diff options
Diffstat (limited to 'kernel/resource.c')
| -rw-r--r-- | kernel/resource.c | 83 |
1 files changed, 72 insertions, 11 deletions
diff --git a/kernel/resource.c b/kernel/resource.c index 9db38a1a7520..6de60c12143e 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); /* |