[PATCH v2 0/2] riscv: Use CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS to set misaligned access speed

Charlie Jenkins charlie at rivosinc.com
Thu Feb 1 15:30:44 PST 2024


If CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is enabled, no time needs to
be spent in the misaligned access speed probe. Disable the probe in this
case and set respective uses to "fast" misaligned accesses. On riscv,
this config is selected if RISCV_EFFICIENT_UNALIGNED_ACCESS is selected,
which is dependent on NONPORTABLE.

Signed-off-by: Charlie Jenkins <charlie at rivosinc.com>
---
Changes in v2:
- Move around definitions to reduce ifdefs (Clément)
- Make RISCV_MISALIGNED depend on !HAVE_EFFICIENT_UNALIGNED_ACCESS
  (Clément)
- Link to v1: https://lore.kernel.org/r/20240131-disable_misaligned_probe_config-v1-0-98d155e9cda8@rivosinc.com

---
Charlie Jenkins (2):
      riscv: lib: Introduce has_fast_misaligned_access function
      riscv: Disable misaligned access probe when CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS

 arch/riscv/Kconfig                               |   1 +
 arch/riscv/include/asm/cpufeature.h              |  22 +-
 arch/riscv/include/asm/misaligned_access_speed.h |  29 +++
 arch/riscv/kernel/Makefile                       |   3 +
 arch/riscv/kernel/cpufeature.c                   | 255 ----------------------
 arch/riscv/kernel/misaligned_access_speed.c      | 265 +++++++++++++++++++++++
 arch/riscv/kernel/sys_hwprobe.c                  |   4 +
 arch/riscv/lib/csum.c                            |   7 +-
 8 files changed, 321 insertions(+), 265 deletions(-)
---
base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d
change-id: 20240131-disable_misaligned_probe_config-043aea375f93
-- 
- Charlie




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