Update inteldrm(4) to code based on Linux 4.4.70. This brings us support for

Skylake and Cherryview and better support for Broadwell and Valleyview.  Also
adds MST support.  Some tweaks to the TTM code and radeondrm(4) to keep it
working with the updated generic DRM code needed for inteldrm(4).

Tested by many.

1 files changed, 335 insertions, 246 deletions

diff --git a/sys/dev/pci/drm/drm_mm.c b/sys/dev/pci/drm/drm_mm.c
index 5cff9e248c6..7bf268a967d 100644
--- a/sys/dev/pci/drm/drm_mm.c
+++ b/sys/dev/pci/drm/drm_mm.c
@@ -1,4 +1,3 @@
-/*	$OpenBSD: drm_mm.c,v 1.7 2015/09/23 23:12:11 kettenis Exp $	*/
 /**************************************************************************
  *
  * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND., USA.
@@ -42,86 +41,106 @@
  * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
  */
 
-#include "drmP.h"
-#include "drm_mm.h"
-
-#define MM_UNUSED_TARGET 4
-
-static struct drm_mm_node *drm_mm_kmalloc(struct drm_mm *mm, int atomic)
-{
-	struct drm_mm_node *child;
-
-	if (atomic)
-		child = kzalloc(sizeof(*child), GFP_ATOMIC);
-	else
-		child = kzalloc(sizeof(*child), GFP_KERNEL);
-
-	if (unlikely(child == NULL)) {
-		spin_lock(&mm->unused_lock);
-		if (list_empty(&mm->unused_nodes))
-			child = NULL;
-		else {
-			child =
-			    list_entry(mm->unused_nodes.next,
-				       struct drm_mm_node, node_list);
-			list_del(&child->node_list);
-			--mm->num_unused;
-		}
-		spin_unlock(&mm->unused_lock);
-	}
-	return child;
-}
+#include <dev/pci/drm/drmP.h>
+#include <dev/pci/drm/drm_mm.h>
+#ifdef __linux__
+#include <linux/slab.h>
+#include <linux/seq_file.h>
+#include <linux/export.h>
+#endif
 
-/* drm_mm_pre_get() - pre allocate drm_mm_node structure
- * drm_mm:	memory manager struct we are pre-allocating for
+/**
+ * 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 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
+ * depencies 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. Further more every &drm_mm_node has a color value (which is just an
+ * opaqua 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.
  *
- * Returns 0 on success or -ENOMEM if allocation fails.
+ * 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.
  */
-int drm_mm_pre_get(struct drm_mm *mm)
-{
-	struct drm_mm_node *node;
-
-	spin_lock(&mm->unused_lock);
-	while (mm->num_unused < MM_UNUSED_TARGET) {
-		spin_unlock(&mm->unused_lock);
-		node = kzalloc(sizeof(*node), GFP_KERNEL);
-		spin_lock(&mm->unused_lock);
-
-		if (unlikely(node == NULL)) {
-			int ret = (mm->num_unused < 2) ? -ENOMEM : 0;
-			spin_unlock(&mm->unused_lock);
-			return ret;
-		}
-		++mm->num_unused;
-		list_add_tail(&node->node_list, &mm->unused_nodes);
-	}
-	spin_unlock(&mm->unused_lock);
-	return 0;
-}
-EXPORT_SYMBOL(drm_mm_pre_get);
+
+static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
+						u64 size,
+						unsigned alignment,
+						unsigned long color,
+						enum drm_mm_search_flags flags);
+static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm,
+						u64 size,
+						unsigned alignment,
+						unsigned long color,
+						u64 start,
+						u64 end,
+						enum drm_mm_search_flags flags);
 
 static void drm_mm_insert_helper(struct drm_mm_node *hole_node,
 				 struct drm_mm_node *node,
-				 unsigned long size, unsigned alignment,
-				 unsigned long color)
+				 u64 size, unsigned alignment,
+				 unsigned long color,
+				 enum drm_mm_allocator_flags flags)
 {
 	struct drm_mm *mm = hole_node->mm;
-	unsigned long hole_start = drm_mm_hole_node_start(hole_node);
-	unsigned long hole_end = drm_mm_hole_node_end(hole_node);
-	unsigned long adj_start = hole_start;
-	unsigned long adj_end = hole_end;
+	u64 hole_start = drm_mm_hole_node_start(hole_node);
+	u64 hole_end = drm_mm_hole_node_end(hole_node);
+	u64 adj_start = hole_start;
+	u64 adj_end = hole_end;
 
 	BUG_ON(node->allocated);
 
 	if (mm->color_adjust)
 		mm->color_adjust(hole_node, color, &adj_start, &adj_end);
 
+	if (flags & DRM_MM_CREATE_TOP)
+		adj_start = adj_end - size;
+
 	if (alignment) {
-		unsigned tmp = adj_start % alignment;
-		if (tmp)
-			adj_start += alignment - tmp;
+		u64 tmp = adj_start;
+		unsigned rem;
+
+		rem = do_div(tmp, alignment);
+		if (rem) {
+			if (flags & DRM_MM_CREATE_TOP)
+				adj_start -= rem;
+			else
+				adj_start += alignment - rem;
+		}
 	}
 
+	BUG_ON(adj_start < hole_start);
+	BUG_ON(adj_end > hole_end);
+
 	if (adj_start == hole_start) {
 		hole_node->hole_follows = 0;
 		list_del(&hole_node->hole_stack);
@@ -145,15 +164,31 @@ static void drm_mm_insert_helper(struct drm_mm_node *hole_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. 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)
 {
 	struct drm_mm_node *hole;
-	unsigned long end = node->start + node->size;
-	unsigned long hole_start;
-	unsigned long hole_end;
+	u64 end;
+	u64 hole_start;
+	u64 hole_end;
 
 	BUG_ON(node == NULL);
 
+	end = node->start + node->size;
+
 	/* Find the relevant hole to add our node to */
 	drm_mm_for_each_hole(hole, mm, hole_start, hole_end) {
 		if (hole_start > node->start || hole_end < end)
@@ -179,63 +214,55 @@ int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node)
 		return 0;
 	}
 
-	WARN(1, "no hole found for node 0x%lx + 0x%lx\n",
-	     node->start, node->size);
 	return -ENOSPC;
 }
 EXPORT_SYMBOL(drm_mm_reserve_node);
 
-struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *hole_node,
-					     unsigned long size,
-					     unsigned alignment,
-					     unsigned long color,
-					     int atomic)
-{
-	struct drm_mm_node *node;
-
-	node = drm_mm_kmalloc(hole_node->mm, atomic);
-	if (unlikely(node == NULL))
-		return NULL;
-
-	drm_mm_insert_helper(hole_node, node, size, alignment, color);
-
-	return node;
-}
-EXPORT_SYMBOL(drm_mm_get_block_generic);
-
 /**
- * Search for free space and insert a preallocated memory node. Returns
- * -ENOSPC if no suitable free area is available. The preallocated memory node
- * must be cleared.
+ * drm_mm_insert_node_generic - 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
+ * @sflags: flags to fine-tune the allocation search
+ * @aflags: flags to fine-tune the allocation behavior
+ *
+ * The preallocated node must be cleared to 0.
+ *
+ * Returns:
+ * 0 on success, -ENOSPC if there's no suitable hole.
  */
 int drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node,
-			       unsigned long size, unsigned alignment,
+			       u64 size, unsigned alignment,
 			       unsigned long color,
-			       enum drm_mm_search_flags flags)
+			       enum drm_mm_search_flags sflags,
+			       enum drm_mm_allocator_flags aflags)
 {
 	struct drm_mm_node *hole_node;
 
 	hole_node = drm_mm_search_free_generic(mm, size, alignment,
-					       color, flags);
+					       color, sflags);
 	if (!hole_node)
 		return -ENOSPC;
 
-	drm_mm_insert_helper(hole_node, node, size, alignment, color);
+	drm_mm_insert_helper(hole_node, node, size, alignment, color, aflags);
 	return 0;
 }
 EXPORT_SYMBOL(drm_mm_insert_node_generic);
 
 static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
 				       struct drm_mm_node *node,
-				       unsigned long size, unsigned alignment,
+				       u64 size, unsigned alignment,
 				       unsigned long color,
-				       unsigned long start, unsigned long end)
+				       u64 start, u64 end,
+				       enum drm_mm_allocator_flags flags)
 {
 	struct drm_mm *mm = hole_node->mm;
-	unsigned long hole_start = drm_mm_hole_node_start(hole_node);
-	unsigned long hole_end = drm_mm_hole_node_end(hole_node);
-	unsigned long adj_start = hole_start;
-	unsigned long adj_end = hole_end;
+	u64 hole_start = drm_mm_hole_node_start(hole_node);
+	u64 hole_end = drm_mm_hole_node_end(hole_node);
+	u64 adj_start = hole_start;
+	u64 adj_end = hole_end;
 
 	BUG_ON(!hole_node->hole_follows || node->allocated);
 
@@ -247,10 +274,20 @@ static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
 	if (mm->color_adjust)
 		mm->color_adjust(hole_node, color, &adj_start, &adj_end);
 
+	if (flags & DRM_MM_CREATE_TOP)
+		adj_start = adj_end - size;
+
 	if (alignment) {
-		unsigned tmp = adj_start % alignment;
-		if (tmp)
-			adj_start += alignment - tmp;
+		u64 tmp = adj_start;
+		unsigned rem;
+
+		rem = do_div(tmp, alignment);
+		if (rem) {
+			if (flags & DRM_MM_CREATE_TOP)
+				adj_start -= rem;
+			else
+				adj_start += alignment - rem;
+		}
 	}
 
 	if (adj_start == hole_start) {
@@ -267,6 +304,8 @@ static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
 	INIT_LIST_HEAD(&node->hole_stack);
 	list_add(&node->node_list, &hole_node->node_list);
 
+	BUG_ON(node->start < start);
+	BUG_ON(node->start < adj_start);
 	BUG_ON(node->start + node->size > adj_end);
 	BUG_ON(node->start + node->size > end);
 
@@ -277,54 +316,52 @@ static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
 	}
 }
 
-struct drm_mm_node *drm_mm_get_block_range_generic(struct drm_mm_node *hole_node,
-						unsigned long size,
-						unsigned alignment,
-						unsigned long color,
-						unsigned long start,
-						unsigned long end,
-						int atomic)
-{
-	struct drm_mm_node *node;
-
-	node = drm_mm_kmalloc(hole_node->mm, atomic);
-	if (unlikely(node == NULL))
-		return NULL;
-
-	drm_mm_insert_helper_range(hole_node, node, size, alignment, color,
-				   start, end);
-
-	return node;
-}
-EXPORT_SYMBOL(drm_mm_get_block_range_generic);
-
 /**
- * Search for free space and insert a preallocated memory node. Returns
- * -ENOSPC if no suitable free area is available. This is for range
- * restricted allocations. The preallocated memory node must be cleared.
+ * drm_mm_insert_node_in_range_generic - 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
+ * @start: start of the allowed range for this node
+ * @end: end of the allowed range for this node
+ * @sflags: flags to fine-tune the allocation search
+ * @aflags: flags to fine-tune the allocation behavior
+ *
+ * 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_generic(struct drm_mm *mm, struct drm_mm_node *node,
-					unsigned long size, unsigned alignment, unsigned long color,
-					unsigned long start, unsigned long end,
-					enum drm_mm_search_flags flags)
+					u64 size, unsigned alignment,
+					unsigned long color,
+					u64 start, u64 end,
+					enum drm_mm_search_flags sflags,
+					enum drm_mm_allocator_flags aflags)
 {
 	struct drm_mm_node *hole_node;
 
 	hole_node = drm_mm_search_free_in_range_generic(mm,
 							size, alignment, color,
-							start, end, flags);
+							start, end, sflags);
 	if (!hole_node)
 		return -ENOSPC;
 
 	drm_mm_insert_helper_range(hole_node, node,
 				   size, alignment, color,
-				   start, end);
+				   start, end, aflags);
 	return 0;
 }
 EXPORT_SYMBOL(drm_mm_insert_node_in_range_generic);
 
 /**
- * Remove a memory node from the allocator.
+ * 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 un-allocated node.
  */
 void drm_mm_remove_node(struct drm_mm_node *node)
 {
@@ -360,61 +397,44 @@ void drm_mm_remove_node(struct drm_mm_node *node)
 }
 EXPORT_SYMBOL(drm_mm_remove_node);
 
-/*
- * Remove a memory node from the allocator and free the allocated struct
- * drm_mm_node. Only to be used on a struct drm_mm_node obtained by one of the
- * drm_mm_get_block functions.
- */
-void drm_mm_put_block(struct drm_mm_node *node)
-{
-
-	struct drm_mm *mm = node->mm;
-
-	drm_mm_remove_node(node);
-
-	spin_lock(&mm->unused_lock);
-	if (mm->num_unused < MM_UNUSED_TARGET) {
-		list_add(&node->node_list, &mm->unused_nodes);
-		++mm->num_unused;
-	} else
-		kfree(node);
-	spin_unlock(&mm->unused_lock);
-}
-EXPORT_SYMBOL(drm_mm_put_block);
-
-static int check_free_hole(unsigned long start, unsigned long end,
-			   unsigned long size, unsigned alignment)
+static int check_free_hole(u64 start, u64 end, u64 size, unsigned alignment)
 {
 	if (end - start < size)
 		return 0;
 
 	if (alignment) {
-		unsigned tmp = start % alignment;
-		if (tmp)
-			start += alignment - tmp;
+		u64 tmp = start;
+		unsigned rem;
+
+		rem = do_div(tmp, alignment);
+		if (rem)
+			start += alignment - rem;
 	}
 
 	return end >= start + size;
 }
 
-struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
-					       unsigned long size,
-					       unsigned alignment,
-					       unsigned long color,
-					       enum drm_mm_search_flags flags)
+static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
+						      u64 size,
+						      unsigned alignment,
+						      unsigned long color,
+						      enum drm_mm_search_flags flags)
 {
 	struct drm_mm_node *entry;
 	struct drm_mm_node *best;
-	unsigned long adj_start;
-	unsigned long adj_end;
-	unsigned long best_size;
+	u64 adj_start;
+	u64 adj_end;
+	u64 best_size;
 
 	BUG_ON(mm->scanned_blocks);
 
 	best = NULL;
 	best_size = ~0UL;
 
-	drm_mm_for_each_hole(entry, mm, adj_start, adj_end) {
+	__drm_mm_for_each_hole(entry, mm, adj_start, adj_end,
+			       flags & DRM_MM_SEARCH_BELOW) {
+		u64 hole_size = adj_end - adj_start;
+
 		if (mm->color_adjust) {
 			mm->color_adjust(entry, color, &adj_start, &adj_end);
 			if (adj_end <= adj_start)
@@ -427,36 +447,38 @@ struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
 		if (!(flags & DRM_MM_SEARCH_BEST))
 			return entry;
 
-		if (entry->size < best_size) {
+		if (hole_size < best_size) {
 			best = entry;
-			best_size = entry->size;
+			best_size = hole_size;
 		}
 	}
 
 	return best;
 }
-EXPORT_SYMBOL(drm_mm_search_free_generic);
 
-struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm,
-							unsigned long size,
+static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm,
+							u64 size,
 							unsigned alignment,
 							unsigned long color,
-							unsigned long start,
-							unsigned long end,
+							u64 start,
+							u64 end,
 							enum drm_mm_search_flags flags)
 {
 	struct drm_mm_node *entry;
 	struct drm_mm_node *best;
-	unsigned long adj_start;
-	unsigned long adj_end;
-	unsigned long best_size;
+	u64 adj_start;
+	u64 adj_end;
+	u64 best_size;
 
 	BUG_ON(mm->scanned_blocks);
 
 	best = NULL;
 	best_size = ~0UL;
 
-	drm_mm_for_each_hole(entry, mm, adj_start, adj_end) {
+	__drm_mm_for_each_hole(entry, mm, adj_start, adj_end,
+			       flags & DRM_MM_SEARCH_BELOW) {
+		u64 hole_size = adj_end - adj_start;
+
 		if (adj_start < start)
 			adj_start = start;
 		if (adj_end > end)
@@ -474,18 +496,23 @@ struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm,
 		if (!(flags & DRM_MM_SEARCH_BEST))
 			return entry;
 
-		if (entry->size < best_size) {
+		if (hole_size < best_size) {
 			best = entry;
-			best_size = entry->size;
+			best_size = hole_size;
 		}
 	}
 
 	return best;
 }
-EXPORT_SYMBOL(drm_mm_search_free_in_range_generic);
 
 /**
- * Moves an allocation. To be used with embedded struct drm_mm_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)
 {
@@ -503,16 +530,50 @@ void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
 EXPORT_SYMBOL(drm_mm_replace_node);
 
 /**
- * Initializa lru scanning.
+ * DOC: lru scan roaster
+ *
+ * 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 unecessarily.
+ *
+ * The DRM range allocator supports this use-case through the scanning
+ * interfaces. First a scan operation needs to be initialized with
+ * drm_mm_init_scan() or drm_mm_init_scan_with_range(). The the driver adds
+ * objects to the roaster (probably by walking an LRU list, but this can be
+ * freely implemented) until a suitable hole is found or there's no further
+ * evitable object.
+ *
+ * The 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 in the scan. 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 badly.
+ */
+
+/**
+ * drm_mm_init_scan - initialize lru scanning
+ * @mm: drm_mm to scan
+ * @size: size of the allocation
+ * @alignment: alignment of the allocation
+ * @color: opaque tag value to use for the allocation
  *
  * This simply sets up the scanning routines with the parameters for the desired
- * hole.
+ * hole. Note that there's no need to specify allocation flags, since they only
+ * change the place a node is allocated from within a suitable hole.
  *
- * Warning: As long as the scan list is non-empty, no other operations than
+ * 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_init_scan(struct drm_mm *mm,
-		      unsigned long size,
+		      u64 size,
 		      unsigned alignment,
 		      unsigned long color)
 {
@@ -528,20 +589,28 @@ void drm_mm_init_scan(struct drm_mm *mm,
 EXPORT_SYMBOL(drm_mm_init_scan);
 
 /**
- * Initializa lru scanning.
+ * drm_mm_init_scan - initialize range-restricted lru scanning
+ * @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
  *
  * This simply sets up the scanning routines with the parameters for the desired
- * hole. This version is for range-restricted scans.
+ * hole. Note that there's no need to specify allocation flags, since they only
+ * change the place a node is allocated from within a suitable hole.
  *
- * Warning: As long as the scan list is non-empty, no other operations than
+ * 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_init_scan_with_range(struct drm_mm *mm,
-				 unsigned long size,
+				 u64 size,
 				 unsigned alignment,
 				 unsigned long color,
-				 unsigned long start,
-				 unsigned long end)
+				 u64 start,
+				 u64 end)
 {
 	mm->scan_color = color;
 	mm->scan_alignment = alignment;
@@ -557,17 +626,21 @@ void drm_mm_init_scan_with_range(struct drm_mm *mm,
 EXPORT_SYMBOL(drm_mm_init_scan_with_range);
 
 /**
+ * drm_mm_scan_add_block - add a node to the scan list
+ * @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 non-zero, if a hole has been found, zero otherwise.
+ * Returns:
+ * True if a hole has been found, false otherwise.
  */
-int drm_mm_scan_add_block(struct drm_mm_node *node)
+bool drm_mm_scan_add_block(struct drm_mm_node *node)
 {
 	struct drm_mm *mm = node->mm;
 	struct drm_mm_node *prev_node;
-	unsigned long hole_start, hole_end;
-	unsigned long adj_start, adj_end;
+	u64 hole_start, hole_end;
+	u64 adj_start, adj_end;
 
 	mm->scanned_blocks++;
 
@@ -602,15 +675,16 @@ int drm_mm_scan_add_block(struct drm_mm_node *node)
 			    mm->scan_size, mm->scan_alignment)) {
 		mm->scan_hit_start = hole_start;
 		mm->scan_hit_end = hole_end;
-		return 1;
+		return true;
 	}
 
-	return 0;
+	return false;
 }
 EXPORT_SYMBOL(drm_mm_scan_add_block);
 
 /**
- * Remove a node from the scan list.
+ * drm_mm_scan_remove_block - remove a node from the scan list
+ * @node: drm_mm_node to remove
  *
  * Nodes _must_ be removed in the exact same order from the scan list as they
  * have been added, otherwise the internal state of the memory manager will be
@@ -620,10 +694,11 @@ EXPORT_SYMBOL(drm_mm_scan_add_block);
  * immediately following drm_mm_search_free with !DRM_MM_SEARCH_BEST will then
  * return the just freed block (because its at the top of the free_stack list).
  *
- * Returns one if this block should be evicted, zero otherwise. Will always
- * return zero when no hole has been found.
+ * Returns:
+ * True if this block should be evicted, false otherwise. Will always
+ * return false when no hole has been found.
  */
-int drm_mm_scan_remove_block(struct drm_mm_node *node)
+bool drm_mm_scan_remove_block(struct drm_mm_node *node)
 {
 	struct drm_mm *mm = node->mm;
 	struct drm_mm_node *prev_node;
@@ -644,7 +719,15 @@ int drm_mm_scan_remove_block(struct drm_mm_node *node)
 }
 EXPORT_SYMBOL(drm_mm_scan_remove_block);
 
-int drm_mm_clean(struct drm_mm * mm)
+/**
+ * drm_mm_clean - checks whether an allocator is clean
+ * @mm: drm_mm allocator to check
+ *
+ * Returns:
+ * True if the allocator is completely free, false if there's still a node
+ * allocated in it.
+ */
+bool drm_mm_clean(struct drm_mm * mm)
 {
 	struct list_head *head = &mm->head_node.node_list;
 
@@ -652,13 +735,18 @@ int drm_mm_clean(struct drm_mm * mm)
 }
 EXPORT_SYMBOL(drm_mm_clean);
 
-void drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
+/**
+ * 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)
 {
 	INIT_LIST_HEAD(&mm->hole_stack);
-	INIT_LIST_HEAD(&mm->unused_nodes);
-	mm->num_unused = 0;
 	mm->scanned_blocks = 0;
-	mtx_init(&mm->unused_lock, IPL_NONE);
 
 	/* Clever trick to avoid a special case in the free hole tracking. */
 	INIT_LIST_HEAD(&mm->head_node.node_list);
@@ -676,100 +764,101 @@ void drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
 }
 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)
 {
-	struct drm_mm_node *entry, *next;
-
-	if (WARN(!list_empty(&mm->head_node.node_list),
-		 "Memory manager not clean. Delaying takedown\n")) {
-		return;
-	}
-
-	spin_lock(&mm->unused_lock);
-	list_for_each_entry_safe(entry, next, &mm->unused_nodes, node_list) {
-		list_del(&entry->node_list);
-		kfree(entry);
-		--mm->num_unused;
-	}
-	spin_unlock(&mm->unused_lock);
-
-	BUG_ON(mm->num_unused != 0);
+	WARN(!list_empty(&mm->head_node.node_list),
+	     "Memory manager not clean during takedown.\n");
 }
 EXPORT_SYMBOL(drm_mm_takedown);
 
-static unsigned long drm_mm_debug_hole(struct drm_mm_node *entry,
-				       const char *prefix)
+static u64 drm_mm_debug_hole(struct drm_mm_node *entry,
+				     const char *prefix)
 {
-	unsigned long hole_start, hole_end, hole_size;
+	u64 hole_start, hole_end, hole_size;
 
 	if (entry->hole_follows) {
 		hole_start = drm_mm_hole_node_start(entry);
 		hole_end = drm_mm_hole_node_end(entry);
 		hole_size = hole_end - hole_start;
-		printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: free\n",
-			prefix, hole_start, hole_end,
-			hole_size);
+		pr_debug("%s %#llx-%#llx: %llu: free\n", prefix, hole_start,
+			 hole_end, hole_size);
 		return hole_size;
 	}
 
 	return 0;
 }
 
+/**
+ * drm_mm_debug_table - dump allocator state to dmesg
+ * @mm: drm_mm allocator to dump
+ * @prefix: prefix to use for dumping to dmesg
+ */
 void drm_mm_debug_table(struct drm_mm *mm, const char *prefix)
 {
 	struct drm_mm_node *entry;
-	unsigned long total_used = 0, total_free = 0, total = 0;
+	u64 total_used = 0, total_free = 0, total = 0;
 
 	total_free += drm_mm_debug_hole(&mm->head_node, prefix);
 
 	drm_mm_for_each_node(entry, mm) {
-		printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8lu: used\n",
-			prefix, entry->start, entry->start + entry->size,
-			entry->size);
+		pr_debug("%s %#llx-%#llx: %llu: used\n", prefix, entry->start,
+			 entry->start + entry->size, entry->size);
 		total_used += entry->size;
 		total_free += drm_mm_debug_hole(entry, prefix);
 	}
 	total = total_free + total_used;
 
-	printk(KERN_DEBUG "%s total: %lu, used %lu free %lu\n", prefix, total,
-		total_used, total_free);
+	pr_debug("%s total: %llu, used %llu free %llu\n", prefix, total,
+		 total_used, total_free);
 }
 EXPORT_SYMBOL(drm_mm_debug_table);
 
 #if defined(CONFIG_DEBUG_FS)
-static unsigned long drm_mm_dump_hole(struct seq_file *m, struct drm_mm_node *entry)
+static u64 drm_mm_dump_hole(struct seq_file *m, struct drm_mm_node *entry)
 {
-	unsigned long hole_start, hole_end, hole_size;
+	u64 hole_start, hole_end, hole_size;
 
 	if (entry->hole_follows) {
 		hole_start = drm_mm_hole_node_start(entry);
 		hole_end = drm_mm_hole_node_end(entry);
 		hole_size = hole_end - hole_start;
-		seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: free\n",
-				hole_start, hole_end, hole_size);
+		seq_printf(m, "%#018llx-%#018llx: %llu: free\n", hole_start,
+			   hole_end, hole_size);
 		return hole_size;
 	}
 
 	return 0;
 }
 
+/**
+ * drm_mm_dump_table - dump allocator state to a seq_file
+ * @m: seq_file to dump to
+ * @mm: drm_mm allocator to dump
+ */
 int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
 {
 	struct drm_mm_node *entry;
-	unsigned long total_used = 0, total_free = 0, total = 0;
+	u64 total_used = 0, total_free = 0, total = 0;
 
 	total_free += drm_mm_dump_hole(m, &mm->head_node);
 
 	drm_mm_for_each_node(entry, mm) {
-		seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: used\n",
-				entry->start, entry->start + entry->size,
-				entry->size);
+		seq_printf(m, "%#018llx-%#018llx: %llu: used\n", entry->start,
+			   entry->start + entry->size, entry->size);
 		total_used += entry->size;
 		total_free += drm_mm_dump_hole(m, entry);
 	}
 	total = total_free + total_used;
 
-	seq_printf(m, "total: %lu, used %lu free %lu\n", total, total_used, total_free);
+	seq_printf(m, "total: %llu, used %llu free %llu\n", total,
+		   total_used, total_free);
 	return 0;
 }
 EXPORT_SYMBOL(drm_mm_dump_table);