Re: [Qemu-devel] [PATCH v7 13/23] hw/acpi/aml-build: Make aml_buffer() definition consistent with the spec

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, May 14, 2015 at 05:19:32PM +0800, Shannon Zhao wrote:
> From: Shannon Zhao <shannon.zhao@linaro.org>
> 
> According to ACPI spec, DefBuffer can take two parameters: BufferSize
> and ByteList. Make it consistent with the spec. If we want to request
> uninitialized buffer, pass ByteList as NULL to aml_buffer() to
> reserve spaces.
> 
> Signed-off-by: Shannon Zhao <zhaoshenglong@huawei.com>
> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
> ---
>  hw/acpi/aml-build.c         | 15 ++++++++++++++-
>  include/hw/acpi/aml-build.h |  2 +-
>  2 files changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
> index b0e1dbc..6197896 100644
> --- a/hw/acpi/aml-build.c
> +++ b/hw/acpi/aml-build.c
> @@ -636,9 +636,22 @@ Aml *aml_resource_template(void)
>  }
>  
>  /* ACPI 1.0b: 16.2.5.4 Type 2 Opcodes Encoding: DefBuffer */
> -Aml *aml_buffer(void)
> +Aml *aml_buffer(int buffer_size, uint8_t *byte_list)
>  {
> +    int i;
>      Aml *var = aml_bundle(0x11 /* BufferOp */, AML_BUFFER);
> +
> +    for (i = 0; i < buffer_size; i++) {
> +        /* (byte_list == NULL) means requesting uninitialized buffer, only
> +         * need to reserve spaces.
> +         */

This comment documents API, belongs at top of function, not here.

> +        if (byte_list == NULL) {
> +            build_append_byte(var->buf, 0x0);
> +        } else {
> +            build_append_byte(var->buf, *(byte_list + i));

byte_list[i] would be clearer.

> +        }
> +    }
> +
>      return var;
>  }
>  
> diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
> index dd3b317..615f3c1 100644
> --- a/include/hw/acpi/aml-build.h
> +++ b/include/hw/acpi/aml-build.h
> @@ -261,7 +261,7 @@ Aml *aml_device(const char *name_format, ...) GCC_FMT_ATTR(1, 2);
>  Aml *aml_method(const char *name, int arg_count);
>  Aml *aml_if(Aml *predicate);
>  Aml *aml_package(uint8_t num_elements);
> -Aml *aml_buffer(void);
> +Aml *aml_buffer(int buffer_size, uint8_t *byte_list);
>  Aml *aml_resource_template(void);
>  Aml *aml_field(const char *name, AmlAccessType type, AmlUpdateRule rule);
>  Aml *aml_varpackage(uint32_t num_elements);
> -- 
> 2.1.0
>