[PULL 44/55] x86: acpi: _DSM: use Package to pass parameters

[Michael S. Tsirkin]

From: Igor Mammedov <imammedo@redhat.com>

Numer of possible arguments to pass to a method is limited
in ACPI. The following patches will need to pass over more
parameters to PDSM method, will hit that limit.

Prepare for this by passing structure (Package) to method,
which let us workaround arguments limitation.
Pass to PDSM all standard arguments of _DSM as is, and
pack custom parameters into Package that is passed as
the last argument to PDSM.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20220701133515.137890-7-imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/i386/acpi-build.c | 40 +++++++++++++++++++++++++++-------------
 1 file changed, 27 insertions(+), 13 deletions(-)

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 6d02eed12c..a19900c4e4 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -431,11 +431,17 @@ static void build_append_pci_bus_devices(Aml 
*parent_scope, PCIBus *bus,
                 );
                 aml_append(dev, method);
                 method = aml_method("_DSM", 4, AML_SERIALIZED);
-                aml_append(method,
-                    aml_return(aml_call6("PDSM", aml_arg(0), aml_arg(1),
-                                         aml_arg(2), aml_arg(3),
-                                         aml_name("BSEL"), aml_name("_SUN")))
-                );
+                {
+                    Aml *params = aml_local(0);
+                    Aml *pkg = aml_package(2);
+                    aml_append(pkg, aml_name("BSEL"));
+                    aml_append(pkg, aml_name("_SUN"));
+                    aml_append(method, aml_store(pkg, params));
+                    aml_append(method,
+                        aml_return(aml_call5("PDSM", aml_arg(0), aml_arg(1),
+                                             aml_arg(2), aml_arg(3), params))
+                    );
+                }
                 aml_append(dev, method);
                 aml_append(parent_scope, dev);
 
@@ -480,10 +486,17 @@ static void build_append_pci_bus_devices(Aml 
*parent_scope, PCIBus *bus,
              */
             aml_append(dev, aml_name_decl("ASUN", aml_int(slot)));
             method = aml_method("_DSM", 4, AML_SERIALIZED);
-            aml_append(method, aml_return(
-                aml_call6("PDSM", aml_arg(0), aml_arg(1), aml_arg(2),
-                          aml_arg(3), aml_name("BSEL"), aml_name("ASUN"))
-            ));
+            {
+                Aml *params = aml_local(0);
+                Aml *pkg = aml_package(2);
+                aml_append(pkg, aml_name("BSEL"));
+                aml_append(pkg, aml_name("ASUN"));
+                aml_append(method, aml_store(pkg, params));
+                aml_append(method, aml_return(
+                    aml_call5("PDSM", aml_arg(0), aml_arg(1), aml_arg(2),
+                              aml_arg(3), params)
+                ));
+            }
             aml_append(dev, method);
         }
 
@@ -580,12 +593,13 @@ Aml *aml_pci_device_dsm(void)
     Aml *acpi_index = aml_local(2);
     Aml *zero = aml_int(0);
     Aml *one = aml_int(1);
-    Aml *bnum = aml_arg(4);
     Aml *func = aml_arg(2);
     Aml *rev = aml_arg(1);
-    Aml *sunum = aml_arg(5);
+    Aml *params = aml_arg(4);
+    Aml *bnum = aml_derefof(aml_index(params, aml_int(0)));
+    Aml *sunum = aml_derefof(aml_index(params, aml_int(1)));
 
-    method = aml_method("PDSM", 6, AML_SERIALIZED);
+    method = aml_method("PDSM", 5, AML_SERIALIZED);
 
     /* get supported functions */
     ifctx = aml_if(aml_equal(func, zero));
@@ -662,10 +676,10 @@ Aml *aml_pci_device_dsm(void)
         * update acpi-index to actual value
         */
        aml_append(ifctx, aml_store(acpi_index, aml_index(ret, zero)));
+       aml_append(ifctx, aml_return(ret));
     }
 
     aml_append(method, ifctx);
-    aml_append(method, aml_return(ret));
     return method;
 }
 
-- 
MST