| /* |
| * Copyright © 2014 Intel Corporation |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| * IN THE SOFTWARE. |
| * |
| */ |
| |
| #include <linux/mm.h> |
| #include <linux/io-mapping.h> |
| |
| |
| #include "i915_drv.h" |
| |
| #define EXPECTED_FLAGS (VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP) |
| |
| #define use_dma(io) ((io) != -1) |
| |
| /** |
| * remap_io_sg - remap an IO mapping to userspace |
| * @vma: user vma to map to |
| * @addr: target user address to start at |
| * @size: size of map area |
| * @sgl: Start sg entry |
| * @iobase: Use stored dma address offset by this address or pfn if -1 |
| * |
| * Note: this is only safe if the mm semaphore is held when called. |
| */ |
| int remap_io_sg(struct vm_area_struct *vma, |
| unsigned long addr, unsigned long size, |
| struct scatterlist *sgl, resource_size_t iobase) |
| { |
| unsigned long pfn, len, remapped = 0; |
| int err; |
| |
| /* We rely on prevalidation of the io-mapping to skip track_pfn(). */ |
| GEM_BUG_ON((vma->vm_flags & EXPECTED_FLAGS) != EXPECTED_FLAGS); |
| |
| if (!use_dma(iobase)) |
| flush_cache_range(vma, addr, size); |
| |
| do { |
| if (use_dma(iobase)) { |
| if (!sg_dma_len(sgl)) |
| break; |
| pfn = (sg_dma_address(sgl) + iobase) >> PAGE_SHIFT; |
| len = sg_dma_len(sgl); |
| } else { |
| pfn = page_to_pfn(sg_page(sgl)); |
| len = sgl->length; |
| } |
| |
| err = remap_pfn_range(vma, addr + remapped, pfn, len, |
| vma->vm_page_prot); |
| if (err) |
| break; |
| remapped += len; |
| } while ((sgl = __sg_next(sgl))); |
| |
| if (err) |
| zap_vma_ptes(vma, addr, remapped); |
| return err; |
| } |