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authorBjorn Helgaas <bjorn.helgaas@hp.com>2010-12-16 10:38:46 -0700
committerJesse Barnes <jbarnes@virtuousgeek.org>2010-12-17 10:01:09 -0800
commitfcb119183c73bf0781009713f303e28b1fb13d3e (patch)
tree94d739189963cecafae1b497845eb1e856558e49
parentc0f5ac5426f7fd82b23dd5c6a1e633b290294a08 (diff)
resources: add arch hook for preventing allocation in reserved areas
This adds arch_remove_reservations(), which an arch can implement if it needs to protect part of the address space from allocation. Sometimes that can be done by just putting a region in the resource tree, but there are cases where that doesn't work well. For example, x86 BIOS E820 reservations are not related to devices, so they may overlap part of, all of, or more than a device resource, so they may not end up at the correct spot in the resource tree. Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
-rw-r--r--include/linux/ioport.h1
-rw-r--r--kernel/resource.c6
2 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index b22790268b64..e9bb22cba764 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -123,6 +123,7 @@ extern void reserve_region_with_split(struct resource *root,
extern struct resource *insert_resource_conflict(struct resource *parent, struct resource *new);
extern int insert_resource(struct resource *parent, struct resource *new);
extern void insert_resource_expand_to_fit(struct resource *root, struct resource *new);
+extern void arch_remove_reservations(struct resource *avail);
extern int allocate_resource(struct resource *root, struct resource *new,
resource_size_t size, resource_size_t min,
resource_size_t max, resource_size_t align,
diff --git a/kernel/resource.c b/kernel/resource.c
index 560659f7baef..798e2fae2a06 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -357,6 +357,10 @@ int __weak page_is_ram(unsigned long pfn)
return walk_system_ram_range(pfn, 1, NULL, __is_ram) == 1;
}
+void __weak arch_remove_reservations(struct resource *avail)
+{
+}
+
static resource_size_t simple_align_resource(void *data,
const struct resource *avail,
resource_size_t size,
@@ -394,6 +398,7 @@ static int find_resource(struct resource *root, struct resource *new,
struct resource *this = root->child;
struct resource tmp = *new, avail, alloc;
+ tmp.flags = new->flags;
tmp.start = root->start;
/*
* Skip past an allocated resource that starts at 0, since the assignment
@@ -410,6 +415,7 @@ static int find_resource(struct resource *root, struct resource *new,
tmp.end = root->end;
resource_clip(&tmp, min, max);
+ arch_remove_reservations(&tmp);
/* Check for overflow after ALIGN() */
avail = *new;