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Remove (at least temporarily) the "incomplete PFN mapping" support 

With the previous commit, we can handle arbitrary shared re-mappings
even without this complexity, and since the only known private mappings
are for strange users of /dev/mem (which never create an incomplete one),
there seems to be no reason to support it.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Linus Torvalds 2005-12-11 19:57:52 -08:00
parent fb155c1619
commit 7fc7e2eeec
2 changed files with 1 additions and 46 deletions
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1
include/linux/mm.h
View File

@ -163,7 +163,6 @@ extern unsigned int kobjsize(const void *objp);
#define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */
#define VM_NONLINEAR 0x00800000 /* Is non-linear (remap_file_pages) */
#define VM_MAPPED_COPY 0x01000000 /* T if mapped copy of data (nommu mmap) */
#define VM_INCOMPLETE 0x02000000 /* Strange partial PFN mapping marker */
#ifndef VM_STACK_DEFAULT_FLAGS /* arch can override this */
#define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS

46
mm/memory.c
View File

@ -1227,50 +1227,6 @@ int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, struct page *
}
EXPORT_SYMBOL(vm_insert_page);
/*
* Somebody does a pfn remapping that doesn't actually work as a vma.
*
* Do it as individual pages instead, and warn about it. It's bad form,
* and very inefficient.
*/
static int incomplete_pfn_remap(struct vm_area_struct *vma,
unsigned long start, unsigned long end,
unsigned long pfn, pgprot_t prot)
{
static int warn = 10;
struct page *page;
int retval;
if (!(vma->vm_flags & VM_INCOMPLETE)) {
if (warn) {
warn--;
printk("%s does an incomplete pfn remapping", current->comm);
dump_stack();
}
}
vma->vm_flags |= VM_INCOMPLETE | VM_IO | VM_RESERVED;
if (start < vma->vm_start || end > vma->vm_end)
return -EINVAL;
if (!pfn_valid(pfn))
return -EINVAL;
page = pfn_to_page(pfn);
if (!PageReserved(page))
return -EINVAL;
retval = 0;
while (start < end) {
retval = insert_page(vma->vm_mm, start, page, prot);
if (retval < 0)
break;
start += PAGE_SIZE;
page++;
}
return retval;
}
/*
* maps a range of physical memory into the requested pages. the old
* mappings are removed. any references to nonexistent pages results
@ -1365,7 +1321,7 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
*/
if (!(vma->vm_flags & VM_SHARED)) {
if (addr != vma->vm_start || end != vma->vm_end)
return incomplete_pfn_remap(vma, addr, end, pfn, prot);
return -EINVAL;
vma->vm_pgoff = pfn;
}