| /************************************************************************** |
| * |
| * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND., USA. |
| * 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 allocations of its own, so if |
| * drivers choose not to embed nodes they need to still allocate them |
| * themselves. |
| * |
| * The range allocator also supports reservation of preallocated blocks. This is |
| * useful for taking over initial mode setting configurations from the firmware, |
| * where an object needs to be created which exactly matches the firmware's |
| * scanout target. As long as the range is still free it can be inserted anytime |
| * after the allocator is initialized, which helps with avoiding looped |
| * depencies in the driver load sequence. |
| * |
| * drm_mm maintains a stack of most recently freed holes, which of all |
| * simplistic datastructures seems to be a fairly decent approach to clustering |
| * allocations and avoiding too much fragmentation. This means free space |
| * searches are O(num_holes). Given that all the fancy features drm_mm supports |
| * something better would be fairly complex and since gfx thrashing is a fairly |
| * steep cliff not a real concern. Removing a node again is O(1). |
| * |
| * drm_mm supports a few features: Alignment and range restrictions can be |
| * supplied. Further more every &drm_mm_node has a color value (which is just an |
| * opaqua unsigned long) which in conjunction with a driver callback can be used |
| * to implement sophisticated placement restrictions. The i915 DRM driver uses |
| * this to implement guard pages between incompatible caching domains in the |
| * graphics TT. |
| * |
| * 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. |
| */ |
| |
| static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm, |
| u64 size, |
| unsigned alignment, |
| unsigned long color, |
| enum drm_mm_search_flags flags); |
| static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm, |
| u64 size, |
| unsigned alignment, |
| unsigned long color, |
| u64 start, |
| u64 end, |
| enum drm_mm_search_flags flags); |
| |
| #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, &mm->head_node.node_list, 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(struct drm_mm *mm, u64 start, u64 last) |
| { |
| return drm_mm_interval_tree_iter_first(&mm->interval_tree, |
| start, last); |
| } |
| 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; |
| |
| 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; |
| } else { |
| rb = NULL; |
| link = &mm->interval_tree.rb_node; |
| } |
| |
| 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; |
| } |
| |
| rb_link_node(&node->rb, rb, link); |
| rb_insert_augmented(&node->rb, |
| &mm->interval_tree, |
| &drm_mm_interval_tree_augment); |
| } |
| |
| static void drm_mm_insert_helper(struct drm_mm_node *hole_node, |
| struct drm_mm_node *node, |
| u64 size, unsigned alignment, |
| unsigned long color, |
| enum drm_mm_allocator_flags flags) |
| { |
| struct drm_mm *mm = hole_node->mm; |
| u64 hole_start = drm_mm_hole_node_start(hole_node); |
| u64 hole_end = drm_mm_hole_node_end(hole_node); |
| u64 adj_start = hole_start; |
| u64 adj_end = hole_end; |
| |
| BUG_ON(node->allocated); |
| |
| if (mm->color_adjust) |
| mm->color_adjust(hole_node, color, &adj_start, &adj_end); |
| |
| if (flags & DRM_MM_CREATE_TOP) |
| adj_start = adj_end - size; |
| |
| if (alignment) { |
| u64 tmp = adj_start; |
| unsigned rem; |
| |
| rem = do_div(tmp, alignment); |
| if (rem) { |
| if (flags & DRM_MM_CREATE_TOP) |
| adj_start -= rem; |
| else |
| adj_start += alignment - rem; |
| } |
| } |
| |
| BUG_ON(adj_start < hole_start); |
| BUG_ON(adj_end > hole_end); |
| |
| if (adj_start == hole_start) { |
| hole_node->hole_follows = 0; |
| list_del(&hole_node->hole_stack); |
| } |
| |
| node->start = adj_start; |
| node->size = size; |
| node->mm = mm; |
| node->color = color; |
| node->allocated = 1; |
| |
| list_add(&node->node_list, &hole_node->node_list); |
| |
| drm_mm_interval_tree_add_node(hole_node, node); |
| |
| BUG_ON(node->start + node->size > adj_end); |
| |
| node->hole_follows = 0; |
| if (__drm_mm_hole_node_start(node) < hole_end) { |
| list_add(&node->hole_stack, &mm->hole_stack); |
| node->hole_follows = 1; |
| } |
| |
| save_stack(node); |
| } |
| |
| /** |
| * drm_mm_reserve_node - insert an pre-initialized node |
| * @mm: drm_mm allocator to insert @node into |
| * @node: drm_mm_node to insert |
| * |
| * This functions inserts an already set-up drm_mm_node into the allocator, |
| * meaning that start, size and color must be set by the caller. This is useful |
| * to initialize the allocator with preallocated objects which must be set-up |
| * before the range allocator can be set-up, e.g. when taking over a firmware |
| * framebuffer. |
| * |
| * Returns: |
| * 0 on success, -ENOSPC if there's no hole where @node is. |
| */ |
| int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node) |
| { |
| u64 end = node->start + node->size; |
| struct drm_mm_node *hole; |
| u64 hole_start, hole_end; |
| |
| if (WARN_ON(node->size == 0)) |
| return -EINVAL; |
| |
| end = node->start + node->size; |
| |
| /* Find the relevant hole to add our node to */ |
| hole = drm_mm_interval_tree_iter_first(&mm->interval_tree, |
| node->start, ~(u64)0); |
| if (hole) { |
| if (hole->start < end) |
| return -ENOSPC; |
| } else { |
| hole = list_entry(&mm->head_node.node_list, |
| typeof(*hole), node_list); |
| } |
| |
| hole = list_last_entry(&hole->node_list, typeof(*hole), node_list); |
| if (!hole->hole_follows) |
| return -ENOSPC; |
| |
| hole_start = __drm_mm_hole_node_start(hole); |
| hole_end = __drm_mm_hole_node_end(hole); |
| if (hole_start > node->start || hole_end < end) |
| return -ENOSPC; |
| |
| node->mm = mm; |
| node->allocated = 1; |
| |
| list_add(&node->node_list, &hole->node_list); |
| |
| drm_mm_interval_tree_add_node(hole, node); |
| |
| if (node->start == hole_start) { |
| hole->hole_follows = 0; |
| list_del(&hole->hole_stack); |
| } |
| |
| node->hole_follows = 0; |
| if (end != hole_end) { |
| list_add(&node->hole_stack, &mm->hole_stack); |
| node->hole_follows = 1; |
| } |
| |
| save_stack(node); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(drm_mm_reserve_node); |
| |
| /** |
| * drm_mm_insert_node_generic - search for space and insert @node |
| * @mm: drm_mm to allocate from |
| * @node: preallocate node to insert |
| * @size: size of the allocation |
| * @alignment: alignment of the allocation |
| * @color: opaque tag value to use for this node |
| * @sflags: flags to fine-tune the allocation search |
| * @aflags: flags to fine-tune the allocation behavior |
| * |
| * The preallocated node must be cleared to 0. |
| * |
| * Returns: |
| * 0 on success, -ENOSPC if there's no suitable hole. |
| */ |
| int drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node, |
| u64 size, unsigned alignment, |
| unsigned long color, |
| enum drm_mm_search_flags sflags, |
| enum drm_mm_allocator_flags aflags) |
| { |
| struct drm_mm_node *hole_node; |
| |
| if (WARN_ON(size == 0)) |
| return -EINVAL; |
| |
| hole_node = drm_mm_search_free_generic(mm, size, alignment, |
| color, sflags); |
| if (!hole_node) |
| return -ENOSPC; |
| |
| drm_mm_insert_helper(hole_node, node, size, alignment, color, aflags); |
| return 0; |
| } |
| EXPORT_SYMBOL(drm_mm_insert_node_generic); |
| |
| static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node, |
| struct drm_mm_node *node, |
| u64 size, unsigned alignment, |
| unsigned long color, |
| u64 start, u64 end, |
| enum drm_mm_allocator_flags flags) |
| { |
| struct drm_mm *mm = hole_node->mm; |
| u64 hole_start = drm_mm_hole_node_start(hole_node); |
| u64 hole_end = drm_mm_hole_node_end(hole_node); |
| u64 adj_start = hole_start; |
| u64 adj_end = hole_end; |
| |
| BUG_ON(!hole_node->hole_follows || node->allocated); |
| |
| if (adj_start < start) |
| adj_start = start; |
| if (adj_end > end) |
| adj_end = end; |
| |
| if (mm->color_adjust) |
| mm->color_adjust(hole_node, color, &adj_start, &adj_end); |
| |
| if (flags & DRM_MM_CREATE_TOP) |
| adj_start = adj_end - size; |
| |
| if (alignment) { |
| u64 tmp = adj_start; |
| unsigned rem; |
| |
| rem = do_div(tmp, alignment); |
| if (rem) { |
| if (flags & DRM_MM_CREATE_TOP) |
| adj_start -= rem; |
| else |
| adj_start += alignment - rem; |
| } |
| } |
| |
| if (adj_start == hole_start) { |
| hole_node->hole_follows = 0; |
| list_del(&hole_node->hole_stack); |
| } |
| |
| node->start = adj_start; |
| node->size = size; |
| node->mm = mm; |
| node->color = color; |
| node->allocated = 1; |
| |
| list_add(&node->node_list, &hole_node->node_list); |
| |
| drm_mm_interval_tree_add_node(hole_node, node); |
| |
| BUG_ON(node->start < start); |
| BUG_ON(node->start < adj_start); |
| BUG_ON(node->start + node->size > adj_end); |
| BUG_ON(node->start + node->size > end); |
| |
| node->hole_follows = 0; |
| if (__drm_mm_hole_node_start(node) < hole_end) { |
| list_add(&node->hole_stack, &mm->hole_stack); |
| node->hole_follows = 1; |
| } |
| |
| save_stack(node); |
| } |
| |
| /** |
| * drm_mm_insert_node_in_range_generic - ranged search for space and insert @node |
| * @mm: drm_mm to allocate from |
| * @node: preallocate node to insert |
| * @size: size of the allocation |
| * @alignment: alignment of the allocation |
| * @color: opaque tag value to use for this node |
| * @start: start of the allowed range for this node |
| * @end: end of the allowed range for this node |
| * @sflags: flags to fine-tune the allocation search |
| * @aflags: flags to fine-tune the allocation behavior |
| * |
| * The preallocated node must be cleared to 0. |
| * |
| * Returns: |
| * 0 on success, -ENOSPC if there's no suitable hole. |
| */ |
| int drm_mm_insert_node_in_range_generic(struct drm_mm *mm, struct drm_mm_node *node, |
| u64 size, unsigned alignment, |
| unsigned long color, |
| u64 start, u64 end, |
| enum drm_mm_search_flags sflags, |
| enum drm_mm_allocator_flags aflags) |
| { |
| struct drm_mm_node *hole_node; |
| |
| if (WARN_ON(size == 0)) |
| return -EINVAL; |
| |
| hole_node = drm_mm_search_free_in_range_generic(mm, |
| size, alignment, color, |
| start, end, sflags); |
| if (!hole_node) |
| return -ENOSPC; |
| |
| drm_mm_insert_helper_range(hole_node, node, |
| size, alignment, color, |
| start, end, aflags); |
| return 0; |
| } |
| EXPORT_SYMBOL(drm_mm_insert_node_in_range_generic); |
| |
| /** |
| * drm_mm_remove_node - Remove a memory node from the allocator. |
| * @node: drm_mm_node to remove |
| * |
| * This just removes a node from its drm_mm allocator. The node does not need to |
| * be cleared again before it can be re-inserted into this or any other drm_mm |
| * allocator. It is a bug to call this function on a un-allocated node. |
| */ |
| void drm_mm_remove_node(struct drm_mm_node *node) |
| { |
| struct drm_mm *mm = node->mm; |
| struct drm_mm_node *prev_node; |
| |
| if (WARN_ON(!node->allocated)) |
| return; |
| |
| BUG_ON(node->scanned_block || node->scanned_prev_free |
| || node->scanned_next_free); |
| |
| prev_node = |
| list_entry(node->node_list.prev, struct drm_mm_node, node_list); |
| |
| if (node->hole_follows) { |
| BUG_ON(__drm_mm_hole_node_start(node) == |
| __drm_mm_hole_node_end(node)); |
| list_del(&node->hole_stack); |
| } else |
| BUG_ON(__drm_mm_hole_node_start(node) != |
| __drm_mm_hole_node_end(node)); |
| |
| |
| if (!prev_node->hole_follows) { |
| prev_node->hole_follows = 1; |
| list_add(&prev_node->hole_stack, &mm->hole_stack); |
| } else |
| list_move(&prev_node->hole_stack, &mm->hole_stack); |
| |
| drm_mm_interval_tree_remove(node, &mm->interval_tree); |
| list_del(&node->node_list); |
| node->allocated = 0; |
| } |
| EXPORT_SYMBOL(drm_mm_remove_node); |
| |
| static int check_free_hole(u64 start, u64 end, u64 size, unsigned alignment) |
| { |
| if (end - start < size) |
| return 0; |
| |
| if (alignment) { |
| u64 tmp = start; |
| unsigned rem; |
| |
| rem = do_div(tmp, alignment); |
| if (rem) |
| start += alignment - rem; |
| } |
| |
| return end >= start + size; |
| } |
| |
| static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm, |
| u64 size, |
| unsigned alignment, |
| unsigned long color, |
| enum drm_mm_search_flags flags) |
| { |
| struct drm_mm_node *entry; |
| struct drm_mm_node *best; |
| u64 adj_start; |
| u64 adj_end; |
| u64 best_size; |
| |
| BUG_ON(mm->scanned_blocks); |
| |
| best = NULL; |
| best_size = ~0UL; |
| |
| __drm_mm_for_each_hole(entry, mm, adj_start, adj_end, |
| flags & DRM_MM_SEARCH_BELOW) { |
| u64 hole_size = adj_end - adj_start; |
| |
| if (mm->color_adjust) { |
| mm->color_adjust(entry, color, &adj_start, &adj_end); |
| if (adj_end <= adj_start) |
| continue; |
| } |
| |
| if (!check_free_hole(adj_start, adj_end, size, alignment)) |
| continue; |
| |
| if (!(flags & DRM_MM_SEARCH_BEST)) |
| return entry; |
| |
| if (hole_size < best_size) { |
| best = entry; |
| best_size = hole_size; |
| } |
| } |
| |
| return best; |
| } |
| |
| static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm, |
| u64 size, |
| unsigned alignment, |
| unsigned long color, |
| u64 start, |
| u64 end, |
| enum drm_mm_search_flags flags) |
| { |
| struct drm_mm_node *entry; |
| struct drm_mm_node *best; |
| u64 adj_start; |
| u64 adj_end; |
| u64 best_size; |
| |
| BUG_ON(mm->scanned_blocks); |
| |
| best = NULL; |
| best_size = ~0UL; |
| |
| __drm_mm_for_each_hole(entry, mm, adj_start, adj_end, |
| flags & DRM_MM_SEARCH_BELOW) { |
| u64 hole_size = adj_end - adj_start; |
| |
| if (adj_start < start) |
| adj_start = start; |
| if (adj_end > end) |
| adj_end = end; |
| |
| if (mm->color_adjust) { |
| mm->color_adjust(entry, color, &adj_start, &adj_end); |
| if (adj_end <= adj_start) |
| continue; |
| } |
| |
| if (!check_free_hole(adj_start, adj_end, size, alignment)) |
| continue; |
| |
| if (!(flags & DRM_MM_SEARCH_BEST)) |
| return entry; |
| |
| if (hole_size < best_size) { |
| best = entry; |
| best_size = hole_size; |
| } |
| } |
| |
| return best; |
| } |
| |
| /** |
| * 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) |
| { |
| list_replace(&old->node_list, &new->node_list); |
| list_replace(&old->hole_stack, &new->hole_stack); |
| rb_replace_node(&old->rb, &new->rb, &old->mm->interval_tree); |
| new->hole_follows = old->hole_follows; |
| new->mm = old->mm; |
| new->start = old->start; |
| new->size = old->size; |
| new->color = old->color; |
| new->__subtree_last = old->__subtree_last; |
| |
| old->allocated = 0; |
| new->allocated = 1; |
| } |
| EXPORT_SYMBOL(drm_mm_replace_node); |
| |
| /** |
| * DOC: lru scan roaster |
| * |
| * Very often GPUs need to have continuous allocations for a given object. When |
| * evicting objects to make space for a new one it is therefore not most |
| * efficient when we simply start to select all objects from the tail of an LRU |
| * until there's a suitable hole: Especially for big objects or nodes that |
| * otherwise have special allocation constraints there's a good chance we evict |
| * lots of (smaller) objects unecessarily. |
| * |
| * The DRM range allocator supports this use-case through the scanning |
| * interfaces. First a scan operation needs to be initialized with |
| * drm_mm_init_scan() or drm_mm_init_scan_with_range(). The the driver adds |
| * objects to the roaster (probably by walking an LRU list, but this can be |
| * freely implemented) until a suitable hole is found or there's no further |
| * evitable object. |
| * |
| * The the driver must walk through all objects again in exactly the reverse |
| * order to restore the allocator state. Note that while the allocator is used |
| * in the scan mode no other operation is allowed. |
| * |
| * Finally the driver evicts all objects selected in the scan. Adding and |
| * removing an object is O(1), and since freeing a node is also O(1) the overall |
| * complexity is O(scanned_objects). So like the free stack which needs to be |
| * walked before a scan operation even begins this is linear in the number of |
| * objects. It doesn't seem to hurt badly. |
| */ |
| |
| /** |
| * drm_mm_init_scan - initialize lru scanning |
| * @mm: drm_mm to scan |
| * @size: size of the allocation |
| * @alignment: alignment of the allocation |
| * @color: opaque tag value to use for the allocation |
| * |
| * This simply sets up the scanning routines with the parameters for the desired |
| * hole. Note that there's no need to specify allocation flags, since they only |
| * change the place a node is allocated from within a suitable hole. |
| * |
| * Warning: |
| * As long as the scan list is non-empty, no other operations than |
| * adding/removing nodes to/from the scan list are allowed. |
| */ |
| void drm_mm_init_scan(struct drm_mm *mm, |
| u64 size, |
| unsigned alignment, |
| unsigned long color) |
| { |
| mm->scan_color = color; |
| mm->scan_alignment = alignment; |
| mm->scan_size = size; |
| mm->scanned_blocks = 0; |
| mm->scan_hit_start = 0; |
| mm->scan_hit_end = 0; |
| mm->scan_check_range = 0; |
| mm->prev_scanned_node = NULL; |
| } |
| EXPORT_SYMBOL(drm_mm_init_scan); |
| |
| /** |
| * drm_mm_init_scan - initialize range-restricted lru scanning |
| * @mm: drm_mm to scan |
| * @size: size of the allocation |
| * @alignment: alignment of the allocation |
| * @color: opaque tag value to use for the allocation |
| * @start: start of the allowed range for the allocation |
| * @end: end of the allowed range for the allocation |
| * |
| * This simply sets up the scanning routines with the parameters for the desired |
| * hole. Note that there's no need to specify allocation flags, since they only |
| * change the place a node is allocated from within a suitable hole. |
| * |
| * Warning: |
| * As long as the scan list is non-empty, no other operations than |
| * adding/removing nodes to/from the scan list are allowed. |
| */ |
| void drm_mm_init_scan_with_range(struct drm_mm *mm, |
| u64 size, |
| unsigned alignment, |
| unsigned long color, |
| u64 start, |
| u64 end) |
| { |
| mm->scan_color = color; |
| mm->scan_alignment = alignment; |
| mm->scan_size = size; |
| mm->scanned_blocks = 0; |
| mm->scan_hit_start = 0; |
| mm->scan_hit_end = 0; |
| mm->scan_start = start; |
| mm->scan_end = end; |
| mm->scan_check_range = 1; |
| mm->prev_scanned_node = NULL; |
| } |
| EXPORT_SYMBOL(drm_mm_init_scan_with_range); |
| |
| /** |
| * drm_mm_scan_add_block - add a node to the scan list |
| * @node: drm_mm_node to add |
| * |
| * Add a node to the scan list that might be freed to make space for the desired |
| * hole. |
| * |
| * Returns: |
| * True if a hole has been found, false otherwise. |
| */ |
| bool drm_mm_scan_add_block(struct drm_mm_node *node) |
| { |
| struct drm_mm *mm = node->mm; |
| struct drm_mm_node *prev_node; |
| u64 hole_start, hole_end; |
| u64 adj_start, adj_end; |
| |
| mm->scanned_blocks++; |
| |
| BUG_ON(node->scanned_block); |
| node->scanned_block = 1; |
| |
| prev_node = list_entry(node->node_list.prev, struct drm_mm_node, |
| node_list); |
| |
| node->scanned_preceeds_hole = prev_node->hole_follows; |
| prev_node->hole_follows = 1; |
| list_del(&node->node_list); |
| node->node_list.prev = &prev_node->node_list; |
| node->node_list.next = &mm->prev_scanned_node->node_list; |
| mm->prev_scanned_node = node; |
| |
| adj_start = hole_start = drm_mm_hole_node_start(prev_node); |
| adj_end = hole_end = drm_mm_hole_node_end(prev_node); |
| |
| if (mm->scan_check_range) { |
| if (adj_start < mm->scan_start) |
| adj_start = mm->scan_start; |
| if (adj_end > mm->scan_end) |
| adj_end = mm->scan_end; |
| } |
| |
| if (mm->color_adjust) |
| mm->color_adjust(prev_node, mm->scan_color, |
| &adj_start, &adj_end); |
| |
| if (check_free_hole(adj_start, adj_end, |
| mm->scan_size, mm->scan_alignment)) { |
| mm->scan_hit_start = hole_start; |
| mm->scan_hit_end = hole_end; |
| return true; |
| } |
| |
| return false; |
| } |
| EXPORT_SYMBOL(drm_mm_scan_add_block); |
| |
| /** |
| * drm_mm_scan_remove_block - remove a node from the scan list |
| * @node: drm_mm_node to remove |
| * |
| * Nodes _must_ be removed in the exact same order from the scan list as they |
| * have been added, otherwise the internal state of the memory manager will be |
| * corrupted. |
| * |
| * When the scan list is empty, the selected memory nodes can be freed. An |
| * immediately following drm_mm_search_free with !DRM_MM_SEARCH_BEST will then |
| * return the just freed block (because its at the top of the free_stack list). |
| * |
| * Returns: |
| * 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_node *node) |
| { |
| struct drm_mm *mm = node->mm; |
| struct drm_mm_node *prev_node; |
| |
| mm->scanned_blocks--; |
| |
| BUG_ON(!node->scanned_block); |
| node->scanned_block = 0; |
| |
| prev_node = list_entry(node->node_list.prev, struct drm_mm_node, |
| node_list); |
| |
| prev_node->hole_follows = node->scanned_preceeds_hole; |
| list_add(&node->node_list, &prev_node->node_list); |
| |
| return (drm_mm_hole_node_end(node) > mm->scan_hit_start && |
| node->start < mm->scan_hit_end); |
| } |
| EXPORT_SYMBOL(drm_mm_scan_remove_block); |
| |
| /** |
| * drm_mm_clean - checks whether an allocator is clean |
| * @mm: drm_mm allocator to check |
| * |
| * Returns: |
| * True if the allocator is completely free, false if there's still a node |
| * allocated in it. |
| */ |
| bool drm_mm_clean(struct drm_mm * mm) |
| { |
| struct list_head *head = &mm->head_node.node_list; |
| |
| return (head->next->next == head); |
| } |
| EXPORT_SYMBOL(drm_mm_clean); |
| |
| /** |
| * drm_mm_init - initialize a drm-mm allocator |
| * @mm: the drm_mm structure to initialize |
| * @start: start of the range managed by @mm |
| * @size: end of the range managed by @mm |
| * |
| * Note that @mm must be cleared to 0 before calling this function. |
| */ |
| void drm_mm_init(struct drm_mm * mm, u64 start, u64 size) |
| { |
| INIT_LIST_HEAD(&mm->hole_stack); |
| mm->scanned_blocks = 0; |
| |
| /* Clever trick to avoid a special case in the free hole tracking. */ |
| INIT_LIST_HEAD(&mm->head_node.node_list); |
| mm->head_node.hole_follows = 1; |
| mm->head_node.scanned_block = 0; |
| mm->head_node.scanned_prev_free = 0; |
| mm->head_node.scanned_next_free = 0; |
| mm->head_node.mm = mm; |
| mm->head_node.start = start + size; |
| mm->head_node.size = start - mm->head_node.start; |
| list_add_tail(&mm->head_node.hole_stack, &mm->hole_stack); |
| |
| mm->interval_tree = RB_ROOT; |
| |
| mm->color_adjust = NULL; |
| } |
| 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(!list_empty(&mm->head_node.node_list), |
| "Memory manager not clean during takedown.\n")) |
| show_leaks(mm); |
| |
| } |
| EXPORT_SYMBOL(drm_mm_takedown); |
| |
| static u64 drm_mm_debug_hole(struct drm_mm_node *entry, |
| const char *prefix) |
| { |
| u64 hole_start, hole_end, hole_size; |
| |
| if (entry->hole_follows) { |
| hole_start = drm_mm_hole_node_start(entry); |
| hole_end = drm_mm_hole_node_end(entry); |
| hole_size = hole_end - hole_start; |
| pr_debug("%s %#llx-%#llx: %llu: free\n", prefix, hole_start, |
| hole_end, hole_size); |
| return hole_size; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * drm_mm_debug_table - dump allocator state to dmesg |
| * @mm: drm_mm allocator to dump |
| * @prefix: prefix to use for dumping to dmesg |
| */ |
| void drm_mm_debug_table(struct drm_mm *mm, const char *prefix) |
| { |
| struct drm_mm_node *entry; |
| u64 total_used = 0, total_free = 0, total = 0; |
| |
| total_free += drm_mm_debug_hole(&mm->head_node, prefix); |
| |
| drm_mm_for_each_node(entry, mm) { |
| pr_debug("%s %#llx-%#llx: %llu: used\n", prefix, entry->start, |
| entry->start + entry->size, entry->size); |
| total_used += entry->size; |
| total_free += drm_mm_debug_hole(entry, prefix); |
| } |
| total = total_free + total_used; |
| |
| pr_debug("%s total: %llu, used %llu free %llu\n", prefix, total, |
| total_used, total_free); |
| } |
| EXPORT_SYMBOL(drm_mm_debug_table); |
| |
| #if defined(CONFIG_DEBUG_FS) |
| static u64 drm_mm_dump_hole(struct seq_file *m, struct drm_mm_node *entry) |
| { |
| u64 hole_start, hole_end, hole_size; |
| |
| if (entry->hole_follows) { |
| hole_start = drm_mm_hole_node_start(entry); |
| hole_end = drm_mm_hole_node_end(entry); |
| hole_size = hole_end - hole_start; |
| seq_printf(m, "%#018llx-%#018llx: %llu: free\n", hole_start, |
| hole_end, hole_size); |
| return hole_size; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * drm_mm_dump_table - dump allocator state to a seq_file |
| * @m: seq_file to dump to |
| * @mm: drm_mm allocator to dump |
| */ |
| int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm) |
| { |
| struct drm_mm_node *entry; |
| u64 total_used = 0, total_free = 0, total = 0; |
| |
| total_free += drm_mm_dump_hole(m, &mm->head_node); |
| |
| drm_mm_for_each_node(entry, mm) { |
| seq_printf(m, "%#018llx-%#018llx: %llu: used\n", entry->start, |
| entry->start + entry->size, entry->size); |
| total_used += entry->size; |
| total_free += drm_mm_dump_hole(m, entry); |
| } |
| total = total_free + total_used; |
| |
| seq_printf(m, "total: %llu, used %llu free %llu\n", total, |
| total_used, total_free); |
| return 0; |
| } |
| EXPORT_SYMBOL(drm_mm_dump_table); |
| #endif |