x86 PAT: change track_pfn_vma_new to take pgprot_t pointer param

Impact: cleanup

Change the protection parameter for track_pfn_vma_new() into a pgprot_t pointer.
Subsequent patch changes the x86 PAT handling to return a compatible
memtype in pgprot_t, if what was requested cannot be allowed due to conflicts.
No fuctionality change in this patch.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 9 insertions, 8 deletions

diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 85cbd3cd3723..f88ac80530c0 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -741,7 +741,7 @@ cleanup_ret:
  * Note that this function can be called with caller trying to map only a
  * subrange/page inside the vma.
  */
-int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t prot,
+int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot,
                         unsigned long pfn, unsigned long size)
 {
         int retval = 0;
@@ -758,14 +758,14 @@ int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t prot,
         if (is_linear_pfn_mapping(vma)) {
                 /* reserve the whole chunk starting from vm_pgoff */
                 paddr = (resource_size_t)vma->vm_pgoff << PAGE_SHIFT;
-                return reserve_pfn_range(paddr, vma_size, prot);
+                return reserve_pfn_range(paddr, vma_size, *prot);
         }
 
         /* reserve page by page using pfn and size */
         base_paddr = (resource_size_t)pfn << PAGE_SHIFT;
         for (i = 0; i < size; i += PAGE_SIZE) {
                 paddr = base_paddr + i;
-                retval = reserve_pfn_range(paddr, PAGE_SIZE, prot);
+                retval = reserve_pfn_range(paddr, PAGE_SIZE, *prot);
                 if (retval)
                         goto cleanup_ret;
         }
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 72ebe91005a8..8e6d0ca70aba 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -301,7 +301,7 @@ static inline void ptep_modify_prot_commit(struct mm_struct *mm,
  * track_pfn_vma_new is called when a _new_ pfn mapping is being established
  * 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_vma_new(struct vm_area_struct *vma, pgprot_t *prot,
                                         unsigned long pfn, unsigned long size)
 {
         return 0;
@@ -332,7 +332,7 @@ static inline void untrack_pfn_vma(struct vm_area_struct *vma,
 {
 }
 #else
-extern int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t prot,
+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,
diff --git a/mm/memory.c b/mm/memory.c
index d3ee2ea5615c..22bfa7a47a0b 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1511,6 +1511,7 @@ int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
                         unsigned long pfn)
 {
         int ret;
+        pgprot_t pgprot = vma->vm_page_prot;
         /*
          * Technically, architectures with pte_special can avoid all these
          * restrictions (same for remap_pfn_range).  However we would like
@@ -1525,10 +1526,10 @@ 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, vma->vm_page_prot, pfn, PAGE_SIZE))
+        if (track_pfn_vma_new(vma, &pgprot, pfn, PAGE_SIZE))
                 return -EINVAL;
 
-        ret = insert_pfn(vma, addr, pfn, vma->vm_page_prot);
+        ret = insert_pfn(vma, addr, pfn, pgprot);
 
         if (ret)
                 untrack_pfn_vma(vma, pfn, PAGE_SIZE);
@@ -1671,7 +1672,7 @@ 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_vma_new(vma, &prot, pfn, PAGE_ALIGN(size));
         if (err) {
                 /*
                  * To indicate that track_pfn related cleanup is not