Re: [PATCH v3 0/3] serial: Add RISC-V support to the earlycon semihost driver

From: Sergey Matyukevich <geomatsi@gmail.com>
To: Bin Meng <bmeng@tinylab.org>
Cc: linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org,
	linux-serial@vger.kernel.org, Albert Ou <aou@eecs.berkeley.edu>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jirislaby@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Russell King <linux@armlinux.org.uk>,
	Will Deacon <will@kernel.org>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v3 0/3] serial: Add RISC-V support to the earlycon semihost driver
Date: Thu, 22 Dec 2022 23:06:23 +0300	[thread overview]
Message-ID: <Y6S4v7t0n0BI1P7d@curiosity> (raw)
In-Reply-To: <20221209150437.795918-1-bmeng@tinylab.org>

Hi Bin,

> RISC-V semihosting spec [1] is built on top of the existing Arm one;
> we can add RISC-V earlycon semihost driver easily.
> 
> This series refactors the existing driver a little bit, to move smh_putc()
> variants in respective arch's semihost.h, then we can implement RISC-V's
> version in the riscv arch directory.
> 
> Link: https://github.com/riscv/riscv-semihosting-spec/blob/main/riscv-semihosting-spec.adoc [1]
> 
> Changes in v3:
> - add #ifdef in the header to prevent from multiple inclusion
> - add forward-declare struct uart_port
> - add a Link tag in the commit message
> 
> Changes in v2:
> - new patch: "serial: earlycon-arm-semihost: Move smh_putc() variants in respective arch's semihost.h"
> - Move the RISC-V implementation to semihost.h
> 
> Bin Meng (3):
>   serial: earlycon-arm-semihost: Move smh_putc() variants in respective
>     arch's semihost.h
>   riscv: Implement semihost.h for earlycon semihost driver
>   serial: Rename earlycon semihost driver
> 
>  arch/arm/include/asm/semihost.h               | 30 +++++++++++++++++++
>  arch/arm64/include/asm/semihost.h             | 24 +++++++++++++++
>  arch/riscv/include/asm/semihost.h             | 26 ++++++++++++++++
>  drivers/tty/serial/Kconfig                    | 14 ++++-----
>  drivers/tty/serial/Makefile                   |  2 +-
>  ...con-arm-semihost.c => earlycon-semihost.c} | 25 +---------------
>  6 files changed, 89 insertions(+), 32 deletions(-)
>  create mode 100644 arch/arm/include/asm/semihost.h
>  create mode 100644 arch/arm64/include/asm/semihost.h
>  create mode 100644 arch/riscv/include/asm/semihost.h
>  rename drivers/tty/serial/{earlycon-arm-semihost.c => earlycon-semihost.c} (57%)

Tested-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com>

Applied the patches on top of Linux 6.1 and tested earlycon logs from
RISC-V target in OpenOCD.

Regards,
Sergey