kernel.h: split out COUNT_ARGS() and CONCATENATE() to args.h

Patch series "kernel.h: Split out a couple of macros to args.h", v4.

There are macros in kernel.h that can be used outside of that header.
Split them to args.h and replace open coded variants.

This patch (of 4):

kernel.h is being used as a dump for all kinds of stuff for a long time.
The COUNT_ARGS() and CONCATENATE() macros may be used in some places
without need of the full kernel.h dependency train with it.

Here is the attempt on cleaning it up by splitting out these macros().

While at it, include new header where it's being used.

Link: https://lkml.kernel.org/r/20230718211147.18647-1-andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20230718211147.18647-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>	[PCI]
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Gow <davidgow@google.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/kunit/test.h b/include/kunit/test.h
index 23120d50499efd63af3db07d13f6cf0136f73315..107c814316345b58598e4a57d131932f28085a34 100644 (file)
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -12,6 +12,7 @@
 #include <kunit/assert.h>
 #include <kunit/try-catch.h>
 
+#include <linux/args.h>
 #include <linux/compiler.h>
 #include <linux/container_of.h>
 #include <linux/err.h>

diff --git a/include/linux/args.h b/include/linux/args.h
new file mode 100644 (file)
index 0000000..8ff60a5
--- /dev/null
+++ b/include/linux/args.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _LINUX_ARGS_H
+#define _LINUX_ARGS_H
+
+/*
+ * How do these macros work?
+ *
+ * In __COUNT_ARGS() _0 to _12 are just placeholders from the start
+ * in order to make sure _n is positioned over the correct number
+ * from 12 to 0 (depending on X, which is a variadic argument list).
+ * They serve no purpose other than occupying a position. Since each
+ * macro parameter must have a distinct identifier, those identifiers
+ * are as good as any.
+ *
+ * In COUNT_ARGS() we use actual integers, so __COUNT_ARGS() returns
+ * that as _n.
+ */
+
+/* This counts to 12. Any more, it will return 13th argument. */
+#define __COUNT_ARGS(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _n, X...) _n
+#define COUNT_ARGS(X...) __COUNT_ARGS(, ##X, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
+
+/* Concatenate two parameters, but allow them to be expanded beforehand. */
+#define __CONCAT(a, b) a ## b
+#define CONCATENATE(a, b) __CONCAT(a, b)
+
+#endif /* _LINUX_ARGS_H */

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 0d91e0af01250c1d82f4a2ea562d2619b9cc6e9c..b9e76f717a7e5e05ba8ce0f5407d3315c07f1828 100644 (file)
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -457,13 +457,6 @@ ftrace_vprintk(const char *fmt, va_list ap)
 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
 #endif /* CONFIG_TRACING */
 
-/* This counts to 12. Any more, it will return 13th argument. */
-#define __COUNT_ARGS(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _n, X...) _n
-#define COUNT_ARGS(X...) __COUNT_ARGS(, ##X, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
-
-#define __CONCAT(a, b) a ## b
-#define CONCATENATE(a, b) __CONCAT(a, b)
-
 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD

diff --git a/include/linux/pci.h b/include/linux/pci.h
index c69a2cc1f412347edf7ab2780a10ca5b2b1a3e1c..9c856e9aada5fbc7a2704ef690de7461681aaa55 100644 (file)
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -23,7 +23,7 @@
 #ifndef LINUX_PCI_H
 #define LINUX_PCI_H
 
-
+#include <linux/args.h>
 #include <linux/mod_devicetable.h>
 
 #include <linux/types.h>

diff --git a/include/trace/bpf_probe.h b/include/trace/bpf_probe.h
index 1f7fc1fc590c11587a3c7f4d16d60d61ccb52469..e609cd7da47e8e71af2ed69a5630cf6913aa423d 100644 (file)
--- a/include/trace/bpf_probe.h
+++ b/include/trace/bpf_probe.h
@@ -12,6 +12,8 @@
 #undef __perf_task
 #define __perf_task(t) (t)
 
+#include <linux/args.h>
+
 /* cast any integer, pointer, or small struct to u64 */
 #define UINTTYPE(size) \
        __typeof__(__builtin_choose_expr(size == 1,  (u8)1, \