Re: [PATCH v4 09/21] arm/acpi: Add ACPI support for SMP initialization

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

On Sat, 23 Jan 2016, Shannon Zhao wrote:
> From: Shannon Zhao <shannon.zhao@linaro.org>
> 
> ACPI 5.1 only has two explicit methods to boot up SMP, PSCI and Parking
> protocol, but the Parking protocol is only specified for ARMv7 now, so
> make PSCI as the only way for the SMP boot protocol before some updates
> for the ACPI spec or the Parking protocol spec.
> 
> ACPI only supports PSCI 0.2+, since prior to PSCI 0.2 function IDs are
> not well-defined.
> 
> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
> Signed-off-by: Parth Dixit <parth.dixit@linaro.org>
> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>

Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>


> V4: explain why only support PSCI 0.2+ and print an error message for
>     PSCI 0.1 and SMC not present
> ---
> 
>  xen/arch/arm/arm64/smpboot.c |  7 ++++++-
>  xen/arch/arm/psci.c          | 35 ++++++++++++++++++++++++++++-------
>  xen/arch/arm/smpboot.c       |  7 ++++++-
>  3 files changed, 40 insertions(+), 9 deletions(-)
> 
> diff --git a/xen/arch/arm/arm64/smpboot.c b/xen/arch/arm/arm64/smpboot.c
> index 7928f69..4fd0ac6 100644
> --- a/xen/arch/arm/arm64/smpboot.c
> +++ b/xen/arch/arm/arm64/smpboot.c
> @@ -7,6 +7,7 @@
>  #include <xen/vmap.h>
>  #include <asm/io.h>
>  #include <asm/psci.h>
> +#include <asm/acpi.h>
>  
>  struct smp_enable_ops {
>          int             (*prepare_cpu)(int);
> @@ -96,7 +97,11 @@ static int __init dt_arch_cpu_init(int cpu, struct dt_device_node *dn)
>  
>  int __init arch_cpu_init(int cpu, struct dt_device_node *dn)
>  {
> -    return dt_arch_cpu_init(cpu, dn);
> +    if ( acpi_disabled )
> +        return dt_arch_cpu_init(cpu, dn);
> +    else
> +        /* acpi only supports psci at present */
> +        return smp_psci_init(cpu);
>  }
>  
>  int __init arch_cpu_up(int cpu)
> diff --git a/xen/arch/arm/psci.c b/xen/arch/arm/psci.c
> index d800cb6..7966b5e 100644
> --- a/xen/arch/arm/psci.c
> +++ b/xen/arch/arm/psci.c
> @@ -22,6 +22,7 @@
>  #include <xen/mm.h>
>  #include <xen/smp.h>
>  #include <asm/psci.h>
> +#include <asm/acpi.h>
>  
>  /*
>   * While a 64-bit OS can make calls with SMC32 calling conventions, for
> @@ -86,6 +87,12 @@ int __init psci_init_0_1(void)
>      int ret;
>      const struct dt_device_node *psci;
>  
> +    if ( !acpi_disabled )
> +    {
> +        printk("PSCI 0.1 is not supported when using ACPI\n");
> +        return -EINVAL;
> +    }
> +
>      psci = dt_find_compatible_node(NULL, NULL, "arm,psci");
>      if ( !psci )
>          return -EOPNOTSUPP;
> @@ -116,15 +123,26 @@ int __init psci_init_0_2(void)
>          { /* sentinel */ },
>      };
>      int ret;
> -    const struct dt_device_node *psci;
>  
> -    psci = dt_find_matching_node(NULL, psci_ids);
> -    if ( !psci )
> -        return -EOPNOTSUPP;
> +    if ( acpi_disabled )
> +    {
> +        const struct dt_device_node *psci;
>  
> -    ret = psci_is_smc_method(psci);
> -    if ( ret )
> -        return -EINVAL;
> +        psci = dt_find_matching_node(NULL, psci_ids);
> +        if ( !psci )
> +            return -EOPNOTSUPP;
> +
> +        ret = psci_is_smc_method(psci);
> +        if ( ret )
> +            return -EINVAL;
> +    }
> +    else
> +    {
> +        if ( acpi_psci_hvc_present() ) {
> +            printk("PSCI conduit must be SMC, but is HVC\n");
> +            return -EINVAL;
> +        }
> +    }
>  
>      psci_ver = call_smc(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
>  
> @@ -148,6 +166,9 @@ int __init psci_init(void)
>  {
>      int ret;
>  
> +    if ( !acpi_disabled && !acpi_psci_present() )
> +        return -EOPNOTSUPP;
> +
>      ret = psci_init_0_2();
>      if ( ret )
>          ret = psci_init_0_1();
> diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c
> index b6119d1..c5109bf 100644
> --- a/xen/arch/arm/smpboot.c
> +++ b/xen/arch/arm/smpboot.c
> @@ -31,6 +31,7 @@
>  #include <xen/console.h>
>  #include <asm/gic.h>
>  #include <asm/psci.h>
> +#include <asm/acpi.h>
>  
>  cpumask_t cpu_online_map;
>  cpumask_t cpu_present_map;
> @@ -247,7 +248,11 @@ void __init smp_init_cpus(void)
>          return;
>      }
>  
> -    dt_smp_init_cpus();
> +    if ( acpi_disabled )
> +        dt_smp_init_cpus();
> +    else
> +        acpi_smp_init_cpus();
> +
>  }
>  
>  int __init
> -- 
> 2.0.4
> 
>