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Commit 5180da41 authored by Suresh Siddha's avatar Suresh Siddha Committed by Linus Torvalds
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x86, pat: separate the pfn attribute tracking for remap_pfn_range and vm_insert_pfn 



With PAT enabled, vm_insert_pfn() looks up the existing pfn memory
attribute and uses it.  Expectation is that the driver reserves the
memory attributes for the pfn before calling vm_insert_pfn().

remap_pfn_range() (when called for the whole vma) will setup a new
attribute (based on the prot argument) for the specified pfn range.
This addresses the legacy usage which typically calls remap_pfn_range()
with a desired memory attribute.  For ranges smaller than the vma size
(which is typically not the case), remap_pfn_range() will use the
existing memory attribute for the pfn range.

Expose two different API's for these different behaviors.
track_pfn_insert() for tracking the pfn attribute set by vm_insert_pfn()
and track_pfn_remap() for the remap_pfn_range().

This cleanup also prepares the ground for the track/untrack pfn vma
routines to take over the ownership of setting PAT specific vm_flag in
the 'vma'.

[khlebnikov@openvz.org: Clear checks in track_pfn_remap()]
[akpm@linux-foundation.org: tweak a few comments]
Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: default avatarKonstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Venkatesh Pallipadi <venki@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b1a86e15

arch/x86/mm/pat.c

+36 −11
Original line number Diff line number Diff line
@@ -664,13 +664,13 @@ static void free_pfn_range(u64 paddr, unsigned long size) 
}



/*

 * track_pfn_vma_copy is called when vma that is covering the pfnmap gets

 * track_pfn_copy is called when vma that is covering the pfnmap gets

 * copied through copy_page_range().

 *

 * If the vma has a linear pfn mapping for the entire range, we get the prot

 * from pte and reserve the entire vma range with single reserve_pfn_range call.

 */

int track_pfn_vma_copy(struct vm_area_struct *vma)

int track_pfn_copy(struct vm_area_struct *vma)

{

	resource_size_t paddr;

	unsigned long prot;
@@ -694,14 +694,11 @@ int track_pfn_vma_copy(struct vm_area_struct *vma) 
}



/*

 * track_pfn_vma_new is called when a _new_ pfn mapping is being established

 * for physical range indicated by pfn and size.

 *

 * prot is passed in as a parameter for the new mapping. If the vma has a

 * linear pfn mapping for the entire range reserve the entire vma range with

 * single reserve_pfn_range call.

 */

int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot,

int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,

		    unsigned long pfn, unsigned long size)

{

	resource_size_t paddr = (resource_size_t)pfn << PAGE_SHIFT;
@@ -714,8 +711,36 @@ int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot, 
	if (!pat_enabled)

		return 0;



	/* for vm_insert_pfn and friends, we set prot based on lookup */

	/*

	 * For anything smaller than the vma size we set prot based on the

	 * lookup.

	 */

	flags = lookup_memtype(paddr);



	/* Check memtype for the remaining pages */

	while (size > PAGE_SIZE) {

		size -= PAGE_SIZE;

		paddr += PAGE_SIZE;

		if (flags != lookup_memtype(paddr))

			return -EINVAL;

	}



	*prot = __pgprot((pgprot_val(vma->vm_page_prot) & (~_PAGE_CACHE_MASK)) |

			 flags);



	return 0;

}



int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,

		     unsigned long pfn)

{

	unsigned long flags;



	if (!pat_enabled)

		return 0;



	/* Set prot based on lookup */

	flags = lookup_memtype((resource_size_t)pfn << PAGE_SHIFT);

	*prot = __pgprot((pgprot_val(vma->vm_page_prot) & (~_PAGE_CACHE_MASK)) |

			 flags);
@@ -723,11 +748,11 @@ int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot, 
}



/*

 * untrack_pfn_vma is called while unmapping a pfnmap for a region.

 * untrack_pfn 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 pfn, size are zero).

 */

void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn,

void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,

		 unsigned long size)

{

	resource_size_t paddr;

include/asm-generic/pgtable.h

+32 −23
Original line number Diff line number Diff line
@@ -381,47 +381,56 @@ static inline void ptep_modify_prot_commit(struct mm_struct *mm, 


#ifndef __HAVE_PFNMAP_TRACKING

/*

 * 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.

 * Interfaces that can be used by architecture code to keep track of

 * memory type of pfn mappings specified by the remap_pfn_range,

 * vm_insert_pfn.

 */



/*

 * track_pfn_remap is called when a _new_ pfn mapping is being established

 * by remap_pfn_range() for physical range indicated by pfn and size.

 */

static inline int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot,

static inline int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,

				  unsigned long pfn, unsigned long size)

{

	return 0;

}



/*

 * 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

 * track_pfn_insert is called when a _new_ single pfn is established

 * by vm_insert_pfn().

 */

static inline int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,

				   unsigned long pfn)

{

	return 0;

}



/*

 * track_pfn_copy is called when vma that is covering the pfnmap gets

 * copied through copy_page_range().

 */

static inline int track_pfn_vma_copy(struct vm_area_struct *vma)

static inline int track_pfn_copy(struct vm_area_struct *vma)

{

	return 0;

}



/*

 * 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).

 * can be for the entire vma (in which case pfn, size are zero).

 */

static inline void untrack_pfn_vma(struct vm_area_struct *vma,

static inline void untrack_pfn(struct vm_area_struct *vma,

			       unsigned long pfn, unsigned long size)

{

}

#else

extern int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot,

extern int track_pfn_remap(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,

extern int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,

			    unsigned long pfn);

extern int track_pfn_copy(struct vm_area_struct *vma);

extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,

			unsigned long size);

#endif

mm/memory.c

+5 −8
Original line number Diff line number Diff line
@@ -1060,7 +1060,7 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, 
		 * 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);

		ret = track_pfn_copy(vma);

		if (ret)

			return ret;

	}
@@ -1328,7 +1328,7 @@ static void unmap_single_vma(struct mmu_gather *tlb, 
		uprobe_munmap(vma, start, end);



	if (unlikely(is_pfn_mapping(vma)))

		untrack_pfn_vma(vma, 0, 0);

		untrack_pfn(vma, 0, 0);



	if (start != end) {

		if (unlikely(is_vm_hugetlb_page(vma))) {
@@ -2162,14 +2162,11 @@ int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr, 


	if (addr < vma->vm_start || addr >= vma->vm_end)

		return -EFAULT;

	if (track_pfn_vma_new(vma, &pgprot, pfn, PAGE_SIZE))

	if (track_pfn_insert(vma, &pgprot, pfn))

		return -EINVAL;



	ret = insert_pfn(vma, addr, pfn, pgprot);



	if (ret)

		untrack_pfn_vma(vma, pfn, PAGE_SIZE);



	return ret;

}

EXPORT_SYMBOL(vm_insert_pfn);
@@ -2311,7 +2308,7 @@ 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));

	err = track_pfn_remap(vma, &prot, pfn, PAGE_ALIGN(size));

	if (err) {

		/*

		 * To indicate that track_pfn related cleanup is not
@@ -2335,7 +2332,7 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, 
	} while (pgd++, addr = next, addr != end);



	if (err)

		untrack_pfn_vma(vma, pfn, PAGE_ALIGN(size));

		untrack_pfn(vma, pfn, PAGE_ALIGN(size));



	return err;

}