linux-dev/kernel/dma, branch linus/master

swiotlb: fix setting ->force_bounce

2022-06-02T05:17:59Z

The swiotlb_init refactor messed up assigning ->force_bounce by doing it in different places based on what caused the setting of the flag. Fix this by passing the SWIOTLB_* flags to swiotlb_init_io_tlb_mem and just setting it there. Fixes: c6af2aa9ffc9 ("swiotlb: make the swiotlb_init interface more useful") Reported-by: Nathan Chancellor Signed-off-by: Christoph Hellwig Tested-by: Nathan Chancellor

dma-debug: make things less spammy under memory pressure

2022-06-02T05:17:59Z

Limit the error msg to avoid flooding the console. If you have a lot of threads hitting this at once, they could have already gotten passed the dma_debug_disabled() check before they get to the point of allocation failure, resulting in quite a lot of this error message spamming the log. Use pr_err_once() to limit that. Signed-off-by: Rob Clark Signed-off-by: Christoph Hellwig

dma-direct: don't over-decrypt memory

2022-05-23T13:25:40Z

The original x86 sev_alloc() only called set_memory_decrypted() on memory returned by alloc_pages_node(), so the page order calculation fell out of that logic. However, the common dma-direct code has several potential allocators, not all of which are guaranteed to round up the underlying allocation to a power-of-two size, so carrying over that calculation for the encryption/decryption size was a mistake. Fix it by rounding to a *number* of pages, rather than an order. Until recently there was an even worse interaction with DMA_DIRECT_REMAP where we could have ended up decrypting part of the next adjacent vmalloc area, only averted by no architecture actually supporting both configs at once. Don't ask how I found that one out... Fixes: c10f07aa27da ("dma/direct: Handle force decryption for DMA coherent buffers in common code") Signed-off-by: Robin Murphy Signed-off-by: Christoph Hellwig Acked-by: David Rientjes

swiotlb: max mapping size takes min align mask into account

2022-05-17T09:21:52Z

swiotlb_find_slots() skips slots according to io tlb aligned mask calculated from min aligned mask and original physical address offset. This affects max mapping size. The mapping size can't achieve the IO_TLB_SEGSIZE * IO_TLB_SIZE when original offset is non-zero. This will cause system boot up failure in Hyper-V Isolation VM where swiotlb force is enabled. Scsi layer use return value of dma_max_mapping_size() to set max segment size and it finally calls swiotlb_max_mapping_size(). Hyper-V storage driver sets min align mask to 4k - 1. Scsi layer may pass 256k length of request buffer with 0~4k offset and Hyper-V storage driver can't get swiotlb bounce buffer via DMA API. Swiotlb_find_slots() can't find 256k length bounce buffer with offset. Make swiotlb_max_mapping _size() take min align mask into account. Signed-off-by: Tianyu Lan Signed-off-by: Christoph Hellwig

swiotlb: use the right nslabs-derived sizes in swiotlb_init_late

2022-05-13T10:49:27Z

nslabs can shrink when allocations or the remap don't succeed, so make sure to use it for all sizing. For that remove the bytes value that can get stale and replace it with local calculations and a boolean to indicate if the originally requested size could not be allocated. Fixes: 6424e31b1c05 ("swiotlb: remove swiotlb_init_with_tbl and swiotlb_init_late_with_tbl") Signed-off-by: Christoph Hellwig Reviewed-by: Stefano Stabellini

swiotlb: use the right nslabs value in swiotlb_init_remap

2022-05-13T10:49:18Z

default_nslabs should only be used to initialize nslabs, after that we need to use the local variable that can shrink when allocations or the remap don't succeed. Fixes: 6424e31b1c05 ("swiotlb: remove swiotlb_init_with_tbl and swiotlb_init_late_with_tbl") Signed-off-by: Christoph Hellwig Reviewed-by: Stefano Stabellini

swiotlb: don't panic when the swiotlb buffer can't be allocated

2022-05-13T10:48:58Z

For historical reasons the switlb code paniced when the metadata could not be allocated, but just printed a warning when the actual main swiotlb buffer could not be allocated. Restore this somewhat unexpected behavior as changing it caused a boot failure on the Microchip RISC-V PolarFire SoC Icicle kit. Fixes: 6424e31b1c05 ("swiotlb: remove swiotlb_init_with_tbl and swiotlb_init_late_with_tbl") Reported-by: Conor Dooley Signed-off-by: Christoph Hellwig Reviewed-by: Stefano Stabellini Acked-by: Conor Dooley Tested-by: Conor Dooley

dma-debug: change allocation mode from GFP_NOWAIT to GFP_ATIOMIC

2022-05-11T17:48:34Z

We observed the error "cacheline tracking ENOMEM, dma-debug disabled" during a light system load (copying some files). The reason for this error is that the dma_active_cacheline radix tree uses GFP_NOWAIT allocation - so it can't access the emergency memory reserves and it fails as soon as anybody reaches the watermark. This patch changes GFP_NOWAIT to GFP_ATOMIC, so that it can access the emergency memory reserves. Signed-off-by: Mikulas Patocka Signed-off-by: Christoph Hellwig

dma-direct: don't fail on highmem CMA pages in dma_direct_alloc_pages

2022-05-11T17:48:34Z

When dma_direct_alloc_pages encounters a highmem page it just gives up currently. But what we really should do is to try memory using the page allocator instead - without this platforms with a global highmem CMA pool will fail all dma_alloc_pages allocations. Fixes: efa70f2fdc84 ("dma-mapping: add a new dma_alloc_pages API") Reported-by: Mark O'Neill Signed-off-by: Christoph Hellwig

swiotlb: remove swiotlb_init_with_tbl and swiotlb_init_late_with_tbl

2022-04-18T05:21:14Z

No users left. Signed-off-by: Christoph Hellwig Reviewed-by: Konrad Rzeszutek Wilk Tested-by: Boris Ostrovsky