1 files changed, 146 insertions, 25 deletions

diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c
index 3741d2380060..82af5191e73d 100644
--- a/arch/um/kernel/irq.c
+++ b/arch/um/kernel/irq.c
@@ -20,7 +20,7 @@
 #include <os.h>
 #include <irq_user.h>
 #include <irq_kern.h>
-#include <as-layout.h>
+#include <linux/time-internal.h>
 
 
 extern void free_irqs(void);
@@ -38,6 +38,12 @@ struct irq_reg {
 	bool active;
 	bool pending;
 	bool wakeup;
+#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
+	bool pending_on_resume;
+	void (*timetravel_handler)(int, int, void *,
+				   struct time_travel_event *);
+	struct time_travel_event event;
+#endif
 };
 
 struct irq_entry {
@@ -51,6 +57,7 @@ struct irq_entry {
 static DEFINE_SPINLOCK(irq_lock);
 static LIST_HEAD(active_fds);
 static DECLARE_BITMAP(irqs_allocated, NR_IRQS);
+static bool irqs_suspended;
 
 static void irq_io_loop(struct irq_reg *irq, struct uml_pt_regs *regs)
 {
@@ -74,9 +81,65 @@ static void irq_io_loop(struct irq_reg *irq, struct uml_pt_regs *regs)
 	}
 }
 
-void sigio_handler_suspend(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
+#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
+static void irq_event_handler(struct time_travel_event *ev)
 {
-	/* nothing */
+	struct irq_reg *reg = container_of(ev, struct irq_reg, event);
+
+	/* do nothing if suspended - just to cause a wakeup */
+	if (irqs_suspended)
+		return;
+
+	generic_handle_irq(reg->irq);
+}
+
+static bool irq_do_timetravel_handler(struct irq_entry *entry,
+				      enum um_irq_type t)
+{
+	struct irq_reg *reg = &entry->reg[t];
+
+	if (!reg->timetravel_handler)
+		return false;
+
+	/* prevent nesting - we'll get it again later when we SIGIO ourselves */
+	if (reg->pending_on_resume)
+		return true;
+
+	reg->timetravel_handler(reg->irq, entry->fd, reg->id, &reg->event);
+
+	if (!reg->event.pending)
+		return false;
+
+	if (irqs_suspended)
+		reg->pending_on_resume = true;
+	return true;
+}
+#else
+static bool irq_do_timetravel_handler(struct irq_entry *entry,
+				      enum um_irq_type t)
+{
+	return false;
+}
+#endif
+
+static void sigio_reg_handler(int idx, struct irq_entry *entry, enum um_irq_type t,
+			      struct uml_pt_regs *regs)
+{
+	struct irq_reg *reg = &entry->reg[t];
+
+	if (!reg->events)
+		return;
+
+	if (os_epoll_triggered(idx, reg->events) <= 0)
+		return;
+
+	if (irq_do_timetravel_handler(entry, t))
+		return;
+
+	if (irqs_suspended)
+		return;
+
+	irq_io_loop(reg, regs);
 }
 
 void sigio_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
@@ -84,6 +147,9 @@ void sigio_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
 	struct irq_entry *irq_entry;
 	int n, i;
 
+	if (irqs_suspended && !um_irq_timetravel_handler_used())
+		return;
+
 	while (1) {
 		/* This is now lockless - epoll keeps back-referencesto the irqs
 		 * which have trigger it so there is no need to walk the irq
@@ -105,19 +171,13 @@ void sigio_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
 
 			irq_entry = os_epoll_get_data_pointer(i);
 
-			for (t = 0; t < NUM_IRQ_TYPES; t++) {
-				int events = irq_entry->reg[t].events;
-
-				if (!events)
-					continue;
-
-				if (os_epoll_triggered(i, events) > 0)
-					irq_io_loop(&irq_entry->reg[t], regs);
-			}
+			for (t = 0; t < NUM_IRQ_TYPES; t++)
+				sigio_reg_handler(i, irq_entry, t, regs);
 		}
 	}
 
-	free_irqs();
+	if (!irqs_suspended)
+		free_irqs();
 }
 
 static struct irq_entry *get_irq_entry_by_fd(int fd)
@@ -169,7 +229,9 @@ static void update_or_free_irq_entry(struct irq_entry *entry)
 		free_irq_entry(entry, false);
 }
 
-static int activate_fd(int irq, int fd, enum um_irq_type type, void *dev_id)
+static int activate_fd(int irq, int fd, enum um_irq_type type, void *dev_id,
+		       void (*timetravel_handler)(int, int, void *,
+						  struct time_travel_event *))
 {
 	struct irq_entry *irq_entry;
 	int err, events = os_event_mask(type);
@@ -206,6 +268,13 @@ static int activate_fd(int irq, int fd, enum um_irq_type type, void *dev_id)
 	irq_entry->reg[type].active = true;
 	irq_entry->reg[type].events = events;
 
+#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
+	if (um_irq_timetravel_handler_used()) {
+		irq_entry->reg[type].timetravel_handler = timetravel_handler;
+		irq_entry->reg[type].event.fn = irq_event_handler;
+	}
+#endif
+
 	WARN_ON(!update_irq_entry(irq_entry));
 	spin_unlock_irqrestore(&irq_lock, flags);
 
@@ -339,9 +408,12 @@ void um_free_irq(int irq, void *dev)
 }
 EXPORT_SYMBOL(um_free_irq);
 
-int um_request_irq(int irq, int fd, enum um_irq_type type,
-		   irq_handler_t handler, unsigned long irqflags,
-		   const char *devname, void *dev_id)
+static int
+_um_request_irq(int irq, int fd, enum um_irq_type type,
+		irq_handler_t handler, unsigned long irqflags,
+		const char *devname, void *dev_id,
+		void (*timetravel_handler)(int, int, void *,
+					   struct time_travel_event *))
 {
 	int err;
 
@@ -360,7 +432,7 @@ int um_request_irq(int irq, int fd, enum um_irq_type type,
 		return -ENOSPC;
 
 	if (fd != -1) {
-		err = activate_fd(irq, fd, type, dev_id);
+		err = activate_fd(irq, fd, type, dev_id, timetravel_handler);
 		if (err)
 			goto error;
 	}
@@ -374,20 +446,41 @@ error:
 	clear_bit(irq, irqs_allocated);
 	return err;
 }
+
+int um_request_irq(int irq, int fd, enum um_irq_type type,
+		   irq_handler_t handler, unsigned long irqflags,
+		   const char *devname, void *dev_id)
+{
+	return _um_request_irq(irq, fd, type, handler, irqflags,
+			       devname, dev_id, NULL);
+}
 EXPORT_SYMBOL(um_request_irq);
 
+#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
+int um_request_irq_tt(int irq, int fd, enum um_irq_type type,
+		      irq_handler_t handler, unsigned long irqflags,
+		      const char *devname, void *dev_id,
+		      void (*timetravel_handler)(int, int, void *,
+						 struct time_travel_event *))
+{
+	return _um_request_irq(irq, fd, type, handler, irqflags,
+			       devname, dev_id, timetravel_handler);
+}
+EXPORT_SYMBOL(um_request_irq_tt);
+#endif
+
 #ifdef CONFIG_PM_SLEEP
 void um_irqs_suspend(void)
 {
 	struct irq_entry *entry;
 	unsigned long flags;
 
-	sig_info[SIGIO] = sigio_handler_suspend;
+	irqs_suspended = true;
 
 	spin_lock_irqsave(&irq_lock, flags);
 	list_for_each_entry(entry, &active_fds, list) {
 		enum um_irq_type t;
-		bool wake = false;
+		bool clear = true;
 
 		for (t = 0; t < NUM_IRQ_TYPES; t++) {
 			if (!entry->reg[t].events)
@@ -400,13 +493,17 @@ void um_irqs_suspend(void)
 			 * any FDs that should be suspended.
 			 */
 			if (entry->reg[t].wakeup ||
-			    entry->reg[t].irq == SIGIO_WRITE_IRQ) {
-				wake = true;
+			    entry->reg[t].irq == SIGIO_WRITE_IRQ
+#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
+			    || entry->reg[t].timetravel_handler
+#endif
+			    ) {
+				clear = false;
 				break;
 			}
 		}
 
-		if (!wake) {
+		if (clear) {
 			entry->suspended = true;
 			os_clear_fd_async(entry->fd);
 			entry->sigio_workaround =
@@ -421,7 +518,31 @@ void um_irqs_resume(void)
 	struct irq_entry *entry;
 	unsigned long flags;
 
-	spin_lock_irqsave(&irq_lock, flags);
+
+	local_irq_save(flags);
+#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
+	/*
+	 * We don't need to lock anything here since we're in resume
+	 * and nothing else is running, but have disabled IRQs so we
+	 * don't try anything else with the interrupt list from there.
+	 */
+	list_for_each_entry(entry, &active_fds, list) {
+		enum um_irq_type t;
+
+		for (t = 0; t < NUM_IRQ_TYPES; t++) {
+			struct irq_reg *reg = &entry->reg[t];
+
+			if (reg->pending_on_resume) {
+				irq_enter();
+				generic_handle_irq(reg->irq);
+				irq_exit();
+				reg->pending_on_resume = false;
+			}
+		}
+	}
+#endif
+
+	spin_lock(&irq_lock);
 	list_for_each_entry(entry, &active_fds, list) {
 		if (entry->suspended) {
 			int err = os_set_fd_async(entry->fd);
@@ -437,7 +558,7 @@ void um_irqs_resume(void)
 	}
 	spin_unlock_irqrestore(&irq_lock, flags);
 
-	sig_info[SIGIO] = sigio_handler;
+	irqs_suspended = false;
 	send_sigio_to_self();
 }