summaryrefslogtreecommitdiffstats
path: root/kernel/resource.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/resource.c')
-rw-r--r--kernel/resource.c83
1 files changed, 72 insertions, 11 deletions
diff --git a/kernel/resource.c b/kernel/resource.c
index 9db38a1..6de60c1 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -193,6 +193,13 @@ static int __release_resource(struct resource *old)
return -EINVAL;
}
+/**
+ * request_resource - request and reserve an I/O or memory resource
+ * @root: root resource descriptor
+ * @new: resource descriptor desired by caller
+ *
+ * Returns 0 for success, negative error code on error.
+ */
int request_resource(struct resource *root, struct resource *new)
{
struct resource *conflict;
@@ -205,6 +212,15 @@ int request_resource(struct resource *root, struct resource *new)
EXPORT_SYMBOL(request_resource);
+/**
+ * ____request_resource - reserve a resource, with resource conflict returned
+ * @root: root resource descriptor
+ * @new: resource descriptor desired by caller
+ *
+ * Returns:
+ * On success, NULL is returned.
+ * On error, a pointer to the conflicting resource is returned.
+ */
struct resource *____request_resource(struct resource *root, struct resource *new)
{
struct resource *conflict;
@@ -217,6 +233,10 @@ struct resource *____request_resource(struct resource *root, struct resource *ne
EXPORT_SYMBOL(____request_resource);
+/**
+ * release_resource - release a previously reserved resource
+ * @old: resource pointer
+ */
int release_resource(struct resource *old)
{
int retval;
@@ -315,8 +335,16 @@ static int find_resource(struct resource *root, struct resource *new,
return -EBUSY;
}
-/*
- * Allocate empty slot in the resource tree given range and alignment.
+/**
+ * allocate_resource - allocate empty slot in the resource tree given range & alignment
+ * @root: root resource descriptor
+ * @new: resource descriptor desired by caller
+ * @size: requested resource region size
+ * @min: minimum size to allocate
+ * @max: maximum size to allocate
+ * @align: alignment requested, in bytes
+ * @alignf: alignment function, optional, called if not NULL
+ * @alignf_data: arbitrary data to pass to the @alignf function
*/
int allocate_resource(struct resource *root, struct resource *new,
resource_size_t size, resource_size_t min,
@@ -407,10 +435,15 @@ int insert_resource(struct resource *parent, struct resource *new)
return result;
}
-/*
+/**
+ * adjust_resource - modify a resource's start and size
+ * @res: resource to modify
+ * @start: new start value
+ * @size: new size
+ *
* Given an existing resource, change its start and size to match the
- * arguments. Returns -EBUSY if it can't fit. Existing children of
- * the resource are assumed to be immutable.
+ * arguments. Returns 0 on success, -EBUSY if it can't fit.
+ * Existing children of the resource are assumed to be immutable.
*/
int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size)
{
@@ -456,11 +489,19 @@ EXPORT_SYMBOL(adjust_resource);
* Note how this, unlike the above, knows about
* the IO flag meanings (busy etc).
*
- * Request-region creates a new busy region.
+ * request_region creates a new busy region.
*
- * Check-region returns non-zero if the area is already busy
+ * check_region returns non-zero if the area is already busy.
*
- * Release-region releases a matching busy region.
+ * release_region releases a matching busy region.
+ */
+
+/**
+ * __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
*/
struct resource * __request_region(struct resource *parent,
resource_size_t start, resource_size_t n,
@@ -497,9 +538,23 @@ struct resource * __request_region(struct resource *parent,
}
return res;
}
-
EXPORT_SYMBOL(__request_region);
+/**
+ * __check_region - check if a resource region is busy or free
+ * @parent: parent resource descriptor
+ * @start: resource start address
+ * @n: resource region size
+ *
+ * Returns 0 if the region is free at the moment it is checked,
+ * returns %-EBUSY if the region is busy.
+ *
+ * NOTE:
+ * This function is deprecated because its use is racy.
+ * Even if it returns 0, a subsequent call to request_region()
+ * may fail because another driver etc. just allocated the region.
+ * Do NOT use it. It will be removed from the kernel.
+ */
int __check_region(struct resource *parent, resource_size_t start,
resource_size_t n)
{
@@ -513,9 +568,16 @@ int __check_region(struct resource *parent, resource_size_t start,
kfree(res);
return 0;
}
-
EXPORT_SYMBOL(__check_region);
+/**
+ * __release_region - release a previously reserved resource region
+ * @parent: parent resource descriptor
+ * @start: resource start address
+ * @n: resource region size
+ *
+ * The described resource region must match a currently busy region.
+ */
void __release_region(struct resource *parent, resource_size_t start,
resource_size_t n)
{
@@ -553,7 +615,6 @@ void __release_region(struct resource *parent, resource_size_t start,
"<%016llx-%016llx>\n", (unsigned long long)start,
(unsigned long long)end);
}
-
EXPORT_SYMBOL(__release_region);
/*
OpenPOWER on IntegriCloud