LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Rishabh Bhatnagar <rishabhb@codeaurora.org>
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 <rishabhb@codeaurora.org>
Subject: [PATCH v7 4/4] remoteproc: Add coredump debugfs entry
Date: Thu,  9 Jul 2020 13:31:56 -0700
Message-ID: <1594326716-15474-5-git-send-email-rishabhb@codeaurora.org> (raw)
In-Reply-To: <1594326716-15474-1-git-send-email-rishabhb@codeaurora.org>

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>
---
 drivers/remoteproc/remoteproc_debugfs.c | 90 +++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)

diff --git a/drivers/remoteproc/remoteproc_debugfs.c b/drivers/remoteproc/remoteproc_debugfs.c
index 732770e..16a4196 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)
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


      parent reply index

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-09 20:31 [PATCH v7 0/4] Extend coredump functionality Rishabh Bhatnagar
2020-07-09 20:31 ` [PATCH v7 1/4] remoteproc: Move coredump functionality to a new file Rishabh Bhatnagar
2020-07-09 20:31 ` [PATCH v1 2/4] remoteproc: qcom_q6v5_mss: Replace mask based tracking with size Rishabh Bhatnagar
2020-07-14 17:18   ` Mathieu Poirier
2020-07-14 18:12     ` Sibi Sankar
2020-07-16  8:10     ` Sibi Sankar
2020-07-16 18:24       ` rishabhb
2020-07-20 16:57   ` Mathieu Poirier
2020-07-09 20:31 ` [PATCH v7 3/4] remoteproc: Add inline coredump functionality Rishabh Bhatnagar
2020-07-14 17:53   ` Mathieu Poirier
2020-07-15 19:22     ` rishabhb
2020-07-15 21:55       ` Mathieu Poirier
2020-07-16  8:25   ` Sibi Sankar
2020-07-16 18:25     ` rishabhb
2020-07-09 20:31 ` Rishabh Bhatnagar [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1594326716-15474-5-git-send-email-rishabhb@codeaurora.org \
    --to=rishabhb@codeaurora.org \
    --cc=bjorn.andersson@linaro.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-remoteproc@vger.kernel.org \
    --cc=mathieu.poirier@linaro.org \
    --cc=psodagud@codeaurora.org \
    --cc=sidgup@codeaurora.org \
    --cc=tsoni@codeaurora.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git
	git clone --mirror https://lore.kernel.org/lkml/8 lkml/git/8.git
	git clone --mirror https://lore.kernel.org/lkml/9 lkml/git/9.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git