[Xen-devel] RE: [PATCH] ACPI: add _PDC input override mechanism

["Tian, Kevin" <kevin.tian@xxxxxxxxx>]

> From: Jan Beulich [mailto:JBeulich@xxxxxxxxxx]
> Sent: Monday, August 22, 2011 2:40 PM
> 
> In order to have Dom0 call _PDC with input fully representing Xen's
> capabilities, and in order to avoid building knowledge of Xen
> implementation details into Dom0, this provides a mechanism by which
> the Dom0 kernel can, once it filled the _PDC input buffer according to
> its own knowledge, present the buffer to Xen to apply overrides for
> the parts of the C-, P-, and T-state management that it controls. This
> is particularly to address the dependency of Xen using MWAIT to enter
> certain C-states on the availability of the break-on-interrupt
> extension (which the Dom0 kernel should have no need to know about).
> 
> The patch, in order to apply correctly, depends on the one titled "pm:
> don't truncate processors' ACPI IDs to 8 bits" sent at the end of last
> week.
> 
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>

looks good to me.

Thanks
Kevin

> 
> --- a/xen/arch/ia64/linux-xen/acpi.c
> +++ b/xen/arch/ia64/linux-xen/acpi.c
> @@ -241,6 +241,13 @@ int get_cpu_id(u32 acpi_id)
> 
>       return -1;
>  }
> +
> +int arch_acpi_set_pdc_bits(u32 acpi_id, u32 *pdc, u32 mask)
> +{
> +     pdc[2] |= ACPI_PDC_EST_CAPABILITY_SMP & mask;
> +     return 0;
> +}
> +
>  #endif
> 
>  static int __init
> --- a/xen/arch/x86/acpi/cpu_idle.c
> +++ b/xen/arch/x86/acpi/cpu_idle.c
> @@ -643,12 +643,6 @@ static int cpuidle_init_cpu(int cpu)
>      return 0;
>  }
> 
> -#define CPUID_MWAIT_LEAF (5)
> -#define CPUID5_ECX_EXTENSIONS_SUPPORTED (0x1)
> -#define CPUID5_ECX_INTERRUPT_BREAK      (0x2)
> -
> -#define MWAIT_ECX_INTERRUPT_BREAK       (0x1)
> -
>  #define MWAIT_SUBSTATE_MASK (0xf)
>  #define MWAIT_SUBSTATE_SIZE (4)
> 
> --- a/xen/arch/x86/acpi/lib.c
> +++ b/xen/arch/x86/acpi/lib.c
> @@ -81,3 +81,47 @@ unsigned int acpi_get_processor_id(unsig
> 
>       return INVALID_ACPIID;
>  }
> +
> +static void get_mwait_ecx(void *info)
> +{
> +     *(u32 *)info = cpuid_ecx(CPUID_MWAIT_LEAF);
> +}
> +
> +int arch_acpi_set_pdc_bits(u32 acpi_id, u32 *pdc, u32 mask)
> +{
> +     unsigned int cpu = get_cpu_id(acpi_id);
> +     struct cpuinfo_x86 *c;
> +     u32 ecx;
> +
> +     if (!(acpi_id + 1))
> +             c = &boot_cpu_data;
> +     else if (cpu >= NR_CPUS || !cpu_online(cpu))
> +             return -EINVAL;
> +     else
> +             c = cpu_data + cpu;
> +
> +     pdc[2] |= ACPI_PDC_C_CAPABILITY_SMP & mask;
> +
> +     if (cpu_has(c, X86_FEATURE_EST))
> +             pdc[2] |= ACPI_PDC_EST_CAPABILITY_SWSMP & mask;
> +
> +     if (cpu_has(c, X86_FEATURE_ACPI))
> +             pdc[2] |= ACPI_PDC_T_FFH & mask;
> +
> +     /*
> +      * If mwait/monitor or its break-on-interrupt extension are
> +      * unsupported, Cx_FFH will be disabled.
> +      */
> +     if (!cpu_has(c, X86_FEATURE_MWAIT) ||
> +         c->cpuid_level < CPUID_MWAIT_LEAF)
> +             ecx = 0;
> +     else if (c == &boot_cpu_data || cpu == smp_processor_id())
> +             ecx = cpuid_ecx(CPUID_MWAIT_LEAF);
> +     else
> +             on_selected_cpus(cpumask_of(cpu), get_mwait_ecx, &ecx, 1);
> +     if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
> +         !(ecx & CPUID5_ECX_INTERRUPT_BREAK))
> +             pdc[2] &= ~(ACPI_PDC_C_C1_FFH | ACPI_PDC_C_C2C3_FFH);
> +
> +     return 0;
> +}
> --- a/xen/arch/x86/platform_hypercall.c
> +++ b/xen/arch/x86/platform_hypercall.c
> @@ -416,6 +416,15 @@ ret_t do_platform_op(XEN_GUEST_HANDLE(xe
>              ret = -EINVAL;
>              break;
> 
> +        case XEN_PM_PDC:
> +        {
> +            XEN_GUEST_HANDLE(uint32) pdc;
> +
> +            guest_from_compat_handle(pdc, op->u.set_pminfo.u.pdc);
> +            ret = acpi_set_pdc_bits(op->u.set_pminfo.id, pdc);
> +        }
> +        break;
> +
>          default:
>              ret = -EINVAL;
>              break;
> --- a/xen/drivers/acpi/pmstat.c
> +++ b/xen/drivers/acpi/pmstat.c
> @@ -517,3 +517,34 @@ int do_pm_op(struct xen_sysctl_pm_op *op
> 
>      return ret;
>  }
> +
> +int acpi_set_pdc_bits(u32 acpi_id, XEN_GUEST_HANDLE(uint32) pdc)
> +{
> +    u32 bits[3];
> +    int ret;
> +
> +    if ( copy_from_guest(bits, pdc, 2) )
> +        ret = -EFAULT;
> +    else if ( bits[0] != ACPI_PDC_REVISION_ID || !bits[1] )
> +        ret = -EINVAL;
> +    else if ( copy_from_guest_offset(bits + 2, pdc, 2, 1) )
> +        ret = -EFAULT;
> +    else
> +    {
> +        u32 mask = 0;
> +
> +        if ( xen_processor_pmbits & XEN_PROCESSOR_PM_CX )
> +            mask |= ACPI_PDC_C_MASK | ACPI_PDC_SMP_C1PT;
> +        if ( xen_processor_pmbits & XEN_PROCESSOR_PM_PX )
> +            mask |= ACPI_PDC_P_MASK | ACPI_PDC_SMP_C1PT;
> +        if ( xen_processor_pmbits & XEN_PROCESSOR_PM_TX )
> +            mask |= ACPI_PDC_T_MASK | ACPI_PDC_SMP_C1PT;
> +        bits[2] &= (ACPI_PDC_C_MASK | ACPI_PDC_P_MASK |
> ACPI_PDC_T_MASK |
> +                    ACPI_PDC_SMP_C1PT) & ~mask;
> +        ret = arch_acpi_set_pdc_bits(acpi_id, bits, mask);
> +    }
> +    if ( !ret )
> +        ret = copy_to_guest_offset(pdc, 2, bits + 2, 1);
> +
> +    return ret;
> +}
> --- a/xen/include/acpi/cpufreq/processor_perf.h
> +++ b/xen/include/acpi/cpufreq/processor_perf.h
> @@ -3,10 +3,10 @@
> 
>  #include <public/platform.h>
>  #include <public/sysctl.h>
> +#include <xen/acpi.h>
> 
>  #define XEN_PX_INIT 0x80000000
> 
> -int get_cpu_id(u32);
>  int powernow_cpufreq_init(void);
>  unsigned int powernow_register_driver(void);
>  unsigned int get_measured_perf(unsigned int cpu, unsigned int flag);
> --- a/xen/include/acpi/pdc_intel.h
> +++ b/xen/include/acpi/pdc_intel.h
> @@ -4,6 +4,8 @@
>  #ifndef __PDC_INTEL_H__
>  #define __PDC_INTEL_H__
> 
> +#define ACPI_PDC_REVISION_ID         1
> +
>  #define ACPI_PDC_P_FFH                       (0x0001)
>  #define ACPI_PDC_C_C1_HALT           (0x0002)
>  #define ACPI_PDC_T_FFH                       (0x0004)
> @@ -14,6 +16,7 @@
>  #define ACPI_PDC_SMP_T_SWCOORD               (0x0080)
>  #define ACPI_PDC_C_C1_FFH            (0x0100)
>  #define ACPI_PDC_C_C2C3_FFH          (0x0200)
> +#define ACPI_PDC_SMP_P_HWCOORD               (0x0800)
> 
>  #define ACPI_PDC_EST_CAPABILITY_SMP  (ACPI_PDC_SMP_C1PT | \
>                                        ACPI_PDC_C_C1_HALT | \
> @@ -22,6 +25,7 @@
>  #define ACPI_PDC_EST_CAPABILITY_SWSMP        (ACPI_PDC_SMP_C1PT | \
>                                        ACPI_PDC_C_C1_HALT | \
>                                        ACPI_PDC_SMP_P_SWCOORD | \
> +                                      ACPI_PDC_SMP_P_HWCOORD | \
>                                        ACPI_PDC_P_FFH)
> 
>  #define ACPI_PDC_C_CAPABILITY_SMP    (ACPI_PDC_SMP_C2C3  | \
> @@ -30,4 +34,17 @@
>                                        ACPI_PDC_C_C1_FFH  | \
>                                        ACPI_PDC_C_C2C3_FFH)
> 
> +#define ACPI_PDC_C_MASK                      (ACPI_PDC_C_C1_HALT | \
> +                                      ACPI_PDC_C_C1_FFH | \
> +                                      ACPI_PDC_SMP_C2C3 | \
> +                                      ACPI_PDC_SMP_C_SWCOORD | \
> +                                      ACPI_PDC_C_C2C3_FFH)
> +
> +#define ACPI_PDC_P_MASK                      (ACPI_PDC_P_FFH | \
> +                                      ACPI_PDC_SMP_P_SWCOORD | \
> +                                      ACPI_PDC_SMP_P_HWCOORD)
> +
> +#define ACPI_PDC_T_MASK                      (ACPI_PDC_T_FFH | \
> +                                      ACPI_PDC_SMP_T_SWCOORD)
> +
>  #endif                               /* __PDC_INTEL_H__ */
> --- a/xen/include/asm-x86/cpufeature.h
> +++ b/xen/include/asm-x86/cpufeature.h
> @@ -152,6 +152,10 @@
>  #define boot_cpu_has(bit)    test_bit(bit, boot_cpu_data.x86_capability)
>  #define cpufeat_mask(idx)       (1u << ((idx) & 31))
> 
> +#define CPUID_MWAIT_LEAF                5
> +#define CPUID5_ECX_EXTENSIONS_SUPPORTED 0x1
> +#define CPUID5_ECX_INTERRUPT_BREAK      0x2
> +
>  #ifdef __i386__
>  #define cpu_has_vme          boot_cpu_has(X86_FEATURE_VME)
>  #define cpu_has_de           boot_cpu_has(X86_FEATURE_DE)
> --- a/xen/include/public/platform.h
> +++ b/xen/include/public/platform.h
> @@ -304,6 +304,7 @@ DEFINE_XEN_GUEST_HANDLE(xenpf_getidletim
>  #define XEN_PM_CX   0
>  #define XEN_PM_PX   1
>  #define XEN_PM_TX   2
> +#define XEN_PM_PDC  3
> 
>  /* Px sub info type */
>  #define XEN_PX_PCT   1
> @@ -401,6 +402,7 @@ struct xenpf_set_processor_pminfo {
>      union {
>          struct xen_processor_power          power;/* Cx: _CST/_CSD */
>          struct xen_processor_performance    perf; /* Px:
> _PPC/_PCT/_PSS/_PSD */
> +        XEN_GUEST_HANDLE(uint32)            pdc;  /* _PDC */
>      } u;
>  };
>  typedef struct xenpf_set_processor_pminfo xenpf_set_processor_pminfo_t;
> --- a/xen/include/xen/acpi.h
> +++ b/xen/include/xen/acpi.h
> @@ -322,6 +322,8 @@ static inline int acpi_boot_table_init(v
> 
>  #endif       /*!CONFIG_ACPI_BOOT*/
> 
> +int get_cpu_id(u32 acpi_id);
> +
>  unsigned int acpi_register_gsi (u32 gsi, int edge_level, int 
> active_high_low);
>  int acpi_gsi_to_irq (u32 gsi, unsigned int *irq);
> 
> @@ -358,6 +360,9 @@ static inline unsigned int acpi_get_csta
>  static inline void acpi_set_cstate_limit(unsigned int new_limit) { return; }
>  #endif
> 
> +int acpi_set_pdc_bits(u32 acpi_id, XEN_GUEST_HANDLE(uint32));
> +int arch_acpi_set_pdc_bits(u32 acpi_id, u32 *, u32 mask);
> +
>  #ifdef CONFIG_ACPI_NUMA
>  int acpi_get_pxm(acpi_handle handle);
>  #else
> 


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