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From: John Ogness <john.ogness@linutronix.de>
Date: Tue, 26 Sep 2023 14:43:30 +0000
Subject: [PATCH 123/134] printk: nbcon: Add context to console_is_usable()
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.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
@@ -100,7 +100,7 @@ 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;
@@ -109,10 +109,13 @@ static inline bool console_is_usable(str
return false;
if (flags & CON_NBCON) {
- if (!con->write_atomic)
- return false;
- if (!con->write_thread || !con->kthread)
- return false;
+ if (use_atomic) {
+ if (!con->write_atomic)
+ return false;
+ } else {
+ if (!con->write_thread || !con->kthread)
+ return false;
+ }
} else {
if (!con->write)
return false;
@@ -178,7 +181,8 @@ static inline void nbcon_atomic_flush_al
static inline bool nbcon_atomic_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
@@ -963,7 +963,7 @@ static bool nbcon_kthread_should_wakeup(
cookie = console_srcu_read_lock();
flags = console_srcu_read_flags(con);
- is_usable = console_is_usable(con, flags);
+ is_usable = console_is_usable(con, flags, false);
console_srcu_read_unlock(cookie);
if (!is_usable)
@@ -1022,7 +1022,7 @@ 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->driver_enter(con, &flags);
/*
@@ -1203,7 +1203,7 @@ static void __nbcon_atomic_flush_all(u64
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
@@ -3040,7 +3040,7 @@ 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;
@@ -3945,8 +3945,10 @@ 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);
|
