drm: omapdrm: Remove legacy buffer synchronization support

The omapdrm driver uses a custom API to synchronize with the SGX GPU.
This is unusable as such in the mainline kernel as the API is only
partially implemented and requires additional out-of-tree patches.
Furthermore, as no SGX driver is available in the mainline kernel, the
API can't be considered as a stable mainline API.

Now that the driver supports synchronization through fences, remove
legacy buffer synchronization support. The two userspace ioctls are
turned into no-ops to avoid breaking userspace and will be removed in
the future.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

3 files changed, 4 insertions, 268 deletions

diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c b/drivers/gpu/drm/omapdrm/omap_drv.c
index b4ef3025e3e3..e2e935813cc4 100644
--- a/drivers/gpu/drm/omapdrm/omap_drv.c
+++ b/drivers/gpu/drm/omapdrm/omap_drv.c
@@ -365,53 +365,6 @@ static int ioctl_gem_new(struct drm_device *dev, void *data,
                                    &args->handle);
 }
 
-static int ioctl_gem_cpu_prep(struct drm_device *dev, void *data,
-                struct drm_file *file_priv)
-{
-        struct drm_omap_gem_cpu_prep *args = data;
-        struct drm_gem_object *obj;
-        int ret;
-
-        VERB("%p:%p: handle=%d, op=%x", dev, file_priv, args->handle, args->op);
-
-        obj = drm_gem_object_lookup(file_priv, args->handle);
-        if (!obj)
-                return -ENOENT;
-
-        ret = omap_gem_op_sync(obj, args->op);
-
-        if (!ret)
-                ret = omap_gem_op_start(obj, args->op);
-
-        drm_gem_object_unreference_unlocked(obj);
-
-        return ret;
-}
-
-static int ioctl_gem_cpu_fini(struct drm_device *dev, void *data,
-                struct drm_file *file_priv)
-{
-        struct drm_omap_gem_cpu_fini *args = data;
-        struct drm_gem_object *obj;
-        int ret;
-
-        VERB("%p:%p: handle=%d", dev, file_priv, args->handle);
-
-        obj = drm_gem_object_lookup(file_priv, args->handle);
-        if (!obj)
-                return -ENOENT;
-
-        /* XXX flushy, flushy */
-        ret = 0;
-
-        if (!ret)
-                ret = omap_gem_op_finish(obj, args->op);
-
-        drm_gem_object_unreference_unlocked(obj);
-
-        return ret;
-}
-
 static int ioctl_gem_info(struct drm_device *dev, void *data,
                 struct drm_file *file_priv)
 {
@@ -440,9 +393,11 @@ static const struct drm_ioctl_desc ioctls[DRM_COMMAND_END - DRM_COMMAND_BASE] =
                           DRM_AUTH | DRM_MASTER | DRM_ROOT_ONLY),
         DRM_IOCTL_DEF_DRV(OMAP_GEM_NEW, ioctl_gem_new,
                           DRM_AUTH | DRM_RENDER_ALLOW),
-        DRM_IOCTL_DEF_DRV(OMAP_GEM_CPU_PREP, ioctl_gem_cpu_prep,
+        /* Deprecated, to be removed. */
+        DRM_IOCTL_DEF_DRV(OMAP_GEM_CPU_PREP, drm_noop,
                           DRM_AUTH | DRM_RENDER_ALLOW),
-        DRM_IOCTL_DEF_DRV(OMAP_GEM_CPU_FINI, ioctl_gem_cpu_fini,
+        /* Deprecated, to be removed. */
+        DRM_IOCTL_DEF_DRV(OMAP_GEM_CPU_FINI, drm_noop,
                           DRM_AUTH | DRM_RENDER_ALLOW),
         DRM_IOCTL_DEF_DRV(OMAP_GEM_INFO, ioctl_gem_info,
                           DRM_AUTH | DRM_RENDER_ALLOW),
diff --git a/drivers/gpu/drm/omapdrm/omap_drv.h b/drivers/gpu/drm/omapdrm/omap_drv.h
index 54e6055ea1d3..16aa43c6fbc2 100644
--- a/drivers/gpu/drm/omapdrm/omap_drv.h
+++ b/drivers/gpu/drm/omapdrm/omap_drv.h
@@ -184,11 +184,6 @@ int omap_gem_mmap(struct file *filp, struct vm_area_struct *vma);
 int omap_gem_mmap_obj(struct drm_gem_object *obj,
                 struct vm_area_struct *vma);
 int omap_gem_fault(struct vm_fault *vmf);
-int omap_gem_op_start(struct drm_gem_object *obj, enum omap_gem_op op);
-int omap_gem_op_finish(struct drm_gem_object *obj, enum omap_gem_op op);
-int omap_gem_op_sync(struct drm_gem_object *obj, enum omap_gem_op op);
-int omap_gem_op_async(struct drm_gem_object *obj, enum omap_gem_op op,
-                void (*fxn)(void *arg), void *arg);
 int omap_gem_roll(struct drm_gem_object *obj, uint32_t roll);
 void omap_gem_cpu_sync(struct drm_gem_object *obj, int pgoff);
 void omap_gem_dma_sync(struct drm_gem_object *obj,
diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c b/drivers/gpu/drm/omapdrm/omap_gem.c
index 68a75b829b71..4bb52a5f5939 100644
--- a/drivers/gpu/drm/omapdrm/omap_gem.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem.c
@@ -101,19 +101,6 @@ struct omap_gem_object {
          * Virtual address, if mapped.
          */
         void *vaddr;
-
-        /**
-         * sync-object allocated on demand (if needed)
-         *
-         * Per-buffer sync-object for tracking pending and completed hw/dma
-         * read and write operations.
-         */
-        struct {
-                uint32_t write_pending;
-                uint32_t write_complete;
-                uint32_t read_pending;
-                uint32_t read_complete;
-        } *sync;
 };
 
 #define to_omap_bo(x) container_of(x, struct omap_gem_object, base)
@@ -1071,205 +1058,6 @@ void omap_gem_describe_objects(struct list_head *list, struct seq_file *m)
 #endif
 
 /* -----------------------------------------------------------------------------
- * Buffer Synchronization
- */
-
-static DEFINE_SPINLOCK(sync_lock);
-
-struct omap_gem_sync_waiter {
-        struct list_head list;
-        struct omap_gem_object *omap_obj;
-        enum omap_gem_op op;
-        uint32_t read_target, write_target;
-        /* notify called w/ sync_lock held */
-        void (*notify)(void *arg);
-        void *arg;
-};
-
-/* list of omap_gem_sync_waiter.. the notify fxn gets called back when
- * the read and/or write target count is achieved which can call a user
- * callback (ex. to kick 3d and/or 2d), wakeup blocked task (prep for
- * cpu access), etc.
- */
-static LIST_HEAD(waiters);
-
-static inline bool is_waiting(struct omap_gem_sync_waiter *waiter)
-{
-        struct omap_gem_object *omap_obj = waiter->omap_obj;
-        if ((waiter->op & OMAP_GEM_READ) &&
-                        (omap_obj->sync->write_complete < waiter->write_target))
-                return true;
-        if ((waiter->op & OMAP_GEM_WRITE) &&
-                        (omap_obj->sync->read_complete < waiter->read_target))
-                return true;
-        return false;
-}
-
-/* macro for sync debug.. */
-#define SYNCDBG 0
-#define SYNC(fmt, ...) do { if (SYNCDBG)                                \
-                pr_err("%s:%d: " fmt "\n", __func__, __LINE__, ##__VA_ARGS__); \
-        } while (0)
-
-
-static void sync_op_update(void)
-{
-        struct omap_gem_sync_waiter *waiter, *n;
-        list_for_each_entry_safe(waiter, n, &waiters, list) {
-                if (!is_waiting(waiter)) {
-                        list_del(&waiter->list);
-                        SYNC("notify: %p", waiter);
-                        waiter->notify(waiter->arg);
-                        kfree(waiter);
-                }
-        }
-}
-
-static inline int sync_op(struct drm_gem_object *obj,
-                enum omap_gem_op op, bool start)
-{
-        struct omap_gem_object *omap_obj = to_omap_bo(obj);
-        int ret = 0;
-
-        spin_lock(&sync_lock);
-
-        if (!omap_obj->sync) {
-                omap_obj->sync = kzalloc(sizeof(*omap_obj->sync), GFP_ATOMIC);
-                if (!omap_obj->sync) {
-                        ret = -ENOMEM;
-                        goto unlock;
-                }
-        }
-
-        if (start) {
-                if (op & OMAP_GEM_READ)
-                        omap_obj->sync->read_pending++;
-                if (op & OMAP_GEM_WRITE)
-                        omap_obj->sync->write_pending++;
-        } else {
-                if (op & OMAP_GEM_READ)
-                        omap_obj->sync->read_complete++;
-                if (op & OMAP_GEM_WRITE)
-                        omap_obj->sync->write_complete++;
-                sync_op_update();
-        }
-
-unlock:
-        spin_unlock(&sync_lock);
-
-        return ret;
-}
-
-/* mark the start of read and/or write operation */
-int omap_gem_op_start(struct drm_gem_object *obj, enum omap_gem_op op)
-{
-        return sync_op(obj, op, true);
-}
-
-int omap_gem_op_finish(struct drm_gem_object *obj, enum omap_gem_op op)
-{
-        return sync_op(obj, op, false);
-}
-
-static DECLARE_WAIT_QUEUE_HEAD(sync_event);
-
-static void sync_notify(void *arg)
-{
-        struct task_struct **waiter_task = arg;
-        *waiter_task = NULL;
-        wake_up_all(&sync_event);
-}
-
-int omap_gem_op_sync(struct drm_gem_object *obj, enum omap_gem_op op)
-{
-        struct omap_gem_object *omap_obj = to_omap_bo(obj);
-        int ret = 0;
-        if (omap_obj->sync) {
-                struct task_struct *waiter_task = current;
-                struct omap_gem_sync_waiter *waiter =
-                                kzalloc(sizeof(*waiter), GFP_KERNEL);
-
-                if (!waiter)
-                        return -ENOMEM;
-
-                waiter->omap_obj = omap_obj;
-                waiter->op = op;
-                waiter->read_target = omap_obj->sync->read_pending;
-                waiter->write_target = omap_obj->sync->write_pending;
-                waiter->notify = sync_notify;
-                waiter->arg = &waiter_task;
-
-                spin_lock(&sync_lock);
-                if (is_waiting(waiter)) {
-                        SYNC("waited: %p", waiter);
-                        list_add_tail(&waiter->list, &waiters);
-                        spin_unlock(&sync_lock);
-                        ret = wait_event_interruptible(sync_event,
-                                        (waiter_task == NULL));
-                        spin_lock(&sync_lock);
-                        if (waiter_task) {
-                                SYNC("interrupted: %p", waiter);
-                                /* we were interrupted */
-                                list_del(&waiter->list);
-                                waiter_task = NULL;
-                        } else {
-                                /* freed in sync_op_update() */
-                                waiter = NULL;
-                        }
-                }
-                spin_unlock(&sync_lock);
-                kfree(waiter);
-        }
-        return ret;
-}
-
-/* call fxn(arg), either synchronously or asynchronously if the op
- * is currently blocked..  fxn() can be called from any context
- *
- * (TODO for now fxn is called back from whichever context calls
- * omap_gem_op_finish().. but this could be better defined later
- * if needed)
- *
- * TODO more code in common w/ _sync()..
- */
-int omap_gem_op_async(struct drm_gem_object *obj, enum omap_gem_op op,
-                void (*fxn)(void *arg), void *arg)
-{
-        struct omap_gem_object *omap_obj = to_omap_bo(obj);
-        if (omap_obj->sync) {
-                struct omap_gem_sync_waiter *waiter =
-                                kzalloc(sizeof(*waiter), GFP_ATOMIC);
-
-                if (!waiter)
-                        return -ENOMEM;
-
-                waiter->omap_obj = omap_obj;
-                waiter->op = op;
-                waiter->read_target = omap_obj->sync->read_pending;
-                waiter->write_target = omap_obj->sync->write_pending;
-                waiter->notify = fxn;
-                waiter->arg = arg;
-
-                spin_lock(&sync_lock);
-                if (is_waiting(waiter)) {
-                        SYNC("waited: %p", waiter);
-                        list_add_tail(&waiter->list, &waiters);
-                        spin_unlock(&sync_lock);
-                        return 0;
-                }
-
-                spin_unlock(&sync_lock);
-
-                kfree(waiter);
-        }
-
-        /* no waiting.. */
-        fxn(arg);
-
-        return 0;
-}
-
-/* -----------------------------------------------------------------------------
  * Constructor & Destructor
  */
 
@@ -1308,8 +1096,6 @@ void omap_gem_free_object(struct drm_gem_object *obj)
                 drm_prime_gem_destroy(obj, omap_obj->sgt);
         }
 
-        kfree(omap_obj->sync);
-
         drm_gem_object_release(obj);
 
         kfree(omap_obj);