On Sat, Feb 23, 2019 at 1:09 AM Erik Schmauss <erik.schmauss@xxxxxxxxx> wrote: > > ACPICA commit a4849944e80f97970e99843f4975850753584a4e > > This change adds PCC operation region support in the AML interpreter > and a default handler for acpiexec. According to the specification, > the PCC operation region performs a transaction when the COMD field > is written. This allows ASL to write data to other fields before > sending the data. > > In order to accommodate this protocol, a temorary buffer is added > to the regionfield object to accumulate writes. If any offset that > spans COMD is written, the temporary buffer is sent to the PCC > operation region handler to be processed. > > This change also renames the PCC keyword to platform_comm_channel. > > Link: https://github.com/acpica/acpica/commit/a4849944 > Reviewed-by: Kyle Pelton <kyle.d.pelton@xxxxxxxxx> > Signed-off-by: Erik Schmauss <erik.schmauss@xxxxxxxxx> > Signed-off-by: Bob Moore <robert.moore@xxxxxxxxx> I've applied this patch instead of the previous version, thanks! > --- > drivers/acpi/acpica/acobject.h | 1 + > drivers/acpi/acpica/dsfield.c | 7 ++++ > drivers/acpi/acpica/exfield.c | 68 ++++++++++++++++++++++++++++++++++ > drivers/acpi/acpica/utdelete.c | 4 ++ > 4 files changed, 80 insertions(+) > > diff --git a/drivers/acpi/acpica/acobject.h b/drivers/acpi/acpica/acobject.h > index 0edf8fca7567..b2ef703d7df8 100644 > --- a/drivers/acpi/acpica/acobject.h > +++ b/drivers/acpi/acpica/acobject.h > @@ -239,6 +239,7 @@ struct acpi_object_region_field { > union acpi_operand_object *region_obj; /* Containing op_region object */ > u8 *resource_buffer; /* resource_template for serial regions/fields */ > u16 pin_number_index; /* Index relative to previous Connection/Template */ > + u8 *internal_pcc_buffer; /* Internal buffer for fields associated with PCC */ > }; > > struct acpi_object_bank_field { > diff --git a/drivers/acpi/acpica/dsfield.c b/drivers/acpi/acpica/dsfield.c > index d51216c9d891..cf4e061bb0f0 100644 > --- a/drivers/acpi/acpica/dsfield.c > +++ b/drivers/acpi/acpica/dsfield.c > @@ -518,6 +518,13 @@ acpi_ds_create_field(union acpi_parse_object *op, > info.region_node = region_node; > > status = acpi_ds_get_field_names(&info, walk_state, arg->common.next); > + if (info.region_node->object->region.space_id == > + ACPI_ADR_SPACE_PLATFORM_COMM > + && !(region_node->object->field.internal_pcc_buffer = > + ACPI_ALLOCATE_ZEROED(info.region_node->object->region. > + length))) { > + return_ACPI_STATUS(AE_NO_MEMORY); > + } > return_ACPI_STATUS(status); > } > > diff --git a/drivers/acpi/acpica/exfield.c b/drivers/acpi/acpica/exfield.c > index 7dcdde094582..3760f96b19f9 100644 > --- a/drivers/acpi/acpica/exfield.c > +++ b/drivers/acpi/acpica/exfield.c > @@ -41,6 +41,17 @@ const u8 acpi_protocol_lengths[] = { > 0xFF /* F - ATTRIB_RAW_PROCESS_BYTES */ > }; > > +#define PCC_MASTER_SUBSPACE 3 > + > +/* > + * The following macros determine a given offset is a COMD field. > + * According to the specification, generic subspaces (types 0-2) contains a > + * 2-byte COMD field at offset 4 and master subspaces (type 3) contains a 4-byte > + * COMD field starting at offset 12. > + */ > +#define GENERIC_SUBSPACE_COMMAND(a) (4 == a || a == 5) > +#define MASTER_SUBSPACE_COMMAND(a) (12 <= a && a <= 15) > + > /******************************************************************************* > * > * FUNCTION: acpi_ex_get_protocol_buffer_length > @@ -177,6 +188,25 @@ acpi_ex_read_data_from_field(struct acpi_walk_state *walk_state, > > status = acpi_ex_read_gpio(obj_desc, buffer); > goto exit; > + } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) && > + (obj_desc->field.region_obj->region.space_id == > + ACPI_ADR_SPACE_PLATFORM_COMM)) { > + /* > + * Reading from a PCC field unit does not require the handler because > + * it only requires reading from the internal_pcc_buffer. > + */ > + ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, > + "PCC FieldRead bits %u\n", > + obj_desc->field.bit_length)); > + > + memcpy(buffer, > + obj_desc->field.region_obj->field.internal_pcc_buffer + > + obj_desc->field.base_byte_offset, > + (acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field. > + bit_length)); > + > + *ret_buffer_desc = buffer_desc; > + return AE_OK; > } > > ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, > @@ -229,6 +259,7 @@ acpi_ex_write_data_to_field(union acpi_operand_object *source_desc, > { > acpi_status status; > u32 buffer_length; > + u32 data_length; > void *buffer; > > ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc); > @@ -272,6 +303,43 @@ acpi_ex_write_data_to_field(union acpi_operand_object *source_desc, > acpi_ex_write_serial_bus(source_desc, obj_desc, > result_desc); > return_ACPI_STATUS(status); > + } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) && > + (obj_desc->field.region_obj->region.space_id == > + ACPI_ADR_SPACE_PLATFORM_COMM)) { > + /* > + * According to the spec a write to the COMD field will invoke the > + * region handler. Otherwise, write to the pcc_internal buffer. This > + * implementation will use the offsets specified rather than the name > + * of the field. This is considered safer because some firmware tools > + * are known to obfiscate named objects. > + */ > + data_length = > + (acpi_size)ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field. > + bit_length); > + memcpy(obj_desc->field.region_obj->field.internal_pcc_buffer + > + obj_desc->field.base_byte_offset, > + source_desc->buffer.pointer, data_length); > + if ((obj_desc->field.region_obj->region.address == > + PCC_MASTER_SUBSPACE > + && MASTER_SUBSPACE_COMMAND(obj_desc->field. > + base_byte_offset)) > + || GENERIC_SUBSPACE_COMMAND(obj_desc->field. > + base_byte_offset)) { > + > + /* Perform the write */ > + > + ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, > + "PCC COMD field has been written. Invoking PCC handler now.\n")); > + > + status = > + acpi_ex_access_region(obj_desc, 0, > + (u64 *)obj_desc->field. > + region_obj->field. > + internal_pcc_buffer, > + ACPI_WRITE); > + return_ACPI_STATUS(status); > + } > + return (AE_OK); > } > > /* Get a pointer to the data to be written */ > diff --git a/drivers/acpi/acpica/utdelete.c b/drivers/acpi/acpica/utdelete.c > index 8cc4392c61f3..eee263cb7beb 100644 > --- a/drivers/acpi/acpica/utdelete.c > +++ b/drivers/acpi/acpica/utdelete.c > @@ -257,6 +257,10 @@ static void acpi_ut_delete_internal_obj(union acpi_operand_object *object) > > acpi_ut_delete_object_desc(second_desc); > } > + if (object->field.internal_pcc_buffer) { > + ACPI_FREE(object->field.internal_pcc_buffer); > + } > + > break; > > case ACPI_TYPE_BUFFER_FIELD: > -- > 2.17.1 >
