Re: [RFC PATCH v2 08/13] hw/acpi/aml-build: add processor hierarchy node structure

[Andrew Jones]

On Tue, Oct 20, 2020 at 09:14:35PM +0800, Ying Fang wrote:
> Add the processor hierarchy node structures to build ACPI information
> for CPU topology. Three helpers are introduced:
> 
> (1) build_socket_hierarchy for socket description structure
> (2) build_processor_hierarchy for processor description structure
> (3) build_smt_hierarchy for thread (logic processor) description structure
> 
> Signed-off-by: Ying Fang <fangying1@huawei.com>
> Signed-off-by: Henglong Fan <fanhenglong@huawei.com>
> ---
>  hw/acpi/aml-build.c         | 37 +++++++++++++++++++++++++++++++++++++
>  include/hw/acpi/aml-build.h |  7 +++++++
>  2 files changed, 44 insertions(+)
> 
> diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
> index 3792ba96ce..da3b41b514 100644
> --- a/hw/acpi/aml-build.c
> +++ b/hw/acpi/aml-build.c
> @@ -1770,6 +1770,43 @@ void build_slit(GArray *table_data, BIOSLinker 
> *linker, MachineState *ms)
>                   table_data->len - slit_start, 1, NULL, NULL);
>  }
>  
> +/*
> + * ACPI 6.3: 5.2.29.1 Processor hierarchy node structure (Type 0)
> + */
> +void build_socket_hierarchy(GArray *tbl, uint32_t parent, uint32_t id)
> +{
> +    build_append_byte(tbl, 0);          /* Type 0 - processor */
> +    build_append_byte(tbl, 20);         /* Length, no private resources */
> +    build_append_int_noprefix(tbl, 0, 2);  /* Reserved */
> +    build_append_int_noprefix(tbl, 1, 4);  /* Flags: Physical package */
> +    build_append_int_noprefix(tbl, parent, 4);  /* Parent */
> +    build_append_int_noprefix(tbl, id, 4);     /* ACPI processor ID */
> +    build_append_int_noprefix(tbl, 0, 4);  /* Number of private resources */
> +}
> +
> +void build_processor_hierarchy(GArray *tbl, uint32_t flags,
> +                               uint32_t parent, uint32_t id)
> +{
> +    build_append_byte(tbl, 0);          /* Type 0 - processor */
> +    build_append_byte(tbl, 20);         /* Length, no private resources */
> +    build_append_int_noprefix(tbl, 0, 2);      /* Reserved */
> +    build_append_int_noprefix(tbl, flags, 4);  /* Flags */
> +    build_append_int_noprefix(tbl, parent, 4); /* Parent */
> +    build_append_int_noprefix(tbl, id, 4);     /* ACPI processor ID */
> +    build_append_int_noprefix(tbl, 0, 4);  /* Number of private resources */
> +}
> +
> +void build_smt_hierarchy(GArray *tbl, uint32_t parent, uint32_t id)
> +{
> +    build_append_byte(tbl, 0);            /* Type 0 - processor */
> +    build_append_byte(tbl, 20);           /* Length, add private resources */
> +    build_append_int_noprefix(tbl, 0, 2); /* Reserved */
> +    build_append_int_noprefix(tbl, 0x0e, 4);    /* Processor is a thread */
> +    build_append_int_noprefix(tbl, parent , 4); /* parent */
> +    build_append_int_noprefix(tbl, id, 4);      /* ACPI processor ID */
> +    build_append_int_noprefix(tbl, 0, 4);       /* Num of private resources 
> */
> +}
> +
>  /* build rev1/rev3/rev5.1 FADT */
>  void build_fadt(GArray *tbl, BIOSLinker *linker, const AcpiFadtData *f,
>                  const char *oem_id, const char *oem_table_id)
> diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
> index fe0055fffb..56474835a7 100644
> --- a/include/hw/acpi/aml-build.h
> +++ b/include/hw/acpi/aml-build.h
> @@ -437,6 +437,13 @@ void build_srat_memory(AcpiSratMemoryAffinity *numamem, 
> uint64_t base,
>  
>  void build_slit(GArray *table_data, BIOSLinker *linker, MachineState *ms);
>  
> +void build_socket_hierarchy(GArray *tbl, uint32_t parent, uint32_t id);
> +
> +void build_processor_hierarchy(GArray *tbl, uint32_t flags,
> +                               uint32_t parent, uint32_t id);
> +
> +void build_smt_hierarchy(GArray *tbl, uint32_t parent, uint32_t id);
> +
>  void build_fadt(GArray *tbl, BIOSLinker *linker, const AcpiFadtData *f,
>                  const char *oem_id, const char *oem_table_id);
>  
> -- 
> 2.23.0
> 
>

I don't think we need three 99% identical functions that only differ by a
flags field, especially when one of the functions is the generic form that
takes flags as an argument. At the very least this should be

void build_processor_hierarchy(tbl, flags, parent id)
{
  ...
}

void build_socket_hierarchy(tbl, parent, id)
{
  build_processor_hierarchy(tbl, 1, parent, id);
}

void build_smt_hierarchy(tbl, parent, id)
{
  build_processor_hierarchy(tbl, 0xe, parent, id);
}

Thanks,
drew