Subject: Re: Areca RAID driver remaining items?
From: Arjan van de Ven <arjan@infradead.org>
To: erich <erich@areca.com.tw>
Cc: "\"\"Christoph Hellwig\"\"" <hch@infradead.org>,
       linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
       billion.wu@areca.com.tw, alan@lxorguk.ukuu.org.uk, akpm@osdl.org,
       oliver@neukum.org
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Date: Thu, 23 Feb 2006 13:07:32 +0100
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On Thu, 2006-02-23 at 19:51 +0800, erich wrote:
> If Linux can not assurent the contingous memory space allocating of 
> "dma_alloc_coherent" .

coherent memory is guaranteed to be in the "lower" 32 bit of memory!
So that is good news, I think you are just fine.

[Exception is that you can say that you are ok with a bigger mask for
this type of memory, but just don't do that if you're not]


> When arcmsr get a physical ccb address from areca's firmware.
> Does linux has any functions for converting of  "bus to virtual" ?

not without using pools. You would have to search the list of memory you
gave it to find that out.

(USB has a similar problem, afaik they solved it with pools)


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