From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 17 Apr 2020 10:11:20 -0700 From: Bjorn Andersson Subject: Re: [PATCH 2/3] remoteproc: Add inline coredump functionality Message-ID: <20200417171116.GE987656@yoga> References: <1587062312-4939-1-git-send-email-rishabhb@codeaurora.org> <1587062312-4939-2-git-send-email-rishabhb@codeaurora.org> <1b85229632dd44f198b3e0ff9414b458@SFHDAG7NODE2.st.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1b85229632dd44f198b3e0ff9414b458@SFHDAG7NODE2.st.com> To: Loic PALLARDY Cc: Rishabh Bhatnagar , "linux-remoteproc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "ohad@wizery.com" , "mathieu.poirier@linaro.org" , "tsoni@codeaurora.org" , "psodagud@codeaurora.org" , "sidgup@codeaurora.org" List-ID: On Fri 17 Apr 00:52 PDT 2020, Loic PALLARDY wrote: > Hi Rishabh, > > > -----Original Message----- > > From: linux-remoteproc-owner@vger.kernel.org > owner@vger.kernel.org> On Behalf Of Rishabh Bhatnagar > > Sent: jeudi 16 avril 2020 20:39 > > To: linux-remoteproc@vger.kernel.org; linux-kernel@vger.kernel.org > > Cc: bjorn.andersson@linaro.org; ohad@wizery.com; > > mathieu.poirier@linaro.org; tsoni@codeaurora.org; > > psodagud@codeaurora.org; sidgup@codeaurora.org; Rishabh Bhatnagar > > > > Subject: [PATCH 2/3] remoteproc: Add inline coredump functionality > > > > This patch adds the inline coredump functionality. The current > > coredump implementation uses vmalloc area to copy all the segments. > > But this might put a lot of strain on low memory targets as the > > firmware size sometimes is in ten's of MBs. The situation becomes > > worse if there are multiple remote processors undergoing recovery > > at the same time. This patch directly copies the device memory to > > userspace buffer and avoids extra memory usage. This requires > > recovery to be halted until data is read by userspace and free > > function is called. > > > > Signed-off-by: Rishabh Bhatnagar > > --- > > drivers/remoteproc/remoteproc_coredump.c | 130 > > +++++++++++++++++++++++++++++++ > > drivers/remoteproc/remoteproc_internal.h | 23 +++++- > > include/linux/remoteproc.h | 2 + > > 3 files changed, 153 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/remoteproc/remoteproc_coredump.c > > b/drivers/remoteproc/remoteproc_coredump.c > > index 9de0467..888b7dec91 100644 > > --- a/drivers/remoteproc/remoteproc_coredump.c > > +++ b/drivers/remoteproc/remoteproc_coredump.c > > @@ -12,6 +12,84 @@ > > #include > > #include "remoteproc_internal.h" > > > > +static void rproc_free_dump(void *data) > > +{ > > + struct rproc_coredump_state *dump_state = data; > > + > > + complete(&dump_state->dump_done); > > +} > > + > > +static unsigned long resolve_addr(loff_t user_offset, > > + struct list_head *segments, > > + unsigned long *data_left) > > +{ > > + struct rproc_dump_segment *segment; > > + > > + list_for_each_entry(segment, segments, node) { > > + if (user_offset >= segment->size) > > + user_offset -= segment->size; > > + else > > + break; > > + } > > + > > + if (&segment->node == segments) { > > + *data_left = 0; > > + return 0; > > + } > > + > > + *data_left = segment->size - user_offset; > > + > > + return segment->da + user_offset; > > +} > > + > > +static ssize_t rproc_read_dump(char *buffer, loff_t offset, size_t count, > > + void *data, size_t header_size) > > +{ > > + void *device_mem; > > + size_t data_left, copy_size, bytes_left = count; > > + unsigned long addr; > > + struct rproc_coredump_state *dump_state = data; > > + struct rproc *rproc = dump_state->rproc; > > + void *elfcore = dump_state->header; > > + > > + /* Copy the header first */ > > + if (offset < header_size) { > > + copy_size = header_size - offset; > > + copy_size = min(copy_size, bytes_left); > > + > > + memcpy(buffer, elfcore + offset, copy_size); > > + offset += copy_size; > > + bytes_left -= copy_size; > > + buffer += copy_size; > > + } > > + > > + while (bytes_left) { > > + addr = resolve_addr(offset - header_size, > > + &rproc->dump_segments, &data_left); > > + /* EOF check */ > > + if (data_left == 0) { > > + pr_info("Ramdump complete %lld bytes read", > > offset); > > + break; > > + } > > + > > + copy_size = min_t(size_t, bytes_left, data_left); > > + > > + device_mem = rproc->ops->da_to_va(rproc, addr, > > copy_size); > > + if (!device_mem) { > > + pr_err("Address:%lx with size %zd out of remoteproc > > carveout\n", > > + addr, copy_size); > > + return -ENOMEM; > > + } > > + memcpy(buffer, device_mem, copy_size); > > + > > + offset += copy_size; > > + buffer += copy_size; > > + bytes_left -= copy_size; > > + } > > + > > + return count - bytes_left; > > +} > > + > > static void create_elf_header(void *data, int phnum, struct rproc *rproc) > > { > > struct elf32_phdr *phdr; > > @@ -55,6 +133,58 @@ static void create_elf_header(void *data, int phnum, > > struct rproc *rproc) > > } > > > > /** > > + * rproc_inline_coredump() - perform synchronized coredump > > + * @rproc: rproc handle > > + * > > + * This function will generate an ELF header for the registered segments > > + * and create a devcoredump device associated with rproc. This function > > + * directly copies the segments from device memory to userspace. The > > + * recovery is stalled until the enitire coredump is read. This approach > Typo entire -> entire > > + * avoids using extra vmalloc memory(which can be really large). > > + */ > > +void rproc_inline_coredump(struct rproc *rproc) > > +{ > > + struct rproc_dump_segment *segment; > > + struct elf32_phdr *phdr; > > + struct elf32_hdr *ehdr; > > + struct rproc_coredump_state *dump_state; > > + size_t header_size; > > + void *data; > > + int phnum = 0; > > + > > + if (list_empty(&rproc->dump_segments)) > > + return; > > + > > + header_size = sizeof(*ehdr); > > + list_for_each_entry(segment, &rproc->dump_segments, node) { > > + header_size += sizeof(*phdr); > > + > > + phnum++; > > + } > > + > > + data = vmalloc(header_size); > > + if (!data) > > + return; > > + > > + ehdr = data; > > + create_elf_header(data, phnum, rproc); > > + > > + dump_state = kzalloc(sizeof(*dump_state), GFP_KERNEL); > > + dump_state->rproc = rproc; > > + dump_state->header = data; > > + init_completion(&dump_state->dump_done); > > + > > + dev_coredumpm(&rproc->dev, NULL, dump_state, header_size, > > GFP_KERNEL, > > + rproc_read_dump, rproc_free_dump); > > + > > + /* Wait until the dump is read and free is called */ > > + wait_for_completion(&dump_state->dump_done); > > Maybe good to add a timeout with value programmable via debugfs? > devcoredump provides a timeout already, although not configurable today. I believe this is sufficient, but a mentioning in the comment would be useful. Regards, Bjorn From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4AA2C2D0EF for ; Fri, 17 Apr 2020 17:11:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8CC8A2076D for ; Fri, 17 Apr 2020 17:11:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="qqkD47l8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728454AbgDQRLV (ORCPT ); Fri, 17 Apr 2020 13:11:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60540 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728098AbgDQRLU (ORCPT ); Fri, 17 Apr 2020 13:11:20 -0400 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A2C3EC061A0C for ; Fri, 17 Apr 2020 10:11:20 -0700 (PDT) Received: by mail-pg1-x541.google.com with SMTP id 2so1391972pgp.11 for ; Fri, 17 Apr 2020 10:11:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=MwZ5r02j5DDu60b1Yf9fovCXLqb5sheQ6pTSo/D8kaw=; b=qqkD47l8byHNt7HvcF2YWHI8Ln1OLaurWVoh8ZPaayTt3kJndV4E6vQECtjPzxFfSW X7VJJs7Vk775xW4hvTcgl22hvwy/7iauD3LJcPpkWR5VXnAoPkk8eqqEXKXBOXGzSD4L FEcy3aKLz8b5lt3JdCyLOLIQOuVDjGfyxfQNLRB4uco6lzfWJjRpSXle+6COvQd9GGPK GnqcdTMAMYCycNXQdX3ugEUBcvwd2s5p9wyKqgoo4caxt2KLoYpIqkxap6uZZfR19ijO AdF0H/bRlEkoh4fGxGwC8pSAMeKN1Mc8c42RcIvV9bkluBMJYUwC4Mtao9DYbS8dzpyC h6Hg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=MwZ5r02j5DDu60b1Yf9fovCXLqb5sheQ6pTSo/D8kaw=; b=PTQVhFcR4Ny1JempuKV5TqQxflveBt9aCLbSFMeaLqZxnp4vCDtkYwHE1X6LoKjMOk bX/9hg4Dh4NJwM3E5M4tDzwB85CCYmbRIKZPcETGJahoD8fpvOgUzNdzAOTt/UbqA+M+ oOvSrF0hNJrBhf674oakjY3e7o9teqQseUv6xUCMn4E8wxf4ESoUklUQGCvIZCNIv6Og hz+TP/cv5qp9hOaTXPelRfuPGcUiERn2Lmyk62FUQPu177aHoxYqNedRk1fafm6ioKPf xc6H1M/yBZch0EZwieGtsXlAp8L3p6/nBnprDfYDSeZbsvhMdJUgN6sVnKepPR/wunLx y3nw== X-Gm-Message-State: AGi0PuYxu853+Ta1RWcLZLiFZ7oW+j7hFgOjKk1wT3D38APgvV1VKK1U PIFeLYVTAHYrSknxkJqqNaUOVA== X-Google-Smtp-Source: APiQypIulTHG+RBBZXvWiEQM4Jv4FTSexWl0Z/vnVRTL12zNnihOWSGrnncl1pym0ocnUvjzdqetOw== X-Received: by 2002:a63:fc45:: with SMTP id r5mr2738667pgk.440.1587143479915; Fri, 17 Apr 2020 10:11:19 -0700 (PDT) Received: from yoga (104-188-17-28.lightspeed.sndgca.sbcglobal.net. [104.188.17.28]) by smtp.gmail.com with ESMTPSA id o99sm6186906pjo.8.2020.04.17.10.11.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Apr 2020 10:11:19 -0700 (PDT) Date: Fri, 17 Apr 2020 10:11:16 -0700 From: Bjorn Andersson To: Loic PALLARDY Cc: Rishabh Bhatnagar , "linux-remoteproc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "ohad@wizery.com" , "mathieu.poirier@linaro.org" , "tsoni@codeaurora.org" , "psodagud@codeaurora.org" , "sidgup@codeaurora.org" Subject: Re: [PATCH 2/3] remoteproc: Add inline coredump functionality Message-ID: <20200417171116.GE987656@yoga> References: <1587062312-4939-1-git-send-email-rishabhb@codeaurora.org> <1587062312-4939-2-git-send-email-rishabhb@codeaurora.org> <1b85229632dd44f198b3e0ff9414b458@SFHDAG7NODE2.st.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1b85229632dd44f198b3e0ff9414b458@SFHDAG7NODE2.st.com> Sender: linux-remoteproc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-remoteproc@vger.kernel.org Message-ID: <20200417171116.xqH_r9blT8AaKlouEx3-btM1HWyj03-hXyXlP2NrcvE@z> On Fri 17 Apr 00:52 PDT 2020, Loic PALLARDY wrote: > Hi Rishabh, > > > -----Original Message----- > > From: linux-remoteproc-owner@vger.kernel.org > owner@vger.kernel.org> On Behalf Of Rishabh Bhatnagar > > Sent: jeudi 16 avril 2020 20:39 > > To: linux-remoteproc@vger.kernel.org; linux-kernel@vger.kernel.org > > Cc: bjorn.andersson@linaro.org; ohad@wizery.com; > > mathieu.poirier@linaro.org; tsoni@codeaurora.org; > > psodagud@codeaurora.org; sidgup@codeaurora.org; Rishabh Bhatnagar > > > > Subject: [PATCH 2/3] remoteproc: Add inline coredump functionality > > > > This patch adds the inline coredump functionality. The current > > coredump implementation uses vmalloc area to copy all the segments. > > But this might put a lot of strain on low memory targets as the > > firmware size sometimes is in ten's of MBs. The situation becomes > > worse if there are multiple remote processors undergoing recovery > > at the same time. This patch directly copies the device memory to > > userspace buffer and avoids extra memory usage. This requires > > recovery to be halted until data is read by userspace and free > > function is called. > > > > Signed-off-by: Rishabh Bhatnagar > > --- > > drivers/remoteproc/remoteproc_coredump.c | 130 > > +++++++++++++++++++++++++++++++ > > drivers/remoteproc/remoteproc_internal.h | 23 +++++- > > include/linux/remoteproc.h | 2 + > > 3 files changed, 153 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/remoteproc/remoteproc_coredump.c > > b/drivers/remoteproc/remoteproc_coredump.c > > index 9de0467..888b7dec91 100644 > > --- a/drivers/remoteproc/remoteproc_coredump.c > > +++ b/drivers/remoteproc/remoteproc_coredump.c > > @@ -12,6 +12,84 @@ > > #include > > #include "remoteproc_internal.h" > > > > +static void rproc_free_dump(void *data) > > +{ > > + struct rproc_coredump_state *dump_state = data; > > + > > + complete(&dump_state->dump_done); > > +} > > + > > +static unsigned long resolve_addr(loff_t user_offset, > > + struct list_head *segments, > > + unsigned long *data_left) > > +{ > > + struct rproc_dump_segment *segment; > > + > > + list_for_each_entry(segment, segments, node) { > > + if (user_offset >= segment->size) > > + user_offset -= segment->size; > > + else > > + break; > > + } > > + > > + if (&segment->node == segments) { > > + *data_left = 0; > > + return 0; > > + } > > + > > + *data_left = segment->size - user_offset; > > + > > + return segment->da + user_offset; > > +} > > + > > +static ssize_t rproc_read_dump(char *buffer, loff_t offset, size_t count, > > + void *data, size_t header_size) > > +{ > > + void *device_mem; > > + size_t data_left, copy_size, bytes_left = count; > > + unsigned long addr; > > + struct rproc_coredump_state *dump_state = data; > > + struct rproc *rproc = dump_state->rproc; > > + void *elfcore = dump_state->header; > > + > > + /* Copy the header first */ > > + if (offset < header_size) { > > + copy_size = header_size - offset; > > + copy_size = min(copy_size, bytes_left); > > + > > + memcpy(buffer, elfcore + offset, copy_size); > > + offset += copy_size; > > + bytes_left -= copy_size; > > + buffer += copy_size; > > + } > > + > > + while (bytes_left) { > > + addr = resolve_addr(offset - header_size, > > + &rproc->dump_segments, &data_left); > > + /* EOF check */ > > + if (data_left == 0) { > > + pr_info("Ramdump complete %lld bytes read", > > offset); > > + break; > > + } > > + > > + copy_size = min_t(size_t, bytes_left, data_left); > > + > > + device_mem = rproc->ops->da_to_va(rproc, addr, > > copy_size); > > + if (!device_mem) { > > + pr_err("Address:%lx with size %zd out of remoteproc > > carveout\n", > > + addr, copy_size); > > + return -ENOMEM; > > + } > > + memcpy(buffer, device_mem, copy_size); > > + > > + offset += copy_size; > > + buffer += copy_size; > > + bytes_left -= copy_size; > > + } > > + > > + return count - bytes_left; > > +} > > + > > static void create_elf_header(void *data, int phnum, struct rproc *rproc) > > { > > struct elf32_phdr *phdr; > > @@ -55,6 +133,58 @@ static void create_elf_header(void *data, int phnum, > > struct rproc *rproc) > > } > > > > /** > > + * rproc_inline_coredump() - perform synchronized coredump > > + * @rproc: rproc handle > > + * > > + * This function will generate an ELF header for the registered segments > > + * and create a devcoredump device associated with rproc. This function > > + * directly copies the segments from device memory to userspace. The > > + * recovery is stalled until the enitire coredump is read. This approach > Typo entire -> entire > > + * avoids using extra vmalloc memory(which can be really large). > > + */ > > +void rproc_inline_coredump(struct rproc *rproc) > > +{ > > + struct rproc_dump_segment *segment; > > + struct elf32_phdr *phdr; > > + struct elf32_hdr *ehdr; > > + struct rproc_coredump_state *dump_state; > > + size_t header_size; > > + void *data; > > + int phnum = 0; > > + > > + if (list_empty(&rproc->dump_segments)) > > + return; > > + > > + header_size = sizeof(*ehdr); > > + list_for_each_entry(segment, &rproc->dump_segments, node) { > > + header_size += sizeof(*phdr); > > + > > + phnum++; > > + } > > + > > + data = vmalloc(header_size); > > + if (!data) > > + return; > > + > > + ehdr = data; > > + create_elf_header(data, phnum, rproc); > > + > > + dump_state = kzalloc(sizeof(*dump_state), GFP_KERNEL); > > + dump_state->rproc = rproc; > > + dump_state->header = data; > > + init_completion(&dump_state->dump_done); > > + > > + dev_coredumpm(&rproc->dev, NULL, dump_state, header_size, > > GFP_KERNEL, > > + rproc_read_dump, rproc_free_dump); > > + > > + /* Wait until the dump is read and free is called */ > > + wait_for_completion(&dump_state->dump_done); > > Maybe good to add a timeout with value programmable via debugfs? > devcoredump provides a timeout already, although not configurable today. I believe this is sufficient, but a mentioning in the comment would be useful. Regards, Bjorn