On Sun, Jun 13, 2021 at 3:03 PM Marc Zyngier [off-list ref] wrote:

On Sat, 12 Jun 2021 17:04:16 +0100,
Anup Patel [off-list ref] wrote:

quoted

If IPI calls are injected using SBI IPI calls then remote TLB flush
using SBI RFENCE calls is much faster because using IPIs for remote
TLB flush would still endup as SBI IPI calls with extra processing
on kernel side.

It is now possible to have specialized hardware (such as RISC-V AIA)
which allows S-mode software to directly inject IPIs without any
assistance from M-mode runtime firmware.

This patch extends remote TLB flush functions to use IPIs whenever
underlying IPI operations are suitable for remote FENCEs.

Signed-off-by: Anup Patel <redacted>
---
 arch/riscv/mm/tlbflush.c | 62 +++++++++++++++++++++++++++++++---------
 1 file changed, 48 insertions(+), 14 deletions(-)

diff --git a/arch/riscv/mm/tlbflush.c b/arch/riscv/mm/tlbflush.c
index 720b443c4528..009c56fa102d 100644
--- a/arch/riscv/mm/tlbflush.c
+++ b/arch/riscv/mm/tlbflush.c

@@ -1,39 +1,73 @@
 // SPDX-License-Identifier: GPL-2.0
+/*
+ * TLB flush implementation.
+ *
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ */

I find this a bit odd. You don't mention this addition in the commit
message, and a quick look at the commits touching tlbflush.[ch]
doesn't make the copyright assignment obvious (most commits originate
from either SiFive or Christoph).

In any way, please keep this kind of changes out of this series if
possible, and have a separate discussion on who gets to brag about
this code.

I agree it's unrelated change.

The commit history suggest mm/tlbflush.c was added by Christoph
and other commits after that are from Atish (Western Digital).

I will sort this out separately.

Regards,
Anup

Thanks,

        M.

--
Without deviation from the norm, progress is not possible.