v4.19.13 snapshot.
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
new file mode 100644
index 0000000..2fd8006
--- /dev/null
+++ b/include/linux/dynamic_debug.h
@@ -0,0 +1,186 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _DYNAMIC_DEBUG_H
+#define _DYNAMIC_DEBUG_H
+
+#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
+#include <linux/jump_label.h>
+#endif
+
+/*
+ * An instance of this structure is created in a special
+ * ELF section at every dynamic debug callsite. At runtime,
+ * the special section is treated as an array of these.
+ */
+struct _ddebug {
+ /*
+ * These fields are used to drive the user interface
+ * for selecting and displaying debug callsites.
+ */
+ const char *modname;
+ const char *function;
+ const char *filename;
+ const char *format;
+ unsigned int lineno:18;
+ /*
+ * The flags field controls the behaviour at the callsite.
+ * The bits here are changed dynamically when the user
+ * writes commands to <debugfs>/dynamic_debug/control
+ */
+#define _DPRINTK_FLAGS_NONE 0
+#define _DPRINTK_FLAGS_PRINT (1<<0) /* printk() a message using the format */
+#define _DPRINTK_FLAGS_INCL_MODNAME (1<<1)
+#define _DPRINTK_FLAGS_INCL_FUNCNAME (1<<2)
+#define _DPRINTK_FLAGS_INCL_LINENO (1<<3)
+#define _DPRINTK_FLAGS_INCL_TID (1<<4)
+#if defined DEBUG
+#define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT
+#else
+#define _DPRINTK_FLAGS_DEFAULT 0
+#endif
+ unsigned int flags:8;
+#ifdef HAVE_JUMP_LABEL
+ union {
+ struct static_key_true dd_key_true;
+ struct static_key_false dd_key_false;
+ } key;
+#endif
+} __attribute__((aligned(8)));
+
+
+int ddebug_add_module(struct _ddebug *tab, unsigned int n,
+ const char *modname);
+
+#if defined(CONFIG_DYNAMIC_DEBUG)
+extern int ddebug_remove_module(const char *mod_name);
+extern __printf(2, 3)
+void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
+
+extern int ddebug_dyndbg_module_param_cb(char *param, char *val,
+ const char *modname);
+
+struct device;
+
+extern __printf(3, 4)
+void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev,
+ const char *fmt, ...);
+
+struct net_device;
+
+extern __printf(3, 4)
+void __dynamic_netdev_dbg(struct _ddebug *descriptor,
+ const struct net_device *dev,
+ const char *fmt, ...);
+
+#define DEFINE_DYNAMIC_DEBUG_METADATA_KEY(name, fmt, key, init) \
+ static struct _ddebug __aligned(8) \
+ __attribute__((section("__verbose"))) name = { \
+ .modname = KBUILD_MODNAME, \
+ .function = __func__, \
+ .filename = __FILE__, \
+ .format = (fmt), \
+ .lineno = __LINE__, \
+ .flags = _DPRINTK_FLAGS_DEFAULT, \
+ dd_key_init(key, init) \
+ }
+
+#ifdef HAVE_JUMP_LABEL
+
+#define dd_key_init(key, init) key = (init)
+
+#ifdef DEBUG
+#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
+ DEFINE_DYNAMIC_DEBUG_METADATA_KEY(name, fmt, .key.dd_key_true, \
+ (STATIC_KEY_TRUE_INIT))
+
+#define DYNAMIC_DEBUG_BRANCH(descriptor) \
+ static_branch_likely(&descriptor.key.dd_key_true)
+#else
+#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
+ DEFINE_DYNAMIC_DEBUG_METADATA_KEY(name, fmt, .key.dd_key_false, \
+ (STATIC_KEY_FALSE_INIT))
+
+#define DYNAMIC_DEBUG_BRANCH(descriptor) \
+ static_branch_unlikely(&descriptor.key.dd_key_false)
+#endif
+
+#else
+
+#define dd_key_init(key, init)
+
+#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt) \
+ DEFINE_DYNAMIC_DEBUG_METADATA_KEY(name, fmt, 0, 0)
+
+#ifdef DEBUG
+#define DYNAMIC_DEBUG_BRANCH(descriptor) \
+ likely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
+#else
+#define DYNAMIC_DEBUG_BRANCH(descriptor) \
+ unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
+#endif
+
+#endif
+
+#define dynamic_pr_debug(fmt, ...) \
+do { \
+ DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
+ if (DYNAMIC_DEBUG_BRANCH(descriptor)) \
+ __dynamic_pr_debug(&descriptor, pr_fmt(fmt), \
+ ##__VA_ARGS__); \
+} while (0)
+
+#define dynamic_dev_dbg(dev, fmt, ...) \
+do { \
+ DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
+ if (DYNAMIC_DEBUG_BRANCH(descriptor)) \
+ __dynamic_dev_dbg(&descriptor, dev, fmt, \
+ ##__VA_ARGS__); \
+} while (0)
+
+#define dynamic_netdev_dbg(dev, fmt, ...) \
+do { \
+ DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
+ if (DYNAMIC_DEBUG_BRANCH(descriptor)) \
+ __dynamic_netdev_dbg(&descriptor, dev, fmt, \
+ ##__VA_ARGS__); \
+} while (0)
+
+#define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
+ groupsize, buf, len, ascii) \
+do { \
+ DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, \
+ __builtin_constant_p(prefix_str) ? prefix_str : "hexdump");\
+ if (DYNAMIC_DEBUG_BRANCH(descriptor)) \
+ print_hex_dump(KERN_DEBUG, prefix_str, \
+ prefix_type, rowsize, groupsize, \
+ buf, len, ascii); \
+} while (0)
+
+#else
+
+#include <linux/string.h>
+#include <linux/errno.h>
+
+static inline int ddebug_remove_module(const char *mod)
+{
+ return 0;
+}
+
+static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
+ const char *modname)
+{
+ if (strstr(param, "dyndbg")) {
+ /* avoid pr_warn(), which wants pr_fmt() fully defined */
+ printk(KERN_WARNING "dyndbg param is supported only in "
+ "CONFIG_DYNAMIC_DEBUG builds\n");
+ return 0; /* allow and ignore */
+ }
+ return -EINVAL;
+}
+
+#define dynamic_pr_debug(fmt, ...) \
+ do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
+#define dynamic_dev_dbg(dev, fmt, ...) \
+ do { if (0) dev_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__); } while (0)
+#endif
+
+#endif