[v4,04/20] ppc/pnv: add a PIR handler to PnvChip

The Processor Identification Register (PIR) is a register that holds a
processor identifier which is used for bus transactions (XSCOM) and
for processor differentiation in multiprocessor systems. It also used
in the interrupt vector entries (IVE) to identify the thread serving
the interrupts.

P9 and P8 have some differences in the CPU PIR encoding.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
---

 Changes since v3 :

 - added a couple more comments on the bits definition
  
 hw/ppc/pnv.c         | 30 ++++++++++++++++++++++++++++++
 include/hw/ppc/pnv.h |  2 ++
 2 files changed, 32 insertions(+)

On Mon, Oct 03, 2016 at 09:24:40AM +0200, Cédric Le Goater wrote:
> The Processor Identification Register (PIR) is a register that holds a
> processor identifier which is used for bus transactions (XSCOM) and
> for processor differentiation in multiprocessor systems. It also used
> in the interrupt vector entries (IVE) to identify the thread serving
> the interrupts.
> 
> P9 and P8 have some differences in the CPU PIR encoding.
> 
> Signed-off-by: Cédric Le Goater <clg@kaod.org>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

Looks fine, although it's a bit hard to be sure since I haven't read
the patches which actually use this yet.

> ---
> 
>  Changes since v3 :
> 
>  - added a couple more comments on the bits definition
>   
>  hw/ppc/pnv.c         | 30 ++++++++++++++++++++++++++++++
>  include/hw/ppc/pnv.h |  2 ++
>  2 files changed, 32 insertions(+)
> 
> diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
> index fc930be94f53..758c849702a0 100644
> --- a/hw/ppc/pnv.c
> +++ b/hw/ppc/pnv.c
> @@ -239,6 +239,32 @@ static void ppc_powernv_init(MachineState *machine)
>      g_free(chip_typename);
>  }
>  
> +/*
> + *    0:21  Reserved - Read as zeros
> + *   22:24  Chip ID
> + *   25:28  Core number
> + *   29:31  Thread ID
> + */
> +static uint32_t pnv_chip_core_pir_p8(PnvChip *chip, uint32_t core_id)
> +{
> +    return (chip->chip_id << 7) | (core_id << 3);
> +}
> +
> +/*
> + *    0:48  Reserved - Read as zeroes
> + *   49:52  Node ID
> + *   53:55  Chip ID
> + *   56     Reserved - Read as zero
> + *   57:61  Core number
> + *   62:63  Thread ID
> + *
> + * We only care about the lower bits. uint32_t is fine for the moment.
> + */
> +static uint32_t pnv_chip_core_pir_p9(PnvChip *chip, uint32_t core_id)
> +{
> +    return (chip->chip_id << 8) | (core_id << 2);
> +}
> +
>  /* Allowed core identifiers on a POWER8 Processor Chip :
>   *
>   * <EX0 reserved>
> @@ -274,6 +300,7 @@ static void pnv_chip_power8e_class_init(ObjectClass *klass, void *data)
>      k->chip_type = PNV_CHIP_POWER8E;
>      k->chip_cfam_id = 0x221ef04980000000ull;  /* P8 Murano DD2.1 */
>      k->cores_mask = POWER8E_CORE_MASK;
> +    k->core_pir = pnv_chip_core_pir_p8;
>      dc->desc = "PowerNV Chip POWER8E";
>  }
>  
> @@ -293,6 +320,7 @@ static void pnv_chip_power8_class_init(ObjectClass *klass, void *data)
>      k->chip_type = PNV_CHIP_POWER8;
>      k->chip_cfam_id = 0x220ea04980000000ull; /* P8 Venice DD2.0 */
>      k->cores_mask = POWER8_CORE_MASK;
> +    k->core_pir = pnv_chip_core_pir_p8;
>      dc->desc = "PowerNV Chip POWER8";
>  }
>  
> @@ -312,6 +340,7 @@ static void pnv_chip_power8nvl_class_init(ObjectClass *klass, void *data)
>      k->chip_type = PNV_CHIP_POWER8NVL;
>      k->chip_cfam_id = 0x120d304980000000ull;  /* P8 Naples DD1.0 */
>      k->cores_mask = POWER8_CORE_MASK;
> +    k->core_pir = pnv_chip_core_pir_p8;
>      dc->desc = "PowerNV Chip POWER8NVL";
>  }
>  
> @@ -331,6 +360,7 @@ static void pnv_chip_power9_class_init(ObjectClass *klass, void *data)
>      k->chip_type = PNV_CHIP_POWER9;
>      k->chip_cfam_id = 0x100d104980000000ull; /* P9 Nimbus DD1.0 */
>      k->cores_mask = POWER9_CORE_MASK;
> +    k->core_pir = pnv_chip_core_pir_p9;
>      dc->desc = "PowerNV Chip POWER9";
>  }
>  
> diff --git a/include/hw/ppc/pnv.h b/include/hw/ppc/pnv.h
> index 2c225c928974..c676f800e28e 100644
> --- a/include/hw/ppc/pnv.h
> +++ b/include/hw/ppc/pnv.h
> @@ -56,6 +56,8 @@ typedef struct PnvChipClass {
>      PnvChipType  chip_type;
>      uint64_t     chip_cfam_id;
>      uint64_t     cores_mask;
> +
> +    uint32_t (*core_pir)(PnvChip *chip, uint32_t core_id);
>  } PnvChipClass;
>  
>  #define TYPE_PNV_CHIP_POWER8E TYPE_PNV_CHIP "-POWER8E"

On 10/07/2016 06:34 AM, David Gibson wrote:
> On Mon, Oct 03, 2016 at 09:24:40AM +0200, Cédric Le Goater wrote:
>> The Processor Identification Register (PIR) is a register that holds a
>> processor identifier which is used for bus transactions (XSCOM) and
>> for processor differentiation in multiprocessor systems. It also used
>> in the interrupt vector entries (IVE) to identify the thread serving
>> the interrupts.
>>
>> P9 and P8 have some differences in the CPU PIR encoding.
>>
>> Signed-off-by: Cédric Le Goater <clg@kaod.org>
> 
> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> 
> Looks fine, although it's a bit hard to be sure since I haven't read
> the patches which actually use this yet.

This is used in the next patch when the pir of the PnvCore is initialized :

+        object_property_set_int(OBJECT(pnv_core),
+                                pcc->core_pir(chip, core_hwid),
+                                "pir", &error_fatal);

Then this "pir" property of the core is added as a property alias to 
PowerPCCPU, which uses it to initialize SPR_PIR.

Thanks,

C.