Re: [PATCH V2 13/21] RISC-V: cpu: Enable cpuinfo for ACPI systems

From: Andrew Jones <ajones@ventanamicro.com>
To: Sunil V L <sunilvl@ventanamicro.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	Len Brown <lenb@kernel.org>, Thomas Gleixner <tglx@linutronix.de>,
	Marc Zyngier <maz@kernel.org>, Jonathan Corbet <corbet@lwn.net>,
	linux-riscv@lists.infradead.org, linux-acpi@vger.kernel.org,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	Conor Dooley <conor.dooley@microchip.com>,
	Anup Patel <apatel@ventanamicro.com>,
	Atish Patra <atishp@rivosinc.com>,
	"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Subject: Re: [PATCH V2 13/21] RISC-V: cpu: Enable cpuinfo for ACPI systems
Date: Mon, 20 Feb 2023 18:54:29 +0100	[thread overview]
Message-ID: <20230220175429.dzojoryw2dhhbodl@orel> (raw)
In-Reply-To: <20230216182043.1946553-14-sunilvl@ventanamicro.com>

On Thu, Feb 16, 2023 at 11:50:35PM +0530, Sunil V L wrote:
> On ACPI based platforms, few details like ISA need to be read
> from the ACPI table. Enable cpuinfo on ACPI based systems.
> 
> Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
>  arch/riscv/kernel/cpu.c | 31 ++++++++++++++++++++++++-------
>  1 file changed, 24 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index 1b9a5a66e55a..a227c0661b19 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -3,10 +3,12 @@
>   * Copyright (C) 2012 Regents of the University of California
>   */
>  
> +#include <linux/acpi.h>
>  #include <linux/cpu.h>
>  #include <linux/init.h>
>  #include <linux/seq_file.h>
>  #include <linux/of.h>
> +#include <asm/acpi.h>
>  #include <asm/csr.h>
>  #include <asm/hwcap.h>
>  #include <asm/sbi.h>
> @@ -256,26 +258,41 @@ static void c_stop(struct seq_file *m, void *v)
>  {
>  }
>  
> +static void acpi_print_hart_info(struct seq_file *m, unsigned long cpu)
> +{
> +	const char *isa;
> +
> +	if (!acpi_get_riscv_isa(NULL, get_acpi_id_for_cpu(cpu), &isa))
> +		print_isa(m, isa);
> +}
> +
>  static int c_show(struct seq_file *m, void *v)
>  {
>  	unsigned long cpu_id = (unsigned long)v - 1;
> -	struct device_node *node = of_get_cpu_node(cpu_id, NULL);
>  	struct riscv_cpuinfo *ci = per_cpu_ptr(&riscv_cpuinfo, cpu_id);
> +	struct device_node *node;
>  	const char *compat, *isa;
>  
>  	seq_printf(m, "processor\t: %lu\n", cpu_id);
>  	seq_printf(m, "hart\t\t: %lu\n", cpuid_to_hartid_map(cpu_id));
> -	if (!of_property_read_string(node, "riscv,isa", &isa))
> -		print_isa(m, isa);
> +
> +	if (acpi_disabled) {
> +		node = of_get_cpu_node(cpu_id, NULL);
> +		if (!of_property_read_string(node, "riscv,isa", &isa))
> +			print_isa(m, isa);
> +		if (!of_property_read_string(node, "compatible", &compat) &&
> +		    strcmp(compat, "riscv"))
> +			seq_printf(m, "uarch\t\t: %s\n", compat);
> +		of_node_put(node);
> +	} else {
> +		acpi_print_hart_info(m, cpu_id);

I don't think we need the helper function for the two lines which would
otherwise nicely complement the two similar DT lines above.

> +	}
> +
>  	print_mmu(m);
> -	if (!of_property_read_string(node, "compatible", &compat)
> -	    && strcmp(compat, "riscv"))
> -		seq_printf(m, "uarch\t\t: %s\n", compat);

This will now print uarch before mmu for DT systems.

>  	seq_printf(m, "mvendorid\t: 0x%lx\n", ci->mvendorid);
>  	seq_printf(m, "marchid\t\t: 0x%lx\n", ci->marchid);
>  	seq_printf(m, "mimpid\t\t: 0x%lx\n", ci->mimpid);
>  	seq_puts(m, "\n");
> -	of_node_put(node);
>  
>  	return 0;
>  }
> -- 
> 2.34.1
>

Thanks,
drew