[PATCH v3 3/8] resource: Document find_resource_space() and resource_constraint

From: Ilpo Järvinen
Date: Tue May 07 2024 - 06:26:50 EST


Document find_resource_space() and the struct resource_constraint as
they are going to be exposed outside of resource.c.

Tested-by: Lidong Wang <lidong.wang@xxxxxxxxx>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
---
kernel/resource.c | 29 ++++++++++++++++++++++++++---
1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/kernel/resource.c b/kernel/resource.c
index e163e0a8f2f8..3f15a32d9c42 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -48,7 +48,19 @@ struct resource iomem_resource = {
};
EXPORT_SYMBOL(iomem_resource);

-/* constraints to be met while allocating resources */
+/**
+ * struct resource_constraint - constraints to be met while searching empty
+ * resource space
+ * @min: The minimum address for the memory range
+ * @max: The maximum address for the memory range
+ * @align: Alignment for the start address of the empty space
+ * @alignf: Additional alignment constraints callback
+ * @alignf_data: Data provided for @alignf callback
+ *
+ * Contains the range and alignment constraints that have to be met during
+ * find_resource_space(). @alignf can be NULL indicating no alignment beyond
+ * @align is necessary.
+ */
struct resource_constraint {
resource_size_t min, max, align;
resource_size_t (*alignf)(void *, const struct resource *,
@@ -686,8 +698,19 @@ next: if (!this || this->end == root->end)
return -EBUSY;
}

-/*
- * Find empty space in the resource tree given range and alignment.
+/**
+ * find_resource_space - Find empty space in the resource tree
+ * @root: Root resource descriptor
+ * @new: Resource descriptor awaiting an empty resource space
+ * @size: The minimum size of the empty space
+ * @constraint: The range and alignment constraints to be met
+ *
+ * Finds an empty space under @root in the resource tree satisfying range and
+ * alignment @constraints.
+ *
+ * Return:
+ * * %0 - if successful, @new members start, end, and flags are altered.
+ * * %-EBUSY - if no empty space was found.
*/
static int find_resource_space(struct resource *root, struct resource *new,
resource_size_t size,
--
2.39.2