 @@ -1,1125 +1,1130 @@
-/*	$NetBSD: drm_mm.c,v 1.14 2021/12/19 11:51:32 riastradh Exp $	*/
+/*	$NetBSD: drm_mm.c,v 1.15 2022/02/14 13:02:31 riastradh Exp $	*/
 /**************************************************************************
+ *
  * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND., USA.
  * Copyright 2016 Intel Corporation
  * All Rights Reserved.
+ *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the
  * "Software"), to deal in the Software without restriction, including
  * without limitation the rights to use, copy, modify, merge, publish,
  * distribute, sub license, and/or sell copies of the Software, and to
  * permit persons to whom the Software is furnished to do so, subject to
  * the following conditions:
+ *
  * The above copyright notice and this permission notice (including the
  * next paragraph) shall be included in all copies or substantial portions
  * of the Software.
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ *
  **************************************************************************/
 /*
  * Generic simple memory manager implementation. Intended to be used as a base
  * class implementation for more advanced memory managers.
+ *
  * Note that the algorithm used is quite simple and there might be substantial
  * performance gains if a smarter free list is implemented. Currently it is
  * just an unordered stack of free regions. This could easily be improved if
  * an RB-tree is used instead. At least if we expect heavy fragmentation.
+ *
  * Aligned allocations can also see improvement.
+ *
  * Authors:
  * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: drm_mm.c,v 1.14 2021/12/19 11:51:32 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: drm_mm.c,v 1.15 2022/02/14 13:02:31 riastradh Exp $");
 #include <linux/export.h>
 #include <linux/interval_tree_generic.h>
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/stacktrace.h>
 #include <drm/drm_mm.h>
 /**
  * DOC: Overview
+ *
  * drm_mm provides a simple range allocator. The drivers are free to use the
  * resource allocator from the linux core if it suits them, the upside of drm_mm
  * is that it's in the DRM core. Which means that it's easier to extend for
  * some of the crazier special purpose needs of gpus.
+ *
  * The main data struct is &drm_mm, allocations are tracked in &drm_mm_node.
  * Drivers are free to embed either of them into their own suitable
  * datastructures. drm_mm itself will not do any memory allocations of its own,
  * so if drivers choose not to embed nodes they need to still allocate them
  * themselves.
+ *
  * The range allocator also supports reservation of preallocated blocks. This is
  * useful for taking over initial mode setting configurations from the firmware,
  * where an object needs to be created which exactly matches the firmware's
  * scanout target. As long as the range is still free it can be inserted anytime
  * after the allocator is initialized, which helps with avoiding looped
  * dependencies in the driver load sequence.
+ *
  * drm_mm maintains a stack of most recently freed holes, which of all
  * simplistic datastructures seems to be a fairly decent approach to clustering
  * allocations and avoiding too much fragmentation. This means free space
  * searches are O(num_holes). Given that all the fancy features drm_mm supports
  * something better would be fairly complex and since gfx thrashing is a fairly
  * steep cliff not a real concern. Removing a node again is O(1).
+ *
  * drm_mm supports a few features: Alignment and range restrictions can be
  * supplied. Furthermore every &drm_mm_node has a color value (which is just an
  * opaque unsigned long) which in conjunction with a driver callback can be used
  * to implement sophisticated placement restrictions. The i915 DRM driver uses
  * this to implement guard pages between incompatible caching domains in the
  * graphics TT.
+ *
  * Two behaviors are supported for searching and allocating: bottom-up and
  * top-down. The default is bottom-up. Top-down allocation can be used if the
  * memory area has different restrictions, or just to reduce fragmentation.
+ *
  * Finally iteration helpers to walk all nodes and all holes are provided as are
  * some basic allocator dumpers for debugging.
+ *
  * Note that this range allocator is not thread-safe, drivers need to protect
  * modifications with their own locking. The idea behind this is that for a full
  * memory manager additional data needs to be protected anyway, hence internal
  * locking would be fully redundant.
  */
 #ifdef CONFIG_DRM_DEBUG_MM
 #include <linux/stackdepot.h>
 #define STACKDEPTH 32
 #define BUFSZ 4096
 static noinline void save_stack(struct drm_mm_node *node)
+{
 	unsigned long entries[STACKDEPTH];
 	unsigned int n;
 	n = stack_trace_save(entries, ARRAY_SIZE(entries), 1);
 	/* May be called under spinlock, so avoid sleeping */
 	node->stack = stack_depot_save(entries, n, GFP_NOWAIT);
+}
 static void show_leaks(struct drm_mm *mm)
+{
 	struct drm_mm_node *node;
 	unsigned long *entries;
 	unsigned int nr_entries;
 	char *buf;
 	buf = kmalloc(BUFSZ, GFP_KERNEL);
 	if (!buf)
 		return;
 	list_for_each_entry(node, drm_mm_nodes(mm), node_list) {
 		if (!node->stack) {
 			DRM_ERROR("node [%08"PRIx64" + %08"PRIx64"]: unknown owner\n",
 				  node->start, node->size);
 			continue;
+		}
 		nr_entries = stack_depot_fetch(node->stack, &entries);
 		stack_trace_snprint(buf, BUFSZ, entries, nr_entries, 0);
 		DRM_ERROR("node [%08"PRIx64" + %08"PRIx64"]: inserted at\n%s",
 			  node->start, node->size, buf);
+	}
 	kfree(buf);
+}
 #undef STACKDEPTH
 #undef BUFSZ
 #else
 static void save_stack(struct drm_mm_node *node) { }
 static void show_leaks(struct drm_mm *mm) { }
 #endif
 #define START(node) ((node)->start)
 #define LAST(node)  ((node)->start + (node)->size - 1)
 #ifndef __NetBSD__
 INTERVAL_TREE_DEFINE(struct drm_mm_node, rb,
 		     u64, __subtree_last,
 		     START, LAST, static inline, drm_mm_interval_tree)
 #endif
 struct drm_mm_node *
 __drm_mm_interval_first(const struct drm_mm *mm_const, u64 start, u64 last)
+{
 	struct drm_mm *mm = __UNCONST(mm_const);
 #ifdef __NetBSD__
 	struct drm_mm_node *node;
 	list_for_each_entry(node, &mm->head_node.node_list, node_list) {
 		if (node->start <= start)
 			return node;
+	}
 	return NULL;
 #else
 	return drm_mm_interval_tree_iter_first((struct rb_root_cached *)&mm->interval_tree,
 					       start, last) ?: (struct drm_mm_node *)&mm->head_node;
 #endif
+}
 EXPORT_SYMBOL(__drm_mm_interval_first);
 #ifndef __NetBSD__
 static void drm_mm_interval_tree_add_node(struct drm_mm_node *hole_node,
 					  struct drm_mm_node *node)
+{
 	struct drm_mm *mm = hole_node->mm;
 	struct rb_node **link, *rb;
 	struct drm_mm_node *parent;
 	bool leftmost;
 	node->__subtree_last = LAST(node);
 	if (drm_mm_node_allocated(hole_node)) {
 		rb = &hole_node->rb;
 		while (rb) {
 			parent = rb_entry(rb, struct drm_mm_node, rb);
 			if (parent->__subtree_last >= node->__subtree_last)
 				break;
 			parent->__subtree_last = node->__subtree_last;
 			rb = rb_parent(rb);
+		}
 		rb = &hole_node->rb;
 		link = &hole_node->rb.rb_right;
 		leftmost = false;
 	} else {
 		rb = NULL;
 		link = &mm->interval_tree.rb_root.rb_node;
 		leftmost = true;
+	}
 	while (*link) {
 		rb = *link;
 		parent = rb_entry(rb, struct drm_mm_node, rb);
 		if (parent->__subtree_last < node->__subtree_last)
 			parent->__subtree_last = node->__subtree_last;
 		if (node->start < parent->start) {
 			link = &parent->rb.rb_left;
 		} else {
 			link = &parent->rb.rb_right;
 			leftmost = false;
+		}
+	}
 	rb_link_node(&node->rb, rb, link);
 	rb_insert_augmented_cached(&node->rb, &mm->interval_tree, leftmost,
 				   &drm_mm_interval_tree_augment);
+}
 #endif
 #ifdef __NetBSD__
 static int
 compare_hole_addrs(void *cookie, const void *va, const void *vb)
+{
 	const struct drm_mm_node *a = va, *b = vb;
 	const u64 aa = __drm_mm_hole_node_start(a);
 	const u64 ba = __drm_mm_hole_node_start(b);
 	if (aa < ba)
 		return -1;
 	if (aa > ba)
 		return +1;
 	return 0;
+}
 static int
 compare_hole_addr_key(void *cookie, const void *vn, const void *vk)
+{
 	const struct drm_mm_node *n = vn;
 	const u64 a = __drm_mm_hole_node_start(n);
 	const u64 *k = vk;
 	if (a < *k)
 		return -1;
 	if (a > *k)
 		return +1;
 	return 0;
+}
 static const rb_tree_ops_t holes_addr_rb_ops = {
 	.rbto_compare_nodes = compare_hole_addrs,
 	.rbto_compare_key = compare_hole_addr_key,
 	.rbto_node_offset = offsetof(struct drm_mm_node, rb_hole_addr),
 };
 #else
 #define RB_INSERT(root, member, expr) do { \
 	struct rb_node **link = &root.rb_node, *rb = NULL; \
 	u64 x = expr(node); \
 	while (*link) { \
 		rb = *link; \
 		if (x < expr(rb_entry(rb, struct drm_mm_node, member))) \
 			link = &rb->rb_left; \
 		else \
 			link = &rb->rb_right; \
 	} \
 	rb_link_node(&node->member, rb, link); \
 	rb_insert_color(&node->member, &root); \
 } while (0)
 #endif
 #define HOLE_SIZE(NODE) ((NODE)->hole_size)
 #define HOLE_ADDR(NODE) (__drm_mm_hole_node_start(NODE))
 static u64 rb_to_hole_size(struct rb_node *rb)
+{
 	return rb_entry(rb, struct drm_mm_node, rb_hole_size)->hole_size;
+}
 static int
 compare_hole_sizes(void *cookie, const void *va, const void *vb)
+{
 	const struct drm_mm_node *a = va, *b = vb;
 	if (a->hole_size > b->hole_size)
 		return -1;
 	if (a->hole_size < b->hole_size)
 		return +1;
 	return (a < b ? -1 : a > b ? +1 : 0);
+}
 static int
 compare_hole_size_key(void *cookie, const void *vn, const void *vk)
+{
 	const struct drm_mm_node *n = vn;
 	const u64 *k = vk;
 	if (n->hole_size > *k)
 		return -1;
 	if (n->hole_size < *k)
 		return +1;
 	return 0;
+}
 static const rb_tree_ops_t holes_size_rb_ops = {
 	.rbto_compare_nodes = compare_hole_sizes,
 	.rbto_compare_key = compare_hole_size_key,
 	.rbto_node_offset = offsetof(struct drm_mm_node, rb_hole_size),
 };
 static void insert_hole_size(struct rb_root_cached *root,
 			     struct drm_mm_node *node)
+{
 #ifdef __NetBSD__
 	struct drm_mm_node *collision __diagused;
 	collision = rb_tree_insert_node(&root->rb_root.rbr_tree, node);
 	KASSERT(collision == node);
 #else
 	struct rb_node **link = &root->rb_root.rb_node, *rb = NULL;
 	u64 x = node->hole_size;
 	bool first = true;
 	while (*link) {
 		rb = *link;
 		if (x > rb_to_hole_size(rb)) {
 			link = &rb->rb_left;
 		} else {
 			link = &rb->rb_right;
 			first = false;
+		}
+	}
 	rb_link_node(&node->rb_hole_size, rb, link);
 	rb_insert_color_cached(&node->rb_hole_size, root, first);
 #endif
+}
 static void add_hole(struct drm_mm_node *node)
+{
 	struct drm_mm *mm = node->mm;
 	node->hole_size =
 		__drm_mm_hole_node_end(node) - __drm_mm_hole_node_start(node);
 	DRM_MM_BUG_ON(!drm_mm_hole_follows(node));
 	insert_hole_size(&mm->holes_size, node);
 #ifdef __NetBSD__
 	struct drm_mm_node *collision __diagused;
 	collision = rb_tree_insert_node(&mm->holes_addr.rbr_tree, node);
 	KASSERT(collision == node);
 #else
 	RB_INSERT(mm->holes_addr, rb_hole_addr, HOLE_ADDR);
 #endif
 	list_add(&node->hole_stack, &mm->hole_stack);
+}
 static void rm_hole(struct drm_mm_node *node)
+{
 	DRM_MM_BUG_ON(!drm_mm_hole_follows(node));
 	list_del(&node->hole_stack);
 	rb_erase_cached(&node->rb_hole_size, &node->mm->holes_size);
 	rb_erase(&node->rb_hole_addr, &node->mm->holes_addr);
 	node->hole_size = 0;
 	DRM_MM_BUG_ON(drm_mm_hole_follows(node));
+}
 static inline struct drm_mm_node *rb_hole_size_to_node(struct rb_node *rb)
+{
 	return rb_entry_safe(rb, struct drm_mm_node, rb_hole_size);
+}
 static inline struct drm_mm_node *rb_hole_addr_to_node(struct rb_node *rb)
+{
 	return rb_entry_safe(rb, struct drm_mm_node, rb_hole_addr);
+}
 static inline u64 rb_hole_size(struct rb_node *rb)
+{
 	return rb_entry(rb, struct drm_mm_node, rb_hole_size)->hole_size;
+}
 static struct drm_mm_node *best_hole(struct drm_mm *mm, u64 size)
+{
 #ifdef __NetBSD__
-	return rb_tree_find_node_leq(&mm->holes_size.rb_root.rbr_tree, &size);
+	struct drm_mm_node *best;
 	best = rb_tree_find_node_leq(&mm->holes_size.rb_root.rbr_tree, &size);
 	KASSERT(best == NULL || size <= best->hole_size);
 	return best;
 #else
 	struct rb_node *rb = mm->holes_size.rb_root.rb_node;
 	struct drm_mm_node *best = NULL;
 	do {
 		struct drm_mm_node *node =
 			rb_entry(rb, struct drm_mm_node, rb_hole_size);
 		if (size <= node->hole_size) {
 			best = node;
 			rb = rb->rb_right;
 		} else {
 			rb = rb->rb_left;
+		}
 	} while (rb);
 	return best;
 #endif
+}
 static struct drm_mm_node *find_hole(struct drm_mm *mm, u64 addr)
+{
 #ifdef __NetBSD__
 	return rb_tree_find_node_leq(&mm->holes_addr.rbr_tree, &addr);
 #else
 	struct rb_node *rb = mm->holes_addr.rb_node;
 	struct drm_mm_node *node = NULL;
 	while (rb) {
 		u64 hole_start;
 		node = rb_hole_addr_to_node(rb);
 		hole_start = __drm_mm_hole_node_start(node);
 		if (addr < hole_start)
 			rb = node->rb_hole_addr.rb_left;
 		else if (addr > hole_start + node->hole_size)
 			rb = node->rb_hole_addr.rb_right;
 		else
 			break;
+	}
 	return node;
 #endif
+}
 static struct drm_mm_node *
 first_hole(struct drm_mm *mm,
 	   u64 start, u64 end, u64 size,
 	   enum drm_mm_insert_mode mode)
+{
 	switch (mode) {
 	default:
 	case DRM_MM_INSERT_BEST:
 		return best_hole(mm, size);
 	case DRM_MM_INSERT_LOW:
 		return find_hole(mm, start);
 	case DRM_MM_INSERT_HIGH:
 		return find_hole(mm, end);
 	case DRM_MM_INSERT_EVICT:
 		return list_first_entry_or_null(&mm->hole_stack,
 						struct drm_mm_node,
 						hole_stack);
+	}
+}
 static struct drm_mm_node *
 next_hole(struct drm_mm *mm,
 	  struct drm_mm_node *node,
 	  enum drm_mm_insert_mode mode)
+{
 	switch (mode) {
 	default:
 	case DRM_MM_INSERT_BEST:
 #ifdef __NetBSD__
 		return RB_TREE_PREV(&mm->holes_size.rb_root.rbr_tree, node);
 #else
 		return rb_hole_size_to_node(rb_prev(&node->rb_hole_size));
 #endif
 	case DRM_MM_INSERT_LOW:
 #ifdef __NetBSD__
 		return RB_TREE_NEXT(&mm->holes_addr.rbr_tree, node);
 #else
 		return rb_hole_addr_to_node(rb_next(&node->rb_hole_addr));
 #endif
 	case DRM_MM_INSERT_HIGH:
 #ifdef __NetBSD__
 		return RB_TREE_PREV(&mm->holes_addr.rbr_tree, node);
 #else
 		return rb_hole_addr_to_node(rb_prev(&node->rb_hole_addr));
 #endif
 	case DRM_MM_INSERT_EVICT:
 		node = list_next_entry(node, hole_stack);
 		return &node->hole_stack == &mm->hole_stack ? NULL : node;
+	}
+}
 /**
  * drm_mm_reserve_node - insert an pre-initialized node
  * @mm: drm_mm allocator to insert @node into
  * @node: drm_mm_node to insert
+ *
  * This functions inserts an already set-up &drm_mm_node into the allocator,
  * meaning that start, size and color must be set by the caller. All other
  * fields must be cleared to 0. This is useful to initialize the allocator with
  * preallocated objects which must be set-up before the range allocator can be
  * set-up, e.g. when taking over a firmware framebuffer.
+ *
  * Returns:
  * 0 on success, -ENOSPC if there's no hole where @node is.
  */
 int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node)
+{
 	u64 end = node->start + node->size;
 	struct drm_mm_node *hole;
 	u64 hole_start, hole_end;
 	u64 adj_start, adj_end;
 	end = node->start + node->size;
 	if (unlikely(end <= node->start))
 		return -ENOSPC;
 	/* Find the relevant hole to add our node to */
 	hole = find_hole(mm, node->start);
 	if (!hole)
 		return -ENOSPC;
 	adj_start = hole_start = __drm_mm_hole_node_start(hole);
 	adj_end = hole_end = hole_start + hole->hole_size;
 	if (mm->color_adjust)
 		mm->color_adjust(hole, node->color, &adj_start, &adj_end);
 	if (adj_start > node->start || adj_end < end)
 		return -ENOSPC;
 	node->mm = mm;
 	__set_bit(DRM_MM_NODE_ALLOCATED_BIT, &node->flags);
 	list_add(&node->node_list, &hole->node_list);
 #ifndef __NetBSD__
 	drm_mm_interval_tree_add_node(hole, node);
 #endif
 	node->hole_size = 0;
 	rm_hole(hole);
 	if (node->start > hole_start)
 		add_hole(hole);
 	if (end < hole_end)
 		add_hole(node);
 	save_stack(node);
 	return 0;
+}
 EXPORT_SYMBOL(drm_mm_reserve_node);
 static u64 rb_to_hole_size_or_zero(struct rb_node *rb)
+{
 	return rb ? rb_to_hole_size(rb) : 0;
+}
 /**
  * drm_mm_insert_node_in_range - ranged search for space and insert @node
  * @mm: drm_mm to allocate from
  * @node: preallocate node to insert
  * @size: size of the allocation
  * @alignment: alignment of the allocation
  * @color: opaque tag value to use for this node
  * @range_start: start of the allowed range for this node
  * @range_end: end of the allowed range for this node
  * @mode: fine-tune the allocation search and placement
+ *
  * The preallocated @node must be cleared to 0.
+ *
  * Returns:
  * 0 on success, -ENOSPC if there's no suitable hole.
  */
 int drm_mm_insert_node_in_range(struct drm_mm * const mm,
 				struct drm_mm_node * const node,
 				u64 size, u64 alignment,
 				unsigned long color,
 				u64 range_start, u64 range_end,
 				enum drm_mm_insert_mode mode)
+{
 	struct drm_mm_node *hole;
 	u64 remainder_mask;
 	bool once;
 	DRM_MM_BUG_ON(range_start > range_end);
 	if (unlikely(size == 0 || range_end - range_start < size))
 		return -ENOSPC;
 	if (rb_to_hole_size_or_zero(rb_first_cached(&mm->holes_size)) < size)
 		return -ENOSPC;
 	if (alignment <= 1)
 		alignment = 0;
 	once = mode & DRM_MM_INSERT_ONCE;
 	mode &= ~DRM_MM_INSERT_ONCE;
 	remainder_mask = is_power_of_2(alignment) ? alignment - 1 : 0;
 	for (hole = first_hole(mm, range_start, range_end, size, mode);
 	     hole;
 	     hole = once ? NULL : next_hole(mm, hole, mode)) {
 		u64 hole_start = __drm_mm_hole_node_start(hole);
 		u64 hole_end = hole_start + hole->hole_size;
 		u64 adj_start, adj_end;
 		u64 col_start, col_end;
 		if (mode == DRM_MM_INSERT_LOW && hole_start >= range_end)
 			break;
 		if (mode == DRM_MM_INSERT_HIGH && hole_end <= range_start)
 			break;
 		col_start = hole_start;
 		col_end = hole_end;
 		if (mm->color_adjust)
 			mm->color_adjust(hole, color, &col_start, &col_end);
 		adj_start = max(col_start, range_start);
 		adj_end = min(col_end, range_end);
 		if (adj_end <= adj_start || adj_end - adj_start < size)
 			continue;
 		if (mode == DRM_MM_INSERT_HIGH)
 			adj_start = adj_end - size;
 		if (alignment) {
 			u64 rem;
 			if (likely(remainder_mask))
 				rem = adj_start & remainder_mask;
 			else
 				div64_u64_rem(adj_start, alignment, &rem);
 			if (rem) {
 				adj_start -= rem;
 				if (mode != DRM_MM_INSERT_HIGH)
 					adj_start += alignment;
 				if (adj_start < max(col_start, range_start) ||
 				    min(col_end, range_end) - adj_start < size)
 					continue;
 				if (adj_end <= adj_start ||
 				    adj_end - adj_start < size)
 					continue;
+			}
+		}
 		node->mm = mm;
 		node->size = size;
 		node->start = adj_start;
 		node->color = color;
 		node->hole_size = 0;
 		__set_bit(DRM_MM_NODE_ALLOCATED_BIT, &node->flags);
 		list_add(&node->node_list, &hole->node_list);
 #ifndef __NetBSD__
 		drm_mm_interval_tree_add_node(hole, node);
 #endif
 		rm_hole(hole);
 		if (adj_start > hole_start)
 			add_hole(hole);
 		if (adj_start + size < hole_end)
 			add_hole(node);
 		save_stack(node);
 		return 0;
+	}
 	return -ENOSPC;
+}
 EXPORT_SYMBOL(drm_mm_insert_node_in_range);
 static inline bool drm_mm_node_scanned_block(const struct drm_mm_node *node)
+{
 	return test_bit(DRM_MM_NODE_SCANNED_BIT, &node->flags);
+}
 /**
  * drm_mm_remove_node - Remove a memory node from the allocator.
  * @node: drm_mm_node to remove
+ *
  * This just removes a node from its drm_mm allocator. The node does not need to
  * be cleared again before it can be re-inserted into this or any other drm_mm
  * allocator. It is a bug to call this function on a unallocated node.
  */
 void drm_mm_remove_node(struct drm_mm_node *node)
+{
 	struct drm_mm *mm = node->mm;
 	struct drm_mm_node *prev_node;
 	DRM_MM_BUG_ON(!drm_mm_node_allocated(node));
 	DRM_MM_BUG_ON(drm_mm_node_scanned_block(node));
 	prev_node = list_prev_entry(node, node_list);
 	if (drm_mm_hole_follows(node))
 		rm_hole(node);
 #ifdef __NetBSD__
 	__USE(mm);
 #else
 	drm_mm_interval_tree_remove(node, &mm->interval_tree);
 #endif
 	list_del(&node->node_list);
 	if (drm_mm_hole_follows(prev_node))
 		rm_hole(prev_node);
 	add_hole(prev_node);
 	clear_bit_unlock(DRM_MM_NODE_ALLOCATED_BIT, &node->flags);
+}
 EXPORT_SYMBOL(drm_mm_remove_node);
 /**
  * drm_mm_replace_node - move an allocation from @old to @new
  * @old: drm_mm_node to remove from the allocator
  * @new: drm_mm_node which should inherit @old's allocation
+ *
  * This is useful for when drivers embed the drm_mm_node structure and hence
  * can't move allocations by reassigning pointers. It's a combination of remove
  * and insert with the guarantee that the allocation start will match.
  */
 void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
+{
 	struct drm_mm *mm = old->mm;
 	DRM_MM_BUG_ON(!drm_mm_node_allocated(old));
 	*new = *old;
 	__set_bit(DRM_MM_NODE_ALLOCATED_BIT, &new->flags);
 	list_replace(&old->node_list, &new->node_list);
 #ifndef __NetBSD__
 	rb_replace_node_cached(&old->rb, &new->rb, &mm->interval_tree);
 #endif
 	if (drm_mm_hole_follows(old)) {
 		list_replace(&old->hole_stack, &new->hole_stack);
 		rb_replace_node_cached(&old->rb_hole_size,
 				       &new->rb_hole_size,
 				       &mm->holes_size);
 		rb_replace_node(&old->rb_hole_addr,
 				&new->rb_hole_addr,
 				&mm->holes_addr);
+	}
 	clear_bit_unlock(DRM_MM_NODE_ALLOCATED_BIT, &old->flags);
+}
 EXPORT_SYMBOL(drm_mm_replace_node);
 /**
  * DOC: lru scan roster
+ *
  * Very often GPUs need to have continuous allocations for a given object. When
  * evicting objects to make space for a new one it is therefore not most
  * efficient when we simply start to select all objects from the tail of an LRU
  * until there's a suitable hole: Especially for big objects or nodes that
  * otherwise have special allocation constraints there's a good chance we evict
  * lots of (smaller) objects unnecessarily.
+ *
  * The DRM range allocator supports this use-case through the scanning
  * interfaces. First a scan operation needs to be initialized with
  * drm_mm_scan_init() or drm_mm_scan_init_with_range(). The driver adds
  * objects to the roster, probably by walking an LRU list, but this can be
  * freely implemented. Eviction candiates are added using
  * drm_mm_scan_add_block() until a suitable hole is found or there are no
  * further evictable objects. Eviction roster metadata is tracked in &struct
  * drm_mm_scan.
+ *
  * The driver must walk through all objects again in exactly the reverse
  * order to restore the allocator state. Note that while the allocator is used
  * in the scan mode no other operation is allowed.
+ *
  * Finally the driver evicts all objects selected (drm_mm_scan_remove_block()
  * reported true) in the scan, and any overlapping nodes after color adjustment
  * (drm_mm_scan_color_evict()). Adding and removing an object is O(1), and
  * since freeing a node is also O(1) the overall complexity is
  * O(scanned_objects). So like the free stack which needs to be walked before a
  * scan operation even begins this is linear in the number of objects. It
  * doesn't seem to hurt too badly.
  */
 /**
  * drm_mm_scan_init_with_range - initialize range-restricted lru scanning
  * @scan: scan state
  * @mm: drm_mm to scan
  * @size: size of the allocation
  * @alignment: alignment of the allocation
  * @color: opaque tag value to use for the allocation
  * @start: start of the allowed range for the allocation
  * @end: end of the allowed range for the allocation
  * @mode: fine-tune the allocation search and placement
+ *
  * This simply sets up the scanning routines with the parameters for the desired
  * hole.
+ *
  * Warning:
  * As long as the scan list is non-empty, no other operations than
  * adding/removing nodes to/from the scan list are allowed.
  */
 void drm_mm_scan_init_with_range(struct drm_mm_scan *scan,
 				 struct drm_mm *mm,
 				 u64 size,
 				 u64 alignment,
 				 unsigned long color,
 				 u64 start,
 				 u64 end,
 				 enum drm_mm_insert_mode mode)
+{
 	DRM_MM_BUG_ON(start >= end);
 	DRM_MM_BUG_ON(!size || size > end - start);
 	DRM_MM_BUG_ON(mm->scan_active);
 	scan->mm = mm;
 	if (alignment <= 1)
 		alignment = 0;
 	scan->color = color;
 	scan->alignment = alignment;
 	scan->remainder_mask = is_power_of_2(alignment) ? alignment - 1 : 0;
 	scan->size = size;
 	scan->mode = mode;
 	DRM_MM_BUG_ON(end <= start);
 	scan->range_start = start;
 	scan->range_end = end;
 	scan->hit_start = U64_MAX;
 	scan->hit_end = 0;
+}
 EXPORT_SYMBOL(drm_mm_scan_init_with_range);
 /**
  * drm_mm_scan_add_block - add a node to the scan list
  * @scan: the active drm_mm scanner
  * @node: drm_mm_node to add
+ *
  * Add a node to the scan list that might be freed to make space for the desired
  * hole.
+ *
  * Returns:
  * True if a hole has been found, false otherwise.
  */
 bool drm_mm_scan_add_block(struct drm_mm_scan *scan,
 			   struct drm_mm_node *node)
+{
 	struct drm_mm *mm = scan->mm;
 	struct drm_mm_node *hole;
 	u64 hole_start, hole_end;
 	u64 col_start, col_end;
 	u64 adj_start, adj_end;
 	DRM_MM_BUG_ON(node->mm != mm);
 	DRM_MM_BUG_ON(!drm_mm_node_allocated(node));
 	DRM_MM_BUG_ON(drm_mm_node_scanned_block(node));
 	__set_bit(DRM_MM_NODE_SCANNED_BIT, &node->flags);
 	mm->scan_active++;
 	/* Remove this block from the node_list so that we enlarge the hole
 	 * (distance between the end of our previous node and the start of
 	 * or next), without poisoning the link so that we can restore it
 	 * later in drm_mm_scan_remove_block().
 	 */
 	hole = list_prev_entry(node, node_list);
 	DRM_MM_BUG_ON(list_next_entry(hole, node_list) != node);
 	__list_del_entry(&node->node_list);
 	hole_start = __drm_mm_hole_node_start(hole);
 	hole_end = __drm_mm_hole_node_end(hole);
 	col_start = hole_start;
 	col_end = hole_end;
 	if (mm->color_adjust)
 		mm->color_adjust(hole, scan->color, &col_start, &col_end);
 	adj_start = max(col_start, scan->range_start);
 	adj_end = min(col_end, scan->range_end);
 	if (adj_end <= adj_start || adj_end - adj_start < scan->size)
 		return false;
 	if (scan->mode == DRM_MM_INSERT_HIGH)
 		adj_start = adj_end - scan->size;
 	if (scan->alignment) {
 		u64 rem;
 		if (likely(scan->remainder_mask))
 			rem = adj_start & scan->remainder_mask;
 		else
 			div64_u64_rem(adj_start, scan->alignment, &rem);
 		if (rem) {
 			adj_start -= rem;
 			if (scan->mode != DRM_MM_INSERT_HIGH)
 				adj_start += scan->alignment;
 			if (adj_start < max(col_start, scan->range_start) ||
 			    min(col_end, scan->range_end) - adj_start < scan->size)
 				return false;
 			if (adj_end <= adj_start ||
 			    adj_end - adj_start < scan->size)
 				return false;
+		}
+	}
 	scan->hit_start = adj_start;
 	scan->hit_end = adj_start + scan->size;
 	DRM_MM_BUG_ON(scan->hit_start >= scan->hit_end);
 	DRM_MM_BUG_ON(scan->hit_start < hole_start);
 	DRM_MM_BUG_ON(scan->hit_end > hole_end);
 	return true;
+}
 EXPORT_SYMBOL(drm_mm_scan_add_block);
 /**
  * drm_mm_scan_remove_block - remove a node from the scan list
  * @scan: the active drm_mm scanner
  * @node: drm_mm_node to remove
+ *
  * Nodes **must** be removed in exactly the reverse order from the scan list as
  * they have been added (e.g. using list_add() as they are added and then
  * list_for_each() over that eviction list to remove), otherwise the internal
  * state of the memory manager will be corrupted.
+ *
  * When the scan list is empty, the selected memory nodes can be freed. An
  * immediately following drm_mm_insert_node_in_range_generic() or one of the
  * simpler versions of that function with !DRM_MM_SEARCH_BEST will then return
  * the just freed block (because it's at the top of the free_stack list).
+ *
  * Returns:
  * True if this block should be evicted, false otherwise. Will always
  * return false when no hole has been found.
  */
 bool drm_mm_scan_remove_block(struct drm_mm_scan *scan,
 			      struct drm_mm_node *node)
+{
 	struct drm_mm_node *prev_node;
 	DRM_MM_BUG_ON(node->mm != scan->mm);
 	DRM_MM_BUG_ON(!drm_mm_node_scanned_block(node));
 	__clear_bit(DRM_MM_NODE_SCANNED_BIT, &node->flags);
 	DRM_MM_BUG_ON(!node->mm->scan_active);
 	node->mm->scan_active--;
 	/* During drm_mm_scan_add_block() we decoupled this node leaving
 	 * its pointers intact. Now that the caller is walking back along
 	 * the eviction list we can restore this block into its rightful
 	 * place on the full node_list. To confirm that the caller is walking
 	 * backwards correctly we check that prev_node->next == node->next,
 	 * i.e. both believe the same node should be on the other side of the
 	 * hole.
 	 */
 	prev_node = list_prev_entry(node, node_list);
 	DRM_MM_BUG_ON(list_next_entry(prev_node, node_list) !=
 		      list_next_entry(node, node_list));
 	list_add(&node->node_list, &prev_node->node_list);
 	return (node->start + node->size > scan->hit_start &&
 		node->start < scan->hit_end);
+}
 EXPORT_SYMBOL(drm_mm_scan_remove_block);
 /**
  * drm_mm_scan_color_evict - evict overlapping nodes on either side of hole
  * @scan: drm_mm scan with target hole
+ *
  * After completing an eviction scan and removing the selected nodes, we may
  * need to remove a few more nodes from either side of the target hole if
  * mm.color_adjust is being used.
+ *
  * Returns:
  * A node to evict, or NULL if there are no overlapping nodes.
  */
 struct drm_mm_node *drm_mm_scan_color_evict(struct drm_mm_scan *scan)
+{
 	struct drm_mm *mm = scan->mm;
 	struct drm_mm_node *hole;
 	u64 hole_start, hole_end;
 	DRM_MM_BUG_ON(list_empty(&mm->hole_stack));
 	if (!mm->color_adjust)
 		return NULL;
 	/*
 	 * The hole found during scanning should ideally be the first element
 	 * in the hole_stack list, but due to side-effects in the driver it
 	 * may not be.
 	 */
 	list_for_each_entry(hole, &mm->hole_stack, hole_stack) {
 		hole_start = __drm_mm_hole_node_start(hole);
 		hole_end = hole_start + hole->hole_size;
 		if (hole_start <= scan->hit_start &&
 		    hole_end >= scan->hit_end)
 			break;
+	}
 	/* We should only be called after we found the hole previously */
 	DRM_MM_BUG_ON(&hole->hole_stack == &mm->hole_stack);
 	if (unlikely(&hole->hole_stack == &mm->hole_stack))
 		return NULL;
 	DRM_MM_BUG_ON(hole_start > scan->hit_start);
 	DRM_MM_BUG_ON(hole_end < scan->hit_end);
 	mm->color_adjust(hole, scan->color, &hole_start, &hole_end);
 	if (hole_start > scan->hit_start)
 		return hole;
 	if (hole_end < scan->hit_end)
 		return list_next_entry(hole, node_list);
 	return NULL;
+}
 EXPORT_SYMBOL(drm_mm_scan_color_evict);
 /**
  * drm_mm_init - initialize a drm-mm allocator
  * @mm: the drm_mm structure to initialize
  * @start: start of the range managed by @mm
  * @size: end of the range managed by @mm
+ *
  * Note that @mm must be cleared to 0 before calling this function.
  */
 void drm_mm_init(struct drm_mm *mm, u64 start, u64 size)
+{
 	DRM_MM_BUG_ON(start + size <= start);
 	mm->color_adjust = NULL;
 	INIT_LIST_HEAD(&mm->hole_stack);
 #ifdef __NetBSD__
 	/* XXX interval tree */
 	rb_tree_init(&mm->holes_size.rb_root.rbr_tree, &holes_size_rb_ops);
 	rb_tree_init(&mm->holes_addr.rbr_tree, &holes_addr_rb_ops);
 #else
 	mm->interval_tree = RB_ROOT_CACHED;
 	mm->holes_size = RB_ROOT_CACHED;
 	mm->holes_addr = RB_ROOT;
 #endif
 	/* Clever trick to avoid a special case in the free hole tracking. */
 	INIT_LIST_HEAD(&mm->head_node.node_list);
 	mm->head_node.flags = 0;
 	mm->head_node.mm = mm;
 	mm->head_node.start = start + size;
 	mm->head_node.size = -size;
 	add_hole(&mm->head_node);
 	mm->scan_active = 0;
+}
 EXPORT_SYMBOL(drm_mm_init);
 /**
  * drm_mm_takedown - clean up a drm_mm allocator
  * @mm: drm_mm allocator to clean up
+ *
  * Note that it is a bug to call this function on an allocator which is not
  * clean.
  */
 void drm_mm_takedown(struct drm_mm *mm)
+{
 	if (WARN(!drm_mm_clean(mm),
 		 "Memory manager not clean during takedown.\n"))
 		show_leaks(mm);
+}
 EXPORT_SYMBOL(drm_mm_takedown);
 static u64 drm_mm_dump_hole(struct drm_printer *p, const struct drm_mm_node *entry)
+{
 	u64 start, size;
 	size = entry->hole_size;
 	if (size) {
 		start = drm_mm_hole_node_start(entry);
 		drm_printf(p, "%#018"PRIx64"-%#018"PRIx64": %"PRIu64": free\n",
 			   start, start + size, size);
+	}
 	return size;
+}
 /**
  * drm_mm_print - print allocator state
  * @mm: drm_mm allocator to print
  * @p: DRM printer to use
  */
 void drm_mm_print(const struct drm_mm *mm, struct drm_printer *p)
+{
 	const struct drm_mm_node *entry;
 	u64 total_used = 0, total_free = 0, total = 0;
 	total_free += drm_mm_dump_hole(p, &mm->head_node);
 	drm_mm_for_each_node(entry, mm) {
 		drm_printf(p, "%#018"PRIx64"-%#018"PRIx64": %"PRIu64": used\n", entry->start,
 			   entry->start + entry->size, entry->size);
 		total_used += entry->size;
 		total_free += drm_mm_dump_hole(p, entry);
+	}
 	total = total_free + total_used;
 	drm_printf(p, "total: %"PRIu64", used %"PRIu64" free %"PRIu64"\n", total,
 		   total_used, total_free);
+}
 EXPORT_SYMBOL(drm_mm_print);