printk: collect printk stuff into <linux/printk.h> with loglevel support

When we import code from Linux, with regular re-sync planned, we want
to use printk() and pr_*().  U-Boot does not support them in a clean
way.  So, people end up with local macros, or compat headers here and
there, then we occasionally see build errors of definition conflicts.

We have include/linux/compat.h, but putting all sorts of unrelated
things into a single header is just a temporal workaround.  Hence this
patch, to find the best home for all printk variants.  If you want to
use printk() and friends, please include <linux/printk.h>.  This header
is self-contained, and pulls in only a few headers.

When I was testing this clean-up, I noticed the image size exceeded
its platform limit on some boards.  This is because all pr_*() that
were previously defined as no-op in include/linux/mtd/mtd.h (unless
CONFIG_MTD_DEBUG is set), are now enabled.

To make such boards happy, this commit also implements CONFIG_LOGLEVEL.
The concept is similar to the kernel parameter "loglevel".  (Actually,
the Kconfig help message was taken from kernel-paremeter.txt of Linux)
Messages with a loglevel smaller than console loglevel will be printed.

The difference is the loglevel is build-time determined.  To save the
image size, lower priority pr_*() are compiled out.  I set the default
of CONFIG_LOGLEVEL to 6, i.e. pr_notice and higher priority messages
are compiled in.

I adjusted CONFIG_LOGLEVEL to avoid build error for some boards.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
[trini: Add in SPL_LOGLEVEL that is the same as LOGLEVEL]
Signed-off-by: Tom Rini <trini@konsulko.com>

configs/axm_defconfig

@@ -41,3 +41,4 @@ CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_STMICRO=y
 CONFIG_PHYLIB=y
 CONFIG_USE_TINY_PRINTF=y
+CONFIG_LOGLEVEL=4

configs/colibri_vf_defconfig

@@ -6,6 +6,7 @@ CONFIG_TARGET_COLIBRI_VF=y
 CONFIG_DEFAULT_DEVICE_TREE="vf610-colibri"
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=board/toradex/colibri_vf/imximage.cfg,IMX_NAND"
 CONFIG_BOOTDELAY=1
+CONFIG_LOGLEVEL=3
 CONFIG_VERSION_VARIABLE=y
 # CONFIG_DISPLAY_BOARDINFO is not set
 CONFIG_ARCH_MISC_INIT=y

configs/corvus_defconfig

@@ -14,6 +14,7 @@ CONFIG_SYS_EXTRA_OPTIONS="AT91SAM9M10G45,MACH_TYPE=2066,SYS_USE_NANDFLASH"
 CONFIG_BOOTDELAY=3
 CONFIG_USE_BOOTARGS=y
 CONFIG_BOOTARGS="console=ttyS0,115200 earlyprintk mtdparts=atmel_nand:256k(bootstrap)ro,512k(uboot)ro,256k(env),256k(env_redundant),256k(spare),512k(dtb),6M(kernel)ro,-(rootfs) root=/dev/mtdblock7 rw rootfstype=jffs2"
+CONFIG_LOGLEVEL=4
 # CONFIG_DISPLAY_BOARDINFO is not set
 CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_SPL=y

configs/omapl138_lcdk_defconfig

@@ -8,6 +8,7 @@ CONFIG_SPL_MMC_SUPPORT=y
 CONFIG_SPL_SERIAL_SUPPORT=y
 CONFIG_SPL_NAND_SUPPORT=y
 CONFIG_BOOTDELAY=3
+CONFIG_LOGLEVEL=4
 CONFIG_VERSION_VARIABLE=y
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_DISPLAY_BOARDINFO is not set

configs/openrd_base_defconfig

@@ -5,6 +5,7 @@ CONFIG_TARGET_OPENRD=y
 CONFIG_IDENT_STRING="\nOpenRD-Base"
 CONFIG_SYS_EXTRA_OPTIONS="BOARD_IS_OPENRD_BASE"
 CONFIG_BOOTDELAY=3
+CONFIG_LOGLEVEL=3
 # CONFIG_DISPLAY_BOARDINFO is not set
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set

configs/openrd_client_defconfig

@@ -5,6 +5,7 @@ CONFIG_TARGET_OPENRD=y
 CONFIG_IDENT_STRING="\nOpenRD-Client"
 CONFIG_SYS_EXTRA_OPTIONS="BOARD_IS_OPENRD_CLIENT"
 CONFIG_BOOTDELAY=3
+CONFIG_LOGLEVEL=3
 # CONFIG_DISPLAY_BOARDINFO is not set
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set

configs/openrd_ultimate_defconfig

@@ -5,6 +5,7 @@ CONFIG_TARGET_OPENRD=y
 CONFIG_IDENT_STRING="\nOpenRD-Ultimate"
 CONFIG_SYS_EXTRA_OPTIONS="BOARD_IS_OPENRD_ULTIMATE"
 CONFIG_BOOTDELAY=3
+CONFIG_LOGLEVEL=3
 # CONFIG_DISPLAY_BOARDINFO is not set
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set

configs/taurus_defconfig

@@ -16,6 +16,7 @@ CONFIG_SPL_SPI_SUPPORT=y
 CONFIG_DEFAULT_DEVICE_TREE="at91sam9g20-taurus"
 CONFIG_SYS_EXTRA_OPTIONS="AT91SAM9G20,MACH_TYPE=2067,BOARD_TAURUS"
 CONFIG_BOOTDELAY=3
+CONFIG_LOGLEVEL=4
 CONFIG_USE_BOOTARGS=y
 CONFIG_BOOTARGS="console=ttyS0,115200 earlyprintk mtdparts=atmel_nand:256k(bootstrap)ro,512k(uboot)ro,256k(env),256k(env_redundant),256k(spare),512k(dtb),6M(kernel)ro,-(rootfs) root=/dev/mtdblock7 rw rootfstype=jffs2"
 # CONFIG_DISPLAY_BOARDINFO is not set

configs/vf610twr_defconfig

@@ -3,6 +3,7 @@ CONFIG_ARCH_VF610=y
 CONFIG_DEFAULT_DEVICE_TREE="vf610-twr"
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=board/freescale/vf610twr/imximage.cfg"
 CONFIG_BOOTDELAY=3
+CONFIG_LOGLEVEL=3
 CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_HUSH_PARSER=y
 CONFIG_CMD_BOOTZ=y

configs/vf610twr_nand_defconfig

@@ -3,6 +3,7 @@ CONFIG_ARCH_VF610=y
 CONFIG_DEFAULT_DEVICE_TREE="vf610-twr"
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=board/freescale/vf610twr/imximage.cfg"
 CONFIG_BOOTDELAY=3
+CONFIG_LOGLEVEL=3
 CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_HUSH_PARSER=y
 CONFIG_CMD_BOOTZ=y