1 /* 2 * ARC700 mmap 3 * 4 * (started from arm version - for VIPT alias handling) 5 * 6 * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com) 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12 13 #include <linux/fs.h> 14 #include <linux/mm.h> 15 #include <linux/mman.h> 16 #include <linux/sched/mm.h> 17 18 #include <asm/cacheflush.h> 19 20 #define COLOUR_ALIGN(addr, pgoff) \ 21 ((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) + \ 22 (((pgoff) << PAGE_SHIFT) & (SHMLBA - 1))) 23 24 /* 25 * Ensure that shared mappings are correctly aligned to 26 * avoid aliasing issues with VIPT caches. 27 * We need to ensure that 28 * a specific page of an object is always mapped at a multiple of 29 * SHMLBA bytes. 30 */ 31 unsigned long 32 arch_get_unmapped_area(struct file *filp, unsigned long addr, 33 unsigned long len, unsigned long pgoff, unsigned long flags) 34 { 35 struct mm_struct *mm = current->mm; 36 struct vm_area_struct *vma; 37 int do_align = 0; 38 int aliasing = cache_is_vipt_aliasing(); 39 struct vm_unmapped_area_info info; 40 41 /* 42 * We only need to do colour alignment if D cache aliases. 43 */ 44 if (aliasing) 45 do_align = filp || (flags & MAP_SHARED); 46 47 /* 48 * We enforce the MAP_FIXED case. 49 */ 50 if (flags & MAP_FIXED) { 51 if (aliasing && flags & MAP_SHARED && 52 (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)) 53 return -EINVAL; 54 return addr; 55 } 56 57 if (len > TASK_SIZE) 58 return -ENOMEM; 59 60 if (addr) { 61 if (do_align) 62 addr = COLOUR_ALIGN(addr, pgoff); 63 else 64 addr = PAGE_ALIGN(addr); 65 66 vma = find_vma(mm, addr); 67 if (TASK_SIZE - len >= addr && 68 (!vma || addr + len <= vma->vm_start)) 69 return addr; 70 } 71 72 info.flags = 0; 73 info.length = len; 74 info.low_limit = mm->mmap_base; 75 info.high_limit = TASK_SIZE; 76 info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0; 77 info.align_offset = pgoff << PAGE_SHIFT; 78 return vm_unmapped_area(&info); 79 } 80