[PATCH 1/1] hw/i386/acpi-build: add OSHP method support for SHPC driver load

[Shiyuan Gao via]

SHPC driver will be loaded fail in i440fx platform, the dmesg shows
that OS cannot get control of SHPC hotplug and hotplug device to
the PCI bridge will fail when we use SHPC Native type:

  [3.336059] shpchp 0000:00:03.0: Requesting control of SHPC hotplug via OSHP 
(\_SB_.PCI0.S28_)
  [3.337408] shpchp 0000:00:03.0: Requesting control of SHPC hotplug via OSHP 
(\_SB_.PCI0)
  [3.338710] shpchp 0000:00:03.0: Cannot get control of SHPC hotplug

Add OSHP method support for SHPC driver load, the hotplug device to the PCI 
bridge will
success when we use SHPC Native type.

  [1.703975] shpchp 0000:00:03.0: Requesting control of SHPC hotplug via OSHP 
(\_SB_.PCI0.S18_)
  [1.704934] shpchp 0000:00:03.0: Requesting control of SHPC hotplug via OSHP 
(\_SB_.PCI0)
  [1.705855] shpchp 0000:00:03.0: Gained control of SHPC hotplug (\_SB_.PCI0)
  [1.707054] shpchp 0000:00:03.0: HPC vendor_id 1b36 device_id 1 ss_vid 0 
ss_did 0

According to the acpi_pcihp, the OSHP method don't need parameter and return 
value now.

  shpc_probe
    --> acpi_get_hp_hw_control_from_firmware
      --> acpi_run_oshp
        --> status = acpi_evaluate_object(handle, METHOD_NAME_OSHP, NULL, NULL);

Signed-off-by: Shiyuan Gao <gaoshiy...@baidu.com>
---
 hw/i386/acpi-build.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index f4e366f64f..79622e6939 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -1412,6 +1412,18 @@ static void build_acpi0017(Aml *table)
     aml_append(table, scope);
 }
 
+static Aml *build_oshp_method(void)
+{
+    Aml *method;
+
+    /*
+     * Request control of SHPC hotplug via OSHP method,
+     * no need parameter and return value in acpi_pcihp.
+     */
+    method = aml_method("OSHP", 0, AML_NOTSERIALIZED);
+    return method;
+}
+
 static void
 build_dsdt(GArray *table_data, BIOSLinker *linker,
            AcpiPmInfo *pm, AcpiMiscInfo *misc,
@@ -1452,6 +1464,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
         aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A03")));
         aml_append(dev, aml_name_decl("_UID", aml_int(pcmc->pci_root_uid)));
         aml_append(dev, aml_pci_edsm());
+        aml_append(dev, build_oshp_method());
         aml_append(sb_scope, dev);
         aml_append(dsdt, sb_scope);
 
@@ -1586,6 +1599,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
                 aml_append(dev, build_q35_osc_method(true));
             } else {
                 aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A03")));
+                aml_append(dev, build_oshp_method());
             }
 
             if (numa_node != NUMA_NODE_UNASSIGNED) {
-- 
2.27.0