printk/nbcon: use panic_on_this_cpu() helper

nbcon_context_try_acquire() compared panic_cpu directly with
smp_processor_id().  This open-coded check is now provided by
panic_on_this_cpu().

Switch to panic_on_this_cpu() to simplify the code and improve readability.

Link: https://lkml.kernel.org/r/20250825022947.1596226-7-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>

diff --git a/kernel/printk/nbcon.c b/kernel/printk/nbcon.c
index 646801813415f0abe40cabf2f28ca9e30664f028..7490865e2f44a357fc44ed9538f24ebea01d79a3 100644 (file)
--- a/kernel/printk/nbcon.c
+++ b/kernel/printk/nbcon.c
@@ -2,6 +2,7 @@
 // Copyright (C) 2022 Linutronix GmbH, John Ogness
 // Copyright (C) 2022 Intel, Thomas Gleixner
 
+#include "linux/panic.h"
 #include <linux/atomic.h>
 #include <linux/bug.h>
 #include <linux/console.h>
@@ -589,7 +590,6 @@ static struct printk_buffers panic_nbcon_pbufs;
  */
 static bool nbcon_context_try_acquire(struct nbcon_context *ctxt, bool is_reacquire)
 {
-       unsigned int cpu = smp_processor_id();
        struct console *con = ctxt->console;
        struct nbcon_state cur;
        int err;
@@ -614,7 +614,7 @@ out:
        /* Acquire succeeded. */
 
        /* Assign the appropriate buffer for this context. */
-       if (atomic_read(&panic_cpu) == cpu)
+       if (panic_on_this_cpu())
                ctxt->pbufs = &panic_nbcon_pbufs;
        else
                ctxt->pbufs = con->pbufs;