1d4ce389da
In ice_ptp_cfg_clkout(), the ice driver needs to calculate the nearest next second of a current time value specified in nanoseconds. It implements this using div64_u64, because the time value is a u64. It could use div_u64 since NSEC_PER_SEC is smaller than 32-bits. Ideally this would be implemented directly with roundup(), but that can't work on all platforms due to a division which requires using the specific macros and functions due to platform restrictions, and to ensure that the most appropriate and fast instructions are used. The kernel doesn't currently provide any 64-bit equivalents for doing roundup. Attempting to use roundup() on a 32-bit platform will result in a link failure due to not having a direct 64-bit division. The closest equivalent for this is DIV64_U64_ROUND_UP, which does a division always rounding up. However, this only computes the division, and forces use of the div64_u64 in cases where the divisor is a 32bit value and could make use of div_u64. Introduce DIV_U64_ROUND_UP based on div_u64, and then use it to implement roundup_u64 which takes a u64 input value and a u32 rounding value. The name roundup_u64 matches the naming scheme of div_u64, and future patches could implement roundup64_u64 if they need to round by a multiple that is greater than 32-bits. Replace the logic in ice_ptp.c which does this equivalent with the newly added roundup_u64. Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Link: https://lore.kernel.org/r/20240607-next-2024-06-03-intel-next-batch-v3-2-d1470cee3347@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.