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-rw-r--r--include/linux/dynamic_printk.h93
1 files changed, 93 insertions, 0 deletions
diff --git a/include/linux/dynamic_printk.h b/include/linux/dynamic_printk.h
new file mode 100644
index 000000000000..2d528d009074
--- /dev/null
+++ b/include/linux/dynamic_printk.h
@@ -0,0 +1,93 @@
+#ifndef _DYNAMIC_PRINTK_H
+#define _DYNAMIC_PRINTK_H
+
+#define DYNAMIC_DEBUG_HASH_BITS 6
+#define DEBUG_HASH_TABLE_SIZE (1 << DYNAMIC_DEBUG_HASH_BITS)
+
+#define TYPE_BOOLEAN 1
+
+#define DYNAMIC_ENABLED_ALL 0
+#define DYNAMIC_ENABLED_NONE 1
+#define DYNAMIC_ENABLED_SOME 2
+
+extern int dynamic_enabled;
+
+/* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which
+ * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They
+ * use independent hash functions, to reduce the chance of false positives.
+ */
+extern long long dynamic_printk_enabled;
+extern long long dynamic_printk_enabled2;
+
+struct mod_debug {
+ char *modname;
+ char *logical_modname;
+ char *flag_names;
+ int type;
+ int hash;
+ int hash2;
+} __attribute__((aligned(8)));
+
+int register_dynamic_debug_module(char *mod_name, int type, char *share_name,
+ char *flags, int hash, int hash2);
+
+#if defined(CONFIG_DYNAMIC_PRINTK_DEBUG)
+extern int unregister_dynamic_debug_module(char *mod_name);
+extern int __dynamic_dbg_enabled_helper(char *modname, int type,
+ int value, int hash);
+
+#define __dynamic_dbg_enabled(module, type, value, level, hash) ({ \
+ int __ret = 0; \
+ if (unlikely((dynamic_printk_enabled & (1LL << DEBUG_HASH)) && \
+ (dynamic_printk_enabled2 & (1LL << DEBUG_HASH2)))) \
+ __ret = __dynamic_dbg_enabled_helper(module, type, \
+ value, hash);\
+ __ret; })
+
+#define dynamic_pr_debug(fmt, ...) do { \
+ static char mod_name[] \
+ __attribute__((section("__verbose_strings"))) \
+ = KBUILD_MODNAME; \
+ static struct mod_debug descriptor \
+ __used \
+ __attribute__((section("__verbose"), aligned(8))) = \
+ { mod_name, mod_name, NULL, TYPE_BOOLEAN, DEBUG_HASH, DEBUG_HASH2 };\
+ if (__dynamic_dbg_enabled(KBUILD_MODNAME, TYPE_BOOLEAN, \
+ 0, 0, DEBUG_HASH)) \
+ printk(KERN_DEBUG KBUILD_MODNAME ":" fmt, \
+ ##__VA_ARGS__); \
+ } while (0)
+
+#define dynamic_dev_dbg(dev, format, ...) do { \
+ static char mod_name[] \
+ __attribute__((section("__verbose_strings"))) \
+ = KBUILD_MODNAME; \
+ static struct mod_debug descriptor \
+ __used \
+ __attribute__((section("__verbose"), aligned(8))) = \
+ { mod_name, mod_name, NULL, TYPE_BOOLEAN, DEBUG_HASH, DEBUG_HASH2 };\
+ if (__dynamic_dbg_enabled(KBUILD_MODNAME, TYPE_BOOLEAN, \
+ 0, 0, DEBUG_HASH)) \
+ dev_printk(KERN_DEBUG, dev, \
+ KBUILD_MODNAME ": " format, \
+ ##__VA_ARGS__); \
+ } while (0)
+
+#else
+
+static inline int unregister_dynamic_debug_module(const char *mod_name)
+{
+ return 0;
+}
+static inline int __dynamic_dbg_enabled_helper(char *modname, int type,
+ int value, int hash)
+{
+ return 0;
+}
+
+#define __dynamic_dbg_enabled(module, type, value, level, hash) ({ 0; })
+#define dynamic_pr_debug(fmt, ...) do { } while (0)
+#define dynamic_dev_dbg(dev, format, ...) do { } while (0)
+#endif
+
+#endif