linux/drivers/gpu/drm/drm_mm.c
Daniel Vetter 7521473305 drm: mm: fix range restricted allocations
With the code cleanup in

7a6b2896f2 is the first bad commit
commit 7a6b2896f2
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Jul 2 15:02:15 2010 +0100

    drm_mm: extract check_free_mm_node

I've botched up the range-restriction checks. The result is usually
an X server dying with SIGBUS in libpixman (software fallback rendering).
Change the code to adjust the start and end for range restricted
allocations. IMHO this even makes the code a bit clearer.

Fixes regression bug: https://bugs.freedesktop.org/show_bug.cgi?id=29738

Reported-by-Tested-by: Till MAtthiesen <entropy@everymail.net>
Acked-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-08-27 09:10:16 +10:00

621 lines
15 KiB
C

/**************************************************************************
*
* 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 "drm_mm.h"
#include <linux/slab.h>
#include <linux/seq_file.h>
#define MM_UNUSED_TARGET 4
static struct drm_mm_node *drm_mm_kmalloc(struct drm_mm *mm, int atomic)
{
struct drm_mm_node *child;
if (atomic)
child = kzalloc(sizeof(*child), GFP_ATOMIC);
else
child = kzalloc(sizeof(*child), GFP_KERNEL);
if (unlikely(child == NULL)) {
spin_lock(&mm->unused_lock);
if (list_empty(&mm->unused_nodes))
child = NULL;
else {
child =
list_entry(mm->unused_nodes.next,
struct drm_mm_node, free_stack);
list_del(&child->free_stack);
--mm->num_unused;
}
spin_unlock(&mm->unused_lock);
}
return child;
}
/* drm_mm_pre_get() - pre allocate drm_mm_node structure
* drm_mm: memory manager struct we are pre-allocating for
*
* Returns 0 on success or -ENOMEM if allocation fails.
*/
int drm_mm_pre_get(struct drm_mm *mm)
{
struct drm_mm_node *node;
spin_lock(&mm->unused_lock);
while (mm->num_unused < MM_UNUSED_TARGET) {
spin_unlock(&mm->unused_lock);
node = kzalloc(sizeof(*node), GFP_KERNEL);
spin_lock(&mm->unused_lock);
if (unlikely(node == NULL)) {
int ret = (mm->num_unused < 2) ? -ENOMEM : 0;
spin_unlock(&mm->unused_lock);
return ret;
}
++mm->num_unused;
list_add_tail(&node->free_stack, &mm->unused_nodes);
}
spin_unlock(&mm->unused_lock);
return 0;
}
EXPORT_SYMBOL(drm_mm_pre_get);
static int drm_mm_create_tail_node(struct drm_mm *mm,
unsigned long start,
unsigned long size, int atomic)
{
struct drm_mm_node *child;
child = drm_mm_kmalloc(mm, atomic);
if (unlikely(child == NULL))
return -ENOMEM;
child->free = 1;
child->size = size;
child->start = start;
child->mm = mm;
list_add_tail(&child->node_list, &mm->node_list);
list_add_tail(&child->free_stack, &mm->free_stack);
return 0;
}
static struct drm_mm_node *drm_mm_split_at_start(struct drm_mm_node *parent,
unsigned long size,
int atomic)
{
struct drm_mm_node *child;
child = drm_mm_kmalloc(parent->mm, atomic);
if (unlikely(child == NULL))
return NULL;
INIT_LIST_HEAD(&child->free_stack);
child->size = size;
child->start = parent->start;
child->mm = parent->mm;
list_add_tail(&child->node_list, &parent->node_list);
INIT_LIST_HEAD(&child->free_stack);
parent->size -= size;
parent->start += size;
return child;
}
struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *node,
unsigned long size,
unsigned alignment,
int atomic)
{
struct drm_mm_node *align_splitoff = NULL;
unsigned tmp = 0;
if (alignment)
tmp = node->start % alignment;
if (tmp) {
align_splitoff =
drm_mm_split_at_start(node, alignment - tmp, atomic);
if (unlikely(align_splitoff == NULL))
return NULL;
}
if (node->size == size) {
list_del_init(&node->free_stack);
node->free = 0;
} else {
node = drm_mm_split_at_start(node, size, atomic);
}
if (align_splitoff)
drm_mm_put_block(align_splitoff);
return node;
}
EXPORT_SYMBOL(drm_mm_get_block_generic);
struct drm_mm_node *drm_mm_get_block_range_generic(struct drm_mm_node *node,
unsigned long size,
unsigned alignment,
unsigned long start,
unsigned long end,
int atomic)
{
struct drm_mm_node *align_splitoff = NULL;
unsigned tmp = 0;
unsigned wasted = 0;
if (node->start < start)
wasted += start - node->start;
if (alignment)
tmp = ((node->start + wasted) % alignment);
if (tmp)
wasted += alignment - tmp;
if (wasted) {
align_splitoff = drm_mm_split_at_start(node, wasted, atomic);
if (unlikely(align_splitoff == NULL))
return NULL;
}
if (node->size == size) {
list_del_init(&node->free_stack);
node->free = 0;
} else {
node = drm_mm_split_at_start(node, size, atomic);
}
if (align_splitoff)
drm_mm_put_block(align_splitoff);
return node;
}
EXPORT_SYMBOL(drm_mm_get_block_range_generic);
/*
* 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->node_list;
struct list_head *root_head = &mm->node_list;
struct drm_mm_node *prev_node = NULL;
struct drm_mm_node *next_node;
int merged = 0;
BUG_ON(cur->scanned_block || cur->scanned_prev_free
|| cur->scanned_next_free);
if (cur_head->prev != root_head) {
prev_node =
list_entry(cur_head->prev, struct drm_mm_node, node_list);
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, node_list);
if (next_node->free) {
if (merged) {
prev_node->size += next_node->size;
list_del(&next_node->node_list);
list_del(&next_node->free_stack);
spin_lock(&mm->unused_lock);
if (mm->num_unused < MM_UNUSED_TARGET) {
list_add(&next_node->free_stack,
&mm->unused_nodes);
++mm->num_unused;
} else
kfree(next_node);
spin_unlock(&mm->unused_lock);
} else {
next_node->size += cur->size;
next_node->start = cur->start;
merged = 1;
}
}
}
if (!merged) {
cur->free = 1;
list_add(&cur->free_stack, &mm->free_stack);
} else {
list_del(&cur->node_list);
spin_lock(&mm->unused_lock);
if (mm->num_unused < MM_UNUSED_TARGET) {
list_add(&cur->free_stack, &mm->unused_nodes);
++mm->num_unused;
} else
kfree(cur);
spin_unlock(&mm->unused_lock);
}
}
EXPORT_SYMBOL(drm_mm_put_block);
static int check_free_hole(unsigned long start, unsigned long end,
unsigned long size, unsigned alignment)
{
unsigned wasted = 0;
if (end - start < size)
return 0;
if (alignment) {
unsigned tmp = start % alignment;
if (tmp)
wasted = alignment - tmp;
}
if (end >= start + size + wasted) {
return 1;
}
return 0;
}
struct drm_mm_node *drm_mm_search_free(const struct drm_mm *mm,
unsigned long size,
unsigned alignment, int best_match)
{
struct drm_mm_node *entry;
struct drm_mm_node *best;
unsigned long best_size;
BUG_ON(mm->scanned_blocks);
best = NULL;
best_size = ~0UL;
list_for_each_entry(entry, &mm->free_stack, free_stack) {
if (!check_free_hole(entry->start, entry->start + entry->size,
size, alignment))
continue;
if (!best_match)
return entry;
if (entry->size < best_size) {
best = entry;
best_size = entry->size;
}
}
return best;
}
EXPORT_SYMBOL(drm_mm_search_free);
struct drm_mm_node *drm_mm_search_free_in_range(const struct drm_mm *mm,
unsigned long size,
unsigned alignment,
unsigned long start,
unsigned long end,
int best_match)
{
struct drm_mm_node *entry;
struct drm_mm_node *best;
unsigned long best_size;
BUG_ON(mm->scanned_blocks);
best = NULL;
best_size = ~0UL;
list_for_each_entry(entry, &mm->free_stack, free_stack) {
unsigned long adj_start = entry->start < start ?
start : entry->start;
unsigned long adj_end = entry->start + entry->size > end ?
end : entry->start + entry->size;
if (!check_free_hole(adj_start, adj_end, size, alignment))
continue;
if (!best_match)
return entry;
if (entry->size < best_size) {
best = entry;
best_size = entry->size;
}
}
return best;
}
EXPORT_SYMBOL(drm_mm_search_free_in_range);
/**
* Initializa lru scanning.
*
* 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.
*/
void drm_mm_init_scan(struct drm_mm *mm, unsigned long size,
unsigned alignment)
{
mm->scan_alignment = alignment;
mm->scan_size = size;
mm->scanned_blocks = 0;
mm->scan_hit_start = 0;
mm->scan_hit_size = 0;
}
EXPORT_SYMBOL(drm_mm_init_scan);
/**
* 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.
*/
int drm_mm_scan_add_block(struct drm_mm_node *node)
{
struct drm_mm *mm = node->mm;
struct list_head *prev_free, *next_free;
struct drm_mm_node *prev_node, *next_node;
mm->scanned_blocks++;
prev_free = next_free = NULL;
BUG_ON(node->free);
node->scanned_block = 1;
node->free = 1;
if (node->node_list.prev != &mm->node_list) {
prev_node = list_entry(node->node_list.prev, struct drm_mm_node,
node_list);
if (prev_node->free) {
list_del(&prev_node->node_list);
node->start = prev_node->start;
node->size += prev_node->size;
prev_node->scanned_prev_free = 1;
prev_free = &prev_node->free_stack;
}
}
if (node->node_list.next != &mm->node_list) {
next_node = list_entry(node->node_list.next, struct drm_mm_node,
node_list);
if (next_node->free) {
list_del(&next_node->node_list);
node->size += next_node->size;
next_node->scanned_next_free = 1;
next_free = &next_node->free_stack;
}
}
/* The free_stack list is not used for allocated objects, so these two
* pointers can be abused (as long as no allocations in this memory
* manager happens). */
node->free_stack.prev = prev_free;
node->free_stack.next = next_free;
if (check_free_hole(node->start, node->start + node->size,
mm->scan_size, mm->scan_alignment)) {
mm->scan_hit_start = node->start;
mm->scan_hit_size = node->size;
return 1;
}
return 0;
}
EXPORT_SYMBOL(drm_mm_scan_add_block);
/**
* Remove a node from the scan list.
*
* 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
* corrupted.
*
* When the scan list is empty, the selected memory nodes can be freed. An
* immediatly following drm_mm_search_free with best_match = 0 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.
*/
int drm_mm_scan_remove_block(struct drm_mm_node *node)
{
struct drm_mm *mm = node->mm;
struct drm_mm_node *prev_node, *next_node;
mm->scanned_blocks--;
BUG_ON(!node->scanned_block);
node->scanned_block = 0;
node->free = 0;
prev_node = list_entry(node->free_stack.prev, struct drm_mm_node,
free_stack);
next_node = list_entry(node->free_stack.next, struct drm_mm_node,
free_stack);
if (prev_node) {
BUG_ON(!prev_node->scanned_prev_free);
prev_node->scanned_prev_free = 0;
list_add_tail(&prev_node->node_list, &node->node_list);
node->start = prev_node->start + prev_node->size;
node->size -= prev_node->size;
}
if (next_node) {
BUG_ON(!next_node->scanned_next_free);
next_node->scanned_next_free = 0;
list_add(&next_node->node_list, &node->node_list);
node->size -= next_node->size;
}
INIT_LIST_HEAD(&node->free_stack);
/* Only need to check for containement because start&size for the
* complete resulting free block (not just the desired part) is
* stored. */
if (node->start >= mm->scan_hit_start &&
node->start + node->size
<= mm->scan_hit_start + mm->scan_hit_size) {
return 1;
}
return 0;
}
EXPORT_SYMBOL(drm_mm_scan_remove_block);
int drm_mm_clean(struct drm_mm * mm)
{
struct list_head *head = &mm->node_list;
return (head->next->next == head);
}
EXPORT_SYMBOL(drm_mm_clean);
int drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
{
INIT_LIST_HEAD(&mm->node_list);
INIT_LIST_HEAD(&mm->free_stack);
INIT_LIST_HEAD(&mm->unused_nodes);
mm->num_unused = 0;
mm->scanned_blocks = 0;
spin_lock_init(&mm->unused_lock);
return drm_mm_create_tail_node(mm, start, size, 0);
}
EXPORT_SYMBOL(drm_mm_init);
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