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2026-09-09dma-coherent: report a failed reserved memory assignmentDonggeun Yoo
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 <donggeunyoo.kernel@gmail.com> Link: https://lore.kernel.org/r/20260905074727.108029-1-donggeunyoo.kernel@gmail.com Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
2026-08-24Merge tags 'dma-mapping-7.3-2026-08-24' and 'dma-mapping-7.3-2026-08-24-2' ↵Linus Torvalds
of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux 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 ...
2026-08-04mm: prefer vma_[start,end]_pgoff() to vma->vm_pgoff in kernel/Lorenzo Stoakes
Be consistent in using vma_start_pgoff() and vma_end_pgoff(), which clearly indicates which part of the VMA the page offset refers to and aids greppability. This is part of a broader series laying the ground to provide a virtual page offset for MAP_PRIVATE-file backed anon folios. No functional change intended. Link: https://lore.kernel.org/20260710-b4-pre-scalable-cow-v2-19-2a5aa403d977@kernel.org Signed-off-by: Lorenzo Stoakes <ljs@kernel.org> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> # for kernel/dma Reviewed-by: Gregory Price <gourry@gourry.net> Acked-by: Pedro Falcato <pfalcato@suse.de> Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Ackerley Tng <ackerleytng@google.com> Cc: David Hildenbrand (Arm) <david@kernel.org> Cc: Kai Huang <kai.huang@intel.com> Cc: SJ Park <sj@kernel.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Liam R. Howlett (Oracle) <liam@infradead.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-07-13dma-coherent: use KiB in DMA allocation logsVova Sharaienko
Update DMA reserved memory pool allocation log messages to display sizes in KiB instead of MiB. Using MiB caused allocations less than 1 MiB to be logged as 0 MiB due to integer truncation. KiB provides better precision for smaller memory regions specified in the Device Tree. Signed-off-by: Vova Sharaienko <sharaienko@google.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://lore.kernel.org/r/20260629223759.2637162-1-sharaienko@google.com
2026-07-13dma-coherent: fix spacing coding style issueVova Sharaienko
Fixed spacing around * coding style issue Signed-off-by: Vova Sharaienko <sharaienko@google.com> [mszyprow: changed patch prefix] Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://lore.kernel.org/r/20260623000821.2269955-1-sharaienko@google.com
2026-03-26of: reserved_mem: switch to ops based OF_DECLARE()Marek Szyprowski
Move init function from OF_DECLARE() argument to the given reserved memory region ops structure and then pass that structure to the OF_DECLARE() initializer. This node_init callback is mandatory for the reserved mem driver. Such change makes it possible in the future to add more functions called by the generic code before given memory region is initialized and rmem object is created. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://patch.msgid.link/20260325090023.3175348-4-m.szyprowski@samsung.com Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
2026-03-26of: reserved_mem: use -ENODEV instead of -ENOENTMarek Szyprowski
When given reserved memory region doesn't really support given node, return -ENODEV instead of -ENOENT. Then fix __reserved_mem_init_node() function to properly propagate error code different from -ENODEV instead of silently ignoring it. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://patch.msgid.link/20260325090023.3175348-3-m.szyprowski@samsung.com Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
2026-03-26of: reserved_mem: remove fdt node from the structureMarek Szyprowski
FDT node is not needed for anything besides the initialization, so it can be simply passed as an argument to the reserved memory region init function. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://patch.msgid.link/20260325090023.3175348-2-m.szyprowski@samsung.com Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds
This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2025-04-22dma-coherent: Warn if OF reserved memory is beyond current coherent DMA maskChen-Yu Tsai
When a reserved memory region described in the device tree is attached to a device, it is expected that the device's limitations are correctly included in that description. However, if the device driver failed to implement DMA address masking or addressing beyond the default 32 bits (on arm64), then bad things could happen because the DMA address was truncated, such as playing back audio with no actual audio coming out, or DMA overwriting random blocks of kernel memory. Check against the coherent DMA mask when the memory regions are attached to the device. Give a warning when the memory region can not be covered by the mask. A warning instead of a hard error was chosen, because it is possible that existing drivers could be working fine even if they forgot to extend the coherent DMA mask. Signed-off-by: Chen-Yu Tsai <wenst@chromium.org> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://lore.kernel.org/r/20250421083930.374173-1-wenst@chromium.org
2024-11-14dma-mapping: save base/size instead of pointer to shared DMA poolGeert Uytterhoeven
On RZ/Five, which is non-coherent, and uses CONFIG_DMA_GLOBAL_POOL=y: Oops - store (or AMO) access fault [#1] CPU: 0 UID: 0 PID: 1 Comm: swapper Not tainted 6.12.0-rc1-00015-g8a6e02d0c00e #201 Hardware name: Renesas SMARC EVK based on r9a07g043f01 (DT) epc : __memset+0x60/0x100 ra : __dma_alloc_from_coherent+0x150/0x17a epc : ffffffff8062d2bc ra : ffffffff80053a94 sp : ffffffc60000ba20 gp : ffffffff812e9938 tp : ffffffd601920000 t0 : ffffffc6000d0000 t1 : 0000000000000000 t2 : ffffffffe9600000 s0 : ffffffc60000baa0 s1 : ffffffc6000d0000 a0 : ffffffc6000d0000 a1 : 0000000000000000 a2 : 0000000000001000 a3 : ffffffc6000d1000 a4 : 0000000000000000 a5 : 0000000000000000 a6 : ffffffd601adacc0 a7 : ffffffd601a841a8 s2 : ffffffd6018573c0 s3 : 0000000000001000 s4 : ffffffd6019541e0 s5 : 0000000200000022 s6 : ffffffd6018f8410 s7 : ffffffd6018573e8 s8 : 0000000000000001 s9 : 0000000000000001 s10: 0000000000000010 s11: 0000000000000000 t3 : 0000000000000000 t4 : ffffffffdefe62d1 t5 : 000000001cd6a3a9 t6 : ffffffd601b2aad6 status: 0000000200000120 badaddr: ffffffc6000d0000 cause: 0000000000000007 [<ffffffff8062d2bc>] __memset+0x60/0x100 [<ffffffff80053e1a>] dma_alloc_from_global_coherent+0x1c/0x28 [<ffffffff80053056>] dma_direct_alloc+0x98/0x112 [<ffffffff8005238c>] dma_alloc_attrs+0x78/0x86 [<ffffffff8035fdb4>] rz_dmac_probe+0x3f6/0x50a [<ffffffff803a0694>] platform_probe+0x4c/0x8a If CONFIG_DMA_GLOBAL_POOL=y, the reserved_mem structure passed to rmem_dma_setup() is saved for later use, by saving the passed pointer. However, when dma_init_reserved_memory() is called later, the pointer has become stale, causing a crash. E.g. in the RZ/Five case, the referenced memory now contains the reserved_mem structure for the "mmode_resv0@30000" node (with base 0x30000 and size 0x10000), instead of the correct "pma_resv0@58000000" node (with base 0x58000000 and size 0x8000000). Fix this by saving the needed reserved_mem structure's contents instead. Fixes: 8a6e02d0c00e7b62 ("of: reserved_mem: Restructure how the reserved memory regions are processed") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Oreoluwa Babatunde <quic_obabatun@quicinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-12-15dma-mapping: clear dev->dma_mem to NULL after freeing itJoakim Zhang
Reproduced with below sequence: dma_declare_coherent_memory()->dma_release_coherent_memory() ->dma_declare_coherent_memory()->"return -EBUSY" error It will return -EBUSY from the dma_assign_coherent_memory() in dma_declare_coherent_memory(), the reason is that dev->dma_mem pointer has not been set to NULL after it's freed. Fixes: cf65a0f6f6ff ("dma-mapping: move all DMA mapping code to kernel/dma") Signed-off-by: Joakim Zhang <joakim.zhang@cixtech.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2022-06-24dma-mapping: Add dma_release_coherent_memory to DMA APIMark-PK Tsai
Add dma_release_coherent_memory to DMA API to allow dma user call it to release dev->dma_mem when the device is removed. Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Acked-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220422062436.14384-2-mark-pk.tsai@mediatek.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
2021-10-27dma-mapping: use 'bitmap_zalloc()' when applicableChristophe JAILLET
'dma_mem->bitmap' is a bitmap. So use 'bitmap_zalloc()' to simplify code, improve the semantic and avoid some open-coded arithmetic in allocator arguments. Also change the corresponding 'kfree()' into 'bitmap_free()' to keep consistency. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-08-19dma-mapping: make the global coherent pool conditionalChristoph Hellwig
Only build the code to support the global coherent pool if support for it is enabled. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Dillon Min <dillon.minfei@gmail.com>
2021-08-18dma-mapping: add a dma_init_global_coherent helperChristoph Hellwig
Add a new helper to initialize the global coherent pool. This both cleans up the existing initialization which indirects through the reserved_mem_ops that are normally only used for struct device, and also allows using the global pool for non-devicetree architectures. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Dillon Min <dillon.minfei@gmail.com>
2021-08-18dma-mapping: simplify dma_init_coherent_memoryChristoph Hellwig
Return the allocated dma_coherent_mem structure, set the use_dma_pfn_offset and print the failure warning inside of dma_init_coherent_memory instead of leaving that to the callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Dillon Min <dillon.minfei@gmail.com>
2021-08-18dma-mapping: allow using the global coherent pool for !ARMChristoph Hellwig
Switch an ifdef so that the global coherent pool is initialized for any architecture that selects the DMA_GLOBAL_POOL symbol insted of hardcoding ARM. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Dillon Min <dillon.minfei@gmail.com>
2021-06-22dma-mapping: remove a trailing spaceZhen Lei
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-10-06dma-mapping: split <linux/dma-mapping.h>Christoph Hellwig
Split out all the bits that are purely for dma_map_ops implementations and related code into a new <linux/dma-map-ops.h> header so that they don't get pulled into all the drivers. That also means the architecture specific <asm/dma-mapping.h> is not pulled in by <linux/dma-mapping.h> any more, which leads to a missing includes that were pulled in by the x86 or arm versions in a few not overly portable drivers. Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-09-17dma-mapping: introduce DMA range map, supplanting dma_pfn_offsetJim Quinlan
The new field 'dma_range_map' in struct device is used to facilitate the use of single or multiple offsets between mapping regions of cpu addrs and dma addrs. It subsumes the role of "dev->dma_pfn_offset" which was only capable of holding a single uniform offset and had no region bounds checking. The function of_dma_get_range() has been modified so that it takes a single argument -- the device node -- and returns a map, NULL, or an error code. The map is an array that holds the information regarding the DMA regions. Each range entry contains the address offset, the cpu_start address, the dma_start address, and the size of the region. of_dma_configure() is the typical manner to set range offsets but there are a number of ad hoc assignments to "dev->dma_pfn_offset" in the kernel driver code. These cases now invoke the function dma_direct_set_offset(dev, cpu_addr, dma_addr, size). Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com> [hch: various interface cleanups] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org> Tested-by: Nathan Chancellor <natechancellor@gmail.com>
2020-09-11dma-mapping: move the dma_declare_coherent_memory documentationChristoph Hellwig
dma_declare_coherent_memory should not be in a DMA API guide aimed at driver writers (that is consumers of the API). Move it to a comment near the function instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2020-03-16dma-coherent: fix integer overflow in the reserved-memory dma allocationKevin Grandemange
pageno is an int and the PAGE_SHIFT shift is done on an int, overflowing if the memory is bigger than 2G This can be reproduced using for example a reserved-memory of 4G reserved-memory { #address-cells = <2>; #size-cells = <2>; ranges; reserved_dma: buffer@0 { compatible = "shared-dma-pool"; no-map; reg = <0x5 0x00000000 0x1 0x0>; }; }; Signed-off-by: Kevin Grandemange <kevin.grandemange@allegrodvt.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-10-30dma-mapping: fix handling of dma-ranges for reserved memory (again)Vladimir Murzin
Daniele reported that issue previously fixed in c41f9ea998f3 ("drivers: dma-coherent: Account dma_pfn_offset when used with device tree") reappear shortly after 43fc509c3efb ("dma-coherent: introduce interface for default DMA pool") where fix was accidentally dropped. Lets put fix back in place and respect dma-ranges for reserved memory. Fixes: 43fc509c3efb ("dma-coherent: introduce interface for default DMA pool") Reported-by: Daniele Alessandrelli <daniele.alessandrelli@gmail.com> Tested-by: Daniele Alessandrelli <daniele.alessandrelli@gmail.com> Tested-by: Alexandre Torgue <alexandre.torgue@st.com> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-04dma-mapping: remove the dma_declare_coherent_memory exportChristoph Hellwig
dma_declare_coherent_memory is something that the platform setup code (which pretty much means the device tree these days) need to do so that drivers can use the memory as declared by the platform. Drivers themselves have no business calling this function. Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-04dma-mapping: remove the dma_mmap_from_dev_coherent exportChristoph Hellwig
dma_mmap_from_dev_coherent is only used by dma_map_ops instances, none of which is modular. Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-09-04dma-mapping: remove dma_release_declared_memoryChristoph Hellwig
This function is entirely unused given that declared memory is generally provided by platform setup code. Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-02-20dma-mapping: remove the DMA_MEMORY_EXCLUSIVE flagChristoph Hellwig
All users of dma_declare_coherent want their allocations to be exclusive, so default to exclusive allocations. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-20dma-mapping: remove dma_mark_declared_memory_occupiedChristoph Hellwig
This API is not used anywhere, so remove it. Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-02-13dma-mapping: remove an incorrect __iommem annotationChristoph Hellwig
memmap return a regular void pointer, not and __iomem one. Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-01-04dma-mapping: remove a few unused exportsChristoph Hellwig
Now that the slow path DMA API calls are implemented out of line a few helpers only used by them don't need to be exported anymore. Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-06-14dma-mapping: move all DMA mapping code to kernel/dmaChristoph Hellwig
Currently the code is split over various files with dma- prefixes in the lib/ and drives/base directories, and the number of files keeps growing. Move them into a single directory to keep the code together and remove the file name prefixes. To match the irq infrastructure this directory is placed under the kernel/ directory. Signed-off-by: Christoph Hellwig <hch@lst.de>