linux-next.git/kernel/dma, branch master

Merge branch 'dma-mapping-for-next' of https://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux.git

2026-10-06T09:38:05+00:00

Merge tag 'dma-mapping-7.3-2026-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux

2026-09-17T15:03:37+00:00

Pull dma-mapping fixes from Marek Szyprowski: "A few fixes for the DMA-mapping code: - resolved regression in accessing encrypted memory by IOMMU-backed devices (Aneesh Kumar K.V) - improved failure handling and removed rare bug in swiotlb/highmem (Donggeun Yoo)" * tag 'dma-mapping-7.3-2026-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux: x86/mm: Don't force unencrypted DMA for IOMMU-backed devices dma-mapping: don't trace the DMA address when the allocation fails swiotlb: use the adjusted address for the highmem page lookup dma-coherent: report a failed reserved memory assignment

swiotlb: use the adjusted address for the highmem page lookup

2026-09-09T06:30:35+00:00

swiotlb_bounce() reads the page frame number from the slot's recorded orig_addr, then advances orig_addr by tlb_offset to reach the address the caller asked about. The highmem branch mixes the two: the offset within the page comes from the adjusted address, the page from the value before it. Once the adjustment crosses a page boundary the pair no longer describes one location, and the whole copy lands one page below the intended one for a positive tlb_offset, one above for a negative one. DMA_FROM_DEVICE writes the device data over the wrong page and leaves the intended one stale, DMA_TO_DEVICE feeds the device from a page the mapping may not cover. Partial syncs through dma_sync_single_range_for_*() are what make tlb_offset non-zero. The branch test is picked the same way, so a slot recorded in lowmem can be adjusted into highmem and the lowmem path then hands a highmem address to phys_to_virt(). Take both from orig_addr once it is final and keep pfn in the branch that uses it. PhysHighMem() asks the question straight from the address, as dma-debug already does. Fixes: 5f89468e2f06 ("swiotlb: manipulate orig_addr when tlb_addr has offset") Cc: stable@vger.kernel.org Signed-off-by: Donggeun Yoo Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20260905084210.148255-1-donggeunyoo.kernel@gmail.com Signed-off-by: Marek Szyprowski

dma-coherent: report a failed reserved memory assignment

2026-09-09T06:30:35+00:00

rmem_dma_device_init() drops the return value of dma_assign_coherent_memory() and always reports success. That call fails with -EBUSY when the device already has a coherent pool, and the file allows only "*one* such region of memory" per device. of_reserved_mem_device_init_by_idx() reads the zero as success. It logs "assigned reserved memory node" for a region that was not assigned and records the pairing, so of_reserved_mem_device_release() later runs rmem_dma_device_release() for it. That clears dev->dma_mem without looking at which region it was called for, dropping the pool the device did get and leaving it on ordinary memory. dma_declare_coherent_memory() checks the same call and releases the memory on failure, and rmem_swiotlb_device_init() propagates its own errors. Return the error here as well, so a device tree that assigns two pools to one device fails the probe instead of half working. Fixes: 7bfa5ab6fa1b ("drivers: dma-coherent: add initialization from device tree") Signed-off-by: Donggeun Yoo Link: https://lore.kernel.org/r/20260905074727.108029-1-donggeunyoo.kernel@gmail.com Signed-off-by: Marek Szyprowski

dma-mapping: use exact allocation for DMA pages

2026-09-07T16:55:12+00:00

DMA page allocation fallbacks use alloc_pages_node() with get_order(size), wasting the unused tail for non-power-of-two requests. Use alloc_pages_exact_nid() and free_pages_exact() so that a buddy fallback retains only requested pages. Signed-off-by: Qingfang Deng Link: https://lore.kernel.org/r/20260903012914.312305-1-qingfang.deng@linux.dev Signed-off-by: Marek Szyprowski

dma-mapping: rename dma_opt_mapping_size()

2026-09-07T16:55:12+00:00

Function dma_opt_mapping_size() implies from its name that it returns a target or sweet spot DMA mapping size. However, it is just an upper limit optimal DMA mapping size. Above this size, DMA mapping performance may significantly degrade. Rename to dma_max_opt_mapping_size() to reflect the real behaviour. Also rename the internal DMA mapping symbols to align with this. The DMA API documentation already described this behaviour properly (so there is nothing to update). Signed-off-by: John Garry Link: https://lore.kernel.org/r/20260831093620.3481337-1-john.g.garry@oracle.com Signed-off-by: Marek Szyprowski

treewide: refresh kmalloc_obj() conversions

2026-09-05T04:37:00+00:00

This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook

Merge tag 'dma-mapping-7.3-2026-08-27' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux

2026-08-27T19:14:19+00:00

Pull dma-mapping fix from Marek Szyprowski: - integer overflow fix for kernel cmdline parser for DMA contiguous initialization code (Alexander Graf) * tag 'dma-mapping-7.3-2026-08-27' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux: dma-contiguous: fix truncation of numa_cma / cma_pernuma sizes >= 2G

Merge tags 'dma-mapping-7.3-2026-08-24' and 'dma-mapping-7.3-2026-08-24-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux

2026-08-24T18:35:46+00:00

Pull dma-mapping updates from Marek Szyprowski: - swiotlb: - new configuration option for the default pool size (Jagadeesh Pagadala) - reduce overhead for high watermark tracking (chenhuguanshen) - minor code cleanups and improvements (Vova Sharaienko, Honglei Huang and Marek Szyprowski) - add proper tracking of the shared DMA state through direct, pool and swiotlb paths (Aneesh Kumar K.V) This is important for confidential-computing * tag 'dma-mapping-7.3-2026-08-24' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux: dma/swiotlb: decouple high watermark tracking from CONFIG_DEBUG_FS MAINTAINERS: update tree for DMA MAPPING HELPERS dma/swiotlb: introduce Kconfig option for compile-time default pool size dma-direct: Improve readability of the dma_direct_map_sg() for P2PDMA case iommu/dma: simplify dma_iova_destroy() and drop the free_iova helper dma-coherent: use KiB in DMA allocation logs dma-coherent: fix spacing coding style issue * tag 'dma-mapping-7.3-2026-08-24-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux: (23 commits) swiotlb: remove unused SWIOTLB_FORCE flag dma: swiotlb: handle set_memory_decrypted() failures dma: swiotlb: free dynamic pools from process context dma-direct: rename ret to cpu_addr in alloc helpers dma-direct: select DMA address encoding from __DMA_ATTR_ALLOC_CC_SHARED dma-direct: set decrypted flag for remapped DMA allocations dma-direct: make dma_direct_map_phys() honor DMA_ATTR_CC_SHARED dma-direct: Move dma_direct_map_phys() to dma/direct.c dma-direct: pass attrs to dma_capable() for DMA_ATTR_CC_SHARED checks dma-mapping: make dma_pgprot() honor __DMA_ATTR_ALLOC_CC_SHARED dma: swiotlb: track pool encryption state and honor DMA_ATTR_CC_SHARED dma: swiotlb: pass mapping attributes by reference dma-pool: track decrypted atomic pools and select them via attrs dma-direct: use __DMA_ATTR_ALLOC_CC_SHARED in alloc/free paths dma-mapping: Add internal shared allocation attribute coco: arm64: s390: powerpc: Mark secure guests with CC_ATTR_GUEST_MEM_ENCRYPT dma-direct: swiotlb: handle swiotlb alloc/free outside __dma_direct_alloc_pages s390: Expose protected virtualization through cc_platform_has() swiotlb: Preserve allocation virtual address for dynamic pools dma: free atomic pool pages by physical address ...

dma-contiguous: fix truncation of numa_cma / cma_pernuma sizes >= 2G

2026-08-24T13:40:07+00:00

numa_cma=0:4G reserves nothing at all. dma_numa_cma_reserve() copies the requested size into a local int before handing it to cma_declare_contiguous_nid(), so 0x100000000 truncates to zero and the loop skips the node silently. Both parameters are documented in kernel-parameters.txt as nn[MG], so that is the syntax the documentation invites. Which bits survive decides what a request turns into: 4G, 8G and 16G reserve nothing, 2G, 3G and 6G sign-extend into a size the allocator rejects with a warning, and 5G quietly reserves 1G. It reaches further than those parameters. On a CMA_SIZE_PERNUMA kernel with no per-node parameter, dma_numa_cma_reserve() takes the per-node size from the default area, so a plain cma=4G on a multi-node machine feeds that size through the same local and loses every per-node area. numa_cma_size[] and pernuma_size_bytes are both phys_addr_t, so use it for the local too, and give early_numa_cma() separate variables for the node id and the size while in there. Fixes: d5cae2261b86 ("dma-contiguous: simplify numa cma area handling") Cc: stable@vger.kernel.org Assisted-by: Kiro:claude-opus-5 Signed-off-by: Alexander Graf Reviewed-by: Feng Tang Link: https://lore.kernel.org/r/20260821224252.70640-1-graf@amazon.com Signed-off-by: Marek Szyprowski