/************************************************************************** * * 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 */ #include #include #include #include #include extern int drm_vma_debug; /** * 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 on 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. */ static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm, u64 size, u64 alignment, unsigned long color, u64 start, u64 end, enum drm_mm_search_flags flags); #ifdef CONFIG_DRM_DEBUG_MM #include #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, M_DRM, GFP_KERNEL); if (!buf) return; list_for_each_entry(node, drm_mm_nodes(mm), node_list) { struct stack_trace trace = { .entries = entries, .max_entries = STACKDEPTH }; if (!node->stack) { DRM_ERROR("node [%08llx + %08llx]: unknown owner\n", node->start, node->size); continue; } depot_fetch_stack(node->stack, &trace); snprint_stack_trace(buf, BUFSZ, &trace, 0); DRM_ERROR("node [%08llx + %08llx]: inserted at\n%s", node->start, node->size, buf); } kfree(buf); } #undef STACKDEPTH #undef BUFSZ #else static void save_stack(struct drm_mm_node *node) { } static void show_leaks(struct drm_mm *mm) { } #endif #define START(node) ((node)->start) #define LAST(node) ((node)->start + (node)->size - 1) #ifndef __DragonFly__ INTERVAL_TREE_DEFINE(struct drm_mm_node, rb, u64, __subtree_last, START, LAST, static inline, drm_mm_interval_tree) #else static struct drm_mm_node * drm_mm_interval_tree_iter_first(struct rb_root *rb, u64 start, u64 last) { struct drm_mm *mm = container_of(rb, typeof(*mm), interval_tree); struct drm_mm_node *node; drm_mm_for_each_node(node, mm) { if (LAST(node) >= start && START(node) <= last) return node; } return NULL; } #endif 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 *)&mm->interval_tree, start, last) ?: (struct drm_mm_node *)&mm->head_node; } EXPORT_SYMBOL(__drm_mm_interval_first); static void drm_mm_insert_helper(struct drm_mm_node *hole_node, struct drm_mm_node *node, u64 size, u64 alignment, unsigned long color, u64 range_start, u64 range_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; DRM_MM_BUG_ON(!drm_mm_hole_follows(hole_node) || node->allocated); if (mm->color_adjust) mm->color_adjust(hole_node, color, &adj_start, &adj_end); adj_start = max(adj_start, range_start); adj_end = min(adj_end, range_end); if (flags & DRM_MM_CREATE_TOP) adj_start = adj_end - size; if (alignment) { u64 rem; div64_u64_rem(adj_start, alignment, &rem); 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_BUG_ON(node->start < range_start); DRM_MM_BUG_ON(node->start < adj_start); DRM_MM_BUG_ON(node->start + node->size > adj_end); DRM_MM_BUG_ON(node->start + node->size > range_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. All other * fields must be cleared to 0. This is useful to initialize the allocator with * preallocated objects which must be set-up before the range allocator can be * set-up, e.g. when taking over a firmware framebuffer. * * Returns: * 0 on success, -ENOSPC if there's no hole where @node is. */ int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node) { u64 end = node->start + node->size; struct drm_mm_node *hole; u64 hole_start, hole_end; u64 adj_start, adj_end; end = node->start + node->size; if (unlikely(end <= node->start)) return -ENOSPC; /* Find the relevant hole to add our node to */ hole = 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(drm_mm_nodes(mm), typeof(*hole), node_list); } hole = list_last_entry(&hole->node_list, typeof(*hole), node_list); if (!drm_mm_hole_follows(hole)) return -ENOSPC; adj_start = hole_start = __drm_mm_hole_node_start(hole); adj_end = hole_end = __drm_mm_hole_node_end(hole); 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; node->allocated = 1; list_add(&node->node_list, &hole->node_list); #if 0 drm_mm_interval_tree_add_node(hole, node); #endif 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_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, u64 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(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 unallocated node. */ void drm_mm_remove_node(struct drm_mm_node *node) { struct drm_mm *mm = node->mm; struct drm_mm_node *prev_node; if (drm_vma_debug & 2) { drm_vma_debug &= ~2; } DRM_MM_BUG_ON(!node->allocated); DRM_MM_BUG_ON(node->scanned_block); prev_node = list_entry(node->node_list.prev, struct drm_mm_node, node_list); if (drm_mm_hole_follows(node)) { DRM_MM_BUG_ON(__drm_mm_hole_node_start(node) == __drm_mm_hole_node_end(node)); list_del(&node->hole_stack); } else { DRM_MM_BUG_ON(__drm_mm_hole_node_start(node) != __drm_mm_hole_node_end(node)); } if (!drm_mm_hole_follows(prev_node)) { prev_node->hole_follows = 1; list_add(&prev_node->hole_stack, &mm->hole_stack); } else list_move(&prev_node->hole_stack, &mm->hole_stack); 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, u64 alignment) { if (end - start < size) return 0; if (alignment) { u64 rem; div64_u64_rem(start, alignment, &rem); if (rem) start += alignment - rem; } return end >= start + size; } static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm, u64 size, u64 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; DRM_MM_BUG_ON(mm->scan_active); 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; } adj_start = max(adj_start, start); adj_end = min(adj_end, end); 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) { DRM_MM_BUG_ON(!old->allocated); list_replace(&old->node_list, &new->node_list); list_replace(&old->hole_stack, &new->hole_stack); new->hole_follows = old->hole_follows; new->mm = old->mm; new->start = old->start; new->size = old->size; new->color = old->color; old->allocated = 0; new->allocated = 1; } EXPORT_SYMBOL(drm_mm_replace_node); /** * DOC: lru scan roster * * Very often GPUs need to have continuous allocations for a given object. When * evicting objects to make space for a new one it is therefore not most * efficient when we simply start to select all objects from the tail of an LRU * until there's a suitable hole: Especially for big objects or nodes that * otherwise have special allocation constraints there's a good chance we evict * lots of (smaller) objects unnecessarily. * * The DRM range allocator supports this use-case through the scanning * interfaces. First a scan operation needs to be initialized with * drm_mm_scan_init() or drm_mm_scan_init_with_range(). The driver adds * objects to the roster, probably by walking an LRU list, but this can be * freely implemented. Eviction candiates are added using * drm_mm_scan_add_block() until a suitable hole is found or there are no * further evictable objects. Eviction roster metadata is tracked in struct * &drm_mm_scan. * * The driver must walk through all objects again in exactly the reverse * order to restore the allocator state. Note that while the allocator is used * in the scan mode no other operation is allowed. * * Finally the driver evicts all objects selected (drm_mm_scan_remove_block() * reported true) in the scan, and any overlapping nodes after color adjustment * (drm_mm_scan_color_evict()). Adding and removing an object is O(1), and * since freeing a node is also O(1) the overall complexity is * O(scanned_objects). So like the free stack which needs to be walked before a * scan operation even begins this is linear in the number of objects. It * doesn't seem to hurt too badly. */ /** * drm_mm_scan_init_with_range - initialize range-restricted lru scanning * @scan: scan state * @mm: drm_mm to scan * @size: size of the allocation * @alignment: alignment of the allocation * @color: opaque tag value to use for the allocation * @start: start of the allowed range for the allocation * @end: end of the allowed range for the allocation * @flags: flags to specify how the allocation will be performed afterwards * * 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, unsigned int flags) { 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->flags = flags; DRM_MM_BUG_ON(end <= start); scan->range_start = start; scan->range_end = end; scan->hit_start = U64_MAX; scan->hit_end = 0; } EXPORT_SYMBOL(drm_mm_scan_init_with_range); /** * drm_mm_scan_add_block - add a node to the scan list * @scan: the active drm_mm scanner * @node: drm_mm_node to add * * Add a node to the scan list that might be freed to make space for the desired * hole. * * Returns: * True if a hole has been found, false otherwise. */ bool drm_mm_scan_add_block(struct drm_mm_scan *scan, struct drm_mm_node *node) { struct drm_mm *mm = scan->mm; struct drm_mm_node *hole; u64 hole_start, hole_end; u64 col_start, col_end; u64 adj_start, adj_end; DRM_MM_BUG_ON(node->mm != mm); DRM_MM_BUG_ON(!node->allocated); DRM_MM_BUG_ON(node->scanned_block); node->scanned_block = true; mm->scan_active++; /* Remove this block from the node_list so that we enlarge the hole * (distance between the end of our previous node and the start of * or next), without poisoning the link so that we can restore it * later in drm_mm_scan_remove_block(). */ hole = list_prev_entry(node, node_list); DRM_MM_BUG_ON(list_next_entry(hole, node_list) != node); __list_del_entry(&node->node_list); hole_start = __drm_mm_hole_node_start(hole); hole_end = __drm_mm_hole_node_end(hole); col_start = hole_start; col_end = hole_end; if (mm->color_adjust) mm->color_adjust(hole, scan->color, &col_start, &col_end); adj_start = max(col_start, scan->range_start); adj_end = min(col_end, scan->range_end); if (adj_end <= adj_start || adj_end - adj_start < scan->size) return false; if (scan->flags == DRM_MM_CREATE_TOP) 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->flags != DRM_MM_CREATE_TOP) adj_start += scan->alignment; if (adj_start < max(col_start, scan->range_start) || min(col_end, scan->range_end) - adj_start < scan->size) return false; if (adj_end <= adj_start || adj_end - adj_start < scan->size) return false; } } scan->hit_start = adj_start; scan->hit_end = adj_start + scan->size; DRM_MM_BUG_ON(scan->hit_start >= scan->hit_end); DRM_MM_BUG_ON(scan->hit_start < hole_start); DRM_MM_BUG_ON(scan->hit_end > hole_end); return true; } EXPORT_SYMBOL(drm_mm_scan_add_block); /** * drm_mm_scan_remove_block - remove a node from the scan list * @scan: the active drm_mm scanner * @node: drm_mm_node to remove * * Nodes **must** be removed in exactly the reverse order from the scan list as * they have been added (e.g. using list_add() as they are added and then * list_for_each() over that eviction list to remove), otherwise the internal * state of the memory manager will be corrupted. * * When the scan list is empty, the selected memory nodes can be freed. An * immediately following drm_mm_insert_node_in_range_generic() or one of the * simpler versions of that function with !DRM_MM_SEARCH_BEST will then return * the just freed block (because its at the top of the free_stack list). * * Returns: * True if this block should be evicted, false otherwise. Will always * return false when no hole has been found. */ bool drm_mm_scan_remove_block(struct drm_mm_scan *scan, struct drm_mm_node *node) { struct drm_mm_node *prev_node; DRM_MM_BUG_ON(node->mm != scan->mm); DRM_MM_BUG_ON(!node->scanned_block); node->scanned_block = false; DRM_MM_BUG_ON(!node->mm->scan_active); node->mm->scan_active--; /* During drm_mm_scan_add_block() we decoupled this node leaving * its pointers intact. Now that the caller is walking back along * the eviction list we can restore this block into its rightful * place on the full node_list. To confirm that the caller is walking * backwards correctly we check that prev_node->next == node->next, * i.e. both believe the same node should be on the other side of the * hole. */ prev_node = list_prev_entry(node, node_list); DRM_MM_BUG_ON(list_next_entry(prev_node, node_list) != list_next_entry(node, node_list)); list_add(&node->node_list, &prev_node->node_list); return (node->start + node->size > scan->hit_start && node->start < scan->hit_end); } EXPORT_SYMBOL(drm_mm_scan_remove_block); /** * drm_mm_scan_color_evict - evict overlapping nodes on either side of hole * @scan: drm_mm scan with target hole * * After completing an eviction scan and removing the selected nodes, we may * need to remove a few more nodes from either side of the target hole if * mm.color_adjust is being used. * * Returns: * A node to evict, or NULL if there are no overlapping nodes. */ struct drm_mm_node *drm_mm_scan_color_evict(struct drm_mm_scan *scan) { struct drm_mm *mm = scan->mm; struct drm_mm_node *hole; u64 hole_start, hole_end; DRM_MM_BUG_ON(list_empty(&mm->hole_stack)); if (!mm->color_adjust) return NULL; hole = list_first_entry(&mm->hole_stack, typeof(*hole), hole_stack); hole_start = __drm_mm_hole_node_start(hole); hole_end = __drm_mm_hole_node_end(hole); 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); INIT_LIST_HEAD(&mm->hole_stack); mm->scan_active = 0; /* Clever trick to avoid a special case in the free hole tracking. */ INIT_LIST_HEAD(&mm->head_node.node_list); INIT_LIST_HEAD(&mm->head_node.hole_stack); mm->head_node.allocated = 0; mm->head_node.hole_follows = 1; 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->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(!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, 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; drm_printf(p, "%#018llx-%#018llx: %llu: free\n", hole_start, hole_end, hole_size); return hole_size; } return 0; } /** * drm_mm_print - print allocator state * @mm: drm_mm allocator to print * @p: DRM printer to use */ void drm_mm_print(struct drm_mm *mm, struct drm_printer *p) { 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);