user/sven/linux.git/kernel/dma/mapping.c, branch v5.15.57

dma-mapping: remove bogus test for pfn_valid from dma_map_resource

2022-04-27T12:38:50Z

commit a9c38c5d267cb94871dfa2de5539c92025c855d7 upstream. dma_map_resource() uses pfn_valid() to ensure the range is not RAM. However, pfn_valid() only checks for availability of the memory map for a PFN but it does not ensure that the PFN is actually backed by RAM. As dma_map_resource() is the only method in DMA mapping APIs that has this check, simply drop the pfn_valid() test from dma_map_resource(). Link: https://lore.kernel.org/all/20210824173741.GC623@arm.com/ Signed-off-by: Mike Rapoport Reviewed-by: Christoph Hellwig Acked-by: David Hildenbrand Link: https://lore.kernel.org/r/20210930013039.11260-2-rppt@kernel.org Signed-off-by: Will Deacon Fixes: 859a85ddf90e ("mm: remove pfn_valid_within() and CONFIG_HOLES_IN_ZONE") Link: https://lore.kernel.org/r/Yl0IZWT2nsiYtqBT@linux.ibm.com Signed-off-by: Georgi Djakov Signed-off-by: Greg Kroah-Hartman

dma-debug: teach add_dma_entry() about DMA_ATTR_SKIP_CPU_SYNC

2021-10-18T10:46:45Z

Mapping something twice should be possible as long as, DMA_ATTR_SKIP_CPU_SYNC is passed to the strictly speaking second relevant mapping operation (that attempts to map the same thing). So, don't issue a warning if the specified condition is met in add_dma_entry(). Signed-off-by: Hamza Mahfooz Signed-off-by: Christoph Hellwig

dma-mapping: fix the kerneldoc for dma_map_sgtable()

2021-10-11T11:43:04Z

htmldocs began producing the following warnings: kernel/dma/mapping.c:256: WARNING: Definition list ends without a blank line; unexpected unindent. kernel/dma/mapping.c:257: WARNING: Bullet list ends without a blank line; unexpected unindent. Reformatting the list without hyphens fixes the warnings and produces both a readable text and HTML output. Fixes: fffe3cc8c219 ("dma-mapping: allow map_sg() ops to return negative error code") Reported-by: Stephen Rothwell Signed-off-by: Logan Gunthorpe Signed-off-by: Christoph Hellwig

dma-mapping: fix the kerneldoc for dma_map_sg_attrs

2021-09-06T12:40:47Z

Add the missing description for the nents parameter, and fix a trivial misalignment. Fixes: fffe3cc8c219 ("dma-mapping: allow map_sg() ops to return negative error codes") Reported-by: Stephen Rothwell Signed-off-by: Christoph Hellwig

dma-mapping: return an unsigned int from dma_map_sg{,_attrs}

2021-08-14T07:18:36Z

These can only return 0 for failure or the number of entries, so turn the return value into an unsigned int. Signed-off-by: Christoph Hellwig Reviewed-by: Logan Gunthorpe

dma-mapping: disallow .map_sg operations from returning zero on error

2021-08-09T15:15:02Z

Now that all the .map_sg operations have been converted to returning proper error codes, drop the code to handle a zero return value, add a warning if a zero is returned. Signed-off-by: Logan Gunthorpe Signed-off-by: Christoph Hellwig

dma-mapping: allow map_sg() ops to return negative error codes

2021-08-09T15:13:02Z

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 Signed-off-by: Christoph Hellwig

dma-mapping: add a dma_alloc_noncontiguous API

2021-03-15T09:02:31Z

Add a new API that returns a potentiall virtually non-contigous sg_table and a DMA address. This API is only properly implemented for dma-iommu and will simply return a contigious chunk as a fallback. The intent is that drivers can use this API if either: - no kernel mapping or only temporary kernel mappings are required. That is as a better replacement for DMA_ATTR_NO_KERNEL_MAPPING - a kernel mapping is required for cached and DMA mapped pages, but the driver also needs the pages to e.g. map them to userspace. In that sense it is a replacement for some aspects of the recently removed and never fully implemented DMA_ATTR_NON_CONSISTENT Signed-off-by: Christoph Hellwig Reviewed-by: Tomasz Figa Tested-by: Ricardo Ribalda

dma-mapping: refactor dma_{alloc,free}_pages

2021-03-15T09:02:31Z

Factour out internal versions without the dma_debug calls in preparation for callers that will need different dma_debug calls. Note that this changes the dma_debug calls to get the not page aligned size values, but as long as alloc and free agree on one variant we are fine. Signed-off-by: Christoph Hellwig Reviewed-by: Tomasz Figa Tested-by: Ricardo Ribalda

dma-mapping: add a dma_mmap_pages helper

2021-03-15T09:02:31Z

Add a helper to map memory allocated using dma_alloc_pages into a user address space, similar to the dma_alloc_attrs function for coherent allocations. Signed-off-by: Christoph Hellwig Reviewed-by: Tomasz Figa Tested-by: Ricardo Ribalda