11  *   The Contiguous Memory Allocator (CMA) makes it possible to
32  *   CMA tries to solve this issue by operating on memory regions
38 #define pr_fmt(fmt) "cma: " fmt
52 #include <linux/cma.h>
61 struct cma *dma_contiguous_default_area;
64  * Default global CMA area size can be defined in kernel's .config.
70  * Users, who want to set the size of global CMA area for their system
71  * should use cma= kernel parameter.
98 early_param("cma", early_cma);
102 static struct cma *dma_contiguous_numa_area[MAX_NUMNODES];
104 static struct cma *dma_contiguous_pernuma_area[MAX_NUMNODES];
172 		struct cma **cma;  in dma_numa_cma_reserve()  local
182 			cma = &dma_contiguous_pernuma_area[nid];  in dma_numa_cma_reserve()
185 							 0, false, name, cma, nid);  in dma_numa_cma_reserve()
193 			cma = &dma_contiguous_numa_area[nid];  in dma_numa_cma_reserve()
196 							 name, cma, nid);  in dma_numa_cma_reserve()
268  * @res_cma: Pointer to store the created cma region.
281 				       phys_addr_t limit, struct cma **res_cma,  in dma_contiguous_reserve_area()
335 static struct page *cma_alloc_aligned(struct cma *cma, size_t size, gfp_t gfp)  in cma_alloc_aligned()  argument
339 	return cma_alloc(cma, size >> PAGE_SHIFT, align, gfp & __GFP_NOWARN);  in cma_alloc_aligned()
349  * tries to use per-numa cma, if the allocation fails, it will fallback to
354  * there is no need to waste CMA pages for that kind; it also helps reduce
363 	/* CMA can be used only in the context which permits sleeping */  in dma_alloc_contiguous()
373 		struct cma *cma = dma_contiguous_pernuma_area[nid];  in dma_alloc_contiguous()  local
376 		if (cma) {  in dma_alloc_contiguous()
377 			page = cma_alloc_aligned(cma, size, gfp);  in dma_alloc_contiguous()
382 		cma = dma_contiguous_numa_area[nid];  in dma_alloc_contiguous()
383 		if (cma) {  in dma_alloc_contiguous()
384 			page = cma_alloc_aligned(cma, size, gfp);  in dma_alloc_contiguous()
411 	/* if dev has its own cma, free page from there */  in dma_free_contiguous()
417 		 * otherwise, page is from either per-numa cma or default cma  in dma_free_contiguous()
431 	/* not in any cma, free from buddy */  in dma_free_contiguous()
466 	bool default_cma = of_get_flat_dt_prop(node, "linux,cma-default", NULL);  in rmem_cma_setup()
467 	struct cma *cma;  in rmem_cma_setup()  local
471 		pr_info("Reserved memory: bypass %s node, using cmdline CMA params instead\n",  in rmem_cma_setup()
481 		pr_err("Reserved memory: incorrect alignment of CMA region\n");  in rmem_cma_setup()
485 	err = cma_init_reserved_mem(rmem->base, rmem->size, 0, rmem->name, &cma);  in rmem_cma_setup()
487 		pr_err("Reserved memory: unable to setup CMA region\n");  in rmem_cma_setup()
494 		dma_contiguous_default_area = cma;  in rmem_cma_setup()
497 	rmem->priv = cma;  in rmem_cma_setup()
499 	pr_info("Reserved memory: created CMA memory pool at %pa, size %ld MiB\n",  in rmem_cma_setup()
504 RESERVEDMEM_OF_DECLARE(cma, "shared-dma-pool", rmem_cma_setup);