Re: [PATCH v9 09/12] ARM: EXYNOS: introduce exynos_cpu_info struct

[Krzysztof Kozlowski <krzk@kernel.org>]

On Thu, Mar 30, 2017 at 3:17 PM, Pankaj Dubey <pankaj.dubey@samsung.com> wrote:
> Various Exynos SoC has different CPU related information, such as CPU
> boot register, programming sequence making CPU up/down. Currently this
> is handled by adding lots of soc_is_exynosMMM checks in the code, in
> an attempt to remove the dependency of such helper functions specific to
> each SoC, let's separate this information pertaining to CPU by introducing
> a new "struct exynos_cpu_info". This struct will contain differences
> associated with CPU on various Exynos SoC. This can be matched by using
> generic API "soc_device_match".
>
> Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
> ---
>  arch/arm/mach-exynos/platsmp.c | 146 +++++++++++++++++++++++++++++++++++++----
>  1 file changed, 135 insertions(+), 11 deletions(-)
>
> diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c
> index cb6d199..ff369b9 100644
> --- a/arch/arm/mach-exynos/platsmp.c
> +++ b/arch/arm/mach-exynos/platsmp.c
> @@ -19,6 +19,7 @@
>  #include <linux/smp.h>
>  #include <linux/io.h>
>  #include <linux/of_address.h>
> +#include <linux/sys_soc.h>
>  #include <linux/soc/samsung/exynos-regs-pmu.h>
>
>  #include <asm/cacheflush.h>
> @@ -33,6 +34,16 @@
>
>  extern void exynos4_secondary_startup(void);
>
> +/*
> + * struct exynos_cpu_info - Exynos CPU related info/operations
> + * @cpu_boot_reg: computes cpu boot address for requested cpu
> + */
> +struct exynos_cpu_info {
> +       void __iomem* (*cpu_boot_reg)(u32 cpu);
> +};

Beside Marek comments, I think we are getting too many structures for
differentiating Exynos. Actually all of them describe the same -
difference between Exynos revisions. Having many separate structures
means that you have to initialize all of them in different places in
different (probably) order. The good benefit is however making them
local (static) so the scope is limited... but anyway I dislike the
duplication.

How about combining all of them into one (except the firmware which
has its own register function):

struct exynos_revision_data {
void __iomem* (*boot_vector_addr)(void);
void __iomem* (*boot_vector_flag)(void);
void (*enter_aftr)(void);
void __iomem* (*cpu_boot_reg)(u32 cpu);
void (*cpu_power_down)(u32 cpu);
void (*cpu_power_up)(u32 cpu);
};

Best regards,
Krzysztof


> +
> +static const struct exynos_cpu_info *cpu_info;
> +
>  #ifdef CONFIG_HOTPLUG_CPU
>  static inline void cpu_leave_lowpower(u32 core_id)
>  {
> @@ -168,27 +179,57 @@ int exynos_cluster_power_state(int cluster)
>                 S5P_CORE_LOCAL_PWR_EN);
>  }
>
> -static void __iomem *cpu_boot_reg_base(void)
> +static void __iomem *exynos4210_rev11_cpu_boot_reg(u32 cpu)
>  {
> -       if (soc_is_exynos4210() && samsung_rev() == EXYNOS4210_REV_1_1)
> -               return pmu_base_addr + S5P_INFORM5;
> -       return sysram_base_addr;
> +       void __iomem *boot_reg = pmu_base_addr;
> +
> +       if (!boot_reg)
> +               return IOMEM_ERR_PTR(-ENODEV);
> +
> +       boot_reg += S5P_INFORM5;
> +
> +       return boot_reg;
>  }
>
> -static inline void __iomem *cpu_boot_reg(int cpu)
> +static void __iomem *exynos4412_cpu_boot_reg(u32 cpu)
>  {
> -       void __iomem *boot_reg;
> +       void __iomem *boot_reg = sysram_base_addr;
>
> -       boot_reg = cpu_boot_reg_base();
>         if (!boot_reg)
>                 return IOMEM_ERR_PTR(-ENODEV);
> -       if (soc_is_exynos4412())
> -               boot_reg += 4*cpu;
> -       else if (soc_is_exynos5420() || soc_is_exynos5800())
> -               boot_reg += 4;
> +
> +       boot_reg += 4*cpu;
> +
>         return boot_reg;
>  }
>
> +static void __iomem *exynos5420_cpu_boot_reg(u32 cpu)
> +{
> +       void __iomem *boot_reg = sysram_base_addr;
> +
> +       if (!sysram_base_addr)
> +               return IOMEM_ERR_PTR(-ENODEV);
> +
> +       boot_reg += 4;
> +
> +       return boot_reg;
> +}
> +
> +static void __iomem *exynos_common_cpu_boot_reg(u32 cpu)
> +{
> +       if (!sysram_base_addr)
> +               return IOMEM_ERR_PTR(-ENODEV);
> +
> +       return sysram_base_addr;
> +}
> +
> +static inline void __iomem *cpu_boot_reg(int cpu)
> +{
> +       if (cpu_info && cpu_info->cpu_boot_reg)
> +               return cpu_info->cpu_boot_reg(cpu);
> +       return NULL;
> +}
> +
>  /*
>   * Set wake up by local power mode and execute software reset for given core.
>   *
> @@ -296,13 +337,84 @@ int exynos_get_boot_addr(u32 core_id, unsigned long *boot_addr)
>         return ret;
>  }
>
> +static const struct exynos_cpu_info exynos3250_cpu_info = {
> +       .cpu_boot_reg = exynos_common_cpu_boot_reg,
> +};
> +
> +static const struct exynos_cpu_info exynos5420_cpu_info = {
> +       .cpu_boot_reg = exynos5420_cpu_boot_reg,
> +};
> +
> +static const struct exynos_cpu_info exynos4210_rev11_cpu_info = {
> +       .cpu_boot_reg = exynos4210_rev11_cpu_boot_reg,
> +};
> +
> +static const struct exynos_cpu_info exynos4412_cpu_info = {
> +       .cpu_boot_reg = exynos4412_cpu_boot_reg,
> +};
> +
> +static const struct exynos_cpu_info exynos_common_cpu_info = {
> +       .cpu_boot_reg = exynos_common_cpu_boot_reg,
> +};
> +
> +static const struct soc_device_attribute exynos_soc_revision[] = {
> +       {
> +               .soc_id = "EXYNOS4210",
> +               .revision = "11",
> +               .data = &exynos4210_rev11_cpu_info
> +       }, {
> +               .soc_id = "EXYNOS4210",
> +               .revision = "10",
> +               .data = &exynos_common_cpu_info
> +       }
> +};
> +
> +static const struct of_device_id exynos_pmu_of_device_ids[] __initconst = {
> +       {
> +               .compatible = "samsung,exynos3250",
> +               .data = &exynos3250_cpu_info
> +       }, {
> +               .compatible = "samsung,exynos4212",
> +               .data = &exynos_common_cpu_info
> +       }, {
> +               .compatible = "samsung,exynos4412",
> +               .data = &exynos4412_cpu_info
> +       }, {
> +               .compatible = "samsung,exynos5250",
> +               .data = &exynos_common_cpu_info
> +       }, {
> +               .compatible = "samsung,exynos5260",
> +               .data = &exynos_common_cpu_info
> +       }, {
> +               .compatible = "samsung,exynos5410",
> +               .data = &exynos_common_cpu_info
> +       }, {
> +               .compatible = "samsung,exynos5420",
> +               .data = &exynos5420_cpu_info
> +       }, {
> +               .compatible = "samsung,exynos5440",
> +               .data = &exynos_common_cpu_info
> +       }, {
> +               .compatible = "samsung,exynos5800",
> +               .data = &exynos5420_cpu_info
> +       },
> +       { /*sentinel*/ },
> +};
> +
>  static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
>  {
>         unsigned long timeout;
> +       const struct soc_device_attribute *match;
>         u32 mpidr = cpu_logical_map(cpu);
>         u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
>         int ret = -ENOSYS;
>
> +       if (of_machine_is_compatible("samsung,exynos4210")) {
> +               match = soc_device_match(exynos_soc_revision);
> +               if (match)
> +                       cpu_info = (const struct exynos_cpu_info *) match->data;
> +       }
> +
>         /*
>          * Set synchronisation state between this boot processor
>          * and the secondary one
> @@ -387,6 +499,18 @@ static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
>
>  static void __init exynos_smp_prepare_cpus(unsigned int max_cpus)
>  {
> +       const struct of_device_id *match;
> +       struct device_node *np;
> +
> +       if (!of_machine_is_compatible("samsung,exynos4210")) {
> +               np = of_find_matching_node_and_match(NULL,
> +                               exynos_pmu_of_device_ids, &match);
> +               if (!np)
> +                       pr_err("failed to find supported CPU\n");
> +               else
> +                       cpu_info = (const struct exynos_cpu_info *) match->data;
> +       }
> +
>         exynos_sysram_init();
>
>         exynos_set_delayed_reset_assertion(true);
> --
> 2.7.4
>