From 5cfb9e3e9ddee672d9a8d99ce11f6c181bf4ae3d Mon Sep 17 00:00:00 2001
From: Stefan Kalkowski <stefan.kalkowski@genode-labs.com>
Date: Tue, 14 Jun 2022 11:22:50 +0200
Subject: [PATCH] base-hw: distinguish core, idle, user threads

Do not only distinguish core and user threads, but the idle threads too.
Instead of a boolean value, introduce a new thread type.

Ref genodelabs/genode#4527
---
 repos/base-hw/src/core/kernel/cpu.cc    |  3 ++-
 repos/base-hw/src/core/kernel/thread.cc | 14 +++++++-------
 repos/base-hw/src/core/kernel/thread.h  | 11 ++++++++---
 3 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/repos/base-hw/src/core/kernel/cpu.cc b/repos/base-hw/src/core/kernel/cpu.cc
index 7840d39acb..02e190d63e 100644
--- a/repos/base-hw/src/core/kernel/cpu.cc
+++ b/repos/base-hw/src/core/kernel/cpu.cc
@@ -109,7 +109,8 @@ Cpu::Idle_thread::Idle_thread(Board::Address_space_id_allocator &addr_space_id_a
                               Cpu                               &cpu,
                               Pd                                &core_pd)
 :
-	Thread { addr_space_id_alloc, user_irq_pool, cpu_pool, core_pd, "idle" }
+	Thread { addr_space_id_alloc, user_irq_pool, cpu_pool, core_pd,
+	         Cpu_priority::min(), 0, "idle", Thread::IDLE }
 {
 	regs->ip = (addr_t)&idle_thread_main;
 
diff --git a/repos/base-hw/src/core/kernel/thread.cc b/repos/base-hw/src/core/kernel/thread.cc
index 0d2e9227e7..5d17a3a559 100644
--- a/repos/base-hw/src/core/kernel/thread.cc
+++ b/repos/base-hw/src/core/kernel/thread.cc
@@ -369,7 +369,7 @@ void Thread::_call_restart_thread()
 
 	Thread &thread = *thread_ptr;
 
-	if (!_core && (&pd() != &thread.pd())) {
+	if (_type == USER && (&pd() != &thread.pd())) {
 		raw(*this, ": failed to lookup thread ", (unsigned)user_arg_1(),
 		        " to restart it");
 		_die();
@@ -793,7 +793,7 @@ void Thread::_call()
 	case call_id_pause_vm():                 _call_pause_vm(); return;
 	default:
 		/* check wether this is a core thread */
-		if (!_core) {
+		if (_type != CORE) {
 			Genode::raw(*this, ": not entitled to do kernel call");
 			_die();
 			return;
@@ -805,7 +805,7 @@ void Thread::_call()
 		_call_new<Thread>(_addr_space_id_alloc, _user_irq_pool, _cpu_pool,
 		                  _core_pd, (unsigned) user_arg_2(),
 		                  (unsigned) _core_to_kernel_quota(user_arg_3()),
-		                  (char const *) user_arg_4());
+		                  (char const *) user_arg_4(), USER);
 		return;
 	case call_id_new_core_thread():
 		_call_new<Thread>(_addr_space_id_alloc, _user_irq_pool, _cpu_pool,
@@ -857,7 +857,7 @@ void Thread::_mmu_exception()
 		return;
 	}
 
-	if (_core)
+	if (_type != USER)
 		Genode::raw(*this, " raised a fault, which should never happen ",
 		            _fault);
 
@@ -874,7 +874,7 @@ Thread::Thread(Board::Address_space_id_allocator &addr_space_id_alloc,
                unsigned                    const  priority,
                unsigned                    const  quota,
                char                 const *const  label,
-               bool                               core)
+               Type                               type)
 :
 	Kernel::Object       { *this },
 	Cpu_job              { priority, quota },
@@ -885,8 +885,8 @@ Thread::Thread(Board::Address_space_id_allocator &addr_space_id_alloc,
 	_ipc_node            { *this },
 	_state               { AWAITS_START },
 	_label               { label },
-	_core                { core },
-	regs                 { core }
+	_type                { type },
+	regs                 { type != USER }
 { }
 
 
diff --git a/repos/base-hw/src/core/kernel/thread.h b/repos/base-hw/src/core/kernel/thread.h
index f7516a6ba9..30f774163d 100644
--- a/repos/base-hw/src/core/kernel/thread.h
+++ b/repos/base-hw/src/core/kernel/thread.h
@@ -57,6 +57,10 @@ struct Kernel::Thread_fault
  */
 class Kernel::Thread : private Kernel::Object, public Cpu_job, private Timeout
 {
+	public:
+
+		enum Type { USER, CORE, IDLE };
+
 	private:
 
 		/*
@@ -149,7 +153,7 @@ class Kernel::Thread : private Kernel::Object, public Cpu_job, private Timeout
 		capid_t                            _timeout_sigid            { 0 };
 		bool                               _paused                   { false };
 		bool                               _cancel_next_await_signal { false };
-		bool const                         _core                     { false };
+		Type const                         _type;
 
 		Genode::Constructible<Tlb_invalidation> _tlb_invalidation {};
 		Genode::Constructible<Destroy>          _destroy {};
@@ -301,7 +305,7 @@ class Kernel::Thread : private Kernel::Object, public Cpu_job, private Timeout
 		       unsigned                    const  priority,
 		       unsigned                    const  quota,
 		       char                 const *const  label,
-		       bool                               core = false);
+		       Type                        const  type);
 
 		/**
 		 * Constructor for core/kernel thread
@@ -315,7 +319,7 @@ class Kernel::Thread : private Kernel::Object, public Cpu_job, private Timeout
 		       char                 const *const  label)
 		:
 			Thread(addr_space_id_alloc, user_irq_pool, cpu_pool, core_pd,
-			       Cpu_priority::min(), 0, label, true)
+			       Cpu_priority::min(), 0, label, CORE)
 		{ }
 
 		~Thread();
@@ -432,6 +436,7 @@ class Kernel::Thread : private Kernel::Object, public Cpu_job, private Timeout
 		char const * label() const { return _label; }
 		Thread_fault fault() const { return _fault; }
 		Genode::Native_utcb *utcb() { return _utcb; }
+		Type type() const { return _type; }
 
 		Pd &pd() const
 		{