From owner-freebsd-hackers Thu Nov 23 22:22:31 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from web111.yahoomail.com (web111.mail.yahoo.com [205.180.60.81]) by hub.freebsd.org (Postfix) with SMTP id 87B2D37B479 for ; Thu, 23 Nov 2000 22:22:29 -0800 (PST) Received: (qmail 1646 invoked by uid 60001); 24 Nov 2000 06:22:29 -0000 Message-ID: <20001124062229.1645.qmail@web111.yahoomail.com> Received: from [164.164.56.2] by web111.yahoomail.com; Thu, 23 Nov 2000 22:22:29 PST Date: Thu, 23 Nov 2000 22:22:29 -0800 (PST) From: Mohan Krishna P Subject: DMA to user process address space!!! To: hackers@FreeBSD.ORG Cc: pmk@sasi.com MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG AFAMUG, all user processes are allocated from the virtual memory. so DMA to that doesn't make sense. but is there some way, i can let the kernel know i am DMAing to an address location and hence keep it in main memory until some x seconds?? here is why we need this. we are writing software for a multi-port switch. it can be used in both managed and unmanaged modes. in managed mode, switch is connected to host through PCI interface. all packets that can't be switched are sent to host. with cach such packet, switch passes information like the source port of the packet, it's priority level, whether the packet is tagged or not etc. in normal operation, driver discards this information and sends the packet to ether_input(). for testing purpose, we would like to have user-level process, which receives packets bypassing the ip stack(it isn't freeBSD way of doing things, but this is only for testing) and verifies the information. if the above thing can't be done, then we will have to move the user-process functionality to driver. Thanks, mohan __________________________________________________ Do You Yahoo!? Yahoo! Shopping - Thousands of Stores. Millions of Products. http://shopping.yahoo.com/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message