RE: [PATCH 2/6] ARM: EXYNOS: Fix core ID used by platsmp and hotplug code

[Kukjin Kim]

Tomasz Figa wrote:
> 
> When CPU topology is specified in device tree, cpu_logical_map() does
> not return core ID anymore, but rather full MPIDR value. This breaks
> existing calculation of PMU register offsets on Exynos SoCs.
> 
> This patch fixes the problem by adjusting the code to use only core ID
> bits of the value returned by cpu_logical_map() to allow CPU topology to
> be specified in device tree on Exynos SoCs.
> 
> Signed-off-by: Tomasz Figa <t.figa@xxxxxxxxxxx>

Looks good to me, but I think we don't need this fix in 3.16 because the CPU
topology is not specified in DT yet...if I'm wrong, please correct me.

Will apply for 3.17.

Thanks,
Kukjin

> ---
>  arch/arm/mach-exynos/hotplug.c | 10 ++++++----
>  arch/arm/mach-exynos/platsmp.c | 34 +++++++++++++++++++---------------
>  2 files changed, 25 insertions(+), 19 deletions(-)
> 
> diff --git a/arch/arm/mach-exynos/hotplug.c b/arch/arm/mach-exynos/hotplug.c
> index 69fa483..5644dac 100644
> --- a/arch/arm/mach-exynos/hotplug.c
> +++ b/arch/arm/mach-exynos/hotplug.c
> @@ -40,11 +40,13 @@ static inline void cpu_leave_lowpower(void)
> 
>  static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
>  {
> +	u32 mpidr = cpu_logical_map(cpu);
> +	u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
> +
>  	for (;;) {
> 
> -		/* make cpu1 to be turned off at next WFI command */
> -		if (cpu == 1)
> -			exynos_cpu_power_down(cpu);
> +		/* Turn the CPU off on next WFI instruction. */
> +		exynos_cpu_power_down(core_id);
> 
>  		/*
>  		 * here's the WFI
> @@ -54,7 +56,7 @@ static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
>  		    :
>  		    : "memory", "cc");
> 
> -		if (pen_release == cpu_logical_map(cpu)) {
> +		if (pen_release == core_id) {
>  			/*
>  			 * OK, proper wakeup, we're done
>  			 */
> diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c
> index 1c8d31e..50b9aad 100644
> --- a/arch/arm/mach-exynos/platsmp.c
> +++ b/arch/arm/mach-exynos/platsmp.c
> @@ -90,7 +90,8 @@ static void exynos_secondary_init(unsigned int cpu)
>  static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
>  {
>  	unsigned long timeout;
> -	unsigned long phys_cpu = cpu_logical_map(cpu);
> +	u32 mpidr = cpu_logical_map(cpu);
> +	u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
>  	int ret = -ENOSYS;
> 
>  	/*
> @@ -104,17 +105,18 @@ static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
>  	 * the holding pen - release it, then wait for it to flag
>  	 * that it has been released by resetting pen_release.
>  	 *
> -	 * Note that "pen_release" is the hardware CPU ID, whereas
> +	 * Note that "pen_release" is the hardware CPU core ID, whereas
>  	 * "cpu" is Linux's internal ID.
>  	 */
> -	write_pen_release(phys_cpu);
> +	write_pen_release(core_id);
> 
> -	if (!exynos_cpu_power_state(cpu)) {
> -		exynos_cpu_power_up(cpu);
> +	if (!exynos_cpu_power_state(core_id)) {
> +		exynos_cpu_power_up(core_id);
>  		timeout = 10;
> 
>  		/* wait max 10 ms until cpu1 is on */
> -		while (exynos_cpu_power_state(cpu) != S5P_CORE_LOCAL_PWR_EN) {
> +		while (exynos_cpu_power_state(core_id)
> +		       != S5P_CORE_LOCAL_PWR_EN) {
>  			if (timeout-- == 0)
>  				break;
> 
> @@ -145,20 +147,20 @@ static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
>  		 * Try to set boot address using firmware first
>  		 * and fall back to boot register if it fails.
>  		 */
> -		ret = call_firmware_op(set_cpu_boot_addr, phys_cpu, boot_addr);
> +		ret = call_firmware_op(set_cpu_boot_addr, core_id, boot_addr);
>  		if (ret && ret != -ENOSYS)
>  			goto fail;
>  		if (ret == -ENOSYS) {
> -			void __iomem *boot_reg = cpu_boot_reg(phys_cpu);
> +			void __iomem *boot_reg = cpu_boot_reg(core_id);
> 
>  			if (IS_ERR(boot_reg)) {
>  				ret = PTR_ERR(boot_reg);
>  				goto fail;
>  			}
> -			__raw_writel(boot_addr, cpu_boot_reg(phys_cpu));
> +			__raw_writel(boot_addr, cpu_boot_reg(core_id));
>  		}
> 
> -		call_firmware_op(cpu_boot, phys_cpu);
> +		call_firmware_op(cpu_boot, core_id);
> 
>  		arch_send_wakeup_ipi_mask(cpumask_of(cpu));
> 
> @@ -227,22 +229,24 @@ static void __init exynos_smp_prepare_cpus(unsigned int max_cpus)
>  	 * boot register if it fails.
>  	 */
>  	for (i = 1; i < max_cpus; ++i) {
> -		unsigned long phys_cpu;
>  		unsigned long boot_addr;
> +		u32 mpidr;
> +		u32 core_id;
>  		int ret;
> 
> -		phys_cpu = cpu_logical_map(i);
> +		mpidr = cpu_logical_map(i);
> +		core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
>  		boot_addr = virt_to_phys(exynos4_secondary_startup);
> 
> -		ret = call_firmware_op(set_cpu_boot_addr, phys_cpu, boot_addr);
> +		ret = call_firmware_op(set_cpu_boot_addr, core_id, boot_addr);
>  		if (ret && ret != -ENOSYS)
>  			break;
>  		if (ret == -ENOSYS) {
> -			void __iomem *boot_reg = cpu_boot_reg(phys_cpu);
> +			void __iomem *boot_reg = cpu_boot_reg(core_id);
> 
>  			if (IS_ERR(boot_reg))
>  				break;
> -			__raw_writel(boot_addr, cpu_boot_reg(phys_cpu));
> +			__raw_writel(boot_addr, cpu_boot_reg(core_id));
>  		}
>  	}
>  }
> --
> 1.9.3

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