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authorRishabh Bhatnagar <rishabhb@codeaurora.org>2020-07-17 01:20:35 +0300
committerBjorn Andersson <bjorn.andersson@linaro.org>2020-07-22 00:04:12 +0300
commit3afdc59e4390487f04f2435b7e8a6289984e0a1e (patch)
treed10b37517fd3bf531c915442598cb5b331af0473
parentc97319881c9116dc7c56dd30115567b4078c4ba6 (diff)
downloadlinux-3afdc59e4390487f04f2435b7e8a6289984e0a1e.tar.xz
remoteproc: Add coredump debugfs entry
Add coredump debugfs entry to configure the type of dump that will be collected during recovery. User can select between default or inline coredump functionality. Also coredump collection can be disabled through this interface. This functionality can be configured differently for different remote processors. Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Tested-by: Sibi Sankar <sibis@codeaurora.org> Reviewed-by: Sibi Sankar <sibis@codeaurora.org> Link: https://lore.kernel.org/r/1594938035-7327-6-git-send-email-rishabhb@codeaurora.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
-rw-r--r--drivers/remoteproc/remoteproc_debugfs.c90
1 files changed, 90 insertions, 0 deletions
diff --git a/drivers/remoteproc/remoteproc_debugfs.c b/drivers/remoteproc/remoteproc_debugfs.c
index 732770e92b99..2e3b3e22e1d0 100644
--- a/drivers/remoteproc/remoteproc_debugfs.c
+++ b/drivers/remoteproc/remoteproc_debugfs.c
@@ -28,6 +28,94 @@
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.
@@ -337,6 +425,8 @@ 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)