Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1c29f25b authored by Toshi Kani's avatar Toshi Kani Committed by Ingo Molnar
Browse files

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: default avatarToshi Kani <toshi.kani@hpe.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Acked-by: default avatarDan 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: default avatarIngo Molnar <mingo@kernel.org>
parent 05fee7cf

include/linux/mm.h

+2 −1
Original line number Diff line number Diff line
@@ -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);

kernel/memremap.c

+7 −6
Original line number Diff line number Diff line
@@ -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;

kernel/resource.c

+15 −11
Original line number Diff line number Diff line
@@ -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)

{