linux_dsm_epyc7002/include/linux/swiotlb.h
Geert Uytterhoeven fff5d99225 swiotlb: Add swiotlb=noforce debug option
On architectures like arm64, swiotlb is tied intimately to the core
architecture DMA support. In addition, ZONE_DMA cannot be disabled.

To aid debugging and catch devices not supporting DMA to memory outside
the 32-bit address space, add a kernel command line option
"swiotlb=noforce", which disables the use of bounce buffers.
If specified, trying to map memory that cannot be used with DMA will
fail, and a rate-limited warning will be printed.

Note that io_tlb_nslabs is set to 1, which is the minimal supported
value.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2016-12-19 09:05:20 -05:00

125 lines
3.6 KiB
C

#ifndef __LINUX_SWIOTLB_H
#define __LINUX_SWIOTLB_H
#include <linux/dma-direction.h>
#include <linux/init.h>
#include <linux/types.h>
struct device;
struct page;
struct scatterlist;
enum swiotlb_force {
SWIOTLB_NORMAL, /* Default - depending on HW DMA mask etc. */
SWIOTLB_FORCE, /* swiotlb=force */
SWIOTLB_NO_FORCE, /* swiotlb=noforce */
};
extern enum swiotlb_force swiotlb_force;
/*
* Maximum allowable number of contiguous slabs to map,
* must be a power of 2. What is the appropriate value ?
* The complexity of {map,unmap}_single is linearly dependent on this value.
*/
#define IO_TLB_SEGSIZE 128
/*
* log of the size of each IO TLB slab. The number of slabs is command line
* controllable.
*/
#define IO_TLB_SHIFT 11
extern void swiotlb_init(int verbose);
int swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose);
extern unsigned long swiotlb_nr_tbl(void);
unsigned long swiotlb_size_or_default(void);
extern int swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs);
/*
* Enumeration for sync targets
*/
enum dma_sync_target {
SYNC_FOR_CPU = 0,
SYNC_FOR_DEVICE = 1,
};
/* define the last possible byte of physical address space as a mapping error */
#define SWIOTLB_MAP_ERROR (~(phys_addr_t)0x0)
extern phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
dma_addr_t tbl_dma_addr,
phys_addr_t phys, size_t size,
enum dma_data_direction dir,
unsigned long attrs);
extern void swiotlb_tbl_unmap_single(struct device *hwdev,
phys_addr_t tlb_addr,
size_t size, enum dma_data_direction dir,
unsigned long attrs);
extern void swiotlb_tbl_sync_single(struct device *hwdev,
phys_addr_t tlb_addr,
size_t size, enum dma_data_direction dir,
enum dma_sync_target target);
/* Accessory functions. */
extern void
*swiotlb_alloc_coherent(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t flags);
extern void
swiotlb_free_coherent(struct device *hwdev, size_t size,
void *vaddr, dma_addr_t dma_handle);
extern dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction dir,
unsigned long attrs);
extern void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
size_t size, enum dma_data_direction dir,
unsigned long attrs);
extern int
swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
enum dma_data_direction dir,
unsigned long attrs);
extern void
swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
int nelems, enum dma_data_direction dir,
unsigned long attrs);
extern void
swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
size_t size, enum dma_data_direction dir);
extern void
swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
int nelems, enum dma_data_direction dir);
extern void
swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
size_t size, enum dma_data_direction dir);
extern void
swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
int nelems, enum dma_data_direction dir);
extern int
swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr);
extern int
swiotlb_dma_supported(struct device *hwdev, u64 mask);
#ifdef CONFIG_SWIOTLB
extern void __init swiotlb_free(void);
#else
static inline void swiotlb_free(void) { }
#endif
extern void swiotlb_print_info(void);
extern int is_swiotlb_buffer(phys_addr_t paddr);
#endif /* __LINUX_SWIOTLB_H */