>
> On Fri, 2008-10-24 at 10:56 -0500, John Keller wrote:
> > >
> > >
> > > Associating a Local SAPIC with a processor object is dependent upon the
> > > processor object's definition type. CPUs declared as "Processor" should use
> > > the Local SAPIC's 'processor_id', and CPUs declared as "Device" should use the
> > > 'uid' (see section 5.2.11.13 - Local SAPIC Structure; "Advanced Configuration
> > > and Power Interface Specification", Revision 3.0b).
> > >
> > > This patch changes the lsapic mapping logic to rely on the distinction of
> > > how the processor object was declared - the mapping can't just try both types
> > > of matches irregardless of declaration type and rely on one failing as is
> > > currently being done.
> > >
> > > Signed-off-by: Myron Stowe <myron.stowe@xxxxxx>
> > > CC: Alexey Starikovskiy <aystarik@xxxxxxxxx>
> > >
> > > ---
> > > drivers/acpi/processor_core.c | 64 +++++++++++++++++++++++-------------------
> > > 1 file changed, 36 insertions(+), 28 deletions(-)
> > >
> > > Index: linux-2.6/drivers/acpi/processor_core.c
> > > ===================================================================
> > > --- linux-2.6.orig/drivers/acpi/processor_core.c 2008-10-21 13:12:13.000000000 -0600
> > > +++ linux-2.6/drivers/acpi/processor_core.c 2008-10-22 12:12:11.000000000 -0600
> > > @@ -410,7 +410,7 @@ static int acpi_processor_remove_fs(stru
> > > /* Use the acpiid in MADT to map cpus in case of SMP */
> > >
> > > #ifndef CONFIG_SMP
> > > -static int get_cpu_id(acpi_handle handle, u32 acpi_id) {return -1;}
> > > +static int get_cpu_id(acpi_handle handle, int type, u32 acpi_id) { return -1; }
> > > #else
> > >
> > > static struct acpi_table_madt *madt;
> > > @@ -429,27 +429,33 @@ static int map_lapic_id(struct acpi_subt
> > > }
> > >
> > > static int map_lsapic_id(struct acpi_subtable_header *entry,
> > > - u32 acpi_id, int *apic_id)
> > > + int device_declaration, u32 acpi_id, int *apic_id)
> > > {
> > > struct acpi_madt_local_sapic *lsapic =
> > > (struct acpi_madt_local_sapic *)entry;
> > > + u32 tmp = (lsapic->id << 8) | lsapic->eid;
> > > +
> > > /* Only check enabled APICs*/
> > > - if (lsapic->lapic_flags & ACPI_MADT_ENABLED) {
> > > - /* First check against id */
> > > - if (lsapic->processor_id == acpi_id) {
> > > - *apic_id = (lsapic->id << 8) | lsapic->eid;
> > > - return 1;
> > > - /* Check against optional uid */
> > > - } else if (entry->length >= 16 &&
> > > - lsapic->uid == acpi_id) {
> > > - *apic_id = lsapic->uid;
> > > - return 1;
> > > - }
> > > - }
> > > + if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))
> > > + return 0;
> > > +
> > > + /* Device statement declaration type */
> > > + if (device_declaration) {
> > > + if (entry->length < 16)
> > > + printk(KERN_ERR PREFIX "Invalid Local SAPIC structure corresponding to Device statement processor with SAPIC ID %#x\n", tmp);
> > > + else if (lsapic->uid == acpi_id)
> > > + goto found;
> > > + /* Processor statement declaration type */
> > > + } else if (lsapic->processor_id == acpi_id)
> > > + goto found;
> > > +
> > > return 0;
> > > +found:
> > > + *apic_id = tmp;
> > > + return 1;
> > > }
> >
> > If I read this right, lsapic->uid and acpi_id (Processor Device _UID)
> > no longer need to equal (lsapic->id << 8) | lsapic->eid), as now 'tmp'
> > will be the value returned.
> > Is this correct?
> Yes.
> > I don't know of a problem with this, just making sure I understand this.
> Yeah - there were problems ;)
>
> What I think you might be getting at is that there are two possible
> explanations for why this logic has been working till now:
> * There have been platforms using the "Device" declaration but the
> firmware must have went through great pains to ensure that all
> these fields involved *artificially* matched (which is what I
> believe you are alluding to and I believe is a misunderstanding
> of the spec if that was the case).
Yes, this is what motivated my questions.
As part of testing firmware support for an upcoming platform, where
"Device" declarations will be used, I quickly learned that currently
all these fields need to match.
Thanks for the reply,
John
> - or -
> * There have been no platforms using the "Device" declaration and
> so map_lsapic_id()'s 'if (lsapic->processor_id == acpi_id)' was
> always succeeding and the 'else if ...' path was never taken. I
> tend to believe this has been the case (but that is pure
> assumption which means little).
> >
> > Glad to see this change, as I had concerns of map_lsapic_id() first
> > trying to match against lsapic->processor_id, and possibly ignoring
> > lsapic->uid.
> Yes - the logic as it currently is, is not specific/strict enough. What
> I seem to be failing to be able to express well enough earlier in the
> thread is basically this:
>
> CPUs declared in namespace using a "Processor" statement must
> use the "Processor" statement's 'ProcessorID' field to match to
> the corresponding Local SAPIC entry (matching the Local SAPIC
> entries 'ACPIProcessorID' field). Whether or not the
> "Processor" statement has a '_UID' child object has no bearing
> with respect to the mapping.
>
> Conversely, CPUs declared in namespace using a "Device"
> statement must use the "Device" statement's '_UID' child object
> field to match to the corresponding Local SAPIC entry (matching
> the Local SAPIC entries '_UID' field).
>
> At least this is how we are interpreting section 5.2.11.13 "Local SAPIC
> Structure" of the specification (specifically see the Description for
> both ACPI Processor ID and ACPI Processor UID Value).
>
> Thanks for your query!
> Myron
> >
> > Thanks,
> > John
> >
> >
> >
> > >
> > > -static int map_madt_entry(u32 acpi_id)
> > > +static int map_madt_entry(int type, u32 acpi_id)
> > > {
> > > unsigned long madt_end, entry;
> > > int apic_id = -1;
> > > @@ -470,7 +476,7 @@ static int map_madt_entry(u32 acpi_id)
> > > if (map_lapic_id(header, acpi_id, &apic_id))
> > > break;
> > > } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
> > > - if (map_lsapic_id(header, acpi_id, &apic_id))
> > > + if (map_lsapic_id(header, type, acpi_id, &apic_id))
> > > break;
> > > }
> > > entry += header->length;
> > > @@ -478,7 +484,7 @@ static int map_madt_entry(u32 acpi_id)
> > > return apic_id;
> > > }
> > >
> > > -static int map_mat_entry(acpi_handle handle, u32 acpi_id)
> > > +static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
> > > {
> > > struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
> > > union acpi_object *obj;
> > > @@ -501,7 +507,7 @@ static int map_mat_entry(acpi_handle han
> > > if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
> > > map_lapic_id(header, acpi_id, &apic_id);
> > > } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
> > > - map_lsapic_id(header, acpi_id, &apic_id);
> > > + map_lsapic_id(header, type, acpi_id, &apic_id);
> > > }
> > >
> > > exit:
> > > @@ -510,14 +516,14 @@ exit:
> > > return apic_id;
> > > }
> > >
> > > -static int get_cpu_id(acpi_handle handle, u32 acpi_id)
> > > +static int get_cpu_id(acpi_handle handle, int type, u32 acpi_id)
> > > {
> > > int i;
> > > int apic_id = -1;
> > >
> > > - apic_id = map_mat_entry(handle, acpi_id);
> > > + apic_id = map_mat_entry(handle, type, acpi_id);
> > > if (apic_id == -1)
> > > - apic_id = map_madt_entry(acpi_id);
> > > + apic_id = map_madt_entry(type, acpi_id);
> > > if (apic_id == -1)
> > > return apic_id;
> > >
> > > @@ -533,15 +539,16 @@ static int get_cpu_id(acpi_handle handle
> > > Driver Interface
> > > -------------------------------------------------------------------------- */
> > >
> > > -static int acpi_processor_get_info(struct acpi_processor *pr, unsigned has_uid)
> > > +static int acpi_processor_get_info(struct acpi_device *device)
> > > {
> > > acpi_status status = 0;
> > > union acpi_object object = { 0 };
> > > struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
> > > - int cpu_index;
> > > + struct acpi_processor *pr;
> > > + int cpu_index, device_declaration = 0;
> > > static int cpu0_initialized;
> > >
> > > -
> > > + pr = acpi_driver_data(device);
> > > if (!pr)
> > > return -EINVAL;
> > >
> > > @@ -562,8 +569,8 @@ static int acpi_processor_get_info(struc
> > > ACPI_DEBUG_PRINT((ACPI_DB_INFO,
> > > "No bus mastering arbitration control\n"));
> > >
> > > - /* Check if it is a Device with HID and UID */
> > > - if (has_uid) {
> > > + /* Check if it is a Device statement declaration with HID and UID */
> > > + if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_HID)) {
> > > unsigned long value;
> > > status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
> > > NULL, &value);
> > > @@ -571,6 +578,7 @@ static int acpi_processor_get_info(struc
> > > printk(KERN_ERR PREFIX "Evaluating processor _UID\n");
> > > return -ENODEV;
> > > }
> > > + device_declaration = 1;
> > > pr->acpi_id = value;
> > > } else {
> > > /*
> > > @@ -590,7 +598,7 @@ static int acpi_processor_get_info(struc
> > > */
> > > pr->acpi_id = object.processor.proc_id;
> > > }
> > > - cpu_index = get_cpu_id(pr->handle, pr->acpi_id);
> > > + cpu_index = get_cpu_id(pr->handle, device_declaration, pr->acpi_id);
> > >
> > > /* Handle UP system running SMP kernel, with no LAPIC in MADT */
> > > if (!cpu0_initialized && (cpu_index == -1) &&
> > > @@ -662,7 +670,7 @@ static int __cpuinit acpi_processor_star
> > >
> > > pr = acpi_driver_data(device);
> > >
> > > - result = acpi_processor_get_info(pr, device->flags.unique_id);
> > > + result = acpi_processor_get_info(device);
> > > if (result) {
> > > /* Processor is physically not present */
> > > return 0;
> > >
> > >
> > > --
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> > > the body of a message to majordomo@xxxxxxxxxxxxxxx
> > > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > >
> >
> --
> Myron Stowe HP Open Source & Linux Org
>
>
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