Split serial RX and TX clients

drivers/serial/arm/uart.c

@@ -51,7 +51,7 @@ static void tx_provide(void)
     bool transferred = false;
     while (reprocess) {
         char c;
-        while (!(uart_regs->fr & PL011_FR_TXFF) && !serial_dequeue(&tx_queue_handle, &tx_queue_handle.queue->head, &c)) {
+        while (!(uart_regs->fr & PL011_FR_TXFF) && !serial_dequeue(&tx_queue_handle, NULL, &c)) {
             uart_regs->dr = (uint32_t)c;
             transferred = true;
         }
@@ -85,7 +85,7 @@ static void rx_return(void)
     while (reprocess) {
         while (!(uart_regs->fr & PL011_FR_RXFE) && !serial_queue_full(&rx_queue_handle, rx_queue_handle.queue->tail)) {
             char c = (char)(uart_regs->dr & PL011_DR_DATA_MASK);
-            serial_enqueue(&rx_queue_handle, &rx_queue_handle.queue->tail, c);
+            serial_enqueue(&rx_queue_handle, NULL, c);
             enqueued = true;
         }
 
@@ -149,7 +149,7 @@ static void uart_setup(void)
     uart_regs->lcr_h |= PL011_LCR_PARTY_EN;
 
     /* Enable receive interrupts when FIFO level exceeds 1/8 or after 32 ticks */
-#if !SERIAL_TX_ONLY
+#if SERIAL_NUM_RX_CLIENTS > 0
     uart_regs->ifls &= ~(PL011_IFLS_RX_MASK << PL011_IFLS_RX_SHFT);
     uart_regs->imsc |= (PL011_IMSC_RX_TIMEOUT | PL011_IMSC_RX_INT);
 #endif
@@ -165,7 +165,7 @@ static void uart_setup(void)
     uart_regs->tcr |= PL011_CR_TX_EN;
 
     /* Enable receive */
-#if !SERIAL_TX_ONLY
+#if SERIAL_NUM_RX_CLIENTS > 0
     uart_regs->tcr |= PL011_CR_RX_EN;
 #endif
 }
@@ -174,7 +174,7 @@ void init(void)
 {
     uart_setup();
 
-#if !SERIAL_TX_ONLY
+#if SERIAL_NUM_RX_CLIENTS > 0
     serial_queue_init(&rx_queue_handle, rx_queue, SERIAL_RX_DATA_REGION_CAPACITY_DRIV, rx_data);
 #endif
     serial_queue_init(&tx_queue_handle, tx_queue, SERIAL_TX_DATA_REGION_CAPACITY_DRIV, tx_data);

drivers/serial/imx/uart.c

@@ -52,8 +52,7 @@ static void tx_provide(void)
     bool transferred = false;
     while (reprocess) {
         char c;
-        while (!(uart_regs->ts & UART_TST_TX_FIFO_FULL)
-               && !serial_dequeue(&tx_queue_handle, &tx_queue_handle.queue->head, &c)) {
+        while (!(uart_regs->ts & UART_TST_TX_FIFO_FULL) && !serial_dequeue(&tx_queue_handle, NULL, &c)) {
             uart_regs->txd = (uint32_t)c;
             transferred = true;
         }
@@ -87,7 +86,7 @@ static void rx_return(void)
     while (reprocess) {
         while (!(uart_regs->ts & UART_TST_RX_FIFO_EMPTY) && !serial_queue_full(&rx_queue_handle, rx_queue_handle.queue->tail)) {
             char c = (char) uart_regs->rxd;
-            serial_enqueue(&rx_queue_handle, &rx_queue_handle.queue->tail, c);
+            serial_enqueue(&rx_queue_handle, NULL, c);
             enqueued = true;
         }
 
@@ -141,7 +140,7 @@ static void uart_setup(void)
 
     /* Enable transmit and receive */
     uart_regs->cr2 |= UART_CR2_TX_EN;
-#if !SERIAL_TX_ONLY
+#if SERIAL_NUM_RX_CLIENTS > 0
     uart_regs->cr2 |= UART_CR2_RX_EN;
 #endif
 
@@ -161,7 +160,7 @@ static void uart_setup(void)
 
     uint32_t fcr = uart_regs->fcr;
     /* Enable receive interrupts every byte */
-#if !SERIAL_TX_ONLY
+#if SERIAL_NUM_RX_CLIENTS > 0
     fcr &= ~UART_FCR_RXTL_MASK;
     fcr |= (1 << UART_FCR_RXTL_SHFT);
 #endif
@@ -171,7 +170,7 @@ static void uart_setup(void)
     fcr |= (2 << UART_FCR_TXTL_SHFT);
 
     uart_regs->fcr = fcr;
-#if !SERIAL_TX_ONLY
+#if SERIAL_NUM_RX_CLIENTS > 0
     uart_regs->cr1 |= UART_CR1_RX_READY_INT;
 #endif
 }
@@ -180,7 +179,7 @@ void init(void)
 {
     uart_setup();
 
-#if !SERIAL_TX_ONLY
+#if SERIAL_NUM_RX_CLIENTS > 0
     serial_queue_init(&rx_queue_handle, rx_queue, SERIAL_RX_DATA_REGION_CAPACITY_DRIV, rx_data);
 #endif
     serial_queue_init(&tx_queue_handle, tx_queue, SERIAL_TX_DATA_REGION_CAPACITY_DRIV, tx_data);

drivers/serial/meson/uart.c

@@ -76,7 +76,7 @@ static void tx_provide(void)
     bool transferred = false;
     while (reprocess) {
         char c;
-        while (!(uart_regs->sr & AML_UART_TX_FULL) && !serial_dequeue(&tx_queue_handle, &tx_queue_handle.queue->head, &c)) {
+        while (!(uart_regs->sr & AML_UART_TX_FULL) && !serial_dequeue(&tx_queue_handle, NULL, &c)) {
             uart_regs->wfifo = (uint32_t)c;
             transferred = true;
         }
@@ -110,7 +110,7 @@ static void rx_return(void)
     while (reprocess) {
         while (!(uart_regs->sr & AML_UART_RX_EMPTY) && !serial_queue_full(&rx_queue_handle, rx_queue_handle.queue->tail)) {
             char c = (char) uart_regs->rfifo;
-            serial_enqueue(&rx_queue_handle, &rx_queue_handle.queue->tail, c);
+            serial_enqueue(&rx_queue_handle, NULL, c);
             enqueued = true;
         }
 
@@ -186,7 +186,7 @@ static void uart_setup(void)
 
     uint32_t irqc = uart_regs->irqc;
     /* Enable receive interrupts every byte */
-#if !SERIAL_TX_ONLY
+#if SERIAL_NUM_RX_CLIENTS > 0
     irqc &= ~AML_UART_RECV_IRQ_MASK;
     irqc |= AML_UART_RECV_IRQ(1);
     cr |= (AML_UART_RX_INT_EN | AML_UART_RX_EN);
@@ -205,7 +205,7 @@ void init(void)
 {
     uart_setup();
 
-#if !SERIAL_TX_ONLY
+#if SERIAL_NUM_RX_CLIENTS > 0
     serial_queue_init(&rx_queue_handle, rx_queue, SERIAL_RX_DATA_REGION_CAPACITY_DRIV, rx_data);
 #endif
     serial_queue_init(&tx_queue_handle, tx_queue, SERIAL_TX_DATA_REGION_CAPACITY_DRIV, tx_data);

drivers/serial/snps/uart.c

@@ -57,8 +57,7 @@ static void tx_provide(void)
     while (reprocess) {
         char c;
 
-        while ((*REG_PTR(UART_LSR) & UART_LSR_THRE)
-               && !serial_dequeue(&tx_queue_handle, &tx_queue_handle.queue->head, &c)) {
+        while ((*REG_PTR(UART_LSR) & UART_LSR_THRE) && !serial_dequeue(&tx_queue_handle, NULL, &c)) {
             *REG_PTR(UART_THR) = c;
             transferred = true;
         }
@@ -95,7 +94,7 @@ static void rx_return(void)
         while ((*REG_PTR(UART_LSR) & UART_LSR_DR)
                && !serial_queue_full(&rx_queue_handle, rx_queue_handle.queue->tail)) {
             char c = *REG_PTR(UART_RBR);
-            int err = serial_enqueue(&rx_queue_handle, &rx_queue_handle.queue->tail, c);
+            int err = serial_enqueue(&rx_queue_handle, NULL, c);
             assert(!err);
             enqueued = true;
         }
@@ -169,7 +168,7 @@ void init(void)
     /* Enable both Recieve Data Available and Transmit Holding Register Empty IRQs. */
     *REG_PTR(UART_IER) = (UART_IER_ERBFI | UART_IER_ETBEI);
 
-#if !SERIAL_TX_ONLY
+#if SERIAL_NUM_RX_CLIENTS > 0
     serial_queue_init(&rx_queue_handle, rx_queue, SERIAL_RX_DATA_REGION_CAPACITY_DRIV, rx_data);
 #endif
     serial_queue_init(&tx_queue_handle, tx_queue, SERIAL_TX_DATA_REGION_CAPACITY_DRIV, tx_data);

drivers/serial/virtio/console.c

@@ -111,8 +111,7 @@ static void tx_provide(void)
     bool transferred = false;
     while (reprocess) {
         char c;
-        while (!virtio_avail_full_tx(&tx_virtq)
-               && !serial_dequeue(&tx_queue_handle, &tx_queue_handle.queue->head, &c)) {
+        while (!virtio_avail_full_tx(&tx_virtq) && !serial_dequeue(&tx_queue_handle, NULL, &c)) {
 
                 /* First, allocate somewhere to put the character */
             uint32_t char_idx = -1;
@@ -250,7 +249,7 @@ static void rx_return(void)
             assert(!(pkt.flags & VIRTQ_DESC_F_NEXT));
 
             uint32_t char_idx = addr - virtio_rx_char_paddr;
-            serial_enqueue(&rx_queue_handle, &rx_queue_handle.queue->tail, virtio_rx_char[char_idx]);
+            serial_enqueue(&rx_queue_handle, NULL, virtio_rx_char[char_idx]);
 
                 /* Free the packet descriptor */
             int err = ialloc_free(&rx_ialloc_desc, pkt_used.id);
@@ -417,7 +416,7 @@ void init()
 
     console_setup();
 
-#if !SERIAL_TX_ONLY
+#if SERIAL_NUM_RX_CLIENTS > 0
     serial_queue_init(&rx_queue_handle, rx_queue, SERIAL_RX_DATA_REGION_CAPACITY_DRIV, rx_data);
 #endif
     serial_queue_init(&tx_queue_handle, tx_queue, SERIAL_TX_DATA_REGION_CAPACITY_DRIV, tx_data);
@@ -442,4 +441,4 @@ void notified(microkit_channel ch)
         LOG_DRIVER_ERR("received notification on unexpected channel: %u\n", ch);
         break;
     }
-}
+}

examples/echo_server/include/serial_config/serial_config.h

@@ -10,21 +10,15 @@
 #include <sddf/serial/queue.h>
 #include <stdint.h>
 
-/* Number of clients that can be connected to the serial server. */
-#define SERIAL_NUM_CLIENTS 3
+/* Number of clients capable of transmission. */
+#define SERIAL_NUM_TX_CLIENTS 3
 
-/* Only support transmission and not receive. */
-#define SERIAL_TX_ONLY 1
+/* Number of clients capable of reception. */
+#define SERIAL_NUM_RX_CLIENTS 0
 
 /* Associate a colour with each client's output. */
 #define SERIAL_WITH_COLOUR 1
 
-/* Control character to switch input stream - ctrl \. To input character input twice. */
-#define SERIAL_SWITCH_CHAR 28
-
-/* Control character to terminate client number input. */
-#define SERIAL_TERMINATE_NUM '\r'
-
 /* Default baud rate of the uart device */
 #define UART_DEFAULT_BAUD 115200
 

examples/serial/include/serial_config/serial_config.h

@@ -10,23 +10,24 @@
 #include <sddf/serial/queue.h>
 #include <stdint.h>
 
-#define SERIAL_NUM_CLIENTS 2
+/* Number of clients capable of transmission. */
+#define SERIAL_NUM_TX_CLIENTS 2
 
-/* Only support transmission and not receive. */
-#define SERIAL_TX_ONLY 0
+/* Number of clients capable of reception. */
+#define SERIAL_NUM_RX_CLIENTS 2
 
 /* Associate a colour with each client's output. */
 #define SERIAL_WITH_COLOUR 1
 
+/* Default baud rate of the uart device */
+#define UART_DEFAULT_BAUD 115200
+
 /* Control character to switch input stream - ctrl \. To input character input twice. */
 #define SERIAL_SWITCH_CHAR 28
 
 /* Control character to terminate client number input. */
 #define SERIAL_TERMINATE_NUM '\r'
 
-/* Default baud rate of the uart device */
-#define UART_DEFAULT_BAUD 115200
-
 /* String to be printed to start console input */
 #define SERIAL_CONSOLE_BEGIN_STRING "Begin input\n"
 #define SERIAL_CONSOLE_BEGIN_STRING_LEN 12

examples/serial/serial_server.c

@@ -35,7 +35,7 @@ void notified(microkit_channel ch)
     bool reprocess = true;
     char c;
     while (reprocess) {
-        while (!serial_dequeue(&rx_queue_handle, &rx_queue_handle.queue->head, &c)) {
+        while (!serial_dequeue(&rx_queue_handle, NULL, &c)) {
             if (c == '\r') {
                 sddf_putchar_unbuffered('\\');
                 sddf_putchar_unbuffered('r');

include/sddf/serial/queue.h

@@ -62,19 +62,22 @@ static inline int serial_queue_full(serial_queue_handle_t *queue_handle, uint32_
  * @param queue_handle queue to enqueue into.
  * @param local_tail address of the tail to be incremented. This allows for clients to
  *                      enqueue multiple characters before making the changes visible.
+ *                      Leave NULL to increment shared queue tail.
  * @param character character to be enqueued.
  *
  * @return -1 when queue is empty, 0 on success.
  */
 static inline int serial_enqueue(serial_queue_handle_t *queue_handle, uint32_t *local_tail,
                                  char character)
 {
-    if (serial_queue_full(queue_handle, *local_tail)) {
+    uint32_t *tail = (local_tail == NULL) ? &queue_handle->queue->tail : local_tail;
+
+    if (serial_queue_full(queue_handle, *tail)) {
         return -1;
     }
 
-    queue_handle->data_region[*local_tail % queue_handle->capacity] = character;
-    (*local_tail)++;
+    queue_handle->data_region[*tail % queue_handle->capacity] = character;
+    (*tail)++;
 
     return 0;
 }
@@ -85,19 +88,22 @@ static inline int serial_enqueue(serial_queue_handle_t *queue_handle, uint32_t *
  * @param queue_handle queue to dequeue from.
  * @param local_head address of the head to be incremented. This allows for clients to
  *                      dequeue multiple characters before making the changes visible.
+ *                      Leave NULL to increment shared queue head.
  * @param character character to copy into.
  *
  * @return -1 when queue is empty, 0 on success.
  */
 static inline int serial_dequeue(serial_queue_handle_t *queue_handle, uint32_t *local_head,
                                  char *character)
 {
-    if (serial_queue_empty(queue_handle, *local_head)) {
+    uint32_t *head = (local_head == NULL) ? &queue_handle->queue->head : local_head;
+
+    if (serial_queue_empty(queue_handle, *head)) {
         return -1;
     }
 
-    *character = queue_handle->data_region[*local_head % queue_handle->capacity];
-    (*local_head)++;
+    *character = queue_handle->data_region[*head % queue_handle->capacity];
+    (*head)++;
 
     return 0;
 }

serial/components/virt_rx.c

@@ -21,7 +21,7 @@ char *rx_data_drv;
 char *rx_data_cli0;
 
 serial_queue_handle_t rx_queue_handle_drv;
-serial_queue_handle_t rx_queue_handle_cli[SERIAL_NUM_CLIENTS];
+serial_queue_handle_t rx_queue_handle_cli[SERIAL_NUM_RX_CLIENTS];
 
 #define MAX_CLI_BASE_10 4
 typedef enum mode {normal, switched, number} mode_t;
@@ -45,7 +45,7 @@ void rx_return(void)
     uint32_t local_tail = rx_queue_handle_cli[current_client].queue->tail;
     char c = '\0';
     while (reprocess) {
-        while (!serial_dequeue(&rx_queue_handle_drv, &rx_queue_handle_drv.queue->head, &c)) {
+        while (!serial_dequeue(&rx_queue_handle_drv, NULL, &c)) {
             switch (current_mode) {
             case normal:
                 switch (c) {
@@ -78,7 +78,7 @@ void rx_return(void)
             default:
                 if (c == SERIAL_TERMINATE_NUM) {
                     int input_number = sddf_atoi(next_client);
-                    if (input_number >= 0 && input_number < SERIAL_NUM_CLIENTS) {
+                    if (input_number >= 0 && input_number < SERIAL_NUM_RX_CLIENTS) {
                         if (transferred && serial_require_producer_signal(&rx_queue_handle_cli[current_client])) {
                             serial_update_visible_tail(&rx_queue_handle_cli[current_client], local_tail);
                             serial_cancel_producer_signal(&rx_queue_handle_cli[current_client]);