From: tony@atomide•com (Tony Lindgren)
To: linux-arm-kernel@lists•infradead.org
Subject: runtime check for omap-aes bus access permission (was: Re: 3.13-rc3 (commit 7ce93f3) breaks Nokia N900 DT boot)
Date: Mon, 1 Jun 2015 10:58:07 -0700 [thread overview]
Message-ID: <20150601175806.GZ30984@atomide.com> (raw)
In-Reply-To: <CAALWOA-X-Jb_2NODrPNnDgaLuYFDuxjPLHYwqRjaPz2PrqhJkA@mail.gmail.com>
* Matthijs van Duin <matthijsvanduin@gmail•com> [150530 08:24]:
> On 29 May 2015 at 17:50, Tony Lindgren <tony@atomide•com> wrote:
> > I believe some TI kernels use strongly-ordered mappings, mainline
> > kernel does not. Which kernel version are you using?
>
> Normally I periodically rebuild based on Robert C Nelson's -bone
> kernel (but with heavily customized config). I also tried a plain
> 4.1.0-rc5-bone3, the generic 4.1.0-rc5-armv7-x0 (the most
> vanilla-looking kernel I could find in my debian package list), and
> for the heck of it also the classic 3.14.43-ti-r66.
>
> In all cases I observed a synchronous bus error (dubiously reported as
> "external abort on non-linefetch (0x1818)") on an AM335x with this
> trivial test:
>
> int main() {
> int fd = open( "/dev/mem", O_RDWR | O_DSYNC );
> if( fd < 0 ) return 1;
> void *ptr = mmap( NULL, 4096, PROT_WRITE, MAP_SHARED, fd, 0x42000000 );
> if( ptr == MAP_FAILED ) return 1;
> *(volatile int *)ptr = 0;
> return 0;
> }
>
> I even considered for a moment that maybe the AM335x has some "all
> writes non-posted" thing enabled (which I think is available as a
> switch on OMAP 4/5?). It seemed unlikely, but since most of my
> exploration of interconnect behaviour was done on a DM814x, I
> double-checked by performing the same write in a baremetal test
> program (with that region configured Device-type in the MMU). As
> expected, no data abort occurred, so writes most certainly are posted.
>
> So I have trouble coming up with any explanation for this other than
> the use of strongly-ordered mappings.
>
> (Curiously BTW, omitting O_DSYNC made no difference.)
I think these kernels are missing the configuration for l3-noc
driver?
I tried it on omap4 that has l3-noc configured, and it first produces
"Unhandled fault: external abort on non-linefetch (0x1818) at 0xb6fd7000",
and the L3 interrupt only after that. So yeah, you're right, we can't
use the interrupts here. I somehow remembered we'd get only the L3
interrupt if configured.
Regards,
Tony
next prev parent reply other threads:[~2015-06-01 17:58 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20131206213613.GA19648@earth.universe>
[not found] ` <201502111339.54480@pali>
[not found] ` <CAALWOA_ngoSKjB=ZQ264Va37bBK7v41Ei45SyoYLiMdanTKnxQ@mail.gmail.com>
[not found] ` <201502112128.44852@pali>
2015-02-11 20:40 ` runtime check for omap-aes bus access permission (was: Re: 3.13-rc3 (commit 7ce93f3) breaks Nokia N900 DT boot) Nishanth Menon
2015-02-18 21:14 ` Pali Rohár
2015-05-28 7:37 ` Pali Rohár
2015-05-28 16:01 ` Tony Lindgren
2015-05-28 20:26 ` Matthijs van Duin
2015-05-28 22:24 ` Tony Lindgren
2015-05-28 22:27 ` Pali Rohár
2015-05-29 0:15 ` Tony Lindgren
2015-05-29 0:58 ` Matthijs van Duin
2015-05-29 1:35 ` Matthijs van Duin
2015-05-29 15:50 ` Tony Lindgren
2015-05-29 18:16 ` Tony Lindgren
2015-05-30 15:22 ` Matthijs van Duin
2015-06-01 17:58 ` Tony Lindgren [this message]
2015-06-01 20:32 ` Matthijs van Duin
2015-06-01 20:52 ` Tony Lindgren
2015-06-02 4:21 ` Matthijs van Duin
2015-02-19 18:20 ` Pali Rohár
2015-02-19 20:25 ` Matthijs van Duin
2015-02-19 21:10 ` Aaro Koskinen
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