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- /**************************************************************************
- *
- * 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 <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;
- 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 [%08llx + %08llx]: unknown owner\n",
- node->start, node->size);
- continue;
- }
- stack_depot_snprint(node->stack, buf, BUFSZ, 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 (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);
- }
- #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);
- }
- RB_DECLARE_CALLBACKS_MAX(static, augment_callbacks,
- struct drm_mm_node, rb_hole_addr,
- u64, subtree_max_hole, HOLE_SIZE)
- static void insert_hole_addr(struct rb_root *root, struct drm_mm_node *node)
- {
- struct rb_node **link = &root->rb_node, *rb_parent = NULL;
- u64 start = HOLE_ADDR(node), subtree_max_hole = node->subtree_max_hole;
- struct drm_mm_node *parent;
- while (*link) {
- rb_parent = *link;
- parent = rb_entry(rb_parent, struct drm_mm_node, rb_hole_addr);
- if (parent->subtree_max_hole < subtree_max_hole)
- parent->subtree_max_hole = subtree_max_hole;
- if (start < HOLE_ADDR(parent))
- link = &parent->rb_hole_addr.rb_left;
- else
- link = &parent->rb_hole_addr.rb_right;
- }
- rb_link_node(&node->rb_hole_addr, rb_parent, link);
- rb_insert_augmented(&node->rb_hole_addr, root, &augment_callbacks);
- }
- 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);
- node->subtree_max_hole = node->hole_size;
- DRM_MM_BUG_ON(!drm_mm_hole_follows(node));
- insert_hole_size(&mm->holes_size, node);
- insert_hole_addr(&mm->holes_addr, node);
- 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_augmented(&node->rb_hole_addr, &node->mm->holes_addr,
- &augment_callbacks);
- node->hole_size = 0;
- node->subtree_max_hole = 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 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 bool usable_hole_addr(struct rb_node *rb, u64 size)
- {
- return rb && rb_hole_addr_to_node(rb)->subtree_max_hole >= size;
- }
- static struct drm_mm_node *find_hole_addr(struct drm_mm *mm, u64 addr, u64 size)
- {
- struct rb_node *rb = mm->holes_addr.rb_node;
- struct drm_mm_node *node = NULL;
- while (rb) {
- u64 hole_start;
- if (!usable_hole_addr(rb, size))
- break;
- 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_addr(mm, start, size);
- case DRM_MM_INSERT_HIGH:
- return find_hole_addr(mm, end, size);
- case DRM_MM_INSERT_EVICT:
- return list_first_entry_or_null(&mm->hole_stack,
- struct drm_mm_node,
- hole_stack);
- }
- }
- /**
- * DECLARE_NEXT_HOLE_ADDR - macro to declare next hole functions
- * @name: name of function to declare
- * @first: first rb member to traverse (either rb_left or rb_right).
- * @last: last rb member to traverse (either rb_right or rb_left).
- *
- * This macro declares a function to return the next hole of the addr rb tree.
- * While traversing the tree we take the searched size into account and only
- * visit branches with potential big enough holes.
- */
- #define DECLARE_NEXT_HOLE_ADDR(name, first, last) \
- static struct drm_mm_node *name(struct drm_mm_node *entry, u64 size) \
- { \
- struct rb_node *parent, *node = &entry->rb_hole_addr; \
- \
- if (!entry || RB_EMPTY_NODE(node)) \
- return NULL; \
- \
- if (usable_hole_addr(node->first, size)) { \
- node = node->first; \
- while (usable_hole_addr(node->last, size)) \
- node = node->last; \
- return rb_hole_addr_to_node(node); \
- } \
- \
- while ((parent = rb_parent(node)) && node == parent->first) \
- node = parent; \
- \
- return rb_hole_addr_to_node(parent); \
- }
- DECLARE_NEXT_HOLE_ADDR(next_hole_high_addr, rb_left, rb_right)
- DECLARE_NEXT_HOLE_ADDR(next_hole_low_addr, rb_right, rb_left)
- static struct drm_mm_node *
- next_hole(struct drm_mm *mm,
- struct drm_mm_node *node,
- u64 size,
- 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 next_hole_low_addr(node, size);
- case DRM_MM_INSERT_HIGH:
- return next_hole_high_addr(node, size);
- 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)
- {
- struct drm_mm_node *hole;
- u64 hole_start, hole_end;
- u64 adj_start, adj_end;
- u64 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_addr(mm, node->start, 0);
- 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);
- drm_mm_interval_tree_add_node(hole, node);
- 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, size, 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);
- drm_mm_interval_tree_add_node(hole, node);
- 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);
- drm_mm_interval_tree_remove(node, &mm->interval_tree);
- 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);
- 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);
- }
- 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 candidates 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);
- 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.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;
- #ifdef CONFIG_DRM_DEBUG_MM
- stack_depot_init();
- #endif
- }
- 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);
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