The newly introduced GENMASK_TYPE() macro can also be used to generate
the pre-existing non-asm GENMASK*() variants.

Apply GENMASK_TYPE() to GENMASK(), GENMASK_ULL() and GENMASK_U128().

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>

In an upcoming change, the non-asm GENMASK*() will all be unified to
depend on GENMASK_TYPE() which indirectly depend on sizeof(), something
not available in asm.

Instead of adding further complexity to GENMASK_TYPE() to make it work
for both asm and non asm, just split the definition of the two variants.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>

Implement fixed-type BIT_U*() to help drivers add stricter checks,
like it was done for GENMASK_U*().

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Co-developed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

Add GENMASK_TYPE() which generalizes __GENMASK() to support different
types, and implement fixed-types versions of GENMASK() based on it.
The fixed-type version allows more strict checks to the min/max values
accepted, which is useful for defining registers like implemented by
i915 and xe drivers with their REG_GENMASK*() macros.

The strict checks rely on shift-count-overflow compiler check to fail
the build if a number outside of the range allowed is passed.
Example:

  #define FOO_MASK GENMASK_U32(33, 4)

will generate a warning like:

  include/linux/bits.h:51:27: error: right shift count >= width of type [-Werror=shift-count-overflow]
     51 |               type_max(t) >> (BITS_PER_TYPE(t) - 1 - (h)))))
        |                           ^~

The result is casted to the corresponding fixed width type. For
example, GENMASK_U8() returns an u8. Note that because of the C
promotion rules, GENMASK_U8() and GENMASK_U16() will immediately be
promoted to int if used in an expression. Regardless, the main goal is
not to get the correct type, but rather to enforce more checks at
compile time.

While GENMASK_TYPE() is crafted to cover all variants, including the
already existing GENMASK(), GENMASK_ULL() and GENMASK_U128(), for the
moment, only use it for the newly introduced GENMASK_U*(). The
consolidation will be done in a separate change.

Co-developed-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

This is a preparation for the upcoming GENMASK_U*() and BIT_U*()
changes. After introducing those new macros, there will be a lot of
scrolling between the #if, #else and #endif.

Add a comment to the #else and #endif preprocessor macros to help keep
track of which context we are in. Also, add new lines to better
visually separate the non-asm and asm sections.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

"int" was misspelled as "init" the code comments in the bits.h and
const.h files. Fix the typo.

CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

In GENMASK_INPUT_CHECK(),

  __builtin_choose_expr(__is_constexpr((l) > (h)), (l) > (h), 0)

is the exact expansion of:

  const_true((l) > (h))

Apply const_true() to simplify GENMASK_INPUT_CHECK().

CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Rasmus Villemoes <linux@rasmusvillemoes.dk>
CC: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Reviewed-by: Yury Norov <yury.norov@gmail.com>,
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

This adds GENMASK_U128() and __GENMASK_U128() macros using __BITS_PER_U128
and __int128 data types. These macros will be used in providing support for
generating 128 bit masks.

The macros wouldn't work in all assembler flavors for reasons described
in the comments on top of declarations. Enforce it for more by adding
!__ASSEMBLY__ guard.

Cc: Yury Norov <yury.norov@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Arnd Bergmann <arnd@arndb.de>>
Cc: linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

Move __GENMASK and __GENMASK_ULL from include/ to include/uapi/ so that they can
be used to define masks in userspace API headers.  Compared to what is already
in include/linux/bits.h, the definitions need to use the uglified versions of
UL(), ULL(), BITS_PER_LONG and BITS_PER_LONG_LONG (which did not even exist),
but otherwise expand to the same content.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

The minimization done in 3945ff37d2f4 ("linux/bits.h: Extract common header
for vDSO") was required to isolate the VDSO build from the larger kernel
header impact.

The split added some inconsistency since BIT() and BIT_ULL() are now
defined in the different files which confuses unprepared reader.

Move BIT_ULL() to vdso/bits.h. No functional change.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20221128141003.77929-1-andriy.shevchenko@linux.intel.com