Re: [PATCH v3 05/35] acpi: build_fadt: use acpi_table_begin()/acpi_table_end() instead of build_header()

[Eric Auger]

On 9/7/21 4:47 PM, Igor Mammedov wrote:
> it replaces error-prone pointer arithmetic for build_header() API,
> with 2 calls to start and finish table creation,
> which hides offsets magic from API user.
> 
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Eric
> ---
> v3:
>   * s/acpi_init_table|acpi_table_composed/acpi_table_begin|acpi_table_end/
> ---
>  hw/acpi/aml-build.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
> index e54face23d..dbf3ffe889 100644
> --- a/hw/acpi/aml-build.c
> +++ b/hw/acpi/aml-build.c
> @@ -1978,9 +1978,10 @@ void build_fadt(GArray *tbl, BIOSLinker *linker, const 
> AcpiFadtData *f,
>                  const char *oem_id, const char *oem_table_id)
>  {
>      int off;
> -    int fadt_start = tbl->len;
> +    AcpiTable table = { .sig = "FACP", .rev = f->rev,
> +                        .oem_id = oem_id, .oem_table_id = oem_table_id };
>  
> -    acpi_data_push(tbl, sizeof(AcpiTableHeader));
> +    acpi_table_begin(&table, tbl);
>  
>      /* FACS address to be filled by Guest linker at runtime */
>      off = tbl->len;
> @@ -2044,7 +2045,7 @@ void build_fadt(GArray *tbl, BIOSLinker *linker, const 
> AcpiFadtData *f,
>      build_append_int_noprefix(tbl, f->flags, 4); /* Flags */
>  
>      if (f->rev == 1) {
> -        goto build_hdr;
> +        goto done;
>      }
>  
>      build_append_gas_from_struct(tbl, &f->reset_reg); /* RESET_REG */
> @@ -2081,7 +2082,7 @@ void build_fadt(GArray *tbl, BIOSLinker *linker, const 
> AcpiFadtData *f,
>      build_append_gas(tbl, AML_AS_SYSTEM_MEMORY, 0 , 0, 0, 0); /* X_GPE1_BLK 
> */
>  
>      if (f->rev <= 4) {
> -        goto build_hdr;
> +        goto done;
>      }
>  
>      /* SLEEP_CONTROL_REG */
> @@ -2092,9 +2093,8 @@ void build_fadt(GArray *tbl, BIOSLinker *linker, const 
> AcpiFadtData *f,
>      /* TODO: extra fields need to be added to support revisions above rev5 */
>      assert(f->rev == 5);
>  
> -build_hdr:
> -    build_header(linker, tbl, (void *)(tbl->data + fadt_start),
> -                 "FACP", tbl->len - fadt_start, f->rev, oem_id, 
> oem_table_id);
> +done:
> +    acpi_table_end(linker, &table);
>  }
>  
>  #ifdef CONFIG_TPM
>