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| -rw-r--r-- | include/drm/drm_mm.h | 551 |
1 files changed, 551 insertions, 0 deletions
diff --git a/include/drm/drm_mm.h b/include/drm/drm_mm.h new file mode 100644 index 000000000..9b4292f22 --- /dev/null +++ b/include/drm/drm_mm.h @@ -0,0 +1,551 @@ +/************************************************************************** + * + * Copyright 2006-2008 Tungsten Graphics, Inc., Cedar Park, TX. 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. + * + * + **************************************************************************/ +/* + * Authors: + * Thomas Hellstrom <thomas-at-tungstengraphics-dot-com> + */ + +#ifndef _DRM_MM_H_ +#define _DRM_MM_H_ + +/* + * Generic range manager structs + */ +#include <linux/bug.h> +#include <linux/rbtree.h> +#include <linux/kernel.h> +#include <linux/mm_types.h> +#include <linux/list.h> +#include <linux/spinlock.h> +#ifdef CONFIG_DRM_DEBUG_MM +#include <linux/stackdepot.h> +#endif +#include <drm/drm_print.h> + +#ifdef CONFIG_DRM_DEBUG_MM +#define DRM_MM_BUG_ON(expr) BUG_ON(expr) +#else +#define DRM_MM_BUG_ON(expr) BUILD_BUG_ON_INVALID(expr) +#endif + +/** + * enum drm_mm_insert_mode - control search and allocation behaviour + * + * The &struct drm_mm range manager supports finding a suitable modes using + * a number of search trees. These trees are oranised by size, by address and + * in most recent eviction order. This allows the user to find either the + * smallest hole to reuse, the lowest or highest address to reuse, or simply + * reuse the most recent eviction that fits. When allocating the &drm_mm_node + * from within the hole, the &drm_mm_insert_mode also dictate whether to + * allocate the lowest matching address or the highest. + */ +enum drm_mm_insert_mode { + /** + * @DRM_MM_INSERT_BEST: + * + * Search for the smallest hole (within the search range) that fits + * the desired node. + * + * Allocates the node from the bottom of the found hole. + */ + DRM_MM_INSERT_BEST = 0, + + /** + * @DRM_MM_INSERT_LOW: + * + * Search for the lowest hole (address closest to 0, within the search + * range) that fits the desired node. + * + * Allocates the node from the bottom of the found hole. + */ + DRM_MM_INSERT_LOW, + + /** + * @DRM_MM_INSERT_HIGH: + * + * Search for the highest hole (address closest to U64_MAX, within the + * search range) that fits the desired node. + * + * Allocates the node from the *top* of the found hole. The specified + * alignment for the node is applied to the base of the node + * (&drm_mm_node.start). + */ + DRM_MM_INSERT_HIGH, + + /** + * @DRM_MM_INSERT_EVICT: + * + * Search for the most recently evicted hole (within the search range) + * that fits the desired node. This is appropriate for use immediately + * after performing an eviction scan (see drm_mm_scan_init()) and + * removing the selected nodes to form a hole. + * + * Allocates the node from the bottom of the found hole. + */ + DRM_MM_INSERT_EVICT, + + /** + * @DRM_MM_INSERT_ONCE: + * + * Only check the first hole for suitablity and report -ENOSPC + * immediately otherwise, rather than check every hole until a + * suitable one is found. Can only be used in conjunction with another + * search method such as DRM_MM_INSERT_HIGH or DRM_MM_INSERT_LOW. + */ + DRM_MM_INSERT_ONCE = BIT(31), + + /** + * @DRM_MM_INSERT_HIGHEST: + * + * Only check the highest hole (the hole with the largest address) and + * insert the node at the top of the hole or report -ENOSPC if + * unsuitable. + * + * Does not search all holes. + */ + DRM_MM_INSERT_HIGHEST = DRM_MM_INSERT_HIGH | DRM_MM_INSERT_ONCE, + + /** + * @DRM_MM_INSERT_LOWEST: + * + * Only check the lowest hole (the hole with the smallest address) and + * insert the node at the bottom of the hole or report -ENOSPC if + * unsuitable. + * + * Does not search all holes. + */ + DRM_MM_INSERT_LOWEST = DRM_MM_INSERT_LOW | DRM_MM_INSERT_ONCE, +}; + +/** + * struct drm_mm_node - allocated block in the DRM allocator + * + * This represents an allocated block in a &drm_mm allocator. Except for + * pre-reserved nodes inserted using drm_mm_reserve_node() the structure is + * entirely opaque and should only be accessed through the provided funcions. + * Since allocation of these nodes is entirely handled by the driver they can be + * embedded. + */ +struct drm_mm_node { + /** @color: Opaque driver-private tag. */ + unsigned long color; + /** @start: Start address of the allocated block. */ + u64 start; + /** @size: Size of the allocated block. */ + u64 size; + /* private: */ + struct drm_mm *mm; + struct list_head node_list; + struct list_head hole_stack; + struct rb_node rb; + struct rb_node rb_hole_size; + struct rb_node rb_hole_addr; + u64 __subtree_last; + u64 hole_size; + u64 subtree_max_hole; + unsigned long flags; +#define DRM_MM_NODE_ALLOCATED_BIT 0 +#define DRM_MM_NODE_SCANNED_BIT 1 +#ifdef CONFIG_DRM_DEBUG_MM + depot_stack_handle_t stack; +#endif +}; + +/** + * struct drm_mm - DRM allocator + * + * DRM range allocator with a few special functions and features geared towards + * managing GPU memory. Except for the @color_adjust callback the structure is + * entirely opaque and should only be accessed through the provided functions + * and macros. This structure can be embedded into larger driver structures. + */ +struct drm_mm { + /** + * @color_adjust: + * + * Optional driver callback to further apply restrictions on a hole. The + * node argument points at the node containing the hole from which the + * block would be allocated (see drm_mm_hole_follows() and friends). The + * other arguments are the size of the block to be allocated. The driver + * can adjust the start and end as needed to e.g. insert guard pages. + */ + void (*color_adjust)(const struct drm_mm_node *node, + unsigned long color, + u64 *start, u64 *end); + + /* private: */ + /* List of all memory nodes that immediately precede a free hole. */ + struct list_head hole_stack; + /* head_node.node_list is the list of all memory nodes, ordered + * according to the (increasing) start address of the memory node. */ + struct drm_mm_node head_node; + /* Keep an interval_tree for fast lookup of drm_mm_nodes by address. */ + struct rb_root_cached interval_tree; + struct rb_root_cached holes_size; + struct rb_root holes_addr; + + unsigned long scan_active; +}; + +/** + * struct drm_mm_scan - DRM allocator eviction roaster data + * + * This structure tracks data needed for the eviction roaster set up using + * drm_mm_scan_init(), and used with drm_mm_scan_add_block() and + * drm_mm_scan_remove_block(). The structure is entirely opaque and should only + * be accessed through the provided functions and macros. It is meant to be + * allocated temporarily by the driver on the stack. + */ +struct drm_mm_scan { + /* private: */ + struct drm_mm *mm; + + u64 size; + u64 alignment; + u64 remainder_mask; + + u64 range_start; + u64 range_end; + + u64 hit_start; + u64 hit_end; + + unsigned long color; + enum drm_mm_insert_mode mode; +}; + +/** + * drm_mm_node_allocated - checks whether a node is allocated + * @node: drm_mm_node to check + * + * Drivers are required to clear a node prior to using it with the + * drm_mm range manager. + * + * Drivers should use this helper for proper encapsulation of drm_mm + * internals. + * + * Returns: + * True if the @node is allocated. + */ +static inline bool drm_mm_node_allocated(const struct drm_mm_node *node) +{ + return test_bit(DRM_MM_NODE_ALLOCATED_BIT, &node->flags); +} + +/** + * drm_mm_initialized - checks whether an allocator is initialized + * @mm: drm_mm to check + * + * Drivers should clear the struct drm_mm prior to initialisation if they + * want to use this function. + * + * Drivers should use this helper for proper encapsulation of drm_mm + * internals. + * + * Returns: + * True if the @mm is initialized. + */ +static inline bool drm_mm_initialized(const struct drm_mm *mm) +{ + return READ_ONCE(mm->hole_stack.next); +} + +/** + * drm_mm_hole_follows - checks whether a hole follows this node + * @node: drm_mm_node to check + * + * Holes are embedded into the drm_mm using the tail of a drm_mm_node. + * If you wish to know whether a hole follows this particular node, + * query this function. See also drm_mm_hole_node_start() and + * drm_mm_hole_node_end(). + * + * Returns: + * True if a hole follows the @node. + */ +static inline bool drm_mm_hole_follows(const struct drm_mm_node *node) +{ + return node->hole_size; +} + +static inline u64 __drm_mm_hole_node_start(const struct drm_mm_node *hole_node) +{ + return hole_node->start + hole_node->size; +} + +/** + * drm_mm_hole_node_start - computes the start of the hole following @node + * @hole_node: drm_mm_node which implicitly tracks the following hole + * + * This is useful for driver-specific debug dumpers. Otherwise drivers should + * not inspect holes themselves. Drivers must check first whether a hole indeed + * follows by looking at drm_mm_hole_follows() + * + * Returns: + * Start of the subsequent hole. + */ +static inline u64 drm_mm_hole_node_start(const struct drm_mm_node *hole_node) +{ + DRM_MM_BUG_ON(!drm_mm_hole_follows(hole_node)); + return __drm_mm_hole_node_start(hole_node); +} + +static inline u64 __drm_mm_hole_node_end(const struct drm_mm_node *hole_node) +{ + return list_next_entry(hole_node, node_list)->start; +} + +/** + * drm_mm_hole_node_end - computes the end of the hole following @node + * @hole_node: drm_mm_node which implicitly tracks the following hole + * + * This is useful for driver-specific debug dumpers. Otherwise drivers should + * not inspect holes themselves. Drivers must check first whether a hole indeed + * follows by looking at drm_mm_hole_follows(). + * + * Returns: + * End of the subsequent hole. + */ +static inline u64 drm_mm_hole_node_end(const struct drm_mm_node *hole_node) +{ + return __drm_mm_hole_node_end(hole_node); +} + +/** + * drm_mm_nodes - list of nodes under the drm_mm range manager + * @mm: the struct drm_mm range manager + * + * As the drm_mm range manager hides its node_list deep with its + * structure, extracting it looks painful and repetitive. This is + * not expected to be used outside of the drm_mm_for_each_node() + * macros and similar internal functions. + * + * Returns: + * The node list, may be empty. + */ +#define drm_mm_nodes(mm) (&(mm)->head_node.node_list) + +/** + * drm_mm_for_each_node - iterator to walk over all allocated nodes + * @entry: &struct drm_mm_node to assign to in each iteration step + * @mm: &drm_mm allocator to walk + * + * This iterator walks over all nodes in the range allocator. It is implemented + * with list_for_each(), so not save against removal of elements. + */ +#define drm_mm_for_each_node(entry, mm) \ + list_for_each_entry(entry, drm_mm_nodes(mm), node_list) + +/** + * drm_mm_for_each_node_safe - iterator to walk over all allocated nodes + * @entry: &struct drm_mm_node to assign to in each iteration step + * @next: &struct drm_mm_node to store the next step + * @mm: &drm_mm allocator to walk + * + * This iterator walks over all nodes in the range allocator. It is implemented + * with list_for_each_safe(), so save against removal of elements. + */ +#define drm_mm_for_each_node_safe(entry, next, mm) \ + list_for_each_entry_safe(entry, next, drm_mm_nodes(mm), node_list) + +/** + * drm_mm_for_each_hole - iterator to walk over all holes + * @pos: &drm_mm_node used internally to track progress + * @mm: &drm_mm allocator to walk + * @hole_start: ulong variable to assign the hole start to on each iteration + * @hole_end: ulong variable to assign the hole end to on each iteration + * + * This iterator walks over all holes in the range allocator. It is implemented + * with list_for_each(), so not save against removal of elements. @entry is used + * internally and will not reflect a real drm_mm_node for the very first hole. + * Hence users of this iterator may not access it. + * + * Implementation Note: + * We need to inline list_for_each_entry in order to be able to set hole_start + * and hole_end on each iteration while keeping the macro sane. + */ +#define drm_mm_for_each_hole(pos, mm, hole_start, hole_end) \ + for (pos = list_first_entry(&(mm)->hole_stack, \ + typeof(*pos), hole_stack); \ + &pos->hole_stack != &(mm)->hole_stack ? \ + hole_start = drm_mm_hole_node_start(pos), \ + hole_end = hole_start + pos->hole_size, \ + 1 : 0; \ + pos = list_next_entry(pos, hole_stack)) + +/* + * Basic range manager support (drm_mm.c) + */ +int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node); +int drm_mm_insert_node_in_range(struct drm_mm *mm, + struct drm_mm_node *node, + u64 size, + u64 alignment, + unsigned long color, + u64 start, + u64 end, + enum drm_mm_insert_mode mode); + +/** + * 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 + * @mode: fine-tune the allocation search and placement + * + * This is a simplified version of drm_mm_insert_node_in_range() with no + * range restrictions applied. + * + * The preallocated node must be cleared to 0. + * + * Returns: + * 0 on success, -ENOSPC if there's no suitable hole. + */ +static inline int +drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node, + u64 size, u64 alignment, + unsigned long color, + enum drm_mm_insert_mode mode) +{ + return drm_mm_insert_node_in_range(mm, node, + size, alignment, color, + 0, U64_MAX, mode); +} + +/** + * drm_mm_insert_node - search for space and insert @node + * @mm: drm_mm to allocate from + * @node: preallocate node to insert + * @size: size of the allocation + * + * This is a simplified version of drm_mm_insert_node_generic() with @color set + * to 0. + * + * The preallocated node must be cleared to 0. + * + * Returns: + * 0 on success, -ENOSPC if there's no suitable hole. + */ +static inline int drm_mm_insert_node(struct drm_mm *mm, + struct drm_mm_node *node, + u64 size) +{ + return drm_mm_insert_node_generic(mm, node, size, 0, 0, 0); +} + +void drm_mm_remove_node(struct drm_mm_node *node); +void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new); +void drm_mm_init(struct drm_mm *mm, u64 start, u64 size); +void drm_mm_takedown(struct drm_mm *mm); + +/** + * 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. + */ +static inline bool drm_mm_clean(const struct drm_mm *mm) +{ + return list_empty(drm_mm_nodes(mm)); +} + +struct drm_mm_node * +__drm_mm_interval_first(const struct drm_mm *mm, u64 start, u64 last); + +/** + * drm_mm_for_each_node_in_range - iterator to walk over a range of + * allocated nodes + * @node__: drm_mm_node structure to assign to in each iteration step + * @mm__: drm_mm allocator to walk + * @start__: starting offset, the first node will overlap this + * @end__: ending offset, the last node will start before this (but may overlap) + * + * This iterator walks over all nodes in the range allocator that lie + * between @start and @end. It is implemented similarly to list_for_each(), + * but using the internal interval tree to accelerate the search for the + * starting node, and so not safe against removal of elements. It assumes + * that @end is within (or is the upper limit of) the drm_mm allocator. + * If [@start, @end] are beyond the range of the drm_mm, the iterator may walk + * over the special _unallocated_ &drm_mm.head_node, and may even continue + * indefinitely. + */ +#define drm_mm_for_each_node_in_range(node__, mm__, start__, end__) \ + for (node__ = __drm_mm_interval_first((mm__), (start__), (end__)-1); \ + node__->start < (end__); \ + node__ = list_next_entry(node__, node_list)) + +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_scan_init - initialize 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 + * @mode: fine-tune the allocation search and placement + * + * This is a simplified version of drm_mm_scan_init_with_range() with no range + * restrictions applied. + * + * 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. + */ +static inline void drm_mm_scan_init(struct drm_mm_scan *scan, + struct drm_mm *mm, + u64 size, + u64 alignment, + unsigned long color, + enum drm_mm_insert_mode mode) +{ + drm_mm_scan_init_with_range(scan, mm, + size, alignment, color, + 0, U64_MAX, mode); +} + +bool drm_mm_scan_add_block(struct drm_mm_scan *scan, + struct drm_mm_node *node); +bool drm_mm_scan_remove_block(struct drm_mm_scan *scan, + struct drm_mm_node *node); +struct drm_mm_node *drm_mm_scan_color_evict(struct drm_mm_scan *scan); + +void drm_mm_print(const struct drm_mm *mm, struct drm_printer *p); + +#endif |