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Diffstat (limited to 'drivers/char/mem.c')
-rw-r--r--drivers/char/mem.c23
1 files changed, 11 insertions, 12 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 42187381506b..91dd669273e0 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.
@@ -235,9 +231,7 @@ static ssize_t write_mem(struct file * file, const char __user * buf,
static int mmap_mem(struct file * file, struct vm_area_struct * vma)
{
#if defined(__HAVE_PHYS_MEM_ACCESS_PROT)
- unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
-
- vma->vm_page_prot = phys_mem_access_prot(file, offset,
+ vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
vma->vm_end - vma->vm_start,
vma->vm_page_prot);
#elif defined(pgprot_noncached)
@@ -261,7 +255,11 @@ 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 +267,10 @@ 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);
}
@@ -920,7 +918,8 @@ static int __init chr_dev_init(void)
mem_class = class_create(THIS_MODULE, "mem");
for (i = 0; i < ARRAY_SIZE(devlist); i++) {
- class_device_create(mem_class, MKDEV(MEM_MAJOR, devlist[i].minor),
+ class_device_create(mem_class, NULL,
+ MKDEV(MEM_MAJOR, devlist[i].minor),
NULL, devlist[i].name);
devfs_mk_cdev(MKDEV(MEM_MAJOR, devlist[i].minor),
S_IFCHR | devlist[i].mode, devlist[i].name);