| 47,7 → 47,48 |
|---|
| #include <linux/seq_file.h> |
| #include <linux/export.h> |
| |
| #define MM_UNUSED_TARGET 4 |
| /** |
| * 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, |
| unsigned long size, |
| 65,7 → 106,8 |
|---|
| static void drm_mm_insert_helper(struct drm_mm_node *hole_node, |
| struct drm_mm_node *node, |
| unsigned long size, unsigned alignment, |
| unsigned long color) |
| unsigned long color, |
| enum drm_mm_allocator_flags flags) |
| { |
| struct drm_mm *mm = hole_node->mm; |
| unsigned long hole_start = drm_mm_hole_node_start(hole_node); |
| 78,12 → 120,22 |
|---|
| 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) { |
| unsigned tmp = adj_start % alignment; |
| if (tmp) |
| if (tmp) { |
| if (flags & DRM_MM_CREATE_TOP) |
| adj_start -= tmp; |
| else |
| adj_start += alignment - tmp; |
| } |
| } |
| |
| 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); |
| 107,6 → 159,20 |
|---|
| } |
| } |
| |
| /** |
| * 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) |
| { |
| struct drm_mm_node *hole; |
| 141,30 → 207,39 |
|---|
| return 0; |
| } |
| |
| WARN(1, "no hole found for node 0x%lx + 0x%lx\n", |
| node->start, node->size); |
| return -ENOSPC; |
| } |
| EXPORT_SYMBOL(drm_mm_reserve_node); |
| |
| /** |
| * Search for free space and insert a preallocated memory node. Returns |
| * -ENOSPC if no suitable free area is available. The preallocated memory node |
| * must be cleared. |
| * 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, |
| unsigned long size, unsigned alignment, |
| unsigned long color, |
| enum drm_mm_search_flags flags) |
| enum drm_mm_search_flags sflags, |
| enum drm_mm_allocator_flags aflags) |
| { |
| struct drm_mm_node *hole_node; |
| |
| hole_node = drm_mm_search_free_generic(mm, size, alignment, |
| color, flags); |
| color, sflags); |
| if (!hole_node) |
| return -ENOSPC; |
| |
| drm_mm_insert_helper(hole_node, node, size, alignment, color); |
| drm_mm_insert_helper(hole_node, node, size, alignment, color, aflags); |
| return 0; |
| } |
| EXPORT_SYMBOL(drm_mm_insert_node_generic); |
| 173,7 → 248,8 |
|---|
| struct drm_mm_node *node, |
| unsigned long size, unsigned alignment, |
| unsigned long color, |
| unsigned long start, unsigned long end) |
| unsigned long start, unsigned long end, |
| enum drm_mm_allocator_flags flags) |
| { |
| struct drm_mm *mm = hole_node->mm; |
| unsigned long hole_start = drm_mm_hole_node_start(hole_node); |
| 188,14 → 264,21 |
|---|
| if (adj_end > end) |
| adj_end = end; |
| |
| if (flags & DRM_MM_CREATE_TOP) |
| adj_start = adj_end - size; |
| |
| if (mm->color_adjust) |
| mm->color_adjust(hole_node, color, &adj_start, &adj_end); |
| |
| if (alignment) { |
| unsigned tmp = adj_start % alignment; |
| if (tmp) |
| if (tmp) { |
| if (flags & DRM_MM_CREATE_TOP) |
| adj_start -= tmp; |
| else |
| adj_start += alignment - tmp; |
| } |
| } |
| |
| if (adj_start == hole_start) { |
| hole_node->hole_follows = 0; |
| 211,6 → 294,8 |
|---|
| INIT_LIST_HEAD(&node->hole_stack); |
| list_add(&node->node_list, &hole_node->node_list); |
| |
| 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); |
| |
| 222,32 → 307,51 |
|---|
| } |
| |
| /** |
| * Search for free space and insert a preallocated memory node. Returns |
| * -ENOSPC if no suitable free area is available. This is for range |
| * restricted allocations. The preallocated memory node must be cleared. |
| * 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, |
| unsigned long size, unsigned alignment, unsigned long color, |
| unsigned long size, unsigned alignment, |
| unsigned long color, |
| unsigned long start, unsigned long end, |
| enum drm_mm_search_flags flags) |
| enum drm_mm_search_flags sflags, |
| enum drm_mm_allocator_flags aflags) |
| { |
| struct drm_mm_node *hole_node; |
| |
| hole_node = drm_mm_search_free_in_range_generic(mm, |
| size, alignment, color, |
| start, end, flags); |
| start, end, sflags); |
| if (!hole_node) |
| return -ENOSPC; |
| |
| drm_mm_insert_helper_range(hole_node, node, |
| size, alignment, color, |
| start, end); |
| start, end, aflags); |
| return 0; |
| } |
| EXPORT_SYMBOL(drm_mm_insert_node_in_range_generic); |
| |
| /** |
| * Remove a memory node from the allocator. |
| * 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) |
| { |
| 315,7 → 419,10 |
|---|
| best = NULL; |
| best_size = ~0UL; |
| |
| drm_mm_for_each_hole(entry, mm, adj_start, adj_end) { |
| __drm_mm_for_each_hole(entry, mm, adj_start, adj_end, |
| flags & DRM_MM_SEARCH_BELOW) { |
| unsigned long hole_size = adj_end - adj_start; |
| |
| if (mm->color_adjust) { |
| mm->color_adjust(entry, color, &adj_start, &adj_end); |
| if (adj_end <= adj_start) |
| 328,9 → 435,9 |
|---|
| if (!(flags & DRM_MM_SEARCH_BEST)) |
| return entry; |
| |
| if (entry->size < best_size) { |
| if (hole_size < best_size) { |
| best = entry; |
| best_size = entry->size; |
| best_size = hole_size; |
| } |
| } |
| |
| 356,7 → 463,10 |
|---|
| best = NULL; |
| best_size = ~0UL; |
| |
| drm_mm_for_each_hole(entry, mm, adj_start, adj_end) { |
| __drm_mm_for_each_hole(entry, mm, adj_start, adj_end, |
| flags & DRM_MM_SEARCH_BELOW) { |
| unsigned long hole_size = adj_end - adj_start; |
| |
| if (adj_start < start) |
| adj_start = start; |
| if (adj_end > end) |
| 374,9 → 484,9 |
|---|
| if (!(flags & DRM_MM_SEARCH_BEST)) |
| return entry; |
| |
| if (entry->size < best_size) { |
| if (hole_size < best_size) { |
| best = entry; |
| best_size = entry->size; |
| best_size = hole_size; |
| } |
| } |
| |
| 384,7 → 494,13 |
|---|
| } |
| |
| /** |
| * Moves an allocation. To be used with embedded struct drm_mm_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) |
| { |
| 402,12 → 518,46 |
|---|
| EXPORT_SYMBOL(drm_mm_replace_node); |
| |
| /** |
| * Initializa lru scanning. |
| * 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. |
| * 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 |
| * 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, |
| 427,12 → 577,20 |
|---|
| EXPORT_SYMBOL(drm_mm_init_scan); |
| |
| /** |
| * Initializa lru scanning. |
| * 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. This version is for range-restricted scans. |
| * 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 |
| * 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, |
| 456,12 → 614,16 |
|---|
| 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 non-zero, if a hole has been found, zero otherwise. |
| * Returns: |
| * True if a hole has been found, false otherwise. |
| */ |
| int drm_mm_scan_add_block(struct drm_mm_node *node) |
| bool drm_mm_scan_add_block(struct drm_mm_node *node) |
| { |
| struct drm_mm *mm = node->mm; |
| struct drm_mm_node *prev_node; |
| 501,15 → 663,16 |
|---|
| mm->scan_size, mm->scan_alignment)) { |
| mm->scan_hit_start = hole_start; |
| mm->scan_hit_end = hole_end; |
| return 1; |
| return true; |
| } |
| |
| return 0; |
| return false; |
| } |
| EXPORT_SYMBOL(drm_mm_scan_add_block); |
| |
| /** |
| * Remove a node from the scan list. |
| * 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 |
| 519,10 → 682,11 |
|---|
| * 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 one if this block should be evicted, zero otherwise. Will always |
| * return zero when no hole has been found. |
| * Returns: |
| * True if this block should be evicted, false otherwise. Will always |
| * return false when no hole has been found. |
| */ |
| int drm_mm_scan_remove_block(struct drm_mm_node *node) |
| bool drm_mm_scan_remove_block(struct drm_mm_node *node) |
| { |
| struct drm_mm *mm = node->mm; |
| struct drm_mm_node *prev_node; |
| 543,7 → 707,15 |
|---|
| } |
| EXPORT_SYMBOL(drm_mm_scan_remove_block); |
| |
| int drm_mm_clean(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. |
| */ |
| bool drm_mm_clean(struct drm_mm * mm) |
| { |
| struct list_head *head = &mm->head_node.node_list; |
| |
| 551,6 → 723,14 |
|---|
| } |
| 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, unsigned long start, unsigned long size) |
| { |
| INIT_LIST_HEAD(&mm->hole_stack); |
| 572,6 → 752,13 |
|---|
| } |
| 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) |
| { |
| WARN(!list_empty(&mm->head_node.node_list), |
| 597,6 → 784,11 |
|---|
| 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; |
| 635,6 → 827,11 |
|---|
| 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; |