Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Heiko =?ISO-8859-1?Q?St=FCbner?= <heiko@sntech.de>
To:     Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Anup Patel <anup@brainfault.org>,
        Atish Patra <atishp@atishpatra.org>,
        Andrew Jones <ajones@ventanamicro.com>,
        Jisheng Zhang <jszhang@kernel.org>
Cc:     linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, kvm-riscv@lists.infradead.org,
        Conor Dooley <conor.dooley@microchip.com>
Subject: Re: [PATCH v2 02/13] riscv: move riscv_noncoherent_supported() out of ZICBOM probe
Date:   Sun, 04 Dec 2022 22:52:03 +0100
Message-ID: <5629547.DvuYhMxLoT@diego>
In-Reply-To: <20221204174632.3677-3-jszhang@kernel.org>
References: <20221204174632.3677-1-jszhang@kernel.org> <20221204174632.3677-3-jszhang@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 7Bit
Content-Type: text/plain; charset="us-ascii"
Precedence: bulk

Am Sonntag, 4. Dezember 2022, 18:46:21 CET schrieb Jisheng Zhang:
> It's a bit weird to call riscv_noncoherent_supported() each time when
> insmoding a module. Move the calling out of feature patch func.
> 
> Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
> Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
> Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
> ---
>  arch/riscv/kernel/cpufeature.c | 1 -
>  arch/riscv/kernel/setup.c      | 2 ++
>  2 files changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index c743f0adc794..364d1fe86bea 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -274,7 +274,6 @@ static bool __init_or_module cpufeature_probe_zicbom(unsigned int stage)
>  	if (!riscv_isa_extension_available(NULL, ZICBOM))
>  		return false;
>  
> -	riscv_noncoherent_supported();
>  	return true;
>  }
>  
> diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
> index 86acd690d529..6eea40bf8c6b 100644
> --- a/arch/riscv/kernel/setup.c
> +++ b/arch/riscv/kernel/setup.c
> @@ -300,6 +300,8 @@ void __init setup_arch(char **cmdline_p)
>  	riscv_init_cbom_blocksize();
>  	riscv_fill_hwcap();
>  	apply_boot_alternatives();
> +	if (riscv_isa_extension_available(NULL, ZICBOM))
> +		riscv_noncoherent_supported();

hmm, this changes the behaviour slightly. In the probe function there
is the
	if (!IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM))
		return false;
at the top, so with this change the second WARN_TAINT in arch_setup_dma_ops
will behave differently

Heiko