diff options
Diffstat (limited to 'arch/sh/mm/mmap.c')
| -rw-r--r-- | arch/sh/mm/mmap.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/arch/sh/mm/mmap.c b/arch/sh/mm/mmap.c new file mode 100644 index 000000000..6a1a1297b --- /dev/null +++ b/arch/sh/mm/mmap.c @@ -0,0 +1,164 @@ +/* + * arch/sh/mm/mmap.c + * + * Copyright (C) 2008 - 2009 Paul Mundt + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ +#include <linux/io.h> +#include <linux/mm.h> +#include <linux/sched/mm.h> +#include <linux/mman.h> +#include <linux/module.h> +#include <asm/page.h> +#include <asm/processor.h> + +unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */ +EXPORT_SYMBOL(shm_align_mask); + +#ifdef CONFIG_MMU +/* + * To avoid cache aliases, we map the shared page with same color. + */ +static inline unsigned long COLOUR_ALIGN(unsigned long addr, + unsigned long pgoff) +{ + unsigned long base = (addr + shm_align_mask) & ~shm_align_mask; + unsigned long off = (pgoff << PAGE_SHIFT) & shm_align_mask; + + return base + off; +} + +unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, + unsigned long len, unsigned long pgoff, unsigned long flags) +{ + struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; + int do_colour_align; + struct vm_unmapped_area_info info; + + if (flags & MAP_FIXED) { + /* We do not accept a shared mapping if it would violate + * cache aliasing constraints. + */ + if ((flags & MAP_SHARED) && + ((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask)) + return -EINVAL; + return addr; + } + + if (unlikely(len > TASK_SIZE)) + return -ENOMEM; + + do_colour_align = 0; + if (filp || (flags & MAP_SHARED)) + do_colour_align = 1; + + if (addr) { + if (do_colour_align) + addr = COLOUR_ALIGN(addr, pgoff); + else + addr = PAGE_ALIGN(addr); + + vma = find_vma(mm, addr); + if (TASK_SIZE - len >= addr && + (!vma || addr + len <= vm_start_gap(vma))) + return addr; + } + + info.flags = 0; + info.length = len; + info.low_limit = TASK_UNMAPPED_BASE; + info.high_limit = TASK_SIZE; + info.align_mask = do_colour_align ? (PAGE_MASK & shm_align_mask) : 0; + info.align_offset = pgoff << PAGE_SHIFT; + return vm_unmapped_area(&info); +} + +unsigned long +arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, + const unsigned long len, const unsigned long pgoff, + const unsigned long flags) +{ + struct vm_area_struct *vma; + struct mm_struct *mm = current->mm; + unsigned long addr = addr0; + int do_colour_align; + struct vm_unmapped_area_info info; + + if (flags & MAP_FIXED) { + /* We do not accept a shared mapping if it would violate + * cache aliasing constraints. + */ + if ((flags & MAP_SHARED) && + ((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask)) + return -EINVAL; + return addr; + } + + if (unlikely(len > TASK_SIZE)) + return -ENOMEM; + + do_colour_align = 0; + if (filp || (flags & MAP_SHARED)) + do_colour_align = 1; + + /* requesting a specific address */ + if (addr) { + if (do_colour_align) + addr = COLOUR_ALIGN(addr, pgoff); + else + addr = PAGE_ALIGN(addr); + + vma = find_vma(mm, addr); + if (TASK_SIZE - len >= addr && + (!vma || addr + len <= vm_start_gap(vma))) + return addr; + } + + info.flags = VM_UNMAPPED_AREA_TOPDOWN; + info.length = len; + info.low_limit = PAGE_SIZE; + info.high_limit = mm->mmap_base; + info.align_mask = do_colour_align ? (PAGE_MASK & shm_align_mask) : 0; + info.align_offset = pgoff << PAGE_SHIFT; + addr = vm_unmapped_area(&info); + + /* + * A failed mmap() very likely causes application failure, + * so fall back to the bottom-up function here. This scenario + * can happen with large stack limits and large mmap() + * allocations. + */ + if (addr & ~PAGE_MASK) { + VM_BUG_ON(addr != -ENOMEM); + info.flags = 0; + info.low_limit = TASK_UNMAPPED_BASE; + info.high_limit = TASK_SIZE; + addr = vm_unmapped_area(&info); + } + + return addr; +} +#endif /* CONFIG_MMU */ + +/* + * You really shouldn't be using read() or write() on /dev/mem. This + * might go away in the future. + */ +int valid_phys_addr_range(phys_addr_t addr, size_t count) +{ + if (addr < __MEMORY_START) + return 0; + if (addr + count > __pa(high_memory)) + return 0; + + return 1; +} + +int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) +{ + return 1; +} |