| Message ID | 20190129084342.26030-4-joro@8bytes.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/5] swiotlb: Introduce swiotlb_max_mapping_size() | expand |
On Tue, Jan 29, 2019 at 09:43:40AM +0100, Joerg Roedel wrote: > From: Joerg Roedel <jroedel@suse.de> > > The function returns the maximum size that can be mapped > using DMA-API functions. The patch also adds the > implementation for direct DMA and a new dma_map_ops pointer > so that other implementations can expose their limit. > > Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > Signed-off-by: Joerg Roedel <jroedel@suse.de> Looks good: Reviewed-by: Christoph Hellwig <hch@lst.de>
On 1/29/19 2:43 AM, Joerg Roedel wrote: > From: Joerg Roedel <jroedel@suse.de> > > The function returns the maximum size that can be mapped > using DMA-API functions. The patch also adds the > implementation for direct DMA and a new dma_map_ops pointer > so that other implementations can expose their limit. > > Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > Signed-off-by: Joerg Roedel <jroedel@suse.de> > --- > Documentation/DMA-API.txt | 8 ++++++++ > include/linux/dma-mapping.h | 16 ++++++++++++++++ > kernel/dma/direct.c | 11 +++++++++++ > 3 files changed, 35 insertions(+) > > diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt > index e133ccd60228..acfe3d0f78d1 100644 > --- a/Documentation/DMA-API.txt > +++ b/Documentation/DMA-API.txt > @@ -195,6 +195,14 @@ Requesting the required mask does not alter the current mask. If you > wish to take advantage of it, you should issue a dma_set_mask() > call to set the mask to the value returned. > > +:: > + > + size_t > + dma_direct_max_mapping_size(struct device *dev); > + > +Returns the maximum size of a mapping for the device. The size parameter > +of the mapping functions like dma_map_single(), dma_map_page() and > +others should not be larger than the returned value. > > Part Id - Streaming DMA mappings > -------------------------------- > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h > index f6ded992c183..a3ca8a71a704 100644 > --- a/include/linux/dma-mapping.h > +++ b/include/linux/dma-mapping.h > @@ -130,6 +130,7 @@ struct dma_map_ops { > enum dma_data_direction direction); > int (*dma_supported)(struct device *dev, u64 mask); > u64 (*get_required_mask)(struct device *dev); > + size_t (*max_mapping_size)(struct device *dev); > }; > > #define DMA_MAPPING_ERROR (~(dma_addr_t)0) > @@ -257,6 +258,8 @@ static inline void dma_direct_sync_sg_for_cpu(struct device *dev, > } > #endif > > +size_t dma_direct_max_mapping_size(struct device *dev); > + > #ifdef CONFIG_HAS_DMA > #include <asm/dma-mapping.h> > > @@ -440,6 +443,19 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr) > return 0; > } > > +static inline size_t dma_max_mapping_size(struct device *dev) > +{ > + const struct dma_map_ops *ops = get_dma_ops(dev); > + size_t size = SIZE_MAX; > + > + if (dma_is_direct(ops)) > + size = dma_direct_max_mapping_size(dev); > + else if (ops && ops->max_mapping_size) > + size = ops->max_mapping_size(dev); > + > + return size; > +} > + > void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, > gfp_t flag, unsigned long attrs); > void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, > diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c > index 355d16acee6d..6310ad01f915 100644 > --- a/kernel/dma/direct.c > +++ b/kernel/dma/direct.c > @@ -380,3 +380,14 @@ int dma_direct_supported(struct device *dev, u64 mask) > */ > return mask >= __phys_to_dma(dev, min_mask); > } > + > +size_t dma_direct_max_mapping_size(struct device *dev) > +{ > + size_t size = SIZE_MAX; > + > + /* If SWIOTLB is active, use its maximum mapping size */ > + if (is_swiotlb_active()) > + size = swiotlb_max_mapping_size(dev); > + > + return size; > +} When I build with these patches and with the virtio devices as modules I get a build failure. Looks like this needs an EXPORT_SYMBOL() (I'm assuming EXPORT_SYMBOL for DMA functions and not EXPORT_SYMBOL_GPL?). Thanks, Tom >
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index e133ccd60228..acfe3d0f78d1 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -195,6 +195,14 @@ Requesting the required mask does not alter the current mask. If you wish to take advantage of it, you should issue a dma_set_mask() call to set the mask to the value returned. +:: + + size_t + dma_direct_max_mapping_size(struct device *dev); + +Returns the maximum size of a mapping for the device. The size parameter +of the mapping functions like dma_map_single(), dma_map_page() and +others should not be larger than the returned value. Part Id - Streaming DMA mappings -------------------------------- diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index f6ded992c183..a3ca8a71a704 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -130,6 +130,7 @@ struct dma_map_ops { enum dma_data_direction direction); int (*dma_supported)(struct device *dev, u64 mask); u64 (*get_required_mask)(struct device *dev); + size_t (*max_mapping_size)(struct device *dev); }; #define DMA_MAPPING_ERROR (~(dma_addr_t)0) @@ -257,6 +258,8 @@ static inline void dma_direct_sync_sg_for_cpu(struct device *dev, } #endif +size_t dma_direct_max_mapping_size(struct device *dev); + #ifdef CONFIG_HAS_DMA #include <asm/dma-mapping.h> @@ -440,6 +443,19 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr) return 0; } +static inline size_t dma_max_mapping_size(struct device *dev) +{ + const struct dma_map_ops *ops = get_dma_ops(dev); + size_t size = SIZE_MAX; + + if (dma_is_direct(ops)) + size = dma_direct_max_mapping_size(dev); + else if (ops && ops->max_mapping_size) + size = ops->max_mapping_size(dev); + + return size; +} + void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs); void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 355d16acee6d..6310ad01f915 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -380,3 +380,14 @@ int dma_direct_supported(struct device *dev, u64 mask) */ return mask >= __phys_to_dma(dev, min_mask); } + +size_t dma_direct_max_mapping_size(struct device *dev) +{ + size_t size = SIZE_MAX; + + /* If SWIOTLB is active, use its maximum mapping size */ + if (is_swiotlb_active()) + size = swiotlb_max_mapping_size(dev); + + return size; +}