From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <49CCDF80.4020903@domain.hid> Date: Fri, 27 Mar 2009 15:15:28 +0100 From: Axel Beierlein MIME-Version: 1.0 References: <49CC95A4.9010702@domain.hid> <1238145958.6815.145.camel@domain.hid> <49CC9E46.3050501@domain.hid> <1238149727.6815.151.camel@domain.hid> <49CCD081.3020203@domain.hid> <1238161560.6815.187.camel@domain.hid> In-Reply-To: <1238161560.6815.187.camel@domain.hid> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] Meaning of cache locking in /proc/xenomai/faults Reply-To: belatronix@domain.hid List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Philippe Gerum , xenomai@xenomai.org Philippe Gerum schrieb: > On Fri, 2009-03-27 at 14:11 +0100, Axel Beierlein wrote: >> Philippe Gerum schrieb: >>> 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) >>> >> Thank you Philippe for your Help. >> >> By the way, can you, or someone else, point me to a message where are >> the other traps are explained or can you give me short examples for >> situations where the listed exceptions are triggered? >> For example: What is an alignment Trap and which situation can trigger >> such a fault. >> > > You probably want to have alook at the PowerPC UISA documentation: > http://download.boulder.ibm.com/ibmdl/pub/software/dw/library/es-ppcbook1.zip > > You will find common reasons for traps. Additionally, you should refer > to your core's reference manual, since it may have specifics regarding > why/when some exceptions are triggered. Alignment exception is usually > due to data placement, misaligned float ops are usual suspects, but > depending on your particular ppc core, other reasons for alignment traps > may exist (e.g. e300 cores fire this exception when using a particular > byte-zeroing instruction on cache-inhibited memory). In short, YMMV. > >> Axel Yeah! Thats it. Thanks. I find all the needed informations in the e300coreRM Manual from Freescale. Axel