Commit 8c8c5a49 authored by Nicolas Saenz Julienne's avatar Nicolas Saenz Julienne Committed by Christoph Hellwig
Browse files

dma-contiguous: CMA: give precedence to cmdline 



Although the device tree might contain a reserved-memory DT node
dedicated as the default CMA pool, users might want to change CMA's
parameters using the kernel command line for debugging purposes and
whatnot. Honor this by bypassing the reserved memory CMA setup, which
will ultimately end up freeing the memblock and allow the command line
CMA configuration routine to run.

Signed-off-by: default avatarNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: default avatarPhil Elwell <phil@raspberrypi.org>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent d5226fa6

kernel/dma/contiguous.c

+8 −1
Original line number Diff line number Diff line
@@ -302,9 +302,16 @@ static int __init rmem_cma_setup(struct reserved_mem *rmem) 
	phys_addr_t align = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);

	phys_addr_t mask = align - 1;

	unsigned long node = rmem->fdt_node;

	bool default_cma = of_get_flat_dt_prop(node, "linux,cma-default", NULL);

	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;
@@ -322,7 +329,7 @@ static int __init rmem_cma_setup(struct reserved_mem *rmem) 
	/* Architecture specific contiguous memory fixup. */

	dma_contiguous_early_fixup(rmem->base, rmem->size);



	if (of_get_flat_dt_prop(node, "linux,cma-default", NULL))

	if (default_cma)

		dma_contiguous_set_default(cma);



	rmem->ops = &rmem_cma_ops;