Commit 27002253 authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by Bjorn Helgaas
Browse files

resource: Export find_resource_space() 

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

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

Link: https://lore.kernel.org/r/20240507102523.57320-7-ilpo.jarvinen@linux.intel.com


Tested-by: default avatarLidong Wang <lidong.wang@intel.com>
Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
parent 094c0ce5

include/linux/ioport.h

+22 −0
Original line number Diff line number Diff line
@@ -205,6 +205,25 @@ typedef resource_size_t (*resource_alignf)(void *data, 
					   resource_size_t size,

					   resource_size_t align);



/**

 * 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_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 +297,9 @@ static inline bool resource_union(const struct resource *r1, const struct resour 
	return true;

}



int find_resource_space(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)

kernel/resource.c

+4 −22
Original line number Diff line number Diff line
@@ -48,25 +48,6 @@ struct resource iomem_resource = { 
};

EXPORT_SYMBOL(iomem_resource);



/**

 * 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_alignf alignf;

	void *alignf_data;

};



static DEFINE_RWLOCK(resource_lock);



static struct resource *next_resource(struct resource *p, bool skip_children)
@@ -708,12 +689,13 @@ next: if (!this || this->end == root->end) 
 * * %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,

int find_resource_space(struct resource *root, struct resource *new,

			resource_size_t size,

			struct resource_constraint *constraint)

{

	return  __find_resource_space(root, NULL, new, size, constraint);

}

EXPORT_SYMBOL_GPL(find_resource_space);



/**

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