[src/trunk]: src/sys/arch/arm/arm32 ARMv6+ supplied a write bit in the FSR so...

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

details:   https://anonhg.NetBSD.org/src/rev/2b061f68dda2
branches:  trunk
changeset: 326994:2b061f68dda2
user:      matt <matt%NetBSD.org@localhost>
date:      Tue Feb 25 09:54:33 2014 +0000

description:
ARMv6+ supplied a write bit in the FSR so use instead of reading the
instruction.

diffstat:

 sys/arch/arm/arm32/fault.c |  33 ++++++++++++++++++---------------
 1 files changed, 18 insertions(+), 15 deletions(-)

diffs (64 lines):

diff -r 183709d6cff9 -r 2b061f68dda2 sys/arch/arm/arm32/fault.c
--- a/sys/arch/arm/arm32/fault.c        Tue Feb 25 08:54:57 2014 +0000
+++ b/sys/arch/arm/arm32/fault.c        Tue Feb 25 09:54:33 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: fault.c,v 1.93 2014/01/29 18:45:21 matt Exp $  */
+/*     $NetBSD: fault.c,v 1.94 2014/02/25 09:54:33 matt Exp $  */
 
 /*
  * Copyright 2003 Wasabi Systems, Inc.
@@ -81,7 +81,7 @@
 #include "opt_kgdb.h"
 
 #include <sys/types.h>
-__KERNEL_RCSID(0, "$NetBSD: fault.c,v 1.93 2014/01/29 18:45:21 matt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: fault.c,v 1.94 2014/02/25 09:54:33 matt Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -258,8 +258,10 @@
 
        /* Get the current lwp structure */
 
-       UVMHIST_LOG(maphist, " (pc=0x%x, l=0x%x, far=0x%x, fsr=0x%x)",
-           tf->tf_pc, l, far, fsr);
+       UVMHIST_LOG(maphist, " (l=%#x, far=%#x, fsr=%#x",
+           l, far, fsr, 0);
+       UVMHIST_LOG(maphist, "  tf=%#x, pc=%#x)",
+           tf, tf->tf_pc, 0, 0);
 
        /* Data abort came from user mode? */
        bool user = (TRAP_USERMODE(tf) != 0);
@@ -400,20 +402,21 @@
        }
 
        /*
-        * We need to know whether the page should be mapped
-        * as R or R/W. The MMU does not give us the info as
-        * to whether the fault was caused by a read or a write.
+        * We need to know whether the page should be mapped as R or R/W.
+        * Before ARMv6, the MMU did not give us the info as to whether the
+        * fault was caused by a read or a write.
+        *
+        * However, we know that a permission fault can only be the result of
+        * a write to a read-only location, so we can deal with those quickly.
         *
-        * However, we know that a permission fault can only be
-        * the result of a write to a read-only location, so
-        * we can deal with those quickly.
-        *
-        * Otherwise we need to disassemble the instruction
-        * responsible to determine if it was a write.
+        * Otherwise we need to disassemble the instruction responsible to
+        * determine if it was a write.
         */
-       if (IS_PERMISSION_FAULT(fsr))
+       if (CPU_IS_ARMV6_P() || CPU_IS_ARMV7_P()) {
+               ftype = (fsr & FAULT_WRITE) ? VM_PROT_WRITE : VM_PROT_READ;
+       } else if (IS_PERMISSION_FAULT(fsr)) {
                ftype = VM_PROT_WRITE; 
-       else {
+       } else {
 #ifdef THUMB_CODE
                /* Fast track the ARM case.  */
                if (__predict_false(tf->tf_spsr & PSR_T_bit)) {