drm/ttm: convert to the reservation api

Now that the code is compatible in semantics, flip the switch.
Use ww_mutex instead of the homegrown implementation.

ww_mutex uses -EDEADLK to signal that the caller has to back off,
and -EALREADY to indicate this buffer is already held by the caller.

ttm used -EAGAIN and -EDEADLK for those, respectively. So some changes
were needed to handle this correctly.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

2 files changed, 6 insertions, 20 deletions

diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index 0a992b016fe9..31ad860c10cd 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -39,6 +39,7 @@
 #include <linux/mm.h>
 #include <linux/rbtree.h>
 #include <linux/bitmap.h>
+#include <linux/reservation.h>
 
 struct ttm_bo_device;
 
@@ -153,7 +154,6 @@ struct ttm_tt;
  * Lru lists may keep one refcount, the delayed delete list, and kref != 0
  * keeps one refcount. When this refcount reaches zero,
  * the object is destroyed.
- * @event_queue: Queue for processes waiting on buffer object status change.
  * @mem: structure describing current placement.
  * @persistent_swap_storage: Usually the swap storage is deleted for buffers
  * pinned in physical memory. If this behaviour is not desired, this member
@@ -164,12 +164,6 @@ struct ttm_tt;
  * @lru: List head for the lru list.
  * @ddestroy: List head for the delayed destroy list.
  * @swap: List head for swap LRU list.
- * @val_seq: Sequence of the validation holding the @reserved lock.
- * Used to avoid starvation when many processes compete to validate the
- * buffer. This member is protected by the bo_device::lru_lock.
- * @seq_valid: The value of @val_seq is valid. This value is protected by
- * the bo_device::lru_lock.
- * @reserved: Deadlock-free lock used for synchronization state transitions.
  * @sync_obj: Pointer to a synchronization object.
  * @priv_flags: Flags describing buffer object internal state.
  * @vm_rb: Rb node for the vm rb tree.
@@ -209,10 +203,9 @@ struct ttm_buffer_object {
 
         struct kref kref;
         struct kref list_kref;
-        wait_queue_head_t event_queue;
 
         /**
-         * Members protected by the bo::reserved lock.
+         * Members protected by the bo::resv::reserved lock.
          */
 
         struct ttm_mem_reg mem;
@@ -234,15 +227,6 @@ struct ttm_buffer_object {
         struct list_head ddestroy;
         struct list_head swap;
         struct list_head io_reserve_lru;
-        unsigned long val_seq;
-        bool seq_valid;
-
-        /**
-         * Members protected by the bdev::lru_lock
-         * only when written to.
-         */
-
-        atomic_t reserved;
 
         /**
          * Members protected by struct buffer_object_device::fence_lock
@@ -272,6 +256,9 @@ struct ttm_buffer_object {
         uint32_t cur_placement;
 
         struct sg_table *sg;
+
+        struct reservation_object *resv;
+        struct reservation_object ttm_resv;
 };
 
 /**
@@ -736,7 +723,7 @@ extern void ttm_bo_swapout_all(struct ttm_bo_device *bdev);
  */
 static inline bool ttm_bo_is_reserved(struct ttm_buffer_object *bo)
 {
-        return atomic_read(&bo->reserved);
+        return ww_mutex_is_locked(&bo->resv->lock);
 }
 
 #endif
diff --git a/include/drm/ttm/ttm_execbuf_util.h b/include/drm/ttm/ttm_execbuf_util.h
index ba71ef91f4d5..ec8a1d306510 100644
--- a/include/drm/ttm/ttm_execbuf_util.h
+++ b/include/drm/ttm/ttm_execbuf_util.h
@@ -33,7 +33,6 @@
 
 #include <ttm/ttm_bo_api.h>
 #include <linux/list.h>
-#include <linux/reservation.h>
 
 /**
  * struct ttm_validate_buffer