Re: [PATCH v2 -next 1/3] cpuidle: RISC-V: Move few functions to arch/riscv

[Andrew Jones]

On Mon, Jan 15, 2024 at 03:40:54PM +0530, Sunil V L wrote:
> To support ACPI Low Power Idle (LPI), few functions are required which
> are currently static functions in the DT based cpuidle driver. Hence,
> move them under arch/riscv so that ACPI driver also can use them.
> 
> Signed-off-by: Sunil V L <sunilvl@xxxxxxxxxxxxxxxx>
> ---
>  arch/riscv/include/asm/suspend.h    |  3 ++
>  arch/riscv/kernel/suspend.c         | 47 +++++++++++++++++++++++++++++
>  drivers/cpuidle/cpuidle-riscv-sbi.c | 41 +------------------------
>  3 files changed, 51 insertions(+), 40 deletions(-)
> 
> diff --git a/arch/riscv/include/asm/suspend.h b/arch/riscv/include/asm/suspend.h
> index 02f87867389a..5c7df5ab7a16 100644
> --- a/arch/riscv/include/asm/suspend.h
> +++ b/arch/riscv/include/asm/suspend.h
> @@ -55,4 +55,7 @@ int hibernate_resume_nonboot_cpu_disable(void);
>  asmlinkage void hibernate_restore_image(unsigned long resume_satp, unsigned long satp_temp,
>  					unsigned long cpu_resume);
>  asmlinkage int hibernate_core_restore_code(void);
> +bool is_sbi_hsm_supported(void);
> +bool sbi_suspend_state_is_valid(u32 state);
> +int sbi_suspend(u32 state);
>  #endif
> diff --git a/arch/riscv/kernel/suspend.c b/arch/riscv/kernel/suspend.c
> index 239509367e42..a3b2e7e16a98 100644
> --- a/arch/riscv/kernel/suspend.c
> +++ b/arch/riscv/kernel/suspend.c
> @@ -128,4 +128,51 @@ static int __init sbi_system_suspend_init(void)
>  }
>  
>  arch_initcall(sbi_system_suspend_init);
> +
> +static int sbi_suspend_finisher(unsigned long suspend_type,
> +				unsigned long resume_addr,
> +				unsigned long opaque)
> +{
> +	struct sbiret ret;
> +
> +	ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_SUSPEND,
> +			suspend_type, resume_addr, opaque, 0, 0, 0);
> +
> +	return (ret.error) ? sbi_err_map_linux_errno(ret.error) : 0;
> +}
> +
> +int sbi_suspend(u32 state)

Now that this is exported, I'd name it riscv_sbi_suspend.

> +{
> +	if (state & SBI_HSM_SUSP_NON_RET_BIT)
> +		return cpu_suspend(state, sbi_suspend_finisher);
> +	else
> +		return sbi_suspend_finisher(state, 0, 0);
> +}
> +
> +bool sbi_suspend_state_is_valid(u32 state)

Also riscv_ prefix here.

> +{
> +	if (state > SBI_HSM_SUSPEND_RET_DEFAULT &&
> +	    state < SBI_HSM_SUSPEND_RET_PLATFORM)
> +		return false;
> +	if (state > SBI_HSM_SUSPEND_NON_RET_DEFAULT &&
> +	    state < SBI_HSM_SUSPEND_NON_RET_PLATFORM)
> +		return false;
> +	return true;
> +}
> +
> +bool is_sbi_hsm_supported(void)

This I would rename to riscv_sbi_hsm_is_supported

> +{
> +	/*
> +	 * The SBI HSM suspend function is only available when:
> +	 * 1) SBI version is 0.3 or higher
> +	 * 2) SBI HSM extension is available
> +	 */
> +	if (sbi_spec_version < sbi_mk_version(0, 3) ||
> +	    !sbi_probe_extension(SBI_EXT_HSM)) {
> +		pr_info("HSM suspend not available\n");
> +		return false;
> +	}
> +
> +	return true;
> +}
>  #endif /* CONFIG_RISCV_SBI */
> diff --git a/drivers/cpuidle/cpuidle-riscv-sbi.c b/drivers/cpuidle/cpuidle-riscv-sbi.c
> index e8094fc92491..a7f06242f67b 100644
> --- a/drivers/cpuidle/cpuidle-riscv-sbi.c
> +++ b/drivers/cpuidle/cpuidle-riscv-sbi.c
> @@ -73,26 +73,6 @@ static inline bool sbi_is_domain_state_available(void)
>  	return data->available;
>  }
>  
> -static int sbi_suspend_finisher(unsigned long suspend_type,
> -				unsigned long resume_addr,
> -				unsigned long opaque)
> -{
> -	struct sbiret ret;
> -
> -	ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_SUSPEND,
> -			suspend_type, resume_addr, opaque, 0, 0, 0);
> -
> -	return (ret.error) ? sbi_err_map_linux_errno(ret.error) : 0;
> -}
> -
> -static int sbi_suspend(u32 state)
> -{
> -	if (state & SBI_HSM_SUSP_NON_RET_BIT)
> -		return cpu_suspend(state, sbi_suspend_finisher);
> -	else
> -		return sbi_suspend_finisher(state, 0, 0);
> -}
> -
>  static __cpuidle int sbi_cpuidle_enter_state(struct cpuidle_device *dev,
>  					     struct cpuidle_driver *drv, int idx)
>  {
> @@ -206,17 +186,6 @@ static const struct of_device_id sbi_cpuidle_state_match[] = {
>  	{ },
>  };
>  
> -static bool sbi_suspend_state_is_valid(u32 state)
> -{
> -	if (state > SBI_HSM_SUSPEND_RET_DEFAULT &&
> -	    state < SBI_HSM_SUSPEND_RET_PLATFORM)
> -		return false;
> -	if (state > SBI_HSM_SUSPEND_NON_RET_DEFAULT &&
> -	    state < SBI_HSM_SUSPEND_NON_RET_PLATFORM)
> -		return false;
> -	return true;
> -}
> -
>  static int sbi_dt_parse_state_node(struct device_node *np, u32 *state)
>  {
>  	int err = of_property_read_u32(np, "riscv,sbi-suspend-param", state);
> @@ -607,16 +576,8 @@ static int __init sbi_cpuidle_init(void)
>  	int ret;
>  	struct platform_device *pdev;
>  
> -	/*
> -	 * The SBI HSM suspend function is only available when:
> -	 * 1) SBI version is 0.3 or higher
> -	 * 2) SBI HSM extension is available
> -	 */
> -	if ((sbi_spec_version < sbi_mk_version(0, 3)) ||
> -	    !sbi_probe_extension(SBI_EXT_HSM)) {
> -		pr_info("HSM suspend not available\n");
> +	if (!is_sbi_hsm_supported())
>  		return 0;
> -	}
>  
>  	ret = platform_driver_register(&sbi_cpuidle_driver);
>  	if (ret)
> -- 
> 2.34.1
>

Otherwise,

Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>