so could make subsys easy to add loglevel and xxx_printk
v2: make it more genric, so subsys user only need to two line macro
v3: add back nameStr, so could find out iommu: and iommu_gart: and etc
v4: use printk intead of pci_printk
v5: fix checkpatch error and warning
v6: add DEFINE_LOGLEVEL_SETUP_DEF to take default
v7: call tag_loglevel_setup only one time, so could take several loglevel like
loglevel=4 loglevel=acpi:8 loglevel=pci:8 loglevel=apic:8 is the same as
loglevel=4,acpi:8,pci:8,apic:8

usage:
in .h to have
#define KERN_PCI ""
in .c to have
DEFINE_LOGLEVEL_SETUP(pci, KERN_PCI, "pci:");
then could use
printk(KERN_DEBUG KERN_PCI fmt, ...);
and command line
loglevel=pci:8

you can add different printk to different files of one subsys if you like

Signed-off-by: Yinghai Lu
---
arch/x86/kernel/vmlinux_32.lds.S | 1
arch/x86/kernel/vmlinux_64.lds.S | 2
include/asm-generic/vmlinux.lds.h | 8 +++
include/linux/init.h | 22 ++++++++++
include/linux/kernel.h | 9 ++++
init/main.c | 77 +++++++++++++++++++++++++++++++++++++-
kernel/printk.c | 28 +++++++++++--
7 files changed, 142 insertions(+), 5 deletions(-)

Index: linux-2.6/arch/x86/kernel/vmlinux_32.lds.S
================================================== =================
--- linux-2.6.orig/arch/x86/kernel/vmlinux_32.lds.S
+++ linux-2.6/arch/x86/kernel/vmlinux_32.lds.S
@@ -145,6 +145,7 @@ SECTIONS
*(.x86_cpu_dev.init)
__x86_cpu_dev_end = .;
}
+ LOGLEVEL_SETUP_INIT(8)
DYN_ARRAY_INIT(8)
SECURITY_INIT
. = ALIGN(4);
Index: linux-2.6/arch/x86/kernel/vmlinux_64.lds.S
================================================== =================
--- linux-2.6.orig/arch/x86/kernel/vmlinux_64.lds.S
+++ linux-2.6/arch/x86/kernel/vmlinux_64.lds.S
@@ -174,6 +174,8 @@ SECTIONS
}
__x86_cpu_dev_end = .;

+ LOGLEVEL_SETUP_INIT(8)
+
DYN_ARRAY_INIT(8)

SECURITY_INIT
Index: linux-2.6/include/asm-generic/vmlinux.lds.h
================================================== =================
--- linux-2.6.orig/include/asm-generic/vmlinux.lds.h
+++ linux-2.6/include/asm-generic/vmlinux.lds.h
@@ -222,6 +222,14 @@
* All archs are supposed to use RO_DATA() */
#define RODATA RO_DATA(4096)

+#define LOGLEVEL_SETUP_INIT(align) \
+ . = ALIGN((align)); \
+ .loglevel_setup.init : AT(ADDR(.loglevel_setup.init) - LOAD_OFFSET) { \
+ VMLINUX_SYMBOL(__loglevel_setup_start) = .; \
+ *(.loglevel_setup.init) \
+ VMLINUX_SYMBOL(__loglevel_setup_end) = .; \
+ }
+
#define DYN_ARRAY_INIT(align) \
. = ALIGN((align)); \
.dyn_array.init : AT(ADDR(.dyn_array.init) - LOAD_OFFSET) { \
Index: linux-2.6/include/linux/init.h
================================================== =================
--- linux-2.6.orig/include/linux/init.h
+++ linux-2.6/include/linux/init.h
@@ -251,6 +251,28 @@ struct obs_kernel_param {
/* Relies on boot_command_line being set */
void __init parse_early_param(void);

+struct loglevel_setup {
+ char *name;
+ char *tag;
+ int level;
+};
+
+extern struct loglevel_setup *__loglevel_setup_start[], *__loglevel_setup_end[];
+
+#define DEFINE_LOGLEVEL_SETUP_DEF(nameX, tagX, nameStr, levelX) \
+ static struct loglevel_setup __loglevel_setup_##nameX __initdata = \
+ { \
+ .tag = tagX, \
+ .name = nameStr, \
+ .level = levelX, \
+ }; \
+ static struct loglevel_setup *__loglevel_setup_ptr_##nameX __used \
+ __attribute__((__section__(".loglevel_setup.init"))) = \
+ &__loglevel_setup_##nameX
+
+#define DEFINE_LOGLEVEL_SETUP(nameX, tagX, nameStr) \
+ DEFINE_LOGLEVEL_SETUP_DEF(nameX, tagX, nameStr, 0) \
+
struct dyn_array {
void **name;
unsigned long size;
Index: linux-2.6/include/linux/kernel.h
================================================== =================
--- linux-2.6.orig/include/linux/kernel.h
+++ linux-2.6/include/linux/kernel.h
@@ -104,6 +104,15 @@ extern int console_printk[];
#define minimum_console_loglevel (console_printk[2])
#define default_console_loglevel (console_printk[3])

+struct tag_console_loglevel {
+ char tag[32];
+ char name[32];
+ int level;
+};
+
+extern struct tag_console_loglevel tag_level[];
+extern int tag_level_nr;
+
struct completion;
struct pt_regs;
struct user;
Index: linux-2.6/init/main.c
================================================== =================
--- linux-2.6.orig/init/main.c
+++ linux-2.6/init/main.c
@@ -248,9 +248,79 @@ static int __init quiet_kernel(char *str
early_param("debug", debug_kernel);
early_param("quiet", quiet_kernel);

+struct tag_console_loglevel tag_level[32];
+int tag_level_nr;
+
+static int __init save_tag_name_level(const char *tag, const char *name,
+ int level)
+{
+ int len;
+
+ if (tag_level_nr > 32)
+ return -1;
+
+ len = sizeof(tag_level[tag_level_nr].tag);
+ strncpy(tag_level[tag_level_nr].tag, tag, len - 1);
+ len = sizeof(tag_level[tag_level_nr].name);
+ strncpy(tag_level[tag_level_nr].name, name, len - 1);
+ tag_level[tag_level_nr].level = level;
+
+ tag_level_nr++;
+
+ return 0;
+}
+
+static void __init tag_loglevel_setup(void)
+{
+ struct loglevel_setup **la;
+ int level = default_console_loglevel;
+
+ for (la = __loglevel_setup_start ; la < __loglevel_setup_end; la++) {
+ struct loglevel_setup *l = *la;
+
+ save_tag_name_level(l->tag, l->name, l->level ? : level);
+ }
+}
+
+static char __init *real_loglevel_setup(char *str)
+{
+ int i;
+
+ for (i = 0; i < tag_level_nr; i++) {
+ struct tag_console_loglevel *tl;
+ int len;
+
+ tl = &tag_level[i];
+ len = strlen(tl->name);
+ if (!strncmp(str, tl->name, len)) {
+ int level;
+
+ str += len;
+ get_option(&str, &level);
+ tl->level = level;
+ str = NULL;
+ break;
+ }
+ }
+
+ return str;
+}
+
static int __init loglevel(char *str)
{
- get_option(&str, &console_loglevel);
+ while (str) {
+ char *k = strchr(str, ',');
+
+ if (k)
+ *k++ = 0;
+ if (*str) {
+ str = real_loglevel_setup(str);
+ if (str && *str)
+ get_option(&str, &console_loglevel);
+ }
+ str = k;
+ }
+
return 0;
}

@@ -581,6 +651,7 @@ asmlinkage void __init start_kernel(void
page_address_init();
printk(KERN_NOTICE);
printk(linux_banner);
+ tag_loglevel_setup();
setup_arch(&command_line);
pre_alloc_dyn_array();
mm_init_owner(&init_mm, &init_task);
Index: linux-2.6/kernel/printk.c
================================================== =================
--- linux-2.6.orig/kernel/printk.c
+++ linux-2.6/kernel/printk.c
@@ -457,9 +457,9 @@ early_param("ignore_loglevel", ignore_lo
* Write out chars from start to end - 1 inclusive
*/
static void _call_console_drivers(unsigned start,
- unsigned end, int msg_log_level)
+ unsigned end, int msg_log_level, int level)
{
- if ((msg_log_level < console_loglevel || ignore_loglevel) &&
+ if ((msg_log_level < level || ignore_loglevel) &&
console_drivers && start != end) {
if ((start & LOG_BUF_MASK) > (end & LOG_BUF_MASK)) {
/* wrapped write */
@@ -481,21 +481,40 @@ static void call_console_drivers(unsigne
{
unsigned cur_index, start_print;
static int msg_level = -1;
+ int level = console_loglevel;

BUG_ON(((int)(start - end)) > 0);

cur_index = start;
start_print = start;
while (cur_index != end) {
+ int i;
+
if (msg_level < 0 && ((end - cur_index) > 2) &&
LOG_BUF(cur_index + 0) == '<' &&
LOG_BUF(cur_index + 1) >= '0' &&
LOG_BUF(cur_index + 1) <= '7' &&
LOG_BUF(cur_index + 2) == '>') {
msg_level = LOG_BUF(cur_index + 1) - '0';
+ level = console_loglevel;
cur_index += 3;
start_print = cur_index;
}
+ /* handle tag here */
+ for (i = 0; i < tag_level_nr; i++) {
+ struct tag_console_loglevel *tl;
+ int len;
+
+ tl = &tag_level[i];
+ len = strlen(tl->tag);
+ if ((end - cur_index) > (len - 1) &&
+ !strncmp(&LOG_BUF(cur_index), tl->tag, len)) {
+ level = tl->level;
+ cur_index += len;
+ start_print = cur_index;
+ break;
+ }
+ }
while (cur_index != end) {
char c = LOG_BUF(cur_index);

@@ -510,14 +529,15 @@ static void call_console_drivers(unsigne
*/
msg_level = default_message_loglevel;
}
- _call_console_drivers(start_print, cur_index, msg_level);
+ _call_console_drivers(start_print, cur_index,
+ msg_level, level);
msg_level = -1;
start_print = cur_index;
break;
}
}
}
- _call_console_drivers(start_print, end, msg_level);
+ _call_console_drivers(start_print, end, msg_level, level);
}

static void emit_log_char(char c)
--
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