x86: PAT: hooks in generic vm code to help archs to track pfnmap regions - v3

Impact: Introduces new hooks, which are currently null.

Introduce generic hooks in remap_pfn_range and vm_insert_pfn and
corresponding copy and free routines with reserve and free tracking.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This commit is contained in:
venkatesh.pallipadi@intel.com 2008-12-18 11:41:29 -08:00 committed by H. Peter Anvin
parent e121e41844
commit 2ab640379a
2 changed files with 81 additions and 1 deletions

View File

@ -155,6 +155,12 @@ static inline int is_pfn_mapping(struct vm_area_struct *vma)
return (vma->vm_flags & VM_PFNMAP);
}
extern int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t prot,
unsigned long pfn, unsigned long size);
extern int track_pfn_vma_copy(struct vm_area_struct *vma);
extern void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn,
unsigned long size);
/*
* vm_fault is filled by the the pagefault handler and passed to the vma's
* ->fault function. The vma's ->fault is responsible for returning a bitmask

View File

@ -99,6 +99,50 @@ int randomize_va_space __read_mostly =
2;
#endif
#ifndef track_pfn_vma_new
/*
* Interface that can be used by architecture code to keep track of
* memory type of pfn mappings (remap_pfn_range, vm_insert_pfn)
*
* track_pfn_vma_new is called when a _new_ pfn mapping is being established
* for physical range indicated by pfn and size.
*/
int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t prot,
unsigned long pfn, unsigned long size)
{
return 0;
}
#endif
#ifndef track_pfn_vma_copy
/*
* Interface that can be used by architecture code to keep track of
* memory type of pfn mappings (remap_pfn_range, vm_insert_pfn)
*
* track_pfn_vma_copy is called when vma that is covering the pfnmap gets
* copied through copy_page_range().
*/
int track_pfn_vma_copy(struct vm_area_struct *vma)
{
return 0;
}
#endif
#ifndef untrack_pfn_vma
/*
* Interface that can be used by architecture code to keep track of
* memory type of pfn mappings (remap_pfn_range, vm_insert_pfn)
*
* untrack_pfn_vma is called while unmapping a pfnmap for a region.
* untrack can be called for a specific region indicated by pfn and size or
* can be for the entire vma (in which case size can be zero).
*/
void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn,
unsigned long size)
{
}
#endif
static int __init disable_randmaps(char *s)
{
randomize_va_space = 0;
@ -669,6 +713,16 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
if (is_vm_hugetlb_page(vma))
return copy_hugetlb_page_range(dst_mm, src_mm, vma);
if (is_pfn_mapping(vma)) {
/*
* We do not free on error cases below as remove_vma
* gets called on error from higher level routine
*/
ret = track_pfn_vma_copy(vma);
if (ret)
return ret;
}
/*
* We need to invalidate the secondary MMU mappings only when
* there could be a permission downgrade on the ptes of the
@ -915,6 +969,9 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp,
if (vma->vm_flags & VM_ACCOUNT)
*nr_accounted += (end - start) >> PAGE_SHIFT;
if (is_pfn_mapping(vma))
untrack_pfn_vma(vma, 0, 0);
while (start != end) {
if (!tlb_start_valid) {
tlb_start = start;
@ -1473,6 +1530,7 @@ out:
int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn)
{
int ret;
/*
* Technically, architectures with pte_special can avoid all these
* restrictions (same for remap_pfn_range). However we would like
@ -1487,7 +1545,15 @@ int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
if (addr < vma->vm_start || addr >= vma->vm_end)
return -EFAULT;
return insert_pfn(vma, addr, pfn, vma->vm_page_prot);
if (track_pfn_vma_new(vma, vma->vm_page_prot, pfn, PAGE_SIZE))
return -EINVAL;
ret = insert_pfn(vma, addr, pfn, vma->vm_page_prot);
if (ret)
untrack_pfn_vma(vma, pfn, PAGE_SIZE);
return ret;
}
EXPORT_SYMBOL(vm_insert_pfn);
@ -1625,6 +1691,10 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP;
err = track_pfn_vma_new(vma, prot, pfn, PAGE_ALIGN(size));
if (err)
return -EINVAL;
BUG_ON(addr >= end);
pfn -= addr >> PAGE_SHIFT;
pgd = pgd_offset(mm, addr);
@ -1636,6 +1706,10 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
if (err)
break;
} while (pgd++, addr = next, addr != end);
if (err)
untrack_pfn_vma(vma, pfn, PAGE_ALIGN(size));
return err;
}
EXPORT_SYMBOL(remap_pfn_range);