powerpc/mm: Add new "set" flag argument to pte/pmd update function

pte_update() is a powerpc-ism used to change the bits of a PTE
when the access permission is being restricted (a flush is
potentially needed).

It uses atomic operations on when needed and handles the hash
synchronization on hash based processors.

It is currently only used to clear PTE bits and so the current
implementation doesn't provide a way to also set PTE bits.

The new _PAGE_NUMA bit, when set, is actually restricting access
so it must use that function too, so this change adds the ability
for pte_update() to also set bits.

We will use this later to set the _PAGE_NUMA bit.

Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 7 insertions, 5 deletions

diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index 65b7b65e8708..62bf5e8e78da 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -510,7 +510,8 @@ int pmdp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
 }
 
 unsigned long pmd_hugepage_update(struct mm_struct *mm, unsigned long addr,
-                                  pmd_t *pmdp, unsigned long clr)
+                                  pmd_t *pmdp, unsigned long clr,
+                                  unsigned long set)
 {
 
         unsigned long old, tmp;
@@ -526,14 +527,15 @@ unsigned long pmd_hugepage_update(struct mm_struct *mm, unsigned long addr,
                 andi.   %1,%0,%6\n\
                 bne-    1b \n\
                 andc    %1,%0,%4 \n\
+                or      %1,%1,%7\n\
                 stdcx.  %1,0,%3 \n\
                 bne-    1b"
         : "=&r" (old), "=&r" (tmp), "=m" (*pmdp)
-        : "r" (pmdp), "r" (clr), "m" (*pmdp), "i" (_PAGE_BUSY)
+        : "r" (pmdp), "r" (clr), "m" (*pmdp), "i" (_PAGE_BUSY), "r" (set)
         : "cc" );
 #else
         old = pmd_val(*pmdp);
-        *pmdp = __pmd(old & ~clr);
+        *pmdp = __pmd((old & ~clr) | set);
 #endif
         if (old & _PAGE_HASHPTE)
                 hpte_do_hugepage_flush(mm, addr, pmdp);
@@ -708,7 +710,7 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
                      pmd_t *pmdp)
 {
-        pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT);
+        pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, 0);
 }
 
 /*
@@ -835,7 +837,7 @@ pmd_t pmdp_get_and_clear(struct mm_struct *mm,
         unsigned long old;
         pgtable_t *pgtable_slot;
 
-        old = pmd_hugepage_update(mm, addr, pmdp, ~0UL);
+        old = pmd_hugepage_update(mm, addr, pmdp, ~0UL, 0);
         old_pmd = __pmd(old);
         /*
          * We have pmd == none and we are holding page_table_lock.