From 0fd17e5983337231dc655e9ca0095d2ca3f47405 Mon Sep 17 00:00:00 2001 From: Oreoluwa Babatunde Date: Mon, 26 Jan 2026 18:13:27 +0100 Subject: of: reserved_mem: Allow reserved_mem framework detect "cma=" kernel param When initializing the default cma region, the "cma=" kernel parameter takes priority over a DT defined linux,cma-default region. Hence, give the reserved_mem framework the ability to detect this so that the DT defined cma region can skip initialization accordingly. Signed-off-by: Oreoluwa Babatunde Tested-by: Joy Zou Acked-by: Rob Herring (Arm) Fixes: 8a6e02d0c00e ("of: reserved_mem: Restructure how the reserved memory regions are processed") Fixes: 2c223f7239f3 ("of: reserved_mem: Restructure call site for dma_contiguous_early_fixup()") Link: https://lore.kernel.org/r/20251210002027.1171519-1-oreoluwa.babatunde@oss.qualcomm.com [mszyprow: rebased onto v6.19-rc1, added fixes tags, added a stub for cma_skip_dt_default_reserved_mem() if no CONFIG_DMA_CMA is set] Signed-off-by: Marek Szyprowski --- kernel/dma/contiguous.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c index d8fd6f779f79..0e266979728b 100644 --- a/kernel/dma/contiguous.c +++ b/kernel/dma/contiguous.c @@ -91,6 +91,16 @@ static int __init early_cma(char *p) } early_param("cma", early_cma); +/* + * cma_skip_dt_default_reserved_mem - This is called from the + * reserved_mem framework to detect if the default cma region is being + * set by the "cma=" kernel parameter. + */ +bool __init cma_skip_dt_default_reserved_mem(void) +{ + return size_cmdline != -1; +} + #ifdef CONFIG_DMA_NUMA_CMA static struct cma *dma_contiguous_numa_area[MAX_NUMNODES]; @@ -470,12 +480,6 @@ static int __init rmem_cma_setup(struct reserved_mem *rmem) struct cma *cma; int err; - if (size_cmdline != -1 && default_cma) { - pr_info("Reserved memory: bypass %s node, using cmdline CMA params instead\n", - rmem->name); - return -EBUSY; - } - if (!of_get_flat_dt_prop(node, "reusable", NULL) || of_get_flat_dt_prop(node, "no-map", NULL)) return -EINVAL; -- cgit v1.2.3