dm: refine the uart_core

Make uart_init and uart_deinit internal functions. And make
uart_set_backend/uart_release_backend cover uart_init/uart_deinit
function.

This will make mevent teardown callback adding easier for uart_core.

Tracked-On: #1877
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Acked-by: Yu Wang <yu1.wang@intel.com>

devicemodel/hw/pci/lpc.c

@@ -175,7 +175,6 @@ lpc_deinit(struct vmctx *ctx)
 		unregister_inout(&iop);
 
 		uart_release_backend(lpc_uart->uart, lpc_uart->opts);
-		uart_deinit(lpc_uart->uart);
 		uart_legacy_dealloc(unit);
 		lpc_uart->uart = NULL;
 		lpc_uart->enabled = 0;
@@ -205,23 +204,9 @@ lpc_init(struct vmctx *ctx)
 		}
 		pci_irq_reserve(lpc_uart->irq);
 
-		lpc_uart->uart = uart_init(lpc_uart_intr_assert,
-				    lpc_uart_intr_deassert, lpc_uart);
-
-		if (lpc_uart->uart < 0) {
-			uart_legacy_dealloc(unit);
-			goto init_failed;
-		}
-
-		error = uart_set_backend(lpc_uart->uart, lpc_uart->opts);
-		/*
-		 * Continue to initialize LPC UART device if opts is invalid,
-		 * and the data will be dropped by uart_write in UART DM.
-		 */
-		if (error && error != -EINVAL) {
-			fprintf(stderr, "Unable to initialize backend '%s' "
-			    "for LPC device %s\n", lpc_uart->opts, name);
-			uart_deinit(lpc_uart->uart);
+		lpc_uart->uart = uart_set_backend(lpc_uart_intr_assert, lpc_uart_intr_deassert,
+			lpc_uart, lpc_uart->opts);
+		if (lpc_uart->uart == NULL) {
 			uart_legacy_dealloc(unit);
 			goto init_failed;
 		}

devicemodel/hw/pci/uart.c

@@ -82,9 +82,6 @@ pci_uart_read(struct vmctx *ctx, int vcpu, struct pci_vdev *dev,
 static int
 pci_uart_init(struct vmctx *ctx, struct pci_vdev *dev, char *opts)
 {
-	struct uart_vdev *uart;
-	int ret;
-
 	pci_emul_alloc_bar(dev, 0, PCIBAR_IO, UART_IO_BAR_SIZE);
 	pci_lintr_request(dev);
 
@@ -93,11 +90,8 @@ pci_uart_init(struct vmctx *ctx, struct pci_vdev *dev, char *opts)
 	pci_set_cfgdata16(dev, PCIR_VENDOR, COM_VENDOR);
 	pci_set_cfgdata8(dev, PCIR_CLASS, PCIC_SIMPLECOMM);
 
-	uart = uart_init(pci_uart_intr_assert, pci_uart_intr_deassert, dev);
-	dev->arg = uart;
-
-	ret = uart_set_backend(uart, opts);
-	if (ret && ret != -EINVAL) {
+	dev->arg = uart_set_backend(pci_uart_intr_assert, pci_uart_intr_deassert, dev, opts);
+	if (dev->arg == NULL) {
 		fprintf(stderr, "Unable to initialize backend '%s' for "
 		    "pci uart at %d:%d\n", opts, dev->slot, dev->func);
 		return -1;
@@ -115,7 +109,6 @@ pci_uart_deinit(struct vmctx *ctx, struct pci_vdev *dev, char *opts)
 		return;
 
 	uart_release_backend(uart, opts);
-	uart_deinit(uart);
 }
 
 struct pci_vdev_ops pci_ops_com = {

devicemodel/hw/uart_core.c

@@ -629,7 +629,7 @@ uart_legacy_dealloc(int which)
 	uart_lres[which].inuse = false;
 }
 
-struct uart_vdev *
+static struct uart_vdev *
 uart_init(uart_intr_func_t intr_assert, uart_intr_func_t intr_deassert,
 	void *arg)
 {
@@ -650,7 +650,7 @@ uart_init(uart_intr_func_t intr_assert, uart_intr_func_t intr_deassert,
 	return uart;
 }
 
-void
+static void
 uart_deinit(struct uart_vdev *uart)
 {
 	if (uart) {
@@ -681,15 +681,19 @@ uart_tty_backend(struct uart_vdev *uart, const char *opts)
 	return retval;
 }
 
-int
-uart_set_backend(struct uart_vdev *uart, const char *opts)
+struct uart_vdev *
+uart_set_backend(uart_intr_func_t intr_assert, uart_intr_func_t intr_deassert,
+	void *arg, const char *opts)
 {
-	int retval;
+	int retval = -1;
+	struct uart_vdev *uart;
 
-	retval = -1;
+	uart = uart_init(intr_assert, intr_deassert, arg);
+	if (!uart)
+		return NULL;
 
 	if (opts == NULL)
-		return -EINVAL;
+		return uart;
 
 	if (strcmp("stdio", opts) == 0) {
 		if (!stdio_in_use) {
@@ -703,17 +707,29 @@ uart_set_backend(struct uart_vdev *uart, const char *opts)
 		retval = 0;
 	}
 
-	if (retval)
-		return -EINVAL;
+	if (retval) {
+		uart_deinit(uart);
+		return NULL;
+	}
 
 	/* Make the backend file descriptor non-blocking */
-	if (retval == 0)
 	retval = fcntl(uart->tty.fd_in, F_SETFL, O_NONBLOCK);
+	if (retval != 0)
+		goto fail_tty_backend;
 
-	if (retval == 0)
 	uart_opentty(uart);
 
-	return retval;
+	return uart;
+
+fail_tty_backend:
+	if (uart->tty.fd_in) {
+		close(uart->tty.fd_in);
+		uart->tty.fd_in = -1;
+		uart->tty.fd_out = -1;
+		uart->tty.opened = false;
+	}
+	uart_deinit(uart);
+	return NULL;
 }
 
 void
@@ -741,4 +757,6 @@ uart_release_backend(struct uart_vdev *uart, const char *opts)
 	uart->tty.fd_in = -1;
 	uart->tty.fd_out = -1;
 	uart->tty.opened = false;
+
+	uart_deinit(uart);
 }

devicemodel/include/uart_core.h

@@ -35,14 +35,12 @@
 struct uart_vdev;
 
 typedef void (*uart_intr_func_t)(void *arg);
-struct uart_vdev *uart_init(uart_intr_func_t intr_assert,
-			    uart_intr_func_t intr_deassert, void *arg);
-void uart_deinit(struct uart_vdev *uart);
-
 int	uart_legacy_alloc(int unit, int *ioaddr, int *irq);
 void	uart_legacy_dealloc(int which);
 uint8_t	uart_read(struct uart_vdev *uart, int offset);
 void	uart_write(struct uart_vdev *uart, int offset, uint8_t value);
-int	uart_set_backend(struct uart_vdev *uart, const char *opt);
+struct	uart_vdev*
+	uart_set_backend(uart_intr_func_t intr_assert, uart_intr_func_t intr_deassert,
+		void *arg, const char *opts);
 void	uart_release_backend(struct uart_vdev *uart, const char *opts);
 #endif