621 lines
15 KiB
C
621 lines
15 KiB
C
/**************************************************************************
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*
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* Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND., USA.
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* All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sub license, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice (including the
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* next paragraph) shall be included in all copies or substantial portions
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* of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
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* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
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* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
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* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
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* USE OR OTHER DEALINGS IN THE SOFTWARE.
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*
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*
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**************************************************************************/
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/*
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* Generic simple memory manager implementation. Intended to be used as a base
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* class implementation for more advanced memory managers.
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*
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* Note that the algorithm used is quite simple and there might be substantial
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* performance gains if a smarter free list is implemented. Currently it is just an
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* unordered stack of free regions. This could easily be improved if an RB-tree
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* is used instead. At least if we expect heavy fragmentation.
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*
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* Aligned allocations can also see improvement.
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*
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* Authors:
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* Thomas Hellström <thomas-at-tungstengraphics-dot-com>
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*/
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#include "drmP.h"
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#include "drm_mm.h"
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#include <linux/slab.h>
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#include <linux/seq_file.h>
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#define MM_UNUSED_TARGET 4
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static struct drm_mm_node *drm_mm_kmalloc(struct drm_mm *mm, int atomic)
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{
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struct drm_mm_node *child;
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if (atomic)
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child = kzalloc(sizeof(*child), GFP_ATOMIC);
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else
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child = kzalloc(sizeof(*child), GFP_KERNEL);
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if (unlikely(child == NULL)) {
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spin_lock(&mm->unused_lock);
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if (list_empty(&mm->unused_nodes))
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child = NULL;
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else {
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child =
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list_entry(mm->unused_nodes.next,
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struct drm_mm_node, free_stack);
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list_del(&child->free_stack);
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--mm->num_unused;
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}
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spin_unlock(&mm->unused_lock);
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}
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return child;
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}
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/* drm_mm_pre_get() - pre allocate drm_mm_node structure
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* drm_mm: memory manager struct we are pre-allocating for
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*
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* Returns 0 on success or -ENOMEM if allocation fails.
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*/
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int drm_mm_pre_get(struct drm_mm *mm)
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{
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struct drm_mm_node *node;
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spin_lock(&mm->unused_lock);
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while (mm->num_unused < MM_UNUSED_TARGET) {
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spin_unlock(&mm->unused_lock);
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node = kzalloc(sizeof(*node), GFP_KERNEL);
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spin_lock(&mm->unused_lock);
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if (unlikely(node == NULL)) {
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int ret = (mm->num_unused < 2) ? -ENOMEM : 0;
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spin_unlock(&mm->unused_lock);
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return ret;
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}
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++mm->num_unused;
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list_add_tail(&node->free_stack, &mm->unused_nodes);
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}
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spin_unlock(&mm->unused_lock);
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return 0;
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}
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EXPORT_SYMBOL(drm_mm_pre_get);
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static int drm_mm_create_tail_node(struct drm_mm *mm,
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unsigned long start,
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unsigned long size, int atomic)
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{
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struct drm_mm_node *child;
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child = drm_mm_kmalloc(mm, atomic);
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if (unlikely(child == NULL))
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return -ENOMEM;
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child->free = 1;
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child->size = size;
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child->start = start;
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child->mm = mm;
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list_add_tail(&child->node_list, &mm->node_list);
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list_add_tail(&child->free_stack, &mm->free_stack);
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return 0;
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}
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static struct drm_mm_node *drm_mm_split_at_start(struct drm_mm_node *parent,
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unsigned long size,
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int atomic)
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{
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struct drm_mm_node *child;
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child = drm_mm_kmalloc(parent->mm, atomic);
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if (unlikely(child == NULL))
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return NULL;
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INIT_LIST_HEAD(&child->free_stack);
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child->size = size;
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child->start = parent->start;
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child->mm = parent->mm;
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list_add_tail(&child->node_list, &parent->node_list);
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INIT_LIST_HEAD(&child->free_stack);
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parent->size -= size;
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parent->start += size;
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return child;
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}
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struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *node,
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unsigned long size,
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unsigned alignment,
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int atomic)
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{
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struct drm_mm_node *align_splitoff = NULL;
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unsigned tmp = 0;
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if (alignment)
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tmp = node->start % alignment;
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if (tmp) {
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align_splitoff =
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drm_mm_split_at_start(node, alignment - tmp, atomic);
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if (unlikely(align_splitoff == NULL))
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return NULL;
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}
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if (node->size == size) {
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list_del_init(&node->free_stack);
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node->free = 0;
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} else {
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node = drm_mm_split_at_start(node, size, atomic);
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}
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if (align_splitoff)
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drm_mm_put_block(align_splitoff);
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return node;
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}
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EXPORT_SYMBOL(drm_mm_get_block_generic);
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struct drm_mm_node *drm_mm_get_block_range_generic(struct drm_mm_node *node,
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unsigned long size,
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unsigned alignment,
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unsigned long start,
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unsigned long end,
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int atomic)
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{
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struct drm_mm_node *align_splitoff = NULL;
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unsigned tmp = 0;
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unsigned wasted = 0;
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if (node->start < start)
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wasted += start - node->start;
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if (alignment)
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tmp = ((node->start + wasted) % alignment);
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if (tmp)
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wasted += alignment - tmp;
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if (wasted) {
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align_splitoff = drm_mm_split_at_start(node, wasted, atomic);
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if (unlikely(align_splitoff == NULL))
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return NULL;
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}
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if (node->size == size) {
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list_del_init(&node->free_stack);
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node->free = 0;
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} else {
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node = drm_mm_split_at_start(node, size, atomic);
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}
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if (align_splitoff)
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drm_mm_put_block(align_splitoff);
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return node;
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}
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EXPORT_SYMBOL(drm_mm_get_block_range_generic);
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/*
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* Put a block. Merge with the previous and / or next block if they are free.
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* Otherwise add to the free stack.
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*/
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void drm_mm_put_block(struct drm_mm_node *cur)
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{
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struct drm_mm *mm = cur->mm;
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struct list_head *cur_head = &cur->node_list;
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struct list_head *root_head = &mm->node_list;
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struct drm_mm_node *prev_node = NULL;
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struct drm_mm_node *next_node;
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int merged = 0;
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BUG_ON(cur->scanned_block || cur->scanned_prev_free
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|| cur->scanned_next_free);
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if (cur_head->prev != root_head) {
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prev_node =
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list_entry(cur_head->prev, struct drm_mm_node, node_list);
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if (prev_node->free) {
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prev_node->size += cur->size;
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merged = 1;
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}
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}
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if (cur_head->next != root_head) {
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next_node =
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list_entry(cur_head->next, struct drm_mm_node, node_list);
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if (next_node->free) {
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if (merged) {
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prev_node->size += next_node->size;
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list_del(&next_node->node_list);
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list_del(&next_node->free_stack);
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spin_lock(&mm->unused_lock);
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if (mm->num_unused < MM_UNUSED_TARGET) {
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list_add(&next_node->free_stack,
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&mm->unused_nodes);
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++mm->num_unused;
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} else
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kfree(next_node);
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spin_unlock(&mm->unused_lock);
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} else {
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next_node->size += cur->size;
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next_node->start = cur->start;
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merged = 1;
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}
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}
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}
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if (!merged) {
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cur->free = 1;
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list_add(&cur->free_stack, &mm->free_stack);
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} else {
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list_del(&cur->node_list);
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spin_lock(&mm->unused_lock);
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if (mm->num_unused < MM_UNUSED_TARGET) {
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list_add(&cur->free_stack, &mm->unused_nodes);
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++mm->num_unused;
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} else
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kfree(cur);
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spin_unlock(&mm->unused_lock);
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}
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}
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EXPORT_SYMBOL(drm_mm_put_block);
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static int check_free_hole(unsigned long start, unsigned long end,
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unsigned long size, unsigned alignment)
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{
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unsigned wasted = 0;
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if (end - start < size)
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return 0;
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if (alignment) {
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unsigned tmp = start % alignment;
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if (tmp)
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wasted = alignment - tmp;
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}
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if (end >= start + size + wasted) {
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return 1;
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}
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return 0;
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}
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struct drm_mm_node *drm_mm_search_free(const struct drm_mm *mm,
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unsigned long size,
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unsigned alignment, int best_match)
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{
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struct drm_mm_node *entry;
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struct drm_mm_node *best;
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unsigned long best_size;
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BUG_ON(mm->scanned_blocks);
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best = NULL;
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best_size = ~0UL;
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list_for_each_entry(entry, &mm->free_stack, free_stack) {
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if (!check_free_hole(entry->start, entry->start + entry->size,
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size, alignment))
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continue;
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if (!best_match)
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return entry;
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if (entry->size < best_size) {
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best = entry;
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best_size = entry->size;
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}
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}
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return best;
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}
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EXPORT_SYMBOL(drm_mm_search_free);
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struct drm_mm_node *drm_mm_search_free_in_range(const struct drm_mm *mm,
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unsigned long size,
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unsigned alignment,
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unsigned long start,
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unsigned long end,
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int best_match)
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{
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struct drm_mm_node *entry;
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struct drm_mm_node *best;
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unsigned long best_size;
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BUG_ON(mm->scanned_blocks);
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best = NULL;
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best_size = ~0UL;
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list_for_each_entry(entry, &mm->free_stack, free_stack) {
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unsigned long adj_start = entry->start < start ?
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start : entry->start;
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unsigned long adj_end = entry->start + entry->size > end ?
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end : entry->start + entry->size;
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if (!check_free_hole(adj_start, adj_end, size, alignment))
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continue;
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if (!best_match)
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return entry;
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if (entry->size < best_size) {
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best = entry;
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best_size = entry->size;
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}
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}
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return best;
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}
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EXPORT_SYMBOL(drm_mm_search_free_in_range);
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/**
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* Initializa lru scanning.
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*
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* This simply sets up the scanning routines with the parameters for the desired
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* hole.
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*
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* Warning: As long as the scan list is non-empty, no other operations than
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* adding/removing nodes to/from the scan list are allowed.
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*/
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void drm_mm_init_scan(struct drm_mm *mm, unsigned long size,
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unsigned alignment)
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{
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mm->scan_alignment = alignment;
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mm->scan_size = size;
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mm->scanned_blocks = 0;
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mm->scan_hit_start = 0;
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mm->scan_hit_size = 0;
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}
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EXPORT_SYMBOL(drm_mm_init_scan);
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/**
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* Add a node to the scan list that might be freed to make space for the desired
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* hole.
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*
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* Returns non-zero, if a hole has been found, zero otherwise.
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*/
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int drm_mm_scan_add_block(struct drm_mm_node *node)
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{
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struct drm_mm *mm = node->mm;
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struct list_head *prev_free, *next_free;
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struct drm_mm_node *prev_node, *next_node;
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mm->scanned_blocks++;
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prev_free = next_free = NULL;
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BUG_ON(node->free);
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node->scanned_block = 1;
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node->free = 1;
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if (node->node_list.prev != &mm->node_list) {
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prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
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node_list);
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if (prev_node->free) {
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list_del(&prev_node->node_list);
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node->start = prev_node->start;
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node->size += prev_node->size;
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prev_node->scanned_prev_free = 1;
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prev_free = &prev_node->free_stack;
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}
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}
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if (node->node_list.next != &mm->node_list) {
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next_node = list_entry(node->node_list.next, struct drm_mm_node,
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node_list);
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if (next_node->free) {
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list_del(&next_node->node_list);
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node->size += next_node->size;
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next_node->scanned_next_free = 1;
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next_free = &next_node->free_stack;
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}
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}
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/* The free_stack list is not used for allocated objects, so these two
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* pointers can be abused (as long as no allocations in this memory
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* manager happens). */
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node->free_stack.prev = prev_free;
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node->free_stack.next = next_free;
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if (check_free_hole(node->start, node->start + node->size,
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mm->scan_size, mm->scan_alignment)) {
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mm->scan_hit_start = node->start;
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mm->scan_hit_size = node->size;
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return 1;
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}
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return 0;
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}
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EXPORT_SYMBOL(drm_mm_scan_add_block);
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/**
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* Remove a node from the scan list.
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*
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* Nodes _must_ be removed in the exact same order from the scan list as they
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* have been added, otherwise the internal state of the memory manager will be
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* corrupted.
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*
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* When the scan list is empty, the selected memory nodes can be freed. An
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* immediatly following drm_mm_search_free with best_match = 0 will then return
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* the just freed block (because its at the top of the free_stack list).
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*
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* Returns one if this block should be evicted, zero otherwise. Will always
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* return zero when no hole has been found.
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*/
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int drm_mm_scan_remove_block(struct drm_mm_node *node)
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{
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struct drm_mm *mm = node->mm;
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struct drm_mm_node *prev_node, *next_node;
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mm->scanned_blocks--;
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BUG_ON(!node->scanned_block);
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node->scanned_block = 0;
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node->free = 0;
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prev_node = list_entry(node->free_stack.prev, struct drm_mm_node,
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free_stack);
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next_node = list_entry(node->free_stack.next, struct drm_mm_node,
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free_stack);
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if (prev_node) {
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BUG_ON(!prev_node->scanned_prev_free);
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prev_node->scanned_prev_free = 0;
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list_add_tail(&prev_node->node_list, &node->node_list);
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node->start = prev_node->start + prev_node->size;
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node->size -= prev_node->size;
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}
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if (next_node) {
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BUG_ON(!next_node->scanned_next_free);
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next_node->scanned_next_free = 0;
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list_add(&next_node->node_list, &node->node_list);
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node->size -= next_node->size;
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}
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INIT_LIST_HEAD(&node->free_stack);
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/* Only need to check for containement because start&size for the
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* complete resulting free block (not just the desired part) is
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* stored. */
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if (node->start >= mm->scan_hit_start &&
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node->start + node->size
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<= mm->scan_hit_start + mm->scan_hit_size) {
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return 1;
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}
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return 0;
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}
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EXPORT_SYMBOL(drm_mm_scan_remove_block);
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int drm_mm_clean(struct drm_mm * mm)
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{
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struct list_head *head = &mm->node_list;
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return (head->next->next == head);
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}
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EXPORT_SYMBOL(drm_mm_clean);
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int drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
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{
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INIT_LIST_HEAD(&mm->node_list);
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INIT_LIST_HEAD(&mm->free_stack);
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INIT_LIST_HEAD(&mm->unused_nodes);
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mm->num_unused = 0;
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mm->scanned_blocks = 0;
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spin_lock_init(&mm->unused_lock);
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return drm_mm_create_tail_node(mm, start, size, 0);
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}
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EXPORT_SYMBOL(drm_mm_init);
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void drm_mm_takedown(struct drm_mm * mm)
|
|
{
|
|
struct list_head *bnode = mm->free_stack.next;
|
|
struct drm_mm_node *entry;
|
|
struct drm_mm_node *next;
|
|
|
|
entry = list_entry(bnode, struct drm_mm_node, free_stack);
|
|
|
|
if (entry->node_list.next != &mm->node_list ||
|
|
entry->free_stack.next != &mm->free_stack) {
|
|
DRM_ERROR("Memory manager not clean. Delaying takedown\n");
|
|
return;
|
|
}
|
|
|
|
list_del(&entry->free_stack);
|
|
list_del(&entry->node_list);
|
|
kfree(entry);
|
|
|
|
spin_lock(&mm->unused_lock);
|
|
list_for_each_entry_safe(entry, next, &mm->unused_nodes, free_stack) {
|
|
list_del(&entry->free_stack);
|
|
kfree(entry);
|
|
--mm->num_unused;
|
|
}
|
|
spin_unlock(&mm->unused_lock);
|
|
|
|
BUG_ON(mm->num_unused != 0);
|
|
}
|
|
EXPORT_SYMBOL(drm_mm_takedown);
|
|
|
|
void drm_mm_debug_table(struct drm_mm *mm, const char *prefix)
|
|
{
|
|
struct drm_mm_node *entry;
|
|
int total_used = 0, total_free = 0, total = 0;
|
|
|
|
list_for_each_entry(entry, &mm->node_list, node_list) {
|
|
printk(KERN_DEBUG "%s 0x%08lx-0x%08lx: %8ld: %s\n",
|
|
prefix, entry->start, entry->start + entry->size,
|
|
entry->size, entry->free ? "free" : "used");
|
|
total += entry->size;
|
|
if (entry->free)
|
|
total_free += entry->size;
|
|
else
|
|
total_used += entry->size;
|
|
}
|
|
printk(KERN_DEBUG "%s total: %d, used %d free %d\n", prefix, total,
|
|
total_used, total_free);
|
|
}
|
|
EXPORT_SYMBOL(drm_mm_debug_table);
|
|
|
|
#if defined(CONFIG_DEBUG_FS)
|
|
int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
|
|
{
|
|
struct drm_mm_node *entry;
|
|
int total_used = 0, total_free = 0, total = 0;
|
|
|
|
list_for_each_entry(entry, &mm->node_list, node_list) {
|
|
seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: %s\n", entry->start, entry->start + entry->size, entry->size, entry->free ? "free" : "used");
|
|
total += entry->size;
|
|
if (entry->free)
|
|
total_free += entry->size;
|
|
else
|
|
total_used += entry->size;
|
|
}
|
|
seq_printf(m, "total: %d, used %d free %d\n", total, total_used, total_free);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(drm_mm_dump_table);
|
|
#endif
|