static void
l4ser_shm_rx_chars(struct uart_port *port)
{
struct l4ser_shm_uart_port *l4port = (struct l4ser_shm_uart_port *)port;
struct tty_struct *tty = port->state->port.tty;
struct chunk_head *chhead;
struct ring_chunk_head *rph;
unsigned long offs;
chhead = (struct chunk_head *)l4shmc_chunk_ptr(&l4port->rx_chunk);
offs = chhead->next_offs_to_read;
while (1) {
unsigned long l;
rph = (struct ring_chunk_head *)(l4port->rx_ring_start + offs);
if (!rph->size)
break;
offs += sizeof(struct ring_chunk_head);
offs %= l4port->rx_ring_size;
if (offs + rph->size > l4port->rx_ring_size)
l = l4port->rx_ring_size - offs;
else
l = rph->size;
port->icount.rx += rph->size;
tty_insert_flip_string(tty,
(const unsigned char *)l4port->rx_ring_start + offs,
l);
if (l != rph->size)
tty_insert_flip_string(tty,
(const unsigned char *)l4port->rx_ring_start,
rph->size - l);
offs = (offs + rph->size + sizeof(struct ring_chunk_head) - 1)
& ~(sizeof(struct ring_chunk_head) - 1);
offs %= l4port->rx_ring_size;
chhead->next_offs_to_read = offs;
rph->size = 0;
}
tty_flip_buffer_push(tty);
if (chhead->writer_blocked) {
L4XV_V(f);
L4XV_L(f);
l4shmc_trigger(&l4port->tx_sig);
L4XV_U(f);
}
chhead = (struct chunk_head *)l4shmc_chunk_ptr(&l4port->tx_chunk);
chhead->writer_blocked = 0;
return;
}
static void l4ser_shm_tx_chars(struct uart_port *port)
{
struct l4ser_shm_uart_port *l4port = (struct l4ser_shm_uart_port *)port;
struct circ_buf *xmit = &port->state->xmit;
int c, do_trigger = 0;
struct tty_struct *tty = port->state->port.tty;
tty->hw_stopped = 0;
tty->stopped = 0;
if (port->x_char) {
if (tx_buf(port, &port->x_char, 1)) {
L4XV_V(f);
port->icount.tx++;
port->x_char = 0;
L4XV_L(f);
l4shmc_trigger(&l4port->tx_sig);
L4XV_U(f);
}
return;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
return;
}
while (!uart_circ_empty(xmit)) {
unsigned long r;
c = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
if (!(r = tx_buf(port, &xmit->buf[xmit->tail], c)))
break;
xmit->tail = (xmit->tail + r) & (UART_XMIT_SIZE - 1);
port->icount.tx += r;
do_trigger = 1;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
if (do_trigger) {
L4XV_V(f);
L4XV_L(f);
l4shmc_trigger(&l4port->tx_sig);
L4XV_U(f);
}
}
static void *thread_consume(void *d)
{
(void)d;
l4shmc_area_t shmarea;
l4shmc_chunk_t p_one;
l4shmc_signal_t s_one, s_done;
// attach to shared memory area
CHK(l4shmc_attach("testshm", &shmarea));
// get chunk 'one'
CHK(l4shmc_get_chunk(&shmarea, "one", &p_one));
// add a signal
CHK(l4shmc_add_signal(&shmarea, "done", &s_done));
// attach signal to this thread
CHK(l4shmc_attach_signal_to(&shmarea, "prod",
pthread_l4_cap(pthread_self()), 10000, &s_one));
// connect chunk and signal
CHK(l4shmc_connect_chunk_signal(&p_one, &s_one));
while (1)
{
CHK(l4shmc_wait_chunk(&p_one));
printf("CONSUMER: Received from chunk one: %s\n",
(char *)l4shmc_chunk_ptr(&p_one));
memset(l4shmc_chunk_ptr(&p_one), 0, l4shmc_chunk_size(&p_one));
CHK(l4shmc_chunk_consumed(&p_one));
CHK(l4shmc_trigger(&s_done));
}
return NULL;
}
static unsigned long tx_buf(struct uart_port *port, const char *chunk, int length)
{
struct l4ser_shm_uart_port *l4port = (struct l4ser_shm_uart_port *)port;
struct chunk_head *chhead;
struct ring_chunk_head *rph;
unsigned long l, offs, nextoffs, free_bytes;
unsigned long flags;
struct tty_struct *tty = port->state->port.tty;
spin_lock_irqsave(&txlock, flags);
chhead = (struct chunk_head *)l4shmc_chunk_ptr(&l4port->tx_chunk);
offs = chhead->next_offs_to_write;
rph = (struct ring_chunk_head *)(l4port->tx_ring_start + offs);
BUILD_BUG_ON(sizeof(struct ring_chunk_head) & (sizeof(struct ring_chunk_head) - 1));
// get max free space
if (chhead->next_offs_to_write >= chhead->next_offs_to_read)
free_bytes = l4port->tx_ring_size - (chhead->next_offs_to_write - chhead->next_offs_to_read);
else
free_bytes = chhead->next_offs_to_read - chhead->next_offs_to_write;
if (free_bytes <= sizeof(struct ring_chunk_head) * 2) {
chhead->writer_blocked = 1;
spin_unlock_irqrestore(&txlock, flags);
tty->hw_stopped = 1;
tty->stopped = 1;
l4shmc_trigger(&l4port->tx_sig);
return 0;
}
if (length > free_bytes - sizeof(struct ring_chunk_head) * 2)
length = free_bytes - sizeof(struct ring_chunk_head) * 2;
nextoffs = (offs + length + sizeof(struct ring_chunk_head) + sizeof(struct ring_chunk_head) - 1)
& ~(sizeof(struct ring_chunk_head) - 1);
nextoffs %= l4port->tx_ring_size;
offs += sizeof(struct ring_chunk_head);
offs %= l4port->tx_ring_size;
if (offs + length > l4port->tx_ring_size)
l = l4port->tx_ring_size - offs;
else
l = length;
memcpy(l4port->tx_ring_start + offs, chunk, l);
if (l != length)
memcpy(l4port->tx_ring_start, chunk + l, length - l);
// now write header
((struct ring_chunk_head *)(l4port->tx_ring_start + nextoffs))->size = 0;
smp_wmb();
rph->size = length;
chhead->next_offs_to_write = nextoffs;
spin_unlock_irqrestore(&txlock, flags);
return length;
}
