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linux_dsm_epyc7002/include/linux/dma-mapping.h
Ricardo Ribalda Delgado 04abab6982 include/dma-mapping: Clarify output of dma_map_sg 
Although dma_map_sg returns 0 on error and it cannot return a
value < 0, the function returns a signed integer.

Most of the time, this function is used with a scatterlist structure.
This structure uses an unsigned integer for the number of memory.

A dma developer that has not read in detail DMA-API.txt, can wrongly
return a value < 0 on error.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
2015-03-09 13:05:47 +01:00

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#ifndef _LINUX_DMA_MAPPING_H
#define _LINUX_DMA_MAPPING_H
#include <linux/string.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/dma-attrs.h>
#include <linux/dma-direction.h>
#include <linux/scatterlist.h>
/*
* A dma_addr_t can hold any valid DMA or bus address for the platform.
* It can be given to a device to use as a DMA source or target. A CPU cannot
* reference a dma_addr_t directly because there may be translation between
* its physical address space and the bus address space.
*/
struct dma_map_ops {
void* (*alloc)(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp,
struct dma_attrs *attrs);
void (*free)(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle,
struct dma_attrs *attrs);
int (*mmap)(struct device *, struct vm_area_struct *,
void *, dma_addr_t, size_t, struct dma_attrs *attrs);
int (*get_sgtable)(struct device *dev, struct sg_table *sgt, void *,
dma_addr_t, size_t, struct dma_attrs *attrs);
dma_addr_t (*map_page)(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction dir,
struct dma_attrs *attrs);
void (*unmap_page)(struct device *dev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs);
/*
* map_sg returns 0 on error and a value > 0 on success.
* It should never return a value < 0.
*/
int (*map_sg)(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction dir,
struct dma_attrs *attrs);
void (*unmap_sg)(struct device *dev,
struct scatterlist *sg, int nents,
enum dma_data_direction dir,
struct dma_attrs *attrs);
void (*sync_single_for_cpu)(struct device *dev,
dma_addr_t dma_handle, size_t size,
enum dma_data_direction dir);
void (*sync_single_for_device)(struct device *dev,
dma_addr_t dma_handle, size_t size,
enum dma_data_direction dir);
void (*sync_sg_for_cpu)(struct device *dev,
struct scatterlist *sg, int nents,
enum dma_data_direction dir);
void (*sync_sg_for_device)(struct device *dev,
struct scatterlist *sg, int nents,
enum dma_data_direction dir);
int (*mapping_error)(struct device *dev, dma_addr_t dma_addr);
int (*dma_supported)(struct device *dev, u64 mask);
int (*set_dma_mask)(struct device *dev, u64 mask);
#ifdef ARCH_HAS_DMA_GET_REQUIRED_MASK
u64 (*get_required_mask)(struct device *dev);
#endif
int is_phys;
};
#define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
#define DMA_MASK_NONE 0x0ULL
static inline int valid_dma_direction(int dma_direction)
{
return ((dma_direction == DMA_BIDIRECTIONAL) ||
(dma_direction == DMA_TO_DEVICE) ||
(dma_direction == DMA_FROM_DEVICE));
}
static inline int is_device_dma_capable(struct device *dev)
{
return dev->dma_mask != NULL && *dev->dma_mask != DMA_MASK_NONE;
}
#ifdef CONFIG_HAS_DMA
#include <asm/dma-mapping.h>
#else
#include <asm-generic/dma-mapping-broken.h>
#endif
static inline u64 dma_get_mask(struct device *dev)
{
if (dev && dev->dma_mask && *dev->dma_mask)
return *dev->dma_mask;
return DMA_BIT_MASK(32);
}
#ifdef CONFIG_ARCH_HAS_DMA_SET_COHERENT_MASK
int dma_set_coherent_mask(struct device *dev, u64 mask);
#else
static inline int dma_set_coherent_mask(struct device *dev, u64 mask)
{
if (!dma_supported(dev, mask))
return -EIO;
dev->coherent_dma_mask = mask;
return 0;
}
#endif
/*
* Set both the DMA mask and the coherent DMA mask to the same thing.
* Note that we don't check the return value from dma_set_coherent_mask()
* as the DMA API guarantees that the coherent DMA mask can be set to
* the same or smaller than the streaming DMA mask.
*/
static inline int dma_set_mask_and_coherent(struct device *dev, u64 mask)
{
int rc = dma_set_mask(dev, mask);
if (rc == 0)
dma_set_coherent_mask(dev, mask);
return rc;
}
/*
* Similar to the above, except it deals with the case where the device
* does not have dev->dma_mask appropriately setup.
*/
static inline int dma_coerce_mask_and_coherent(struct device *dev, u64 mask)
{
dev->dma_mask = &dev->coherent_dma_mask;
return dma_set_mask_and_coherent(dev, mask);
}
extern u64 dma_get_required_mask(struct device *dev);
#ifndef arch_setup_dma_ops
static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base,
u64 size, struct iommu_ops *iommu,
bool coherent) { }
#endif
#ifndef arch_teardown_dma_ops
static inline void arch_teardown_dma_ops(struct device *dev) { }
#endif
static inline unsigned int dma_get_max_seg_size(struct device *dev)
{
return dev->dma_parms ? dev->dma_parms->max_segment_size : 65536;
}
static inline unsigned int dma_set_max_seg_size(struct device *dev,
unsigned int size)
{
if (dev->dma_parms) {
dev->dma_parms->max_segment_size = size;
return 0;
} else
return -EIO;
}
static inline unsigned long dma_get_seg_boundary(struct device *dev)
{
return dev->dma_parms ?
dev->dma_parms->segment_boundary_mask : 0xffffffff;
}
static inline int dma_set_seg_boundary(struct device *dev, unsigned long mask)
{
if (dev->dma_parms) {
dev->dma_parms->segment_boundary_mask = mask;
return 0;
} else
return -EIO;
}
#ifndef dma_max_pfn
static inline unsigned long dma_max_pfn(struct device *dev)
{
return *dev->dma_mask >> PAGE_SHIFT;
}
#endif
static inline void *dma_zalloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag)
{
void *ret = dma_alloc_coherent(dev, size, dma_handle,
flag | __GFP_ZERO);
return ret;
}
#ifdef CONFIG_HAS_DMA
static inline int dma_get_cache_alignment(void)
{
#ifdef ARCH_DMA_MINALIGN
return ARCH_DMA_MINALIGN;
#endif
return 1;
}
#endif
/* flags for the coherent memory api */
#define DMA_MEMORY_MAP 0x01
#define DMA_MEMORY_IO 0x02
#define DMA_MEMORY_INCLUDES_CHILDREN 0x04
#define DMA_MEMORY_EXCLUSIVE 0x08
#ifndef ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
static inline int
dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
dma_addr_t device_addr, size_t size, int flags)
{
return 0;
}
static inline void
dma_release_declared_memory(struct device *dev)
{
}
static inline void *
dma_mark_declared_memory_occupied(struct device *dev,
dma_addr_t device_addr, size_t size)
{
return ERR_PTR(-EBUSY);
}
#endif
/*
* Managed DMA API
*/
extern void *dmam_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp);
extern void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle);
extern void *dmam_alloc_noncoherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp);
extern void dmam_free_noncoherent(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle);
#ifdef ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
extern int dmam_declare_coherent_memory(struct device *dev,
phys_addr_t phys_addr,
dma_addr_t device_addr, size_t size,
int flags);
extern void dmam_release_declared_memory(struct device *dev);
#else /* ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY */
static inline int dmam_declare_coherent_memory(struct device *dev,
phys_addr_t phys_addr, dma_addr_t device_addr,
size_t size, gfp_t gfp)
{
return 0;
}
static inline void dmam_release_declared_memory(struct device *dev)
{
}
#endif /* ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY */
#ifndef CONFIG_HAVE_DMA_ATTRS
struct dma_attrs;
#define dma_map_single_attrs(dev, cpu_addr, size, dir, attrs) \
dma_map_single(dev, cpu_addr, size, dir)
#define dma_unmap_single_attrs(dev, dma_addr, size, dir, attrs) \
dma_unmap_single(dev, dma_addr, size, dir)
#define dma_map_sg_attrs(dev, sgl, nents, dir, attrs) \
dma_map_sg(dev, sgl, nents, dir)
#define dma_unmap_sg_attrs(dev, sgl, nents, dir, attrs) \
dma_unmap_sg(dev, sgl, nents, dir)
#else
static inline void *dma_alloc_writecombine(struct device *dev, size_t size,
dma_addr_t *dma_addr, gfp_t gfp)
{
DEFINE_DMA_ATTRS(attrs);
dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
return dma_alloc_attrs(dev, size, dma_addr, gfp, &attrs);
}
static inline void dma_free_writecombine(struct device *dev, size_t size,
void *cpu_addr, dma_addr_t dma_addr)
{
DEFINE_DMA_ATTRS(attrs);
dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
return dma_free_attrs(dev, size, cpu_addr, dma_addr, &attrs);
}
static inline int dma_mmap_writecombine(struct device *dev,
struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr,
size_t size)
{
DEFINE_DMA_ATTRS(attrs);
dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
return dma_mmap_attrs(dev, vma, cpu_addr, dma_addr, size, &attrs);
}
#endif /* CONFIG_HAVE_DMA_ATTRS */
#ifdef CONFIG_NEED_DMA_MAP_STATE
#define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME) dma_addr_t ADDR_NAME
#define DEFINE_DMA_UNMAP_LEN(LEN_NAME) __u32 LEN_NAME
#define dma_unmap_addr(PTR, ADDR_NAME) ((PTR)->ADDR_NAME)
#define dma_unmap_addr_set(PTR, ADDR_NAME, VAL) (((PTR)->ADDR_NAME) = (VAL))
#define dma_unmap_len(PTR, LEN_NAME) ((PTR)->LEN_NAME)
#define dma_unmap_len_set(PTR, LEN_NAME, VAL) (((PTR)->LEN_NAME) = (VAL))
#else
#define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME)
#define DEFINE_DMA_UNMAP_LEN(LEN_NAME)
#define dma_unmap_addr(PTR, ADDR_NAME) (0)
#define dma_unmap_addr_set(PTR, ADDR_NAME, VAL) do { } while (0)
#define dma_unmap_len(PTR, LEN_NAME) (0)
#define dma_unmap_len_set(PTR, LEN_NAME, VAL) do { } while (0)
#endif
#endif
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