From: Palmer Dabbelt <palmer@rivosinc.com>
Date: Thu, 8 May 2025 17:01:02 +0000 (-0700)
Subject: Merge patch series "riscv: uaccess: optimisations"
X-Git-Tag: v6.16-rc1~18^2~9
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=259aaf03d7a03fe3c2f909deaeea7ce84ed47880;p=thirdparty%2Fkernel%2Flinux.git

Merge patch series "riscv: uaccess: optimisations"

Cyril Bur <cyrilbur@tenstorrent.com> says:

This series tries to optimize riscv uaccess by allowing the use of
user_access_begin() and user_access_end() which permits grouping user accesses
and avoiding the CSR write penalty for each access.

The error path can also be optimised using asm goto which patches 3 and 4
achieve. This will speed up jumping to labels by avoiding the need of an
intermediary error type variable within the uaccess macros

I did read the discussion this series generated. It isn't clear to me
which direction to take the patches, if any.

* b4-shazam-merge:
  riscv: uaccess: use 'asm_goto_output' for get_user()
  riscv: uaccess: use 'asm goto' for put_user()
  riscv: uaccess: use input constraints for ptr of __put_user()
  riscv: implement user_access_begin() and families
  riscv: save the SR_SUM status over switches

Link: https://lore.kernel.org/r/20250410070526.3160847-1-cyrilbur@tenstorrent.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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259aaf03d7a03fe3c2f909deaeea7ce84ed47880