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

dma-mapping: remove CONFIG_DMA_REMAP

2022-03-03T11:00:57Z

CONFIG_DMA_REMAP is used to build a few helpers around the core vmalloc code, and to use them in case there is a highmem page in dma-direct, and to make dma coherent allocations be able to use non-contiguous pages allocations for DMA allocations in the dma-iommu layer. Right now it needs to be explicitly selected by architectures, and is only done so by architectures that require remapping to deal with devices that are not DMA coherent. Make it unconditional for builds with CONFIG_MMU as it is very little extra code, but makes it much more likely that large DMA allocations succeed on x86. This fixes hot plugging a NVMe thunderbolt SSD for me, which tries to allocate a 1MB buffer that is otherwise hard to obtain due to memory fragmentation on a heavily used laptop. Signed-off-by: Christoph Hellwig Reviewed-by: Robin Murphy

Merge branch 'stable/for-linus-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb

2021-09-03T17:34:44Z

Pull swiotlb updates from Konrad Rzeszutek Wilk: "A new feature called restricted DMA pools. It allows SWIOTLB to utilize per-device (or per-platform) allocated memory pools instead of using the global one. The first big user of this is ARM Confidential Computing where the memory for DMA operations can be set per platform" * 'stable/for-linus-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb: (23 commits) swiotlb: use depends on for DMA_RESTRICTED_POOL of: restricted dma: Don't fail device probe on rmem init failure of: Move of_dma_set_restricted_buffer() into device.c powerpc/svm: Don't issue ultracalls if !mem_encrypt_active() s390/pv: fix the forcing of the swiotlb swiotlb: Free tbl memory in swiotlb_exit() swiotlb: Emit diagnostic in swiotlb_exit() swiotlb: Convert io_default_tlb_mem to static allocation of: Return success from of_dma_set_restricted_buffer() when !OF_ADDRESS swiotlb: add overflow checks to swiotlb_bounce swiotlb: fix implicit debugfs declarations of: Add plumbing for restricted DMA pool dt-bindings: of: Add restricted DMA pool swiotlb: Add restricted DMA pool initialization swiotlb: Add restricted DMA alloc/free support swiotlb: Refactor swiotlb_tbl_unmap_single swiotlb: Move alloc_size to swiotlb_find_slots swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing swiotlb: Update is_swiotlb_active to add a struct device argument swiotlb: Update is_swiotlb_buffer to add a struct device argument ...

swiotlb: use depends on for DMA_RESTRICTED_POOL

2021-08-31T18:48:14Z

Use depends on instead of select for DMA_RESTRICTED_POOL; otherwise it will make SWIOTLB user configurable and cause compile errors for some arch (e.g. mips). Fixes: 0b84e4f8b793 ("swiotlb: Add restricted DMA pool initialization") Acked-by: Will Deacon Reported-by: Guenter Roeck Signed-off-by: Claire Chang Signed-off-by: Konrad Rzeszutek Wilk

dma-direct: add support for dma_coherent_default_memory

2021-08-18T14:24:09Z

Add an option to allocate uncached memory for dma_alloc_coherent from the global dma_coherent_default_memory. This will allow to move arm-nommu (and eventually other platforms) to use generic code for allocating uncached memory from a pre-populated pool. Note that this is a different pool from the one that platforms that can remap at runtime use for GFP_ATOMIC allocations for now, although there might be opportunities to eventually end up with a common codebase for the two use cases. Signed-off-by: Christoph Hellwig Tested-by: Dillon Min

swiotlb: Add restricted DMA pool initialization

2021-07-14T00:04:50Z

Add the initialization function to create restricted DMA pools from matching reserved-memory nodes. Regardless of swiotlb setting, the restricted DMA pool is preferred if available. The restricted DMA pools provide a basic level of protection against the DMA overwriting buffer contents at unexpected times. However, to protect against general data leakage and system memory corruption, the system needs to provide a way to lock down the memory access, e.g., MPU. Signed-off-by: Claire Chang Reviewed-by: Christoph Hellwig Tested-by: Stefano Stabellini Tested-by: Will Deacon Signed-off-by: Konrad Rzeszutek Wilk

driver core: lift dma_default_coherent into common code

2021-02-13T08:51:45Z

Lift the dma_default_coherent variable from the mips architecture code to the driver core. This allows an architecture to sdefault all device to be DMA coherent at run time, even if the kernel is build with support for DMA noncoherent device. By allowing device_initialize to set the ->dma_coherent field to this default the amount of arch hooks required for this behavior can be greatly reduced. Signed-off-by: Christoph Hellwig Acked-by: Greg Kroah-Hartman Signed-off-by: Thomas Bogendoerfer

Merge tag 'dma-mapping-5.11' of git://git.infradead.org/users/hch/dma-mapping

2020-12-22T21:19:43Z

Pull dma-mapping updates from Christoph Hellwig: - support for a partial IOMMU bypass (Alexey Kardashevskiy) - add a DMA API benchmark (Barry Song) - misc fixes (Tiezhu Yang, tangjianqiang) * tag 'dma-mapping-5.11' of git://git.infradead.org/users/hch/dma-mapping: selftests/dma: add test application for DMA_MAP_BENCHMARK dma-mapping: add benchmark support for streaming DMA APIs dma-contiguous: fix a typo error in a comment dma-pool: no need to check return value of debugfs_create functions powerpc/dma: Fallback to dma_ops when persistent memory present dma-mapping: Allow mixing bypass and mapped DMA operation

dma-mapping: add benchmark support for streaming DMA APIs

2020-11-27T09:33:42Z

Nowadays, there are increasing requirements to benchmark the performance of dma_map and dma_unmap particually while the device is attached to an IOMMU. This patch enables the support. Users can run specified number of threads to do dma_map_page and dma_unmap_page on a specific NUMA node with the specified duration. Then dma_map_benchmark will calculate the average latency for map and unmap. A difficulity for this benchmark is that dma_map/unmap APIs must run on a particular device. Each device might have different backend of IOMMU or non-IOMMU. So we use the driver_override to bind dma_map_benchmark to a particual device by: For platform devices: echo dma_map_benchmark > /sys/bus/platform/devices/xxx/driver_override echo xxx > /sys/bus/platform/drivers/xxx/unbind echo xxx > /sys/bus/platform/drivers/dma_map_benchmark/bind For PCI devices: echo dma_map_benchmark > /sys/bus/pci/devices/0000:00:01.0/driver_override echo 0000:00:01.0 > /sys/bus/pci/drivers/xxx/unbind echo 0000:00:01.0 > /sys/bus/pci/drivers/dma_map_benchmark/bind Cc: Will Deacon Cc: Shuah Khan Cc: Christoph Hellwig Cc: Marek Szyprowski Cc: Robin Murphy Signed-off-by: Barry Song [hch: folded in two fixes from Colin Ian King ] Signed-off-by: Christoph Hellwig

dma-mapping: Allow mixing bypass and mapped DMA operation

2020-11-27T09:33:40Z

At the moment we allow bypassing DMA ops only when we can do this for the entire RAM. However there are configs with mixed type memory where we could still allow bypassing IOMMU in most cases; POWERPC with persistent memory is one example. This adds an arch hook to determine where bypass can still work and we invoke direct DMA API. The following patch checks the bus limit on POWERPC to allow or disallow direct mapping. This adds a ARCH_HAS_DMA_MAP_DIRECT config option to make the arch_xxxx hooks no-op by default. Signed-off-by: Alexey Kardashevskiy Signed-off-by: Christoph Hellwig

dma-mapping: remove dma_virt_ops

2020-11-17T19:22:07Z

Now that the RDMA core deals with devices that only do DMA mapping in lower layers properly, there is no user for dma_virt_ops and it can be removed. Link: https://lore.kernel.org/r/20201106181941.1878556-11-hch@lst.de Signed-off-by: Christoph Hellwig Signed-off-by: Jason Gunthorpe