[src/trunk]: src/sys/arch/aarch64/aarch64 add support userspace tagged addres...

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

details:   https://anonhg.NetBSD.org/src/rev/e54c1e72b7a9
branches:  trunk
changeset: 745372:e54c1e72b7a9
user:      ryo <ryo%NetBSD.org@localhost>
date:      Sat Feb 29 21:36:03 2020 +0000

description:
add support userspace tagged address for aarch64 (experimental)

'sysctl machdep.tagged_address' to set/clear TCR_EL1.TBI0 to enable/disable address tagging.
with 'machdep.tagged_address=1', some syscalls may cause problems?

diffstat:

 sys/arch/aarch64/aarch64/aarch64_machdep.c |  65 +++++++++++++++++++++++++++++-
 1 files changed, 63 insertions(+), 2 deletions(-)

diffs (93 lines):

diff -r 03269f6f0056 -r e54c1e72b7a9 sys/arch/aarch64/aarch64/aarch64_machdep.c
--- a/sys/arch/aarch64/aarch64/aarch64_machdep.c        Sat Feb 29 21:34:37 2020 +0000
+++ b/sys/arch/aarch64/aarch64/aarch64_machdep.c        Sat Feb 29 21:36:03 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: aarch64_machdep.c,v 1.39 2020/02/29 21:09:11 ryo Exp $ */
+/* $NetBSD: aarch64_machdep.c,v 1.40 2020/02/29 21:36:03 ryo Exp $ */
 
 /*-
  * Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(1, "$NetBSD: aarch64_machdep.c,v 1.39 2020/02/29 21:09:11 ryo Exp $");
+__KERNEL_RCSID(1, "$NetBSD: aarch64_machdep.c,v 1.40 2020/02/29 21:36:03 ryo Exp $");
 
 #include "opt_arm_debug.h"
 #include "opt_ddb.h"
@@ -50,6 +50,7 @@
 #include <sys/msgbuf.h>
 #include <sys/reboot.h>
 #include <sys/sysctl.h>
+#include <sys/xcall.h>
 
 #include <dev/mm.h>
 
@@ -397,6 +398,66 @@
        return (vaddr_t)tf;
 }
 
+/*
+ * machine dependent system variables.
+ */
+static xcfunc_t
+set_user_tagged_address(void *arg1, void *arg2)
+{
+       uint64_t enable = PTRTOUINT64(arg1);
+       uint64_t tcr = reg_tcr_el1_read();
+       if (enable)
+               tcr |= TCR_TBI0;
+       else
+               tcr &= ~TCR_TBI0;
+       reg_tcr_el1_write(tcr);
+
+       return 0;
+}
+
+static int
+sysctl_machdep_tagged_address(SYSCTLFN_ARGS)
+{
+       struct sysctlnode node;
+       int error, cur, val;
+       uint64_t tcr;
+
+       tcr = reg_tcr_el1_read();
+       cur = val = (tcr & TCR_TBI0) ? 1 : 0;
+
+       node = *rnode;
+       node.sysctl_data = &val;
+       error = sysctl_lookup(SYSCTLFN_CALL(&node));
+       if (error || newp == NULL)
+               return error;
+       if (val < 0 || val > 1)
+               return EINVAL;
+
+       if (cur != val) {
+               uint64_t where = xc_broadcast(0,
+                   (xcfunc_t)set_user_tagged_address, UINT64TOPTR(val), NULL);
+               xc_wait(where);
+       }
+
+       return 0;
+}
+
+SYSCTL_SETUP(sysctl_machdep_setup, "sysctl machdep subtree setup")
+{
+       sysctl_createv(clog, 0, NULL, NULL,
+           CTLFLAG_PERMANENT,
+           CTLTYPE_NODE, "machdep", NULL,
+           NULL, 0, NULL, 0,
+           CTL_MACHDEP, CTL_EOL);
+
+       sysctl_createv(clog, 0, NULL, NULL,
+           CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
+           CTLTYPE_INT, "tagged_address",
+           SYSCTL_DESCR("top byte ignored in the address calculation"),
+           sysctl_machdep_tagged_address, 0, NULL, 0,
+           CTL_MACHDEP, CTL_CREATE, CTL_EOL);
+}
+
 void
 parse_mi_bootargs(char *args)
 {