staging: most: hdm-dim2: round up DBR memory for async/ctrl

As the DBR memory is allocated in units of DBR_BLOCK_SIZE, it is more
efficient to configure the DIM2 IP to use whole blocks of the DBR memory.
This patch ceils the DBR memory size used by the DIM2 IP for async/ctrl
channels.
Signed-off-by: Andrey Shvetsov <andrey.shvetsov@k2l.de>
Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/most/hdm-dim2/dim2_hal.c

@@ -49,6 +49,8 @@
 #define DBR_SIZE  (16 * 1024) /* specified by IP */
 #define DBR_BLOCK_SIZE  (DBR_SIZE / 32 / DBR_MAP_SIZE)
 
+#define ROUND_UP_TO(x, d)  (((x) + (d) - 1) / (d) * (d))
+
 /* -------------------------------------------------------------------------- */
 /* generic helper functions and macros */
 
@@ -698,7 +700,7 @@ static u8 init_ctrl_async(struct dim_channel *ch, u8 type, u8 is_tx,
 	if (!check_channel_address(ch_address))
 		return DIM_INIT_ERR_CHANNEL_ADDRESS;
 
-	ch->dbr_size = hw_buffer_size;
+	ch->dbr_size = ROUND_UP_TO(hw_buffer_size, DBR_BLOCK_SIZE);
 	ch->dbr_addr = alloc_dbr(ch->dbr_size);
 	if (ch->dbr_addr >= DBR_SIZE)
 		return DIM_INIT_ERR_OUT_OF_MEMORY;