Thomas Gleixner | d2912cb | 2019-06-04 10:11:33 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Vineet Gupta | 5bba49f | 2013-05-09 19:20:43 +0530 | [diff] [blame] | 2 | /* |
| 3 | * ARC700 mmap |
| 4 | * |
| 5 | * (started from arm version - for VIPT alias handling) |
| 6 | * |
| 7 | * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com) |
Vineet Gupta | 5bba49f | 2013-05-09 19:20:43 +0530 | [diff] [blame] | 8 | */ |
| 9 | |
| 10 | #include <linux/fs.h> |
| 11 | #include <linux/mm.h> |
| 12 | #include <linux/mman.h> |
Ingo Molnar | 0104260 | 2017-02-08 18:51:31 +0100 | [diff] [blame] | 13 | #include <linux/sched/mm.h> |
| 14 | |
Vineet Gupta | 5bba49f | 2013-05-09 19:20:43 +0530 | [diff] [blame] | 15 | #include <asm/cacheflush.h> |
| 16 | |
| 17 | #define COLOUR_ALIGN(addr, pgoff) \ |
| 18 | ((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) + \ |
| 19 | (((pgoff) << PAGE_SHIFT) & (SHMLBA - 1))) |
| 20 | |
| 21 | /* |
| 22 | * Ensure that shared mappings are correctly aligned to |
| 23 | * avoid aliasing issues with VIPT caches. |
| 24 | * We need to ensure that |
| 25 | * a specific page of an object is always mapped at a multiple of |
| 26 | * SHMLBA bytes. |
| 27 | */ |
| 28 | unsigned long |
| 29 | arch_get_unmapped_area(struct file *filp, unsigned long addr, |
| 30 | unsigned long len, unsigned long pgoff, unsigned long flags) |
| 31 | { |
| 32 | struct mm_struct *mm = current->mm; |
| 33 | struct vm_area_struct *vma; |
| 34 | int do_align = 0; |
| 35 | int aliasing = cache_is_vipt_aliasing(); |
| 36 | struct vm_unmapped_area_info info; |
| 37 | |
| 38 | /* |
| 39 | * We only need to do colour alignment if D cache aliases. |
| 40 | */ |
| 41 | if (aliasing) |
| 42 | do_align = filp || (flags & MAP_SHARED); |
| 43 | |
| 44 | /* |
| 45 | * We enforce the MAP_FIXED case. |
| 46 | */ |
| 47 | if (flags & MAP_FIXED) { |
| 48 | if (aliasing && flags & MAP_SHARED && |
| 49 | (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)) |
| 50 | return -EINVAL; |
| 51 | return addr; |
| 52 | } |
| 53 | |
| 54 | if (len > TASK_SIZE) |
| 55 | return -ENOMEM; |
| 56 | |
| 57 | if (addr) { |
| 58 | if (do_align) |
| 59 | addr = COLOUR_ALIGN(addr, pgoff); |
| 60 | else |
| 61 | addr = PAGE_ALIGN(addr); |
| 62 | |
| 63 | vma = find_vma(mm, addr); |
| 64 | if (TASK_SIZE - len >= addr && |
Hugh Dickins | 1be7107 | 2017-06-19 04:03:24 -0700 | [diff] [blame] | 65 | (!vma || addr + len <= vm_start_gap(vma))) |
Vineet Gupta | 5bba49f | 2013-05-09 19:20:43 +0530 | [diff] [blame] | 66 | return addr; |
| 67 | } |
| 68 | |
| 69 | info.flags = 0; |
| 70 | info.length = len; |
| 71 | info.low_limit = mm->mmap_base; |
| 72 | info.high_limit = TASK_SIZE; |
| 73 | info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0; |
| 74 | info.align_offset = pgoff << PAGE_SHIFT; |
| 75 | return vm_unmapped_area(&info); |
| 76 | } |