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memremap: Change region_intersects() to take @flags and @desc 

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 <toshi.kani@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jakub Sitnicki <jsitnicki@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm <linux-mm@kvack.org>
Link: http://lkml.kernel.org/r/1453841853-11383-13-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Toshi Kani 2016-01-26 21:57:28 +01:00 committed by Ingo Molnar
parent 05fee7cfab
commit 1c29f25bf5
3 changed files with 24 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
include/linux/mm.h
View File

@ -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);

13
kernel/memremap.c
View File

@ -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;

26
kernel/resource.c
View File

@ -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)
{