Merge pull request #3998 from Sonicadvance1/move_midr_fetch

HostFeatures: Moves MIDR querying to the frontend
FEX-Emu · Aug 23, 2024 · fbf62f1 · fbf62f1
2 parents e6aa268 + 0ec724c
commit fbf62f1
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Showing 5 changed files with 57 additions and 23 deletions.
diff --git a/FEXCore/Source/Interface/Core/CPUID.cpp b/FEXCore/Source/Interface/Core/CPUID.cpp
@@ -114,27 +114,16 @@ void CPUIDEmu::SetupHostHybridFlag() {
 
   uint64_t MIDR {};
   for (size_t i = 0; i < Cores; ++i) {
-    std::error_code ec {};
-    fextl::string MIDRPath = fextl::fmt::format("/sys/devices/system/cpu/cpu{}/regs/identification/midr_el1", i);
-
-    std::array<char, 18> Data;
-    // Needs to be a fixed size since depending on kernel it will try to read a full page of data and fail
-    // Only read 18 bytes for a 64bit value prefixed with 0x
-    if (FEXCore::FileLoading::LoadFileToBuffer(MIDRPath, Data) == sizeof(Data)) {
-      uint64_t NewMIDR {};
-      std::string_view MIDRView(Data.data(), sizeof(Data));
-      if (FEXCore::StrConv::Conv(MIDRView, &NewMIDR)) {
-        if (MIDR != 0 && MIDR != NewMIDR) {
-          // CPU mismatch, claim hybrid
-          Hybrid = true;
-        }
-
-        // Truncate to 32-bits, top 32-bits are all reserved in MIDR
-        PerCPUData[i].ProductName = ProductNames::ARM_UNKNOWN;
-        PerCPUData[i].MIDR = NewMIDR;
-        MIDR = NewMIDR;
-      }
+    auto NewMIDR = CTX->HostFeatures.CPUMIDRs[i];
+    if (MIDR != 0 && MIDR != NewMIDR) {
+      // CPU mismatch, claim hybrid
+      Hybrid = true;
     }
+
+    // Truncate to 32-bits, top 32-bits are all reserved in MIDR
+    PerCPUData[i].ProductName = ProductNames::ARM_UNKNOWN;
+    PerCPUData[i].MIDR = NewMIDR;
+    MIDR = NewMIDR;
   }
 
   struct CPUMIDR {
@@ -1185,7 +1174,7 @@ FEXCore::CPUID::XCRResults CPUIDEmu::XCRFunction_0h() const {
 
 CPUIDEmu::CPUIDEmu(const FEXCore::Context::ContextImpl* ctx)
   : CTX {ctx} {
-  Cores = FEXCore::CPUInfo::CalculateNumberOfCPUs();
+  Cores = CTX->HostFeatures.CPUMIDRs.size();
 
   // Setup some state tracking
   SetupHostHybridFlag();

diff --git a/FEXCore/include/FEXCore/Core/HostFeatures.h b/FEXCore/include/FEXCore/Core/HostFeatures.h
@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MIT
 #pragma once
+
+#include <FEXCore/fextl/vector.h>
 #include <cstdint>
 
 namespace FEXCore {
@@ -37,5 +39,9 @@ struct HostFeatures {
   // Float exception behaviour
   bool SupportsAFP {};
   bool SupportsFloatExceptions {};
+
+  // MIDR information
+  // Also used for determining number of CPU cores for CPUID
+  fextl::vector<uint32_t> CPUMIDRs;
 };
 } // namespace FEXCore
diff --git a/Source/Common/HostFeatures.cpp b/Source/Common/HostFeatures.cpp
@@ -3,6 +3,9 @@
 
 #include <FEXCore/Config/Config.h>
 #include <FEXCore/Core/HostFeatures.h>
+#include <FEXCore/Utils/CPUInfo.h>
+#include <FEXCore/Utils/FileLoading.h>
+#include <FEXCore/Utils/StringUtils.h>
 
 #ifdef _M_X86_64
 #define XBYAK64
@@ -17,6 +20,28 @@
 
 namespace FEX {
 
+void FillMIDRInformationViaLinux(FEXCore::HostFeatures* Features) {
+  auto Cores = FEXCore::CPUInfo::CalculateNumberOfCPUs();
+  Features->CPUMIDRs.resize(Cores);
+#ifdef _M_ARM_64
+  for (size_t i = 0; i < Cores; ++i) {
+    std::error_code ec {};
+    fextl::string MIDRPath = fextl::fmt::format("/sys/devices/system/cpu/cpu{}/regs/identification/midr_el1", i);
+    std::array<char, 18> Data;
+    // Needs to be a fixed size since depending on kernel it will try to read a full page of data and fail
+    // Only read 18 bytes for a 64bit value prefixed with 0x
+    if (FEXCore::FileLoading::LoadFileToBuffer(MIDRPath, Data) == sizeof(Data)) {
+      uint64_t MIDR {};
+      auto Results = std::from_chars(Data.data() + 2, Data.data() + sizeof(Data), MIDR, 16);
+      if (Results.ec == std::errc()) {
+        // Truncate to 32-bits, top 32-bits are all reserved in MIDR
+        Features->CPUMIDRs[i] = static_cast<uint32_t>(MIDR);
+      }
+    }
+  }
+#endif
+}
+
 #ifdef _M_ARM_64
 #define GetSysReg(name, reg)                         \
   static uint64_t Get_##name() {                     \
@@ -603,6 +628,8 @@ FEXCore::HostFeatures FetchHostFeatures() {
   __asm volatile("mrs %[midr], midr_el1" : [midr] "=r"(MIDR));
 #endif
 
-  return FetchHostFeatures(Features, true, CTR, MIDR);
+  auto HostFeatures = FetchHostFeatures(Features, true, CTR, MIDR);
+  FillMIDRInformationViaLinux(&HostFeatures);
+  return HostFeatures;
 }
 } // namespace FEX
diff --git a/Source/Common/HostFeatures.h b/Source/Common/HostFeatures.h
@@ -623,6 +623,8 @@ class CPUFeatures {
   }
 };
 
+void FillMIDRInformationViaLinux(FEXCore::HostFeatures* Features);
+
 FEXCore::HostFeatures FetchHostFeatures(FEX::CPUFeatures& Features, bool SupportsCacheMaintenanceOps, uint64_t CTR, uint64_t MIDR);
 FEXCore::HostFeatures FetchHostFeatures();
 } // namespace FEX
diff --git a/Source/Windows/Common/CPUFeatures.cpp b/Source/Windows/Common/CPUFeatures.cpp
@@ -2,13 +2,21 @@
 
 #include <FEXCore/Core/Context.h>
 #include <FEXCore/Core/HostFeatures.h>
+#include <FEXCore/Utils/CPUInfo.h>
 #include <FEXCore/fextl/fmt.h>
 
 #include <windows.h>
 
 #include "CPUFeatures.h"
 
 namespace {
+
+static void FillMIDRInformation(FEXCore::HostFeatures* Features, uint64_t MIDR) {
+  auto Cores = FEXCore::CPUInfo::CalculateNumberOfCPUs();
+  // Truncate to 32-bits, top 32-bits are all reserved in MIDR
+  Features->CPUMIDRs.resize(Cores, static_cast<uint32_t>(MIDR));
+}
+
 HKEY OpenProcessorKey(uint32_t Idx) {
   HKEY Out;
   auto Path = fextl::fmt::format("Hardware\\Description\\System\\CentralProcessor\\{}", Idx);
@@ -57,7 +65,9 @@ FEXCore::HostFeatures CPUFeatures::FetchHostFeatures(bool IsWine) {
 
   RegCloseKey(Key);
 
-  return FEX::FetchHostFeatures(Features, !IsWine, CTR, MIDR);
+  auto HostFeatures = FEX::FetchHostFeatures(Features, !IsWine, CTR, MIDR);
+  FillMIDRInformation(&HostFeatures, MIDR);
+  return HostFeatures;
 }
 
 CPUFeatures::CPUFeatures(FEXCore::Context::Context& CTX) {