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author | David S. Miller <davem@davemloft.net> | 2008-07-18 02:39:39 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2008-07-18 02:39:39 -0700 |
commit | 49997d75152b3d23c53b0fa730599f2f74c92c65 (patch) | |
tree | 46e93126170d02cfec9505172e545732c1b69656 /drivers/gpu/drm/drm_mm.c | |
parent | a0c80b80e0fb48129e4e9d6a9ede914f9ff1850d (diff) | |
parent | 5b664cb235e97afbf34db9c4d77f08ebd725335e (diff) | |
download | blackbird-op-linux-49997d75152b3d23c53b0fa730599f2f74c92c65.tar.gz blackbird-op-linux-49997d75152b3d23c53b0fa730599f2f74c92c65.zip |
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts:
Documentation/powerpc/booting-without-of.txt
drivers/atm/Makefile
drivers/net/fs_enet/fs_enet-main.c
drivers/pci/pci-acpi.c
net/8021q/vlan.c
net/iucv/iucv.c
Diffstat (limited to 'drivers/gpu/drm/drm_mm.c')
-rw-r--r-- | drivers/gpu/drm/drm_mm.c | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c new file mode 100644 index 000000000000..dcff9e9b52e3 --- /dev/null +++ b/drivers/gpu/drm/drm_mm.c @@ -0,0 +1,295 @@ +/************************************************************************** + * + * 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 <thomas-at-tungstengraphics-dot-com> + */ + +#include "drmP.h" +#include <linux/slab.h> + +unsigned long drm_mm_tail_space(struct drm_mm *mm) +{ + struct list_head *tail_node; + struct drm_mm_node *entry; + + tail_node = mm->ml_entry.prev; + entry = list_entry(tail_node, struct drm_mm_node, ml_entry); + if (!entry->free) + return 0; + + return entry->size; +} + +int drm_mm_remove_space_from_tail(struct drm_mm *mm, unsigned long size) +{ + struct list_head *tail_node; + struct drm_mm_node *entry; + + tail_node = mm->ml_entry.prev; + entry = list_entry(tail_node, struct drm_mm_node, ml_entry); + if (!entry->free) + return -ENOMEM; + + if (entry->size <= size) + return -ENOMEM; + + entry->size -= size; + return 0; +} + + +static int drm_mm_create_tail_node(struct drm_mm *mm, + unsigned long start, + unsigned long size) +{ + struct drm_mm_node *child; + + child = (struct drm_mm_node *) + drm_alloc(sizeof(*child), DRM_MEM_MM); + if (!child) + return -ENOMEM; + + child->free = 1; + child->size = size; + child->start = start; + child->mm = mm; + + list_add_tail(&child->ml_entry, &mm->ml_entry); + list_add_tail(&child->fl_entry, &mm->fl_entry); + + return 0; +} + + +int drm_mm_add_space_to_tail(struct drm_mm *mm, unsigned long size) +{ + struct list_head *tail_node; + struct drm_mm_node *entry; + + tail_node = mm->ml_entry.prev; + entry = list_entry(tail_node, struct drm_mm_node, ml_entry); + if (!entry->free) { + return drm_mm_create_tail_node(mm, entry->start + entry->size, size); + } + entry->size += size; + return 0; +} + +static struct drm_mm_node *drm_mm_split_at_start(struct drm_mm_node *parent, + unsigned long size) +{ + struct drm_mm_node *child; + + child = (struct drm_mm_node *) + drm_alloc(sizeof(*child), DRM_MEM_MM); + if (!child) + return NULL; + + INIT_LIST_HEAD(&child->fl_entry); + + child->free = 0; + child->size = size; + child->start = parent->start; + child->mm = parent->mm; + + list_add_tail(&child->ml_entry, &parent->ml_entry); + INIT_LIST_HEAD(&child->fl_entry); + + parent->size -= size; + parent->start += size; + return child; +} + + + +struct drm_mm_node *drm_mm_get_block(struct drm_mm_node * parent, + unsigned long size, unsigned alignment) +{ + + struct drm_mm_node *align_splitoff = NULL; + struct drm_mm_node *child; + unsigned tmp = 0; + + if (alignment) + tmp = parent->start % alignment; + + if (tmp) { + align_splitoff = drm_mm_split_at_start(parent, alignment - tmp); + if (!align_splitoff) + return NULL; + } + + if (parent->size == size) { + list_del_init(&parent->fl_entry); + parent->free = 0; + return parent; + } else { + child = drm_mm_split_at_start(parent, size); + } + + if (align_splitoff) + drm_mm_put_block(align_splitoff); + + 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(struct drm_mm_node * cur) +{ + + struct drm_mm *mm = cur->mm; + struct list_head *cur_head = &cur->ml_entry; + struct list_head *root_head = &mm->ml_entry; + struct drm_mm_node *prev_node = NULL; + struct drm_mm_node *next_node; + + int merged = 0; + + if (cur_head->prev != root_head) { + prev_node = list_entry(cur_head->prev, struct drm_mm_node, ml_entry); + if (prev_node->free) { + prev_node->size += cur->size; + merged = 1; + } + } + if (cur_head->next != root_head) { + next_node = list_entry(cur_head->next, struct drm_mm_node, 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 = 1; + } + } + } + if (!merged) { + cur->free = 1; + list_add(&cur->fl_entry, &mm->fl_entry); + } else { + list_del(&cur->ml_entry); + drm_free(cur, sizeof(*cur), DRM_MEM_MM); + } +} + +struct drm_mm_node *drm_mm_search_free(const struct drm_mm * mm, + unsigned long size, + unsigned alignment, int best_match) +{ + struct list_head *list; + const struct list_head *free_stack = &mm->fl_entry; + struct drm_mm_node *entry; + struct drm_mm_node *best; + unsigned long best_size; + unsigned wasted; + + best = NULL; + best_size = ~0UL; + + list_for_each(list, free_stack) { + entry = list_entry(list, struct drm_mm_node, fl_entry); + wasted = 0; + + if (entry->size < size) + continue; + + if (alignment) { + register unsigned tmp = entry->start % alignment; + if (tmp) + wasted += alignment - tmp; + } + + + if (entry->size >= size + wasted) { + if (!best_match) + return entry; + if (size < best_size) { + best = entry; + best_size = entry->size; + } + } + } + + return best; +} + +int drm_mm_clean(struct drm_mm * mm) +{ + struct list_head *head = &mm->ml_entry; + + return (head->next->next == head); +} + +int drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size) +{ + INIT_LIST_HEAD(&mm->ml_entry); + INIT_LIST_HEAD(&mm->fl_entry); + + return drm_mm_create_tail_node(mm, start, size); +} + + +void drm_mm_takedown(struct drm_mm * mm) +{ + struct list_head *bnode = mm->fl_entry.next; + struct drm_mm_node *entry; + + entry = list_entry(bnode, struct drm_mm_node, fl_entry); + + if (entry->ml_entry.next != &mm->ml_entry || + entry->fl_entry.next != &mm->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); +} |