[PATCH 1/3] ACPICA: Add support for FFH Opregion special context data

[Rafael J. Wysocki]

On Thu, Jun 16, 2022 at 11:01 AM Sudeep Holla <sudeep.holla at arm.com> wrote:
>
> FFH(Fixed Function Hardware) Opregion is approved to be added in ACPIC 6.5 via

s/ACPIC/ACPI/

> code first approach[1]. It requires special context data similar to GPIO and
> Generic Serial Bus as it needs to know platform specific offset and length.
>
> Add support for the special context data needed by FFH Opregion.
>
> FFH OpRegion enables advanced use of FFH on some architectures. For example,
> it could be used to easily proxy AML code to architecture-specific behavior
> (to ensure it is OS initiated)
>
> Actual behavior of FFH is ofcourse architecture specific and depends on
> the FFH bindings. The offset and length could have arch specific meaning
> or usage.
>
> [1] https://bugzilla.tianocore.org/show_bug.cgi?id=3598
>
> Signed-off-by: Sudeep Holla <sudeep.holla at arm.com>

This looks reasonable to me and I see that you've already submitted a
pull request to the upstream ACPICA.

> ---
>  drivers/acpi/acpica/evregion.c | 8 ++++++++
>  drivers/acpi/acpica/exfield.c  | 8 ++++++--
>  drivers/acpi/acpica/exserial.c | 6 ++++++
>  include/acpi/acconfig.h        | 2 ++
>  include/acpi/actypes.h         | 7 +++++++
>  5 files changed, 29 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/acpi/acpica/evregion.c b/drivers/acpi/acpica/evregion.c
> index b96b3a7e78e5..d5aed3249630 100644
> --- a/drivers/acpi/acpica/evregion.c
> +++ b/drivers/acpi/acpica/evregion.c
> @@ -172,6 +172,14 @@ acpi_ev_address_space_dispatch(union acpi_operand_object *region_obj,
>                         ctx->subspace_id = (u8)region_obj->region.address;
>                 }
>
> +               if (region_obj->region.space_id ==
> +                       ACPI_ADR_SPACE_FIXED_HARDWARE) {
> +                       struct acpi_ffh_info *ctx =
> +                           handler_desc->address_space.context;
> +
> +                       ctx->offset = region_obj->region.address;
> +                       ctx->length = region_obj->region.length;
> +               }
>                 /*
>                  * We must exit the interpreter because the region setup will
>                  * potentially execute control methods (for example, the _REG method
> diff --git a/drivers/acpi/acpica/exfield.c b/drivers/acpi/acpica/exfield.c
> index 2b89a496de65..657f4002f9dc 100644
> --- a/drivers/acpi/acpica/exfield.c
> +++ b/drivers/acpi/acpica/exfield.c
> @@ -141,7 +141,9 @@ acpi_ex_read_data_from_field(struct acpi_walk_state *walk_state,
>                     || obj_desc->field.region_obj->region.space_id ==
>                     ACPI_ADR_SPACE_IPMI
>                     || obj_desc->field.region_obj->region.space_id ==
> -                   ACPI_ADR_SPACE_PLATFORM_RT)) {
> +                   ACPI_ADR_SPACE_PLATFORM_RT
> +                   || obj_desc->field.region_obj->region.space_id ==
> +                   ACPI_ADR_SPACE_FIXED_HARDWARE)) {
>
>                 /* SMBus, GSBus, IPMI serial */
>
> @@ -305,7 +307,9 @@ acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
>                     || obj_desc->field.region_obj->region.space_id ==
>                     ACPI_ADR_SPACE_IPMI
>                     || obj_desc->field.region_obj->region.space_id ==
> -                   ACPI_ADR_SPACE_PLATFORM_RT)) {
> +                   ACPI_ADR_SPACE_PLATFORM_RT
> +                   || obj_desc->field.region_obj->region.space_id ==
> +                   ACPI_ADR_SPACE_FIXED_HARDWARE)) {
>
>                 /* SMBus, GSBus, IPMI serial */
>
> diff --git a/drivers/acpi/acpica/exserial.c b/drivers/acpi/acpica/exserial.c
> index 4da20d7845df..fd63f2042514 100644
> --- a/drivers/acpi/acpica/exserial.c
> +++ b/drivers/acpi/acpica/exserial.c
> @@ -323,6 +323,12 @@ acpi_ex_write_serial_bus(union acpi_operand_object *source_desc,
>                 function = ACPI_WRITE;
>                 break;
>
> +       case ACPI_ADR_SPACE_FIXED_HARDWARE:
> +
> +               buffer_length = ACPI_FFH_INPUT_BUFFER_SIZE;
> +               function = ACPI_WRITE;
> +               break;
> +
>         default:
>                 return_ACPI_STATUS(AE_AML_INVALID_SPACE_ID);
>         }
> diff --git a/include/acpi/acconfig.h b/include/acpi/acconfig.h
> index c3ae3ea88e17..02e57191c1fd 100644
> --- a/include/acpi/acconfig.h
> +++ b/include/acpi/acconfig.h
> @@ -190,6 +190,8 @@
>
>  #define ACPI_PRM_INPUT_BUFFER_SIZE      26
>
> +#define ACPI_FFH_INPUT_BUFFER_SIZE      144
> +
>  /* _sx_d and _sx_w control methods */
>
>  #define ACPI_NUM_sx_d_METHODS           4
> diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h
> index 3491e454b2ab..1b4f81f1ac5d 100644
> --- a/include/acpi/actypes.h
> +++ b/include/acpi/actypes.h
> @@ -1115,6 +1115,13 @@ struct acpi_pcc_info {
>         u8 *internal_buffer;
>  };
>
> +/* Special Context data for FFH Opregion (ACPI 6.5) */
> +
> +struct acpi_ffh_info {
> +       u64 offset;
> +       u64 length;
> +};
> +
>  typedef
>  acpi_status (*acpi_adr_space_setup) (acpi_handle region_handle,
>                                      u32 function,
> --
> 2.36.1
>