[PATCH 1/2] moduleparams: Add hex type parameter

[Paul Menzel <pmenzel@molgen.mpg.de>]

For bitmasks printing values in hex is more convenient.

Prefix with 0x (#) to make it clear, that it’s a hex value.

Using the helper for `amdgpu.ppfeaturemask`, it will look like below.

Before:

    $ more /sys/module/amdgpu/parameters/ppfeaturemask
    4294950911

After:

    $ more /sys/module/amdgpu/parameters/ppfeaturemask
    0xffffbfff

Cc: linux-kernel@vger.kernel.org
Cc: amd-gfx@lists.freedesktop.org
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
---
 include/linux/moduleparam.h | 7 ++++++-
 kernel/params.c             | 1 +
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index 3ef917ff0964..408978fcfe27 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -118,7 +118,7 @@ struct kparam_array
  * you can create your own by defining those variables.
  *
  * Standard types are:
- *	byte, short, ushort, int, uint, long, ulong
+ *	byte, hex, short, ushort, int, uint, long, ulong
  *	charp: a character pointer
  *	bool: a bool, values 0/1, y/n, Y/N.
  *	invbool: the above, only sense-reversed (N = true).
@@ -448,6 +448,11 @@ extern int param_set_ullong(const char *val, const struct kernel_param *kp);
 extern int param_get_ullong(char *buffer, const struct kernel_param *kp);
 #define param_check_ullong(name, p) __param_check(name, p, unsigned long long)
 
+extern const struct kernel_param_ops param_ops_hex;
+extern int param_set_hex(const char *val, const struct kernel_param *kp);
+extern int param_get_hex(char *buffer, const struct kernel_param *kp);
+#define param_check_hex(name, p) param_check_uint(name, p)
+
 extern const struct kernel_param_ops param_ops_charp;
 extern int param_set_charp(const char *val, const struct kernel_param *kp);
 extern int param_get_charp(char *buffer, const struct kernel_param *kp);
diff --git a/kernel/params.c b/kernel/params.c
index 8e56f8b12d8f..ceca8394dac5 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -241,6 +241,7 @@ STANDARD_PARAM_DEF(uint,	unsigned int,		"%u",   kstrtouint);
 STANDARD_PARAM_DEF(long,	long,			"%li",  kstrtol);
 STANDARD_PARAM_DEF(ulong,	unsigned long,		"%lu",  kstrtoul);
 STANDARD_PARAM_DEF(ullong,	unsigned long long,	"%llu", kstrtoull);
+STANDARD_PARAM_DEF(hex,		unsigned int,		"%#x",  kstrtouint);
 
 int param_set_charp(const char *val, const struct kernel_param *kp)
 {
-- 
2.26.2