Re: [Qemu-devel] [PATCH v4 for-2.3 11/25] hw/apci: add _PRT method for extra PCI root busses

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

On Tue, Mar 10, 2015 at 07:26:13PM +0200, Marcel Apfelbaum wrote:
> On 03/10/2015 07:07 PM, Michael S. Tsirkin wrote:
> >On Sun, Mar 08, 2015 at 01:16:13PM +0200, Marcel Apfelbaum wrote:
> >>Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
> >>---
> >>  hw/i386/acpi-build.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> >>  1 file changed, 65 insertions(+)
> >>
> >>diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> >>index e5709e8..e7a1a36 100644
> >>--- a/hw/i386/acpi-build.c
> >>+++ b/hw/i386/acpi-build.c
> >>@@ -664,6 +664,70 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus,
> >>      aml_append(parent_scope, method);
> >>  }
> >>
> >>+static Aml *build_link(Aml *lnk, Aml *lnk_pkg, const char *link_name, int idx)
> >
> >Pls document arguments, and generally make this function
> >more readable.
> I'll think of something
> 
> >
> >>+{
> >>+    Aml *if_ctx, *pkg;
> >>+
> >>+    if_ctx = aml_if(aml_equal(lnk, aml_int(idx)));
> >>+    pkg = aml_package(4);
> >
> >These assignments can be part of declarations.
> OK
> 
> >
> >>+    aml_append(pkg, aml_int(0));
> >>+    aml_append(pkg, aml_int(0));
> >>+    aml_append(pkg, aml_name(link_name, ""));
> >
> >this sould be aml_name(link_name) I think?
> It doesn't work without the "" agument, works only for literals.
> If you have any idea how to make it work, I'll be glad to change it.

So use "%s" format then.

> >
> >>+    aml_append(pkg, aml_int(0));
> >>+    aml_append(if_ctx, aml_store(pkg, lnk_pkg));
> >>+
> >>+    return if_ctx;
> >>+}
> >>+
> >>+static Aml *build_prt(void)
> >>+{
> >>+    Aml *method, *while_ctx, *pin, *slot, *lnk, *pkg, *res;
> >>+
> >>+    method = aml_method("_PRT", 0);
> >>+    res = aml_local(0);
> >>+    pin = aml_local(1);
> >>+    slot = aml_local(2);
> >>+    lnk = aml_local(3);
> >>+    pkg = aml_local(4);
> >>+
> >>+    aml_append(method, aml_store(aml_package(128), res));
> >>+    aml_append(method, aml_store(aml_int(0), pin));
> >>+
> >>+    /* while (pin < 128) */
> >>+    while_ctx = aml_while(aml_lless(pin, aml_int(128)));
> >>+    {
> >>+        /* slot = pin >> 2 */
> >>+        aml_append(while_ctx,
> >>+                   aml_store(aml_shiftright(pin, aml_int(2)), slot));
> >>+        /* lnk = (slot + pin) & 3 */
> >>+        aml_append(while_ctx,
> >>+                   aml_store(aml_and(aml_add(pin, slot), aml_int(3)), lnk));
> >>+
> >>+        /* pkg[2] = "LNK[A|B|C|D]", selection based on lnk % 3  */
> >
> >in fact pkg here is not same as pkg above, is it?
> The same, but I can move the declaration to the while block.
> 
> Thanks,
> Marcel
> 
> >
> >>+        aml_append(while_ctx, build_link(lnk, pkg, "LNKD", 0));
> >>+        aml_append(while_ctx, build_link(lnk, pkg, "LNKA", 1));
> >>+        aml_append(while_ctx, build_link(lnk, pkg, "LNKB", 2));
> >>+        aml_append(while_ctx, build_link(lnk, pkg, "LNKC", 3));
> >>+
> >>+        /* pkg[0] = 0x[slot]FFFF */
> >>+        aml_append(while_ctx,
> >>+            aml_store(aml_or(aml_shiftleft(slot, aml_int(16)), aml_int(0xFFFF)),
> >>+                      aml_index(pkg, aml_int(0))));
> >>+        /* pkg[1] = pin & 3 */
> >>+        aml_append(while_ctx,
> >>+            aml_store(aml_and(pin, aml_int(3)), aml_index(pkg, aml_int(1))));
> >>+        /* res[pin] = pkg */
> >>+        aml_append(while_ctx, aml_store(pkg, aml_index(res, pin)));
> >>+        /* pin++ */
> >>+        aml_append(while_ctx, aml_increment(pin));
> >>+    }
> >>+    aml_append(method, while_ctx);
> >>+    /* return res*/
> >>+    aml_append(method, aml_return(res));
> >>+
> >>+    return method;
> >>+}
> >>+
> >>  static void
> >>  build_ssdt(GArray *table_data, GArray *linker,
> >>             AcpiCpuInfo *cpu, AcpiPmInfo *pm, AcpiMiscInfo *misc,
> >>@@ -708,6 +772,7 @@ 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