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authorSuresh Siddha <suresh.b.siddha@intel.com>2012-10-09 03:28:29 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-09 11:22:16 +0400
commit5180da410db6369d1f95c9014da1c9bc33fb043e (patch)
tree1d92975710b33a90f77f39d0ad33669329dea949 /arch/x86
parentb1a86e15dc0304366f50ba1720834bc419c801b1 (diff)
downloadlinux-5180da410db6369d1f95c9014da1c9bc33fb043e.tar.xz
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: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Konstantin 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: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/mm/pat.c47
1 files changed, 36 insertions, 11 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index de36c886cd38..74a702674e86 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -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;
@@ -694,15 +694,12 @@ 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,
- unsigned long pfn, unsigned long size)
+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;
unsigned long flags;
@@ -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);
@@ -723,12 +748,12 @@ 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,
- unsigned long size)
+void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
+ unsigned long size)
{
resource_size_t paddr;
unsigned long prot;