From mboxrd@z Thu Jan 1 00:00:00 1970 From: Borislav Petkov Subject: [PATCH 12/17] memremap: Change region_intersects() to take @flags and @desc Date: Tue, 26 Jan 2016 21:57:28 +0100 Message-ID: <1453841853-11383-13-git-send-email-bp@alien8.de> References: <1453841853-11383-1-git-send-email-bp@alien8.de> Return-path: In-Reply-To: <1453841853-11383-1-git-send-email-bp@alien8.de> Sender: linux-arch-owner@vger.kernel.org To: Ingo Molnar Cc: LKML , Andrew Morton , Ard Biesheuvel , Dan Williams , Jakub Sitnicki , Jan Kara , Jiang Liu , Kees Cook , "Kirill A. Shutemov" , Konstantin Khlebnikov , linux-arch@vger.kernel.org, linux-mm , Michal Hocko , Naoya Horiguchi , Tejun Heo , Vlastimil Babka List-Id: linux-mm.kvack.org From: Toshi Kani Change region_intersects() to identify a target with @flags and @desc, instead of @name with strcmp(). Change the callers of region_intersects(), memremap() and devm_memremap(), to set IORESOURCE_SYSTEM_RAM in @flags and IORES_DESC_NONE in @desc when searching System RAM. Also, export region_intersects() so that the ACPI EINJ error injection driver can call this function in a later patch. Signed-off-by: Toshi Kani Cc: Andrew Morton Cc: Ard Biesheuvel Cc: Dan Williams Cc: Jakub Sitnicki Cc: Jan Kara Cc: Jiang Liu Cc: Kees Cook Cc: "Kirill A. Shutemov" Cc: Konstantin Khlebnikov Cc: linux-arch@vger.kernel.org Cc: linux-mm Cc: Michal Hocko Cc: Naoya Horiguchi Cc: Tejun Heo Cc: Vlastimil Babka Link: http://lkml.kernel.org/r/1452020081-26534-12-git-send-email-toshi.kani@hpe.com Signed-off-by: Borislav Petkov --- include/linux/mm.h | 3 ++- kernel/memremap.c | 13 +++++++------ kernel/resource.c | 26 +++++++++++++++----------- 3 files changed, 24 insertions(+), 18 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index f1cd22f2df1a..cd5a300d3397 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -385,7 +385,8 @@ enum { REGION_MIXED, }; -int region_intersects(resource_size_t offset, size_t size, const char *type); +int region_intersects(resource_size_t offset, size_t size, unsigned long flags, + unsigned long desc); /* Support for virtually mapped pages */ struct page *vmalloc_to_page(const void *addr); diff --git a/kernel/memremap.c b/kernel/memremap.c index e517a16cb426..293309cac061 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -47,7 +47,7 @@ static void *try_ram_remap(resource_size_t offset, size_t size) * 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 + * 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 @@ -56,11 +56,12 @@ static void *try_ram_remap(resource_size_t offset, size_t size) * 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. + * 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"); + int is_ram = region_intersects(offset, size, + IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE); void *addr = NULL; if (is_ram == REGION_MIXED) { @@ -76,7 +77,7 @@ void *memremap(resource_size_t offset, size_t size, unsigned long flags) * 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" + * the requested range is potentially in System RAM. */ if (is_ram == REGION_INTERSECTS) addr = try_ram_remap(offset, size); @@ -88,7 +89,7 @@ void *memremap(resource_size_t offset, size_t size, unsigned long flags) * 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" + * System RAM. */ if (!addr && is_ram == REGION_INTERSECTS && flags) { WARN_ONCE(1, "memremap attempted on ram %pa size: %#lx\n", @@ -266,7 +267,7 @@ void *devm_memremap_pages(struct device *dev, struct resource *res, struct percpu_ref *ref, struct vmem_altmap *altmap) { int is_ram = region_intersects(res->start, resource_size(res), - "System RAM"); + IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE); resource_size_t key, align_start, align_size; struct dev_pagemap *pgmap; struct page_map *page_map; diff --git a/kernel/resource.c b/kernel/resource.c index 994f1e41269b..0041cedc47d6 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -496,31 +496,34 @@ EXPORT_SYMBOL_GPL(page_is_ram); * region_intersects() - determine intersection of region with known resources * @start: region start address * @size: size of region - * @name: name of resource (in iomem_resource) + * @flags: flags of resource (in iomem_resource) + * @desc: descriptor of resource (in iomem_resource) or IORES_DESC_NONE * * Check if the specified region partially overlaps or fully eclipses a - * resource identified by @name. Return REGION_DISJOINT if the region - * does not overlap @name, return REGION_MIXED if the region overlaps - * @type and another resource, and return REGION_INTERSECTS if the - * region overlaps @type and no other defined resource. Note, that - * REGION_INTERSECTS is also returned in the case when the specified - * region overlaps RAM and undefined memory holes. + * resource identified by @flags and @desc (optional with IORES_DESC_NONE). + * Return REGION_DISJOINT if the region does not overlap @flags/@desc, + * return REGION_MIXED if the region overlaps @flags/@desc and another + * resource, and return REGION_INTERSECTS if the region overlaps @flags/@desc + * and no other defined resource. Note that REGION_INTERSECTS is also + * returned in the case when the specified region overlaps RAM and undefined + * memory holes. * * region_intersect() is used by memory remapping functions to ensure * the user is not remapping RAM and is a vast speed up over walking * through the resource table page by page. */ -int region_intersects(resource_size_t start, size_t size, const char *name) +int region_intersects(resource_size_t start, size_t size, unsigned long flags, + unsigned long desc) { - unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY; resource_size_t end = start + size - 1; int type = 0; int other = 0; struct resource *p; read_lock(&resource_lock); for (p = iomem_resource.child; p ; p = p->sibling) { - bool is_type = strcmp(p->name, name) == 0 && - ((p->flags & flags) == flags); + bool is_type = (((p->flags & flags) == flags) && + ((desc == IORES_DESC_NONE) || + (desc == p->desc))); if (start >= p->start && start <= p->end) is_type ? type++ : other++; @@ -539,6 +542,7 @@ int region_intersects(resource_size_t start, size_t size, const char *name) return REGION_DISJOINT; } +EXPORT_SYMBOL_GPL(region_intersects); void __weak arch_remove_reservations(struct resource *avail) { -- 2.3.5