kernel: Resolve sign conversion warnings

Uncovered a bug within Thread's SetCoreAndAffinityMask() where an
unsigned variable (ideal_core) was being compared against "< 0", which
would always be a false condition.

We can also get rid of an unused function (GetNextProcessorId) which contained a sign
mismatch warning.

src/core/hle/kernel/scheduler.cpp

@@ -35,12 +35,12 @@ void GlobalScheduler::RemoveThread(const Thread* thread) {
                       thread_list.end());
 }
 
-void GlobalScheduler::UnloadThread(s32 core) {
+void GlobalScheduler::UnloadThread(std::size_t core) {
     Scheduler& sched = system.Scheduler(core);
     sched.UnloadThread();
 }
 
-void GlobalScheduler::SelectThread(u32 core) {
+void GlobalScheduler::SelectThread(std::size_t core) {
     const auto update_thread = [](Thread* thread, Scheduler& sched) {
         if (thread != sched.selected_thread) {
             if (thread == nullptr) {
@@ -77,9 +77,9 @@ void GlobalScheduler::SelectThread(u32 core) {
     // if we got a suggested thread, select it, else do a second pass.
     if (winner && winner->GetPriority() > 2) {
         if (winner->IsRunning()) {
-            UnloadThread(winner->GetProcessorID());
+            UnloadThread(static_cast<u32>(winner->GetProcessorID()));
         }
-        TransferToCore(winner->GetPriority(), core, winner);
+        TransferToCore(winner->GetPriority(), static_cast<s32>(core), winner);
         update_thread(winner, sched);
         return;
     }
@@ -91,9 +91,9 @@ void GlobalScheduler::SelectThread(u32 core) {
             Thread* thread_on_core = scheduled_queue[src_core].front();
             Thread* to_change = *it;
             if (thread_on_core->IsRunning() || to_change->IsRunning()) {
-                UnloadThread(src_core);
+                UnloadThread(static_cast<u32>(src_core));
             }
-            TransferToCore(thread_on_core->GetPriority(), core, thread_on_core);
+            TransferToCore(thread_on_core->GetPriority(), static_cast<s32>(core), thread_on_core);
             current_thread = thread_on_core;
             break;
         }
@@ -154,9 +154,9 @@ bool GlobalScheduler::YieldThreadAndBalanceLoad(Thread* yielding_thread) {
     if (winner != nullptr) {
         if (winner != yielding_thread) {
             if (winner->IsRunning()) {
-                UnloadThread(winner->GetProcessorID());
+                UnloadThread(static_cast<u32>(winner->GetProcessorID()));
             }
-            TransferToCore(winner->GetPriority(), core_id, winner);
+            TransferToCore(winner->GetPriority(), s32(core_id), winner);
         }
     } else {
         winner = next_thread;
@@ -196,9 +196,9 @@ bool GlobalScheduler::YieldThreadAndWaitForLoadBalancing(Thread* yielding_thread
         if (winner != nullptr) {
             if (winner != yielding_thread) {
                 if (winner->IsRunning()) {
-                    UnloadThread(winner->GetProcessorID());
+                    UnloadThread(static_cast<u32>(winner->GetProcessorID()));
                 }
-                TransferToCore(winner->GetPriority(), core_id, winner);
+                TransferToCore(winner->GetPriority(), static_cast<s32>(core_id), winner);
             }
         } else {
             winner = yielding_thread;
@@ -248,7 +248,7 @@ void GlobalScheduler::PreemptThreads() {
 
         if (winner != nullptr) {
             if (winner->IsRunning()) {
-                UnloadThread(winner->GetProcessorID());
+                UnloadThread(static_cast<u32>(winner->GetProcessorID()));
             }
             TransferToCore(winner->GetPriority(), s32(core_id), winner);
             current_thread =
@@ -281,7 +281,7 @@ void GlobalScheduler::PreemptThreads() {
 
             if (winner != nullptr) {
                 if (winner->IsRunning()) {
-                    UnloadThread(winner->GetProcessorID());
+                    UnloadThread(static_cast<u32>(winner->GetProcessorID()));
                 }
                 TransferToCore(winner->GetPriority(), s32(core_id), winner);
                 current_thread = winner;
@@ -292,30 +292,30 @@ void GlobalScheduler::PreemptThreads() {
     }
 }
 
-void GlobalScheduler::Suggest(u32 priority, u32 core, Thread* thread) {
+void GlobalScheduler::Suggest(u32 priority, std::size_t core, Thread* thread) {
     suggested_queue[core].add(thread, priority);
 }
 
-void GlobalScheduler::Unsuggest(u32 priority, u32 core, Thread* thread) {
+void GlobalScheduler::Unsuggest(u32 priority, std::size_t core, Thread* thread) {
     suggested_queue[core].remove(thread, priority);
 }
 
-void GlobalScheduler::Schedule(u32 priority, u32 core, Thread* thread) {
+void GlobalScheduler::Schedule(u32 priority, std::size_t core, Thread* thread) {
     ASSERT_MSG(thread->GetProcessorID() == s32(core), "Thread must be assigned to this core.");
     scheduled_queue[core].add(thread, priority);
 }
 
-void GlobalScheduler::SchedulePrepend(u32 priority, u32 core, Thread* thread) {
+void GlobalScheduler::SchedulePrepend(u32 priority, std::size_t core, Thread* thread) {
     ASSERT_MSG(thread->GetProcessorID() == s32(core), "Thread must be assigned to this core.");
     scheduled_queue[core].add(thread, priority, false);
 }
 
-void GlobalScheduler::Reschedule(u32 priority, u32 core, Thread* thread) {
+void GlobalScheduler::Reschedule(u32 priority, std::size_t core, Thread* thread) {
     scheduled_queue[core].remove(thread, priority);
     scheduled_queue[core].add(thread, priority);
 }
 
-void GlobalScheduler::Unschedule(u32 priority, u32 core, Thread* thread) {
+void GlobalScheduler::Unschedule(u32 priority, std::size_t core, Thread* thread) {
     scheduled_queue[core].remove(thread, priority);
 }
 
@@ -327,14 +327,14 @@ void GlobalScheduler::TransferToCore(u32 priority, s32 destination_core, Thread*
     }
     thread->SetProcessorID(destination_core);
     if (source_core >= 0) {
-        Unschedule(priority, source_core, thread);
+        Unschedule(priority, static_cast<u32>(source_core), thread);
     }
     if (destination_core >= 0) {
-        Unsuggest(priority, destination_core, thread);
+        Unsuggest(priority, static_cast<u32>(destination_core), thread);
-        Schedule(priority, destination_core, thread);
+        Schedule(priority, static_cast<u32>(destination_core), thread);
     }
     if (source_core >= 0) {
-        Suggest(priority, source_core, thread);
+        Suggest(priority, static_cast<u32>(source_core), thread);
     }
 }
 
@@ -357,7 +357,7 @@ void GlobalScheduler::Shutdown() {
     thread_list.clear();
 }
 
-Scheduler::Scheduler(Core::System& system, Core::ARM_Interface& cpu_core, u32 core_id)
+Scheduler::Scheduler(Core::System& system, Core::ARM_Interface& cpu_core, std::size_t core_id)
     : system(system), cpu_core(cpu_core), core_id(core_id) {}
 
 Scheduler::~Scheduler() = default;

src/core/hle/kernel/scheduler.h

@@ -42,41 +42,34 @@ public:
      * Add a thread to the suggested queue of a cpu core. Suggested threads may be
      * picked if no thread is scheduled to run on the core.
      */
-    void Suggest(u32 priority, u32 core, Thread* thread);
+    void Suggest(u32 priority, std::size_t core, Thread* thread);
 
     /**
      * Remove a thread to the suggested queue of a cpu core. Suggested threads may be
      * picked if no thread is scheduled to run on the core.
      */
-    void Unsuggest(u32 priority, u32 core, Thread* thread);
+    void Unsuggest(u32 priority, std::size_t core, Thread* thread);
 
     /**
      * Add a thread to the scheduling queue of a cpu core. The thread is added at the
      * back the queue in its priority level.
      */
-    void Schedule(u32 priority, u32 core, Thread* thread);
+    void Schedule(u32 priority, std::size_t core, Thread* thread);
 
     /**
      * Add a thread to the scheduling queue of a cpu core. The thread is added at the
      * front the queue in its priority level.
      */
-    void SchedulePrepend(u32 priority, u32 core, Thread* thread);
+    void SchedulePrepend(u32 priority, std::size_t core, Thread* thread);
 
     /// Reschedule an already scheduled thread based on a new priority
-    void Reschedule(u32 priority, u32 core, Thread* thread);
+    void Reschedule(u32 priority, std::size_t core, Thread* thread);
 
     /// Unschedules a thread.
-    void Unschedule(u32 priority, u32 core, Thread* thread);
+    void Unschedule(u32 priority, std::size_t core, Thread* thread);
-
-    /**
-     * Transfers a thread into an specific core. If the destination_core is -1
-     * it will be unscheduled from its source code and added into its suggested
-     * queue.
-     */
-    void TransferToCore(u32 priority, s32 destination_core, Thread* thread);
 
     /// Selects a core and forces it to unload its current thread's context
-    void UnloadThread(s32 core);
+    void UnloadThread(std::size_t core);
 
     /**
      * Takes care of selecting the new scheduled thread in three steps:
@@ -90,9 +83,9 @@ public:
      * 3. Third is no suggested thread is found, we do a second pass and pick a running
      *    thread in another core and swap it with its current thread.
      */
-    void SelectThread(u32 core);
+    void SelectThread(std::size_t core);
 
-    bool HaveReadyThreads(u32 core_id) const {
+    bool HaveReadyThreads(std::size_t core_id) const {
         return !scheduled_queue[core_id].empty();
     }
 
@@ -145,6 +138,13 @@ public:
     void Shutdown();
 
 private:
+    /**
+     * Transfers a thread into an specific core. If the destination_core is -1
+     * it will be unscheduled from its source code and added into its suggested
+     * queue.
+     */
+    void TransferToCore(u32 priority, s32 destination_core, Thread* thread);
+
     bool AskForReselectionOrMarkRedundant(Thread* current_thread, const Thread* winner);
 
     static constexpr u32 min_regular_priority = 2;
@@ -163,7 +163,7 @@ private:
 
 class Scheduler final {
 public:
-    explicit Scheduler(Core::System& system, Core::ARM_Interface& cpu_core, u32 core_id);
+    explicit Scheduler(Core::System& system, Core::ARM_Interface& cpu_core, std::size_t core_id);
     ~Scheduler();
 
     /// Returns whether there are any threads that are ready to run.
@@ -220,7 +220,7 @@ private:
     Core::ARM_Interface& cpu_core;
     u64 last_context_switch_time = 0;
     u64 idle_selection_count = 0;
-    const u32 core_id;
+    const std::size_t core_id;
 
     bool is_context_switch_pending = false;
 };

src/core/hle/kernel/thread.cpp

@@ -77,18 +77,6 @@ void Thread::CancelWakeupTimer() {
                                                              callback_handle);
 }
 
-static std::optional<s32> GetNextProcessorId(u64 mask) {
-    for (s32 index = 0; index < Core::NUM_CPU_CORES; ++index) {
-        if (mask & (1ULL << index)) {
-            if (!Core::System::GetInstance().Scheduler(index).GetCurrentThread()) {
-                // Core is enabled and not running any threads, use this one
-                return index;
-            }
-        }
-    }
-    return {};
-}
-
 void Thread::ResumeFromWait() {
     ASSERT_MSG(wait_objects.empty(), "Thread is waking up while waiting for objects");
 
@@ -173,7 +161,7 @@ ResultVal<SharedPtr<Thread>> Thread::Create(KernelCore& kernel, std::string name
     if (!Memory::IsValidVirtualAddress(owner_process, entry_point)) {
         LOG_ERROR(Kernel_SVC, "(name={}): invalid entry {:016X}", name, entry_point);
         // TODO (bunnei): Find the correct error code to use here
-        return ResultCode(-1);
+        return RESULT_UNKNOWN;
     }
 
     auto& system = Core::System::GetInstance();
@@ -401,7 +389,7 @@ void Thread::SetCurrentPriority(u32 new_priority) {
 
 ResultCode Thread::SetCoreAndAffinityMask(s32 new_core, u64 new_affinity_mask) {
     const auto HighestSetCore = [](u64 mask, u32 max_cores) {
-        for (s32 core = max_cores - 1; core >= 0; core--) {
+        for (s32 core = static_cast<s32>(max_cores - 1); core >= 0; core--) {
             if (((mask >> core) & 1) != 0) {
                 return core;
             }
@@ -425,7 +413,7 @@ ResultCode Thread::SetCoreAndAffinityMask(s32 new_core, u64 new_affinity_mask) {
         if (old_affinity_mask != new_affinity_mask) {
             const s32 old_core = processor_id;
             if (processor_id >= 0 && ((affinity_mask >> processor_id) & 1) == 0) {
-                if (ideal_core < 0) {
+                if (static_cast<s32>(ideal_core) < 0) {
                     processor_id = HighestSetCore(affinity_mask, GlobalScheduler::NUM_CPU_CORES);
                 } else {
                     processor_id = ideal_core;
@@ -447,23 +435,23 @@ void Thread::AdjustSchedulingOnStatus(u32 old_flags) {
         ThreadSchedStatus::Runnable) {
         // In this case the thread was running, now it's pausing/exitting
         if (processor_id >= 0) {
-            scheduler.Unschedule(current_priority, processor_id, this);
+            scheduler.Unschedule(current_priority, static_cast<u32>(processor_id), this);
         }
 
-        for (s32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
+        for (u32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
-            if (core != processor_id && ((affinity_mask >> core) & 1) != 0) {
+            if (core != static_cast<u32>(processor_id) && ((affinity_mask >> core) & 1) != 0) {
-                scheduler.Unsuggest(current_priority, static_cast<u32>(core), this);
+                scheduler.Unsuggest(current_priority, core, this);
             }
         }
     } else if (GetSchedulingStatus() == ThreadSchedStatus::Runnable) {
         // The thread is now set to running from being stopped
         if (processor_id >= 0) {
-            scheduler.Schedule(current_priority, processor_id, this);
+            scheduler.Schedule(current_priority, static_cast<u32>(processor_id), this);
         }
 
-        for (s32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
+        for (u32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
-            if (core != processor_id && ((affinity_mask >> core) & 1) != 0) {
+            if (core != static_cast<u32>(processor_id) && ((affinity_mask >> core) & 1) != 0) {
-                scheduler.Suggest(current_priority, static_cast<u32>(core), this);
+                scheduler.Suggest(current_priority, core, this);
             }
         }
     }
@@ -477,11 +465,11 @@ void Thread::AdjustSchedulingOnPriority(u32 old_priority) {
     }
     auto& scheduler = Core::System::GetInstance().GlobalScheduler();
     if (processor_id >= 0) {
-        scheduler.Unschedule(old_priority, processor_id, this);
+        scheduler.Unschedule(old_priority, static_cast<u32>(processor_id), this);
     }
 
     for (u32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
-        if (core != processor_id && ((affinity_mask >> core) & 1) != 0) {
+        if (core != static_cast<u32>(processor_id) && ((affinity_mask >> core) & 1) != 0) {
             scheduler.Unsuggest(old_priority, core, this);
         }
     }
@@ -491,14 +479,14 @@ void Thread::AdjustSchedulingOnPriority(u32 old_priority) {
 
     if (processor_id >= 0) {
         if (current_thread == this) {
-            scheduler.SchedulePrepend(current_priority, processor_id, this);
+            scheduler.SchedulePrepend(current_priority, static_cast<u32>(processor_id), this);
         } else {
-            scheduler.Schedule(current_priority, processor_id, this);
+            scheduler.Schedule(current_priority, static_cast<u32>(processor_id), this);
         }
     }
 
     for (u32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
-        if (core != processor_id && ((affinity_mask >> core) & 1) != 0) {
+        if (core != static_cast<u32>(processor_id) && ((affinity_mask >> core) & 1) != 0) {
             scheduler.Suggest(current_priority, core, this);
         }
     }
@@ -515,7 +503,7 @@ void Thread::AdjustSchedulingOnAffinity(u64 old_affinity_mask, s32 old_core) {
 
     for (u32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
         if (((old_affinity_mask >> core) & 1) != 0) {
-            if (core == old_core) {
+            if (core == static_cast<u32>(old_core)) {
                 scheduler.Unschedule(current_priority, core, this);
             } else {
                 scheduler.Unsuggest(current_priority, core, this);
@@ -525,7 +513,7 @@ void Thread::AdjustSchedulingOnAffinity(u64 old_affinity_mask, s32 old_core) {
 
     for (u32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
         if (((affinity_mask >> core) & 1) != 0) {
-            if (core == processor_id) {
+            if (core == static_cast<u32>(processor_id)) {
                 scheduler.Schedule(current_priority, core, this);
             } else {
                 scheduler.Suggest(current_priority, core, this);

src/core/hle/kernel/vm_manager.cpp

@@ -167,7 +167,7 @@ ResultVal<VAddr> VMManager::FindFreeRegion(VAddr begin, VAddr end, u64 size) con
 
     if (vma_handle == vma_map.cend()) {
         // TODO(Subv): Find the correct error code here.
-        return ResultCode(-1);
+        return RESULT_UNKNOWN;
     }
 
     const VAddr target = std::max(begin, vma_handle->second.base);