ARM: simplify page type handling

There's no need to have anything here on ARM other than the distinction
between writable and non-writable pages (and even that could likely be
eliminated, but with a more intrusive change). Limit type to a single
bit and drop pinned and validated flags altogether.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 341bacf174e066e3c39f20eada628a06b058edcb..45551850392467f9c771631cb72727400cddf9f9 100644 (file)
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -1184,8 +1184,7 @@ void share_xen_page_with_guest(struct page_info *page,
     spin_lock(&d->page_alloc_lock);
 
     /* The incremented type count pins as writable or read-only. */
-    page->u.inuse.type_info  = (readonly ? PGT_none : PGT_writable_page);
-    page->u.inuse.type_info |= PGT_validated | 1;
+    page->u.inuse.type_info = (readonly ? PGT_none : PGT_writable_page) | 1;
 
     page_set_owner(page, d);
     smp_wmb(); /* install valid domain ptr before updating refcnt. */

diff --git a/xen/common/memory.c b/xen/common/memory.c
index 09d329da0fd2bd798a830cfa19fccf7353d65d7f..493cda4f85d80473a3d8cf4b3b955302cbe4f181 100644 (file)
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -354,8 +354,10 @@ int guest_remove_page(struct domain *d, unsigned long gmfn)
 
     rc = guest_physmap_remove_page(d, _gfn(gmfn), mfn, 0);
 
+#ifdef _PGT_pinned
     if ( !rc && test_and_clear_bit(_PGT_pinned, &page->u.inuse.type_info) )
         put_page_and_type(page);
+#endif
 
     /*
      * With the lack of an IOMMU on some platforms, domains with DMA-capable

diff --git a/xen/include/asm-arm/mm.h b/xen/include/asm-arm/mm.h
index 274b1752b31168c398555e859f442532392afc08..13c673a2c3093886210f25ff17eba38c84a871e4 100644 (file)
--- a/xen/include/asm-arm/mm.h
+++ b/xen/include/asm-arm/mm.h
@@ -77,20 +77,12 @@ struct page_info
 #define PG_shift(idx)   (BITS_PER_LONG - (idx))
 #define PG_mask(x, idx) (x ## UL << PG_shift(idx))
 
-#define PGT_none          PG_mask(0, 4)  /* no special uses of this page   */
-#define PGT_writable_page PG_mask(7, 4)  /* has writable mappings?         */
-#define PGT_type_mask     PG_mask(15, 4) /* Bits 28-31 or 60-63.           */
-
- /* Owning guest has pinned this page to its current type? */
-#define _PGT_pinned       PG_shift(5)
-#define PGT_pinned        PG_mask(1, 5)
-
- /* Has this page been validated for use as its current type? */
-#define _PGT_validated    PG_shift(6)
-#define PGT_validated     PG_mask(1, 6)
+#define PGT_none          PG_mask(0, 1)  /* no special uses of this page   */
+#define PGT_writable_page PG_mask(1, 1)  /* has writable mappings?         */
+#define PGT_type_mask     PG_mask(1, 1)  /* Bits 31 or 63.                 */
 
  /* Count of uses of this frame as its current type. */
-#define PGT_count_width   PG_shift(9)
+#define PGT_count_width   PG_shift(2)
 #define PGT_count_mask    ((1UL<<PGT_count_width)-1)
 
  /* Cleared when the owning guest 'frees' this page. */