From c39166cd36a1ff9a90aa53b843ef62c24548bc3f Mon Sep 17 00:00:00 2001 From: Andrea della Porta Date: Fri, 14 Mar 2025 12:03:09 +0900 Subject: [PATCH] of: address: Preserve the flags portion on 1:1 dma-ranges mapping BugLink: https://bugs.launchpad.net/bugs/2102266 commit 7f05e20b989ac33c9c0f8c2028ec0a566493548f upstream. A missing or empty dma-ranges in a DT node implies a 1:1 mapping for dma translations. In this specific case, the current behaviour is to zero out the entire specifier so that the translation could be carried on as an offset from zero. This includes address specifier that has flags (e.g. PCI ranges). Once the flags portion has been zeroed, the translation chain is broken since the mapping functions will check the upcoming address specifier against mismatching flags, always failing the 1:1 mapping and its entire purpose of always succeeding. Set to zero only the address portion while passing the flags through. Fixes: dbbdee94734b ("of/address: Merge all of the bus translation code") Cc: stable@vger.kernel.org Signed-off-by: Andrea della Porta Tested-by: Herve Codina Link: https://lore.kernel.org/r/e51ae57874e58a9b349c35e2e877425ebc075d7a.1732441813.git.andrea.porta@suse.com Signed-off-by: Rob Herring (Arm) Signed-off-by: Greg Kroah-Hartman Signed-off-by: Koichiro Den Signed-off-by: Mehmet Basaran --- drivers/of/address.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/of/address.c b/drivers/of/address.c index 397750f9f28a..dc9ff900cd3f 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -444,7 +444,8 @@ static int of_translate_one(struct device_node *parent, struct of_bus *bus, } if (ranges == NULL || rlen == 0) { offset = of_read_number(addr, na); - memset(addr, 0, pna * 4); + /* set address to zero, pass flags through */ + memset(addr + pbus->flag_cells, 0, (pna - pbus->flag_cells) * 4); pr_debug("empty ranges; 1:1 translation\n"); goto finish; }