From b50c788a56964a900ebcc817c8a5ad35ddad87b6 Mon Sep 17 00:00:00 2001 From: Rob Herring Date: Tue, 28 Mar 2023 15:15:59 -0500 Subject: 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: Rob Herring --- drivers/of/unittest.c | 7 ++++++- include/linux/of_address.h | 16 ++++++++++++++++ 2 files changed, 22 insertions(+), 1 deletion(-) diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c index 29066ecbed47..eaeb58065acc 100644 --- a/drivers/of/unittest.c +++ b/drivers/of/unittest.c @@ -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 */ diff --git a/include/linux/of_address.h b/include/linux/of_address.h index 1d005439f026..5292f62c1baa 100644 --- a/include/linux/of_address.h +++ b/include/linux/of_address.h @@ -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); -- cgit v1.2.3-59-g8ed1b