From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754100AbaG2Tdi (ORCPT ); Tue, 29 Jul 2014 15:33:38 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:53939 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751459AbaG2Tdg (ORCPT ); Tue, 29 Jul 2014 15:33:36 -0400 Message-ID: <53D7F6F3.9020804@ti.com> Date: Tue, 29 Jul 2014 14:33:07 -0500 From: Suman Anna User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.0 MIME-Version: 1.0 To: Ohad Ben-Cohen CC: Dave Gerlach , "linux-kernel@vger.kernel.org" , "linux-omap@vger.kernel.org" , linux-arm , Robert Tivy Subject: Re: [PATCH 2/2] remoteproc: add support to handle internal memories References: <1404836521-59637-1-git-send-email-s-anna@ti.com> <1404836521-59637-3-git-send-email-s-anna@ti.com> In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Ohad, On 07/29/2014 06:00 AM, Ohad Ben-Cohen wrote: > Hi Suman, > > On Tue, Jul 8, 2014 at 7:22 PM, Suman Anna wrote: >> A remote processor may need to load certain firmware sections into >> internal memories (eg: RAM at L1 or L2 levels) for performance or >> other reasons. > > Can you please provide as much details as you can about the scenario > you need this for? what hardware, what sections, which specific > memory, what's the use case, numbers, sizes, everything. > > I'd like to better understand the use case please. We currently have two usecases. The primary usecase is the WkupM3 processor on TI Sitara AM335x/AM437x SoCs used for suspend/resume management. This series is a dependency for the WkupM3 remoteproc driver that Dave posted [1]. More details are in section 8.1.4.6 of the AM335x TRM [2]. The program/data sections for this processor all _needs_ to be in the two internal memory RAMS (16K Unified RAM and 8K Data RAM), and there is no MMU for this processor. The current RSC_CARVEOUT and RSC_DEVMEM do not fit to describe this type of memory (we neither allocate memory through dma api nor do we need to map these into an MMU). The second usecase is for some code to be loaded into the internal memories of the DSP in existing OMAPs directly during remoteproc loading stage. These memories are accessible to the processor again without having to go through the L2MMU through which the external RAM and peripherals are accessed through. regards Suman [1] https://patchwork.kernel.org/patch/4529651/ [2] www.ti.com/lit.ug/spruh73k/spruh73k.pdf