Index: sparc64/include/bus.h
===================================================================
RCS file: /home/ncvs/src/sys/sparc64/include/bus.h,v
retrieving revision 1.26
diff -u -r1.26 bus.h
--- sparc64/include/bus.h	2003/05/30 20:40:33	1.26
+++ sparc64/include/bus.h	2003/06/12 23:39:21
@@ -820,6 +820,38 @@
 	    bus_space_write_stream_8(t, h1, o1, bus_space_read_8(t, h2, o2));
 }
 
+static __inline uint8_t
+bus_space_readms_1(bus_space_tag_t t, bus_space_handle_t h, bus_size_t o)
+{
+
+	__BUS_DEBUG_ACCESS(h, o, "read", 1);
+	return (lduba_ms((caddr_t)(h + o), bus_type_asi[t->bst_type]));
+}
+
+static __inline uint16_t
+bus_space_readms_2(bus_space_tag_t t, bus_space_handle_t h, bus_size_t o)
+{
+
+	__BUS_DEBUG_ACCESS(h, o, "readms", 2);
+	return (lduha_ms((caddr_t)(h + o), bus_type_asi[t->bst_type]));
+}
+
+static __inline uint32_t
+bus_space_readms_4(bus_space_tag_t t, bus_space_handle_t h, bus_size_t o)
+{
+
+	__BUS_DEBUG_ACCESS(h, o, "readms", 4);
+	return (lduwa_ms((caddr_t)(h + o), bus_type_asi[t->bst_type]));
+}
+
+static __inline uint64_t
+bus_space_readms_8(bus_space_tag_t t, bus_space_handle_t h, bus_size_t o)
+{
+
+	__BUS_DEBUG_ACCESS(h, o, "readms", 8);
+	return (ldxa_ms((caddr_t)(h + o), bus_type_asi[t->bst_type]));
+}
+
 /* Back-compat functions for old ISA drivers */
 extern bus_space_tag_t isa_io_bt;
 extern bus_space_handle_t isa_io_hdl;
Index: sparc64/include/cpu.h
===================================================================
RCS file: /home/ncvs/src/sys/sparc64/include/cpu.h,v
retrieving revision 1.10
diff -u -r1.10 cpu.h
--- sparc64/include/cpu.h	2002/07/28 01:01:14	1.10
+++ sparc64/include/cpu.h	2003/06/12 23:39:21
@@ -77,6 +77,8 @@
 extern	char btext[];
 extern	char etext[];
 
+extern volatile int de_expected, de_received;
+
 void	fork_trampoline(void);
 
 static __inline u_int64_t
Index: sparc64/include/cpufunc.h
===================================================================
RCS file: /home/ncvs/src/sys/sparc64/include/cpufunc.h,v
retrieving revision 1.16
diff -u -r1.16 cpufunc.h
--- sparc64/include/cpufunc.h	2003/04/06 17:05:26	1.16
+++ sparc64/include/cpufunc.h	2003/06/12 23:39:21
@@ -102,6 +102,24 @@
 LDNC_GEN(u_int, lduwa);
 LDNC_GEN(u_long, ldxa);
 
+#define LDMS_GEN(tp, o)							\
+	static __inline tp						\
+	o ## _ms(caddr_t va, int asi)					\
+	{								\
+		tp r;							\
+		__asm __volatile("wr %2, 0, %%asi\n"			\
+		    " membar #Sync\n"					\
+		    #o " [%1] %%asi, %0\n"				\
+		    " membar #Sync\n"					\
+		    : "=r" (r) : "r" (va), "r" (asi));			\
+		return (r);						\
+	}
+
+LDMS_GEN(u_char, lduba);
+LDMS_GEN(u_short, lduha);
+LDMS_GEN(u_int, lduwa);
+LDMS_GEN(u_long, ldxa);
+
 #define	LD_GENERIC(va, asi, op, type) ({				\
 	type __r;							\
 	__asm __volatile(#op " [%1] %2, %0"				\
Index: sparc64/pci/psycho.c
===================================================================
RCS file: /home/ncvs/src/sys/sparc64/pci/psycho.c,v
retrieving revision 1.35
diff -u -r1.35 psycho.c
--- sparc64/pci/psycho.c	2003/05/30 20:48:05	1.35
+++ sparc64/pci/psycho.c	2003/06/12 23:39:23
@@ -56,6 +56,7 @@
 #include <machine/nexusvar.h>
 #include <machine/ofw_upa.h>
 #include <machine/resource.h>
+#include <machine/cpu.h>
 
 #include <sys/rman.h>
 
@@ -929,33 +930,40 @@
 	bus_space_handle_t bh;
 	u_long offset = 0;
 	u_int32_t r, devid;
-	int i;
+	int i, der;
 
-	/*
-	 * The psycho bridge does not tolerate accesses to unconfigured PCI
-	 * devices' or function's config space, so look up the device in the
-	 * firmware device tree first, and if it is not present, return a value
-	 * that will make the detection code think that there is no device here.
-	 * This is ugly...
-	 */
-	if (reg == 0 && ofw_pci_find_node(bus, slot, func) == 0)
-		return (0xffffffff);
 	sc = (struct psycho_softc *)device_get_softc(dev);
 	offset = PSYCHO_CONF_OFF(bus, slot, func, reg);
 	bh = sc->sc_bh[PCI_CS_CONFIG];
+#ifdef PSYCHO_DEBUG
+	printf("psycho_read_config expecting data error: %d.%d.%d: 0x%x\n",
+	    bus, slot, func, reg);
+#endif
+	de_expected = 1;
+	de_received = 0;
 	switch (width) {
 	case 1:
-		r = bus_space_read_1(sc->sc_cfgt, bh, offset);
+		r = bus_space_readms_1(sc->sc_cfgt, bh, offset);
 		break;
 	case 2:
-		r = bus_space_read_2(sc->sc_cfgt, bh, offset);
+		r = bus_space_readms_2(sc->sc_cfgt, bh, offset);
 		break;
 	case 4:
-		r = bus_space_read_4(sc->sc_cfgt, bh, offset);
+		r = bus_space_readms_4(sc->sc_cfgt, bh, offset);
 		break;
 	default:
 		panic("psycho_read_config: bad width");
 	}
+	der = de_received;
+	de_received = de_expected = 0;
+	if (der)
+		r = -1;
+
+#ifdef PSYCHO_DEBUG
+	printf("psycho_read_config after data error: received: %d, r: 0x%x\n",
+	    der, r);
+#endif
+
 	if (reg == PCIR_INTPIN && r == 0) {
 		/* Check for DQT_BAD_INTPIN quirk. */
 		devid = psycho_read_config(dev, bus, slot, func,
Index: sparc64/sparc64/trap.c
===================================================================
RCS file: /home/ncvs/src/sys/sparc64/sparc64/trap.c,v
retrieving revision 1.62
diff -u -r1.62 trap.c
--- sparc64/sparc64/trap.c	2003/05/04 07:21:04	1.62
+++ sparc64/sparc64/trap.c	2003/06/12 23:39:24
@@ -219,6 +219,8 @@
 SYSCTL_INT(_debug, OID_AUTO, debugger_on_signal, CTLFLAG_RW,
     &debugger_on_signal, 0, "");
 
+volatile int de_expected, de_received;
+
 void
 trap(struct trapframe *tf)
 {
@@ -328,6 +330,22 @@
 				}
 			}
 			error = 1;	
+			break;
+		case T_DATA_ERROR:
+			printf("trap data error received.\n");
+#define MEMBARSYNC_INST	((u_int32_t)0x8143e040)
+			if (de_expected) {
+				de_received = 1;
+				/*
+				 * XXX - we need to check that tf->tpc is
+				 * pointing to MEMBARSYNC_INST
+				 */
+				tf->tf_tnpc = tf->tf_tpc + 4;
+				error = 0;
+				break;
+			}
+#undef MEMBARSYNC_INST
+			error = 1;
 			break;
 		default:
 			error = 1;