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 05:22:43PM +0200, Marcel Apfelbaum wrote:
> On 03/08/2015 04:47 PM, Michael S. Tsirkin wrote:
> >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.
> Only if pxb-device is added, otherwise they remain the same.
> So by default, make check remains unchanged.
> >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.
> 
> I am aware of this and I was planning to do that on top of this series.
> Four reasons for this:
>  1. As stated before, it does not affect make check because this code
>     affects the ACPI table only if pxb-device is present.
>  2. The _PRT is not *exactly* the same, bus 0's _PRT has an extra "if" for
>     the power-management device than needs needs SCI
>  3. The series is already big, I prefer attacking this as a new enhancement:
>     "Dynamically create bus 0 _PRT"
>  4. QEMU 2.3 is approaching, I don't want o diverge now
> 
> 
> Thanks,
> Marcel

Meanwhile 2.3 will have two almost identical copies of _PRT?
I don't think that's a good idea.

> >
> >
> >>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