From 6bacb180cef00573fc41a1e79bdd5b89d6f1c1f5 Mon Sep 17 00:00:00 2001 From: Thomas Hellstrom Date: Tue, 6 Jun 2006 14:19:00 +0000 Subject: Merge in the drm-sman-branch --- linux-core/drm_mm.c | 201 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 201 insertions(+) create mode 100644 linux-core/drm_mm.c (limited to 'linux-core/drm_mm.c') diff --git a/linux-core/drm_mm.c b/linux-core/drm_mm.c new file mode 100644 index 00000000..a93760f9 --- /dev/null +++ b/linux-core/drm_mm.c @@ -0,0 +1,201 @@ +/************************************************************************** + * + * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND., USA. + * All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sub license, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice (including the + * next paragraph) shall be included in all copies or substantial portions + * of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL + * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, + * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR + * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE + * USE OR OTHER DEALINGS IN THE SOFTWARE. + * + * + **************************************************************************/ + +/* + * Generic simple memory manager implementation. Intended to be used as a base + * class implementation for more advanced memory managers. + * + * Note that the algorithm used is quite simple and there might be substantial + * performance gains if a smarter free list is implemented. Currently it is just an + * unordered stack of free regions. This could easily be improved if an RB-tree + * is used instead. At least if we expect heavy fragmentation. + * + * Aligned allocations can also see improvement. + * + * Authors: + * Thomas Hellström + */ + +#include "drmP.h" + +drm_mm_node_t *drm_mm_get_block(drm_mm_node_t * parent, + unsigned long size, unsigned alignment) +{ + + drm_mm_node_t *child; + + if (alignment) + size += alignment - 1; + + if (parent->size == size) { + list_del_init(&parent->fl_entry); + parent->free = FALSE; + return parent; + } else { + child = (drm_mm_node_t *) drm_alloc(sizeof(*child), DRM_MEM_MM); + if (!child) + return NULL; + + INIT_LIST_HEAD(&child->ml_entry); + INIT_LIST_HEAD(&child->fl_entry); + + child->free = FALSE; + child->size = size; + child->start = parent->start; + + list_add_tail(&child->ml_entry, &parent->ml_entry); + parent->size -= size; + parent->start += size; + } + return child; +} + +/* + * Put a block. Merge with the previous and / or next block if they are free. + * Otherwise add to the free stack. + */ + +void drm_mm_put_block(drm_mm_t * mm, drm_mm_node_t * cur) +{ + + drm_mm_node_t *list_root = &mm->root_node; + struct list_head *cur_head = &cur->ml_entry; + struct list_head *root_head = &list_root->ml_entry; + drm_mm_node_t *prev_node = NULL; + drm_mm_node_t *next_node; + + int merged = FALSE; + + if (cur_head->prev != root_head) { + prev_node = list_entry(cur_head->prev, drm_mm_node_t, ml_entry); + if (prev_node->free) { + prev_node->size += cur->size; + merged = TRUE; + } + } + if (cur_head->next != root_head) { + next_node = list_entry(cur_head->next, drm_mm_node_t, ml_entry); + if (next_node->free) { + if (merged) { + prev_node->size += next_node->size; + list_del(&next_node->ml_entry); + list_del(&next_node->fl_entry); + drm_free(next_node, sizeof(*next_node), + DRM_MEM_MM); + } else { + next_node->size += cur->size; + next_node->start = cur->start; + merged = TRUE; + } + } + } + if (!merged) { + cur->free = TRUE; + list_add(&cur->fl_entry, &list_root->fl_entry); + } else { + list_del(&cur->ml_entry); + drm_free(cur, sizeof(*cur), DRM_MEM_MM); + } +} + +drm_mm_node_t *drm_mm_search_free(const drm_mm_t * mm, + unsigned long size, + unsigned alignment, int best_match) +{ + struct list_head *list; + const struct list_head *free_stack = &mm->root_node.fl_entry; + drm_mm_node_t *entry; + drm_mm_node_t *best; + unsigned long best_size; + + best = NULL; + best_size = ~0UL; + + if (alignment) + size += alignment - 1; + + list_for_each(list, free_stack) { + entry = list_entry(list, drm_mm_node_t, fl_entry); + if (entry->size >= size) { + if (!best_match) + return entry; + if (size < best_size) { + best = entry; + best_size = entry->size; + } + } + } + + return best; +} + +int drm_mm_init(drm_mm_t * mm, unsigned long start, unsigned long size) +{ + drm_mm_node_t *child; + + INIT_LIST_HEAD(&mm->root_node.ml_entry); + INIT_LIST_HEAD(&mm->root_node.fl_entry); + child = (drm_mm_node_t *) drm_alloc(sizeof(*child), DRM_MEM_MM); + if (!child) + return -ENOMEM; + + INIT_LIST_HEAD(&child->ml_entry); + INIT_LIST_HEAD(&child->fl_entry); + + child->start = start; + child->size = size; + child->free = TRUE; + + list_add(&child->fl_entry, &mm->root_node.fl_entry); + list_add(&child->ml_entry, &mm->root_node.ml_entry); + + return 0; +} + +EXPORT_SYMBOL(drm_mm_init); + +void drm_mm_takedown(drm_mm_t * mm) +{ + struct list_head *bnode = mm->root_node.fl_entry.next; + drm_mm_node_t *entry; + + entry = list_entry(bnode, drm_mm_node_t, fl_entry); + + if (entry->ml_entry.next != &mm->root_node.ml_entry || + entry->fl_entry.next != &mm->root_node.fl_entry) { + DRM_ERROR("Memory manager not clean. Delaying takedown\n"); + return; + } + + list_del(&entry->fl_entry); + list_del(&entry->ml_entry); + + drm_free(entry, sizeof(*entry), DRM_MEM_MM); +} + +EXPORT_SYMBOL(drm_mm_takedown); -- cgit v1.2.3