[PATCH v3 00/11] Enable setexpr command to print cpu-list like bitmaps

[lukas.funke-oss at weidmueller.com]

From: Lukas Funke <lukas.funke at weidmueller.com>


This series enables the 'setexpr' command to print "cpu list"-like
bitmaps based on the printk format specifier [1].

One use-case is to pass cpu list [2] based kernel parameter like
'isolcpu', 'nohz_full', irq affinity or RCU related CPU parameter to
the kernel via a separate firmware variable without exposing the
'bootargs' variable to directly.

Example:

=> env set value 0xdeadbeef
=> setexpr a fmt isolcpus=%32pbl $value
=> echo $a
isolcpus=0-3,5-7,9-13,15-16,18-19,21,23,25-28,30-31

[1] https://www.kernel.org/doc/Documentation/printk-formats.txt
[2] https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html


Changes in v3:
- Use generic find_next_zero_bit() from arch/arm/include/asm/bitops.h
- Redirect sandbox ffz() implementation to generic __ffs() impl
- Remove '%bp' from documentation
- Give an example output in the documentation
- Remove bitmap_string() conversion function since the same function
  can be achieved using other format specifier
- Dereference pointer argument (i.e. *value) in the
  'setexpr name fmt <format> value' case. This is currently only
  supported in the 'setexptr <name> [*]<value>' and
  'setexptr <name> [*]<value> <op> [*]<value2>' case

Changes in v2:
- Add bitmap format specifier to documentation

Lukas Funke (11):
  sandbox: add generic find_next_zero_bit implementation
  linux: bitmap.h: add 'for_each_set_bitrange' iteration macro
  test: cmd: setexpr: Add tests for bitmap string format
  doc: printf() codes: Add bitmap format specifier
  cmd: printf: Correctly handle field width
  lib: Add hextobarray() function
  lib: vsprintf: enable '%pbl' format specifier
  setexpr: rename 'get_arg()' to 'setexpr_get_arg()'
  setexpr: Promote 'setexpr_get_arg()' to a public function
  setexptr: Extend setexpr_get_arg() to handle pointer to memory
  cmd: printf: forward '%p' format string specifier

 arch/sandbox/include/asm/bitops.h | 60 +++++++++++++++++++------------
 cmd/printf.c                      | 53 ++++++++++++++++++++++++++-
 cmd/setexpr.c                     | 48 +++++++++++++++----------
 doc/develop/printf.rst            |  4 +++
 include/command.h                 | 27 ++++++++++++++
 include/linux/bitmap.h            |  7 ++++
 include/vsprintf.h                |  7 ++++
 lib/strto.c                       | 35 ++++++++++++++++++
 lib/vsprintf.c                    | 42 ++++++++++++++++++++++
 test/cmd/setexpr.c                | 22 ++++++++++++
 10 files changed, 263 insertions(+), 42 deletions(-)

-- 
2.30.2