From 4a4a9be3ebdbf17957d29e3521f328a1145f9431 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Wed, 12 Nov 2008 13:17:38 +0900 Subject: sh: Move arch_get_unmapped_area() in to arch/sh/mm/mmap.c. Now that arch/sh/mm/mmap.c exists, move arch_get_unmapped_area() there. Follows the ARM change. Signed-off-by: Paul Mundt --- arch/sh/mm/mmap.c | 94 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+) (limited to 'arch/sh/mm') diff --git a/arch/sh/mm/mmap.c b/arch/sh/mm/mmap.c index 8837d511710a..931f4d003fa0 100644 --- a/arch/sh/mm/mmap.c +++ b/arch/sh/mm/mmap.c @@ -9,7 +9,101 @@ */ #include #include +#include +#include #include +#include + +#ifdef CONFIG_MMU +unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */ +EXPORT_SYMBOL(shm_align_mask); + +/* + * To avoid cache aliases, we map the shared page with same color. + */ +#define COLOUR_ALIGN(addr, pgoff) \ + ((((addr) + shm_align_mask) & ~shm_align_mask) + \ + (((pgoff) << PAGE_SHIFT) & shm_align_mask)) + +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; + unsigned long start_addr; + int do_colour_align; + + if (flags & MAP_FIXED) { + /* We do not accept a shared mapping if it would violate + * cache aliasing constraints. + */ + if ((flags & MAP_SHARED) && (addr & 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 <= vma->vm_start)) + return addr; + } + + if (len > mm->cached_hole_size) { + start_addr = addr = mm->free_area_cache; + } else { + mm->cached_hole_size = 0; + start_addr = addr = TASK_UNMAPPED_BASE; + } + +full_search: + if (do_colour_align) + addr = COLOUR_ALIGN(addr, pgoff); + else + addr = PAGE_ALIGN(mm->free_area_cache); + + for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { + /* At this point: (!vma || addr < vma->vm_end). */ + if (unlikely(TASK_SIZE - len < addr)) { + /* + * Start a new search - just in case we missed + * some holes. + */ + if (start_addr != TASK_UNMAPPED_BASE) { + start_addr = addr = TASK_UNMAPPED_BASE; + mm->cached_hole_size = 0; + goto full_search; + } + return -ENOMEM; + } + if (likely(!vma || addr + len <= vma->vm_start)) { + /* + * Remember the place where we stopped the search: + */ + mm->free_area_cache = addr + len; + return addr; + } + if (addr + mm->cached_hole_size < vma->vm_start) + mm->cached_hole_size = vma->vm_start - addr; + + addr = vma->vm_end; + if (do_colour_align) + addr = COLOUR_ALIGN(addr, pgoff); + } +} +#endif /* CONFIG_MMU */ /* * You really shouldn't be using read() or write() on /dev/mem. This -- cgit v1.2.3-59-g8ed1b