projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| c58305af CW |
1 | /* |
| 2 | * Copyright © 2014 Intel Corporation | |
| 3 | * | |
| 4 | * Permission is hereby granted, free of charge, to any person obtaining a | |
| 5 | * copy of this software and associated documentation files (the "Software"), | |
| 6 | * to deal in the Software without restriction, including without limitation | |
| 7 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, | |
| 8 | * and/or sell copies of the Software, and to permit persons to whom the | |
| 9 | * Software is furnished to do so, subject to the following conditions: | |
| 10 | * | |
| 11 | * The above copyright notice and this permission notice (including the next | |
| 12 | * paragraph) shall be included in all copies or substantial portions of the | |
| 13 | * Software. | |
| 14 | * | |
| 15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
| 16 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
| 17 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
| 18 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
| 19 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
| 20 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | |
| 21 | * IN THE SOFTWARE. | |
| 22 | * | |
| 23 | */ | |
| 24 | ||
| 25 | #include <linux/mm.h> | |
| 26 | #include <linux/io-mapping.h> | |
| 27 | ||
| 28 | #include <asm/pgtable.h> | |
| 29 | ||
| 30 | #include "i915_drv.h" | |
| 31 | ||
| 32 | struct remap_pfn { | |
| 33 | struct mm_struct *mm; | |
| 34 | unsigned long pfn; | |
| 35 | pgprot_t prot; | |
| 36 | }; | |
| 37 | ||
| 38 | static int remap_pfn(pte_t *pte, pgtable_t token, | |
| 39 | unsigned long addr, void *data) | |
| 40 | { | |
| 41 | struct remap_pfn *r = data; | |
| 42 | ||
| 43 | /* Special PTE are not associated with any struct page */ | |
| 44 | set_pte_at(r->mm, addr, pte, pte_mkspecial(pfn_pte(r->pfn, r->prot))); | |
| 45 | r->pfn++; | |
| 46 | ||
| 47 | return 0; | |
| 48 | } | |
| 49 | ||
| 50 | /** | |
| 51 | * remap_io_mapping - remap an IO mapping to userspace | |
| 52 | * @vma: user vma to map to | |
| 53 | * @addr: target user address to start at | |
| 54 | * @pfn: physical address of kernel memory | |
| 55 | * @size: size of map area | |
| 56 | * @iomap: the source io_mapping | |
| 57 | * | |
| 58 | * Note: this is only safe if the mm semaphore is held when called. | |
| 59 | */ | |
| 60 | int remap_io_mapping(struct vm_area_struct *vma, | |
| 61 | unsigned long addr, unsigned long pfn, unsigned long size, | |
| 62 | struct io_mapping *iomap) | |
| 63 | { | |
| 64 | struct remap_pfn r; | |
| 65 | int err; | |
| 66 | ||
| 67 | GEM_BUG_ON((vma->vm_flags & | |
| 68 | (VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP)) != | |
| 69 | (VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP)); | |
| 70 | ||
| 71 | /* We rely on prevalidation of the io-mapping to skip track_pfn(). */ | |
| 72 | r.mm = vma->vm_mm; | |
| 73 | r.pfn = pfn; | |
| 74 | r.prot = __pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) | | |
| 75 | (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK)); | |
| 76 | ||
| 77 | err = apply_to_page_range(r.mm, addr, size, remap_pfn, &r); | |
| 78 | if (unlikely(err)) { | |
| 79 | zap_vma_ptes(vma, addr, (r.pfn - pfn) << PAGE_SHIFT); | |
| 80 | return err; | |
| 81 | } | |
| 82 | ||
| 83 | return 0; | |
| 84 | } |