Re: [PATCH V3 13/20] RISC-V: cpu: Enable cpuinfo for ACPI systems

[Conor Dooley]

On Fri, Mar 03, 2023 at 07:06:40PM +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@xxxxxxxxxxxxxxxx>
> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> ---
>  arch/riscv/kernel/cpu.c | 27 +++++++++++++++++++--------
>  1 file changed, 19 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index 8400f0cc9704..80101bf77dab 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>
> @@ -283,23 +285,32 @@ static void c_stop(struct seq_file *m, void *v)
>  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);
> -	print_mmu(m);
> -	if (!of_property_read_string(node, "compatible", &compat)
> -	    && strcmp(compat, "riscv"))
> -		seq_printf(m, "uarch\t\t: %s\n", compat);
> +
> +	if (acpi_disabled) {
> +		node = of_get_cpu_node(cpu_id, NULL);
> +		if (!of_property_read_string(node, "riscv,isa", &isa))
> +			print_isa(m, isa);
> +		print_mmu(m);
> +		if (!of_property_read_string(node, "compatible", &compat) &&
> +		    strcmp(compat, "riscv"))
> +			seq_printf(m, "uarch\t\t: %s\n", compat);
> +		of_node_put(node);

While you're touching this stuff, would you mind decorating it with some
whitespace between if statements?

> +	} else {
> +		if (!acpi_get_riscv_isa(NULL, get_acpi_id_for_cpu(cpu_id), &isa))
> +			print_isa(m, isa);
> +		print_mmu(m);

I assume ACPI has no equivalent of the compatible from which to generate
uarch?
A note as to why this is not present in the commit message would likely
be helpful to us ACPI-heathens.

> +	}
> +
>  	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
>

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