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From: John Ogness <john.ogness@linutronix.de>
To: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-kernel@vger.kernel.org,
	linux-fsdevel@vger.kernel.org
Subject: [PATCH printk v2 14/18] proc: Add nbcon support for /proc/consoles
Date: Tue,  4 Jun 2024 01:30:49 +0206
Message-Id: <20240603232453.33992-15-john.ogness@linutronix.de>
In-Reply-To: <20240603232453.33992-1-john.ogness@linutronix.de>
References: <20240603232453.33992-1-john.ogness@linutronix.de>
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Update /proc/consoles output to show 'W' if an nbcon write
callback is implemented (write_atomic or write_thread).

Also update /proc/consoles output to show 'N' if it is an
nbcon console.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
---
 fs/proc/consoles.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/fs/proc/consoles.c b/fs/proc/consoles.c
index 7036fdfa0bec..c3c01ec2273c 100644
--- a/fs/proc/consoles.c
+++ b/fs/proc/consoles.c
@@ -21,12 +21,14 @@ static int show_console_dev(struct seq_file *m, void *v)
 		{ CON_ENABLED,		'E' },
 		{ CON_CONSDEV,		'C' },
 		{ CON_BOOT,		'B' },
+		{ CON_NBCON,		'N' },
 		{ CON_PRINTBUFFER,	'p' },
 		{ CON_BRL,		'b' },
 		{ CON_ANYTIME,		'a' },
 	};
 	char flags[ARRAY_SIZE(con_flags) + 1];
 	struct console *con = v;
+	char con_write = '-';
 	unsigned int a;
 	dev_t dev = 0;
 
@@ -57,9 +59,15 @@ static int show_console_dev(struct seq_file *m, void *v)
 	seq_setwidth(m, 21 - 1);
 	seq_printf(m, "%s%d", con->name, con->index);
 	seq_pad(m, ' ');
-	seq_printf(m, "%c%c%c (%s)", con->read ? 'R' : '-',
-			con->write ? 'W' : '-', con->unblank ? 'U' : '-',
-			flags);
+	if (con->flags & CON_NBCON) {
+		if (con->write_atomic || con->write_thread)
+			con_write = 'W';
+	} else {
+		if (con->write)
+			con_write = 'W';
+	}
+	seq_printf(m, "%c%c%c (%s)", con->read ? 'R' : '-', con_write,
+		   con->unblank ? 'U' : '-', flags);
 	if (dev)
 		seq_printf(m, " %4d:%d", MAJOR(dev), MINOR(dev));
 
-- 
2.39.2