>
> On Fri, 2008-10-24 at 13:42 -0500, John Keller wrote:
> > >
> > > 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.
> Great! I too was bringing up an upcoming platform that is our first
> platform to use "Device" declarations and got bit because of the current
> logic.
>
> So, based on the ACPI specification, my patch, and replies: do you agree
> that for "Device" statement declarations the platform should have the
> "Device" statement's '_UID' child object value match the corresponding
> MADT (or_MAT) table Local SAPIC entry's "ACPI Processor UID Value" to
> end up with the correct ID:EID?
Agreed.
> The fact that the platform's firmware
> (ACPI namespace) needed to also match the Local SAPIC entry's "ACPI
> Processor ID" was really not necessary (this was the broken part of the
> existing implementation) was really unnecessary and is really a
> misunderstanding or misinterpretation of the specification?
I suspect I agree with you on this too.
The two issues for me were:
- The Device UID and Local SAPIC entry's UID values needed
to also match the Local SAPIC entry's
((LocalSAPIC ID << 8) | LocalSAPIC EID).
- The map_lsapic_id() code was first trying to match the
acpi_id with the Local SAPIC entry's "ACPI Processor UID Value"
even if the acpi_id was obtained from the "Device"
statement's '_UID'.
>
> Let me know how this area goes for you with my patches - hopefully they
> help solve your issues!
OK, though I'm still in the very early phases of all this.
>
> Thanks for your information and please keep corresponding until we get
> this solved to all of our satisfaction,
>
> Myron
> >
> > 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;
> > > > >
> > > > >
> > > > > --
> > > > > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> > > > > 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
> > >
> > >
> >
> --
> Myron Stowe HP Open Source & Linux Org
>
>
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