[Skiboot] [PATCH] console: Set log level from nvram

[Cyril Bur]

On Thu, 2017-04-20 at 17:15 +1000, Michael Neuling wrote:
> This adds two new nvram options to set the console log level for the
> driver/uart and in memory.  These are called log-level-memory and
                             ^ Space?


> log-level-driver.
> 
> These are only set once we have nvram inited.
> 
> To set them you do:
>   nvram -p ibm,skiboot --update-config log-level-memory=9
>   nvram -p ibm,skiboot --update-config log-level-driver=9
> 
> You can also use the named versions of emerg, alert, crit, err,
> warning, notice, printf, info, debug, trace or insane.  ie.
>     nvram -p ibm,skiboot --update-config log-level-driver=insane
> 
> Suggested-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> Signed-off-by: Michael Neuling <mikey at neuling.org>

Reviewed-by: Cyril Bur <cyril.bur at au1.ibm.com>

> ---
>  core/init.c       | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  include/skiboot.h |  4 +++-
>  2 files changed, 63 insertions(+), 1 deletion(-)
> 
> diff --git a/core/init.c b/core/init.c
> index 6b8137c8c7..9d4d185dda 100644
> --- a/core/init.c
> +++ b/core/init.c
> @@ -68,6 +68,8 @@ struct debug_descriptor debug_descriptor = {
>  	.state_flags	= 0,
>  	.memcons_phys	= (uint64_t)&memcons,
>  	.trace_mask	= 0, /* All traces disabled by default */
> +	/* console log level:
> +	 *   high 4 bits in memory, low 4 bits driver (e.g. uart). */
>  #ifdef DEBUG
>  	.console_log_levels = (PR_DEBUG << 4) | PR_DEBUG,
>  #else
> @@ -615,6 +617,61 @@ static void dt_init_misc(void)
>  	dt_fixups();
>  }
>  
> +static u8 console_get_level(const char *s)
> +{
> +	if (strcmp(s, "emerg") == 0)
> +		return PR_EMERG;
> +	if (strcmp(s, "alert") == 0)
> +		return PR_ALERT;
> +	if (strcmp(s, "crit") == 0)
> +		return PR_CRIT;
> +	if (strcmp(s, "err") == 0)
> +		return PR_ERR;
> +	if (strcmp(s, "warning") == 0)
> +		return PR_WARNING;
> +	if (strcmp(s, "notice") == 0)
> +		return PR_NOTICE;
> +	if (strcmp(s, "printf") == 0)
> +		return PR_PRINTF;
> +	if (strcmp(s, "info") == 0)
> +		return PR_INFO;
> +	if (strcmp(s, "debug") == 0)
> +		return PR_DEBUG;
> +	if (strcmp(s, "trace") == 0)
> +		return PR_TRACE;
> +	if (strcmp(s, "insane") == 0)
> +		return PR_INSANE;
> +	/* Assume it's a number instead */

So if you'd told me that this patch existed I would have naively put
the actual #define name as a string in the flash but on reflection this
is better.

> +	return atoi(s);

Ability to put number is great++!

> +}
> +
> +static void console_log_level(void)
> +{
> +	const char *s;
> +	u8 level;
> +
> +	/* console log level:
> +	 *   high 4 bits in memory, low 4 bits driver (e.g. uart). */
> +	s = nvram_query("log-level-driver");
> +	if (s) {
> +		level = console_get_level(s);
> +		debug_descriptor.console_log_levels =
> +			(debug_descriptor.console_log_levels & 0xf0 ) |
> +			(level & 0x0f);
> +		prlog(PR_NOTICE, "console: Setting driver log level to %i\n",
> +		      level & 0x0f);
> +	}
> +	s = nvram_query("log-level-memory");
> +	if (s) {
> +		level = console_get_level(s);
> +		debug_descriptor.console_log_levels =
> +			(debug_descriptor.console_log_levels & 0x0f ) |
> +			((level & 0x0f) << 4);
> +		prlog(PR_NOTICE, "console: Setting memory log level to %i\n",
> +		      level & 0x0f);
> +	}
> +}
> +
>  typedef void (*ctorcall_t)(void);
>  
>  static void __nomcount do_ctors(void)
> @@ -921,6 +978,9 @@ void __noreturn __nomcount main_cpu_entry(const void *fdt)
>  	/* Read in NVRAM and set it up */
>  	nvram_init();
>  
> +	/* Set the console level */
> +	console_log_level();
> +
>  	/* Secure/Trusted Boot init. We look for /ibm,secureboot in DT */
>  	stb_init();
>  
> diff --git a/include/skiboot.h b/include/skiboot.h
> index 2b1f8a577e..5c8b0c854d 100644
> --- a/include/skiboot.h
> +++ b/include/skiboot.h
> @@ -91,7 +91,9 @@ static inline bool opal_booting(void)
>  	return !(debug_descriptor.state_flags & OPAL_BOOT_COMPLETE);
>  }
>  
> -/* Console logging */
> +/* Console logging
> + * Update console_get_level() if you add here
> + */
>  #define PR_EMERG	0
>  #define PR_ALERT	1
>  #define PR_CRIT		2