Re: [Qemu-devel] [PATCH v3 for-2.3 10/24] hw/apci: add _PRT method for extra PCI root busses

["Michael S. Tsirkin" <mst@redhat.com>]

On Sun, Mar 08, 2015 at 01:04:07PM +0200, Marcel Apfelbaum wrote:
> On 03/08/2015 12:46 PM, Michael S. Tsirkin wrote:
> >On Thu, Mar 05, 2015 at 04:55:08PM +0200, Marcel Apfelbaum wrote:
> >>Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
> >
> >some ideas for cleaning this up.
> >there's more here btw.
> >
> >>---
> >>  hw/i386/acpi-build.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> >>  1 file changed, 78 insertions(+)
> >>
> >>diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> >>index e5709e8..f0401d2 100644
> >>--- a/hw/i386/acpi-build.c
> >>+++ b/hw/i386/acpi-build.c
> >>@@ -664,6 +664,83 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus,
> >>      aml_append(parent_scope, method);
> >>  }
> >>
> >>+static Aml *build_prt(void)
> >>+{
> >>+    Aml *method, *pkg, *if_ctx, *while_ctx;
> >>+
> >>+    method = aml_method("_PRT", 0);
> >>+
> >>+    aml_append(method, aml_store(aml_package(128), aml_local(0)));
> >>+    aml_append(method, aml_store(aml_int(0), aml_local(1)));
> >>+    while_ctx = aml_while(aml_lless(aml_local(1), aml_int(128)));
> >>+    {
> >>+        aml_append(while_ctx,
> >>+            aml_store(aml_shiftright(aml_local(1), aml_int(2)), aml_local(2)));
> >>+        aml_append(while_ctx,
> >>+            aml_store(aml_and(aml_add(aml_local(1), aml_local(2)), aml_int(3)),
> >>+                      aml_local(3)));
> >
> >
> >As an example, you can have
> >
> >Aml *i = aml_local(1);
> >Aml *mask = aml_local(2);
> Hi Michael,
> 
> Thank you for the tip, the implementation is ready
> and I'll submit it right away.

So, one thing that's problematic here is that
expected files need to be examined manually.
How about a three-stage approach:

1. move _PRT out from DSDT - e.g. to a separate ssdt,
   update expected files.
   One way to do this is to first revert
	commit 4ec8d2b3f54dd1dcd9e2a80e529feff4e2603288
	Author: Igor Mammedov <imammedo@redhat.com>
	    pc: acpi-build: drop remaining ssdt_misc template
2. rewrite  the new SSDT in C,
   produce an otherwise identical code.
   make check will catch errors
3. reuse code from (2) for extra roots.


> BTW, I found a bug in aml_equal implementation during re-testing,
> so it was worth it!
> 
> Thanks,
> Marcel
> 
> >
> >
> >>+
> >>+        if_ctx = aml_if(aml_equal(aml_local(3), aml_int(0)));
> >>+        {
> >>+            pkg = aml_package(4);
> >
> >Make pkg local here?
> >
> >>+            aml_append(pkg, aml_int(0));
> >>+            aml_append(pkg, aml_int(0));
> >>+            aml_append(pkg, aml_name("LNKD"));
> >>+            aml_append(pkg, aml_int(0));
> >>+            aml_append(if_ctx, aml_store(pkg, aml_local(4)));
> >>+        }
> >>+        aml_append(while_ctx, if_ctx);
> >>+
> >>+        if_ctx = aml_if(aml_equal(aml_local(3), aml_int(1)));
> >>+        {
> >>+            pkg = aml_package(4);
> >>+            aml_append(pkg, aml_int(0));
> >>+            aml_append(pkg, aml_int(0));
> >>+            aml_append(pkg, aml_name("LNKA"));
> >>+            aml_append(pkg, aml_int(0));
> >>+            aml_append(if_ctx, aml_store(pkg, aml_local(4)));
> >>+        }
> >>+        aml_append(while_ctx, if_ctx);
> >>+
> >>+        if_ctx = aml_if(aml_equal(aml_local(3), aml_int(2)));
> >>+        {
> >>+            pkg = aml_package(4);
> >>+            aml_append(pkg, aml_int(0));
> >>+            aml_append(pkg, aml_int(0));
> >>+            aml_append(pkg, aml_name("LNKB"));
> >>+            aml_append(pkg, aml_int(0));
> >>+            aml_append(if_ctx, aml_store(pkg, aml_local(4)));
> >>+        }
> >>+        aml_append(while_ctx, if_ctx);
> >>+
> >>+        if_ctx = aml_if(aml_equal(aml_local(3), aml_int(3)));
> >>+        {
> >>+            pkg = aml_package(4);
> >>+            aml_append(pkg, aml_int(0));
> >>+            aml_append(pkg, aml_int(0));
> >>+            aml_append(pkg, aml_name("LNKC"));
> >>+            aml_append(pkg, aml_int(0));
> >>+            aml_append(if_ctx, aml_store(pkg, aml_local(4)));
> >>+        }
> >>+        aml_append(while_ctx, if_ctx);
> >>+
> >>+        aml_append(while_ctx,
> >>+            aml_store(aml_or(aml_shiftleft(aml_local(2), aml_int(16)),
> >>+                             aml_int(0xFFFF)),
> >>+                      aml_index(aml_local(4), aml_int(0))));
> >>+        aml_append(while_ctx,
> >>+            aml_store(aml_and(aml_local(1), aml_int(3)),
> >>+                      aml_index(aml_local(4), aml_int(1))));
> >>+        aml_append(while_ctx,
> >>+            aml_store(aml_local(4), aml_index(aml_local(0), aml_local(1))));
> >>+        aml_append(while_ctx, aml_increment(aml_local(1)));
> >>+    }
> >>+    aml_append(method, while_ctx);
> >>+    aml_append(method, aml_return(aml_local(0)));
> >>+
> >>+    return method;
> >>+}
> >>+
> >>  static void
> >>  build_ssdt(GArray *table_data, GArray *linker,
> >>             AcpiCpuInfo *cpu, AcpiPmInfo *pm, AcpiMiscInfo *misc,
> >>@@ -708,6 +785,7 @@ build_ssdt(GArray *table_data, GArray *linker,
> >>              aml_append(dev, aml_name_decl("_HID", aml_string("PNP0A03")));
> >>              aml_append(dev,
> >>                  aml_name_decl("_BBN", aml_int((uint8_t)bus_info->bus)));
> >>+            aml_append(dev, build_prt());
> >>              aml_append(scope, dev);
> >>              aml_append(ssdt, scope);
> >>          }
> >>--
> >>2.1.0