1 files changed, 297 insertions, 0 deletions
diff --git a/linux-core/drm_memrange.c b/linux-core/drm_memrange.c
new file mode 100644
index 00000000..5921eff8
--- /dev/null
+++ b/linux-core/drm_memrange.c
@@ -0,0 +1,297 @@
+/**************************************************************************
+ *
+ * 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_memrange_tail_space(struct drm_memrange *mm)
+{
+	struct list_head *tail_node;
+	struct drm_memrange_node *entry;
+
+	tail_node = mm->ml_entry.prev;
+	entry = list_entry(tail_node, struct drm_memrange_node, ml_entry);
+	if (!entry->free)
+		return 0;
+
+	return entry->size;
+}
+
+int drm_memrange_remove_space_from_tail(struct drm_memrange *mm, unsigned long size)
+{
+	struct list_head *tail_node;
+	struct drm_memrange_node *entry;
+
+	tail_node = mm->ml_entry.prev;
+	entry = list_entry(tail_node, struct drm_memrange_node, ml_entry);
+	if (!entry->free)
+		return -ENOMEM;
+
+	if (entry->size <= size)
+		return -ENOMEM;
+
+	entry->size -= size;
+	return 0;
+}
+
+
+static int drm_memrange_create_tail_node(struct drm_memrange *mm,
+			    unsigned long start,
+			    unsigned long size)
+{
+	struct drm_memrange_node *child;
+
+	child = (struct drm_memrange_node *)
+		drm_ctl_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_memrange_add_space_to_tail(struct drm_memrange *mm, unsigned long size)
+{
+	struct list_head *tail_node;
+	struct drm_memrange_node *entry;
+
+	tail_node = mm->ml_entry.prev;
+	entry = list_entry(tail_node, struct drm_memrange_node, ml_entry);
+	if (!entry->free) {
+		return drm_memrange_create_tail_node(mm, entry->start + entry->size, size);
+	}
+	entry->size += size;
+	return 0;
+}
+
+static struct drm_memrange_node *drm_memrange_split_at_start(struct drm_memrange_node *parent,
+					    unsigned long size)
+{
+	struct drm_memrange_node *child;
+
+	child = (struct drm_memrange_node *)
+		drm_ctl_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_memrange_node *drm_memrange_get_block(struct drm_memrange_node * parent,
+				unsigned long size, unsigned alignment)
+{
+
+	struct drm_memrange_node *align_splitoff = NULL;
+	struct drm_memrange_node *child;
+	unsigned tmp = 0;
+
+	if (alignment)
+		tmp = parent->start % alignment;
+
+	if (tmp) {
+		align_splitoff = drm_memrange_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_memrange_split_at_start(parent, size);
+	}
+
+	if (align_splitoff)
+		drm_memrange_put_block(align_splitoff);
+
+	return child;
+}
+EXPORT_SYMBOL(drm_memrange_get_block);
+
+/*
+ * Put a block. Merge with the previous and / or next block if they are free.
+ * Otherwise add to the free stack.
+ */
+
+void drm_memrange_put_block(struct drm_memrange_node * cur)
+{
+
+	struct drm_memrange *mm = cur->mm;
+	struct list_head *cur_head = &cur->ml_entry;
+	struct list_head *root_head = &mm->ml_entry;
+	struct drm_memrange_node *prev_node = NULL;
+	struct drm_memrange_node *next_node;
+
+	int merged = 0;
+
+	if (cur_head->prev != root_head) {
+		prev_node = list_entry(cur_head->prev, struct drm_memrange_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_memrange_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_ctl_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_ctl_free(cur, sizeof(*cur), DRM_MEM_MM);
+	}
+}
+EXPORT_SYMBOL(drm_memrange_put_block);
+
+struct drm_memrange_node *drm_memrange_search_free(const struct drm_memrange * mm,
+				  unsigned long size,
+				  unsigned alignment, int best_match)
+{
+	struct list_head *list;
+	const struct list_head *free_stack = &mm->fl_entry;
+	struct drm_memrange_node *entry;
+	struct drm_memrange_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_memrange_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;
+}
+EXPORT_SYMBOL(drm_memrange_search_free);
+
+int drm_memrange_clean(struct drm_memrange * mm)
+{
+	struct list_head *head = &mm->ml_entry;
+
+	return (head->next->next == head);
+}
+
+int drm_memrange_init(struct drm_memrange * mm, unsigned long start, unsigned long size)
+{
+	INIT_LIST_HEAD(&mm->ml_entry);
+	INIT_LIST_HEAD(&mm->fl_entry);
+
+	return drm_memrange_create_tail_node(mm, start, size);
+}
+
+EXPORT_SYMBOL(drm_memrange_init);
+
+void drm_memrange_takedown(struct drm_memrange * mm)
+{
+	struct list_head *bnode = mm->fl_entry.next;
+	struct drm_memrange_node *entry;
+
+	entry = list_entry(bnode, struct drm_memrange_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_ctl_free(entry, sizeof(*entry), DRM_MEM_MM);
+}
+EXPORT_SYMBOL(drm_memrange_takedown);