Avoid touching "locked" DARTs. While there, print something when we place

a DART in bypass mode.

ok patrick@

diff --git a/sys/arch/arm64/dev/apldart.c b/sys/arch/arm64/dev/apldart.c
index d6df9f4..96b3a06 100644 (file)
--- a/sys/arch/arm64/dev/apldart.c
+++ b/sys/arch/arm64/dev/apldart.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: apldart.c,v 1.8 2021/11/11 18:43:05 kettenis Exp $    */
+/*     $OpenBSD: apldart.c,v 1.9 2022/02/06 19:10:07 kettenis Exp $    */
 /*
  * Copyright (c) 2021 Mark Kettenis <kettenis@openbsd.org>
  *
@@ -47,6 +47,8 @@
 #define DART_ERROR             0x0040
 #define DART_ERROR_ADDR_LO     0x0050
 #define DART_ERROR_ADDR_HI     0x0054
+#define DART_CONFIG            0x0060
+#define  DART_CONFIG_LOCK              (1 << 15)
 #define DART_TCR(sid)          (0x0100 + 4 *(sid))
 #define  DART_TCR_TRANSLATE_ENABLE     (1 << 7)
 #define  DART_TCR_BYPASS_DART          (1 << 8)
@@ -194,7 +196,7 @@ apldart_attach(struct device *parent, struct device *self, void *aux)
        paddr_t pa;
        volatile uint64_t *l1;
        int ntte, nl1, nl2;
-       uint32_t params2;
+       uint32_t config, params2;
        int sid, idx;
 
        if (faa->fa_nreg < 1) {
@@ -211,17 +213,31 @@ apldart_attach(struct device *parent, struct device *self, void *aux)
 
        sc->sc_dmat = faa->fa_dmat;
 
-       printf("\n");
+       /* Skip locked DARTs for now. */
+       config = HREAD4(sc, DART_CONFIG);
+       if (config & DART_CONFIG_LOCK) {
+               printf(": locked\n");
+               return;
+       }
 
+       /*
+        * Use bypass mode if supported.  This avoids an issue with
+        * the USB3 controllers which need mappings entered into two
+        * IOMMUs, which is somewhat difficult to implement with our
+        * current kernel interfaces.
+        */
        params2 = HREAD4(sc, DART_PARAMS2);
        if (params2 & DART_PARAMS2_BYPASS_SUPPORT) {
                for (sid = 0; sid < DART_NUM_STREAMS; sid++) {
                        HWRITE4(sc, DART_TCR(sid),
                            DART_TCR_BYPASS_DART | DART_TCR_BYPASS_DAPF);
                }
+               printf(": bypass\n");
                return;
        }
 
+       printf("\n");
+
        /*
         * Skip the first page to help catching bugs where a device is
         * doing DMA to/from address zero because we didn't properly