Introduce variables to deal with bit layout differences in the UFSTAT

register.  Use 32-bit reads and writes to access the URXH and UTXH
registers.  They're documented as 32-bit registers in the Exynos 4 and
Exynos 5 User Manuals and accessing URXH with an 8-bit read triggers a
fault on Apple's M1 SoC.

ok patrick@

diff --git a/sys/dev/fdt/exuart.c b/sys/dev/fdt/exuart.c
index 0ea1381..df6ec34 100644 (file)
--- a/sys/dev/fdt/exuart.c
+++ b/sys/dev/fdt/exuart.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: exuart.c,v 1.5 2021/02/11 23:53:42 patrick Exp $ */
+/* $OpenBSD: exuart.c,v 1.6 2021/02/14 13:39:24 kettenis Exp $ */
 /*
  * Copyright (c) 2005 Dale Rahn <drahn@motorola.com>
  *
@@ -55,6 +55,11 @@ struct exuart_softc {
        struct tty      *sc_tty;
        struct timeout  sc_diag_tmo;
        struct timeout  sc_dtr_tmo;
+
+       uint32_t        sc_rx_fifo_cnt_mask;
+       uint32_t        sc_rx_fifo_full;
+       uint32_t        sc_tx_fifo_full;
+
        int             sc_fifo;
        int             sc_overflows;
        int             sc_floods;
@@ -125,6 +130,10 @@ bus_addr_t exuartconsaddr;
 tcflag_t       exuartconscflag = TTYDEF_CFLAG;
 int            exuartdefaultrate = B115200;
 
+uint32_t       exuart_rx_fifo_cnt_mask;
+uint32_t       exuart_rx_fifo_full;
+uint32_t       exuart_tx_fifo_full;
+
 struct cdevsw exuartdev =
        cdev_tty_init(3/*XXX NEXUART */ ,exuart);               /* 12: serial port */
 
@@ -151,6 +160,10 @@ exuart_init_cons(void)
        if (fdt_get_reg(node, 0, &reg))
                return;
 
+       exuart_rx_fifo_cnt_mask = EXUART_UFSTAT_RX_FIFO_CNT_MASK;
+       exuart_rx_fifo_full = EXUART_UFSTAT_RX_FIFO_FULL;
+       exuart_tx_fifo_full = EXUART_UFSTAT_TX_FIFO_FULL;
+
        exuartcnattach(fdt_cons_bs_tag, reg.addr, B115200, TTYDEF_CFLAG);
 }
 
@@ -190,6 +203,10 @@ exuart_attach(struct device *parent, struct device *self, void *aux)
                printf(": console");
        }
 
+       sc->sc_rx_fifo_cnt_mask = EXUART_UFSTAT_RX_FIFO_CNT_MASK;
+       sc->sc_rx_fifo_full = EXUART_UFSTAT_RX_FIFO_FULL;
+       sc->sc_tx_fifo_full = EXUART_UFSTAT_TX_FIFO_FULL;
+
        /* Mask and clear interrupts. */
        bus_space_write_4(sc->sc_iot, sc->sc_ioh, EXUART_UINTM,
            EXUART_UINTM_RXD | EXUART_UINTM_ERROR |
@@ -239,8 +256,8 @@ exuart_intr(void *arg)
                p = sc->sc_ibufp;
 
                while (bus_space_read_4(iot, ioh, EXUART_UFSTAT) &
-                   (EXUART_UFSTAT_RX_FIFO_CNT_MASK|EXUART_UFSTAT_RX_FIFO_FULL)) {
-                       c = bus_space_read_1(iot, ioh, EXUART_URXH);
+                   (sc->sc_rx_fifo_cnt_mask | sc->sc_rx_fifo_full)) {
+                       c = bus_space_read_4(iot, ioh, EXUART_URXH);
                        if (p >= sc->sc_ibufend) {
                                sc->sc_floods++;
                                if (sc->sc_errors++ == 0)
@@ -278,7 +295,7 @@ exuart_intr(void *arg)
        p = sc->sc_ibufp;
 
        while(ISSET(bus_space_read_2(iot, ioh, EXUART_USR2), EXUART_SR2_RDR)) {
-               c = bus_space_read_1(iot, ioh, EXUART_URXH);
+               c = bus_space_read_4(iot, ioh, EXUART_URXH);
                if (p >= sc->sc_ibufend) {
                        sc->sc_floods++;
                        if (sc->sc_errors++ == 0)
@@ -422,7 +439,7 @@ exuart_start(struct tty *tp)
 
                n = q_to_b(&tp->t_outq, buffer, sizeof buffer);
                for (i = 0; i < n; i++)
-                       bus_space_write_1(iot, ioh, EXUART_UTXH, buffer[i]);
+                       bus_space_write_4(iot, ioh, EXUART_UTXH, buffer[i]);
                bzero(buffer, n);
        }
 
@@ -921,9 +938,9 @@ exuartcngetc(dev_t dev)
        while((bus_space_read_4(exuartconsiot, exuartconsioh, EXUART_UTRSTAT) &
            EXUART_UTRSTAT_RXBREADY) == 0 &&
              (bus_space_read_4(exuartconsiot, exuartconsioh, EXUART_UFSTAT) &
-           (EXUART_UFSTAT_RX_FIFO_CNT_MASK|EXUART_UFSTAT_RX_FIFO_FULL)) == 0)
+           (exuart_rx_fifo_cnt_mask | exuart_rx_fifo_full)) == 0)
                ;
-       c = bus_space_read_1(exuartconsiot, exuartconsioh, EXUART_URXH);
+       c = bus_space_read_4(exuartconsiot, exuartconsioh, EXUART_URXH);
        splx(s);
        return c;
 }
@@ -934,9 +951,9 @@ exuartcnputc(dev_t dev, int c)
        int s;
        s = splhigh();
        while (bus_space_read_4(exuartconsiot, exuartconsioh, EXUART_UFSTAT) &
-          EXUART_UFSTAT_TX_FIFO_FULL)
+          exuart_tx_fifo_full)
                ;
-       bus_space_write_1(exuartconsiot, exuartconsioh, EXUART_UTXH, c);
+       bus_space_write_4(exuartconsiot, exuartconsioh, EXUART_UTXH, c);
        splx(s);
 }