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Diffstat (limited to 'drivers/gpu/drm/drm_mm.c')
| -rw-r--r-- | drivers/gpu/drm/drm_mm.c | 1041 |
1 files changed, 1041 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c new file mode 100644 index 000000000..8257f9d4f --- /dev/null +++ b/drivers/gpu/drm/drm_mm.c @@ -0,0 +1,1041 @@ +/************************************************************************** + * + * 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); |