svn commit: r362794 - head/sys/compat/linuxkpi/common/include/linux

[Ravi Pokala]

Thank you!

-Ravi (rpokala@)


-----Original Message-----
From: <owner-src-committers at freebsd.org> on behalf of Hans Petter Selasky <hselasky at FreeBSD.org>
Date: 2020-06-30, Tuesday at 01:41
To: <src-committers at freebsd.org>, <svn-src-all at freebsd.org>, <svn-src-head at freebsd.org>
Subject: svn commit: r362794 - head/sys/compat/linuxkpi/common/include/linux

    Author: hselasky
    Date: Tue Jun 30 08:41:33 2020
    New Revision: 362794
    URL: https://svnweb.freebsd.org/changeset/base/362794

    Log:
      Document the is_signed(), type_max() and type_min() function macros in the
      LinuxKPI. Try to make the function argument more readable.

      Suggested by:	several
      MFC after:	1 week
      Sponsored by:	Mellanox Technologies

    Modified:
      head/sys/compat/linuxkpi/common/include/linux/kernel.h

    Modified: head/sys/compat/linuxkpi/common/include/linux/kernel.h
    ==============================================================================
    --- head/sys/compat/linuxkpi/common/include/linux/kernel.h	Tue Jun 30 07:37:24 2020	(r362793)
    +++ head/sys/compat/linuxkpi/common/include/linux/kernel.h	Tue Jun 30 08:41:33 2020	(r362794)
    @@ -564,20 +564,33 @@ linux_ratelimited(linux_ratelimit_t *rl)
     #define	__is_constexpr(x) \
     	__builtin_constant_p(x)

    -#define	is_signed(x) (((x)-1 / (x)2) == (x)0)
    +/*
    + * The is_signed() macro below returns true if the passed data type is
    + * signed. Else false is returned.
    + */
    +#define	is_signed(datatype) (((datatype)-1 / (datatype)2) == (datatype)0)

    -#define	type_max(x) (						\
    -  (sizeof(x) >= 8) ? (is_signed(x) ? INT64_MAX : UINT64_MAX) :	\
    -  (sizeof(x) >= 4) ? (is_signed(x) ? INT32_MAX : UINT32_MAX) :	\
    -  (sizeof(x) >= 2) ? (is_signed(x) ? INT16_MAX : UINT16_MAX) :	\
    -		     (is_signed(x) ? INT8_MAX : UINT8_MAX)	\
    +/*
    + * The type_max() macro below returns the maxium positive value the
    + * passed data type can hold.
    + */
    +#define	type_max(datatype) ( \
    +  (sizeof(datatype) >= 8) ? (is_signed(datatype) ? INT64_MAX : UINT64_MAX) : \
    +  (sizeof(datatype) >= 4) ? (is_signed(datatype) ? INT32_MAX : UINT32_MAX) : \
    +  (sizeof(datatype) >= 2) ? (is_signed(datatype) ? INT16_MAX : UINT16_MAX) : \
    +			    (is_signed(datatype) ? INT8_MAX : UINT8_MAX) \
     )

    -#define	type_min(x) (					\
    -  (sizeof(x) >= 8) ? (is_signed(x) ? INT64_MIN : 0) :	\
    -  (sizeof(x) >= 4) ? (is_signed(x) ? INT32_MIN : 0) :	\
    -  (sizeof(x) >= 2) ? (is_signed(x) ? INT16_MIN : 0) :	\
    -		     (is_signed(x) ? INT8_MIN : 0)	\
    +/*
    + * The type_min() macro below returns the minimum value the passed
    + * data type can hold. For unsigned types the minimum value is always
    + * zero. For signed types it may vary.
    + */
    +#define	type_min(datatype) ( \
    +  (sizeof(datatype) >= 8) ? (is_signed(datatype) ? INT64_MIN : 0) : \
    +  (sizeof(datatype) >= 4) ? (is_signed(datatype) ? INT32_MIN : 0) : \
    +  (sizeof(datatype) >= 2) ? (is_signed(datatype) ? INT16_MIN : 0) : \
    +			    (is_signed(datatype) ? INT8_MIN : 0) \
     )

     #endif	/* _LINUX_KERNEL_H_ */