[RFC] ARM: EXYNOS: reset KFC cores when cpu is up

[Krzysztof Kozlowski]

On 15.07.2015 10:36, Chanho Park wrote:
> The cpu booting of exynos5422 has been still broken since we discussed
> it in last year[1]. I found this resetting codes from odroid-xu3 kernel of
> hardkernel, it could help to boot 8 cores well. This patch need to have
> more test like STR and other SoC especially exynos5800 which is variant
> of exynos5422. If this patch is broken on exynos5800, I'll find another
> way to check exynos5422.
> 
> This patch is top of my previous exynos5422 cpu ordering patch[2] and
> need to enable CONFIG_EXYNOS5420_MCPM=y

1. Why the ordering patch is required? It seems unrelated...
2. I tried this already (as in vendor sources from
opensource.samsung.com) and it did not help on my Odroid. Are you sure
that this patch solely fixes the problem?

Best regards,
Krzysztof

> 
> [    0.047509] CPU0: update cpu_capacity 448
> [    0.047534] CPU0: thread -1, cpu 0, socket 1, mpidr 80000100
> [    0.047874] Setting up static identity map for 0x400082c0 -
> 0x40008318
> [    0.048340] ARM CCI driver probed
> [    0.048597] Exynos MCPM support installed
> [    0.065676] CPU1: update cpu_capacity 448
> [    0.065685] CPU1: thread -1, cpu 1, socket 1, mpidr 80000101
> [    0.070672] CPU2: update cpu_capacity 448
> [    0.070680] CPU2: thread -1, cpu 2, socket 1, mpidr 80000102
> [    0.075644] CPU3: update cpu_capacity 448
> [    0.075653] CPU3: thread -1, cpu 3, socket 1, mpidr 80000103
> [    0.080590] CPU4: update cpu_capacity 1535
> [    0.080600] CPU4: thread -1, cpu 0, socket 0, mpidr 80000000
> [    0.085591] CPU5: update cpu_capacity 1535
> [    0.085599] CPU5: thread -1, cpu 1, socket 0, mpidr 80000001
> [    0.090590] CPU6: update cpu_capacity 1535
> [    0.090598] CPU6: thread -1, cpu 2, socket 0, mpidr 80000002
> [    0.095585] CPU7: update cpu_capacity 1535
> [    0.095593] CPU7: thread -1, cpu 3, socket 0, mpidr 80000003
> [    0.095720] Brought up 8 CPUs
> 
> [1]:http://lists.infradead.org/pipermail/linux-arm-kernel/2015-June/350632.html
> [2]:https://patchwork.kernel.org/patch/6782891/
> 
> Cc: Joonyoung Shim <jy0922.shim at samsung.com>
> Cc: Chanwoo Choi <cw00.choi at samsung.com>
> Cc: Kevin Hilman <khilman at kernel.org>
> Cc: Heesub Shin <heesub.shin at samsung.com>
> Cc: Mauro Ribeiro <mauro.ribeiro at hardkernel.com>
> Cc: Abhilash Kesavan <a.kesavan at samsung.com>
> Cc: Przemyslaw Marczak <p.marczak at samsung.com>
> Cc: Marek Szyprowski <m.szyprowski at samsung.com>
> Cc: Krzysztof Kozlowski <k.kozlowski at samsung.com>
> Signed-off-by: Chanho Park <chanho61.park at samsung.com>
> Signed-off-by: Chanho Park <parkch98 at gmail.com>
> ---
>  arch/arm/mach-exynos/mcpm-exynos.c | 13 ++++++++++++-
>  arch/arm/mach-exynos/regs-pmu.h    |  6 ++++++
>  2 files changed, 18 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/mach-exynos/mcpm-exynos.c b/arch/arm/mach-exynos/mcpm-exynos.c
> index 9bdf547..a076dde 100644
> --- a/arch/arm/mach-exynos/mcpm-exynos.c
> +++ b/arch/arm/mach-exynos/mcpm-exynos.c
> @@ -70,7 +70,18 @@ static int exynos_cpu_powerup(unsigned int cpu, unsigned int cluster)
>  		cluster >= EXYNOS5420_NR_CLUSTERS)
>  		return -EINVAL;
> 
> -	exynos_cpu_power_up(cpunr);
> +	if (!exynos_cpu_power_state(cpunr)) {
> +		exynos_cpu_power_up(cpunr);
> +
> +		if (soc_is_exynos5800() && cluster) {
> +			while (!pmu_raw_readl(S5P_PMU_SPARE2))
> +				udelay(10);
> +
> +			pmu_raw_writel(EXYNOS5420_KFC_CORE_RESET(cpu),
> +					EXYNOS_SWRESET);
> +		}
> +	}
> +
>  	return 0;
>  }
>  
> diff --git a/arch/arm/mach-exynos/regs-pmu.h b/arch/arm/mach-exynos/regs-pmu.h
> index b761433..fba9068 100644
> --- a/arch/arm/mach-exynos/regs-pmu.h
> +++ b/arch/arm/mach-exynos/regs-pmu.h
> @@ -513,6 +513,12 @@ static inline unsigned int exynos_pmu_cpunr(unsigned int mpidr)
>  #define SPREAD_ENABLE						0xF
>  #define SPREAD_USE_STANDWFI					0xF
>  
> +#define EXYNOS5420_KFC_CORE_RESET0				BIT(8)
> +#define EXYNOS5420_KFC_ETM_RESET0				BIT(20)
> +
> +#define EXYNOS5420_KFC_CORE_RESET(_nr)				\
> +	((EXYNOS5420_KFC_CORE_RESET0 | EXYNOS5420_KFC_ETM_RESET0) << (_nr))
> +
>  #define EXYNOS5420_BB_CON1					0x0784
>  #define EXYNOS5420_BB_SEL_EN					BIT(31)
>  #define EXYNOS5420_BB_PMOS_EN					BIT(7)
>