core_timing: Use CNTPCT as the guest CPU tick

Previously, we were mixing the raw CPU frequency and CNTFRQ.
The raw CPU frequency (1020 MHz) should've never been used as CNTPCT (whose frequency is CNTFRQ) is the only counter available.

src/core/CMakeLists.txt

@@ -16,7 +16,6 @@ add_library(core STATIC
     core.h
     core_timing.cpp
     core_timing.h
-    core_timing_util.h
     cpu_manager.cpp
     cpu_manager.h
     crypto/aes_util.cpp

src/core/core_timing.cpp

@@ -16,7 +16,6 @@
 
 #include "common/microprofile.h"
 #include "core/core_timing.h"
-#include "core/core_timing_util.h"
 #include "core/hardware_properties.h"
 
 namespace Core::Timing {
@@ -45,9 +44,7 @@ struct CoreTiming::Event {
     }
 };
 
-CoreTiming::CoreTiming()
-    : cpu_clock{Common::CreateBestMatchingClock(Hardware::BASE_CLOCK_RATE, Hardware::CNTFREQ)},
-      event_clock{Common::CreateStandardWallClock(Hardware::BASE_CLOCK_RATE, Hardware::CNTFREQ)} {}
+CoreTiming::CoreTiming() : clock{Common::CreateOptimalClock()} {}
 
 CoreTiming::~CoreTiming() {
     Reset();
@@ -180,7 +177,7 @@ void CoreTiming::AddTicks(u64 ticks_to_add) {
 void CoreTiming::Idle() {
     if (!event_queue.empty()) {
         const u64 next_event_time = event_queue.front().time;
-        const u64 next_ticks = nsToCycles(std::chrono::nanoseconds(next_event_time)) + 10U;
+        const u64 next_ticks = Common::WallClock::NSToCNTPCT(next_event_time) + 10U;
         if (next_ticks > ticks) {
             ticks = next_ticks;
         }
@@ -193,18 +190,11 @@ void CoreTiming::ResetTicks() {
     downcount = MAX_SLICE_LENGTH;
 }
 
-u64 CoreTiming::GetCPUTicks() const {
-    if (is_multicore) [[likely]] {
-        return cpu_clock->GetCPUCycles();
-    }
-    return ticks;
-}
-
 u64 CoreTiming::GetClockTicks() const {
     if (is_multicore) [[likely]] {
-        return cpu_clock->GetClockCycles();
+        return clock->GetCNTPCT();
     }
-    return CpuCyclesToClockCycles(ticks);
+    return ticks;
 }
 
 std::optional<s64> CoreTiming::Advance() {
@@ -297,9 +287,7 @@ void CoreTiming::ThreadLoop() {
         }
 
         paused_set = true;
-        event_clock->Pause(true);
         pause_event.Wait();
-        event_clock->Pause(false);
     }
 }
 
@@ -315,25 +303,18 @@ void CoreTiming::Reset() {
     has_started = false;
 }
 
-std::chrono::nanoseconds CoreTiming::GetCPUTimeNs() const {
-    if (is_multicore) [[likely]] {
-        return cpu_clock->GetTimeNS();
-    }
-    return CyclesToNs(ticks);
-}
-
 std::chrono::nanoseconds CoreTiming::GetGlobalTimeNs() const {
     if (is_multicore) [[likely]] {
-        return event_clock->GetTimeNS();
+        return clock->GetTimeNS();
     }
-    return CyclesToNs(ticks);
+    return std::chrono::nanoseconds{Common::WallClock::CNTPCTToNS(ticks)};
 }
 
 std::chrono::microseconds CoreTiming::GetGlobalTimeUs() const {
     if (is_multicore) [[likely]] {
-        return event_clock->GetTimeUS();
+        return clock->GetTimeUS();
     }
-    return CyclesToUs(ticks);
+    return std::chrono::microseconds{Common::WallClock::CNTPCTToUS(ticks)};
 }
 
 } // namespace Core::Timing

src/core/core_timing.h

@@ -116,15 +116,9 @@ public:
         return downcount;
     }
 
-    /// Returns current time in emulated CPU cycles
-    u64 GetCPUTicks() const;
-
-    /// Returns current time in emulated in Clock cycles
+    /// Returns the current CNTPCT tick value.
     u64 GetClockTicks() const;
 
-    /// Returns current time in nanoseconds.
-    std::chrono::nanoseconds GetCPUTimeNs() const;
-
     /// Returns current time in microseconds.
     std::chrono::microseconds GetGlobalTimeUs() const;
 
@@ -142,8 +136,7 @@ private:
 
     void Reset();
 
-    std::unique_ptr<Common::WallClock> cpu_clock;
-    std::unique_ptr<Common::WallClock> event_clock;
+    std::unique_ptr<Common::WallClock> clock;
 
     s64 global_timer = 0;
 

src/core/core_timing_util.h

@@ -1,58 +0,0 @@
-// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
-// SPDX-License-Identifier: GPL-2.0-or-later
-
-#pragma once
-
-#include <chrono>
-
-#include "common/common_types.h"
-#include "core/hardware_properties.h"
-
-namespace Core::Timing {
-
-namespace detail {
-constexpr u64 CNTFREQ_ADJUSTED = Hardware::CNTFREQ / 1000;
-constexpr u64 BASE_CLOCK_RATE_ADJUSTED = Hardware::BASE_CLOCK_RATE / 1000;
-} // namespace detail
-
-[[nodiscard]] constexpr s64 msToCycles(std::chrono::milliseconds ms) {
-    return ms.count() * detail::BASE_CLOCK_RATE_ADJUSTED;
-}
-
-[[nodiscard]] constexpr s64 usToCycles(std::chrono::microseconds us) {
-    return us.count() * detail::BASE_CLOCK_RATE_ADJUSTED / 1000;
-}
-
-[[nodiscard]] constexpr s64 nsToCycles(std::chrono::nanoseconds ns) {
-    return ns.count() * detail::BASE_CLOCK_RATE_ADJUSTED / 1000000;
-}
-
-[[nodiscard]] constexpr u64 msToClockCycles(std::chrono::milliseconds ms) {
-    return static_cast<u64>(ms.count()) * detail::CNTFREQ_ADJUSTED;
-}
-
-[[nodiscard]] constexpr u64 usToClockCycles(std::chrono::microseconds us) {
-    return us.count() * detail::CNTFREQ_ADJUSTED / 1000;
-}
-
-[[nodiscard]] constexpr u64 nsToClockCycles(std::chrono::nanoseconds ns) {
-    return ns.count() * detail::CNTFREQ_ADJUSTED / 1000000;
-}
-
-[[nodiscard]] constexpr u64 CpuCyclesToClockCycles(u64 ticks) {
-    return ticks * detail::CNTFREQ_ADJUSTED / detail::BASE_CLOCK_RATE_ADJUSTED;
-}
-
-[[nodiscard]] constexpr std::chrono::milliseconds CyclesToMs(s64 cycles) {
-    return std::chrono::milliseconds(cycles / detail::BASE_CLOCK_RATE_ADJUSTED);
-}
-
-[[nodiscard]] constexpr std::chrono::nanoseconds CyclesToNs(s64 cycles) {
-    return std::chrono::nanoseconds(cycles * 1000000 / detail::BASE_CLOCK_RATE_ADJUSTED);
-}
-
-[[nodiscard]] constexpr std::chrono::microseconds CyclesToUs(s64 cycles) {
-    return std::chrono::microseconds(cycles * 1000 / detail::BASE_CLOCK_RATE_ADJUSTED);
-}
-
-} // namespace Core::Timing

src/core/hle/kernel/k_scheduler.cpp

@@ -184,7 +184,8 @@ u64 KScheduler::UpdateHighestPriorityThread(KThread* highest_thread) {
         prev_highest_thread != highest_thread) [[likely]] {
         if (prev_highest_thread != nullptr) [[likely]] {
             IncrementScheduledCount(prev_highest_thread);
-            prev_highest_thread->SetLastScheduledTick(m_kernel.System().CoreTiming().GetCPUTicks());
+            prev_highest_thread->SetLastScheduledTick(
+                m_kernel.System().CoreTiming().GetClockTicks());
         }
         if (m_state.should_count_idle) {
             if (highest_thread != nullptr) [[likely]] {
@@ -351,7 +352,7 @@ void KScheduler::SwitchThread(KThread* next_thread) {
 
     // Update the CPU time tracking variables.
     const s64 prev_tick = m_last_context_switch_time;
-    const s64 cur_tick = m_kernel.System().CoreTiming().GetCPUTicks();
+    const s64 cur_tick = m_kernel.System().CoreTiming().GetClockTicks();
     const s64 tick_diff = cur_tick - prev_tick;
     cur_thread->AddCpuTime(m_core_id, tick_diff);
     if (cur_process != nullptr) {

src/core/hle/kernel/svc/svc_info.cpp

@@ -199,9 +199,9 @@ Result GetInfo(Core::System& system, u64* result, InfoType info_id_type, Handle
         if (same_thread && info_sub_id == 0xFFFFFFFFFFFFFFFF) {
             const u64 thread_ticks = current_thread->GetCpuTime();
 
-            out_ticks = thread_ticks + (core_timing.GetCPUTicks() - prev_ctx_ticks);
+            out_ticks = thread_ticks + (core_timing.GetClockTicks() - prev_ctx_ticks);
         } else if (same_thread && info_sub_id == system.Kernel().CurrentPhysicalCoreIndex()) {
-            out_ticks = core_timing.GetCPUTicks() - prev_ctx_ticks;
+            out_ticks = core_timing.GetClockTicks() - prev_ctx_ticks;
         }
 
         *result = out_ticks;

src/core/hle/service/hid/hidbus.cpp

@@ -5,7 +5,6 @@
 #include "common/settings.h"
 #include "core/core.h"
 #include "core/core_timing.h"
-#include "core/core_timing_util.h"
 #include "core/hid/hid_types.h"
 #include "core/hle/kernel/k_event.h"
 #include "core/hle/kernel/k_readable_event.h"