diff options
Diffstat (limited to 'kernel/memremap.c')
| -rw-r--r-- | kernel/memremap.c | 210 |
1 files changed, 30 insertions, 180 deletions
diff --git a/kernel/memremap.c b/kernel/memremap.c index 895e6b76b25e..5857267a4af5 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -1,15 +1,5 @@ -/* - * 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. - */ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright(c) 2015 Intel Corporation. All rights reserved. */ #include <linux/radix-tree.h> #include <linux/device.h> #include <linux/types.h> @@ -19,170 +9,8 @@ #include <linux/memory_hotplug.h> #include <linux/swap.h> #include <linux/swapops.h> +#include <linux/wait_bit.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_wb -static void *arch_memremap_wb(resource_size_t offset, unsigned long size) -{ - return (__force void *)ioremap_cache(offset, size); -} -#endif - -#ifndef arch_memremap_can_ram_remap -static 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_DEVICE static DEFINE_MUTEX(pgmap_lock); static RADIX_TREE(pgmap_radix, GFP_KERNEL); #define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1) @@ -473,10 +301,32 @@ struct dev_pagemap *get_dev_pagemap(unsigned long pfn, return pgmap; } -#endif /* CONFIG_ZONE_DEVICE */ +EXPORT_SYMBOL_GPL(get_dev_pagemap); + +#ifdef CONFIG_DEV_PAGEMAP_OPS +DEFINE_STATIC_KEY_FALSE(devmap_managed_key); +EXPORT_SYMBOL_GPL(devmap_managed_key); +static atomic_t devmap_enable; + +/* + * Toggle the static key for ->page_free() callbacks when dev_pagemap + * pages go idle. + */ +void dev_pagemap_get_ops(void) +{ + if (atomic_inc_return(&devmap_enable) == 1) + static_branch_enable(&devmap_managed_key); +} +EXPORT_SYMBOL_GPL(dev_pagemap_get_ops); + +void dev_pagemap_put_ops(void) +{ + if (atomic_dec_and_test(&devmap_enable)) + static_branch_disable(&devmap_managed_key); +} +EXPORT_SYMBOL_GPL(dev_pagemap_put_ops); -#if IS_ENABLED(CONFIG_DEVICE_PRIVATE) || IS_ENABLED(CONFIG_DEVICE_PUBLIC) -void put_zone_device_private_or_public_page(struct page *page) +void __put_devmap_managed_page(struct page *page) { int count = page_ref_dec_return(page); @@ -496,5 +346,5 @@ void put_zone_device_private_or_public_page(struct page *page) } else if (!count) __put_page(page); } -EXPORT_SYMBOL(put_zone_device_private_or_public_page); -#endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */ +EXPORT_SYMBOL_GPL(__put_devmap_managed_page); +#endif /* CONFIG_DEV_PAGEMAP_OPS */ |