vm_extern: use standard address checkers everywhere

Define simple functions for alignment and boundary checks and use them
everywhere instead of having slightly different implementations
scattered about. Define them in vm_extern.h and use them where
possible where vm_extern.h is included.

Reviewed by:	kib, markj
Differential Revision:	https://reviews.freebsd.org/D33685

5 files changed, 41 insertions, 22 deletions

diff --git a/sys/vm/vm_extern.h b/sys/vm/vm_extern.h
index ed365bd41689..4e03bba66eeb 100644
--- a/sys/vm/vm_extern.h
+++ b/sys/vm/vm_extern.h
@@ -133,5 +133,32 @@ u_int vm_active_count(void);
 u_int vm_inactive_count(void);
 u_int vm_laundry_count(void);
 u_int vm_wait_count(void);
+
+/*
+ * Is pa a multiple of alignment, which is a power-of-two?
+ */
+static inline bool
+vm_addr_align_ok(vm_paddr_t pa, u_long alignment)
+{
+	return ((pa & (alignment - 1)) == 0);
+}
+
+/*
+ * Do the first and last addresses of a range match in all bits except the ones
+ * in -boundary (a power-of-two)?  For boundary == 0, all addresses match.
+ */
+static inline bool
+vm_addr_bound_ok(vm_paddr_t pa, vm_paddr_t size, vm_paddr_t boundary)
+{
+	return (((pa ^ (pa + size - 1)) & -boundary) == 0);
+}
+
+static inline bool
+vm_addr_ok(vm_paddr_t pa, vm_paddr_t size, u_long alignment,
+    vm_paddr_t boundary)
+{
+	return (vm_addr_align_ok(pa, alignment) &&
+	    vm_addr_bound_ok(pa, size, boundary));
+}
 #endif				/* _KERNEL */
 #endif				/* !_VM_EXTERN_H_ */
diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index 87a290b998b9..1b2b5eb8d5e9 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -2032,10 +2032,8 @@ vm_map_alignspace(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
 		 */
 		if (alignment == 0)
 			pmap_align_superpage(object, offset, addr, length);
-		else if ((*addr & (alignment - 1)) != 0) {
-			*addr &= ~(alignment - 1);
-			*addr += alignment;
-		}
+		else
+			*addr = roundup2(*addr, alignment);
 		aligned_addr = *addr;
 		if (aligned_addr == free_addr) {
 			/*
diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index 07691c15d8ef..3398690a9661 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -2656,12 +2656,11 @@ vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end,
 			if (m + npages > m_end)
 				break;
 			pa = VM_PAGE_TO_PHYS(m);
-			if ((pa & (alignment - 1)) != 0) {
+			if (!vm_addr_align_ok(pa, alignment)) {
 				m_inc = atop(roundup2(pa, alignment) - pa);
 				continue;
 			}
-			if (rounddown2(pa ^ (pa + ptoa(npages) - 1),
-			    boundary) != 0) {
+			if (!vm_addr_bound_ok(pa, ptoa(npages), boundary)) {
 				m_inc = atop(roundup2(pa, boundary) - pa);
 				continue;
 			}
diff --git a/sys/vm/vm_phys.c b/sys/vm/vm_phys.c
index ad997581e77c..9a13fe23c874 100644
--- a/sys/vm/vm_phys.c
+++ b/sys/vm/vm_phys.c
@@ -179,6 +179,7 @@ static void _vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int domain);
 static void vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end);
 static void vm_phys_split_pages(vm_page_t m, int oind, struct vm_freelist *fl,
     int order, int tail);
+
 /*
  * Red-black tree helpers for vm fictitious range management.
  */
@@ -1465,8 +1466,7 @@ vm_phys_alloc_seg_contig(struct vm_phys_seg *seg, u_long npages,
 				pa = VM_PAGE_TO_PHYS(m_ret);
 				pa_end = pa + size;
 				if (pa >= low && pa_end <= high &&
-				    (pa & (alignment - 1)) == 0 &&
-				    rounddown2(pa ^ (pa_end - 1), boundary) == 0)
+				    vm_addr_ok(pa, size, alignment, boundary))
 					goto done;
 			}
 		}
diff --git a/sys/vm/vm_reserv.c b/sys/vm/vm_reserv.c
index b4902942224d..639121806857 100644
--- a/sys/vm/vm_reserv.c
+++ b/sys/vm/vm_reserv.c
@@ -656,10 +656,8 @@ vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex, int domain,
 	 * possible size satisfy the alignment and boundary requirements?
 	 */
 	pa = VM_RESERV_INDEX(object, pindex) << PAGE_SHIFT;
-	if ((pa & (alignment - 1)) != 0)
-		return (NULL);
 	size = npages << PAGE_SHIFT;
-	if (((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0)
+	if (!vm_addr_ok(pa, size, alignment, boundary))
 		return (NULL);
 
 	/*
@@ -682,8 +680,7 @@ vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex, int domain,
 		m = &rv->pages[index];
 		pa = VM_PAGE_TO_PHYS(m);
 		if (pa < low || pa + size > high ||
-		    (pa & (alignment - 1)) != 0 ||
-		    ((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0)
+		    !vm_addr_ok(pa, size, alignment, boundary))
 			goto out;
 		/* Handle vm_page_rename(m, new_object, ...). */
 		for (i = 0; i < npages; i++)
@@ -1333,7 +1330,7 @@ vm_reserv_reclaim_contig(int domain, u_long npages, vm_paddr_t low,
 	 * doesn't include a boundary-multiple within it.  Otherwise,
 	 * no boundary-constrained allocation is possible.
 	 */
-	if (size > boundary && boundary > 0)
+	if (!vm_addr_bound_ok(0, size, boundary))
 		return (NULL);
 	marker = &vm_rvd[domain].marker;
 	queue = &vm_rvd[domain].partpop;
@@ -1360,7 +1357,7 @@ vm_reserv_reclaim_contig(int domain, u_long npages, vm_paddr_t low,
 			/* This entire reservation is too high; go to next. */
 			continue;
 		}
-		if ((pa & (alignment - 1)) != 0) {
+		if (!vm_addr_align_ok(pa, alignment)) {
 			/* This entire reservation is unaligned; go to next. */
 			continue;
 		}
@@ -1397,12 +1394,10 @@ vm_reserv_reclaim_contig(int domain, u_long npages, vm_paddr_t low,
 			vm_reserv_unlock(rv);
 			m_ret = &rv->pages[posn];
 			pa = VM_PAGE_TO_PHYS(m_ret);
-			KASSERT((pa & (alignment - 1)) == 0,
-			    ("%s: adjusted address does not align to %lx",
-			    __func__, alignment));
-			KASSERT(((pa ^ (pa + size - 1)) & -boundary) == 0,
-			    ("%s: adjusted address spans boundary to %jx",
-			    __func__, (uintmax_t)boundary));
+			KASSERT(vm_addr_ok(pa, size, alignment, boundary),
+			    ("%s: adjusted address not aligned/bounded to "
+			     "%lx/%jx",
+			     __func__, alignment, (uintmax_t)boundary));
 			return (m_ret);
 		}
 		vm_reserv_domain_lock(domain);