panic/printk: replace this_cpu_in_panic() with panic_on_this_cpu()

The helper this_cpu_in_panic() duplicated logic already provided by
panic_on_this_cpu().

Remove this_cpu_in_panic() and switch all users to panic_on_this_cpu().

This simplifies the code and avoids having two helpers for the same check.

Link: https://lkml.kernel.org/r/20250825022947.1596226-8-wangjinchao600@gmail.com
Signed-off-by: Jinchao Wang <wangjinchao600@gmail.com>
Cc: Anna Schumaker <anna.schumaker@oracle.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Doug Anderson <dianders@chromium.org>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com>
Cc: Joel Granados <joel.granados@kernel.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Kees Cook <kees@kernel.org>
Cc: Li Huafei <lihuafei1@huawei.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Luo Gengkun <luogengkun@huaweicloud.com>
Cc: Max Kellermann <max.kellermann@ionos.com>
Cc: Nam Cao <namcao@linutronix.de>
Cc: oushixiong <oushixiong@kylinos.cn>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Qianqiang Liu <qianqiang.liu@163.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Sohil Mehta <sohil.mehta@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Thorsten Blum <thorsten.blum@linux.dev>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Cc: Yunhui Cui <cuiyunhui@bytedance.com>
Cc: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/printk.h

@@ -330,8 +330,6 @@ static inline bool pr_flush(int timeout_ms, bool reset_on_progress)
 
 #endif
 
-bool this_cpu_in_panic(void);
-
 #ifdef CONFIG_SMP
 extern int __printk_cpu_sync_try_get(void);
 extern void __printk_cpu_sync_wait(void);

kernel/panic.c

@@ -348,7 +348,7 @@ EXPORT_SYMBOL(panic_on_this_cpu);
  */
 bool panic_on_other_cpu(void)
 {
-	return (panic_in_progress() && !this_cpu_in_panic());
+	return (panic_in_progress() && !panic_on_this_cpu());
 }
 EXPORT_SYMBOL(panic_on_other_cpu);
 

kernel/printk/nbcon.c

@@ -1394,7 +1394,7 @@ enum nbcon_prio nbcon_get_default_prio(void)
 {
 	unsigned int *cpu_emergency_nesting;
 
-	if (this_cpu_in_panic())
+	if (panic_on_this_cpu())
 		return NBCON_PRIO_PANIC;
 
 	cpu_emergency_nesting = nbcon_get_cpu_emergency_nesting();

kernel/printk/printk.c

@@ -17,6 +17,7 @@
  *	01Mar01 Andrew Morton
  */
 
+#include "linux/panic.h"
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kernel.h>
@@ -345,18 +346,6 @@ static void __up_console_sem(unsigned long ip)
 }
 #define up_console_sem() __up_console_sem(_RET_IP_)
 
-/* Return true if a panic is in progress on the current CPU. */
-bool this_cpu_in_panic(void)
-{
-	/*
-	 * We can use raw_smp_processor_id() here because it is impossible for
-	 * the task to be migrated to the panic_cpu, or away from it. If
-	 * panic_cpu has already been set, and we're not currently executing on
-	 * that CPU, then we never will be.
-	 */
-	return unlikely(atomic_read(&panic_cpu) == raw_smp_processor_id());
-}
-
 /*
  * Return true if a panic is in progress on a remote CPU.
  *
@@ -365,7 +354,7 @@ bool this_cpu_in_panic(void)
  */
 bool other_cpu_in_panic(void)
 {
-	return (panic_in_progress() && !this_cpu_in_panic());
+	return (panic_in_progress() && !panic_on_this_cpu());
 }
 
 /*

kernel/printk/printk_ringbuffer.c

@@ -2143,7 +2143,7 @@ static bool _prb_read_valid(struct printk_ringbuffer *rb, u64 *seq,
 			 * But it would have the sequence number returned
 			 * by "prb_next_reserve_seq() - 1".
 			 */
-			if (this_cpu_in_panic() &&
+			if (panic_on_this_cpu() &&
 			    (!debug_non_panic_cpus || legacy_allow_panic_sync) &&
 			    ((*seq + 1) < prb_next_reserve_seq(rb))) {
 				(*seq)++;

lib/dump_stack.c

@@ -102,7 +102,7 @@ static void __dump_stack(const char *log_lvl)
  */
 asmlinkage __visible void dump_stack_lvl(const char *log_lvl)
 {
-	bool in_panic = this_cpu_in_panic();
+	bool in_panic = panic_on_this_cpu();
 	unsigned long flags;
 
 	/*