[PATCH printk v2 14/18] proc: Add nbcon support for /proc/consoles

[John Ogness <john.ogness@xxxxxxxxxxxxx>]

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@xxxxxxxxxxxxx>
---
 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