1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
|
From: John Ogness <john.ogness@linutronix.de>
Date: Tue, 26 Sep 2023 14:43:30 +0000
Subject: [PATCH 35/48] printk: nbcon: Add context to console_is_usable()
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.8/older/patches-6.8.2-rt11.tar.xz
The nbcon consoles have two callbacks to be used for different
contexts. In order to determine if an nbcon console is usable,
console_is_usable() needs to know if it is a context that will
use the write_atomic() callback or the write_thread() callback.
Add an extra parameter @use_atomic to specify this.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
kernel/printk/internal.h | 16 ++++++++++------
kernel/printk/nbcon.c | 6 +++---
kernel/printk/printk.c | 6 ++++--
3 files changed, 17 insertions(+), 11 deletions(-)
--- a/kernel/printk/internal.h
+++ b/kernel/printk/internal.h
@@ -98,7 +98,7 @@ void nbcon_kthread_create(struct console
* which can also play a role in deciding if @con can be used to print
* records.
*/
-static inline bool console_is_usable(struct console *con, short flags)
+static inline bool console_is_usable(struct console *con, short flags, bool use_atomic)
{
if (!(flags & CON_ENABLED))
return false;
@@ -107,10 +107,13 @@ static inline bool console_is_usable(str
return false;
if (flags & CON_NBCON) {
- if (!con->write_atomic)
- return false;
- if (!con->write_thread)
- return false;
+ if (use_atomic) {
+ if (!con->write_atomic)
+ return false;
+ } else {
+ if (!con->write_thread)
+ return false;
+ }
} else {
if (!con->write)
return false;
@@ -175,7 +178,8 @@ static inline void nbcon_atomic_flush_pe
static inline bool nbcon_legacy_emit_next_record(struct console *con, bool *handover,
int cookie) { return false; }
-static inline bool console_is_usable(struct console *con, short flags) { return false; }
+static inline bool console_is_usable(struct console *con, short flags,
+ bool use_atomic) { return false; }
#endif /* CONFIG_PRINTK */
--- a/kernel/printk/nbcon.c
+++ b/kernel/printk/nbcon.c
@@ -968,7 +968,7 @@ static bool nbcon_kthread_should_wakeup(
cookie = console_srcu_read_lock();
flags = console_srcu_read_flags(con);
- if (console_is_usable(con, flags)) {
+ if (console_is_usable(con, flags, false)) {
/* Bring the sequence in @ctxt up to date */
ctxt->seq = nbcon_seq_read(con);
@@ -1026,7 +1026,7 @@ static int nbcon_kthread_func(void *__co
con_flags = console_srcu_read_flags(con);
- if (console_is_usable(con, con_flags)) {
+ if (console_is_usable(con, con_flags, false)) {
con->device_lock(con, &flags);
/*
@@ -1246,7 +1246,7 @@ static void __nbcon_atomic_flush_pending
if (!(flags & CON_NBCON))
continue;
- if (!console_is_usable(con, flags))
+ if (!console_is_usable(con, flags, true))
continue;
if (nbcon_seq_read(con) >= stop_seq)
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -3056,7 +3056,7 @@ static bool console_flush_all(bool do_co
if ((flags & CON_NBCON) && con->kthread)
continue;
- if (!console_is_usable(con, flags))
+ if (!console_is_usable(con, flags, true))
continue;
any_usable = true;
@@ -3991,8 +3991,10 @@ static bool __pr_flush(struct console *c
* that they make forward progress, so only increment
* @diff for usable consoles.
*/
- if (!console_is_usable(c, flags))
+ if (!console_is_usable(c, flags, true) &&
+ !console_is_usable(c, flags, false)) {
continue;
+ }
if (flags & CON_NBCON) {
printk_seq = nbcon_seq_read(c);
|
