From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from penguin.netx4.com (embeddededge.com [209.113.146.155]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 9236F2BD81 for ; Tue, 19 Oct 2004 01:29:04 +1000 (EST) In-Reply-To: <41738D27.4060007@eircom.net> References: <1098072098.751.32.camel@nighteyes.localdomain> <41738D27.4060007@eircom.net> Mime-Version: 1.0 (Apple Message framework v619) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: From: Dan Malek Date: Mon, 18 Oct 2004 11:31:12 -0400 To: Conor McLoughlin Cc: linuxppc-embedded Subject: Re: Does kmalloc on MPC82xx work correctly with GFP_DMA? List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Oct 18, 2004, at 5:30 AM, Conor McLoughlin wrote: > I have been looking at the ethernet device driver (fcc_enet) for the > mpc82xx platform. This allocates buffer descriptors using kmalloc with > the GFP_DMA flag. Yes. > As far as I can see on my platform, this allocates > from the regular kernel memory (0xCxxxxxxx). As the attributes of this > block of memory are controlled by the block address translation > registers, No, the kmalloc() space is not covered by BATs (but, that isn't relevant for this discussion). > this cannot be DMA safe, can it? Yes, it is DMA safe. That's why this driver works :-) -- Dan