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This fixes a cascade of regressions that originally started with the addition of the ia64 port, but only got fatal once we removed most uses of block layer bounce buffering in Linux 4.18. The reason is that while the original i386/PAE code that was the first architecture that supported > 4GB of memory without an iommu decided to leave bounce buffering to the subsystems, which in those days just mean block and networking as no one else consumer arbitrary userspace memory. Later with ia64, x86_64 and other ports we assumed that either an iommu or something that fakes it up ("software IOTLB" in beautiful Intel speak) is present and that subsystems can rely on that for dealing with addressing limitations in devices. Except that the ARM LPAE scheme that added larger physical address to 32-bit ARM did not follow that scheme and thus only worked by chance and only for block and networking I/O directly to highmem. Long story, short fix - add swiotlb support to arm when build for LPAE platforms, which actuallys turns out to be pretty trivial with the modern dma-direct / swiotlb code to fix the Linux 4.18-ish regression. -----BEGIN PGP SIGNATURE----- iQI/BAABCgApFiEEgdbnc3r/njty3Iq9D55TZVIEUYMFAl1DFj8LHGhjaEBsc3Qu ZGUACgkQD55TZVIEUYPFqg/+Oh62VCFCkIK07NAeTq6EmrfHI8I1Wm/SFWPOOB+a vm7nMcSG3C8K8PRHzGc6Zk3SC1+RrHghcyKw54yLT1Mhroakv6Um7p2y8S3M4tmZ uEg8yYbtzxvuaY9T42s2msZURbBCEELzA2bYbQzgQ1zczRI1zuMI07ssMr91IQ91 HC1OjAUoxUkp/+2uU/X2k6DvPQLSJSyWvKgbi1bjNpE+FRCKJP+2a2K3psBQuDBe aJXiz/kD2L/JNvF/e4c414d5GnGXwtIYs1kbskmnj3LeToS+JjX+6ZcENorpScIP c20s/3H6nsb14TFy548rJUlAHdcd9kOdeTw+0oPUliNLCogGs6FKNU4N5gVAo+bC AWDP0wMHMWkrVz6lQL9PR78IHrHOxFYS5/uHsqqdKo5YTsgaHnwKEiPxX1aiKQ67 ovUrOnGRo4R9Y4YwD+BbHY9qw9jFMqazBdLWMivK5NxqltsahOug8w2emTFfXzQn m4APJYa0RVJA4mkh3ejcci5qHyyzPOjslyIJn7eaJPV2rknkxRn9UngkgJLnzHfc +lKiD1zaRy82nV4auPjYRiOdAoQN40YFB/RT16OVkjkT+jJEE2UAMjqh2SRlRusp Ce8vK7pw6VpDNGJRQveQA+1n9OR/jl0Jf8R7GFRrf9c/bM1J8GErJ6xS/EwNPrgI 5dE= =D6Uy -----END PGP SIGNATURE----- Merge tag 'arm-swiotlb-5.3' of git://git.infradead.org/users/hch/dma-mapping Pull arm swiotlb support from Christoph Hellwig: "This fixes a cascade of regressions that originally started with the addition of the ia64 port, but only got fatal once we removed most uses of block layer bounce buffering in Linux 4.18. The reason is that while the original i386/PAE code that was the first architecture that supported > 4GB of memory without an iommu decided to leave bounce buffering to the subsystems, which in those days just mean block and networking as no one else consumed arbitrary userspace memory. Later with ia64, x86_64 and other ports we assumed that either an iommu or something that fakes it up ("software IOTLB" in beautiful Intel speak) is present and that subsystems can rely on that for dealing with addressing limitations in devices. Except that the ARM LPAE scheme that added larger physical address to 32-bit ARM did not follow that scheme and thus only worked by chance and only for block and networking I/O directly to highmem. Long story, short fix - add swiotlb support to arm when build for LPAE platforms, which actuallys turns out to be pretty trivial with the modern dma-direct / swiotlb code to fix the Linux 4.18-ish regression" * tag 'arm-swiotlb-5.3' of git://git.infradead.org/users/hch/dma-mapping: arm: use swiotlb for bounce buffering on LPAE configs dma-mapping: check pfn validity in dma_common_{mmap,get_sgtable} |
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.. | ||
coherent.c | ||
contiguous.c | ||
debug.c | ||
direct.c | ||
dummy.c | ||
Kconfig | ||
Makefile | ||
mapping.c | ||
remap.c | ||
swiotlb.c | ||
virt.c |