Expose coredump configuration in sysfs under a feature flag. This is useful for systems where access to debugfs might be limited.
Signed-off-by: Rishabh Bhatnagar <[email protected]> --- Documentation/ABI/testing/sysfs-class-remoteproc | 24 +++++++++ drivers/remoteproc/remoteproc_debugfs.c | 4 ++ drivers/remoteproc/remoteproc_sysfs.c | 68 ++++++++++++++++++++++++ 3 files changed, 96 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-class-remoteproc b/Documentation/ABI/testing/sysfs-class-remoteproc index 36094fb..f6c44fa 100644 --- a/Documentation/ABI/testing/sysfs-class-remoteproc +++ b/Documentation/ABI/testing/sysfs-class-remoteproc @@ -58,3 +58,27 @@ 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: Bjorn Andersson <[email protected]>, Ohad Ben-Cohen <[email protected]> +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. diff --git a/drivers/remoteproc/remoteproc_debugfs.c b/drivers/remoteproc/remoteproc_debugfs.c index 2e3b3e2..48dfd0a 100644 --- a/drivers/remoteproc/remoteproc_debugfs.c +++ b/drivers/remoteproc/remoteproc_debugfs.c @@ -27,6 +27,7 @@ /* remoteproc debugfs parent dir */ static struct dentry *rproc_dbg; +#if (!IS_ENABLED(CONFIG_RPROC_SYSFS_CONFIGURATION_SUPPORT)) /* * A coredump-configuration-to-string lookup table, for exposing a * human readable configuration via debugfs. Always keep in sync with @@ -114,6 +115,7 @@ static const struct file_operations rproc_coredump_fops = { .open = simple_open, .llseek = generic_file_llseek, }; +#endif /* * Some remote processors may support dumping trace logs into a shared @@ -425,8 +427,10 @@ 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); +#if (!IS_ENABLED(CONFIG_RPROC_SYSFS_CONFIGURATION_SUPPORT)) debugfs_create_file("coredump", 0600, rproc->dbg_dir, rproc, &rproc_coredump_fops); +#endif } void __init rproc_init_debugfs(void) diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c index eea514c..89b301a 100644 --- a/drivers/remoteproc/remoteproc_sysfs.c +++ b/drivers/remoteproc/remoteproc_sysfs.c @@ -10,6 +10,71 @@ #define to_rproc(d) container_of(d, struct rproc, dev) +#if IS_ENABLED(CONFIG_RPROC_SYSFS_CONFIGURATION_SUPPORT) +/* + * 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); +#endif + /* Expose the loaded / running firmware name via sysfs */ static ssize_t firmware_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -138,6 +203,9 @@ static ssize_t name_show(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR_RO(name); static struct attribute *rproc_attrs[] = { +#if IS_ENABLED(CONFIG_RPROC_SYSFS_CONFIGURATION_SUPPORT) + &dev_attr_coredump.attr, +#endif &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
