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436 lines
12 KiB
436 lines
12 KiB
/* |
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* Copyright(c) 2015 Intel Corporation. All rights reserved. |
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* |
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* This program is free software; you can redistribute it and/or modify |
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* it under the terms of version 2 of the GNU General Public License as |
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* published by the Free Software Foundation. |
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* |
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* This program is distributed in the hope that it will be useful, but |
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* WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* General Public License for more details. |
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*/ |
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#include <linux/radix-tree.h> |
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#include <linux/memremap.h> |
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#include <linux/device.h> |
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#include <linux/types.h> |
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#include <linux/pfn_t.h> |
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#include <linux/io.h> |
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#include <linux/mm.h> |
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#include <linux/memory_hotplug.h> |
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#ifndef ioremap_cache |
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/* temporary while we convert existing ioremap_cache users to memremap */ |
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__weak void __iomem *ioremap_cache(resource_size_t offset, unsigned long size) |
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{ |
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return ioremap(offset, size); |
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} |
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#endif |
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#ifndef arch_memremap_wb |
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static void *arch_memremap_wb(resource_size_t offset, unsigned long size) |
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{ |
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return (__force void *)ioremap_cache(offset, size); |
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} |
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#endif |
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static void *try_ram_remap(resource_size_t offset, size_t size) |
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{ |
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unsigned long pfn = PHYS_PFN(offset); |
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|
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/* In the simple case just return the existing linear address */ |
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if (pfn_valid(pfn) && !PageHighMem(pfn_to_page(pfn))) |
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return __va(offset); |
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return NULL; /* fallback to arch_memremap_wb */ |
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} |
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/** |
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* memremap() - remap an iomem_resource as cacheable memory |
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* @offset: iomem resource start address |
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* @size: size of remap |
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* @flags: any of MEMREMAP_WB, MEMREMAP_WT and MEMREMAP_WC |
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* |
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* memremap() is "ioremap" for cases where it is known that the resource |
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* being mapped does not have i/o side effects and the __iomem |
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* annotation is not applicable. In the case of multiple flags, the different |
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* mapping types will be attempted in the order listed below until one of |
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* them succeeds. |
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* |
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* MEMREMAP_WB - matches the default mapping for System RAM on |
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* the architecture. This is usually a read-allocate write-back cache. |
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* Morever, if MEMREMAP_WB is specified and the requested remap region is RAM |
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* memremap() will bypass establishing a new mapping and instead return |
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* a pointer into the direct map. |
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* |
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* MEMREMAP_WT - establish a mapping whereby writes either bypass the |
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* cache or are written through to memory and never exist in a |
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* cache-dirty state with respect to program visibility. Attempts to |
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* map System RAM with this mapping type will fail. |
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* |
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* MEMREMAP_WC - establish a writecombine mapping, whereby writes may |
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* be coalesced together (e.g. in the CPU's write buffers), but is otherwise |
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* uncached. Attempts to map System RAM with this mapping type will fail. |
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*/ |
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void *memremap(resource_size_t offset, size_t size, unsigned long flags) |
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{ |
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int is_ram = region_intersects(offset, size, |
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IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE); |
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void *addr = NULL; |
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if (!flags) |
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return NULL; |
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if (is_ram == REGION_MIXED) { |
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WARN_ONCE(1, "memremap attempted on mixed range %pa size: %#lx\n", |
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&offset, (unsigned long) size); |
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return NULL; |
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} |
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|
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/* Try all mapping types requested until one returns non-NULL */ |
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if (flags & MEMREMAP_WB) { |
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/* |
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* MEMREMAP_WB is special in that it can be satisifed |
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* from the direct map. Some archs depend on the |
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* capability of memremap() to autodetect cases where |
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* the requested range is potentially in System RAM. |
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*/ |
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if (is_ram == REGION_INTERSECTS) |
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addr = try_ram_remap(offset, size); |
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if (!addr) |
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addr = arch_memremap_wb(offset, size); |
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} |
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/* |
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* If we don't have a mapping yet and other request flags are |
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* present then we will be attempting to establish a new virtual |
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* address mapping. Enforce that this mapping is not aliasing |
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* System RAM. |
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*/ |
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if (!addr && is_ram == REGION_INTERSECTS && flags != MEMREMAP_WB) { |
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WARN_ONCE(1, "memremap attempted on ram %pa size: %#lx\n", |
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&offset, (unsigned long) size); |
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return NULL; |
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} |
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if (!addr && (flags & MEMREMAP_WT)) |
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addr = ioremap_wt(offset, size); |
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if (!addr && (flags & MEMREMAP_WC)) |
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addr = ioremap_wc(offset, size); |
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return addr; |
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} |
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EXPORT_SYMBOL(memremap); |
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void memunmap(void *addr) |
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{ |
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if (is_vmalloc_addr(addr)) |
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iounmap((void __iomem *) addr); |
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} |
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EXPORT_SYMBOL(memunmap); |
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static void devm_memremap_release(struct device *dev, void *res) |
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{ |
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memunmap(*(void **)res); |
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} |
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static int devm_memremap_match(struct device *dev, void *res, void *match_data) |
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{ |
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return *(void **)res == match_data; |
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} |
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void *devm_memremap(struct device *dev, resource_size_t offset, |
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size_t size, unsigned long flags) |
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{ |
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void **ptr, *addr; |
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ptr = devres_alloc_node(devm_memremap_release, sizeof(*ptr), GFP_KERNEL, |
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dev_to_node(dev)); |
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if (!ptr) |
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return ERR_PTR(-ENOMEM); |
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addr = memremap(offset, size, flags); |
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if (addr) { |
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*ptr = addr; |
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devres_add(dev, ptr); |
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} else { |
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devres_free(ptr); |
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return ERR_PTR(-ENXIO); |
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} |
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return addr; |
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} |
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EXPORT_SYMBOL(devm_memremap); |
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void devm_memunmap(struct device *dev, void *addr) |
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{ |
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WARN_ON(devres_release(dev, devm_memremap_release, |
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devm_memremap_match, addr)); |
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} |
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EXPORT_SYMBOL(devm_memunmap); |
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#ifdef CONFIG_ZONE_DEVICE |
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static DEFINE_MUTEX(pgmap_lock); |
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static RADIX_TREE(pgmap_radix, GFP_KERNEL); |
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#define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1) |
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#define SECTION_SIZE (1UL << PA_SECTION_SHIFT) |
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struct page_map { |
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struct resource res; |
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struct percpu_ref *ref; |
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struct dev_pagemap pgmap; |
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struct vmem_altmap altmap; |
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}; |
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void get_zone_device_page(struct page *page) |
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{ |
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percpu_ref_get(page->pgmap->ref); |
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} |
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EXPORT_SYMBOL(get_zone_device_page); |
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void put_zone_device_page(struct page *page) |
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{ |
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put_dev_pagemap(page->pgmap); |
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} |
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EXPORT_SYMBOL(put_zone_device_page); |
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static void pgmap_radix_release(struct resource *res) |
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{ |
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resource_size_t key, align_start, align_size, align_end; |
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align_start = res->start & ~(SECTION_SIZE - 1); |
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align_size = ALIGN(resource_size(res), SECTION_SIZE); |
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align_end = align_start + align_size - 1; |
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mutex_lock(&pgmap_lock); |
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for (key = res->start; key <= res->end; key += SECTION_SIZE) |
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radix_tree_delete(&pgmap_radix, key >> PA_SECTION_SHIFT); |
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mutex_unlock(&pgmap_lock); |
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} |
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static unsigned long pfn_first(struct page_map *page_map) |
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{ |
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struct dev_pagemap *pgmap = &page_map->pgmap; |
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const struct resource *res = &page_map->res; |
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struct vmem_altmap *altmap = pgmap->altmap; |
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unsigned long pfn; |
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pfn = res->start >> PAGE_SHIFT; |
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if (altmap) |
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pfn += vmem_altmap_offset(altmap); |
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return pfn; |
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} |
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static unsigned long pfn_end(struct page_map *page_map) |
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{ |
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const struct resource *res = &page_map->res; |
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return (res->start + resource_size(res)) >> PAGE_SHIFT; |
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} |
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#define for_each_device_pfn(pfn, map) \ |
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for (pfn = pfn_first(map); pfn < pfn_end(map); pfn++) |
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static void devm_memremap_pages_release(struct device *dev, void *data) |
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{ |
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struct page_map *page_map = data; |
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struct resource *res = &page_map->res; |
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resource_size_t align_start, align_size; |
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struct dev_pagemap *pgmap = &page_map->pgmap; |
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if (percpu_ref_tryget_live(pgmap->ref)) { |
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dev_WARN(dev, "%s: page mapping is still live!\n", __func__); |
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percpu_ref_put(pgmap->ref); |
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} |
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/* pages are dead and unused, undo the arch mapping */ |
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align_start = res->start & ~(SECTION_SIZE - 1); |
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align_size = ALIGN(resource_size(res), SECTION_SIZE); |
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lock_device_hotplug(); |
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mem_hotplug_begin(); |
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arch_remove_memory(align_start, align_size); |
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mem_hotplug_done(); |
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unlock_device_hotplug(); |
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untrack_pfn(NULL, PHYS_PFN(align_start), align_size); |
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pgmap_radix_release(res); |
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dev_WARN_ONCE(dev, pgmap->altmap && pgmap->altmap->alloc, |
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"%s: failed to free all reserved pages\n", __func__); |
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} |
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/* assumes rcu_read_lock() held at entry */ |
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struct dev_pagemap *find_dev_pagemap(resource_size_t phys) |
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{ |
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struct page_map *page_map; |
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WARN_ON_ONCE(!rcu_read_lock_held()); |
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page_map = radix_tree_lookup(&pgmap_radix, phys >> PA_SECTION_SHIFT); |
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return page_map ? &page_map->pgmap : NULL; |
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} |
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/** |
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* devm_memremap_pages - remap and provide memmap backing for the given resource |
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* @dev: hosting device for @res |
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* @res: "host memory" address range |
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* @ref: a live per-cpu reference count |
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* @altmap: optional descriptor for allocating the memmap from @res |
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* |
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* Notes: |
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* 1/ @ref must be 'live' on entry and 'dead' before devm_memunmap_pages() time |
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* (or devm release event). |
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* |
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* 2/ @res is expected to be a host memory range that could feasibly be |
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* treated as a "System RAM" range, i.e. not a device mmio range, but |
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* this is not enforced. |
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*/ |
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void *devm_memremap_pages(struct device *dev, struct resource *res, |
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struct percpu_ref *ref, struct vmem_altmap *altmap) |
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{ |
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resource_size_t key, align_start, align_size, align_end; |
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pgprot_t pgprot = PAGE_KERNEL; |
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struct dev_pagemap *pgmap; |
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struct page_map *page_map; |
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int error, nid, is_ram; |
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unsigned long pfn; |
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align_start = res->start & ~(SECTION_SIZE - 1); |
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align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE) |
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- align_start; |
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is_ram = region_intersects(align_start, align_size, |
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IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE); |
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if (is_ram == REGION_MIXED) { |
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WARN_ONCE(1, "%s attempted on mixed region %pr\n", |
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__func__, res); |
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return ERR_PTR(-ENXIO); |
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} |
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if (is_ram == REGION_INTERSECTS) |
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return __va(res->start); |
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if (!ref) |
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return ERR_PTR(-EINVAL); |
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page_map = devres_alloc_node(devm_memremap_pages_release, |
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sizeof(*page_map), GFP_KERNEL, dev_to_node(dev)); |
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if (!page_map) |
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return ERR_PTR(-ENOMEM); |
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pgmap = &page_map->pgmap; |
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memcpy(&page_map->res, res, sizeof(*res)); |
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pgmap->dev = dev; |
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if (altmap) { |
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memcpy(&page_map->altmap, altmap, sizeof(*altmap)); |
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pgmap->altmap = &page_map->altmap; |
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} |
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pgmap->ref = ref; |
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pgmap->res = &page_map->res; |
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mutex_lock(&pgmap_lock); |
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error = 0; |
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align_end = align_start + align_size - 1; |
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for (key = align_start; key <= align_end; key += SECTION_SIZE) { |
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struct dev_pagemap *dup; |
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rcu_read_lock(); |
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dup = find_dev_pagemap(key); |
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rcu_read_unlock(); |
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if (dup) { |
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dev_err(dev, "%s: %pr collides with mapping for %s\n", |
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__func__, res, dev_name(dup->dev)); |
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error = -EBUSY; |
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break; |
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} |
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error = radix_tree_insert(&pgmap_radix, key >> PA_SECTION_SHIFT, |
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page_map); |
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if (error) { |
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dev_err(dev, "%s: failed: %d\n", __func__, error); |
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break; |
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} |
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} |
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mutex_unlock(&pgmap_lock); |
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if (error) |
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goto err_radix; |
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nid = dev_to_node(dev); |
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if (nid < 0) |
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nid = numa_mem_id(); |
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error = track_pfn_remap(NULL, &pgprot, PHYS_PFN(align_start), 0, |
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align_size); |
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if (error) |
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goto err_pfn_remap; |
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lock_device_hotplug(); |
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mem_hotplug_begin(); |
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error = arch_add_memory(nid, align_start, align_size, true); |
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mem_hotplug_done(); |
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unlock_device_hotplug(); |
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if (error) |
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goto err_add_memory; |
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for_each_device_pfn(pfn, page_map) { |
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struct page *page = pfn_to_page(pfn); |
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/* |
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* ZONE_DEVICE pages union ->lru with a ->pgmap back |
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* pointer. It is a bug if a ZONE_DEVICE page is ever |
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* freed or placed on a driver-private list. Seed the |
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* storage with LIST_POISON* values. |
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*/ |
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list_del(&page->lru); |
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page->pgmap = pgmap; |
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} |
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devres_add(dev, page_map); |
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return __va(res->start); |
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err_add_memory: |
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untrack_pfn(NULL, PHYS_PFN(align_start), align_size); |
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err_pfn_remap: |
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err_radix: |
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pgmap_radix_release(res); |
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devres_free(page_map); |
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return ERR_PTR(error); |
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} |
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EXPORT_SYMBOL(devm_memremap_pages); |
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unsigned long vmem_altmap_offset(struct vmem_altmap *altmap) |
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{ |
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/* number of pfns from base where pfn_to_page() is valid */ |
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return altmap->reserve + altmap->free; |
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} |
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void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns) |
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{ |
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altmap->alloc -= nr_pfns; |
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} |
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struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start) |
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{ |
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/* |
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* 'memmap_start' is the virtual address for the first "struct |
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* page" in this range of the vmemmap array. In the case of |
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* CONFIG_SPARSEMEM_VMEMMAP a page_to_pfn conversion is simple |
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* pointer arithmetic, so we can perform this to_vmem_altmap() |
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* conversion without concern for the initialization state of |
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* the struct page fields. |
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*/ |
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struct page *page = (struct page *) memmap_start; |
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struct dev_pagemap *pgmap; |
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/* |
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* Unconditionally retrieve a dev_pagemap associated with the |
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* given physical address, this is only for use in the |
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* arch_{add|remove}_memory() for setting up and tearing down |
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* the memmap. |
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*/ |
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rcu_read_lock(); |
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pgmap = find_dev_pagemap(__pfn_to_phys(page_to_pfn(page))); |
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rcu_read_unlock(); |
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return pgmap ? pgmap->altmap : NULL; |
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} |
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#endif /* CONFIG_ZONE_DEVICE */
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