Provide typedefs for the type of bit mask for the page bits.

Use the defined types instead of int when manipulating masks.
Supposedly, it could fix support for 32KB page size in the
machine-independend VM layer.

Reviewed by:	alc
MFC after:	2 weeks

3 files changed, 33 insertions, 30 deletions

diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index f14da4a..389aea5 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -137,7 +137,7 @@ SYSCTL_INT(_vm, OID_AUTO, tryrelock_restart, CTLFLAG_RD,
 
 static uma_zone_t fakepg_zone;
 
-static void vm_page_clear_dirty_mask(vm_page_t m, int pagebits);
+static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits);
 static void vm_page_queue_remove(int queue, vm_page_t m);
 static void vm_page_enqueue(int queue, vm_page_t m);
 static void vm_page_init_fakepg(void *dummy);
@@ -2350,7 +2350,7 @@ retrylookup:
  *
  * Inputs are required to range within a page.
  */
-int
+vm_page_bits_t
 vm_page_bits(int base, int size)
 {
 	int first_bit;
@@ -2367,7 +2367,8 @@ vm_page_bits(int base, int size)
 	first_bit = base >> DEV_BSHIFT;
 	last_bit = (base + size - 1) >> DEV_BSHIFT;
 
-	return ((2 << last_bit) - (1 << first_bit));
+	return (((vm_page_bits_t)2 << last_bit) -
+	    ((vm_page_bits_t)1 << first_bit));
 }
 
 /*
@@ -2426,7 +2427,7 @@ vm_page_set_valid(vm_page_t m, int base, int size)
  * Clear the given bits from the specified page's dirty field.
  */
 static __inline void
-vm_page_clear_dirty_mask(vm_page_t m, int pagebits)
+vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits)
 {
 	uintptr_t addr;
 #if PAGE_SIZE < 16384
@@ -2455,7 +2456,6 @@ vm_page_clear_dirty_mask(vm_page_t m, int pagebits)
 		 */
 		addr = (uintptr_t)&m->dirty;
 #if PAGE_SIZE == 32768
-#error pagebits too short
 		atomic_clear_64((uint64_t *)addr, pagebits);
 #elif PAGE_SIZE == 16384
 		atomic_clear_32((uint32_t *)addr, pagebits);
@@ -2492,8 +2492,8 @@ vm_page_clear_dirty_mask(vm_page_t m, int pagebits)
 void
 vm_page_set_validclean(vm_page_t m, int base, int size)
 {
-	u_long oldvalid;
-	int endoff, frag, pagebits;
+	vm_page_bits_t oldvalid, pagebits;
+	int endoff, frag;
 
 	VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
 	if (size == 0)	/* handle degenerate case */
@@ -2505,7 +2505,7 @@ vm_page_set_validclean(vm_page_t m, int base, int size)
 	 * first block.
 	 */
 	if ((frag = base & ~(DEV_BSIZE - 1)) != base &&
-	    (m->valid & (1 << (base >> DEV_BSHIFT))) == 0)
+	    (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0)
 		pmap_zero_page_area(m, frag, base - frag);
 
 	/*
@@ -2515,7 +2515,7 @@ vm_page_set_validclean(vm_page_t m, int base, int size)
 	 */
 	endoff = base + size;
 	if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff &&
-	    (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0)
+	    (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0)
 		pmap_zero_page_area(m, endoff,
 		    DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
 
@@ -2585,7 +2585,7 @@ vm_page_clear_dirty(vm_page_t m, int base, int size)
 void
 vm_page_set_invalid(vm_page_t m, int base, int size)
 {
-	int bits;
+	vm_page_bits_t bits;
 
 	VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
 	KASSERT((m->oflags & VPO_BUSY) == 0,
@@ -2625,8 +2625,7 @@ vm_page_zero_invalid(vm_page_t m, boolean_t setvalid)
 	 */
 	for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) {
 		if (i == (PAGE_SIZE / DEV_BSIZE) || 
-		    (m->valid & (1 << i))
-		) {
+		    (m->valid & ((vm_page_bits_t)1 << i))) {
 			if (i > b) {
 				pmap_zero_page_area(m, 
 				    b << DEV_BSHIFT, (i - b) << DEV_BSHIFT);
@@ -2656,9 +2655,10 @@ vm_page_zero_invalid(vm_page_t m, boolean_t setvalid)
 int
 vm_page_is_valid(vm_page_t m, int base, int size)
 {
-	int bits = vm_page_bits(base, size);
+	vm_page_bits_t bits;
 
 	VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
+	bits = vm_page_bits(base, size);
 	if (m->valid && ((m->valid & bits) == bits))
 		return 1;
 	else
diff --git a/sys/vm/vm_page.h b/sys/vm/vm_page.h
index 23637bb..e3eb08c 100644
--- a/sys/vm/vm_page.h
+++ b/sys/vm/vm_page.h
@@ -113,6 +113,20 @@
 
 TAILQ_HEAD(pglist, vm_page);
 
+#if PAGE_SIZE == 4096
+#define VM_PAGE_BITS_ALL 0xffu
+typedef uint8_t vm_page_bits_t;
+#elif PAGE_SIZE == 8192
+#define VM_PAGE_BITS_ALL 0xffffu
+typedef uint16_t vm_page_bits_t;
+#elif PAGE_SIZE == 16384
+#define VM_PAGE_BITS_ALL 0xffffffffu
+typedef uint32_t vm_page_bits_t;
+#elif PAGE_SIZE == 32768
+#define VM_PAGE_BITS_ALL 0xfffffffffffffffflu
+typedef uint64_t vm_page_bits_t;
+#endif
+
 struct vm_page {
 	TAILQ_ENTRY(vm_page) pageq;	/* queue info for FIFO queue or free list (Q) */
 	TAILQ_ENTRY(vm_page) listq;	/* pages in same object (O) 	*/
@@ -137,20 +151,8 @@ struct vm_page {
 	u_char	busy;			/* page busy count (O) */
 	/* NOTE that these must support one bit per DEV_BSIZE in a page!!! */
 	/* so, on normal X86 kernels, they must be at least 8 bits wide */
-	/* In reality, support for 32KB pages is not fully implemented. */
-#if PAGE_SIZE == 4096
-	uint8_t	valid;			/* map of valid DEV_BSIZE chunks (O) */
-	uint8_t	dirty;			/* map of dirty DEV_BSIZE chunks (M) */
-#elif PAGE_SIZE == 8192
-	uint16_t valid;			/* map of valid DEV_BSIZE chunks (O) */
-	uint16_t dirty;			/* map of dirty DEV_BSIZE chunks (M) */
-#elif PAGE_SIZE == 16384
-	uint32_t valid;			/* map of valid DEV_BSIZE chunks (O) */
-	uint32_t dirty;			/* map of dirty DEV_BSIZE chunks (M) */
-#elif PAGE_SIZE == 32768
-	uint64_t valid;			/* map of valid DEV_BSIZE chunks (O) */
-	uint64_t dirty;			/* map of dirty DEV_BSIZE chunks (M) */
-#endif
+	vm_page_bits_t valid;		/* map of valid DEV_BSIZE chunks (O) */
+	vm_page_bits_t dirty;		/* map of dirty DEV_BSIZE chunks (M) */
 };
 
 /*
@@ -403,7 +405,7 @@ void vm_page_clear_dirty (vm_page_t, int, int);
 void vm_page_set_invalid (vm_page_t, int, int);
 int vm_page_is_valid (vm_page_t, int, int);
 void vm_page_test_dirty (vm_page_t);
-int vm_page_bits (int, int);
+vm_page_bits_t vm_page_bits(int base, int size);
 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid);
 void vm_page_free_toq(vm_page_t m);
 void vm_page_zero_idle_wakeup(void);
diff --git a/sys/vm/vnode_pager.c b/sys/vm/vnode_pager.c
index e3222cb..cd2658d 100644
--- a/sys/vm/vnode_pager.c
+++ b/sys/vm/vnode_pager.c
@@ -486,15 +486,16 @@ vnode_pager_input_smlfs(object, m)
 	vm_object_t object;
 	vm_page_t m;
 {
-	int bits, i;
 	struct vnode *vp;
 	struct bufobj *bo;
 	struct buf *bp;
 	struct sf_buf *sf;
 	daddr_t fileaddr;
 	vm_offset_t bsize;
-	int error = 0;
+	vm_page_bits_t bits;
+	int error, i;
 
+	error = 0;
 	vp = object->handle;
 	if (vp->v_iflag & VI_DOOMED)
 		return VM_PAGER_BAD;