1 files changed, 117 insertions, 71 deletions

diff --git a/kernel/resource.c b/kernel/resource.c
index fcbca39dbc45..12004452d999 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -48,27 +48,37 @@ struct resource iomem_resource = {
 };
 EXPORT_SYMBOL(iomem_resource);
 
-/* constraints to be met while allocating resources */
-struct resource_constraint {
-	resource_size_t min, max, align;
-	resource_size_t (*alignf)(void *, const struct resource *,
-			resource_size_t, resource_size_t);
-	void *alignf_data;
-};
-
 static DEFINE_RWLOCK(resource_lock);
 
-static struct resource *next_resource(struct resource *p, bool skip_children)
+/*
+ * Return the next node of @p in pre-order tree traversal.  If
+ * @skip_children is true, skip the descendant nodes of @p in
+ * traversal.  If @p is a descendant of @subtree_root, only traverse
+ * the subtree under @subtree_root.
+ */
+static struct resource *next_resource(struct resource *p, bool skip_children,
+				      struct resource *subtree_root)
 {
 	if (!skip_children && p->child)
 		return p->child;
-	while (!p->sibling && p->parent)
+	while (!p->sibling && p->parent) {
 		p = p->parent;
+		if (p == subtree_root)
+			return NULL;
+	}
 	return p->sibling;
 }
 
+/*
+ * Traverse the resource subtree under @_root in pre-order, excluding
+ * @_root itself.
+ *
+ * NOTE: '__p' is introduced to avoid shadowing '_p' outside of loop.
+ * And it is referenced to avoid unused variable warning.
+ */
 #define for_each_resource(_root, _p, _skip_children) \
-	for ((_p) = (_root)->child; (_p); (_p) = next_resource(_p, _skip_children))
+	for (typeof(_root) __root = (_root), __p = _p = __root->child;	\
+	     __p && _p; _p = next_resource(_p, _skip_children, __root))
 
 #ifdef CONFIG_PROC_FS
 
@@ -96,7 +106,7 @@ static void *r_next(struct seq_file *m, void *v, loff_t *pos)
 
 	(*pos)++;
 
-	return (void *)next_resource(p, false);
+	return (void *)next_resource(p, false, NULL);
 }
 
 static void r_stop(struct seq_file *m, void *v)
@@ -305,6 +315,11 @@ int release_resource(struct resource *old)
 
 EXPORT_SYMBOL(release_resource);
 
+static bool is_type_match(struct resource *p, unsigned long flags, unsigned long desc)
+{
+	return (p->flags & flags) == flags && (desc == IORES_DESC_NONE || desc == p->desc);
+}
+
 /**
  * find_next_iomem_res - Finds the lowest iomem resource that covers part of
  *			 [@start..@end].
@@ -347,13 +362,9 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end,
 		if (p->end < start)
 			continue;
 
-		if ((p->flags & flags) != flags)
-			continue;
-		if ((desc != IORES_DESC_NONE) && (desc != p->desc))
-			continue;
-
 		/* Found a match, break */
-		break;
+		if (is_type_match(p, flags, desc))
+			break;
 	}
 
 	if (p) {
@@ -458,8 +469,7 @@ int walk_system_ram_res_rev(u64 start, u64 end, void *arg,
 			/* re-alloc */
 			struct resource *rams_new;
 
-			rams_new = kvrealloc(rams, rams_size * sizeof(struct resource),
-					     (rams_size + 16) * sizeof(struct resource),
+			rams_new = kvrealloc(rams, (rams_size + 16) * sizeof(struct resource),
 					     GFP_KERNEL);
 			if (!rams_new)
 				goto out;
@@ -468,9 +478,7 @@ int walk_system_ram_res_rev(u64 start, u64 end, void *arg,
 			rams_size += 16;
 		}
 
-		rams[i].start = res.start;
-		rams[i++].end = res.end;
-
+		rams[i++] = res;
 		start = res.end + 1;
 	}
 
@@ -548,20 +556,55 @@ static int __region_intersects(struct resource *parent, resource_size_t start,
 			       size_t size, unsigned long flags,
 			       unsigned long desc)
 {
-	struct resource res;
 	int type = 0; int other = 0;
-	struct resource *p;
+	struct resource *p, *dp;
+	struct resource res, o;
+	bool covered;
 
 	res.start = start;
 	res.end = start + size - 1;
 
 	for (p = parent->child; p ; p = p->sibling) {
-		bool is_type = (((p->flags & flags) == flags) &&
-				((desc == IORES_DESC_NONE) ||
-				 (desc == p->desc)));
-
-		if (resource_overlaps(p, &res))
-			is_type ? type++ : other++;
+		if (!resource_intersection(p, &res, &o))
+			continue;
+		if (is_type_match(p, flags, desc)) {
+			type++;
+			continue;
+		}
+		/*
+		 * Continue to search in descendant resources as if the
+		 * matched descendant resources cover some ranges of 'p'.
+		 *
+		 * |------------- "CXL Window 0" ------------|
+		 * |-- "System RAM" --|
+		 *
+		 * will behave similar as the following fake resource
+		 * tree when searching "System RAM".
+		 *
+		 * |-- "System RAM" --||-- "CXL Window 0a" --|
+		 */
+		covered = false;
+		for_each_resource(p, dp, false) {
+			if (!resource_overlaps(dp, &res))
+				continue;
+			if (is_type_match(dp, flags, desc)) {
+				type++;
+				/*
+				 * Range from 'o.start' to 'dp->start'
+				 * isn't covered by matched resource.
+				 */
+				if (dp->start > o.start)
+					break;
+				if (dp->end >= o.end) {
+					covered = true;
+					break;
+				}
+				/* Remove covered range */
+				o.start = max(o.start, dp->end + 1);
+			}
+		}
+		if (!covered)
+			other++;
 	}
 
 	if (type == 0)
@@ -610,14 +653,6 @@ void __weak arch_remove_reservations(struct resource *avail)
 {
 }
 
-static resource_size_t simple_align_resource(void *data,
-					     const struct resource *avail,
-					     resource_size_t size,
-					     resource_size_t align)
-{
-	return avail->start;
-}
-
 static void resource_clip(struct resource *res, resource_size_t min,
 			  resource_size_t max)
 {
@@ -628,16 +663,16 @@ static void resource_clip(struct resource *res, resource_size_t min,
 }
 
 /*
- * Find empty slot in the resource tree with the given range and
+ * Find empty space in the resource tree with the given range and
  * alignment constraints
  */
-static int __find_resource(struct resource *root, struct resource *old,
-			 struct resource *new,
-			 resource_size_t  size,
-			 struct resource_constraint *constraint)
+static int __find_resource_space(struct resource *root, struct resource *old,
+				 struct resource *new, resource_size_t size,
+				 struct resource_constraint *constraint)
 {
 	struct resource *this = root->child;
 	struct resource tmp = *new, avail, alloc;
+	resource_alignf alignf = constraint->alignf;
 
 	tmp.start = root->start;
 	/*
@@ -666,8 +701,12 @@ static int __find_resource(struct resource *root, struct resource *old,
 		avail.flags = new->flags & ~IORESOURCE_UNSET;
 		if (avail.start >= tmp.start) {
 			alloc.flags = avail.flags;
-			alloc.start = constraint->alignf(constraint->alignf_data, &avail,
-					size, constraint->align);
+			if (alignf) {
+				alloc.start = alignf(constraint->alignf_data,
+						     &avail, size, constraint->align);
+			} else {
+				alloc.start = avail.start;
+			}
 			alloc.end = alloc.start + size - 1;
 			if (alloc.start <= alloc.end &&
 			    resource_contains(&avail, &alloc)) {
@@ -687,15 +726,27 @@ next:		if (!this || this->end == root->end)
 	return -EBUSY;
 }
 
-/*
- * Find empty slot in the resource tree given range and alignment.
+/**
+ * find_resource_space - Find empty space in the resource tree
+ * @root:	Root resource descriptor
+ * @new:	Resource descriptor awaiting an empty resource space
+ * @size:	The minimum size of the empty space
+ * @constraint:	The range and alignment constraints to be met
+ *
+ * Finds an empty space under @root in the resource tree satisfying range and
+ * alignment @constraints.
+ *
+ * Return:
+ * * %0		- if successful, @new members start, end, and flags are altered.
+ * * %-EBUSY	- if no empty space was found.
  */
-static int find_resource(struct resource *root, struct resource *new,
+int find_resource_space(struct resource *root, struct resource *new,
 			resource_size_t size,
-			struct resource_constraint  *constraint)
+			struct resource_constraint *constraint)
 {
-	return  __find_resource(root, NULL, new, size, constraint);
+	return  __find_resource_space(root, NULL, new, size, constraint);
 }
+EXPORT_SYMBOL_GPL(find_resource_space);
 
 /**
  * reallocate_resource - allocate a slot in the resource tree given range & alignment.
@@ -705,7 +756,7 @@ static int find_resource(struct resource *root, struct resource *new,
  * @root: root resource descriptor
  * @old:  resource descriptor desired by caller
  * @newsize: new size of the resource descriptor
- * @constraint: the size and alignment constraints to be met.
+ * @constraint: the memory range and alignment constraints to be met.
  */
 static int reallocate_resource(struct resource *root, struct resource *old,
 			       resource_size_t newsize,
@@ -717,7 +768,7 @@ static int reallocate_resource(struct resource *root, struct resource *old,
 
 	write_lock(&resource_lock);
 
-	if ((err = __find_resource(root, old, &new, newsize, constraint)))
+	if ((err = __find_resource_space(root, old, &new, newsize, constraint)))
 		goto out;
 
 	if (resource_contains(&new, old)) {
@@ -761,18 +812,12 @@ out:
 int allocate_resource(struct resource *root, struct resource *new,
 		      resource_size_t size, resource_size_t min,
 		      resource_size_t max, resource_size_t align,
-		      resource_size_t (*alignf)(void *,
-						const struct resource *,
-						resource_size_t,
-						resource_size_t),
+		      resource_alignf alignf,
 		      void *alignf_data)
 {
 	int err;
 	struct resource_constraint constraint;
 
-	if (!alignf)
-		alignf = simple_align_resource;
-
 	constraint.min = min;
 	constraint.max = max;
 	constraint.align = align;
@@ -786,7 +831,7 @@ int allocate_resource(struct resource *root, struct resource *new,
 	}
 
 	write_lock(&resource_lock);
-	err = find_resource(root, new, size, &constraint);
+	err = find_resource_space(root, new, size, &constraint);
 	if (err >= 0 && __request_resource(root, new))
 		err = -EBUSY;
 	write_unlock(&resource_lock);
@@ -953,7 +998,7 @@ void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
  * to use this interface. The former are built-in and only the latter,
  * CXL, is a module.
  */
-EXPORT_SYMBOL_NS_GPL(insert_resource_expand_to_fit, CXL);
+EXPORT_SYMBOL_NS_GPL(insert_resource_expand_to_fit, "CXL");
 
 /**
  * remove_resource - Remove a resource in the resource tree
@@ -1638,8 +1683,7 @@ void __devm_release_region(struct device *dev, struct resource *parent,
 {
 	struct region_devres match_data = { parent, start, n };
 
-	__release_region(parent, start, n);
-	WARN_ON(devres_destroy(dev, devm_region_release, devm_region_match,
+	WARN_ON(devres_release(dev, devm_region_release, devm_region_match,
 			       &match_data));
 }
 EXPORT_SYMBOL(__devm_release_region);
@@ -1824,7 +1868,11 @@ EXPORT_SYMBOL(resource_list_free);
 #ifdef CONFIG_GET_FREE_REGION
 #define GFR_DESCENDING		(1UL << 0)
 #define GFR_REQUEST_REGION	(1UL << 1)
-#define GFR_DEFAULT_ALIGN (1UL << PA_SECTION_SHIFT)
+#ifdef PA_SECTION_SHIFT
+#define GFR_DEFAULT_ALIGN	(1UL << PA_SECTION_SHIFT)
+#else
+#define GFR_DEFAULT_ALIGN	PAGE_SIZE
+#endif
 
 static resource_size_t gfr_start(struct resource *base, resource_size_t size,
 				 resource_size_t align, unsigned long flags)
@@ -1832,12 +1880,11 @@ static resource_size_t gfr_start(struct resource *base, resource_size_t size,
 	if (flags & GFR_DESCENDING) {
 		resource_size_t end;
 
-		end = min_t(resource_size_t, base->end,
-			    (1ULL << MAX_PHYSMEM_BITS) - 1);
+		end = min_t(resource_size_t, base->end, DIRECT_MAP_PHYSMEM_END);
 		return end - size + 1;
 	}
 
-	return ALIGN(base->start, align);
+	return ALIGN(max(base->start, align), align);
 }
 
 static bool gfr_continue(struct resource *base, resource_size_t addr,
@@ -1850,8 +1897,7 @@ static bool gfr_continue(struct resource *base, resource_size_t addr,
 	 * @size did not wrap 0.
 	 */
 	return addr > addr - size &&
-	       addr <= min_t(resource_size_t, base->end,
-			     (1ULL << MAX_PHYSMEM_BITS) - 1);
+	       addr <= min_t(resource_size_t, base->end, DIRECT_MAP_PHYSMEM_END);
 }
 
 static resource_size_t gfr_next(resource_size_t addr, resource_size_t size,
@@ -2012,7 +2058,7 @@ struct resource *alloc_free_mem_region(struct resource *base,
 	return get_free_mem_region(NULL, base, size, align, name,
 				   IORES_DESC_NONE, flags);
 }
-EXPORT_SYMBOL_NS_GPL(alloc_free_mem_region, CXL);
+EXPORT_SYMBOL_GPL(alloc_free_mem_region);
 #endif /* CONFIG_GET_FREE_REGION */
 
 static int __init strict_iomem(char *str)