drm: Split out the mm declarations in a separate header. Add atomic operations.

this is a TTM preparation patch, it rearranges the mm and
add operations needed to do mm operations in atomic context.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 137 insertions, 28 deletions

diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
index 367c590ffbba..7819fd930a51 100644
--- a/drivers/gpu/drm/drm_mm.c
+++ b/drivers/gpu/drm/drm_mm.c
@@ -42,8 +42,11 @@
  */
 
 #include "drmP.h"
+#include "drm_mm.h"
 #include <linux/slab.h>
 
+#define MM_UNUSED_TARGET 4
+
 unsigned long drm_mm_tail_space(struct drm_mm *mm)
 {
         struct list_head *tail_node;
@@ -74,16 +77,62 @@ int drm_mm_remove_space_from_tail(struct drm_mm *mm, unsigned long size)
         return 0;
 }
 
+static struct drm_mm_node *drm_mm_kmalloc(struct drm_mm *mm, int atomic)
+{
+        struct drm_mm_node *child;
+
+        if (atomic)
+                child = kmalloc(sizeof(*child), GFP_ATOMIC);
+        else
+                child = kmalloc(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, fl_entry);
+                        list_del(&child->fl_entry);
+                        --mm->num_unused;
+                }
+                spin_unlock(&mm->unused_lock);
+        }
+        return child;
+}
+
+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 = kmalloc(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->fl_entry, &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)
+                                   unsigned long start,
+                                   unsigned long size, int atomic)
 {
         struct drm_mm_node *child;
 
-        child = (struct drm_mm_node *)
-                drm_alloc(sizeof(*child), DRM_MEM_MM);
-        if (!child)
+        child = drm_mm_kmalloc(mm, atomic);
+        if (unlikely(child == NULL))
                 return -ENOMEM;
 
         child->free = 1;
@@ -97,8 +146,7 @@ static int drm_mm_create_tail_node(struct drm_mm *mm,
         return 0;
 }
 
-
-int drm_mm_add_space_to_tail(struct drm_mm *mm, unsigned long size)
+int drm_mm_add_space_to_tail(struct drm_mm *mm, unsigned long size, int atomic)
 {
         struct list_head *tail_node;
         struct drm_mm_node *entry;
@@ -106,20 +154,21 @@ int drm_mm_add_space_to_tail(struct drm_mm *mm, unsigned long size)
         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);
+                return drm_mm_create_tail_node(mm, entry->start + entry->size,
+                                               size, atomic);
         }
         entry->size += size;
         return 0;
 }
 
 static struct drm_mm_node *drm_mm_split_at_start(struct drm_mm_node *parent,
-                                            unsigned long size)
+                                                 unsigned long size,
+                                                 int atomic)
 {
         struct drm_mm_node *child;
 
-        child = (struct drm_mm_node *)
-                drm_alloc(sizeof(*child), DRM_MEM_MM);
-        if (!child)
+        child = drm_mm_kmalloc(parent->mm, atomic);
+        if (unlikely(child == NULL))
                 return NULL;
 
         INIT_LIST_HEAD(&child->fl_entry);
@@ -151,8 +200,9 @@ struct drm_mm_node *drm_mm_get_block(struct drm_mm_node * parent,
                 tmp = parent->start % alignment;
 
         if (tmp) {
-                align_splitoff = drm_mm_split_at_start(parent, alignment - tmp);
-                if (!align_splitoff)
+                align_splitoff =
+                    drm_mm_split_at_start(parent, alignment - tmp, 0);
+                if (unlikely(align_splitoff == NULL))
                         return NULL;
         }
 
@@ -161,7 +211,7 @@ struct drm_mm_node *drm_mm_get_block(struct drm_mm_node * parent,
                 parent->free = 0;
                 return parent;
         } else {
-                child = drm_mm_split_at_start(parent, size);
+                child = drm_mm_split_at_start(parent, size, 0);
         }
 
         if (align_splitoff)
@@ -169,14 +219,49 @@ struct drm_mm_node *drm_mm_get_block(struct drm_mm_node * parent,
 
         return child;
 }
+
 EXPORT_SYMBOL(drm_mm_get_block);
 
+struct drm_mm_node *drm_mm_get_block_atomic(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, 1);
+                if (unlikely(align_splitoff == NULL))
+                        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, 1);
+        }
+
+        if (align_splitoff)
+                drm_mm_put_block(align_splitoff);
+
+        return child;
+}
+EXPORT_SYMBOL(drm_mm_get_block_atomic);
+
 /*
  * 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)
+void drm_mm_put_block(struct drm_mm_node *cur)
 {
 
         struct drm_mm *mm = cur->mm;
@@ -188,21 +273,27 @@ void drm_mm_put_block(struct drm_mm_node * cur)
         int merged = 0;
 
         if (cur_head->prev != root_head) {
-                prev_node = list_entry(cur_head->prev, struct drm_mm_node, ml_entry);
+                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);
+                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);
+                                if (mm->num_unused < MM_UNUSED_TARGET) {
+                                        list_add(&next_node->fl_entry,
+                                                 &mm->unused_nodes);
+                                        ++mm->num_unused;
+                                } else
+                                        kfree(next_node);
                         } else {
                                 next_node->size += cur->size;
                                 next_node->start = cur->start;
@@ -215,14 +306,19 @@ void drm_mm_put_block(struct drm_mm_node * cur)
                 list_add(&cur->fl_entry, &mm->fl_entry);
         } else {
                 list_del(&cur->ml_entry);
-                drm_free(cur, sizeof(*cur), DRM_MEM_MM);
+                if (mm->num_unused < MM_UNUSED_TARGET) {
+                        list_add(&cur->fl_entry, &mm->unused_nodes);
+                        ++mm->num_unused;
+                } else
+                        kfree(cur);
         }
 }
+
 EXPORT_SYMBOL(drm_mm_put_block);
 
-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 *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;
@@ -247,7 +343,6 @@ struct drm_mm_node *drm_mm_search_free(const struct drm_mm * mm,
                                 wasted += alignment - tmp;
                 }
 
-
                 if (entry->size >= size + wasted) {
                         if (!best_match)
                                 return entry;
@@ -260,6 +355,7 @@ struct drm_mm_node *drm_mm_search_free(const struct drm_mm * mm,
 
         return best;
 }
+EXPORT_SYMBOL(drm_mm_search_free);
 
 int drm_mm_clean(struct drm_mm * mm)
 {
@@ -267,14 +363,17 @@ int drm_mm_clean(struct drm_mm * mm)
 
         return (head->next->next == head);
 }
-EXPORT_SYMBOL(drm_mm_search_free);
+EXPORT_SYMBOL(drm_mm_clean);
 
 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);
+        INIT_LIST_HEAD(&mm->unused_nodes);
+        mm->num_unused = 0;
+        spin_lock_init(&mm->unused_lock);
 
-        return drm_mm_create_tail_node(mm, start, size);
+        return drm_mm_create_tail_node(mm, start, size, 0);
 }
 EXPORT_SYMBOL(drm_mm_init);
 
@@ -282,6 +381,7 @@ void drm_mm_takedown(struct drm_mm * mm)
 {
         struct list_head *bnode = mm->fl_entry.next;
         struct drm_mm_node *entry;
+        struct drm_mm_node *next;
 
         entry = list_entry(bnode, struct drm_mm_node, fl_entry);
 
@@ -293,7 +393,16 @@ void drm_mm_takedown(struct drm_mm * mm)
 
         list_del(&entry->fl_entry);
         list_del(&entry->ml_entry);
+        kfree(entry);
+
+        spin_lock(&mm->unused_lock);
+        list_for_each_entry_safe(entry, next, &mm->unused_nodes, fl_entry) {
+                list_del(&entry->fl_entry);
+                kfree(entry);
+                --mm->num_unused;
+        }
+        spin_unlock(&mm->unused_lock);
 
-        drm_free(entry, sizeof(*entry), DRM_MEM_MM);
+        BUG_ON(mm->num_unused != 0);
 }
 EXPORT_SYMBOL(drm_mm_takedown);