RE: [V8 PATCH 1/3] ACPICA: Add ACPI _CLS processing

From: Moore, Robert
Date: Thu Apr 16 2015 - 23:48:33 EST


Yes, this is a good question that we should think about.
Bob


> -----Original Message-----
> From: Zheng, Lv
> Sent: Thursday, April 16, 2015 6:46 PM
> To: Suravee Suthikulpanit; rjw@xxxxxxxxxxxxx;
> mika.westerberg@xxxxxxxxxxxxxxx; Moore, Robert; hanjun.guo@xxxxxxxxxx
> Cc: lenb@xxxxxxxxxx; hdegoede@xxxxxxxxxx; tj@xxxxxxxxxx;
> mjg59@xxxxxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; al.stone@xxxxxxxxxx;
> graeme.gregory@xxxxxxxxxx; leo.duran@xxxxxxx; linux-ide@xxxxxxxxxxxxxxx;
> linux-acpi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linaro-
> acpi@xxxxxxxxxxxxxxxx
> Subject: RE: [V8 PATCH 1/3] ACPICA: Add ACPI _CLS processing
>
> Before back porting this to ACPICA, let me ask one simple question.
> According to the spec, the _CLS is optional and PCI specific.
> So why should we implement it in ACPICA core not OSPM specific modules?
> If this need to be implemented in ACPICA, then what about the following
> device identification objects?
> _DDN, _HRV, _MLS, _PLD, _STR, _SUN
>
> Thanks and best regards
> -Lv
>
> > From: Suravee Suthikulpanit [mailto:Suravee.Suthikulpanit@xxxxxxx]
> > Sent: Tuesday, March 31, 2015 5:56 AM
> >
> > ACPI Device configuration often contain _CLS object to suppy
> > PCI-defined class code for the device. This patch introduces logic to
> > process the _CLS object.
> >
> > Acked-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> > Reviewed-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> > Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
> > ---
> > drivers/acpi/acpica/acutils.h | 3 ++
> > drivers/acpi/acpica/nsxfname.c | 21 ++++++++++--
> > drivers/acpi/acpica/utids.c | 73
> ++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 95 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/acpi/acpica/acutils.h
> > b/drivers/acpi/acpica/acutils.h index c2f03e8..2aef850 100644
> > --- a/drivers/acpi/acpica/acutils.h
> > +++ b/drivers/acpi/acpica/acutils.h
> > @@ -430,6 +430,9 @@ acpi_status
> > acpi_ut_execute_CID(struct acpi_namespace_node *device_node,
> > struct acpi_pnp_device_id_list ** return_cid_list);
> >
> > +acpi_status
> > +acpi_ut_execute_CLS(struct acpi_namespace_node *device_node,
> > + struct acpi_pnp_device_id **return_id);
> > /*
> > * utlock - reader/writer locks
> > */
> > diff --git a/drivers/acpi/acpica/nsxfname.c
> > b/drivers/acpi/acpica/nsxfname.c index d66c326..590ef06 100644
> > --- a/drivers/acpi/acpica/nsxfname.c
> > +++ b/drivers/acpi/acpica/nsxfname.c
> > @@ -276,11 +276,12 @@ acpi_get_object_info(acpi_handle handle,
> > struct acpi_pnp_device_id *hid = NULL;
> > struct acpi_pnp_device_id *uid = NULL;
> > struct acpi_pnp_device_id *sub = NULL;
> > + struct acpi_pnp_device_id *cls = NULL;
> > char *next_id_string;
> > acpi_object_type type;
> > acpi_name name;
> > u8 param_count = 0;
> > - u8 valid = 0;
> > + u16 valid = 0;
> > u32 info_size;
> > u32 i;
> > acpi_status status;
> > @@ -320,7 +321,7 @@ acpi_get_object_info(acpi_handle handle,
> > if ((type == ACPI_TYPE_DEVICE) || (type == ACPI_TYPE_PROCESSOR)) {
> > /*
> > * Get extra info for ACPI Device/Processor objects only:
> > - * Run the Device _HID, _UID, _SUB, and _CID methods.
> > + * Run the Device _HID, _UID, _SUB, _CID and _CLS methods.
> > *
> > * Note: none of these methods are required, so they may or
> may
> > * not be present for this device. The Info->Valid bitfield is
> used
> > @@ -351,6 +352,14 @@ acpi_get_object_info(acpi_handle handle,
> > valid |= ACPI_VALID_SUB;
> > }
> >
> > + /* Execute the Device._CLS method */
> > +
> > + status = acpi_ut_execute_CLS(node, &cls);
> > + if (ACPI_SUCCESS(status)) {
> > + info_size += cls->length;
> > + valid |= ACPI_VALID_CLS;
> > + }
> > +
> > /* Execute the Device._CID method */
> >
> > status = acpi_ut_execute_CID(node, &cid_list); @@ -468,6
> +477,11 @@
> > acpi_get_object_info(acpi_handle handle,
> > sub, next_id_string);
> > }
> >
> > + if (cls) {
> > + next_id_string = acpi_ns_copy_device_id(&info->cls,
> > + cls, next_id_string);
> > + }
> > +
> > if (cid_list) {
> > info->compatible_id_list.count = cid_list->count;
> > info->compatible_id_list.list_size = cid_list->list_size; @@ -
> 507,6
> > +521,9 @@ cleanup:
> > if (sub) {
> > ACPI_FREE(sub);
> > }
> > + if (cls) {
> > + ACPI_FREE(cls);
> > + }
> > if (cid_list) {
> > ACPI_FREE(cid_list);
> > }
> > diff --git a/drivers/acpi/acpica/utids.c b/drivers/acpi/acpica/utids.c
> > index 27431cf..9745065 100644
> > --- a/drivers/acpi/acpica/utids.c
> > +++ b/drivers/acpi/acpica/utids.c
> > @@ -416,3 +416,76 @@ cleanup:
> > acpi_ut_remove_reference(obj_desc);
> > return_ACPI_STATUS(status);
> > }
> > +
> > +/********************************************************************
> > +***********
> > + *
> > + * FUNCTION: acpi_ut_execute_CLS
> > + *
> > + * PARAMETERS: device_node - Node for the device
> > + * return_id - Where the string UID is returned
> > + *
> > + * RETURN: Status
> > + *
> > + * DESCRIPTION: Executes the _CLS control method that returns PCI-
> defined
> > + * class code of the device. The ACPI spec define _CLS as
> a
> > + * package with three integers. The returned string has
> format:
> > + *
> > + * "bbsspp"
> > + * where:
> > + * bb = Base-class code
> > + * ss = Sub-class code
> > + * pp = Programming Interface code
> > + *
> > +
> > +*********************************************************************
> > +*********/
> > +
> > +acpi_status
> > +acpi_ut_execute_CLS(struct acpi_namespace_node *device_node,
> > + struct acpi_pnp_device_id **return_id) {
> > + struct acpi_pnp_device_id *cls;
> > + union acpi_operand_object *obj_desc;
> > + union acpi_operand_object **cls_objects;
> > + acpi_status status;
> > +
> > + ACPI_FUNCTION_TRACE(ut_execute_CLS);
> > + status = acpi_ut_evaluate_object(device_node, METHOD_NAME__CLS,
> > + ACPI_BTYPE_PACKAGE, &obj_desc);
> > + if (ACPI_FAILURE(status))
> > + return_ACPI_STATUS(status);
> > +
> > + cls_objects = obj_desc->package.elements;
> > +
> > + if (obj_desc->common.type == ACPI_TYPE_PACKAGE &&
> > + obj_desc->package.count == 3 &&
> > + cls_objects[0]->common.type == ACPI_TYPE_INTEGER &&
> > + cls_objects[1]->common.type == ACPI_TYPE_INTEGER &&
> > + cls_objects[2]->common.type == ACPI_TYPE_INTEGER) {
> > +
> > + /* Allocate a buffer for the CLS */
> > + cls = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_pnp_device_id) +
> > + (acpi_size) 7);
> > + if (!cls) {
> > + status = AE_NO_MEMORY;
> > + goto cleanup;
> > + }
> > +
> > + cls->string =
> > + ACPI_ADD_PTR(char, cls, sizeof(struct
> acpi_pnp_device_id));
> > +
> > + sprintf(cls->string, "%02x%02x%02x",
> > + (u8)ACPI_TO_INTEGER(cls_objects[0]->integer.value),
> > + (u8)ACPI_TO_INTEGER(cls_objects[1]->integer.value),
> > + (u8)ACPI_TO_INTEGER(cls_objects[2]->integer.value));
> > + cls->length = 7;
> > + *return_id = cls;
> > + } else {
> > + status = AE_AML_OPERAND_TYPE;
> > + }
> > +
> > +cleanup:
> > +
> > + /* On exit, we must delete the return object */
> > +
> > + acpi_ut_remove_reference(obj_desc);
> > + return_ACPI_STATUS(status);
> > +}
> > --
> > 2.1.0

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