From: Rishabh Bhatnagar <rishabhb@codeaurora.org>
To: linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org,
bjorn.andersson@linaro.org
Cc: tsoni@codeaurora.org, psodagud@codeaurora.org,
sidgup@codeaurora.org,
Rishabh Bhatnagar <rishabhb@codeaurora.org>
Subject: [PATCH v7 3/3] remoteproc: Add recovery configuration to the sysfs interface
Date: Fri, 2 Oct 2020 11:09:04 -0700 [thread overview]
Message-ID: <1601662144-5964-4-git-send-email-rishabhb@codeaurora.org> (raw)
In-Reply-To: <1601662144-5964-1-git-send-email-rishabhb@codeaurora.org>
Add recovery configuration to the sysfs interface. This will
allow usage of this configuration feature in production
devices where access to debugfs might be limited.
Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
---
Documentation/ABI/testing/sysfs-class-remoteproc | 20 +++++++++
drivers/remoteproc/remoteproc_sysfs.c | 56 ++++++++++++++++++++++++
2 files changed, 76 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-class-remoteproc b/Documentation/ABI/testing/sysfs-class-remoteproc
index 050bd25..066b9b6 100644
--- a/Documentation/ABI/testing/sysfs-class-remoteproc
+++ b/Documentation/ABI/testing/sysfs-class-remoteproc
@@ -82,3 +82,23 @@ Description: Remote processor coredump configuration
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.
+
+What: /sys/class/remoteproc/.../recovery
+Date: July 2020
+Contact: Bjorn Andersson <bjorn.andersson@linaro.org>, Ohad Ben-Cohen <ohad@wizery.com>
+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.
diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c
index 8500271..d1cf7bf 100644
--- a/drivers/remoteproc/remoteproc_sysfs.c
+++ b/drivers/remoteproc/remoteproc_sysfs.c
@@ -10,6 +10,61 @@
#define to_rproc(d) container_of(d, struct rproc, dev)
+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 +256,7 @@ static DEVICE_ATTR_RO(name);
static struct attribute *rproc_attrs[] = {
&dev_attr_coredump.attr,
+ &dev_attr_recovery.attr,
&dev_attr_firmware.attr,
&dev_attr_state.attr,
&dev_attr_name.attr,
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
prev parent reply other threads:[~2020-10-02 18:09 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-02 18:09 [PATCH v7 0/3] Move recovery/coredump configuration to sysfs Rishabh Bhatnagar
2020-10-02 18:09 ` [PATCH v7 1/3] remoteproc: Change default dump configuration to "disabled" Rishabh Bhatnagar
2020-10-02 18:09 ` [PATCH v7 2/3] remoteproc: Add coredump as part of sysfs interface Rishabh Bhatnagar
2020-10-02 18:09 ` Rishabh Bhatnagar [this message]
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