Re: [Xen-devel] [PATCH 1/2] xen/arm: Initial support for PSCI-0.2

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

On Wed, 1 Oct 2014, suravee.suthikulpanit@xxxxxxx wrote:
> From: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
> 
> This patch adds support for PSCI-0.2 PSCI_VERSION, CPU_ON,
> SYSTEM_OFF, and SYSTEM_RESET functions.
> 
> For PSCI-0.2, the new DT binding "arm,psci-0.2" is used for matching.
> The psci_init() is now refactored to handle both PSCI-0.1 and PSCI-0.2.
> 
> Also, to add support for PSCI_VERSION, this patch replaces the "bool_t 
> psci_available"
> variable with "int psci_ver", which contains the PSCI_VERSION as described in 
> the
> PSCI-0.2 spec. For v0.1, this psci_ver is 1.
> 
> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>

The support to PSCI 0.2 added by this patch is a bit incomplete, but on
the other hand the patch is very simple so it might just be the only
thing we can actually accept for this release.

Acked-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>


>  xen/arch/arm/arm64/smpboot.c |  2 +-
>  xen/arch/arm/platform.c      |  2 +-
>  xen/arch/arm/psci.c          | 72 
> +++++++++++++++++++++++++++++++++++++++-----
>  xen/include/asm-arm/psci.h   |  4 ++-
>  4 files changed, 69 insertions(+), 11 deletions(-)
> 
> diff --git a/xen/arch/arm/arm64/smpboot.c b/xen/arch/arm/arm64/smpboot.c
> index 9146476..341cc77 100644
> --- a/xen/arch/arm/arm64/smpboot.c
> +++ b/xen/arch/arm/arm64/smpboot.c
> @@ -54,7 +54,7 @@ static void __init smp_spin_table_init(int cpu, struct 
> dt_device_node *dn)
>  
>  static int __init smp_psci_init(int cpu)
>  {
> -    if ( !psci_available )
> +    if ( !psci_ver )
>      {
>          printk("CPU%d asks for PSCI, but DTB has no PSCI node\n", cpu);
>          return -ENODEV;
> diff --git a/xen/arch/arm/platform.c b/xen/arch/arm/platform.c
> index 74c3328..cb4cda8 100644
> --- a/xen/arch/arm/platform.c
> +++ b/xen/arch/arm/platform.c
> @@ -110,7 +110,7 @@ int __init platform_specific_mapping(struct domain *d)
>  #ifdef CONFIG_ARM_32
>  int __init platform_cpu_up(int cpu)
>  {
> -    if ( psci_available )
> +    if ( psci_ver )
>          return call_psci_cpu_on(cpu);
>  
>      if ( platform && platform->cpu_up )
> diff --git a/xen/arch/arm/psci.c b/xen/arch/arm/psci.c
> index b6360d5..874917e 100644
> --- a/xen/arch/arm/psci.c
> +++ b/xen/arch/arm/psci.c
> @@ -23,7 +23,7 @@
>  #include <xen/smp.h>
>  #include <asm/psci.h>
>  
> -bool_t psci_available;
> +int psci_ver;
>  
>  #ifdef CONFIG_ARM_32
>  #define REG_PREFIX "r"
> @@ -58,16 +58,23 @@ int call_psci_cpu_on(int cpu)
>                                  cpu_logical_map(cpu), __pa(init_secondary), 
> 0);
>  }
>  
> -int __init psci_init(void)
> +void call_psci_system_off(void)
> +{
> +    if ( psci_ver > 2 )
> +        __invoke_psci_fn_smc(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
> +}
> +
> +void call_psci_system_reset(void)
> +{
> +    if ( psci_ver > 2 )
> +        __invoke_psci_fn_smc(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
> +}
> +
> +int __init psci_is_smc_method(const struct dt_device_node *psci)
>  {
> -    const struct dt_device_node *psci;
>      int ret;
>      const char *prop_str;
>  
> -    psci = dt_find_compatible_node(NULL, NULL, "arm,psci");
> -    if ( !psci )
> -        return -ENODEV;
> -
>      ret = dt_property_read_string(psci, "method", &prop_str);
>      if ( ret )
>      {
> @@ -85,19 +92,68 @@ int __init psci_init(void)
>          return -EINVAL;
>      }
>  
> +    return 0;
> +}
> +
> +int __init psci_init_0_1(const struct dt_device_node *psci)
> +{
> +    int ret;
> +
> +    ret = psci_is_smc_method(psci);
> +    if ( ret )
> +        return -EINVAL;
> +
>      if ( !dt_property_read_u32(psci, "cpu_on", &psci_cpu_on_nr) )
>      {
>          printk("/psci node is missing the \"cpu_on\" property\n");
>          return -ENOENT;
>      }
>  
> -    psci_available = 1;
> +    psci_ver = 1;
>  
>      printk(XENLOG_INFO "Using PSCI for SMP bringup\n");
>  
>      return 0;
>  }
>  
> +int __init psci_init_0_2(const struct dt_device_node *psci)
> +{
> +    int ret;
> +
> +    ret = psci_is_smc_method(psci);
> +    if ( ret )
> +        return -EINVAL;
> +
> +    psci_ver = __invoke_psci_fn_smc(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
> +
> +    if ( psci_ver != 2 )
> +    {
> +        printk("Error: The retrieved PSCI version (%#x) does not 
> support.\n", psci_ver);
> +        return -EOPNOTSUPP;
> +    }
> +
> +    psci_cpu_on_nr = PSCI_0_2_FN_CPU_ON;
> +
> +    printk(XENLOG_INFO "Using PSCI-0.2 for SMP bringup\n");
> +
> +    return 0;
> +}
> +
> +int __init psci_init(void)
> +{
> +    const struct dt_device_node *psci;
> +
> +    psci = dt_find_compatible_node(NULL, NULL, "arm,psci");
> +    if ( psci )
> +        return psci_init_0_1(psci);
> +
> +    psci = dt_find_compatible_node(NULL, NULL, "arm,psci-0.2");
> +    if ( psci )
> +        return psci_init_0_2(psci);
> +
> +    return -ENODEV;
> +}
> +
>  /*
>   * Local variables:
>   * mode: C
> diff --git a/xen/include/asm-arm/psci.h b/xen/include/asm-arm/psci.h
> index 9777c03..ab37984 100644
> --- a/xen/include/asm-arm/psci.h
> +++ b/xen/include/asm-arm/psci.h
> @@ -13,10 +13,12 @@
>  #define PSCI_DISABLED               -8
>  
>  /* availability of PSCI on the host for SMP bringup */
> -extern bool_t psci_available;
> +extern int psci_ver;
>  
>  int psci_init(void);
>  int call_psci_cpu_on(int cpu);
> +void call_psci_system_off(void);
> +void call_psci_system_reset(void);
>  
>  /* functions to handle guest PSCI requests */
>  int32_t do_psci_cpu_on(uint32_t vcpuid, register_t entry_point);
> -- 
> 1.9.3
> 

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