1/* 2 * arch/sh/mm/mmap.c 3 * 4 * Copyright (C) 2008 - 2009 Paul Mundt 5 * 6 * This file is subject to the terms and conditions of the GNU General Public 7 * License. See the file "COPYING" in the main directory of this archive 8 * for more details. 9 */ 10#include <linux/io.h> 11#include <linux/mm.h> 12#include <linux/sched/mm.h> 13#include <linux/mman.h> 14#include <linux/module.h> 15#include <asm/page.h> 16#include <asm/processor.h> 17 18unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */ 19EXPORT_SYMBOL(shm_align_mask); 20 21#ifdef CONFIG_MMU 22/* 23 * To avoid cache aliases, we map the shared page with same color. 24 */ 25static inline unsigned long COLOUR_ALIGN(unsigned long addr, 26 unsigned long pgoff) 27{ 28 unsigned long base = (addr + shm_align_mask) & ~shm_align_mask; 29 unsigned long off = (pgoff << PAGE_SHIFT) & shm_align_mask; 30 31 return base + off; 32} 33 34unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, 35 unsigned long len, unsigned long pgoff, unsigned long flags) 36{ 37 struct mm_struct *mm = current->mm; 38 struct vm_area_struct *vma; 39 int do_colour_align; 40 struct vm_unmapped_area_info info; 41 42 if (flags & MAP_FIXED) { 43 /* We do not accept a shared mapping if it would violate 44 * cache aliasing constraints. 45 */ 46 if ((flags & MAP_SHARED) && 47 ((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask)) 48 return -EINVAL; 49 return addr; 50 } 51 52 if (unlikely(len > TASK_SIZE)) 53 return -ENOMEM; 54 55 do_colour_align = 0; 56 if (filp || (flags & MAP_SHARED)) 57 do_colour_align = 1; 58 59 if (addr) { 60 if (do_colour_align) 61 addr = COLOUR_ALIGN(addr, pgoff); 62 else 63 addr = PAGE_ALIGN(addr); 64 65 vma = find_vma(mm, addr); 66 if (TASK_SIZE - len >= addr && 67 (!vma || addr + len <= vm_start_gap(vma))) 68 return addr; 69 } 70 71 info.flags = 0; 72 info.length = len; 73 info.low_limit = TASK_UNMAPPED_BASE; 74 info.high_limit = TASK_SIZE; 75 info.align_mask = do_colour_align ? (PAGE_MASK & shm_align_mask) : 0; 76 info.align_offset = pgoff << PAGE_SHIFT; 77 return vm_unmapped_area(&info); 78} 79 80unsigned long 81arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, 82 const unsigned long len, const unsigned long pgoff, 83 const unsigned long flags) 84{ 85 struct vm_area_struct *vma; 86 struct mm_struct *mm = current->mm; 87 unsigned long addr = addr0; 88 int do_colour_align; 89 struct vm_unmapped_area_info info; 90 91 if (flags & MAP_FIXED) { 92 /* We do not accept a shared mapping if it would violate 93 * cache aliasing constraints. 94 */ 95 if ((flags & MAP_SHARED) && 96 ((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask)) 97 return -EINVAL; 98 return addr; 99 } 100 101 if (unlikely(len > TASK_SIZE)) 102 return -ENOMEM; 103 104 do_colour_align = 0; 105 if (filp || (flags & MAP_SHARED)) 106 do_colour_align = 1; 107 108 /* requesting a specific address */ 109 if (addr) { 110 if (do_colour_align) 111 addr = COLOUR_ALIGN(addr, pgoff); 112 else 113 addr = PAGE_ALIGN(addr); 114 115 vma = find_vma(mm, addr); 116 if (TASK_SIZE - len >= addr && 117 (!vma || addr + len <= vm_start_gap(vma))) 118 return addr; 119 } 120 121 info.flags = VM_UNMAPPED_AREA_TOPDOWN; 122 info.length = len; 123 info.low_limit = PAGE_SIZE; 124 info.high_limit = mm->mmap_base; 125 info.align_mask = do_colour_align ? (PAGE_MASK & shm_align_mask) : 0; 126 info.align_offset = pgoff << PAGE_SHIFT; 127 addr = vm_unmapped_area(&info); 128 129 /* 130 * A failed mmap() very likely causes application failure, 131 * so fall back to the bottom-up function here. This scenario 132 * can happen with large stack limits and large mmap() 133 * allocations. 134 */ 135 if (addr & ~PAGE_MASK) { 136 VM_BUG_ON(addr != -ENOMEM); 137 info.flags = 0; 138 info.low_limit = TASK_UNMAPPED_BASE; 139 info.high_limit = TASK_SIZE; 140 addr = vm_unmapped_area(&info); 141 } 142 143 return addr; 144} 145#endif /* CONFIG_MMU */ 146 147/* 148 * You really shouldn't be using read() or write() on /dev/mem. This 149 * might go away in the future. 150 */ 151int valid_phys_addr_range(phys_addr_t addr, size_t count) 152{ 153 if (addr < __MEMORY_START) 154 return 0; 155 if (addr + count > __pa(high_memory)) 156 return 0; 157 158 return 1; 159} 160 161int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) 162{ 163 return 1; 164} 165