[PATCH edk2-platforms 2/5] Silicon/SynQuacer: tweak PCI I/O windows for ACPI/Linux support

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

ACPI is not able to describe PCI resource windows that involve both type
and address translation (i.e., for I/O windows on architectures that do
not support port I/O natively), and so the ACPI/Linux code has a hard
time performing the resource allocation in such cases. For instance, the
secondary I/O window we implement on SynQuacer:

   I/O  0x10000 ... 0x1ffff -> 0x77f00000

is misinterpreted by Linux, and results in the MMIO range starting at
0x77f10000 to be mapped for I/O port access to this range.

This can be mitigated by using the same PCI range for I/O port access
on both RCs., i.e., 0x0 ... 0xffff. This configuration can be represented
using both DT and ACPI, and will work as expected in Linux, since it only
involves type translation and not address translation.

However, there is a downside: EDK2 does not cope with I/O address
translation in the generic PCI host bridge driver, and so it does
not allow two regions 0x0 ... 0xffff to be configured.

So in addition, let's reduce the windows declared to the UEFI PCI layer
to 0x0 ... 0x7fff and 0x8000 ... 0xffff. This leaves ample room for I/O
BARs (which nobody uses anymore anyway), and allows UEFI and the OS to
share the same static configuration of the PCIe BAR windows.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
Heyi Gui is currently implementing support for address translation in
the generic PCI host bridge driver, so hopefully, limiting the I/O
ranges in UEFI is something we can revert shortly.

 Silicon/Socionext/SynQuacer/DeviceTree/SynQuacer.dtsi                                                |  2 +-
 Silicon/Socionext/SynQuacer/Include/Platform/Pcie.h                                                  | 18 +++++++++++-------
 Silicon/Socionext/SynQuacer/Library/SynQuacerPciHostBridgeLib/SynQuacerPciHostBridgeLibConstructor.c |  4 ++--
 3 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/Silicon/Socionext/SynQuacer/DeviceTree/SynQuacer.dtsi b/Silicon/Socionext/SynQuacer/DeviceTree/SynQuacer.dtsi
index 05d1673a5c2b..6eb5fd9430cb 100644
--- a/Silicon/Socionext/SynQuacer/DeviceTree/SynQuacer.dtsi
+++ b/Silicon/Socionext/SynQuacer/DeviceTree/SynQuacer.dtsi
@@ -483,7 +483,7 @@
         bus-range = <0x0 0x7e>;
         #address-cells = <3>;
         #size-cells = <2>;
-        ranges = <0x1000000 0x00 0x00010000 0x00 0x77f00000 0x0 0x00010000>,
+        ranges = <0x1000000 0x00 0x00000000 0x00 0x77f00000 0x0 0x00010000>,
                  <0x2000000 0x00 0x78000000 0x00 0x78000000 0x0 0x08000000>,
                  <0x3000000 0x3f 0x00000000 0x3f 0x00000000 0x1 0x00000000>;
 
diff --git a/Silicon/Socionext/SynQuacer/Include/Platform/Pcie.h b/Silicon/Socionext/SynQuacer/Include/Platform/Pcie.h
index 2d3d5cd91be0..ee57377ac3be 100644
--- a/Silicon/Socionext/SynQuacer/Include/Platform/Pcie.h
+++ b/Silicon/Socionext/SynQuacer/Include/Platform/Pcie.h
@@ -23,12 +23,12 @@
 
 #define SYNQUACER_PCI_SEG0_BUSNUM_MIN       0x0
 #define SYNQUACER_PCI_SEG0_BUSNUM_MAX       0x7e
+#define SYNQUACER_PCI_SEG0_BUSNUM_RANGE     0x7f
 
 #define SYNQUACER_PCI_SEG0_PORTIO_MIN       0x0
-#define SYNQUACER_PCI_SEG0_PORTIO_MAX       0xffff
-#define SYNQUACER_PCI_SEG0_PORTIO_SIZE      0x10000
+#define SYNQUACER_PCI_SEG0_PORTIO_MAX       0x7fff
 #define SYNQUACER_PCI_SEG0_PORTIO_MEMBASE   0x67f00000
-#define SYNQUACER_PCI_SEG0_PORTIO_MEMSIZE   SYNQUACER_PCI_SEG0_PORTIO_SIZE
+#define SYNQUACER_PCI_SEG0_PORTIO_MEMSIZE   0x10000
 
 #define SYNQUACER_PCI_SEG0_MMIO32_MIN       0x68000000
 #define SYNQUACER_PCI_SEG0_MMIO32_MAX       0x6fffffff
@@ -45,12 +45,12 @@
 
 #define SYNQUACER_PCI_SEG1_BUSNUM_MIN       0x0
 #define SYNQUACER_PCI_SEG1_BUSNUM_MAX       0x7e
+#define SYNQUACER_PCI_SEG1_BUSNUM_RANGE     0x7f
 
-#define SYNQUACER_PCI_SEG1_PORTIO_MIN       0x10000
-#define SYNQUACER_PCI_SEG1_PORTIO_MAX       0x1ffff
-#define SYNQUACER_PCI_SEG1_PORTIO_SIZE      0x10000
+#define SYNQUACER_PCI_SEG1_PORTIO_MIN       0x8000
+#define SYNQUACER_PCI_SEG1_PORTIO_MAX       0xffff
 #define SYNQUACER_PCI_SEG1_PORTIO_MEMBASE   0x77f00000
-#define SYNQUACER_PCI_SEG1_PORTIO_MEMSIZE   SYNQUACER_PCI_SEG1_PORTIO_SIZE
+#define SYNQUACER_PCI_SEG1_PORTIO_MEMSIZE   0x10000
 
 #define SYNQUACER_PCI_SEG1_MMIO32_MIN       0x78000000
 #define SYNQUACER_PCI_SEG1_MMIO32_MAX       0x7fffffff
@@ -65,4 +65,8 @@
 #define SYNQUACER_PCI_SLOT1_LOCATION        SYNQUACER_PCI_LOCATION(0, 1, 3)
 #define SYNQUACER_PCI_SLOT2_LOCATION        SYNQUACER_PCI_LOCATION(0, 1, 7)
 
+#define SYNQUACER_PCI_OS_IO_BASE            0x0
+#define SYNQUACER_PCI_OS_IO_LIMIT           0xffff
+#define SYNQUACER_PCI_OS_IO_RANGE           0x10000
+
 #endif
diff --git a/Silicon/Socionext/SynQuacer/Library/SynQuacerPciHostBridgeLib/SynQuacerPciHostBridgeLibConstructor.c b/Silicon/Socionext/SynQuacer/Library/SynQuacerPciHostBridgeLib/SynQuacerPciHostBridgeLibConstructor.c
index e4679543cc66..6a3b32f6ca55 100644
--- a/Silicon/Socionext/SynQuacer/Library/SynQuacerPciHostBridgeLib/SynQuacerPciHostBridgeLibConstructor.c
+++ b/Silicon/Socionext/SynQuacer/Library/SynQuacerPciHostBridgeLib/SynQuacerPciHostBridgeLibConstructor.c
@@ -348,8 +348,8 @@ PciInitControllerPost (
   // Region 3: port I/O range
   ConfigureWindow (DbiBase, 3,
     IoMemBase,
-    RootBridge->Io.Base,
-    RootBridge->Io.Limit - RootBridge->Io.Base + 1,
+    SYNQUACER_PCI_OS_IO_BASE,
+    SYNQUACER_PCI_OS_IO_RANGE,
     IATU_REGION_CTRL_1_OFF_OUTBOUND_0_TYPE_IO,
     0);
 
-- 
2.11.0