From patchwork Tue Jul 28 23:08:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rishabh Bhatnagar X-Patchwork-Id: 11690051 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A077C14B7 for ; Tue, 28 Jul 2020 23:08:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C020207FC for ; Tue, 28 Jul 2020 23:08:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="fn8zRKIE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729819AbgG1XIv (ORCPT ); Tue, 28 Jul 2020 19:08:51 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:17887 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730110AbgG1XIm (ORCPT ); Tue, 28 Jul 2020 19:08:42 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1595977721; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=TO8JX6qnJDlsSqQ9mywPrX6pIPHbZlNOf2xgMjimCJY=; b=fn8zRKIEm59fcdhpPImj2xiHRuREoJGUW+WzJ3ali3Vf/Fz28tDPIcHJUVKXgG71ECuH1Cqe vBQp0Wlnd/J/382PRLw+TySHQ/mQ2R/mrDHfaiSRfF+ps3jozo+C1vki2pr4SI8qUpITjiiQ MgT+TVSlj0KCuZkGZoaGdcHf93M= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyI4ZWZiZiIsICJsaW51eC1yZW1vdGVwcm9jQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n12.prod.us-west-2.postgun.com with SMTP id 5f20afe998acebb4e93f3564 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 28 Jul 2020 23:08:25 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 8E36DC433CA; Tue, 28 Jul 2020 23:08:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-caf-mail-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=2.0 tests=ALL_TRUSTED,SPF_NONE, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from rishabhb-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: rishabhb) by smtp.codeaurora.org (Postfix) with ESMTPSA id 33051C433C6; Tue, 28 Jul 2020 23:08:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 33051C433C6 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=rishabhb@codeaurora.org From: Rishabh Bhatnagar To: linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org Cc: bjorn.andersson@linaro.org, mathieu.poirier@linaro.org, tsoni@codeaurora.org, psodagud@codeaurora.org, sidgup@codeaurora.org, Rishabh Bhatnagar Subject: [PATCH 1/2] remoteproc: Move coredump entry from debugfs to sysfs. Date: Tue, 28 Jul 2020 16:08:16 -0700 Message-Id: <1595977697-15389-2-git-send-email-rishabhb@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1595977697-15389-1-git-send-email-rishabhb@codeaurora.org> References: <1595977697-15389-1-git-send-email-rishabhb@codeaurora.org> Sender: linux-remoteproc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-remoteproc@vger.kernel.org Expose coredump configuration from sysfs instead of debugfs. In some operating systems access to debugfs might be limited. This restricts user from selecting the coredump configuration at all, hence move this interface to sysfs. Signed-off-by: Rishabh Bhatnagar --- Documentation/ABI/testing/sysfs-class-remoteproc | 40 +++++++++++ drivers/remoteproc/remoteproc_debugfs.c | 90 ------------------------ drivers/remoteproc/remoteproc_sysfs.c | 64 +++++++++++++++++ 3 files changed, 104 insertions(+), 90 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-class-remoteproc b/Documentation/ABI/testing/sysfs-class-remoteproc index 36094fb..812582a 100644 --- a/Documentation/ABI/testing/sysfs-class-remoteproc +++ b/Documentation/ABI/testing/sysfs-class-remoteproc @@ -58,3 +58,43 @@ Description: Remote processor name Reports the name of the remote processor. This can be used by userspace in exactly identifying a remote processor and ease up the usage in modifying the 'firmware' or 'state' files. + +What: /sys/class/remoteproc/.../coredump +Date: July 2020 +Contact: Rishabh Bhatnagar +Description: Remote processor coredump configuration + + Reports the coredump configuration of the remote processor, + which will be one of: + + "default" + "inline" + "disabled" + + "default" means when the remote processor's coredump is + collected it will be copied to a separate buffer and that + buffer is exposed to userspace. + + "inline" means when the remote processor's coredump is + collected userspace will directly read from the remote + processor's device memory. Extra buffer will not be used to + copy the dump. Also recovery process will not proceed until + all data is read by usersapce. + + "disabled" means no dump will be collected. + + Writing this file controls the coredump configuration of the + remote processor. The following configurations can be written: + + "default" + "inline" + "disable" + + Writing "default" will change the coredump configuration to + default option. + + Writing "inline" will change the coredump configuration to + inline. + + Writing "disable" will disable the coredump collection for + that remoteproc. diff --git a/drivers/remoteproc/remoteproc_debugfs.c b/drivers/remoteproc/remoteproc_debugfs.c index 2e3b3e2..732770e 100644 --- a/drivers/remoteproc/remoteproc_debugfs.c +++ b/drivers/remoteproc/remoteproc_debugfs.c @@ -28,94 +28,6 @@ static struct dentry *rproc_dbg; /* - * A coredump-configuration-to-string lookup table, for exposing a - * human readable configuration via debugfs. Always keep in sync with - * enum rproc_coredump_mechanism - */ -static const char * const rproc_coredump_str[] = { - [RPROC_COREDUMP_DEFAULT] = "default", - [RPROC_COREDUMP_INLINE] = "inline", - [RPROC_COREDUMP_DISABLED] = "disabled", -}; - -/* Expose the current coredump configuration via debugfs */ -static ssize_t rproc_coredump_read(struct file *filp, char __user *userbuf, - size_t count, loff_t *ppos) -{ - struct rproc *rproc = filp->private_data; - char buf[20]; - int len; - - len = scnprintf(buf, sizeof(buf), "%s\n", - rproc_coredump_str[rproc->dump_conf]); - - return simple_read_from_buffer(userbuf, count, ppos, buf, len); -} - -/* - * By writing to the 'coredump' debugfs entry, we control the behavior of the - * coredump mechanism dynamically. The default value of this entry is "default". - * - * The 'coredump' debugfs entry supports these commands: - * - * default: This is the default coredump mechanism. When the remoteproc - * crashes the entire coredump will be copied to a separate buffer - * and exposed to userspace. - * - * inline: The coredump will not be copied to a separate buffer and the - * recovery process will have to wait until data is read by - * userspace. But this avoid usage of extra memory. - * - * disabled: This will disable coredump. Recovery will proceed without - * collecting any dump. - */ -static ssize_t rproc_coredump_write(struct file *filp, - const char __user *user_buf, size_t count, - loff_t *ppos) -{ - struct rproc *rproc = filp->private_data; - int ret, err = 0; - char buf[20]; - - if (count > sizeof(buf)) - return -EINVAL; - - ret = copy_from_user(buf, user_buf, count); - if (ret) - return -EFAULT; - - /* remove end of line */ - if (buf[count - 1] == '\n') - buf[count - 1] = '\0'; - - if (rproc->state == RPROC_CRASHED) { - dev_err(&rproc->dev, "can't change coredump configuration\n"); - err = -EBUSY; - goto out; - } - - if (!strncmp(buf, "disable", count)) { - rproc->dump_conf = RPROC_COREDUMP_DISABLED; - } else if (!strncmp(buf, "inline", count)) { - rproc->dump_conf = RPROC_COREDUMP_INLINE; - } else if (!strncmp(buf, "default", count)) { - rproc->dump_conf = RPROC_COREDUMP_DEFAULT; - } else { - dev_err(&rproc->dev, "Invalid coredump configuration\n"); - err = -EINVAL; - } -out: - return err ? err : count; -} - -static const struct file_operations rproc_coredump_fops = { - .read = rproc_coredump_read, - .write = rproc_coredump_write, - .open = simple_open, - .llseek = generic_file_llseek, -}; - -/* * Some remote processors may support dumping trace logs into a shared * memory buffer. We expose this trace buffer using debugfs, so users * can easily tell what's going on remotely. @@ -425,8 +337,6 @@ void rproc_create_debug_dir(struct rproc *rproc) rproc, &rproc_rsc_table_fops); debugfs_create_file("carveout_memories", 0400, rproc->dbg_dir, rproc, &rproc_carveouts_fops); - debugfs_create_file("coredump", 0600, rproc->dbg_dir, - rproc, &rproc_coredump_fops); } void __init rproc_init_debugfs(void) diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c index eea514c..40949a0 100644 --- a/drivers/remoteproc/remoteproc_sysfs.c +++ b/drivers/remoteproc/remoteproc_sysfs.c @@ -10,6 +10,69 @@ #define to_rproc(d) container_of(d, struct rproc, dev) +/* + * A coredump-configuration-to-string lookup table, for exposing a + * human readable configuration via sysfs. Always keep in sync with + * enum rproc_coredump_mechanism + */ +static const char * const rproc_coredump_str[] = { + [RPROC_COREDUMP_DEFAULT] = "default", + [RPROC_COREDUMP_INLINE] = "inline", + [RPROC_COREDUMP_DISABLED] = "disabled", +}; + +/* Expose the current coredump configuration via debugfs */ +static ssize_t coredump_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct rproc *rproc = to_rproc(dev); + + return sprintf(buf, "%s\n", rproc_coredump_str[rproc->dump_conf]); +} + +/* + * By writing to the 'coredump' sysfs entry, we control the behavior of the + * coredump mechanism dynamically. The default value of this entry is "default". + * + * The 'coredump' sysfs entry supports these commands: + * + * default: This is the default coredump mechanism. When the remoteproc + * crashes the entire coredump will be copied to a separate buffer + * and exposed to userspace. + * + * inline: The coredump will not be copied to a separate buffer and the + * recovery process will have to wait until data is read by + * userspace. But this avoid usage of extra memory. + * + * disabled: This will disable coredump. Recovery will proceed without + * collecting any dump. + */ +static ssize_t coredump_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct rproc *rproc = to_rproc(dev); + + if (rproc->state == RPROC_CRASHED) { + dev_err(&rproc->dev, "can't change coredump configuration\n"); + return -EBUSY; + } + + if (sysfs_streq(buf, "disable")) { + rproc->dump_conf = RPROC_COREDUMP_DISABLED; + } else if (sysfs_streq(buf, "inline")) { + rproc->dump_conf = RPROC_COREDUMP_INLINE; + } else if (sysfs_streq(buf, "default")) { + rproc->dump_conf = RPROC_COREDUMP_DEFAULT; + } else { + dev_err(&rproc->dev, "Invalid coredump configuration\n"); + return -EINVAL; + } + + return count; +} +static DEVICE_ATTR_RW(coredump); + /* Expose the loaded / running firmware name via sysfs */ static ssize_t firmware_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -138,6 +201,7 @@ static ssize_t name_show(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR_RO(name); static struct attribute *rproc_attrs[] = { + &dev_attr_coredump.attr, &dev_attr_firmware.attr, &dev_attr_state.attr, &dev_attr_name.attr, From patchwork Tue Jul 28 23:08:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rishabh Bhatnagar X-Patchwork-Id: 11690047 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 65EFB14DD for ; Tue, 28 Jul 2020 23:08:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E2822074F for ; Tue, 28 Jul 2020 23:08:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="ALxbZUdj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729918AbgG1XIh (ORCPT ); Tue, 28 Jul 2020 19:08:37 -0400 Received: from mail29.static.mailgun.info ([104.130.122.29]:24164 "EHLO mail29.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729597AbgG1XIg (ORCPT ); Tue, 28 Jul 2020 19:08:36 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1595977715; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=0QJhT2AZCDG6FsNDABfmZCqFbYWXnKYJTT5/9e1DdMk=; b=ALxbZUdjf2KeJ/MmJ5q8gYo7qFPcpUFIe6Zkuuj7q5AjGGGgDYsR9ja+z2qioWXqOW9gPBf/ q47Ib7WAcjJB4OYZ4qtor80IZuaTFoNF4QEfLd2q6JfbEyxS/M1+lIWTLp4NWuv7utMdXjO6 boYXWvB9Sh96qdPc2btkvlpn0/w= X-Mailgun-Sending-Ip: 104.130.122.29 X-Mailgun-Sid: WyI4ZWZiZiIsICJsaW51eC1yZW1vdGVwcm9jQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n13.prod.us-west-2.postgun.com with SMTP id 5f20afeb98acebb4e93f3865 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 28 Jul 2020 23:08:27 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id C70F3C433C6; Tue, 28 Jul 2020 23:08:26 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-caf-mail-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=2.0 tests=ALL_TRUSTED,SPF_NONE, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from rishabhb-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: rishabhb) by smtp.codeaurora.org (Postfix) with ESMTPSA id B21D7C433CB; Tue, 28 Jul 2020 23:08:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org B21D7C433CB Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=rishabhb@codeaurora.org From: Rishabh Bhatnagar To: linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org Cc: bjorn.andersson@linaro.org, mathieu.poirier@linaro.org, tsoni@codeaurora.org, psodagud@codeaurora.org, sidgup@codeaurora.org, Rishabh Bhatnagar Subject: [PATCH 2/2] remoteproc: Move recovery debugfs entry to sysfs Date: Tue, 28 Jul 2020 16:08:17 -0700 Message-Id: <1595977697-15389-3-git-send-email-rishabhb@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1595977697-15389-1-git-send-email-rishabhb@codeaurora.org> References: <1595977697-15389-1-git-send-email-rishabhb@codeaurora.org> Sender: linux-remoteproc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-remoteproc@vger.kernel.org Expose recovery mechanism through sysfs rather than exposing through debugfs. Some operating systems may limit access to debugfs through access policies. This restricts user access to recovery mechanism, hence move it to sysfs. Signed-off-by: Rishabh Bhatnagar --- Documentation/ABI/testing/sysfs-class-remoteproc | 36 +++++++++++ drivers/remoteproc/remoteproc_debugfs.c | 77 ------------------------ drivers/remoteproc/remoteproc_sysfs.c | 57 ++++++++++++++++++ 3 files changed, 93 insertions(+), 77 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-class-remoteproc b/Documentation/ABI/testing/sysfs-class-remoteproc index 812582a..16c5267 100644 --- a/Documentation/ABI/testing/sysfs-class-remoteproc +++ b/Documentation/ABI/testing/sysfs-class-remoteproc @@ -98,3 +98,39 @@ Description: Remote processor coredump configuration Writing "disable" will disable the coredump collection for that remoteproc. + +What: /sys/class/remoteproc/.../recovery +Date: July 2020 +Contact: Rishabh Bhatnagar +Description: Remote processor recovery mechanism + + Reports the recovery mechanism of the remote processor, + which will be one of: + + "enabled" + "disabled" + + "enabled" means, the remote processor will be automatically + recovered whenever it crashes. Moreover, if the remote + processor crashes while recovery is disabled, it will + be automatically recovered too as soon as recovery is enabled. + + "disabled" means, a remote processor will remain in a crashed + state if it crashes. This is useful for debugging purposes; + without it, debugging a crash is substantially harder. + + Writing this file controls the recovery mechanism of the + remote processor. The following options can be written: + + "enabled" + "disabled" + "recover" + + Writing "enabled" will enable recovery and recover the remote + processor if its crashed. + + Writing "disabled" will disable recovery and if crashed the + remote processor will remain in crashed state. + + Writing "recover" will trigger an immediate recovery if the + remote processor is in crashed state. diff --git a/drivers/remoteproc/remoteproc_debugfs.c b/drivers/remoteproc/remoteproc_debugfs.c index 732770e..71194a0 100644 --- a/drivers/remoteproc/remoteproc_debugfs.c +++ b/drivers/remoteproc/remoteproc_debugfs.c @@ -84,81 +84,6 @@ static const struct file_operations rproc_name_ops = { .llseek = generic_file_llseek, }; -/* expose recovery flag via debugfs */ -static ssize_t rproc_recovery_read(struct file *filp, char __user *userbuf, - size_t count, loff_t *ppos) -{ - struct rproc *rproc = filp->private_data; - char *buf = rproc->recovery_disabled ? "disabled\n" : "enabled\n"; - - return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf)); -} - -/* - * By writing to the 'recovery' debugfs entry, we control the behavior of the - * recovery mechanism dynamically. The default value of this entry is "enabled". - * - * The 'recovery' debugfs entry supports these commands: - * - * enabled: When enabled, the remote processor will be automatically - * recovered whenever it crashes. Moreover, if the remote - * processor crashes while recovery is disabled, it will - * be automatically recovered too as soon as recovery is enabled. - * - * disabled: When disabled, a remote processor will remain in a crashed - * state if it crashes. This is useful for debugging purposes; - * without it, debugging a crash is substantially harder. - * - * recover: This function will trigger an immediate recovery if the - * remote processor is in a crashed state, without changing - * or checking the recovery state (enabled/disabled). - * This is useful during debugging sessions, when one expects - * additional crashes to happen after enabling recovery. In this - * case, enabling recovery will make it hard to debug subsequent - * crashes, so it's recommended to keep recovery disabled, and - * instead use the "recover" command as needed. - */ -static ssize_t -rproc_recovery_write(struct file *filp, const char __user *user_buf, - size_t count, loff_t *ppos) -{ - struct rproc *rproc = filp->private_data; - char buf[10]; - int ret; - - if (count < 1 || count > sizeof(buf)) - return -EINVAL; - - ret = copy_from_user(buf, user_buf, count); - if (ret) - return -EFAULT; - - /* remove end of line */ - if (buf[count - 1] == '\n') - buf[count - 1] = '\0'; - - if (!strncmp(buf, "enabled", count)) { - /* change the flag and begin the recovery process if needed */ - rproc->recovery_disabled = false; - rproc_trigger_recovery(rproc); - } else if (!strncmp(buf, "disabled", count)) { - rproc->recovery_disabled = true; - } else if (!strncmp(buf, "recover", count)) { - /* begin the recovery process without changing the flag */ - rproc_trigger_recovery(rproc); - } else { - return -EINVAL; - } - - return count; -} - -static const struct file_operations rproc_recovery_ops = { - .read = rproc_recovery_read, - .write = rproc_recovery_write, - .open = simple_open, - .llseek = generic_file_llseek, -}; /* expose the crash trigger via debugfs */ static ssize_t @@ -329,8 +254,6 @@ void rproc_create_debug_dir(struct rproc *rproc) debugfs_create_file("name", 0400, rproc->dbg_dir, rproc, &rproc_name_ops); - debugfs_create_file("recovery", 0600, rproc->dbg_dir, - rproc, &rproc_recovery_ops); debugfs_create_file("crash", 0200, rproc->dbg_dir, rproc, &rproc_crash_ops); debugfs_create_file("resource_table", 0400, rproc->dbg_dir, diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c index 40949a0..49b846e 100644 --- a/drivers/remoteproc/remoteproc_sysfs.c +++ b/drivers/remoteproc/remoteproc_sysfs.c @@ -10,6 +10,62 @@ #define to_rproc(d) container_of(d, struct rproc, dev) +/* expose recovery flag via sysfs */ +static ssize_t recovery_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct rproc *rproc = to_rproc(dev); + + return sprintf(buf, "%s", rproc->recovery_disabled ? "disabled\n" : "enabled\n"); +} + +/* + * By writing to the 'recovery' sysfs entry, we control the behavior of the + * recovery mechanism dynamically. The default value of this entry is "enabled". + * + * The 'recovery' sysfs entry supports these commands: + * + * enabled: When enabled, the remote processor will be automatically + * recovered whenever it crashes. Moreover, if the remote + * processor crashes while recovery is disabled, it will + * be automatically recovered too as soon as recovery is enabled. + * + * disabled: When disabled, a remote processor will remain in a crashed + * state if it crashes. This is useful for debugging purposes; + * without it, debugging a crash is substantially harder. + * + * recover: This function will trigger an immediate recovery if the + * remote processor is in a crashed state, without changing + * or checking the recovery state (enabled/disabled). + * This is useful during debugging sessions, when one expects + * additional crashes to happen after enabling recovery. In this + * case, enabling recovery will make it hard to debug subsequent + * crashes, so it's recommended to keep recovery disabled, and + * instead use the "recover" command as needed. + */ +static ssize_t recovery_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct rproc *rproc = to_rproc(dev); + + if (sysfs_streq(buf, "enabled")) { + /* change the flag and begin the recovery process if needed */ + rproc->recovery_disabled = false; + rproc_trigger_recovery(rproc); + } else if (sysfs_streq(buf, "disabled")) { + rproc->recovery_disabled = true; + } else if (sysfs_streq(buf, "recover")) { + /* begin the recovery process without changing the flag */ + rproc_trigger_recovery(rproc); + } else { + return -EINVAL; + } + + return count; +} +static DEVICE_ATTR_RW(recovery); + /* * A coredump-configuration-to-string lookup table, for exposing a * human readable configuration via sysfs. Always keep in sync with @@ -201,6 +257,7 @@ static ssize_t name_show(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR_RO(name); static struct attribute *rproc_attrs[] = { + &dev_attr_recovery.attr, &dev_attr_coredump.attr, &dev_attr_firmware.attr, &dev_attr_state.attr,