region_intersects() checks if a specified region partially overlaps
or fully eclipses a resource identified by @name. It currently sets
resource flags statically, which prevents the caller from specifying
a non-RAM region, such as persistent memory. Add @flags so that
any region can be specified to the function.
A helper function, region_intersects_ram(), is added so that the
callers that check a RAM region do not have to specify its iomem
resource name and flags. This interface is exported for modules,
such as the EINJ driver.
Signed-off-by: Toshi Kani <toshi.kani@xxxxxxx>
Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
---
include/linux/mm.h | 4 +++-
kernel/memremap.c | 5 ++---
kernel/resource.c | 23 ++++++++++++++++-------
3 files changed, 21 insertions(+), 11 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 00bad77..c776af3 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -362,7 +362,9 @@ 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, const char *type,
+ unsigned long flags);
+int region_intersects_ram(resource_size_t offset, size_t size);
/* 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..98f52f1 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -57,7 +57,7 @@ static void *try_ram_remap(resource_size_t offset, size_t size)
*/
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_ram(offset, size);
void *addr = NULL;
if (is_ram == REGION_MIXED) {
@@ -162,8 +162,7 @@ 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");
+ int is_ram = region_intersects_ram(res->start, resource_size(res));
struct page_map *page_map;
int error, nid;
diff --git a/kernel/resource.c b/kernel/resource.c
index f150dbb..15c133e 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -497,6 +497,7 @@ EXPORT_SYMBOL_GPL(page_is_ram);
* @start: region start address
* @size: size of region
* @name: name of resource (in iomem_resource)
+ * @flags: flags of resource (in iomem_resource)
*
* Check if the specified region partially overlaps or fully eclipses a
* resource identified by @name. Return REGION_DISJOINT if the region
@@ -504,15 +505,11 @@ EXPORT_SYMBOL_GPL(page_is_ram);
* @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.
- *
- * 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.
+ * region overlaps with undefined memory holes.
*/
-int region_intersects(resource_size_t start, size_t size, const char *name)
+int region_intersects(resource_size_t start, size_t size, const char *name,
+ unsigned long flags)
{
- unsigned long flags = IORESOURCE_MEM | IORESOURCE_BUSY;
resource_size_t end = start + size - 1;
int type = 0; int other = 0;
struct resource *p;
@@ -539,6 +536,18 @@ int region_intersects(resource_size_t start, size_t size, const char *name)
return REGION_DISJOINT;
}
+/*
+ * region_intersect_ram() 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_ram(resource_size_t start, size_t size)
+{
+ return region_intersects(start, size, "System RAM",
+ IORESOURCE_MEM | IORESOURCE_BUSY);
+}
+EXPORT_SYMBOL_GPL(region_intersects_ram);
+
void __weak arch_remove_reservations(struct resource *avail)
{
}
--
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