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X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org 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. V2: I've taken on this series as there isn't any response from Jisheng. No significant changes other than build fixes. - Fixes build breakage in patch 3 to do with not having used 'goto' keyword. - Fixes build breakage in patch 4 on 32bit not having delcared __ptr in the macro. V3: Significant commit message rewrites. - Corrected the justification for patch 2 - Better explained/justified patches 3 and 4 Minor code changes for legibility and more comments V4: Fixed checkpatch errors Added a unsafe_copy_from_user() Added patch from Ben Dooks to save SR_SUM bit on switch Ben Dooks (1): riscv: save the SR_SUM status over switches Jisheng Zhang (4): riscv: implement user_access_begin() and families riscv: uaccess: use input constraints for ptr of __put_user() riscv: uaccess: use 'asm goto' for put_user() riscv: uaccess: use 'asm_goto_output' for get_user() arch/riscv/include/asm/processor.h | 1 + arch/riscv/include/asm/uaccess.h | 218 ++++++++++++++++++++++------- arch/riscv/kernel/asm-offsets.c | 5 + arch/riscv/kernel/entry.S | 8 ++ 4 files changed, 179 insertions(+), 53 deletions(-)