Commit b50c788a authored by Rob Herring's avatar Rob Herring
Browse files

of/address: Add of_range_count() helper 

Some users need a count of the number of ranges entries before
iterating over the entries. Typically this is for allocating some data
structure based on the size. Add a helper, of_range_count(), to get the
count. The helper must be called with an struct of_range_parser
initialized by of_range_parser_init().

Link: https://lore.kernel.org/r/20230328-dt-address-helpers-v1-4-e2456c3e77ab@kernel.org


Signed-off-by: default avatarRob Herring <robh@kernel.org>
parent 3d5089c4

drivers/of/unittest.c

+6 −1
Original line number Diff line number Diff line
@@ -1014,7 +1014,7 @@ static void __init of_unittest_bus_ranges(void) 
	struct of_range range;

	struct of_range_parser parser;

	struct resource res;

	int ret, i = 0;

	int ret, count, i = 0;



	np = of_find_node_by_path("/testcase-data/address-tests");

	if (!np) {
@@ -1040,6 +1040,11 @@ static void __init of_unittest_bus_ranges(void) 
		"of_range_to_resource wrong resource start address on node %pOF res=%pR\n",

		np, &res);



	count = of_range_count(&parser);

	unittest(count == 2,

		"of_range_count wrong size on node %pOF count=%d\n",

		np, count);



	/*

	 * Get the "ranges" from the device tree

	 */

include/linux/of_address.h

+16 −0
Original line number Diff line number Diff line
@@ -35,6 +35,22 @@ struct of_pci_range { 
	for (; of_pci_range_parser_one(parser, range);)

#define for_each_of_range for_each_of_pci_range



/*

 * of_range_count - Get the number of "ranges" or "dma-ranges" entries

 * @parser:	Parser state initialized by of_range_parser_init()

 *

 * Returns the number of entries or 0 if none.

 *

 * Note that calling this within or after the for_each_of_range() iterator will

 * be inaccurate giving the number of entries remaining.

 */

static inline int of_range_count(const struct of_range_parser *parser)

{

	if (!parser || !parser->node || !parser->range || parser->range == parser->end)

		return 0;

	return (parser->end - parser->range) / (parser->na + parser->pna + parser->ns);

}



/* Translate a DMA address from device space to CPU space */

extern u64 of_translate_dma_address(struct device_node *dev,

				    const __be32 *in_addr);