On Mon, Feb 27, 2017 at 03:12:26PM +0200, Marcel Apfelbaum wrote:
Add the missing osc method for pxb-pcie devices as APCI spec recommends,
see 6.2.10.3 OSC Implementation Example for PCI Host Bridge Devices, ACPI 5.0:
It is recommended that a machine with multiple host bridge devices
should report the same capabilities for all host bridges, and also
negotiate control of the features described in the Control Field in
the same way for all host bridges.
Reviewed-by: Igor Mammedov <address@hidden>
Signed-off-by: Marcel Apfelbaum <address@hidden>
---
Note to maintainer:
Please update ACPI test files.
V2 -> V3:
- Modified comment (Igor)
V1 -> V2:
Addressed Michael S. Tsirkin's comments:
- Added documentation to q35 osc function
- Made _osc serialized. I did not add compat property
since it seems guest OSs do not care anyway about the OSC
being serialized.
- Kept the SUPP field even if is not used and also
left both SUPP and CTRL out of the _osc because all
systems I checked and the ACPI spec keep them that way,
maybe is some kind of documentation contract.
Thanks,
Marcel
hw/i386/acpi-build.c | 41 +++++++++++++++++++++++++++++++++++------
1 file changed, 35 insertions(+), 6 deletions(-)
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 1c928ab..ad3f233 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -1796,7 +1796,7 @@ static void build_piix4_pci_hotplug(Aml *table)
aml_append(table, scope);
}
-static Aml *build_q35_osc_method(void)
+static void build_q35_osc_method(Aml *dev)
This does more than just build _OSC so please
give it a better name.
{
Aml *if_ctx;
Aml *if_ctx2;
@@ -1805,7 +1805,35 @@ static Aml *build_q35_osc_method(void)
Aml *a_cwd1 = aml_name("CDW1");
Aml *a_ctrl = aml_name("CTRL");
- method = aml_method("_OSC", 4, AML_NOTSERIALIZED);
+ /*
+ * Bits defined in the Support Field provide information
+ * regarding OS supported features.
+ *
+ * This field is not actually used and can be removed,
+ * however it appears even if unused on most DSDTs.
What does this mean? Our _OSC method uses these,
that's why we have them. How can you just remove them?
I think you mean we could remove the code writing to it.
I don't think keeping it around is justified.
Same applies to CTRL btw. We could use a local variable
instead.
+ *
+ * See:
+ * Table 6-148 Interpretation of _OSC Support Field,
+ * Passed in via the 2nd dword in Arg3, APCI 5.0
Why 5.0? This is not how we do it. Pls find the earliest spec version
that has this. 3.0?
+ */
+ aml_append(dev, aml_name_decl("SUPP", aml_int(0)));
+
+ /*
+ * Bits defined in the Control Field are used to submit
+ * request by the OS for control/handling of the associated feature
+ *
+ * See: Table 6-149 Interpretation of _OSC Control Field,
+ * Passed in via Arg3, ACPI 5.0
+ * Table 6-150 Interpretation of _OSC Control Field,
+ * Returned Value, APCI 5.0
+ */
+ aml_append(dev, aml_name_decl("CTRL", aml_int(0)));
+
+
+ /*
+ * 6.2.10 _OSC (Operating System Capabilities), APCI 5.0
+ */
Same here.
+ method = aml_method("_OSC", 4, AML_SERIALIZED);
aml_append(method, aml_create_dword_field(aml_arg(3), aml_int(0), "CDW1"));
if_ctx = aml_if(aml_equal(
@@ -1842,7 +1870,7 @@ static Aml *build_q35_osc_method(void)
aml_append(method, else_ctx);
aml_append(method, aml_return(aml_arg(3)));
- return method;
+ aml_append(dev, method);
If you drop SUPP and CTRL then you can keep it simple, right?
}
static void
@@ -1898,9 +1926,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
aml_append(dev, aml_name_decl("_CID", aml_eisaid("PNP0A03")));
aml_append(dev, aml_name_decl("_ADR", aml_int(0)));
aml_append(dev, aml_name_decl("_UID", aml_int(1)));
- aml_append(dev, aml_name_decl("SUPP", aml_int(0)));
- aml_append(dev, aml_name_decl("CTRL", aml_int(0)));
- aml_append(dev, build_q35_osc_method());
+ build_q35_osc_method(dev);
aml_append(sb_scope, dev);
aml_append(dsdt, sb_scope);
@@ -1964,6 +1990,9 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
aml_append(dev, aml_name_decl("_UID", aml_int(bus_num)));
aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A03")));
aml_append(dev, aml_name_decl("_BBN", aml_int(bus_num)));
+ if (pci_bus_is_express(bus)) {
+ build_q35_osc_method(dev);
+ }
if (numa_node != NUMA_NODE_UNASSIGNED) {
aml_append(dev, aml_name_decl("_PXM", aml_int(numa_node)));
--
2.5.5
so how about
--->
acpi: simplify _OSC
Our _OSC method has a bunch of unused code loading data
into external CTRL and SUPP fields which are then never
used. Drop this in favor of a single local variable.
Signed-off-by: Michael S. Tsirkin <address@hidden>
---
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index db04cf5..efbbfcb 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -1804,7 +1804,7 @@ static Aml *build_q35_osc_method(void)
Aml *else_ctx;
Aml *method;
Aml *a_cwd1 = aml_name("CDW1");
- Aml *a_ctrl = aml_name("CTRL");
+ Aml *a_ctrl = aml_local(0);
method = aml_method("_OSC", 4, AML_NOTSERIALIZED);
aml_append(method, aml_create_dword_field(aml_arg(3), aml_int(0), "CDW1"));
@@ -1814,7 +1814,6 @@ static Aml *build_q35_osc_method(void)
aml_append(if_ctx, aml_create_dword_field(aml_arg(3), aml_int(4), "CDW2"));
aml_append(if_ctx, aml_create_dword_field(aml_arg(3), aml_int(8), "CDW3"));
- aml_append(if_ctx, aml_store(aml_name("CDW2"), aml_name("SUPP")));
aml_append(if_ctx, aml_store(aml_name("CDW3"), a_ctrl));
/*
@@ -1899,8 +1898,6 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
aml_append(dev, aml_name_decl("_CID", aml_eisaid("PNP0A03")));
aml_append(dev, aml_name_decl("_ADR", aml_int(0)));
aml_append(dev, aml_name_decl("_UID", aml_int(1)));
- aml_append(dev, aml_name_decl("SUPP", aml_int(0)));
- aml_append(dev, aml_name_decl("CTRL", aml_int(0)));
aml_append(dev, build_q35_osc_method());
aml_append(sb_scope, dev);
aml_append(dsdt, sb_scope);