diff options
Diffstat (limited to 'drivers/char/mem.c')
| -rw-r--r-- | drivers/char/mem.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 42187381506b..f182752fe918 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -35,10 +35,6 @@ # include <linux/efi.h> #endif -#if defined(CONFIG_S390_TAPE) && defined(CONFIG_S390_TAPE_CHAR) -extern void tapechar_init(void); -#endif - /* * Architectures vary in how they handle caching for addresses * outside of main memory. @@ -261,7 +257,11 @@ static int mmap_mem(struct file * file, struct vm_area_struct * vma) static int mmap_kmem(struct file * file, struct vm_area_struct * vma) { - unsigned long long val; + unsigned long pfn; + + /* Turn a kernel-virtual address into a physical page frame */ + pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT; + /* * RED-PEN: on some architectures there is more mapped memory * than available in mem_map which pfn_valid checks @@ -269,10 +269,10 @@ static int mmap_kmem(struct file * file, struct vm_area_struct * vma) * * RED-PEN: vmalloc is not supported right now. */ - if (!pfn_valid(vma->vm_pgoff)) + if (!pfn_valid(pfn)) return -EIO; - val = (u64)vma->vm_pgoff << PAGE_SHIFT; - vma->vm_pgoff = __pa(val) >> PAGE_SHIFT; + + vma->vm_pgoff = pfn; return mmap_mem(file, vma); } |