linux_kernel/arch/mips/loongson64/common/dma-swiotlb.c

// SPDX-License-Identifier: GPL-2.0
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/dma-mapping.h>
#include <linux/scatterlist.h>
#include <linux/swiotlb.h>
#include <linux/bootmem.h>

#include <asm/bootinfo.h>
#include <boot_param.h>
#include <dma-coherence.h>

static void *loongson_dma_alloc_coherent(struct device *dev, size_t size,
		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
{
	void *ret = swiotlb_alloc(dev, size, dma_handle, gfp, attrs);

	mb();
	return ret;
}

static dma_addr_t loongson_dma_map_page(struct device *dev, struct page *page,
				unsigned long offset, size_t size,
				enum dma_data_direction dir,
				unsigned long attrs)
{
	dma_addr_t daddr = swiotlb_map_page(dev, page, offset, size,
					dir, attrs);
	mb();
	return daddr;
}

static int loongson_dma_map_sg(struct device *dev, struct scatterlist *sg,
				int nents, enum dma_data_direction dir,
				unsigned long attrs)
{
	int r = swiotlb_map_sg_attrs(dev, sg, nents, dir, attrs);
	mb();

	return r;
}

static void loongson_dma_sync_single_for_device(struct device *dev,
				dma_addr_t dma_handle, size_t size,
				enum dma_data_direction dir)
{
	swiotlb_sync_single_for_device(dev, dma_handle, size, dir);
	mb();
}

static void loongson_dma_sync_sg_for_device(struct device *dev,
				struct scatterlist *sg, int nents,
				enum dma_data_direction dir)
{
	swiotlb_sync_sg_for_device(dev, sg, nents, dir);
	mb();
}

dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
{
	long nid;
#ifdef CONFIG_PHYS48_TO_HT40
	/* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from
	 * Loongson-3's 48bit address space and embed it into 40bit */
	nid = (paddr >> 44) & 0x3;
	paddr = ((nid << 44) ^ paddr) | (nid << 37);
#endif
	return paddr;
}

phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t daddr)
{
	long nid;
#ifdef CONFIG_PHYS48_TO_HT40
	/* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from
	 * Loongson-3's 48bit address space and embed it into 40bit */
	nid = (daddr >> 37) & 0x3;
	daddr = ((nid << 37) ^ daddr) | (nid << 44);
#endif
	return daddr;
}

static const struct dma_map_ops loongson_dma_map_ops = {
	.alloc = loongson_dma_alloc_coherent,
	.free = swiotlb_free,
	.map_page = loongson_dma_map_page,
	.unmap_page = swiotlb_unmap_page,
	.map_sg = loongson_dma_map_sg,
	.unmap_sg = swiotlb_unmap_sg_attrs,
	.sync_single_for_cpu = swiotlb_sync_single_for_cpu,
	.sync_single_for_device = loongson_dma_sync_single_for_device,
	.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
	.sync_sg_for_device = loongson_dma_sync_sg_for_device,
	.mapping_error = swiotlb_dma_mapping_error,
	.dma_supported = swiotlb_dma_supported,
};

void __init plat_swiotlb_setup(void)
{
	swiotlb_init(1);
	mips_dma_map_ops = &loongson_dma_map_ops;
}