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authorAlistair Popple <apopple@nvidia.com>2021-05-07 04:05:24 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-05-07 10:26:33 +0300
commitd486ccb2522fc22f04f191cac99a844f92d56a7e (patch)
treee20f053849d01c6489aa33f0cee4c907260a2f4c
parent97523a4edb7b9dc2be48a24a2387fb1328b29521 (diff)
downloadlinux-d486ccb2522fc22f04f191cac99a844f92d56a7e.tar.xz
kernel/resource: allow region_intersects users to hold resource_lock
Introduce a version of region_intersects() that can be called with the resource_lock already held. This will be used in a future fix to __request_free_mem_region(). [akpm@linux-foundation.org: make __region_intersects static] Link: https://lkml.kernel.org/r/20210419070109.4780-1-apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Muchun Song <smuchun@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--kernel/resource.c52
1 files changed, 31 insertions, 21 deletions
diff --git a/kernel/resource.c b/kernel/resource.c
index 7e00239a023a..f4aeeda7ee28 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -502,6 +502,34 @@ int __weak page_is_ram(unsigned long pfn)
}
EXPORT_SYMBOL_GPL(page_is_ram);
+static int __region_intersects(resource_size_t start, size_t size,
+ unsigned long flags, unsigned long desc)
+{
+ struct resource res;
+ int type = 0; int other = 0;
+ struct resource *p;
+
+ res.start = start;
+ res.end = start + size - 1;
+
+ for (p = iomem_resource.child; p ; p = p->sibling) {
+ bool is_type = (((p->flags & flags) == flags) &&
+ ((desc == IORES_DESC_NONE) ||
+ (desc == p->desc)));
+
+ if (resource_overlaps(p, &res))
+ is_type ? type++ : other++;
+ }
+
+ if (type == 0)
+ return REGION_DISJOINT;
+
+ if (other == 0)
+ return REGION_INTERSECTS;
+
+ return REGION_MIXED;
+}
+
/**
* region_intersects() - determine intersection of region with known resources
* @start: region start address
@@ -525,31 +553,13 @@ EXPORT_SYMBOL_GPL(page_is_ram);
int region_intersects(resource_size_t start, size_t size, unsigned long flags,
unsigned long desc)
{
- struct resource res;
- int type = 0; int other = 0;
- struct resource *p;
-
- res.start = start;
- res.end = start + size - 1;
+ int ret;
read_lock(&resource_lock);
- for (p = iomem_resource.child; p ; p = p->sibling) {
- bool is_type = (((p->flags & flags) == flags) &&
- ((desc == IORES_DESC_NONE) ||
- (desc == p->desc)));
-
- if (resource_overlaps(p, &res))
- is_type ? type++ : other++;
- }
+ ret = __region_intersects(start, size, flags, desc);
read_unlock(&resource_lock);
- if (type == 0)
- return REGION_DISJOINT;
-
- if (other == 0)
- return REGION_INTERSECTS;
-
- return REGION_MIXED;
+ return ret;
}
EXPORT_SYMBOL_GPL(region_intersects);