From mboxrd@z Thu Jan  1 00:00:00 1970
From: Philippe Gerum <rpm@xenomai.org>
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Date: Fri, 27 Mar 2009 11:28:47 +0100
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Subject: Re: [Xenomai-help] Meaning of cache locking in /proc/xenomai/faults
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To: belatronix@domain.hid
Cc: xenomai@xenomai.org

On Fri, 2009-03-27 at 10:37 +0100, Axel Beierlein wrote:
> Philippe Gerum schrieb:
> > On Fri, 2009-03-27 at 10:00 +0100, Axel Beierlein wrote:
> >> Hello,
> >>
> >> on my MPC5200 i have the following output of /proc/xenomai/faults
> >>
> >> TRAP         CPU0
> >>    0:            0    (Data or instruction access)
> >>    1:            0    (Alignment)
> >>    2:            0    (Altivec unavailable)
> >>    3:            0    (Program check exception)
> >>    4:            0    (Machine check exception)
> >>    5:            0    (Unknown)
> >>    6:            0    (Instruction breakpoint)
> >>    7:            0    (Run mode exception)
> >>    8:            0    (Single-step exception)
> >>    9:            0    (Non-recoverable exception)
> >>   10:            0    (Software emulation)
> >>   11:            0    (Debug)
> >>   12:            0    (SPE)
> >>   13:            0    (Altivec assist)
> >>   14:  -1072753084    (Cache-locking exception)
> >>   15:            0    (Kernel FP unavailable)
> >>
> >> Now i am trying to find out what the negative Value of Cache-locking and 
> >> what this Trap general mean and when it was triggered.
> > 
> > The negative value is only the sign of an overflow. However, a cache
> > locking exception is specific to FSL_BOOKE archs. What is your kernel
> > release and exact ppc platform configuration?


You can ignore the last two counters, when 2.4.25-ppc is involved, they
contain garbage in fact; this does not have any consequences beyond that
strange output. The patch below should fix them, actually leave them
zeroed.

--- include/asm-ppc/ipipe.h~	2008-06-08 16:15:51.000000000 +0200
+++ include/asm-ppc/ipipe.h	2009-03-27 11:22:31.000000000 +0100
@@ -80,7 +80,7 @@ do {						\
 #define IPIPE_TRAP_DEBUG	11	/* Debug exception */
 #define IPIPE_TRAP_SPE		12	/* SPE exception */
 #define IPIPE_TRAP_ALTASSIST	13	/* Altivec assist exception */
-#define IPIPE_NR_FAULTS		14
+#define IPIPE_NR_FAULTS		16
 /* Pseudo-vectors used for kernel events */
 #define IPIPE_FIRST_EVENT	IPIPE_NR_FAULTS
 #define IPIPE_EVENT_SYSCALL	(IPIPE_FIRST_EVENT)

-- 
Philippe.