Commit d20d8e51 authored by Vasily Gorbik's avatar Vasily Gorbik Committed by Alexander Gordeev
Browse files

s390/boot: Add bootdebug option to control debug messages 



Suppress decompressor debug messages by default, similar to regular
kernel debug messages that require 'DEBUG' or 'dyndbg' to be enabled
(depending on CONFIG_DYNAMIC_DEBUG). Introduce a 'bootdebug' option to
enable printing these messages when needed.

All messages are still stored in the boot ring buffer regardless.

To enable boot debug messages:

  bootdebug debug

Or combine with 'earlyprintk' to print them without delay:

  bootdebug debug earlyprintk

Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Acked-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
parent c09f8d0a

arch/s390/boot/ipl_parm.c

+2 −0
Original line number Diff line number Diff line
@@ -317,6 +317,8 @@ void parse_boot_command_line(void) 
			boot_earlyprintk = true;

		if (!strcmp(param, "debug"))

			boot_console_loglevel = CONSOLE_LOGLEVEL_DEBUG;

		if (!strcmp(param, "bootdebug"))

			bootdebug = true;

		if (!strcmp(param, "quiet"))

			boot_console_loglevel = CONSOLE_LOGLEVEL_QUIET;

		if (!strcmp(param, "ignore_loglevel"))

arch/s390/boot/printk.c

+4 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ bool boot_ignore_loglevel; 
char __bootdata(boot_rb)[PAGE_SIZE * 2];

bool __bootdata(boot_earlyprintk);

size_t __bootdata(boot_rb_off);

bool __bootdata(bootdebug);



static void boot_rb_add(const char *str, size_t len)

{
@@ -168,6 +169,9 @@ static void boot_console_earlyprintk(const char *buf) 
	/* always print emergency messages */

	if (level > LOGLEVEL_EMERG && !boot_earlyprintk)

		return;

	/* print debug messages only when bootdebug is enabled */

	if (level == LOGLEVEL_DEBUG && !bootdebug)

		return;

	if (boot_ignore_loglevel || level < boot_console_loglevel)

		sclp_early_printk(printk_skip_level(buf));

}

arch/s390/include/asm/boot_data.h

+1 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ extern unsigned long early_ipl_comp_list_size; 
extern char boot_rb[PAGE_SIZE * 2];

extern bool boot_earlyprintk;

extern size_t boot_rb_off;

extern bool bootdebug;



#define boot_rb_foreach(cb)							\

	do {									\

arch/s390/kernel/early.c

+1 −0
Original line number Diff line number Diff line
@@ -50,6 +50,7 @@ decompressor_handled_param(facilities); 
decompressor_handled_param(nokaslr);

decompressor_handled_param(cmma);

decompressor_handled_param(relocate_lowcore);

decompressor_handled_param(bootdebug);

#if IS_ENABLED(CONFIG_KVM)

decompressor_handled_param(prot_virt);

#endif

arch/s390/kernel/setup.c

+8 −2
Original line number Diff line number Diff line
@@ -160,6 +160,7 @@ struct oldmem_data __bootdata_preserved(oldmem_data); 
char __bootdata(boot_rb)[PAGE_SIZE * 2];

bool __bootdata(boot_earlyprintk);

size_t __bootdata(boot_rb_off);

bool __bootdata(bootdebug);



unsigned long __bootdata_preserved(VMALLOC_START);

EXPORT_SYMBOL(VMALLOC_START);
@@ -882,13 +883,18 @@ static void __init log_component_list(void) 
}



/*

 * Print avoiding interpretation of % in buf

 * Print avoiding interpretation of % in buf and taking bootdebug option

 * into consideration.

 */

static void __init print_rb_entry(char *buf)

{

	char fmt[] = KERN_SOH "0boot: %s";

	int level = printk_get_level(buf);



	fmt[1] = printk_get_level(buf);

	if (level == KERN_DEBUG[1] && !bootdebug)

		return;



	fmt[1] = level;

	printk(fmt, printk_skip_level(buf));

}