[edk2-devel] [PATCH v3 13/13] ArmPkg/ArmLib: Add ArmHasEte () helper function

[Sami Mujawar]

Create a helper function to query whether ID_AA64MFR1_EL1 indicates
presence of the Embedded Trace Extension (ETE). This feature is only
visible in AARCH64 state.

Signed-off-by: Sami Mujawar <sami.mujawar at arm.com>
Cc: Ard Biesheuvel <ardb+tianocore at kernel.org>
Cc: Leif Lindholm <quic_llindhol at quicinc.com>
Cc: Pierre Gondois <pierre.gondois at arm.com>
---

Notes:
    v3:
     - New patch in this series that introduces a helper      [SAMI]
       function for platforms to query if ETE feature is
       supported.
       Ref: https://edk2.groups.io/g/devel/message/10898

 ArmPkg/Include/Chipset/AArch64.h           |  3 ++-
 ArmPkg/Include/Library/ArmLib.h            | 12 ++++++++++++
 ArmPkg/Library/ArmLib/AArch64/AArch64Lib.c | 16 ++++++++++++++++
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/ArmPkg/Include/Chipset/AArch64.h b/ArmPkg/Include/Chipset/AArch64.h
index d8711ad7112f1f983d22d98bdf8ff8607bf2ff98..5390bf0a2774fb410f33e031cb0367708905c658 100644
--- a/ArmPkg/Include/Chipset/AArch64.h
+++ b/ArmPkg/Include/Chipset/AArch64.h
@@ -32,7 +32,8 @@
 #define AARCH64_PFR0_GIC  (0xF << 24)
 
 // ID_AA64DFR0 - AArch64 Debug Feature Register 0 definitions
-#define AARCH64_DFR0_TRBE  (0xFULL << 44)
+#define AARCH64_DFR0_TRACEVER  (0xFULL << 4)
+#define AARCH64_DFR0_TRBE      (0xFULL << 44)
 
 // SCR - Secure Configuration Register definitions
 #define SCR_NS   (1 << 0)
diff --git a/ArmPkg/Include/Library/ArmLib.h b/ArmPkg/Include/Library/ArmLib.h
index c2d738c06e27a3599b79c7bd83c72f8a696b4aef..6aa8a48f07f39255b70406774d2d803dbfc97b0b 100644
--- a/ArmPkg/Include/Library/ArmLib.h
+++ b/ArmPkg/Include/Library/ArmLib.h
@@ -793,6 +793,18 @@ ArmHasTrbe (
   VOID
   );
 
+/**
+  Checks whether the CPU implements the Embedded Trace Extension.
+
+  @retval TRUE  FEAT_ETE is implemented.
+  @retval FALSE FEAT_ETE is not mplemented.
+**/
+BOOLEAN
+EFIAPI
+ArmHasEte (
+  VOID
+  );
+
 #endif // MDE_CPU_AARCH64
 
 #ifdef MDE_CPU_ARM
diff --git a/ArmPkg/Library/ArmLib/AArch64/AArch64Lib.c b/ArmPkg/Library/ArmLib/AArch64/AArch64Lib.c
index 3a46f360ef512ed68f9ec80fc486551ff7440009..87285465871dc100ea0065659959ca845912c549 100644
--- a/ArmPkg/Library/ArmLib/AArch64/AArch64Lib.c
+++ b/ArmPkg/Library/ArmLib/AArch64/AArch64Lib.c
@@ -134,3 +134,19 @@ ArmHasTrbe (
 {
   return ((ArmReadIdAA64Dfr0 () & AARCH64_DFR0_TRBE) != 0);
 }
+
+/**
+  Checks whether the CPU implements the Embedded Trace Extension.
+
+  @retval TRUE  FEAT_ETE is implemented.
+  @retval FALSE FEAT_ETE is not mplemented.
+**/
+BOOLEAN
+EFIAPI
+ArmHasEte (
+  VOID
+  )
+{
+  // The ID_AA64DFR0_EL1.TraceVer field identifies the presence of FEAT_ETE.
+  return ((ArmReadIdAA64Dfr0 () & AARCH64_DFR0_TRACEVER) != 0);
+}
-- 
'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)'



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