From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Tue, 26 May 2009 03:31:25 +0100 (BST) Received: from [222.92.8.141] ([222.92.8.141]:57884 "EHLO lemote.com" rhost-flags-FAIL-FAIL-OK-OK) by ftp.linux-mips.org with ESMTP id S20023822AbZEZCbR (ORCPT ); Tue, 26 May 2009 03:31:17 +0100 Received: from localhost (localhost [127.0.0.1]) by lemote.com (Postfix) with ESMTP id D58D9340A3; Tue, 26 May 2009 10:26:05 +0800 (CST) X-Virus-Scanned: Debian amavisd-new at lemote.com Received: from lemote.com ([127.0.0.1]) by localhost (www.lemote.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Bcxa1bXROc6i; Tue, 26 May 2009 10:25:51 +0800 (CST) Received: from localhost.localdomain (unknown [172.16.2.66]) by lemote.com (Postfix) with ESMTP id 9BBAA340AD; Tue, 26 May 2009 10:25:50 +0800 (CST) Message-ID: <4A1B53A3.6060503@lemote.com> Date: Tue, 26 May 2009 10:27:47 +0800 From: Hongbing Hu User-Agent: Mozilla-Thunderbird 2.0.0.9 (X11/20080110) MIME-Version: 1.0 To: yanh@lemote.com CC: Atsushi Nemoto , wuzhangjin@gmail.com, linux-mips@linux-mips.org, ralf@linux-mips.org, philippe@cowpig.ca, r0bertz@gentoo.org, zhangfx@lemote.com, apatard@mandriva.com, loongson-dev@googlegroups.com, gnewsense-dev@nongnu.org, hofrat@hofr.at, liujl@lemote.com, erwan@thiscow.com Subject: Re: [loongson-PATCH-v1 22/27] Hibernation Support in mips system References: <817be0da759e19d781e98237cc70efeb33f10a40.1242855716.git.wuzhangjin@gmail.com> <20090522.220123.59650403.anemo@mba.ocn.ne.jp> <1243066003.8509.60.camel@localhost.localdomain> <20090523.213045.39168996.anemo@mba.ocn.ne.jp> <1243302188.9819.58.camel@localhost.localdomain> In-Reply-To: <1243302188.9819.58.camel@localhost.localdomain> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 22966 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: huhb@lemote.com Precedence: bulk X-list: linux-mips yanh 写道: > 在 2009-05-23六的 21:30 +0900，Atsushi Nemoto写道： > >> On Sat, 23 May 2009 16:06:43 +0800, yanh wrote: >> >>>>> +unsigned long >>>>> + saved_ra, >>>>> + saved_sp, >>>>> >> ... >> >>>>> + saved_v0, >>>>> + saved_v1; >>>>> >>>> Instead of enumerating them, I would prefer something like "struct >>>> pt_regs saved_regs" or "unsigned long saved_regs[32]". >>>> >>> This implementation is referencing the x86 platform. >>> Not all the 32 reigsters are needed to save. >>> Maybe the whole registers needed to save can still be reduced. >>> >> I did not mean save/restore all registers. I just mean using only one >> symbol (struct or array). Though the struct or array contains some >> unused members, it saves many instructions in >> swsusp_arch_{suspend,resume}. >> >> For saving N registers, (N * 2) instructions are required to save to >> individual variables, but (N + 2) instructions are required to save to >> array or struct. >> > > Yes, the struct array method is more efficient, we will change to it. > The length of registers is different between 32bit kernel and 64bit kernel. That means the file hibernate.S wiil be divided into hibernate_32.S and hibernate_64.S ? >>>>> +void save_processor_state(void) >>>>> +{ >>>>> + saved_status = read_c0_status(); >>>>> +} >>>>> >>>> No need to save/restore floating point registers? >>>> >>> the floating point registers are not used by kernel, for user part, they >>> are already saved while entering into kernel mode. >>> >> No, floating point registers are not saved on entering into kernel. >> They are saved on context switch. >> Yes, suspend to disk will freeze processes at first,and i think the process wiil save the float point regs. So there is no need to save them. > It's my mistake. But I think, if there is need to save floating point > registers, the kernel have already done for it. > What's need to save should be for the resuming parts. Those registers which are used while > in suspending path are needed to save. > > create_image() > > in_suspend = 1; > save_processor_state(); > error = swsusp_arch_suspend(); > if (error) > printk(KERN_ERR "PM: Error %d creating hibernation image\n", > error); > > when resuming this functions is executed for righ after the swsusp_arch_suspend(). > This is not a normal function return. > So the registers need to save are those damaged by swsusp_arch_suspend and what it calls. > > because this is not a normal function call, the callee saved registers can not be restored, so we need to save > it explicitly. For caller saved temporary registers, they are already saved in create_image. Are this right? > > --- >> Atsushi Nemoto >> > > > > -- --------------------------------------------------------- Hongbing,Hu (Software Department) Tel: 0512-52308631 E-mail: huhb@lemote.com MSN: [huhb04@gmail.com] JiangSu Lemote Corp. Ltd. MengLan, Yushan, Changshu, JiangSu Province, China ---------------------------------------------------------