[PATCH 4/5] log: convert pr_*() to logging

[Sean Anderson]

On 1/4/21 2:02 AM, Heinrich Schuchardt wrote:
> In drivers we use a family of printing functions including pr_err() and
> pr_cont(). CONFIG_LOGLEVEL is used to control which of these lead to output
> via printf().
> 
> Our logging functions allow finer grained control of output. So replace
> printf() by the matching logging functions. The usage of CONFIG_LOGLEVEL
> remains unchanged.
> 
> Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
> ---
>   include/linux/bitops.h |  4 ++-
>   include/linux/printk.h | 82 +++++++++++++++++++++++-------------------
>   2 files changed, 48 insertions(+), 38 deletions(-)
> 
> diff --git a/include/linux/bitops.h b/include/linux/bitops.h
> index 16f28993f5..d2e5ca026e 100644
> --- a/include/linux/bitops.h
> +++ b/include/linux/bitops.h
> @@ -6,7 +6,6 @@
>   #include <asm/types.h>
>   #include <asm-generic/bitsperlong.h>
>   #include <linux/compiler.h>
> -#include <linux/kernel.h>
> 
>   #ifdef	__KERNEL__
>   #define BIT(nr)			(1UL << (nr))
> @@ -19,6 +18,9 @@
>   #define BITS_TO_LONGS(nr)	DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
>   #endif
> 
> +/* kernel.h includes log.h which include bitops.h */
> +#include <linux/kernel.h>
> +
>   /*
>    * Create a contiguous bitmask starting at bit position @l and ending at
>    * position @h. For example
> diff --git a/include/linux/printk.h b/include/linux/printk.h
> index 088513ad29..5e85513853 100644
> --- a/include/linux/printk.h
> +++ b/include/linux/printk.h
> @@ -1,6 +1,7 @@
>   #ifndef __KERNEL_PRINTK__
>   #define __KERNEL_PRINTK__
> 
> +#include <log.h>
>   #include <stdio.h>
>   #include <linux/compiler.h>
> 
> @@ -28,49 +29,56 @@
>   	0;						\
>   })
> 
> -#define __printk(level, fmt, ...)					\
> -({									\
> -	level < CONFIG_LOGLEVEL ? printk(fmt, ##__VA_ARGS__) : 0;	\

Couldn't we just do

#define __printk(level, fmt, ...) log(LOG_CATEGORY, level, fmt, ##__VA_ARGS__)

> -})
> -
>   #ifndef pr_fmt
>   #define pr_fmt(fmt) fmt
>   #endif
> 
> -#define pr_emerg(fmt, ...) \
> -	__printk(0, pr_fmt(fmt), ##__VA_ARGS__)
> -#define pr_alert(fmt, ...) \
> -	__printk(1, pr_fmt(fmt), ##__VA_ARGS__)
> -#define pr_crit(fmt, ...) \
> -	__printk(2, pr_fmt(fmt), ##__VA_ARGS__)
> -#define pr_err(fmt, ...) \
> -	__printk(3, pr_fmt(fmt), ##__VA_ARGS__)
> -#define pr_warning(fmt, ...) \
> -	__printk(4, pr_fmt(fmt), ##__VA_ARGS__)
> -#define pr_warn pr_warning
> -#define pr_notice(fmt, ...) \
> -	__printk(5, pr_fmt(fmt), ##__VA_ARGS__)
> -#define pr_info(fmt, ...) \
> -	__printk(6, pr_fmt(fmt), ##__VA_ARGS__)
> -
> -#define pr_cont(fmt, ...) \
> -	printk(fmt, ##__VA_ARGS__)
> -
> -/* pr_devel() should produce zero code unless DEBUG is defined */
> -#ifdef DEBUG
> -#define pr_devel(fmt, ...) \
> -	__printk(7, pr_fmt(fmt), ##__VA_ARGS__)
> -#else
> -#define pr_devel(fmt, ...) \
> -	no_printk(pr_fmt(fmt), ##__VA_ARGS__)
> -#endif
> +#define pr_emerg(fmt, ...)						\
> +({									\
> +	CONFIG_LOGLEVEL > 0 ? log_emerg(fmt, ##__VA_ARGS__) : 0;	\
> +})

There is also an off-by-one mismatch between the numbers here and the
log level constants. E.g. LOGL_INFO is 6, but pr_info only gets emitted
if CONFIG_LOGLEVEL is >= 7.

--Sean

> +#define pr_alert(fmt, ...)						\
> +({									\
> +	CONFIG_LOGLEVEL > 1 ? log_alert(fmt, ##__VA_ARGS__) : 0;	\
> +})
> +#define pr_crit(fmt, ...)						\
> +({									\
> +	CONFIG_LOGLEVEL > 2 ? log_crit(fmt, ##__VA_ARGS__) : 0;		\
> +})
> +#define pr_err(fmt, ...)						\
> +({									\
> +	CONFIG_LOGLEVEL > 3 ? log_err(fmt, ##__VA_ARGS__) : 0;		\
> +})
> +#define pr_warn(fmt, ...)						\
> +({									\
> +	CONFIG_LOGLEVEL > 4 ? log_warning(fmt, ##__VA_ARGS__) : 0;	\
> +})
> +#define pr_notice(fmt, ...)						\
> +({									\
> +	CONFIG_LOGLEVEL > 5 ? log_notice(fmt, ##__VA_ARGS__) : 0;	\
> +})
> +#define pr_info(fmt, ...)						\
> +({									\
> +	CONFIG_LOGLEVEL > 6 ? log_info(fmt, ##__VA_ARGS__) : 0;		\
> +})
> +#define pr_debug(fmt, ...)						\
> +({									\
> +	CONFIG_LOGLEVEL > 7 ? log_debug(fmt, ##__VA_ARGS__) : 0;	\
> +})
> +#define pr_devel(fmt, ...)						\
> +({									\
> +	CONFIG_LOGLEVEL > 7 ? log_debug(fmt, ##__VA_ARGS__) : 0;	\
> +})
> 
> -#ifdef DEBUG
> -#define pr_debug(fmt, ...) \
> -	__printk(7, pr_fmt(fmt), ##__VA_ARGS__)
> +#ifdef CONFIG_LOG
> +#define pr_cont(fmt, ...)						\
> +({									\
> +	gd->logl_prev < CONFIG_LOGLEVEL ?				\
> +		log_cont(fmt, ##__VA_ARGS__) : 0;			\
> +})
>   #else
> -#define pr_debug(fmt, ...) \
> -	no_printk(pr_fmt(fmt), ##__VA_ARGS__)
> +#define pr_cont(fmt, ...)						\
> +	printk(fmt, ##__VA_ARGS__)
>   #endif
> 
>   #define printk_once(fmt, ...) \
> --
> 2.29.2
>