include/linux/dma-direct.h

Source file repositories/reference/linux-study-clean/include/linux/dma-direct.h

File Facts

System
Linux kernel
Corpus path
include/linux/dma-direct.h
Extension
.h
Size
4118 bytes
Lines
154
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct bus_dma_region {
	phys_addr_t	cpu_start;
	dma_addr_t	dma_start;
	u64		size;
};

static inline dma_addr_t translate_phys_to_dma(struct device *dev,
		phys_addr_t paddr)
{
	const struct bus_dma_region *m;

	for (m = dev->dma_range_map; m->size; m++) {
		u64 offset = paddr - m->cpu_start;

		if (paddr >= m->cpu_start && offset < m->size)
			return m->dma_start + offset;
	}

	/* make sure dma_capable fails when no translation is available */
	return DMA_MAPPING_ERROR;
}

static inline phys_addr_t translate_dma_to_phys(struct device *dev,
		dma_addr_t dma_addr)
{
	const struct bus_dma_region *m;

	for (m = dev->dma_range_map; m->size; m++) {
		u64 offset = dma_addr - m->dma_start;

		if (dma_addr >= m->dma_start && offset < m->size)
			return m->cpu_start + offset;
	}

	return (phys_addr_t)-1;
}

static inline dma_addr_t dma_range_map_min(const struct bus_dma_region *map)
{
	dma_addr_t ret = (dma_addr_t)U64_MAX;

	for (; map->size; map++)
		ret = min(ret, map->dma_start);
	return ret;
}

static inline dma_addr_t dma_range_map_max(const struct bus_dma_region *map)
{
	dma_addr_t ret = 0;

	for (; map->size; map++)
		ret = max(ret, map->dma_start + map->size - 1);
	return ret;
}

#ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA
#include <asm/dma-direct.h>
#ifndef phys_to_dma_unencrypted
#define phys_to_dma_unencrypted		phys_to_dma
#endif
#else
static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
{
	if (dev->dma_range_map)
		return translate_phys_to_dma(dev, paddr);
	return paddr;
}

static inline dma_addr_t phys_to_dma_unencrypted(struct device *dev,
						phys_addr_t paddr)
{
	return dma_addr_unencrypted(__phys_to_dma(dev, paddr));
}
/*
 * If memory encryption is supported, phys_to_dma will set the memory encryption
 * bit in the DMA address, and dma_to_phys will clear it.
 * phys_to_dma_unencrypted is for use on special unencrypted memory like swiotlb
 * buffers.
 */
static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
{
	return dma_addr_encrypted(__phys_to_dma(dev, paddr));
}

static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
{
	phys_addr_t paddr;

	dma_addr = dma_addr_canonical(dma_addr);
	if (dev->dma_range_map)

Annotation

Implementation Notes