[src/trunk]: src/sys/arch/arm/samsung Make this driver MPSAFE

[jmcneill <jmcneill%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/1007a2ba8fe2
branches:  trunk
changeset: 433382:1007a2ba8fe2
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Tue Sep 11 10:05:31 2018 +0000

description:
Make this driver MPSAFE

diffstat:

 sys/arch/arm/samsung/exynos_uart.c |  97 +++++++++++++++++++++----------------
 1 files changed, 56 insertions(+), 41 deletions(-)

diffs (206 lines):

diff -r cfd24720686c -r 1007a2ba8fe2 sys/arch/arm/samsung/exynos_uart.c
--- a/sys/arch/arm/samsung/exynos_uart.c        Tue Sep 11 08:05:18 2018 +0000
+++ b/sys/arch/arm/samsung/exynos_uart.c        Tue Sep 11 10:05:31 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: exynos_uart.c,v 1.1 2018/07/05 13:11:58 jmcneill Exp $ */
+/* $NetBSD: exynos_uart.c,v 1.2 2018/09/11 10:05:31 jmcneill Exp $ */
 
 /*-
  * Copyright (c) 2013-2018 The NetBSD Foundation, Inc.
@@ -33,7 +33,7 @@
 
 #include <sys/cdefs.h>
 
-__KERNEL_RCSID(1, "$NetBSD: exynos_uart.c,v 1.1 2018/07/05 13:11:58 jmcneill Exp $");
+__KERNEL_RCSID(1, "$NetBSD: exynos_uart.c,v 1.2 2018/09/11 10:05:31 jmcneill Exp $");
 
 #define cn_trap()                      \
        do {                            \
@@ -77,6 +77,7 @@
        device_t sc_dev;
        bus_space_tag_t sc_bst;
        bus_space_handle_t sc_bsh;
+       kmutex_t sc_lock;
        u_int sc_freq;
        void *sc_ih;
 
@@ -186,6 +187,7 @@
 
        sc->sc_dev = self;
        sc->sc_bst = faa->faa_bst;
+       mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_HIGH);
        sc->sc_console = is_console;
        if (is_console) {
                sc->sc_bsh = exynos_uart_cnsc.sc_bsh;
@@ -259,13 +261,13 @@
 exynos_uart_cngetc(dev_t dev)
 {
        struct exynos_uart_softc * const sc = &exynos_uart_cnsc;
-       uint32_t status;
+       uint32_t ufstat;
        int s, c;
 
        s = splserial();
 
-       status = RD4(sc, SSCOM_UTRSTAT);
-       if ((status & UTRSTAT_RXREADY) == 0) {
+       ufstat = RD4(sc, SSCOM_UFSTAT);
+       if (__SHIFTOUT(ufstat, UFSTAT_RXCOUNT) == 0) {
                splx(s);
                return -1;
        }
@@ -334,6 +336,8 @@
                return EBUSY;
        }
 
+       mutex_enter(&sc->sc_lock);
+
        if ((tp->t_state & TS_ISOPEN) == 0 && tp->t_wopen == 0) {
                tp->t_dev = dev;
                ttychars(tp);
@@ -354,6 +358,8 @@
        /* Enable RX and error interrupts */
        WR4(sc, SSCOM_UINTM, ~0u & ~(UINT_RXD|UINT_ERROR));
 
+       mutex_exit(&sc->sc_lock);
+
        return tp->t_linesw->l_open(dev, tp);
 }
 
@@ -364,12 +370,16 @@
            device_lookup_private(&exuart_cd, minor(dev));
        struct tty *tp = sc->sc_tty;
 
+       mutex_enter(&sc->sc_lock);
+
        tp->t_linesw->l_close(tp, flag);
        ttyclose(tp);
 
        /* Disable interrupts */
        WR4(sc, SSCOM_UINTM, ~0u);
 
+       mutex_exit(&sc->sc_lock);
+
        return 0;
 }
 
@@ -447,8 +457,6 @@
        }
        tp->t_state |= TS_BUSY;
 
-       splx(s);
-
        for (brem = q_to_b(&tp->t_outq, sc->sc_buf, sizeof(sc->sc_buf));
             brem > 0;
             brem--, p++) {
@@ -459,7 +467,6 @@
                    SSCOM_UTXH, *p);
        }
 
-       s = spltty();
        tp->t_state &= ~TS_BUSY;
        if (ttypull(tp)) {
                tp->t_state |= TS_TIMEOUT;
@@ -473,47 +480,51 @@
 {
        struct exynos_uart_softc *sc = tp->t_sc;
 
-       if (tp->t_ospeed == t->c_ospeed &&
-           tp->t_cflag == t->c_cflag)
-               return 0;
+       mutex_enter(&sc->sc_lock);
 
-       uint32_t ulcon = 0, ubrdiv;
-       switch (ISSET(t->c_cflag, CSIZE)) {
-       case CS5:
-               ulcon |= ULCON_LENGTH_5;
-               break;
-       case CS6:
-               ulcon |= ULCON_LENGTH_6;
-               break;
-       case CS7:
-               ulcon |= ULCON_LENGTH_7;
-               break;
-       case CS8:
-               ulcon |= ULCON_LENGTH_8;
-               break;
+       if (tp->t_cflag != t->c_cflag) {
+               uint32_t ulcon = 0;
+               switch (ISSET(t->c_cflag, CSIZE)) {
+               case CS5:
+                       ulcon |= ULCON_LENGTH_5;
+                       break;
+               case CS6:
+                       ulcon |= ULCON_LENGTH_6;
+                       break;
+               case CS7:
+                       ulcon |= ULCON_LENGTH_7;
+                       break;
+               case CS8:
+                       ulcon |= ULCON_LENGTH_8;
+                       break;
+               }
+               switch (ISSET(t->c_cflag, PARENB|PARODD)) {
+               case PARENB|PARODD:
+                       ulcon |= ULCON_PARITY_ODD;
+                       break;
+               case PARENB:
+                       ulcon |= ULCON_PARITY_EVEN;
+                       break;
+               default:
+                       ulcon |= ULCON_PARITY_NONE;
+                       break;
+               }
+               if (ISSET(t->c_cflag, CSTOPB))
+                       ulcon |= ULCON_STOP;
+               WR4(sc, SSCOM_ULCON, ulcon);
        }
-       switch (ISSET(t->c_cflag, PARENB|PARODD)) {
-       case PARENB|PARODD:
-               ulcon |= ULCON_PARITY_ODD;
-               break;
-       case PARENB:
-               ulcon |= ULCON_PARITY_EVEN;
-               break;
-       default:
-               ulcon |= ULCON_PARITY_NONE;
-               break;
+
+       if (tp->t_ospeed != t->c_ospeed) {
+               const uint32_t ubrdiv = (sc->sc_freq / 16) / t->c_ospeed - 1;
+               WR4(sc, SSCOM_UBRDIV, ubrdiv);
        }
-       if (ISSET(t->c_cflag, CSTOPB))
-               ulcon |= ULCON_STOP;
-       WR4(sc, SSCOM_ULCON, ulcon);
-
-       ubrdiv = (sc->sc_freq / 16) / t->c_ospeed - 1;
-       WR4(sc, SSCOM_UBRDIV, ubrdiv);
 
        tp->t_ispeed = t->c_ispeed;
        tp->t_ospeed = t->c_ospeed;
        tp->t_cflag = t->c_cflag;
 
+       mutex_exit(&sc->sc_lock);
+
        return 0;
 }
 
@@ -524,6 +535,8 @@
        struct tty *tp = sc->sc_tty;
        uint32_t uintp, uerstat, ufstat, c;
 
+       mutex_enter(&sc->sc_lock);
+
        uintp = RD4(sc, SSCOM_UINTP);
 
        for (;;) {
@@ -551,6 +564,8 @@
 
        WR4(sc, SSCOM_UINTP, uintp);
 
+       mutex_exit(&sc->sc_lock);
+
        return 1;
 }