diff --git a/Documentation/ABI/testing/sysfs-class-remoteproc b/Documentation/ABI/testing/sysfs-class-remoteproc index 36094fbeb974..050bd25aaa15 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 , Ohad Ben-Cohen +Description: Remote processor coredump configuration + + Reports the coredump configuration of the remote processor, + which will be one of: + + "disabled" + "enabled" + "inline" + + "disabled" means no dump will be collected. + + "enabled" 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. diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c index eea514cec50e..85002715c3ea 100644 --- a/drivers/remoteproc/remoteproc_sysfs.c +++ b/drivers/remoteproc/remoteproc_sysfs.c @@ -10,6 +10,68 @@ #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_DISABLED] = "disabled", + [RPROC_COREDUMP_ENABLED] = "enabled", + [RPROC_COREDUMP_INLINE] = "inline", +}; + +/* 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: + * + * disabled: This is the default coredump mechanism. Recovery will proceed + * without collecting any dump. + * + * default: 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. + */ +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, "disabled")) { + rproc->dump_conf = RPROC_COREDUMP_DISABLED; + } else if (sysfs_streq(buf, "enabled")) { + rproc->dump_conf = RPROC_COREDUMP_ENABLED; + } else if (sysfs_streq(buf, "inline")) { + rproc->dump_conf = RPROC_COREDUMP_INLINE; + } 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 +200,7 @@ 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,