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author | Logan Gunthorpe <logang@deltatee.com> | 2021-07-29 23:15:19 +0300 |
---|---|---|
committer | Christoph Hellwig <hch@lst.de> | 2021-08-09 18:13:02 +0300 |
commit | fffe3cc8c2194f60c4af4fac7f27d25e8828f001 (patch) | |
tree | 355e3659644e50766165690c2d549fd154d684ed /include/linux | |
parent | 173735c346c412d9f084825ecb04f24ada0e2986 (diff) | |
download | linux-fffe3cc8c2194f60c4af4fac7f27d25e8828f001.tar.xz |
dma-mapping: allow map_sg() ops to return negative error codes
Allow dma_map_sgtable() to pass errors from the map_sg() ops. This
will be required for returning appropriate error codes when mapping
P2PDMA memory.
Introduce __dma_map_sg_attrs() which will return the raw error code
from the map_sg operation (whether it be negative or zero). Then add a
dma_map_sg_attrs() wrapper to convert any negative errors to zero to
satisfy the existing calling convention.
dma_map_sgtable() defines three error codes that .map_sg implementations
are allowed to return: -EINVAL, -ENOMEM and -EIO. The latter of which
is a generic return for cases that are passing DMA_MAPPING_ERROR
through.
dma_map_sgtable() will convert a zero error return for old map_sg() ops
into a -EIO return and return any negative errors as reported.
This allows map_sg implementations to start returning multiple
negative error codes. Legacy map_sg implementations can continue
to return zero until they are all converted.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'include/linux')
-rw-r--r-- | include/linux/dma-map-ops.h | 5 | ||||
-rw-r--r-- | include/linux/dma-mapping.h | 35 |
2 files changed, 10 insertions, 30 deletions
diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h index 0d53a96a3d64..2f842498c448 100644 --- a/include/linux/dma-map-ops.h +++ b/include/linux/dma-map-ops.h @@ -41,8 +41,9 @@ struct dma_map_ops { size_t size, enum dma_data_direction dir, unsigned long attrs); /* - * map_sg returns 0 on error and a value > 0 on success. - * It should never return a value < 0. + * map_sg should return a negative error code on error. See + * dma_map_sgtable() for a list of appropriate error codes + * and their meanings. */ int (*map_sg)(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir, unsigned long attrs); diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 183e7103a66d..daa1e360f0ee 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -110,6 +110,8 @@ int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir, unsigned long attrs); +int dma_map_sgtable(struct device *dev, struct sg_table *sgt, + enum dma_data_direction dir, unsigned long attrs); dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr, size_t size, enum dma_data_direction dir, unsigned long attrs); void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size, @@ -174,6 +176,11 @@ static inline void dma_unmap_sg_attrs(struct device *dev, unsigned long attrs) { } +static inline int dma_map_sgtable(struct device *dev, struct sg_table *sgt, + enum dma_data_direction dir, unsigned long attrs) +{ + return -EOPNOTSUPP; +} static inline dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr, size_t size, enum dma_data_direction dir, unsigned long attrs) @@ -344,34 +351,6 @@ static inline void dma_sync_single_range_for_device(struct device *dev, } /** - * dma_map_sgtable - Map the given buffer for DMA - * @dev: The device for which to perform the DMA operation - * @sgt: The sg_table object describing the buffer - * @dir: DMA direction - * @attrs: Optional DMA attributes for the map operation - * - * Maps a buffer described by a scatterlist stored in the given sg_table - * object for the @dir DMA operation by the @dev device. After success the - * ownership for the buffer is transferred to the DMA domain. One has to - * call dma_sync_sgtable_for_cpu() or dma_unmap_sgtable() to move the - * ownership of the buffer back to the CPU domain before touching the - * buffer by the CPU. - * - * Returns 0 on success or -EINVAL on error during mapping the buffer. - */ -static inline int dma_map_sgtable(struct device *dev, struct sg_table *sgt, - enum dma_data_direction dir, unsigned long attrs) -{ - int nents; - - nents = dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs); - if (nents <= 0) - return -EINVAL; - sgt->nents = nents; - return 0; -} - -/** * dma_unmap_sgtable - Unmap the given buffer for DMA * @dev: The device for which to perform the DMA operation * @sgt: The sg_table object describing the buffer |