linux/kernel/dma/Kconfig, branch v5.8

dma-mapping: DMA_COHERENT_POOL should select GENERIC_ALLOCATOR

2020-06-23T12:13:58Z

The dma coherent pool code needs genalloc. Move the select over from DMA_REMAP, which doesn't actually need it. Fixes: dbed452a078d ("dma-pool: decouple DMA_REMAP from DMA_COHERENT_POOL") Reported-by: kernel test robot Signed-off-by: Christoph Hellwig Acked-by: David Rientjes

dma-direct: re-enable mmap for !CONFIG_MMU

2020-06-17T07:29:31Z

nommu configfs can trivially map the coherent allocations to user space, as no actual page table setup is required and the kernel and the user space programs share the same address space. Fixes: 62fcee9a3bd7 ("dma-mapping: remove CONFIG_ARCH_NO_COHERENT_DMA_MMAP") Signed-off-by: Christoph Hellwig Reported-by: dillon min Reviewed-by: Vladimir Murzin Tested-by: dillon min

dma-pool: decouple DMA_REMAP from DMA_COHERENT_POOL

2020-06-15T06:35:30Z

DMA_REMAP is an unnecessary requirement for AMD SEV, which requires DMA_COHERENT_POOL, so avoid selecting it when it is otherwise unnecessary. The only other requirement for DMA coherent pools is DMA_DIRECT_REMAP, so ensure that properly selects the config option when needed. Fixes: 82fef0ad811f ("x86/mm: unencrypted non-blocking DMA allocations use coherent pools") Reported-by: Alex Xu (Hello71) Signed-off-by: David Rientjes Tested-by: Alex Xu (Hello71) Signed-off-by: Christoph Hellwig

dma-remap: separate DMA atomic pools from direct remap code

2020-04-20T10:08:45Z

DMA atomic pools will be needed beyond only CONFIG_DMA_DIRECT_REMAP so separate them out into their own file. This also adds a new Kconfig option that can be subsequently used for options, such as CONFIG_AMD_MEM_ENCRYPT, that will utilize the coherent pools but do not have a dependency on direct remapping. For this patch alone, there is no functional change introduced. Reviewed-by: Christoph Hellwig Signed-off-by: David Rientjes [hch: fixup copyrights and remove unused includes] Signed-off-by: Christoph Hellwig

dma-direct: provide mmap and get_sgtable method overrides

2019-11-11T09:52:15Z

For dma-direct we know that the DMA address is an encoding of the physical address that we can trivially decode. Use that fact to provide implementations that do not need the arch_dma_coherent_to_pfn architecture hook. Note that we still can only support mmap of non-coherent memory only if the architecture provides a way to set an uncached bit in the page tables. This must be true for architectures that use the generic remap helpers, but other architectures can also manually select it. Signed-off-by: Christoph Hellwig Reviewed-by: Max Filippov

dma-mapping: remove arch_dma_mmap_pgprot

2019-08-29T14:43:22Z

arch_dma_mmap_pgprot is used for two things: 1) to override the "normal" uncached page attributes for mapping memory coherent to devices that can't snoop the CPU caches 2) to provide the special DMA_ATTR_WRITE_COMBINE semantics on older arm systems and some mips platforms Replace one with the pgprot_dmacoherent macro that is already provided by arm and much simpler to use, and lift the DMA_ATTR_WRITE_COMBINE handling to common code with an explicit arch opt-in. Signed-off-by: Christoph Hellwig Acked-by: Geert Uytterhoeven # m68k Acked-by: Paul Burton # mips

dma-direct: Force unencrypted DMA under SME for certain DMA masks

2019-07-16T20:15:46Z

If a device doesn't support DMA to a physical address that includes the encryption bit (currently bit 47, so 48-bit DMA), then the DMA must occur to unencrypted memory. SWIOTLB is used to satisfy that requirement if an IOMMU is not active (enabled or configured in passthrough mode). However, commit fafadcd16595 ("swiotlb: don't dip into swiotlb pool for coherent allocations") modified the coherent allocation support in SWIOTLB to use the DMA direct coherent allocation support. When an IOMMU is not active, this resulted in dma_alloc_coherent() failing for devices that didn't support DMA addresses that included the encryption bit. Addressing this requires changes to the force_dma_unencrypted() function in kernel/dma/direct.c. Since the function is now non-trivial and SME/SEV specific, update the DMA direct support to add an arch override for the force_dma_unencrypted() function. The arch override is selected when CONFIG_AMD_MEM_ENCRYPT is set. The arch override function resides in the arch/x86/mm/mem_encrypt.c file and forces unencrypted DMA when either SEV is active or SME is active and the device does not support DMA to physical addresses that include the encryption bit. Fixes: fafadcd16595 ("swiotlb: don't dip into swiotlb pool for coherent allocations") Suggested-by: Christoph Hellwig Signed-off-by: Tom Lendacky Acked-by: Thomas Gleixner [hch: moved the force_dma_unencrypted declaration to dma-mapping.h, fold the s390 fix from Halil Pasic] Signed-off-by: Christoph Hellwig

treewide: Add SPDX license identifier - Makefile/Kconfig

2019-05-21T08:50:46Z

Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

dma-mapping: add a Kconfig symbol to indicate arch_dma_prep_coherent presence

2019-05-06T13:04:40Z

Add a Kconfig symbol that indicates an architecture provides a arch_dma_prep_coherent implementation, and provide a stub otherwise. This will allow the generic dma-iommu code to use it while still allowing to be built for cache coherent architectures. Signed-off-by: Christoph Hellwig Reviewed-by: Robin Murphy

dma: select GENERIC_ALLOCATOR for DMA_REMAP

2019-04-08T15:51:22Z

When DMA_REMAP is enabled, code in remap.c needs generic allocator. It currently worked since few architectures uses it (arm64, csky) and they both select GENERIC_ALLOCATOR. Select it when using DMA_REMAP to have correct dependencies. Signed-off-by: Clement Leger Signed-off-by: Christoph Hellwig