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From: Scott Wood <scottwood@freescale.com>
To: "wilbur.chan" <wilbur512@gmail.com>
Cc: linuxppc-dev@ozlabs.org
Subject: Re: Can't write value into memory ?(E500 V2)
Date: Thu, 27 Aug 2009 10:59:07 -0500	[thread overview]
Message-ID: <4A96AD4B.1010204@freescale.com> (raw)
In-Reply-To: <e997b7420908270853i7d4058e1p8ddcfcf8df18486e@mail.gmail.com>

wilbur.chan wrote:
> I am using a SMP E500 v2, and I want CPU0 to write some value to a 
> physical address, and  wait for CPU1 to read from it.

Is this under Linux (it is a Linux mailing list...)?  If so, there are 
better ways of communicating that don't involve clobbering random memory 
and overlapping userspace TLB mappings.

> However, it seemed failed to communicate between CPUs by DRAM..  CPU1 
> can not read
>  
> the correct value from the address where CPU1 wrote to.

Do both cores have a mapping with the M bit (memory coherence required) set?

-Scott

  reply	other threads:[~2009-08-27 15:58 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-08-26 14:39 Can't write value into memory ?(E500 V2) wilbur.chan
2009-08-26 19:20 ` Scott Wood
2009-08-27 15:53   ` wilbur.chan
2009-08-27 15:59     ` Scott Wood [this message]
2009-08-27 16:27       ` wilbur.chan
2009-08-27 16:34         ` Scott Wood

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