagemap(pgmap);	} 	/* fall back to slow path lookup */	rcu_read_lock();	pgmap = radix_tree_lookup(&pgmap_radix, PHYS_PFN(phys));	if (pgmap && !percpu_ref_tryget_live(pgmap->ref))		pgmap = NULL;	rcu_read_unlock(); 	return pgmap;}#endif /* CONFIG_ZONE_DEVICE */ #if IS_ENABLED(CONFIG_DEVICE_PRIVATE) ||  IS_ENABLED(CONFIG_DEVICE_PUBLIC)void put_zone_device_private_or_public_page(struct page *page){	int count = page_ref_dec_return(page); 	/*	 * If refcount is 1 then page is freed and refcount is stable as nobody	 * holds a reference on the page.	 */	if (count == 1) {		/* Clear Active bit in case of parallel mark_page_accessed */		__ClearPageActive(page);		__ClearPageWaiters(page); 		page->mapping = NULL;		mem_cgroup_uncharge(page); 		page->pgmap->page_free(page, page->pgmap->data);	} else if (!count)		__put_page(page);}EXPORT_SYMBOL(put_zone_device_private_or_public_page);#endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */