Qemu's firmware configuration interface for ARM consists of two MMIO
registers, a 16-bit selector, and a 64-bit data register that allows the
guest to transfer data with 8, 16, 32, and 64-bit wide accesses. Parse the
base address from the DTB, and expose the registers to the rest of DXE via
dynamic PCDs.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <ler...@redhat.com>
---
Notes:
v4:
- comment on the MMIO address range ASSERT()s in InitializeVirtFdtDxe()
[Olivier]
v3:
- updated to the layout with 64-bit wide data register
v2:
- use "qemu,fw-cfg-mmio" as compatible property
- the DTB node specifies a single contiguous region
ArmPlatformPkg/ArmVirtualizationPkg/VirtFdtDxe/VirtFdtDxe.inf | 2 ++
ArmPlatformPkg/ArmVirtualizationPkg/VirtFdtDxe/VirtFdtDxe.c | 34
++++++++++++++++++++++++++++++++++
ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationPkg.dec | 3 +++
ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationQemu.dsc | 3 +++
4 files changed, 42 insertions(+)
diff --git a/ArmPlatformPkg/ArmVirtualizationPkg/VirtFdtDxe/VirtFdtDxe.inf
b/ArmPlatformPkg/ArmVirtualizationPkg/VirtFdtDxe/VirtFdtDxe.inf
index 1c9dd20..daafe6c 100644
--- a/ArmPlatformPkg/ArmVirtualizationPkg/VirtFdtDxe/VirtFdtDxe.inf
+++ b/ArmPlatformPkg/ArmVirtualizationPkg/VirtFdtDxe/VirtFdtDxe.inf
@@ -47,6 +47,8 @@
[Pcd]
gArmVirtualizationTokenSpaceGuid.PcdDeviceTreeBaseAddress
gArmVirtualizationTokenSpaceGuid.PcdArmPsciMethod
+ gArmVirtualizationTokenSpaceGuid.PcdFwCfgSelectorAddress
+ gArmVirtualizationTokenSpaceGuid.PcdFwCfgDataAddress
gArmTokenSpaceGuid.PcdGicDistributorBase
gArmTokenSpaceGuid.PcdGicInterruptInterfaceBase
gArmTokenSpaceGuid.PcdArmArchTimerSecIntrNum
diff --git a/ArmPlatformPkg/ArmVirtualizationPkg/VirtFdtDxe/VirtFdtDxe.c
b/ArmPlatformPkg/ArmVirtualizationPkg/VirtFdtDxe/VirtFdtDxe.c
index d002e66..95e91eb 100644
--- a/ArmPlatformPkg/ArmVirtualizationPkg/VirtFdtDxe/VirtFdtDxe.c
+++ b/ArmPlatformPkg/ArmVirtualizationPkg/VirtFdtDxe/VirtFdtDxe.c
@@ -44,6 +44,7 @@ typedef enum {
PropertyTypeUart,
PropertyTypeTimer,
PropertyTypePsci,
+ PropertyTypeFwCfg,
} PROPERTY_TYPE;
typedef struct {
@@ -59,6 +60,7 @@ STATIC CONST PROPERTY CompatibleProperties[] = {
{ PropertyTypeTimer, "arm,armv7-timer" },
{ PropertyTypeTimer, "arm,armv8-timer" },
{ PropertyTypePsci, "arm,psci-0.2" },
+ { PropertyTypeFwCfg, "qemu,fw-cfg-mmio" },
{ PropertyTypeUnknown, "" }
};
@@ -115,6 +117,10 @@ InitializeVirtFdtDxe (
CONST INTERRUPT_PROPERTY *InterruptProp;
INT32 SecIntrNum, IntrNum, VirtIntrNum, HypIntrNum;
CONST CHAR8 *PsciMethod;
+ UINT64 FwCfgSelectorAddress;
+ UINT64 FwCfgSelectorSize;
+ UINT64 FwCfgDataAddress;
+ UINT64 FwCfgDataSize;
DeviceTreeBase = (VOID *)(UINTN)PcdGet64 (PcdDeviceTreeBaseAddress);
ASSERT (DeviceTreeBase != NULL);
@@ -160,6 +166,34 @@ InitializeVirtFdtDxe (
(PropType == PropertyTypePsci));
switch (PropType) {
+ case PropertyTypeFwCfg:
+ ASSERT (Len == 2 * sizeof (UINT64));
+
+ FwCfgDataAddress = fdt64_to_cpu (((UINT64 *)RegProp)[0]);
+ FwCfgDataSize = 8;
+ FwCfgSelectorAddress = FwCfgDataAddress + FwCfgDataSize;
+ FwCfgSelectorSize = 2;
+
+ //
+ // The following ASSERT()s express
+ //
+ // Address + Size - 1 <= MAX_UINTN
+ //
+ // for both registers, that is, that the last byte in each MMIO range is
+ // expressible as a MAX_UINTN. The form below is mathematically
+ // equivalent, and it also prevents any unsigned overflow before the
+ // comparison.
+ //
+ ASSERT (FwCfgSelectorAddress <= MAX_UINTN - FwCfgSelectorSize + 1);
+ ASSERT (FwCfgDataAddress <= MAX_UINTN - FwCfgDataSize + 1);
+
+ PcdSet64 (PcdFwCfgSelectorAddress, FwCfgSelectorAddress);
+ PcdSet64 (PcdFwCfgDataAddress, FwCfgDataAddress);
+
+ DEBUG ((EFI_D_INFO, "Found FwCfg @ 0x%Lx/0x%Lx\n", FwCfgSelectorAddress,
+ FwCfgDataAddress));
+ break;
+
case PropertyTypeVirtio:
ASSERT (Len == 16);
//
diff --git a/ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationPkg.dec
b/ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationPkg.dec
index b581add..9941154 100644
--- a/ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationPkg.dec
+++ b/ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationPkg.dec
@@ -53,3 +53,6 @@
# PcdArmPsciMethod == 2 : use SMC
#
gArmVirtualizationTokenSpaceGuid.PcdArmPsciMethod|0|UINT32|0x00000003
+
+
gArmVirtualizationTokenSpaceGuid.PcdFwCfgSelectorAddress|0x0|UINT64|0x00000004
+ gArmVirtualizationTokenSpaceGuid.PcdFwCfgDataAddress|0x0|UINT64|0x00000005
diff --git a/ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationQemu.dsc
b/ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationQemu.dsc
index a4816fb..0f25f6d 100644
--- a/ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationQemu.dsc
+++ b/ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationQemu.dsc
@@ -173,6 +173,9 @@
gArmVirtualizationTokenSpaceGuid.PcdArmPsciMethod|0
+ gArmVirtualizationTokenSpaceGuid.PcdFwCfgSelectorAddress|0x0
+ gArmVirtualizationTokenSpaceGuid.PcdFwCfgDataAddress|0x0
+
################################################################################
#
# Components Section - list of all EDK II Modules needed by this Platform
--
1.8.3.1
------------------------------------------------------------------------------
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