v4.19.13 snapshot.
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
new file mode 100644
index 0000000..3cc5fbd
--- /dev/null
+++ b/drivers/gpu/drm/drm_mm.c
@@ -0,0 +1,991 @@
+/**************************************************************************
+ *
+ * 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 <drm/drmP.h>
+#include <drm/drm_mm.h>
+#include <linux/slab.h>
+#include <linux/seq_file.h>
+#include <linux/export.h>
+#include <linux/interval_tree_generic.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];
+ struct stack_trace trace = {
+ .entries = entries,
+ .max_entries = STACKDEPTH,
+ .skip = 1
+ };
+
+ save_stack_trace(&trace);
+ if (trace.nr_entries != 0 &&
+ trace.entries[trace.nr_entries-1] == ULONG_MAX)
+ trace.nr_entries--;
+
+ /* May be called under spinlock, so avoid sleeping */
+ node->stack = depot_save_stack(&trace, GFP_NOWAIT);
+}
+
+static void show_leaks(struct drm_mm *mm)
+{
+ struct drm_mm_node *node;
+ unsigned long entries[STACKDEPTH];
+ char *buf;
+
+ buf = kmalloc(BUFSZ, GFP_KERNEL);
+ if (!buf)
+ return;
+
+ list_for_each_entry(node, drm_mm_nodes(mm), node_list) {
+ struct stack_trace trace = {
+ .entries = entries,
+ .max_entries = STACKDEPTH
+ };
+
+ if (!node->stack) {
+ DRM_ERROR("node [%08llx + %08llx]: unknown owner\n",
+ node->start, node->size);
+ continue;
+ }
+
+ depot_fetch_stack(node->stack, &trace);
+ snprint_stack_trace(buf, BUFSZ, &trace, 0);
+ DRM_ERROR("node [%08llx + %08llx]: 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)
+
+INTERVAL_TREE_DEFINE(struct drm_mm_node, rb,
+ u64, __subtree_last,
+ START, LAST, static inline, drm_mm_interval_tree)
+
+struct drm_mm_node *
+__drm_mm_interval_first(const struct drm_mm *mm, u64 start, u64 last)
+{
+ return drm_mm_interval_tree_iter_first((struct rb_root_cached *)&mm->interval_tree,
+ start, last) ?: (struct drm_mm_node *)&mm->head_node;
+}
+EXPORT_SYMBOL(__drm_mm_interval_first);
+
+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 (hole_node->allocated) {
+ 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);
+}
+
+#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)
+
+#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 void insert_hole_size(struct rb_root_cached *root,
+ struct drm_mm_node *node)
+{
+ 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);
+}
+
+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);
+ RB_INSERT(mm->holes_addr, rb_hole_addr, HOLE_ADDR);
+
+ 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)
+{
+ 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;
+}
+
+static struct drm_mm_node *find_hole(struct drm_mm *mm, u64 addr)
+{
+ 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;
+}
+
+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:
+ return rb_hole_size_to_node(rb_prev(&node->rb_hole_size));
+
+ case DRM_MM_INSERT_LOW:
+ return rb_hole_addr_to_node(rb_next(&node->rb_hole_addr));
+
+ case DRM_MM_INSERT_HIGH:
+ return rb_hole_addr_to_node(rb_prev(&node->rb_hole_addr));
+
+ 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;
+
+ list_add(&node->node_list, &hole->node_list);
+ drm_mm_interval_tree_add_node(hole, node);
+ node->allocated = true;
+ 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;
+
+ list_add(&node->node_list, &hole->node_list);
+ drm_mm_interval_tree_add_node(hole, node);
+ node->allocated = true;
+
+ 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);
+
+/**
+ * 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(!node->allocated);
+ DRM_MM_BUG_ON(node->scanned_block);
+
+ prev_node = list_prev_entry(node, node_list);
+
+ if (drm_mm_hole_follows(node))
+ rm_hole(node);
+
+ drm_mm_interval_tree_remove(node, &mm->interval_tree);
+ list_del(&node->node_list);
+ node->allocated = false;
+
+ if (drm_mm_hole_follows(prev_node))
+ rm_hole(prev_node);
+ add_hole(prev_node);
+}
+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(!old->allocated);
+
+ *new = *old;
+
+ list_replace(&old->node_list, &new->node_list);
+ rb_replace_node_cached(&old->rb, &new->rb, &mm->interval_tree);
+
+ 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);
+ }
+
+ old->allocated = false;
+ new->allocated = true;
+}
+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(!node->allocated);
+ DRM_MM_BUG_ON(node->scanned_block);
+ node->scanned_block = true;
+ 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 its 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(!node->scanned_block);
+ node->scanned_block = false;
+
+ 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);
+ mm->interval_tree = RB_ROOT_CACHED;
+ mm->holes_size = RB_ROOT_CACHED;
+ mm->holes_addr = RB_ROOT;
+
+ /* Clever trick to avoid a special case in the free hole tracking. */
+ INIT_LIST_HEAD(&mm->head_node.node_list);
+ mm->head_node.allocated = false;
+ 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, "%#018llx-%#018llx: %llu: 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, "%#018llx-%#018llx: %llu: 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: %llu, used %llu free %llu\n", total,
+ total_used, total_free);
+}
+EXPORT_SYMBOL(drm_mm_print);