DynamicTablesPkg: FdtHwInfoParser: Generic Timer Parser

The Generic Timer Description Table (GTDT) is a mandatory table
required for booting a standards-based operating system. It
provides an OSPM with information about a system's Generic Timer
configuration. The Generic Timer (GT) is a standard timer interface
implemented on ARM processor-based systems. The GTDT provides OSPM
with information about a system's GT interrupt configurations, for
both per-processor timers, and platform (memory-mapped) timers.

The Generic Timer information is described in the platform Device
Tree. The Device Tree bindings for the Generic timers can be found
at:
 - linux/Documentation/devicetree/bindings/timer/arm,arch_timer.yaml

The FdtHwInfoParser implements a Generic Timer Parser that parses
the platform Device Tree to create a CM_ARM_GENERIC_TIMER_INFO
object. The CM_ARM_GENERIC_TIMER_INFO object is encapsulated in a
Configuration Manager descriptor object and added to the platform
information repository.

The platform Configuration Manager can then utilise this information
when generating the GTDT table.

Note: The Generic Timer Parser currently does not support parsing
of memory-mapped platform timers.

Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>

2 files changed, 324 insertions, 0 deletions

diff --git a/DynamicTablesPkg/Library/FdtHwInfoParserLib/GenericTimer/ArmGenericTimerParser.c b/DynamicTablesPkg/Library/FdtHwInfoParserLib/GenericTimer/ArmGenericTimerParser.c
new file mode 100644
index 0000000000..988a81221d
--- /dev/null
+++ b/DynamicTablesPkg/Library/FdtHwInfoParserLib/GenericTimer/ArmGenericTimerParser.c
@@ -0,0 +1,258 @@
+/** @file

+  Arm generic timer parser.

+

+  Copyright (c) 2021, ARM Limited. All rights reserved.<BR>

+  SPDX-License-Identifier: BSD-2-Clause-Patent

+

+  @par Reference(s):

+  - linux/Documentation/devicetree/bindings/timer/arm,arch_timer.yaml

+**/

+

+#include "FdtHwInfoParser.h"

+#include "CmObjectDescUtility.h"

+#include "GenericTimer/ArmGenericTimerParser.h"

+#include "Gic/ArmGicDispatcher.h"

+

+/** List of "compatible" property values for timer nodes.

+

+  Other "compatible" values are not supported by this module.

+*/

+STATIC CONST COMPATIBILITY_STR  TimerCompatibleStr[] = {

+  { "arm,armv7-timer" },

+  { "arm,armv8-timer" }

+};

+

+/** Timer compatiblity information.

+*/

+STATIC CONST COMPATIBILITY_INFO  TimerCompatibleInfo = {

+  ARRAY_SIZE (TimerCompatibleStr),

+  TimerCompatibleStr

+};

+

+/** Parse a timer node.

+

+  @param [in]  Fdt                Pointer to a Flattened Device Tree (Fdt).

+  @param [in]  TimerNode          Offset of a timer node.

+  @param [in]  GenericTimerInfo   The CM_ARM_BOOT_ARCH_INFO to populate.

+

+  @retval EFI_SUCCESS             The function completed successfully.

+  @retval EFI_ABORTED             An error occurred.

+  @retval EFI_INVALID_PARAMETER   Invalid parameter.

+**/

+STATIC

+EFI_STATUS

+EFIAPI

+TimerNodeParser (

+  IN  CONST VOID                       *Fdt,

+  IN        INT32                      TimerNode,

+  IN        CM_ARM_GENERIC_TIMER_INFO  *GenericTimerInfo

+  )

+{

+  EFI_STATUS    Status;

+  CONST UINT32  *Data;

+  INT32         IntcNode;

+  UINT32        GicVersion;

+  INT32         DataSize;

+  INT32         IntCells;

+  BOOLEAN       AlwaysOnTimer;

+

+  if ((Fdt == NULL) ||

+      (GenericTimerInfo == NULL))

+  {

+    ASSERT (0);

+    return EFI_INVALID_PARAMETER;

+  }

+

+  Data = fdt_getprop (Fdt, TimerNode, "always-on", &DataSize);

+  if ((Data == NULL) || (DataSize < 0)) {

+    AlwaysOnTimer = FALSE;

+  } else {

+    AlwaysOnTimer = TRUE;

+  }

+

+  // Get the associated interrupt-controller.

+  Status = FdtGetIntcParentNode (Fdt, TimerNode, &IntcNode);

+  if (EFI_ERROR (Status)) {

+    ASSERT (0);

+    return Status;

+  }

+

+  // Check that the interrupt-controller node is a Gic.

+  Status = GetGicVersion (Fdt, IntcNode, &GicVersion);

+  if (EFI_ERROR (Status)) {

+    ASSERT (0);

+    return Status;

+  }

+

+  // Get the number of cells used to encode an interrupt.

+  Status = FdtGetInterruptCellsInfo (Fdt, IntcNode, &IntCells);

+  if (EFI_ERROR (Status)) {

+    ASSERT (0);

+    if (Status == EFI_NOT_FOUND) {

+      // Should have found the node.

+      Status = EFI_ABORTED;

+    }

+

+    return Status;

+  }

+

+  Data = fdt_getprop (Fdt, TimerNode, "interrupts", &DataSize);

+  if ((Data == NULL) ||

+      (DataSize != (FdtMaxTimerItem * IntCells * sizeof (UINT32))))

+  {

+    // If error or not FdtMaxTimerItem interrupts.

+    ASSERT (0);

+    return EFI_ABORTED;

+  }

+

+  GenericTimerInfo->SecurePL1TimerGSIV =

+    FdtGetInterruptId (&Data[FdtSecureTimerIrq * IntCells]);

+  GenericTimerInfo->SecurePL1TimerFlags =

+    FdtGetInterruptFlags (&Data[FdtSecureTimerIrq * IntCells]);

+  GenericTimerInfo->NonSecurePL1TimerGSIV =

+    FdtGetInterruptId (&Data[FdtNonSecureTimerIrq * IntCells]);

+  GenericTimerInfo->NonSecurePL1TimerFlags =

+    FdtGetInterruptFlags (&Data[FdtNonSecureTimerIrq * IntCells]);

+  GenericTimerInfo->VirtualTimerGSIV =

+    FdtGetInterruptId (&Data[FdtVirtualTimerIrq * IntCells]);

+  GenericTimerInfo->VirtualTimerFlags =

+    FdtGetInterruptFlags (&Data[FdtVirtualTimerIrq * IntCells]);

+  GenericTimerInfo->NonSecurePL2TimerGSIV =

+    FdtGetInterruptId (&Data[FdtHypervisorTimerIrq * IntCells]);

+  GenericTimerInfo->NonSecurePL2TimerFlags =

+    FdtGetInterruptFlags (&Data[FdtHypervisorTimerIrq * IntCells]);

+

+  if (AlwaysOnTimer) {

+    GenericTimerInfo->SecurePL1TimerFlags    |= BIT2;

+    GenericTimerInfo->NonSecurePL1TimerFlags |= BIT2;

+    GenericTimerInfo->VirtualTimerFlags      |= BIT2;

+    GenericTimerInfo->NonSecurePL2TimerFlags |= BIT2;

+  }

+

+  // Setup default values

+  // The CntControlBase & CntReadBase Physical Address are optional if

+  // the system implements EL3 (Security Extensions). So, initialise

+  // these to their default value.

+  GenericTimerInfo->CounterControlBaseAddress = 0xFFFFFFFFFFFFFFFF;

+  GenericTimerInfo->CounterReadBaseAddress    = 0xFFFFFFFFFFFFFFFF;

+

+  // For systems not implementing ARMv8.1 VHE, this field is 0.

+  GenericTimerInfo->VirtualPL2TimerGSIV  = 0;

+  GenericTimerInfo->VirtualPL2TimerFlags = 0;

+

+  return EFI_SUCCESS;

+}

+

+/** CM_ARM_GENERIC_TIMER_INFO parser function.

+

+  The following structure is populated:

+  typedef struct CmArmGenericTimerInfo {

+    UINT64  CounterControlBaseAddress;        // {default}

+    UINT64  CounterReadBaseAddress;           // {default}

+    UINT32  SecurePL1TimerGSIV;               // {Populated}

+    UINT32  SecurePL1TimerFlags;              // {Populated}

+    UINT32  NonSecurePL1TimerGSIV;            // {Populated}

+    UINT32  NonSecurePL1TimerFlags;           // {Populated}

+    UINT32  VirtualTimerGSIV;                 // {Populated}

+    UINT32  VirtualTimerFlags;                // {Populated}

+    UINT32  NonSecurePL2TimerGSIV;            // {Populated}

+    UINT32  NonSecurePL2TimerFlags;           // {Populated}

+    UINT32  VirtualPL2TimerGSIV;              // {default}

+    UINT32  VirtualPL2TimerFlags;             // {default}

+  } CM_ARM_GENERIC_TIMER_INFO;

+

+  A parser parses a Device Tree to populate a specific CmObj type. None,

+  one or many CmObj can be created by the parser.

+  The created CmObj are then handed to the parser's caller through the

+  HW_INFO_ADD_OBJECT interface.

+  This can also be a dispatcher. I.e. a function that not parsing a

+  Device Tree but calling other parsers.

+

+  @param [in]  FdtParserHandle A handle to the parser instance.

+  @param [in]  FdtBranch       When searching for DT node name, restrict

+                               the search to this Device Tree branch.

+

+  @retval EFI_SUCCESS             The function completed successfully.

+  @retval EFI_ABORTED             An error occurred.

+  @retval EFI_INVALID_PARAMETER   Invalid parameter.

+  @retval EFI_NOT_FOUND           Not found.

+  @retval EFI_UNSUPPORTED         Unsupported.

+**/

+EFI_STATUS

+EFIAPI

+ArmGenericTimerInfoParser (

+  IN  CONST FDT_HW_INFO_PARSER_HANDLE  FdtParserHandle,

+  IN        INT32                      FdtBranch

+  )

+{

+  EFI_STATUS                 Status;

+  UINT32                     Index;

+  INT32                      TimerNode;

+  UINT32                     TimerNodeCount;

+  CM_ARM_GENERIC_TIMER_INFO  GenericTimerInfo;

+  VOID                       *Fdt;

+

+  if (FdtParserHandle == NULL) {

+    ASSERT (0);

+    return EFI_INVALID_PARAMETER;

+  }

+

+  Fdt    = FdtParserHandle->Fdt;

+  Status = FdtCountCompatNodeInBranch (

+             Fdt,

+             FdtBranch,

+             &TimerCompatibleInfo,

+             &TimerNodeCount

+             );

+  if (EFI_ERROR (Status)) {

+    ASSERT (0);

+    return Status;

+  }

+

+  if (TimerNodeCount == 0) {

+    return EFI_NOT_FOUND;

+  }

+

+  // Parse each timer node in the branch.

+  TimerNode = FdtBranch;

+  for (Index = 0; Index < TimerNodeCount; Index++) {

+    ZeroMem (&GenericTimerInfo, sizeof (CM_ARM_GENERIC_TIMER_INFO));

+

+    Status = FdtGetNextCompatNodeInBranch (

+               Fdt,

+               FdtBranch,

+               &TimerCompatibleInfo,

+               &TimerNode

+               );

+    if (EFI_ERROR (Status)) {

+      ASSERT (0);

+      if (Status == EFI_NOT_FOUND) {

+        // Should have found the node.

+        Status = EFI_ABORTED;

+      }

+

+      return Status;

+    }

+

+    Status = TimerNodeParser (Fdt, TimerNode, &GenericTimerInfo);

+    if (EFI_ERROR (Status)) {

+      ASSERT (0);

+      return Status;

+    }

+

+    // Add the CmObj to the Configuration Manager.

+    Status = AddSingleCmObj (

+               FdtParserHandle,

+               CREATE_CM_ARM_OBJECT_ID (EArmObjGenericTimerInfo),

+               &GenericTimerInfo,

+               sizeof (CM_ARM_GENERIC_TIMER_INFO),

+               NULL

+               );

+    if (EFI_ERROR (Status)) {

+      ASSERT (0);

+      return Status;

+    }

+  } // for

+

+  return Status;

+}

diff --git a/DynamicTablesPkg/Library/FdtHwInfoParserLib/GenericTimer/ArmGenericTimerParser.h b/DynamicTablesPkg/Library/FdtHwInfoParserLib/GenericTimer/ArmGenericTimerParser.h
new file mode 100644
index 0000000000..d7fa278c90
--- /dev/null
+++ b/DynamicTablesPkg/Library/FdtHwInfoParserLib/GenericTimer/ArmGenericTimerParser.h
@@ -0,0 +1,66 @@
+/** @file

+  Arm generic timer parser.

+

+  Copyright (c) 2021, ARM Limited. All rights reserved.<BR>

+  SPDX-License-Identifier: BSD-2-Clause-Patent

+

+  @par Reference(s):

+  - linux/Documentation/devicetree/bindings/timer/arm,arch_timer.yaml

+**/

+

+#ifndef ARM_GENERIC_TIMER_PARSER_H_

+#define ARM_GENERIC_TIMER_PARSER_H_

+

+/** An enum listing the FDT interrupt items.

+*/

+typedef enum FdtTimerInterruptItems {

+  FdtSecureTimerIrq,      ///< Secure timer IRQ

+  FdtNonSecureTimerIrq,   ///< Non-secure timer IRQ

+  FdtVirtualTimerIrq,     ///< Virtual timer IRQ

+  FdtHypervisorTimerIrq,  ///< Hypervisor timer IRQ

+  FdtMaxTimerItem         ///< Max timer item

+} FDT_TIMER_INTERRUPT_ITEMS;

+

+/** CM_ARM_BOOT_ARCH_INFO parser function.

+

+  The following structure is populated:

+  typedef struct CmArmGenericTimerInfo {

+    UINT64  CounterControlBaseAddress;        // {default}

+    UINT64  CounterReadBaseAddress;           // {default}

+    UINT32  SecurePL1TimerGSIV;               // {Populated}

+    UINT32  SecurePL1TimerFlags;              // {Populated}

+    UINT32  NonSecurePL1TimerGSIV;            // {Populated}

+    UINT32  NonSecurePL1TimerFlags;           // {Populated}

+    UINT32  VirtualTimerGSIV;                 // {Populated}

+    UINT32  VirtualTimerFlags;                // {Populated}

+    UINT32  NonSecurePL2TimerGSIV;            // {Populated}

+    UINT32  NonSecurePL2TimerFlags;           // {Populated}

+    UINT32  VirtualPL2TimerGSIV;              // {default}

+    UINT32  VirtualPL2TimerFlags;             // {default}

+  } CM_ARM_GENERIC_TIMER_INFO;

+

+  A parser parses a Device Tree to populate a specific CmObj type. None,

+  one or many CmObj can be created by the parser.

+  The created CmObj are then handed to the parser's caller through the

+  HW_INFO_ADD_OBJECT interface.

+  This can also be a dispatcher. I.e. a function that not parsing a

+  Device Tree but calling other parsers.

+

+  @param [in]  FdtParserHandle A handle to the parser instance.

+  @param [in]  FdtBranch       When searching for DT node name, restrict

+                               the search to this Device Tree branch.

+

+  @retval EFI_SUCCESS             The function completed successfully.

+  @retval EFI_ABORTED             An error occurred.

+  @retval EFI_INVALID_PARAMETER   Invalid parameter.

+  @retval EFI_NOT_FOUND           Not found.

+  @retval EFI_UNSUPPORTED         Unsupported.

+**/

+EFI_STATUS

+EFIAPI

+ArmGenericTimerInfoParser (

+  IN  CONST FDT_HW_INFO_PARSER_HANDLE  FdtParserHandle,

+  IN        INT32                      FdtBranch

+  );

+

+#endif // ARM_GENERIC_TIMER_PARSER_H_