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164 lines
3.9 KiB
164 lines
3.9 KiB
/* |
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* arch/sh/mm/mmap.c |
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* |
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* Copyright (C) 2008 - 2009 Paul Mundt |
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* |
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* This file is subject to the terms and conditions of the GNU General Public |
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* License. See the file "COPYING" in the main directory of this archive |
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* for more details. |
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*/ |
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#include <linux/io.h> |
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#include <linux/mm.h> |
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#include <linux/sched/mm.h> |
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#include <linux/mman.h> |
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#include <linux/module.h> |
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#include <asm/page.h> |
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#include <asm/processor.h> |
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unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */ |
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EXPORT_SYMBOL(shm_align_mask); |
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#ifdef CONFIG_MMU |
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/* |
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* To avoid cache aliases, we map the shared page with same color. |
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*/ |
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static inline unsigned long COLOUR_ALIGN(unsigned long addr, |
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unsigned long pgoff) |
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{ |
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unsigned long base = (addr + shm_align_mask) & ~shm_align_mask; |
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unsigned long off = (pgoff << PAGE_SHIFT) & shm_align_mask; |
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return base + off; |
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} |
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unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, |
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unsigned long len, unsigned long pgoff, unsigned long flags) |
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{ |
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struct mm_struct *mm = current->mm; |
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struct vm_area_struct *vma; |
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int do_colour_align; |
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struct vm_unmapped_area_info info; |
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if (flags & MAP_FIXED) { |
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/* We do not accept a shared mapping if it would violate |
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* cache aliasing constraints. |
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*/ |
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if ((flags & MAP_SHARED) && |
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((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask)) |
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return -EINVAL; |
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return addr; |
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} |
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if (unlikely(len > TASK_SIZE)) |
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return -ENOMEM; |
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do_colour_align = 0; |
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if (filp || (flags & MAP_SHARED)) |
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do_colour_align = 1; |
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if (addr) { |
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if (do_colour_align) |
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addr = COLOUR_ALIGN(addr, pgoff); |
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else |
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addr = PAGE_ALIGN(addr); |
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vma = find_vma(mm, addr); |
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if (TASK_SIZE - len >= addr && |
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(!vma || addr + len <= vm_start_gap(vma))) |
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return addr; |
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} |
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info.flags = 0; |
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info.length = len; |
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info.low_limit = TASK_UNMAPPED_BASE; |
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info.high_limit = TASK_SIZE; |
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info.align_mask = do_colour_align ? (PAGE_MASK & shm_align_mask) : 0; |
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info.align_offset = pgoff << PAGE_SHIFT; |
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return vm_unmapped_area(&info); |
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} |
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unsigned long |
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arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, |
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const unsigned long len, const unsigned long pgoff, |
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const unsigned long flags) |
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{ |
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struct vm_area_struct *vma; |
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struct mm_struct *mm = current->mm; |
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unsigned long addr = addr0; |
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int do_colour_align; |
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struct vm_unmapped_area_info info; |
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if (flags & MAP_FIXED) { |
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/* We do not accept a shared mapping if it would violate |
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* cache aliasing constraints. |
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*/ |
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if ((flags & MAP_SHARED) && |
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((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask)) |
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return -EINVAL; |
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return addr; |
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} |
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if (unlikely(len > TASK_SIZE)) |
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return -ENOMEM; |
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do_colour_align = 0; |
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if (filp || (flags & MAP_SHARED)) |
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do_colour_align = 1; |
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/* requesting a specific address */ |
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if (addr) { |
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if (do_colour_align) |
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addr = COLOUR_ALIGN(addr, pgoff); |
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else |
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addr = PAGE_ALIGN(addr); |
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vma = find_vma(mm, addr); |
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if (TASK_SIZE - len >= addr && |
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(!vma || addr + len <= vm_start_gap(vma))) |
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return addr; |
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} |
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info.flags = VM_UNMAPPED_AREA_TOPDOWN; |
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info.length = len; |
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info.low_limit = PAGE_SIZE; |
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info.high_limit = mm->mmap_base; |
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info.align_mask = do_colour_align ? (PAGE_MASK & shm_align_mask) : 0; |
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info.align_offset = pgoff << PAGE_SHIFT; |
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addr = vm_unmapped_area(&info); |
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/* |
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* A failed mmap() very likely causes application failure, |
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* so fall back to the bottom-up function here. This scenario |
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* can happen with large stack limits and large mmap() |
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* allocations. |
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*/ |
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if (addr & ~PAGE_MASK) { |
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VM_BUG_ON(addr != -ENOMEM); |
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info.flags = 0; |
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info.low_limit = TASK_UNMAPPED_BASE; |
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info.high_limit = TASK_SIZE; |
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addr = vm_unmapped_area(&info); |
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} |
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return addr; |
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} |
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#endif /* CONFIG_MMU */ |
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/* |
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* You really shouldn't be using read() or write() on /dev/mem. This |
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* might go away in the future. |
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*/ |
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int valid_phys_addr_range(phys_addr_t addr, size_t count) |
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{ |
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if (addr < __MEMORY_START) |
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return 0; |
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if (addr + count > __pa(high_memory)) |
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return 0; |
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return 1; |
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} |
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int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) |
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{ |
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return 1; |
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}
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