From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from de01egw01.freescale.net (de01egw01.freescale.net [192.88.165.102]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "de01egw01.freescale.net", Issuer "Thawte Premium Server CA" (verified OK)) by ozlabs.org (Postfix) with ESMTP id D7D17DDE16 for ; Wed, 18 Jul 2007 02:04:27 +1000 (EST) Message-ID: <469CE80A.5080204@freescale.com> Date: Tue, 17 Jul 2007 11:02:18 -0500 From: Scott Wood MIME-Version: 1.0 To: suresh suresh Subject: Re: Linuxppc-embedded Digest, Vol 35, Issue 33 References: <469B9825.6070507@freescale.com> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Cc: linuxppc-embedded@ozlabs.org, Siva Prasad List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , suresh suresh wrote: > MPC8280 has internal memory space which contains Dualport(Dp) RAM. In the > DpRAM we allocate some tables and these has to store pointer of the buffers > which are allocated in external memory. Core will use this pointer to > access > the buffers, basically these buffers are used for DMA. > > Using IMMR register we can get physical address of the internal memory. Now > can I store the address return by the kmalloc() function? or I should > convert it into physical? Yes, you need to convert it to physical. As I said earlier, use the DMA mapping API (described in Documentation/DMA-mapping.txt) to do so. Specifically, look at the dma_map_single() function. -Scott