drm/etnaviv: move cmdbuf into submit object

Less dynamic allocations and slims down the cmdbuf object to only the
required information, as everything else is already available in the
submit object.

This also simplifies buffer and mappings lifetime management, as they
are now exlusively attached to the submit object and not additionally
to the cmdbuf.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

drivers/gpu/drm/etnaviv/etnaviv_buffer.c

@@ -166,7 +166,7 @@ static u32 etnaviv_buffer_reserve(struct etnaviv_gpu *gpu,
 
 u16 etnaviv_buffer_init(struct etnaviv_gpu *gpu)
 {
-	struct etnaviv_cmdbuf *buffer = gpu->buffer;
+	struct etnaviv_cmdbuf *buffer = &gpu->buffer;
 
 	lockdep_assert_held(&gpu->lock);
 
@@ -182,7 +182,7 @@ u16 etnaviv_buffer_init(struct etnaviv_gpu *gpu)
 
 u16 etnaviv_buffer_config_mmuv2(struct etnaviv_gpu *gpu, u32 mtlb_addr, u32 safe_addr)
 {
-	struct etnaviv_cmdbuf *buffer = gpu->buffer;
+	struct etnaviv_cmdbuf *buffer = &gpu->buffer;
 
 	lockdep_assert_held(&gpu->lock);
 
@@ -217,7 +217,7 @@ u16 etnaviv_buffer_config_mmuv2(struct etnaviv_gpu *gpu, u32 mtlb_addr, u32 safe
 
 void etnaviv_buffer_end(struct etnaviv_gpu *gpu)
 {
-	struct etnaviv_cmdbuf *buffer = gpu->buffer;
+	struct etnaviv_cmdbuf *buffer = &gpu->buffer;
 	unsigned int waitlink_offset = buffer->user_size - 16;
 	u32 link_target, flush = 0;
 
@@ -261,7 +261,7 @@ void etnaviv_buffer_end(struct etnaviv_gpu *gpu)
 /* Append a 'sync point' to the ring buffer. */
 void etnaviv_sync_point_queue(struct etnaviv_gpu *gpu, unsigned int event)
 {
-	struct etnaviv_cmdbuf *buffer = gpu->buffer;
+	struct etnaviv_cmdbuf *buffer = &gpu->buffer;
 	unsigned int waitlink_offset = buffer->user_size - 16;
 	u32 dwords, target;
 
@@ -300,7 +300,7 @@ void etnaviv_sync_point_queue(struct etnaviv_gpu *gpu, unsigned int event)
 void etnaviv_buffer_queue(struct etnaviv_gpu *gpu, u32 exec_state,
 	unsigned int event, struct etnaviv_cmdbuf *cmdbuf)
 {
-	struct etnaviv_cmdbuf *buffer = gpu->buffer;
+	struct etnaviv_cmdbuf *buffer = &gpu->buffer;
 	unsigned int waitlink_offset = buffer->user_size - 16;
 	u32 return_target, return_dwords;
 	u32 link_target, link_dwords;