diff options
Diffstat (limited to 'drivers/char/mem.c')
| -rw-r--r-- | drivers/char/mem.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 48839958b0b1..34b815901b20 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -512,11 +512,18 @@ static int mmap_zero(struct file *file, struct vm_area_struct *vma) return 0; } +#ifndef CONFIG_MMU +static unsigned long get_unmapped_area_zero(struct file *file, + unsigned long addr, unsigned long len, + unsigned long pgoff, unsigned long flags) +{ + return -ENOSYS; +} +#else static unsigned long get_unmapped_area_zero(struct file *file, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags) { -#ifdef CONFIG_MMU if (flags & MAP_SHARED) { /* * mmap_zero() will call shmem_zero_setup() to create a file, @@ -527,12 +534,18 @@ static unsigned long get_unmapped_area_zero(struct file *file, return shmem_get_unmapped_area(NULL, addr, len, pgoff, flags); } - /* Otherwise flags & MAP_PRIVATE: with no shmem object beneath it */ - return mm_get_unmapped_area(current->mm, file, addr, len, pgoff, flags); + /* + * Otherwise flags & MAP_PRIVATE: with no shmem object beneath it, + * attempt to map aligned to huge page size if possible, otherwise we + * fall back to system page size mappings. + */ +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + return thp_get_unmapped_area(file, addr, len, pgoff, flags); #else - return -ENOSYS; + return mm_get_unmapped_area(current->mm, file, addr, len, pgoff, flags); #endif } +#endif /* CONFIG_MMU */ static ssize_t write_full(struct file *file, const char __user *buf, size_t count, loff_t *ppos) |