WIP dde_linux: fix IRQ masking/unmasking

Unmasking of a pending interrupt did not lead to immediate IRQ handler execution in all cases. Issue #5164
genodelabs · Mar 25, 2024 · fb00f4a · skalk · Mar 26, 2024 · chelmuth
1 parent ac5ed43
commit fb00f4a
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Showing 12 changed files with 92 additions and 98 deletions.
diff --git a/repos/dde_linux/src/include/lx_emul/irq.h b/repos/dde_linux/src/include/lx_emul/irq.h
@@ -33,6 +33,8 @@ extern void * lx_emul_irq_task_struct;
 
 int lx_emul_pending_irq(void);
 
+void lx_emul_reset_pending_irq(unsigned int irq);
+
 int lx_emul_irq_init(struct device_node *node, struct device_node *parent);
 
 unsigned long lx_emul_irq_enable(void);

diff --git a/repos/dde_linux/src/include/lx_kit/device.h b/repos/dde_linux/src/include/lx_kit/device.h
@@ -23,7 +23,6 @@
 #include <util/list.h>
 #include <util/xml_node.h>
 
-#include <lx_kit/pending_irq.h>
 
 namespace Lx_kit {
 	using namespace Genode;
@@ -65,17 +64,19 @@ class Lx_kit::Device : List<Device>::Element
 			using Index = Platform::Device::Irq::Index;
 
 			Index                  idx;
-			Pending_irq            number;
+			unsigned               number;
 			Io_signal_handler<Irq> handler;
 			bool                   masked  { true  };
-			bool                   occured { false };
+			bool                   pending { false };
 
 			Constructible<Platform::Device::Irq> session {};
 
 			Irq(Entrypoint & ep, unsigned idx, unsigned number);
 
 			void _handle();
-			void handle();
+			void mask();
+			void unmask(Platform::Device &);
+			void ack();
 		};
 
 		struct Io_port : List<Io_port>::Element
@@ -169,6 +170,8 @@ class Lx_kit::Device : List<Device>::Element
 		bool   irq_unmask(unsigned irq);
 		void   irq_mask(unsigned irq);
 		void   irq_ack(unsigned irq);
+		int    pending_irq();
+		void   reset_pending(unsigned irq);
 
 		bool   read_config(unsigned reg, unsigned len, unsigned *val);
 		bool   write_config(unsigned reg, unsigned len, unsigned  val);

diff --git a/repos/dde_linux/src/include/lx_kit/env.h b/repos/dde_linux/src/include/lx_kit/env.h
@@ -22,7 +22,6 @@
 #include <lx_kit/memory.h>
 #include <lx_kit/scheduler.h>
 #include <lx_kit/timeout.h>
-#include <lx_kit/pending_irq.h>
 
 namespace Lx_kit {
 

diff --git a/repos/dde_linux/src/include/lx_kit/pending_irq.h b/repos/dde_linux/src/include/lx_kit/pending_irq.h
diff --git a/repos/dde_linux/src/include/lx_kit/scheduler.h b/repos/dde_linux/src/include/lx_kit/scheduler.h
@@ -18,7 +18,6 @@
 #include <util/fifo.h>
 #include <util/list.h>
 #include <lx_kit/task.h>
-#include <lx_kit/pending_irq.h>
 
 namespace Lx_kit {
 	class Scheduler;
@@ -45,8 +44,6 @@ class Lx_kit::Scheduler
 
 		void _execute();
 
-		Genode::Fifo<Lx_kit::Pending_irq> _pending_irqs { };
-
 	public:
 
 		Task & current();
@@ -62,13 +59,7 @@ class Lx_kit::Scheduler
 
 		void execute();
 
-		void unblock_irq_handler(Pending_irq &);
-		template <typename FN> void pending_irq(FN const &fn)
-		{
-			_pending_irqs.dequeue([&] (Pending_irq const &pirq) {
-				fn(pirq.value); });
-		}
-
+		void unblock_irq_handler();
 		void unblock_time_handler();
 
 		Task & task(void * t);

diff --git a/repos/dde_linux/src/lib/lx_emul/irq.cc b/repos/dde_linux/src/lib/lx_emul/irq.cc
@@ -43,8 +43,17 @@ extern "C" int lx_emul_pending_irq()
 {
 	int pending_irq = -1;
 
-	Lx_kit::env().scheduler.pending_irq([&] (unsigned int irq) {
-		pending_irq = (int)irq; });
+	Lx_kit::env().devices.for_each([&] (Lx_kit::Device & d) {
+		if (pending_irq == -1)
+			pending_irq = d.pending_irq();
+	});
 
 	return pending_irq;
 }
+
+
+extern "C" void lx_emul_reset_pending_irq(unsigned int irq)
+{
+	Lx_kit::env().devices.for_each([&] (Lx_kit::Device & d) {
+		d.reset_pending(irq); });
+}
diff --git a/repos/dde_linux/src/lib/lx_emul/pci.cc b/repos/dde_linux/src/lib/lx_emul/pci.cc
@@ -60,7 +60,7 @@ lx_emul_pci_for_each_device(void * bus, lx_emul_add_device_callback_t fn)
 	env().devices.for_each([&] (Device & d) {
 		unsigned irq = 0;
 		d.for_each_irq([&] (Device::Irq & i) {
-			if (!irq) irq = i.number.value; });
+			if (!irq) irq = i.number; });
 
 		d.for_pci_config([&] (Device::Pci_config & cfg) {
 			fn(bus, num++, d.name().string(), cfg.vendor_id, cfg.device_id,

diff --git a/repos/dde_linux/src/lib/lx_emul/pin.cc b/repos/dde_linux/src/lib/lx_emul/pin.cc
@@ -30,7 +30,7 @@ namespace {
 
 			Lx_kit::Env &_env;
 
-			Lx_kit::Pending_irq _pending_irq { 0 };
+			unsigned _pending_irq = 0;
 
 		public:
 
@@ -40,9 +40,9 @@ namespace {
 
 			void trigger_irq(Number number)
 			{
-				_pending_irq.value = number.value;
+				_pending_irq = number.value;
 
-				_env.scheduler.unblock_irq_handler(_pending_irq);
+				_env.scheduler.unblock_irq_handler();
 				_env.scheduler.schedule();
 			}
 	};
@@ -223,9 +223,6 @@ extern "C" void lx_emul_pin_control(char const *pin_name, bool enabled)
 }
 
 
-extern "C" void lx_emul_backtrace(void);
-
-
 extern "C" int lx_emul_pin_sense(char const *pin_name)
 {
 	bool result = false;

diff --git a/repos/dde_linux/src/lib/lx_emul/spec/x86/irqchip.c b/repos/dde_linux/src/lib/lx_emul/spec/x86/irqchip.c
@@ -30,6 +30,12 @@ static void dde_irq_mask(struct irq_data *d)
 }
 
 
+static void dde_irq_ack(struct irq_data *d)
+{
+	lx_emul_reset_pending_irq(d->hwirq);
+}
+
+
 int lx_emul_irq_init(struct device_node *node, struct device_node *parent)
 {
 	return 0;
@@ -41,7 +47,7 @@ struct irq_chip dde_irqchip_data_chip = {
 	.irq_mask       = dde_irq_mask,
 	.irq_disable    = dde_irq_mask,
 	.irq_unmask     = dde_irq_unmask,
-	.irq_mask_ack   = dde_irq_mask,
+	.irq_ack        = dde_irq_ack,
 };
 
 
@@ -54,7 +60,6 @@ int lx_emul_irq_task_function(void * data)
 		lx_emul_task_schedule(true);
 
 		for (;;) {
-
 			irq = lx_emul_pending_irq();
 			if (irq == -1)
 				break;
@@ -64,8 +69,7 @@ int lx_emul_irq_task_function(void * data)
 
 			if (!irq) {
 				ack_bad_irq(irq);
-				WARN_ONCE(true, "Unexpected interrupt %d received!\n",
-				          irq);
+				WARN_ONCE(true, "Unexpected interrupt %d received!\n", irq);
 			} else {
 				generic_handle_irq(irq);
 				lx_emul_irq_eoi(irq);

diff --git a/repos/dde_linux/src/lib/lx_emul/virt/irq.cc b/repos/dde_linux/src/lib/lx_emul/virt/irq.cc
@@ -25,12 +25,4 @@ extern "C" void lx_emul_irq_mask(unsigned int ) { }
 extern "C" void lx_emul_irq_eoi(unsigned int ) { }
 
 
-extern "C" int lx_emul_pending_irq()
-{
-	int pending_irq = -1;
-
-	Lx_kit::env().scheduler.pending_irq([&] (unsigned int irq) {
-		pending_irq = (int)irq; });
-
-	return pending_irq;
-}
+extern "C" int lx_emul_pending_irq() { return -1; }
diff --git a/repos/dde_linux/src/lib/lx_kit/device.cc b/repos/dde_linux/src/lib/lx_kit/device.cc
@@ -38,25 +38,43 @@ bool Device::Io_port::match(uint16_t addr)
 }
 
 
-/****************
- ** Device::Irq**
- ****************/
+/*****************
+ ** Device::Irq **
+ *****************/
 
 void Device::Irq::_handle()
 {
-	handle();
+	pending = true;
+
+	env().scheduler.unblock_irq_handler();
 	env().scheduler.schedule();
 }
 
 
-void Device::Irq::handle()
+void Device::Irq::ack()
 {
-	occured = true;
+	if (session.constructed())
+		session->ack();
+}
 
-	if (masked)
-		return;
 
-	env().scheduler.unblock_irq_handler(number);
+void Device::Irq::mask()
+{
+	masked = true;
+}
+
+
+void Device::Irq::unmask(Platform::Device &dev)
+{
+	if (!session.constructed()) {
+		session.construct(dev, idx);
+		session->sigh_omit_initial_signal(handler);
+		session->ack();
+	}
+
+	masked = false;
+
+	env().scheduler.unblock_irq_handler();
 }
 
 
@@ -139,25 +157,42 @@ void * Device::io_mem_local_addr(addr_t phys_addr, size_t size)
 }
 
 
+int Device::pending_irq()
+{
+	if (!_pdev.constructed())
+		return -1;
+
+	int result = -1;
+
+	for_each_irq([&] (Irq & irq) {
+		if (result == -1 && !irq.masked && irq.pending)
+			result = irq.number;
+	});
+
+	return result;
+}
+
+
+void Device::reset_pending(unsigned number)
+{
+	for_each_irq([&] (Irq & irq) {
+		if (irq.number == number)
+			irq.pending = false;
+	});
+}
+
+
 bool Device::irq_unmask(unsigned number)
 {
 	bool ret = false;
 
 	for_each_irq([&] (Irq & irq) {
-		if (irq.number.value != number)
+		if (irq.number != number)
 			return;
 
 		ret = true;
 		enable();
-
-		if (!irq.session.constructed()) {
-			irq.session.construct(*_pdev, irq.idx);
-			irq.session->sigh_omit_initial_signal(irq.handler);
-			irq.session->ack();
-		}
-
-		irq.masked = false;
-		if (irq.occured) irq.handle();
+		irq.unmask(*_pdev);
 	});
 
 	return ret;
@@ -170,8 +205,7 @@ void Device::irq_mask(unsigned number)
 		return;
 
 	for_each_irq([&] (Irq & irq) {
-		if (irq.number.value == number) irq.masked = true; });
-
+		if (irq.number == number) irq.mask(); });
 }
 
 
@@ -181,10 +215,9 @@ void Device::irq_ack(unsigned number)
 		return;
 
 	for_each_irq([&] (Irq & irq) {
-		if (irq.number.value != number || !irq.occured || !irq.session.constructed())
+		if (irq.number != number)
 			return;
-		irq.occured = false;
-		irq.session->ack();
+		irq.ack();
 	});
 }
 

diff --git a/repos/dde_linux/src/lib/lx_kit/scheduler.cc b/repos/dde_linux/src/lib/lx_kit/scheduler.cc
@@ -74,10 +74,8 @@ void Scheduler::remove(Task & task)
 }
 
 
-void Scheduler::unblock_irq_handler(Pending_irq &pirq)
+void Scheduler::unblock_irq_handler()
 {
-	_pending_irqs.enqueue(pirq);
-
 	for (Task * t = _present_list.first(); t; t = t->next()) {
 		if (t->type() == Task::IRQ_HANDLER) t->unblock();
 	}