[src/trunk]: src/sys/arch/sparc sun4v: Workaround for OpenBoot feature where ...

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

details:   https://anonhg.NetBSD.org/src/rev/24d0ef7c8f74
branches:  trunk
changeset: 344492:24d0ef7c8f74
user:      palle <palle%NetBSD.org@localhost>
date:      Fri Apr 01 20:21:45 2016 +0000

description:
sun4v: Workaround for OpenBoot feature where a 64-bit address is truncated to a 32-bit address. This happends when a write to the console (/virtual-devices@100/console@1) is done. Avoid this by using 
a static buffer that is mapped below 4GB. Thanks to Tarl Neustaedter for explaining how OpenBoot works. ok martin@

diffstat:

 sys/arch/sparc/include/openfirm.h |   3 +-
 sys/arch/sparc/sparc/openfirm.c   |  46 +++++++++++++++++++++++++++++++++++++-
 sys/arch/sparc/sparc/promlib.c    |   6 +++-
 3 files changed, 50 insertions(+), 5 deletions(-)

diffs (125 lines):

diff -r 0c6f574af07e -r 24d0ef7c8f74 sys/arch/sparc/include/openfirm.h
--- a/sys/arch/sparc/include/openfirm.h Fri Apr 01 19:59:08 2016 +0000
+++ b/sys/arch/sparc/include/openfirm.h Fri Apr 01 20:21:45 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: openfirm.h,v 1.9 2015/10/06 20:03:05 martin Exp $      */
+/*     $NetBSD: openfirm.h,v 1.10 2016/04/01 20:21:45 palle Exp $      */
 
 /*
  * Copyright (C) 1995, 1996 Wolfgang Solfrank.
@@ -61,6 +61,7 @@
 #define HDQ2CELL_LO(x) (cell_t)(x)
 #endif /* __sparc_v9__ */
 
+void   OF_init(void);
 int    OF_test(const char *);
 int    OF_test_method(int, const char *);
 void   OF_set_symbol_lookup(void (*)(void *), void (*)(void *));
diff -r 0c6f574af07e -r 24d0ef7c8f74 sys/arch/sparc/sparc/openfirm.c
--- a/sys/arch/sparc/sparc/openfirm.c   Fri Apr 01 19:59:08 2016 +0000
+++ b/sys/arch/sparc/sparc/openfirm.c   Fri Apr 01 20:21:45 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: openfirm.c,v 1.20 2015/03/27 06:10:25 nakayama Exp $   */
+/*     $NetBSD: openfirm.c,v 1.21 2016/04/01 20:21:45 palle Exp $      */
 
 /*
  * Copyright (C) 1995, 1996 Wolfgang Solfrank.
@@ -32,7 +32,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: openfirm.c,v 1.20 2015/03/27 06:10:25 nakayama Exp $");
+__KERNEL_RCSID(0, "$NetBSD: openfirm.c,v 1.21 2016/04/01 20:21:45 palle Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -44,6 +44,34 @@
 #include <sys/stdarg.h>
 #endif
 
+#ifdef SUN4V
+#ifdef __arch64__
+#define OFBOUNCE_MAXSIZE 1024
+/* 
+ * Sun4v OpenBoot is not always happy with 64-bit addresses - an example is the
+ * addr parameter in the OF_write() call which can be truncated to a 32-bit
+ * value.
+ * Avoid this behaviour by using a static buffer which is assumed to be mapped
+ * in on a 32-bit address.
+ * Use a mutex to protect access to the buffer from multiple threads.
+ * 
+ */
+kmutex_t ofcall_mtx;
+static char ofbounce[OFBOUNCE_MAXSIZE];
+#endif
+#endif
+
+void
+OF_init(void)
+{
+#ifdef SUN4V
+#ifdef __arch64__
+  KASSERT(((uint64_t)&ofbounce & 0xffffffffUL)==(uint64_t)&ofbounce);
+  mutex_init(&ofcall_mtx, MUTEX_DEFAULT, IPL_NONE);
+#endif 
+#endif
+}
+
 int
 OF_peer(int phandle)
 {
@@ -512,6 +540,15 @@
        if (len > 1024) {
                panic("OF_write(len = %d)\n", len);
        }
+#ifdef SUN4V
+#if __arch64__
+       mutex_enter(&ofcall_mtx);
+       if (len > OFBOUNCE_MAXSIZE) 
+               panic("OF_write(len = %d) exceedes bounce buffer\n", len);
+       memcpy(ofbounce, addr, len);
+       addr = ofbounce;
+#endif 
+#endif
        args.name = ADR2CELL("write");
        args.nargs = 3;
        args.nreturns = 1;
@@ -525,6 +562,11 @@
                l = args.actual;
                act += l;
        }
+#ifdef SUN4V
+#if __arch64__
+       mutex_exit(&ofcall_mtx);
+#endif
+#endif
        return act;
 }
 
diff -r 0c6f574af07e -r 24d0ef7c8f74 sys/arch/sparc/sparc/promlib.c
--- a/sys/arch/sparc/sparc/promlib.c    Fri Apr 01 19:59:08 2016 +0000
+++ b/sys/arch/sparc/sparc/promlib.c    Fri Apr 01 20:21:45 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: promlib.c,v 1.44 2014/03/26 15:55:43 christos Exp $ */
+/*     $NetBSD: promlib.c,v 1.45 2016/04/01 20:21:45 palle Exp $ */
 
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: promlib.c,v 1.44 2014/03/26 15:55:43 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: promlib.c,v 1.45 2016/04/01 20:21:45 palle Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_sparc_arch.h"
@@ -1276,6 +1276,8 @@
        node = findchosen();
        OF_getprop(node, "stdin", &promops.po_stdin, sizeof(int));
        OF_getprop(node, "stdout", &promops.po_stdout, sizeof(int));
+
+       OF_init();
 }
 
 /*