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b12d691ea5
remap_io_sg claims that the pgprot is pre-verified using an io_mapping, but actually does not get passed an io_mapping and just uses the pgprot in the VMA. Remove the apply_to_page_range abuse and just loop over remap_pfn_range for each segment. Note: this could use io_mapping_map_user by passing an iomap to remap_io_sg if the maintainers can verify that the pgprot in the iomap in the only caller is indeed the desired one here. Link: https://lkml.kernel.org/r/20210326055505.1424432-5-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
79 lines
2.4 KiB
C
79 lines
2.4 KiB
C
/*
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* Copyright © 2014 Intel Corporation
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice (including the next
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* paragraph) shall be included in all copies or substantial portions of the
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* Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*
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*/
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#include <linux/mm.h>
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#include <linux/io-mapping.h>
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#include "i915_drv.h"
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#define EXPECTED_FLAGS (VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP)
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#define use_dma(io) ((io) != -1)
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/**
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* remap_io_sg - remap an IO mapping to userspace
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* @vma: user vma to map to
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* @addr: target user address to start at
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* @size: size of map area
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* @sgl: Start sg entry
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* @iobase: Use stored dma address offset by this address or pfn if -1
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*
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* Note: this is only safe if the mm semaphore is held when called.
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*/
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int remap_io_sg(struct vm_area_struct *vma,
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unsigned long addr, unsigned long size,
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struct scatterlist *sgl, resource_size_t iobase)
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{
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unsigned long pfn, len, remapped = 0;
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int err;
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/* We rely on prevalidation of the io-mapping to skip track_pfn(). */
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GEM_BUG_ON((vma->vm_flags & EXPECTED_FLAGS) != EXPECTED_FLAGS);
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if (!use_dma(iobase))
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flush_cache_range(vma, addr, size);
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do {
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if (use_dma(iobase)) {
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if (!sg_dma_len(sgl))
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break;
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pfn = (sg_dma_address(sgl) + iobase) >> PAGE_SHIFT;
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len = sg_dma_len(sgl);
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} else {
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pfn = page_to_pfn(sg_page(sgl));
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len = sgl->length;
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}
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err = remap_pfn_range(vma, addr + remapped, pfn, len,
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vma->vm_page_prot);
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if (err)
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break;
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remapped += len;
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} while ((sgl = __sg_next(sgl)));
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if (err)
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zap_vma_ptes(vma, addr, remapped);
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return err;
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}
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