[PATCH 6/7] resource: Export find_empty_resource_slot()

Ilpo Järvinen
2023-12-22T12:30:25Z

PCI bridge window logic needs to find out in advance to the actual
allocation if there is an empty slot big enough to fit the window.

Export find_empty_resource_slot() for the purpose. Also move the struct
resource_constraint into generic header to be able to use the new
interface.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
include/linux/ioport.h | 22 ++++++++++++++++++++++
kernel/resource.c | 25 ++++---------------------
2 files changed, 26 insertions(+), 21 deletions(-)

diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index ce02f45e9c2c..0e911393dfb2 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -205,6 +205,24 @@ typedef resource_size_t (*resource_alignf)(void *data,
resource_size_t size,
resource_size_t align);

+/**
+ * resource_constraint - constraints to be met while searching empty resource slots
+ * @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 slot
+ * @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_empty_resource_slot(). @alignf can be NULL indicating no alignment
+ * beyond @align is necessary.
+ */
+struct resource_constraint {
+ resource_size_t min, max, align;
+ resource_alignf alignf;
+ void *alignf_data;
+};
+
/* PC/ISA/whatever - the normal PC address spaces: IO and memory */
extern struct resource ioport_resource;
extern struct resource iomem_resource;
@@ -278,6 +296,10 @@ static inline bool resource_union(const struct resource *r1, const struct resour
return true;
}

+int find_empty_resource_slot(struct resource *root, struct resource *new,
+ resource_size_t size,
+ struct resource_constraint *constraint);
+
/* Convenience shorthand with allocation */
#define request_region(start,n,name) __request_region(&ioport_resource, (start), (n), (name), 0)
#define request_muxed_region(start,n,name) __request_region(&ioport_resource, (start), (n), (name), IORESOURCE_MUXED)
diff --git a/kernel/resource.c b/kernel/resource.c
index 80d64b6467b3..2dfe04ba24f3 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -46,24 +46,6 @@ struct resource iomem_resource = {
};
EXPORT_SYMBOL(iomem_resource);

-/**
- * resource_constraint - constraints to be met while searching empty resource slots
- * @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 slot
- * @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_empty_resource_slot(). @alignf can be NULL indicating no alignment
- * beyond @align is necessary.
- */
-struct resource_constraint {
- resource_size_t min, max, align;
- resource_alignf alignf;
- void *alignf_data;
-};
-
static DEFINE_RWLOCK(resource_lock);

static struct resource *next_resource(struct resource *p, bool skip_children)
@@ -651,12 +633,13 @@ next: if (!this || this->end == root->end)
* * %0 - if successful, @new members start, end, and flags are altered.
* * %-EBUSY - if no empty slot was found.
*/
-static int find_empty_resource_slot(struct resource *root, struct resource *new,
- resource_size_t size,
- struct resource_constraint *constraint)
+int find_empty_resource_slot(struct resource *root, struct resource *new,
+ resource_size_t size,
+ struct resource_constraint *constraint)
{
return __find_empty_resource_slot(root, NULL, new, size, constraint);
}
+EXPORT_SYMBOL_GPL(find_empty_resource_slot);

/**
* reallocate_resource - allocate a slot in the resource tree given range & alignment.
--
2.30.2