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RFH: What are the semantics of writeb() and friends?

To: <linux-mips@linux-mips.org>
Subject: RFH: What are the semantics of writeb() and friends?
From: "David Daney" <ddaney@avtrex.com>
Date: Thu, 30 Jun 2005 22:22:17 -0700
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Thread-topic: What are the semantics of writeb() and friends?
In this thread:
 
 
I relate the problems I was having with the Intel e100 driver on a new 2.6.12 port to a 4ke based system.
 
My new question is:  What are the semantics of writeb(), writel() et al.?  I would assume that the effects of these must be in the same order that they were issued, and that any hardware write back queue cannot combine or merge them in any way.  Is that correct?
 
 
A second question I have is:  What is the difference in the semantics of wbflush() and wmb()?  For my CPU they both evaluate to the same thing (the 'sync' instruction).  So for my own sake I could use either, but depending on the situation I assume that one would be used over the other.
 
Thanks,
David Daney.
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