Commit 5edbd330 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

media: vidtv: simplify PSI write function 



The function vidtv_psi_ts_psi_write_into() initializes the
ts_header fields several times, and receives a struct
as argument, instead of using a pointer to struct.

Cleanup the function, in order to reduce its stack usage
and to avoid initializing the ts_header multiple times.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
parent 16002854

drivers/media/test-drivers/vidtv/vidtv_psi.c

+63 −67
Original line number Diff line number Diff line
@@ -162,79 +162,75 @@ static void vidtv_psi_set_sec_len(struct vidtv_psi_table_header *h, u16 new_len) 
 * manage the continuity_counter

 * add stuffing (i.e. padding bytes) after the CRC

 */

static u32 vidtv_psi_ts_psi_write_into(struct psi_write_args args)

static u32 vidtv_psi_ts_psi_write_into(struct psi_write_args *args)

{



	u32 nbytes_past_boundary = (args.dest_offset % TS_PACKET_LEN);

	struct vidtv_mpeg_ts ts_header = {

		.sync_byte = TS_SYNC_BYTE,

		.bitfield = cpu_to_be16((args->new_psi_section << 14) | args->pid),

		.scrambling = 0,

		.payload = 1,

		.adaptation_field = 0, /* no adaptation field */

	};

	u32 nbytes_past_boundary = (args->dest_offset % TS_PACKET_LEN);

	bool aligned = (nbytes_past_boundary == 0);

	struct vidtv_mpeg_ts ts_header = {};

	u32 remaining_len = args.len;

	u32 remaining_len = args->len;

	u32 payload_write_len = 0;

	u32 payload_offset = 0;

	u32 nbytes = 0;



	const u16 PAYLOAD_START = args.new_psi_section;



	if (!args.crc && !args.is_crc)

	if (!args->crc && !args->is_crc)

		pr_warn_ratelimited("Missing CRC for chunk\n");



	if (args.crc)

		*args.crc = dvb_crc32(*args.crc, args.from, args.len);

	if (args->crc)

		*args->crc = dvb_crc32(*args->crc, args->from, args->len);



	if (args.new_psi_section && !aligned) {

	if (args->new_psi_section && !aligned) {

		pr_warn_ratelimited("Cannot write a new PSI section in a misaligned buffer\n");



		/* forcibly align and hope for the best */

		nbytes += vidtv_memset(args.dest_buf,

				       args.dest_offset + nbytes,

				       args.dest_buf_sz,

		nbytes += vidtv_memset(args->dest_buf,

				       args->dest_offset + nbytes,

				       args->dest_buf_sz,

				       TS_FILL_BYTE,

				       TS_PACKET_LEN - nbytes_past_boundary);

	}



	while (remaining_len) {

		nbytes_past_boundary = (args.dest_offset + nbytes) % TS_PACKET_LEN;

		nbytes_past_boundary = (args->dest_offset + nbytes) % TS_PACKET_LEN;

		aligned = (nbytes_past_boundary == 0);



		if (aligned) {

			/* if at a packet boundary, write a new TS header */

			ts_header.sync_byte = TS_SYNC_BYTE;

			ts_header.bitfield = cpu_to_be16((PAYLOAD_START << 14) | args.pid);

			ts_header.scrambling = 0;

			ts_header.continuity_counter = *args.continuity_counter;

			ts_header.payload = 1;

			/* no adaptation field */

			ts_header.adaptation_field = 0;



			/* copy the header */

			nbytes += vidtv_memcpy(args.dest_buf,

					       args.dest_offset + nbytes,

					       args.dest_buf_sz,

			ts_header.continuity_counter = *args->continuity_counter;



			nbytes += vidtv_memcpy(args->dest_buf,

					       args->dest_offset + nbytes,

					       args->dest_buf_sz,

					       &ts_header,

					       sizeof(ts_header));

			/*

			 * This will trigger a discontinuity if the buffer is full,

			 * effectively dropping the packet.

			 */

			vidtv_ts_inc_cc(args.continuity_counter);

			vidtv_ts_inc_cc(args->continuity_counter);

		}



		/* write the pointer_field in the first byte of the payload */

		if (args.new_psi_section)

			nbytes += vidtv_memset(args.dest_buf,

					       args.dest_offset + nbytes,

					       args.dest_buf_sz,

		if (args->new_psi_section)

			nbytes += vidtv_memset(args->dest_buf,

					       args->dest_offset + nbytes,

					       args->dest_buf_sz,

					       0x0,

					       1);



		/* write as much of the payload as possible */

		nbytes_past_boundary = (args.dest_offset + nbytes) % TS_PACKET_LEN;

		nbytes_past_boundary = (args->dest_offset + nbytes) % TS_PACKET_LEN;

		payload_write_len = min(TS_PACKET_LEN - nbytes_past_boundary, remaining_len);



		nbytes += vidtv_memcpy(args.dest_buf,

				       args.dest_offset + nbytes,

				       args.dest_buf_sz,

				       args.from + payload_offset,

		nbytes += vidtv_memcpy(args->dest_buf,

				       args->dest_offset + nbytes,

				       args->dest_buf_sz,

				       args->from + payload_offset,

				       payload_write_len);



		/* 'payload_write_len' written from a total of 'len' requested*/
@@ -246,12 +242,12 @@ static u32 vidtv_psi_ts_psi_write_into(struct psi_write_args args) 
	 * fill the rest of the packet if there is any remaining space unused

	 */



	nbytes_past_boundary = (args.dest_offset + nbytes) % TS_PACKET_LEN;

	nbytes_past_boundary = (args->dest_offset + nbytes) % TS_PACKET_LEN;



	if (args.is_crc)

		nbytes += vidtv_memset(args.dest_buf,

				       args.dest_offset + nbytes,

				       args.dest_buf_sz,

	if (args->is_crc)

		nbytes += vidtv_memset(args->dest_buf,

				       args->dest_offset + nbytes,

				       args->dest_buf_sz,

				       TS_FILL_BYTE,

				       TS_PACKET_LEN - nbytes_past_boundary);
@@ -275,7 +271,7 @@ static u32 table_section_crc32_write_into(struct crc32_write_args args) 
	psi_args.is_crc             = true;

	psi_args.dest_buf_sz        = args.dest_buf_sz;



	nbytes += vidtv_psi_ts_psi_write_into(psi_args);

	nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



	return nbytes;

}
@@ -662,7 +658,7 @@ static u32 vidtv_psi_desc_write_into(struct desc_write_args args) 
	psi_args.dest_buf_sz        = args.dest_buf_sz;

	psi_args.crc                = args.crc;



	nbytes += vidtv_psi_ts_psi_write_into(psi_args);

	nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



	switch (args.desc->type) {

	case SERVICE_DESCRIPTOR:
@@ -671,25 +667,25 @@ static u32 vidtv_psi_desc_write_into(struct desc_write_args args) 
			       sizeof_field(struct vidtv_psi_desc_service, provider_name_len);

		psi_args.from = &((struct vidtv_psi_desc_service *)args.desc)->service_type;



		nbytes += vidtv_psi_ts_psi_write_into(psi_args);

		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



		psi_args.dest_offset = args.dest_offset + nbytes;

		psi_args.len = ((struct vidtv_psi_desc_service *)args.desc)->provider_name_len;

		psi_args.from = ((struct vidtv_psi_desc_service *)args.desc)->provider_name;



		nbytes += vidtv_psi_ts_psi_write_into(psi_args);

		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



		psi_args.dest_offset = args.dest_offset + nbytes;

		psi_args.len = sizeof_field(struct vidtv_psi_desc_service, service_name_len);

		psi_args.from = &((struct vidtv_psi_desc_service *)args.desc)->service_name_len;



		nbytes += vidtv_psi_ts_psi_write_into(psi_args);

		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



		psi_args.dest_offset = args.dest_offset + nbytes;

		psi_args.len = ((struct vidtv_psi_desc_service *)args.desc)->service_name_len;

		psi_args.from = ((struct vidtv_psi_desc_service *)args.desc)->service_name;



		nbytes += vidtv_psi_ts_psi_write_into(psi_args);

		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);

		break;



	case NETWORK_NAME_DESCRIPTOR:
@@ -697,7 +693,7 @@ static u32 vidtv_psi_desc_write_into(struct desc_write_args args) 
		psi_args.len = args.desc->length;

		psi_args.from = ((struct vidtv_psi_desc_network_name *)args.desc)->network_name;



		nbytes += vidtv_psi_ts_psi_write_into(psi_args);

		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);

		break;



	case SERVICE_LIST_DESCRIPTOR:
@@ -708,7 +704,7 @@ static u32 vidtv_psi_desc_write_into(struct desc_write_args args) 
				       sizeof(struct vidtv_psi_desc_service_list_entry *);

			psi_args.from = serv_list_entry;



			nbytes += vidtv_psi_ts_psi_write_into(psi_args);

			nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



			serv_list_entry = serv_list_entry->next;

		}
@@ -720,32 +716,32 @@ static u32 vidtv_psi_desc_write_into(struct desc_write_args args) 
		psi_args.from = ((struct vidtv_psi_desc_short_event *)

				  args.desc)->iso_language_code;



		nbytes += vidtv_psi_ts_psi_write_into(psi_args);

		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



		psi_args.dest_offset = args.dest_offset + nbytes;

		psi_args.len = sizeof_field(struct vidtv_psi_desc_short_event, event_name_len);

		psi_args.from = &((struct vidtv_psi_desc_short_event *)

				  args.desc)->event_name_len;



		nbytes += vidtv_psi_ts_psi_write_into(psi_args);

		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



		psi_args.dest_offset = args.dest_offset + nbytes;

		psi_args.len = ((struct vidtv_psi_desc_short_event *)args.desc)->event_name_len;

		psi_args.from = ((struct vidtv_psi_desc_short_event *)args.desc)->event_name;



		nbytes += vidtv_psi_ts_psi_write_into(psi_args);

		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



		psi_args.dest_offset = args.dest_offset + nbytes;

		psi_args.len = sizeof_field(struct vidtv_psi_desc_short_event, text_len);

		psi_args.from = &((struct vidtv_psi_desc_short_event *)args.desc)->text_len;



		nbytes += vidtv_psi_ts_psi_write_into(psi_args);

		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



		psi_args.dest_offset = args.dest_offset + nbytes;

		psi_args.len = ((struct vidtv_psi_desc_short_event *)args.desc)->text_len;

		psi_args.from = ((struct vidtv_psi_desc_short_event *)args.desc)->text;



		nbytes += vidtv_psi_ts_psi_write_into(psi_args);

		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



		break;
@@ -755,7 +751,7 @@ static u32 vidtv_psi_desc_write_into(struct desc_write_args args) 
		psi_args.len = args.desc->length;

		psi_args.from = &args.desc->data;



		nbytes += vidtv_psi_ts_psi_write_into(psi_args);

		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);

		break;

	}
@@ -780,7 +776,7 @@ vidtv_psi_table_header_write_into(struct header_write_args args) 
	psi_args.dest_buf_sz        = args.dest_buf_sz;

	psi_args.crc                = args.crc;



	nbytes += vidtv_psi_ts_psi_write_into(psi_args);

	nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



	return nbytes;

}
@@ -1014,7 +1010,7 @@ u32 vidtv_psi_pat_write_into(struct vidtv_psi_pat_write_args args) 
			   sizeof(struct vidtv_psi_table_pat_program *);

		psi_args.dest_offset = args.offset + nbytes;



		nbytes += vidtv_psi_ts_psi_write_into(psi_args);

		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



		p = p->next;

	}
@@ -1207,7 +1203,7 @@ u32 vidtv_psi_pmt_write_into(struct vidtv_psi_pmt_write_args args) 
	psi_args.dest_buf_sz        = args.buf_sz;

	psi_args.crc                = &crc;



	nbytes += vidtv_psi_ts_psi_write_into(psi_args);

	nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



	while (table_descriptor) {

		/* write the descriptors, if any */
@@ -1232,7 +1228,7 @@ u32 vidtv_psi_pmt_write_into(struct vidtv_psi_pmt_write_args args) 
				sizeof_field(struct vidtv_psi_table_pmt_stream, bitfield2);

		psi_args.dest_offset = args.offset + nbytes;



		nbytes += vidtv_psi_ts_psi_write_into(psi_args);

		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



		stream_descriptor = stream->descriptor;
@@ -1360,7 +1356,7 @@ u32 vidtv_psi_sdt_write_into(struct vidtv_psi_sdt_write_args args) 
	psi_args.crc                = &crc;



	/* copy u16 network_id + u8 reserved)*/

	nbytes += vidtv_psi_ts_psi_write_into(psi_args);

	nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



	while (service) {

		/* copy the services, if any */
@@ -1371,7 +1367,7 @@ u32 vidtv_psi_sdt_write_into(struct vidtv_psi_sdt_write_args args) 
			       sizeof(struct vidtv_psi_table_sdt_service *);

		psi_args.dest_offset = args.offset + nbytes;



		nbytes += vidtv_psi_ts_psi_write_into(psi_args);

		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



		service_desc = service->descriptor;
@@ -1694,7 +1690,7 @@ u32 vidtv_psi_nit_write_into(struct vidtv_psi_nit_write_args args) 
	psi_args.dest_buf_sz        = args.buf_sz;

	psi_args.crc                = &crc;



	nbytes += vidtv_psi_ts_psi_write_into(psi_args);

	nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



	while (table_descriptor) {

		/* write the descriptors, if any */
@@ -1718,7 +1714,7 @@ u32 vidtv_psi_nit_write_into(struct vidtv_psi_nit_write_args args) 
	psi_args.dest_offset = args.offset + nbytes;

	psi_args.pid = VIDTV_NIT_PID;



	nbytes += vidtv_psi_ts_psi_write_into(psi_args);

	nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



	while (transport) {

		/* write the transport sections, if any */
@@ -1728,7 +1724,7 @@ u32 vidtv_psi_nit_write_into(struct vidtv_psi_nit_write_args args) 
				sizeof_field(struct vidtv_psi_table_transport, bitfield);

		psi_args.dest_offset = args.offset + nbytes;



		nbytes += vidtv_psi_ts_psi_write_into(psi_args);

		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



		transport_descriptor = transport->descriptor;
@@ -1907,7 +1903,7 @@ u32 vidtv_psi_eit_write_into(struct vidtv_psi_eit_write_args args) 
	psi_args.dest_buf_sz        = args.buf_sz;

	psi_args.crc                = &crc;



	nbytes += vidtv_psi_ts_psi_write_into(psi_args);

	nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



	while (event) {

		/* copy the events, if any */
@@ -1918,7 +1914,7 @@ u32 vidtv_psi_eit_write_into(struct vidtv_psi_eit_write_args args) 
			       sizeof(struct vidtv_psi_table_eit_event *);

		psi_args.dest_offset = args.offset + nbytes;



		nbytes += vidtv_psi_ts_psi_write_into(psi_args);

		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);



		event_descriptor = event->descriptor;