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Date: Mon, 14 Dec 2015 16:37:23 -0700
From: Toshi Kani <toshi.kani@....com>
To: akpm@...ux-foundation.org, bp@...en8.de
Cc: linux-arch@...r.kernel.org, linux-mm@...ck.org,
linux-kernel@...r.kernel.org,
Dan Williams <dan.j.williams@...el.com>,
Toshi Kani <toshi.kani@....com>
Subject: [PATCH 08/11] memremap: Change region_intersects() to use System RAM type
Change region_intersects() to add @flags, and make @name optinal
with NULL. When NULL is set to @name, it skips strcmp().
Change the callers of region_intersects(), memremap() and
devm_memremap(), to set IORESOURCE_SYSTEM_RAM to @flags for
searching System RAM.
Also, export region_intersects() so that the EINJ driver can
call this function in a later patch.
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Dan Williams <dan.j.williams@...el.com>
Signed-off-by: Toshi Kani <toshi.kani@....com>
---
include/linux/mm.h | 3 ++-
kernel/memremap.c | 13 +++++++------
kernel/resource.c | 25 ++++++++++++++-----------
3 files changed, 23 insertions(+), 18 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 00bad77..d2ee94a 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -362,7 +362,8 @@ 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,
+ const char *name);
/* Support for virtually mapped pages */
struct page *vmalloc_to_page(const void *addr);
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 7658d32..cefd382 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -44,7 +44,7 @@ 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
@@ -53,11 +53,12 @@ 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, NULL);
void *addr = NULL;
if (is_ram == REGION_MIXED) {
@@ -73,7 +74,7 @@ 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);
@@ -85,7 +86,7 @@ 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",
@@ -163,7 +164,7 @@ static void devm_memremap_pages_release(struct device *dev, void *res)
void *devm_memremap_pages(struct device *dev, struct resource *res)
{
int is_ram = region_intersects(res->start, resource_size(res),
- "System RAM");
+ IORESOURCE_SYSTEM_RAM, NULL);
struct page_map *page_map;
int error, nid;
diff --git a/kernel/resource.c b/kernel/resource.c
index d30a175..56bed6d 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -496,31 +496,33 @@ 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)
+ * @name: name of resource (in iomem_resource) or NULL
*
* 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 @name (optinal with NULL). Return
+ * REGION_DISJOINT if the region does not overlap @flags/@...e, return
+ * REGION_MIXED if the region overlaps @flags/@...e and another resource,
+ * and return REGION_INTERSECTS if the region overlaps @flags/@...e 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,
+ const char *name)
{
- 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) &&
+ (!name || strcmp(p->name, name) == 0);
if (start >= p->start && start <= p->end)
is_type ? type++ : other++;
@@ -539,6 +541,7 @@ 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)
{
--
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