Remove orphaned CONFIG_PRINTK_SAFE_LOG_BUF_SHIFT

After the commit 93d102f0 ("printk: remove safe buffers"),
CONFIG_PRINTK_SAFE_LOG_BUF_SHIFT is no longer useful.  Remove it.
Signed-off-by: Marc Aurèle La France <tsi@tuyoix.net>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
[pmladek@suse.cz: Cleaned up the commit message.]
Signed-off-by: Petr Mladek <pmladek@suse.com>
Fixes: 93d102f0 ("printk: remove safe buffers")
Link: https://lore.kernel.org/r/5c19e248-1b6b-330c-7c4c-a824688daefe@tuyoix.net

arch/powerpc/configs/microwatt_defconfig

@@ -4,7 +4,6 @@ CONFIG_HIGH_RES_TIMERS=y
 CONFIG_PREEMPT_VOLUNTARY=y
 CONFIG_TICK_CPU_ACCOUNTING=y
 CONFIG_LOG_BUF_SHIFT=16
-CONFIG_PRINTK_SAFE_LOG_BUF_SHIFT=12
 CONFIG_CGROUPS=y
 CONFIG_BLK_DEV_INITRD=y
 CONFIG_CC_OPTIMIZE_FOR_SIZE=y

arch/riscv/configs/nommu_k210_defconfig

 # CONFIG_CPU_ISOLATION is not set
 CONFIG_LOG_BUF_SHIFT=13
-CONFIG_PRINTK_SAFE_LOG_BUF_SHIFT=12
 CONFIG_BLK_DEV_INITRD=y
 # CONFIG_RD_GZIP is not set
 # CONFIG_RD_BZIP2 is not set

arch/riscv/configs/nommu_k210_sdcard_defconfig

 # CONFIG_CPU_ISOLATION is not set
 CONFIG_LOG_BUF_SHIFT=13
-CONFIG_PRINTK_SAFE_LOG_BUF_SHIFT=12
 CONFIG_CC_OPTIMIZE_FOR_SIZE=y
 # CONFIG_SYSFS_SYSCALL is not set
 # CONFIG_FHANDLE is not set

arch/riscv/configs/nommu_virt_defconfig

 # CONFIG_CPU_ISOLATION is not set
 CONFIG_LOG_BUF_SHIFT=16
-CONFIG_PRINTK_SAFE_LOG_BUF_SHIFT=12
 CONFIG_BLK_DEV_INITRD=y
 # CONFIG_RD_BZIP2 is not set
 # CONFIG_RD_LZMA is not set

init/Kconfig

@@ -769,30 +769,6 @@ config LOG_CPU_MAX_BUF_SHIFT
 		     13 =>   8 KB for each CPU
 		     12 =>   4 KB for each CPU
 
-config PRINTK_SAFE_LOG_BUF_SHIFT
-	int "Temporary per-CPU printk log buffer size (12 => 4KB, 13 => 8KB)"
-	range 10 21
-	default 13
-	depends on PRINTK
-	help
-	  Select the size of an alternate printk per-CPU buffer where messages
-	  printed from unsafe contexts are temporary stored. One example would
-	  be NMI messages, another one - printk recursion. The messages are
-	  copied to the main log buffer in a safe context to avoid a deadlock.
-	  The value defines the size as a power of 2.
-
-	  Those messages are rare and limited. The largest one is when
-	  a backtrace is printed. It usually fits into 4KB. Select
-	  8KB if you want to be on the safe side.
-
-	  Examples:
-		     17 => 128 KB for each CPU
-		     16 =>  64 KB for each CPU
-		     15 =>  32 KB for each CPU
-		     14 =>  16 KB for each CPU
-		     13 =>   8 KB for each CPU
-		     12 =>   4 KB for each CPU
-
 config PRINTK_INDEX
 	bool "Printk indexing debugfs interface"
 	depends on PRINTK && DEBUG_FS