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authorAlistair Popple2021-05-06 18:05:27 -0700
committerLinus Torvalds2021-05-07 00:26:33 -0700
commit63cdafe0af982e7da9ded37ccf21109a02bc6832 (patch)
tree345c569c16a183b27f7014f91ea40b94f6dedbbe
parentd486ccb2522fc22f04f191cac99a844f92d56a7e (diff)
kernel/resource: refactor __request_region to allow external locking
Refactor the portion of __request_region() done whilst holding the resource_lock into a separate function to allow callers to hold the lock. Link: https://lkml.kernel.org/r/20210419070109.4780-2-apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.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, 32 insertions, 20 deletions
diff --git a/kernel/resource.c b/kernel/resource.c
index f4aeeda7ee28..c8e473b68f17 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -1160,31 +1160,16 @@ struct address_space *iomem_get_mapping(void)
return smp_load_acquire(&iomem_inode)->i_mapping;
}
-/**
- * __request_region - create a new busy resource region
- * @parent: parent resource descriptor
- * @start: resource start address
- * @n: resource region size
- * @name: reserving caller's ID string
- * @flags: IO resource flags
- */
-struct resource * __request_region(struct resource *parent,
+static int __request_region_locked(struct resource *res, struct resource *parent,
resource_size_t start, resource_size_t n,
const char *name, int flags)
{
DECLARE_WAITQUEUE(wait, current);
- struct resource *res = alloc_resource(GFP_KERNEL);
- struct resource *orig_parent = parent;
-
- if (!res)
- return NULL;
res->name = name;
res->start = start;
res->end = start + n - 1;
- write_lock(&resource_lock);
-
for (;;) {
struct resource *conflict;
@@ -1220,13 +1205,40 @@ struct resource * __request_region(struct resource *parent,
continue;
}
/* Uhhuh, that didn't work out.. */
- free_resource(res);
- res = NULL;
- break;
+ return -EBUSY;
}
+
+ return 0;
+}
+
+/**
+ * __request_region - create a new busy resource region
+ * @parent: parent resource descriptor
+ * @start: resource start address
+ * @n: resource region size
+ * @name: reserving caller's ID string
+ * @flags: IO resource flags
+ */
+struct resource *__request_region(struct resource *parent,
+ resource_size_t start, resource_size_t n,
+ const char *name, int flags)
+{
+ struct resource *res = alloc_resource(GFP_KERNEL);
+ int ret;
+
+ if (!res)
+ return NULL;
+
+ write_lock(&resource_lock);
+ ret = __request_region_locked(res, parent, start, n, name, flags);
write_unlock(&resource_lock);
- if (res && orig_parent == &iomem_resource)
+ if (ret) {
+ free_resource(res);
+ return NULL;
+ }
+
+ if (parent == &iomem_resource)
revoke_iomem(res);
return res;