Re: [PATCH v8 4/8] ARM: EXYNOS: refactor firmware specific routines

[Krzysztof Kozlowski <krzk@kernel.org>]

On Sat, Dec 10, 2016 at 06:38:39PM +0530, Pankaj Dubey wrote:
> To remove dependency on soc_is_exynosMMMM macros and remove multiple
> checks for such macros lets refactor code in firmware.c file.
> SoC specific firmware_ops are separated and registered during
> exynos_firmware_init based on matching machine compatible.
> 
> Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
> ---
>  arch/arm/mach-exynos/firmware.c | 100 ++++++++++++++++++++++++++++++----------
>  1 file changed, 75 insertions(+), 25 deletions(-)
> 
> diff --git a/arch/arm/mach-exynos/firmware.c b/arch/arm/mach-exynos/firmware.c
> index fd6da54..525fbd9 100644
> --- a/arch/arm/mach-exynos/firmware.c
> +++ b/arch/arm/mach-exynos/firmware.c
> @@ -35,6 +35,25 @@ static void exynos_save_cp15(void)
>  	     : : "cc");
>  }
>  
> +static int exynos3250_do_idle(unsigned long mode)
> +{
> +	switch (mode) {
> +	case FW_DO_IDLE_AFTR:
> +		writel_relaxed(virt_to_phys(exynos_cpu_resume_ns),
> +			       sysram_ns_base_addr + 0x24);
> +		writel_relaxed(EXYNOS_AFTR_MAGIC, sysram_ns_base_addr + 0x20);
> +		flush_cache_all();
> +		exynos_smc(SMC_CMD_SAVE, OP_TYPE_CORE,
> +				SMC_POWERSTATE_IDLE, 0);
> +		exynos_smc(SMC_CMD_SHUTDOWN, OP_TYPE_CLUSTER,
> +				SMC_POWERSTATE_IDLE, 0);
> +		break;
> +	case FW_DO_IDLE_SLEEP:
> +		exynos_smc(SMC_CMD_SLEEP, 0, 0, 0);
> +	}
> +	return 0;
> +}
> +
>  static int exynos_do_idle(unsigned long mode)
>  {
>  	switch (mode) {
> @@ -44,14 +63,7 @@ static int exynos_do_idle(unsigned long mode)
>  		writel_relaxed(virt_to_phys(exynos_cpu_resume_ns),
>  			       sysram_ns_base_addr + 0x24);
>  		writel_relaxed(EXYNOS_AFTR_MAGIC, sysram_ns_base_addr + 0x20);
> -		if (soc_is_exynos3250()) {
> -			flush_cache_all();
> -			exynos_smc(SMC_CMD_SAVE, OP_TYPE_CORE,
> -				   SMC_POWERSTATE_IDLE, 0);
> -			exynos_smc(SMC_CMD_SHUTDOWN, OP_TYPE_CLUSTER,
> -				   SMC_POWERSTATE_IDLE, 0);
> -		} else
> -			exynos_smc(SMC_CMD_CPU0AFTR, 0, 0, 0);
> +		exynos_smc(SMC_CMD_CPU0AFTR, 0, 0, 0);
>  		break;
>  	case FW_DO_IDLE_SLEEP:
>  		exynos_smc(SMC_CMD_SLEEP, 0, 0, 0);
> @@ -59,28 +71,25 @@ static int exynos_do_idle(unsigned long mode)
>  	return 0;
>  }
>  
> -static int exynos_cpu_boot(int cpu)
> +static int exynos4412_cpu_boot(int cpu)
>  {
>  	/*
> -	 * Exynos3250 doesn't need to send smc command for secondary CPU boot
> -	 * because Exynos3250 removes WFE in secure mode.
> -	 */
> -	if (soc_is_exynos3250())
> -		return 0;
> -
> -	/*
>  	 * The second parameter of SMC_CMD_CPU1BOOT command means CPU id.
>  	 * But, Exynos4212 has only one secondary CPU so second parameter
>  	 * isn't used for informing secure firmware about CPU id.
>  	 */
> -	if (soc_is_exynos4212())
> -		cpu = 0;
> +	cpu = 0;

Why are you clearing the cpu for Exynos4412? Was it tested on
Exynos4412?

> +	exynos_smc(SMC_CMD_CPU1BOOT, cpu, 0, 0);
> +	return 0;
> +}
>  
> +static int exynos_cpu_boot(int cpu)
> +{
>  	exynos_smc(SMC_CMD_CPU1BOOT, cpu, 0, 0);

This will be executed on Exynos4212...

>  	return 0;
>  }
>  
> -static int exynos_set_cpu_boot_addr(int cpu, unsigned long boot_addr)
> +static int exynos4412_set_cpu_boot_addr(int cpu, unsigned long boot_addr)
>  {
>  	void __iomem *boot_reg;
>  
> @@ -94,14 +103,24 @@ static int exynos_set_cpu_boot_addr(int cpu, unsigned long boot_addr)
>  	 * additional offset for every CPU, with Exynos4412 being the only
>  	 * exception.
>  	 */
> -	if (soc_is_exynos4412())
> -		boot_reg += 4 * cpu;
> +	boot_reg += 4 * cpu;
> +	writel_relaxed(boot_addr, boot_reg);
> +	return 0;
> +}
> +
> +static int exynos_set_cpu_boot_addr(int cpu, unsigned long boot_addr)
> +{
> +	void __iomem *boot_reg;
>  
> +	if (!sysram_ns_base_addr)
> +		return -ENODEV;
> +
> +	boot_reg = sysram_ns_base_addr + 0x1c;
>  	writel_relaxed(boot_addr, boot_reg);
>  	return 0;
>  }
>  
> -static int exynos_get_cpu_boot_addr(int cpu, unsigned long *boot_addr)
> +static int exynos4412_get_cpu_boot_addr(int cpu, unsigned long *boot_addr)
>  {
>  	void __iomem *boot_reg;
>  
> @@ -109,10 +128,19 @@ static int exynos_get_cpu_boot_addr(int cpu, unsigned long *boot_addr)
>  		return -ENODEV;
>  
>  	boot_reg = sysram_ns_base_addr + 0x1c;
> +	boot_reg += 4 * cpu;
> +	*boot_addr = readl_relaxed(boot_reg);
> +	return 0;
> +}
> +
> +static int exynos_get_cpu_boot_addr(int cpu, unsigned long *boot_addr)
> +{
> +	void __iomem *boot_reg;
>  
> -	if (soc_is_exynos4412())
> -		boot_reg += 4 * cpu;
> +	if (!sysram_ns_base_addr)
> +		return -ENODEV;
>  
> +	boot_reg = sysram_ns_base_addr + 0x1c;
>  	*boot_addr = readl_relaxed(boot_reg);
>  	return 0;
>  }
> @@ -148,6 +176,23 @@ static int exynos_resume(void)
>  	return 0;
>  }
>  
> +static const struct firmware_ops exynos3250_firmware_ops = {
> +	.do_idle		= IS_ENABLED(CONFIG_EXYNOS_CPU_SUSPEND) ? exynos3250_do_idle : NULL,
> +	.set_cpu_boot_addr	= exynos_set_cpu_boot_addr,
> +	.get_cpu_boot_addr	= exynos_get_cpu_boot_addr,

You know that lack of cpu_boot() is not equivalent to previous
'return 0' code? Now -ENOSYS will be returned... which is not a problem
because return values for cpu_boot are ignored... just wondering whether
this was planned.

> +	.suspend		= IS_ENABLED(CONFIG_PM_SLEEP) ? exynos_suspend : NULL,
> +	.resume			= IS_ENABLED(CONFIG_EXYNOS_CPU_SUSPEND) ? exynos_resume : NULL,
> +};
> +
> +static const struct firmware_ops exynos4412_firmware_ops = {
> +	.do_idle		= IS_ENABLED(CONFIG_EXYNOS_CPU_SUSPEND) ? exynos_do_idle : NULL,
> +	.set_cpu_boot_addr	= exynos4412_set_cpu_boot_addr,
> +	.get_cpu_boot_addr	= exynos4412_get_cpu_boot_addr,
> +	.cpu_boot		= exynos4412_cpu_boot,
> +	.suspend		= IS_ENABLED(CONFIG_PM_SLEEP) ? exynos_suspend : NULL,
> +	.resume			= IS_ENABLED(CONFIG_EXYNOS_CPU_SUSPEND) ? exynos_resume : NULL,
> +};
> +
>  static const struct firmware_ops exynos_firmware_ops = {
>  	.do_idle		= IS_ENABLED(CONFIG_EXYNOS_CPU_SUSPEND) ? exynos_do_idle : NULL,
>  	.set_cpu_boot_addr	= exynos_set_cpu_boot_addr,
> @@ -212,7 +257,12 @@ void __init exynos_firmware_init(void)
>  
>  	pr_info("Running under secure firmware.\n");
>  
> -	register_firmware_ops(&exynos_firmware_ops);
> +	if (of_machine_is_compatible("samsung,exynos3250"))
> +		register_firmware_ops(&exynos3250_firmware_ops);
> +	else if (of_machine_is_compatible("samsung,exynos4412"))
> +		register_firmware_ops(&exynos4412_firmware_ops);
> +	else
> +		register_firmware_ops(&exynos_firmware_ops);

I prefer one register_firmware_ops() call, so something like:
	const struct firmware_ops *ops;
	if (...)
		ops = &exynos3250_firmware_ops;
	else if ()
		...
	register_firmware_ops(ops);

It is a matter of taste but for me it is more common pattern, looks more
readable and it reduces number of callers to register_firmware_ops() (so
it is easier to find them).

Krzysztof
>  
>  	/*
>  	 * Exynos 4 SoCs (based on Cortex A9 and equipped with L2C-310),
> -- 
> 2.7.4
>