Commit 39a2d350 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

dma-mapping: add a dma_init_global_coherent helper 



Add a new helper to initialize the global coherent pool.  This both
cleans up the existing initialization which indirects through the
reserved_mem_ops that are normally only used for struct device, and
also allows using the global pool for non-devicetree architectures.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Tested-by: default avatarDillon Min <dillon.minfei@gmail.com>
parent a6933571

include/linux/dma-map-ops.h

+1 −1
Original line number Diff line number Diff line
@@ -177,7 +177,7 @@ void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size, 
int dma_release_from_global_coherent(int order, void *vaddr);

int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *cpu_addr,

		size_t size, int *ret);



int dma_init_global_coherent(phys_addr_t phys_addr, size_t size);

#else

static inline int dma_declare_coherent_memory(struct device *dev,

		phys_addr_t phys_addr, dma_addr_t device_addr, size_t size)

kernel/dma/coherent.c

+14 −18
Original line number Diff line number Diff line
@@ -300,6 +300,18 @@ int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *vaddr, 
					vaddr, size, ret);

}



int dma_init_global_coherent(phys_addr_t phys_addr, size_t size)

{

	struct dma_coherent_mem *mem;



	mem = dma_init_coherent_memory(phys_addr, phys_addr, size, true);

	if (IS_ERR(mem))

		return PTR_ERR(mem);

	dma_coherent_default_memory = mem;

	pr_info("DMA: default coherent area is set\n");

	return 0;

}



/*

 * Support for reserved memory regions defined in device tree

 */
@@ -367,26 +379,10 @@ static int __init rmem_dma_setup(struct reserved_mem *rmem) 


static int __init dma_init_reserved_memory(void)

{

	const struct reserved_mem_ops *ops;

	int ret;



	if (!dma_reserved_default_memory)

		return -ENOMEM;



	ops = dma_reserved_default_memory->ops;



	/*

	 * We rely on rmem_dma_device_init() does not propagate error of

	 * dma_assign_coherent_memory() for "NULL" device.

	 */

	ret = ops->device_init(dma_reserved_default_memory, NULL);



	if (!ret) {

		dma_coherent_default_memory = dma_reserved_default_memory->priv;

		pr_info("DMA: default coherent area is set\n");

	}



	return ret;

	return dma_init_global_coherent(dma_reserved_default_memory->base,

					dma_reserved_default_memory->size);

}



core_initcall(dma_init_reserved_memory);