[PATCH printk v3 02/15] printk: cpu sync always disable interrupts

John Ogness
2022-04-19T23:46:44Z

The CPU sync functions are a NOP for !CONFIG_SMP. But for
!CONFIG_SMP they still need to disable interrupts in order to
preserve context within the CPU sync sections.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
---
include/linux/printk.h | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/linux/printk.h b/include/linux/printk.h
index 859323a52985..b70a42f94031 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -281,9 +281,16 @@ extern int __printk_cpu_sync_try_get(void);
extern void __printk_cpu_sync_wait(void);
extern void __printk_cpu_sync_put(void);

+#else
+
+#define __printk_cpu_sync_try_get() true
+#define __printk_cpu_sync_wait()
+#define __printk_cpu_sync_put()
+#endif /* CONFIG_SMP */
+
/**
- * printk_cpu_sync_get_irqsave() - Acquire the printk cpu-reentrant spinning
- * lock and disable interrupts.
+ * printk_cpu_sync_get_irqsave() - Disable interrupts and acquire the printk
+ * cpu-reentrant spinning lock.
* @flags: Stack-allocated storage for saving local interrupt state,
* to be passed to printk_cpu_sync_put_irqrestore().
*
@@ -322,13 +329,6 @@ extern void __printk_cpu_sync_put(void);
local_irq_restore(flags); \
} while (0)

-#else
-
-#define printk_cpu_sync_get_irqsave(flags) ((void)flags)
-#define printk_cpu_sync_put_irqrestore(flags) ((void)flags)
-
-#endif /* CONFIG_SMP */
-
extern int kptr_restrict;

/**
--
2.30.2