kernel/arch/arm64/mm/dma-mapping.c, branch linux-6.2.y

Revert "arm64: dma: Drop cache invalidation from arch_dma_prep_coherent()"

2022-12-06T17:30:39Z

This reverts commit c44094eee32f32f175aadc0efcac449d99b1bbf7. Although the semantics of the DMA API require only a clean operation here, it turns out that the Qualcomm 'qcom_q6v5_mss' remoteproc driver (ab)uses the DMA API for transferring the modem firmware to the secure world via calls to Trustzone [1]. Once the firmware buffer has changed hands, _any_ access from the non-secure side (i.e. Linux) will be detected on the bus and result in a full system reset [2]. Although this is possible even with this revert in place (due to speculative reads via the cacheable linear alias of memory), anecdotally the problem occurs considerably more frequently when the lines have not been invalidated, assumedly due to some micro-architectural interactions with the cache hierarchy. Revert the offending change for now, along with a comment, so that the Qualcomm developers have time to fix the driver [3] to use a firmware buffer which does not have a cacheable alias in the linear map. Link: https://lore.kernel.org/r/20221114110329.68413-1-manivannan.sadhasivam@linaro.org [1] Link: https://lore.kernel.org/r/CAMi1Hd3H2k1J8hJ6e-Miy5+nVDNzv6qQ3nN-9929B0GbHJkXEg@mail.gmail.com/ [2] Link: https://lore.kernel.org/r/20221206092152.GD15486@thinkpad [2] Reported-by: Amit Pundir Reported-by: Manivannan Sadhasivam Cc: Thorsten Leemhuis Cc: Sibi Sankar Signed-off-by: Will Deacon Acked-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20221206103403.646-1-will@kernel.org Signed-off-by: Catalin Marinas

Merge tag 'iommu-updates-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

2022-10-10T20:20:53Z

Pull iommu updates from Joerg Roedel: - remove the bus_set_iommu() interface which became unnecesary because of IOMMU per-device probing - make the dma-iommu.h header private - Intel VT-d changes from Lu Baolu: - Decouple PASID and PRI from SVA - Add ESRTPS & ESIRTPS capability check - Cleanups - Apple DART support for the M1 Pro/MAX SOCs - support for AMD IOMMUv2 page-tables for the DMA-API layer. The v2 page-tables are compatible with the x86 CPU page-tables. Using them for DMA-API prepares support for hardware-assisted IOMMU virtualization - support for MT6795 Helio X10 M4Us in the Mediatek IOMMU driver - some smaller fixes and cleanups * tag 'iommu-updates-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (59 commits) iommu/vt-d: Avoid unnecessary global DMA cache invalidation iommu/vt-d: Avoid unnecessary global IRTE cache invalidation iommu/vt-d: Rename cap_5lp_support to cap_fl5lp_support iommu/vt-d: Remove pasid_set_eafe() iommu/vt-d: Decouple PASID & PRI enabling from SVA iommu/vt-d: Remove unnecessary SVA data accesses in page fault path dt-bindings: iommu: arm,smmu-v3: Relax order of interrupt names iommu: dart: Support t6000 variant iommu/io-pgtable-dart: Add DART PTE support for t6000 iommu/io-pgtable: Add DART subpage protection support iommu/io-pgtable: Move Apple DART support to its own file iommu/mediatek: Add support for MT6795 Helio X10 M4Us iommu/mediatek: Introduce new flag TF_PORT_TO_ADDR_MT8173 dt-bindings: mediatek: Add bindings for MT6795 M4U iommu/iova: Fix module config properly iommu/amd: Fix sparse warning iommu/amd: Remove outdated comment iommu/amd: Free domain ID after domain_flush_pages iommu/amd: Free domain id in error path iommu/virtio: Fix compile error with viommu_capable() ...

arm64: dma: Drop cache invalidation from arch_dma_prep_coherent()

2022-09-22T14:09:31Z

arch_dma_prep_coherent() is called when preparing a non-cacheable region for a consistent DMA buffer allocation. Since the buffer pages may previously have been written via a cacheable mapping and consequently allocated as dirty cachelines, the purpose of this function is to remove these dirty lines from the cache, writing them back so that the non-coherent device is able to see them. On arm64, this operation can be achieved with a clean to the point of coherency; a subsequent invalidation is not required and serves little purpose in the presence of a cacheable alias (e.g. the linear map), since clean lines can be speculatively fetched back into the cache after the invalidation operation has completed. Relax the cache maintenance in arch_dma_prep_coherent() so that only a clean, and not a clean-and-invalidate operation is performed. Cc: Mark Rutland Cc: Robin Murphy Cc: Christoph Hellwig Cc: Ard Biesheuvel Signed-off-by: Will Deacon Reviewed-by: Catalin Marinas Link: https://lore.kernel.org/r/20220823122111.17439-1-will@kernel.org Signed-off-by: Catalin Marinas

iommu/dma: Move public interfaces to linux/iommu.h

2022-09-07T12:47:00Z

The iommu-dma layer is now mostly encapsulated by iommu_dma_ops, with only a couple more public interfaces left pertaining to MSI integration. Since these depend on the main IOMMU API header anyway, move their declarations there, taking the opportunity to update the half-baked comments to proper kerneldoc along the way. Signed-off-by: Robin Murphy Acked-by: Catalin Marinas Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/9cd99738f52094e6bed44bfee03fa4f288d20695.1660668998.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel

arm64: mm: Remove assembly DMA cache maintenance wrappers

2022-07-05T12:06:31Z

Remove the __dma_{flush,map,unmap}_area assembly wrappers and call the appropriate cache maintenance functions directly from the DMA mapping callbacks. Reviewed-by: Catalin Marinas Reviewed-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20220610151228.4562-3-will@kernel.org Signed-off-by: Will Deacon

arm/xen: Introduce xen_setup_dma_ops()

2022-06-06T06:54:33Z

This patch introduces new helper and places it in new header. The helper's purpose is to assign any Xen specific DMA ops in a single place. For now, we deal with xen-swiotlb DMA ops only. The one of the subsequent commits in current series will add xen-grant DMA ops case. Also re-use the xen_swiotlb_detect() check on Arm32. Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Stefano Stabellini [For arm64] Acked-by: Catalin Marinas Link: https://lore.kernel.org/r/1654197833-25362-2-git-send-email-olekstysh@gmail.com Signed-off-by: Juergen Gross

iommu/dma: Pass address limit rather than size to iommu_setup_dma_ops()

2021-06-25T13:02:43Z

Passing a 64-bit address width to iommu_setup_dma_ops() is valid on virtual platforms, but isn't currently possible. The overflow check in iommu_dma_init_domain() prevents this even when @dma_base isn't 0. Pass a limit address instead of a size, so callers don't have to fake a size to work around the check. The base and limit parameters are being phased out, because: * they are redundant for x86 callers. dma-iommu already reserves the first page, and the upper limit is already in domain->geometry. * they can now be obtained from dev->dma_range_map on Arm. But removing them on Arm isn't completely straightforward so is left for future work. As an intermediate step, simplify the x86 callers by passing dummy limits. Signed-off-by: Jean-Philippe Brucker Reviewed-by: Eric Auger Reviewed-by: Robin Murphy Link: https://lore.kernel.org/r/20210618152059.1194210-5-jean-philippe@linaro.org Signed-off-by: Joerg Roedel

xen/arm: introduce XENFEAT_direct_mapped and XENFEAT_not_direct_mapped

2021-04-23T09:33:50Z

Newer Xen versions expose two Xen feature flags to tell us if the domain is directly mapped or not. Only when a domain is directly mapped it makes sense to enable swiotlb-xen on ARM. Introduce a function on ARM to check the new Xen feature flags and also to deal with the legacy case. Call the function xen_swiotlb_detect. Signed-off-by: Stefano Stabellini Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/20210319200140.12512-1-sstabellini@kernel.org Signed-off-by: Juergen Gross

dma-mapping: merge into

2020-10-06T05:07:06Z

Move more nitty gritty DMA implementation details into the common internal header. Signed-off-by: Christoph Hellwig

dma-mapping: split

2020-10-06T05:07:03Z

Split out all the bits that are purely for dma_map_ops implementations and related code into a new header so that they don't get pulled into all the drivers. That also means the architecture specific is not pulled in by 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