kern/src/trap.c - upstream - Git at Google

 /* Copyright (c) 2012 The Regents of the University of California
  * Barret Rhoden <brho@cs.berkeley.edu>
  * See LICENSE for details.
  *
  * Arch-independent trap handling and kernel messaging */

 #include <arch/arch.h>
 #include <smp.h>
 #include <trap.h>
 #include <stdio.h>
 #include <slab.h>
 #include <assert.h>
 #include <kdebug.h>
 #include <kmalloc.h>

 void reflect_unhandled_trap(unsigned int trap_nr, unsigned int err,
                             unsigned long aux)
 {
 	uint32_t coreid = core_id();
 	struct per_cpu_info *pcpui = &per_cpu_info[coreid];
 	struct proc *p = pcpui->cur_proc;
 	uint32_t vcoreid = pcpui->owning_vcoreid;
 	struct preempt_data *vcpd = &p->procdata->vcore_preempt_data[vcoreid];
 	struct hw_trapframe *hw_tf = &pcpui->cur_ctx->tf.hw_tf;
 	assert(p);
 	assert(pcpui->cur_ctx && (pcpui->cur_ctx->type == ROS_HW_CTX));
 	if (!(p->procinfo->is_mcp)) {
 		printk("Unhandled SCP trap\n");
 		goto error_out;
 	}
 	if (vcpd->notif_disabled) {
 		printk("Unhandled MCP trap in vcore context\n");
 		goto error_out;
 	}
 	/* need to store trap_nr, err code, and aux into the tf so that it can get
 	 * extracted on the other end, and we need to flag the TF in some way so we
 	 * can tell it was reflected.  for example, on a PF, we need some number (14
 	 * on x86), the prot violation (write, read, etc), and the virt addr (aux).
 	 * parlib will know how to extract this info. */
 	__arch_reflect_trap_hwtf(hw_tf, trap_nr, err, aux);
 	/* the guts of a __notify */
 	vcpd->notif_disabled = TRUE;
 	vcpd->uthread_ctx = *pcpui->cur_ctx;
 	memset(pcpui->cur_ctx, 0, sizeof(struct user_context));
 	proc_init_ctx(pcpui->cur_ctx, vcoreid, p->env_entry,
 	              vcpd->transition_stack, vcpd->vcore_tls_desc);
 	return;
 error_out:
 	print_trapframe(hw_tf);
 	enable_irq();
 	printk("err 0x%x (for PFs: User 4, Wr 2, Rd 1), aux %p\n", err, aux);
 	debug_addr_proc(p, get_hwtf_pc(hw_tf));
 	print_vmrs(p);
 	proc_destroy(p);
 }

 struct kmem_cache *kernel_msg_cache;

 void kernel_msg_init(void)
 {
 	kernel_msg_cache = kmem_cache_create("kernel_msgs",
 	                   sizeof(struct kernel_message), ARCH_CL_SIZE, 0, 0, 0);
 }

 uint32_t send_kernel_message(uint32_t dst, amr_t pc, long arg0, long arg1,
                              long arg2, int type)
 {
 	kernel_message_t *k_msg;
 	assert(pc);
 	// note this will be freed on the destination core
 	k_msg = kmem_cache_alloc(kernel_msg_cache, 0);
 	k_msg->srcid = core_id();
 	k_msg->dstid = dst;
 	k_msg->pc = pc;
 	k_msg->arg0 = arg0;
 	k_msg->arg1 = arg1;
 	k_msg->arg2 = arg2;
 	switch (type) {
 		case KMSG_IMMEDIATE:
 			spin_lock_irqsave(&per_cpu_info[dst].immed_amsg_lock);
 			STAILQ_INSERT_TAIL(&per_cpu_info[dst].immed_amsgs, k_msg, link);
 			spin_unlock_irqsave(&per_cpu_info[dst].immed_amsg_lock);
 			break;
 		case KMSG_ROUTINE:
 			spin_lock_irqsave(&per_cpu_info[dst].routine_amsg_lock);
 			STAILQ_INSERT_TAIL(&per_cpu_info[dst].routine_amsgs, k_msg, link);
 			spin_unlock_irqsave(&per_cpu_info[dst].routine_amsg_lock);
 			break;
 		default:
 			panic("Unknown type of kernel message!");
 	}
 	/* since we touched memory the other core will touch (the lock), we don't
 	 * need an wmb_f() */
 	/* if we're sending a routine message locally, we don't want/need an IPI */
 	if ((dst != k_msg->srcid) || (type == KMSG_IMMEDIATE))
 		send_ipi(dst, I_KERNEL_MSG);
 	return 0;
 }

 /* Kernel message IPI/IRQ handler.
  *
  * This processes immediate messages, and that's it (it used to handle routines
  * too, if it came in from userspace).  Routine messages will get processed when
  * the kernel has a chance (right before popping to userspace or in smp_idle
  * before halting).
  *
  * Note that all of this happens from interrupt context, and interrupts are
  * disabled. */
 void handle_kmsg_ipi(struct hw_trapframe *hw_tf, void *data)
 {
 	struct per_cpu_info *pcpui = &per_cpu_info[core_id()];
 	struct kernel_message *kmsg_i, *temp;
 	/* Avoid locking if the list appears empty (lockless peek is okay) */
 	if (STAILQ_EMPTY(&pcpui->immed_amsgs))
 		return;
 	/* The lock serves as a cmb to force a re-read of the head of the list */
 	spin_lock_irqsave(&pcpui->immed_amsg_lock);
 	STAILQ_FOREACH_SAFE(kmsg_i, &pcpui->immed_amsgs, link, temp) {
 		pcpui_trace_kmsg(pcpui, (uintptr_t)kmsg_i->pc);
 		kmsg_i->pc(kmsg_i->srcid, kmsg_i->arg0, kmsg_i->arg1, kmsg_i->arg2);
 		STAILQ_REMOVE(&pcpui->immed_amsgs, kmsg_i, kernel_message, link);
 		kmem_cache_free(kernel_msg_cache, (void*)kmsg_i);
 	}
 	spin_unlock_irqsave(&pcpui->immed_amsg_lock);
 }

 bool has_routine_kmsg(void)
 {
 	struct per_cpu_info *pcpui = &per_cpu_info[core_id()];
 	/* lockless peek */
 	return !STAILQ_EMPTY(&pcpui->routine_amsgs);
 }

 /* Helper function, gets the next routine KMSG (RKM).  Returns 0 if the list was
  * empty. */
 static kernel_message_t *get_next_rkmsg(struct per_cpu_info *pcpui)
 {
 	struct kernel_message *kmsg;
 	/* Avoid locking if the list appears empty (lockless peek is okay) */
 	if (STAILQ_EMPTY(&pcpui->routine_amsgs))
 		return 0;
 	/* The lock serves as a cmb to force a re-read of the head of the list.
 	 * IRQs are disabled by our caller. */
 	spin_lock(&pcpui->routine_amsg_lock);
 	kmsg = STAILQ_FIRST(&pcpui->routine_amsgs);
 	if (kmsg)
 		STAILQ_REMOVE_HEAD(&pcpui->routine_amsgs, link);
 	spin_unlock(&pcpui->routine_amsg_lock);
 	return kmsg;
 }

 /* Runs routine kernel messages.  This might not return.  In the past, this
  * would also run immediate messages, but this is unnecessary.  Immediates will
  * run whenever we reenable IRQs.  We could have some sort of ordering or
  * guarantees between KMSG classes, but that's not particularly useful at this
  * point.
  *
  * Note this runs from normal context, with interruptes disabled.  However, a
  * particular RKM could enable interrupts - for instance __launch_kthread() will
  * restore an old kthread that may have had IRQs on. */
 void process_routine_kmsg(void)
 {
 	uint32_t pcoreid = core_id();
 	struct per_cpu_info *pcpui = &per_cpu_info[pcoreid];
 	struct kernel_message msg_cp, *kmsg;

 	/* Important that callers have IRQs disabled.  When sending cross-core RKMs,
 	 * the IPI is used to keep the core from going to sleep - even though RKMs
 	 * aren't handled in the kmsg handler.  Check smp_idle() for more info. */
 	assert(!irq_is_enabled());
 	while ((kmsg = get_next_rkmsg(pcpui))) {
 		/* Copy in, and then free, in case we don't return */
 		msg_cp = *kmsg;
 		kmem_cache_free(kernel_msg_cache, (void*)kmsg);
 		assert(msg_cp.dstid == pcoreid);	/* caught a brutal bug with this */
 		set_rkmsg(pcpui);					/* we're now in early RKM ctx */
 		/* The kmsg could block.  If it does, we want the kthread code to know
 		 * it's not running on behalf of a process, and we're actually spawning
 		 * a kernel task.  While we do have a syscall that does work in an RKM
 		 * (change_to), it's not really the rest of the syscall context. */
 		pcpui->cur_kthread->is_ktask = TRUE;
 		pcpui_trace_kmsg(pcpui, (uintptr_t)msg_cp.pc);
 		msg_cp.pc(msg_cp.srcid, msg_cp.arg0, msg_cp.arg1, msg_cp.arg2);
 		/* And if we make it back, be sure to unset this.  If we never return,
 		 * but the kthread exits via some other way (smp_idle()), then
 		 * smp_idle() will deal with the flag.  The default state is "off".  For
 		 * an example of an RKM that does this, check out the
 		 * monitor->mon_bin_run.  Finally, if the kthread gets swapped out of
 		 * pcpui, such as in __launch_kthread(), the next time the kthread is
 		 * reused, is_ktask will be reset. */
 		pcpui->cur_kthread->is_ktask = FALSE;
 		/* If we aren't still in early RKM, it is because the KMSG blocked
 		 * (thus leaving early RKM, finishing in default context) and then
 		 * returned.  This is a 'detached' RKM.  Must idle in this scenario,
 		 * since we might have migrated or otherwise weren't meant to PRKM
 		 * (can't return twice).  Also note that this may involve a core
 		 * migration, so we need to reread pcpui.*/
 		cmb();
 		pcpui = &per_cpu_info[core_id()];
 		if (!in_early_rkmsg_ctx(pcpui))
 			smp_idle();
 		clear_rkmsg(pcpui);
 		/* Some RKMs might turn on interrupts (perhaps in the future) and then
 		 * return. */
 		disable_irq();
 	}
 }

 /* extremely dangerous and racy: prints out the immed and routine kmsgs for a
  * specific core (so possibly remotely) */
 void print_kmsgs(uint32_t coreid)
 {
 	struct per_cpu_info *pcpui = &per_cpu_info[coreid];
 	void __print_kmsgs(struct kernel_msg_list *list, char *type)
 	{
 		char *fn_name;
 		struct kernel_message *kmsg_i;
 		STAILQ_FOREACH(kmsg_i, list, link) {
 			fn_name = get_fn_name((long)kmsg_i->pc);
 			printk("%s KMSG on %d from %d to run %p(%s)\n", type,
 			       kmsg_i->dstid, kmsg_i->srcid, kmsg_i->pc, fn_name);
 			kfree(fn_name);
 		}
 	}
 	__print_kmsgs(&pcpui->immed_amsgs, "Immedte");
 	__print_kmsgs(&pcpui->routine_amsgs, "Routine");
 }

 /* Debugging stuff */
 void kmsg_queue_stat(void)
 {
 	struct kernel_message *kmsg;
 	bool immed_emp, routine_emp;
 	for (int i = 0; i < num_cpus; i++) {
 		spin_lock_irqsave(&per_cpu_info[i].immed_amsg_lock);
 		immed_emp = STAILQ_EMPTY(&per_cpu_info[i].immed_amsgs);
 		spin_unlock_irqsave(&per_cpu_info[i].immed_amsg_lock);
 		spin_lock_irqsave(&per_cpu_info[i].routine_amsg_lock);
 		routine_emp = STAILQ_EMPTY(&per_cpu_info[i].routine_amsgs);
 		spin_unlock_irqsave(&per_cpu_info[i].routine_amsg_lock);
 		printk("Core %d's immed_emp: %d, routine_emp %d\n", i, immed_emp,
                routine_emp);
 		if (!immed_emp) {
 			kmsg = STAILQ_FIRST(&per_cpu_info[i].immed_amsgs);
 			printk("Immed msg on core %d:\n", i);
 			printk("\tsrc:  %d\n", kmsg->srcid);
 			printk("\tdst:  %d\n", kmsg->dstid);
 			printk("\tpc:   %p\n", kmsg->pc);
 			printk("\targ0: %p\n", kmsg->arg0);
 			printk("\targ1: %p\n", kmsg->arg1);
 			printk("\targ2: %p\n", kmsg->arg2);
 		}
 		if (!routine_emp) {
 			kmsg = STAILQ_FIRST(&per_cpu_info[i].routine_amsgs);
 			printk("Routine msg on core %d:\n", i);
 			printk("\tsrc:  %d\n", kmsg->srcid);
 			printk("\tdst:  %d\n", kmsg->dstid);
 			printk("\tpc:   %p\n", kmsg->pc);
 			printk("\targ0: %p\n", kmsg->arg0);
 			printk("\targ1: %p\n", kmsg->arg1);
 			printk("\targ2: %p\n", kmsg->arg2);
 		}

 	}
 }

 void print_kctx_depths(const char *str)
 {
 	uint32_t coreid = core_id();
 	struct per_cpu_info *pcpui = &per_cpu_info[coreid];

 	if (!str)
 		str = "(none)";
 	printk("%s: Core %d, irq depth %d, ktrap depth %d, irqon %d\n", str, coreid,
 	       irq_depth(pcpui), ktrap_depth(pcpui), irq_is_enabled());
 }

 void print_user_ctx(struct user_context *ctx)
 {
 	if (ctx->type == ROS_SW_CTX)
 		print_swtrapframe(&ctx->tf.sw_tf);
 	else if (ctx->type == ROS_HW_CTX)
 		print_trapframe(&ctx->tf.hw_tf);
 	else
 		printk("Bad TF %p type %d!\n", ctx, ctx->type);
 }
	/* Copyright (c) 2012 The Regents of the University of California
	* Barret Rhoden <brho@cs.berkeley.edu>
	* See LICENSE for details.
	*
	* Arch-independent trap handling and kernel messaging */

	#include <arch/arch.h>
	#include <smp.h>
	#include <trap.h>
	#include <stdio.h>
	#include <slab.h>
	#include <assert.h>
	#include <kdebug.h>
	#include <kmalloc.h>

	void reflect_unhandled_trap(unsigned int trap_nr, unsigned int err,
	unsigned long aux)
	{
	uint32_t coreid = core_id();
	struct per_cpu_info *pcpui = &per_cpu_info[coreid];
	struct proc *p = pcpui->cur_proc;
	uint32_t vcoreid = pcpui->owning_vcoreid;
	struct preempt_data *vcpd = &p->procdata->vcore_preempt_data[vcoreid];
	struct hw_trapframe *hw_tf = &pcpui->cur_ctx->tf.hw_tf;
	assert(p);
	assert(pcpui->cur_ctx && (pcpui->cur_ctx->type == ROS_HW_CTX));
	if (!(p->procinfo->is_mcp)) {
	printk("Unhandled SCP trap\n");
	goto error_out;
	}
	if (vcpd->notif_disabled) {
	printk("Unhandled MCP trap in vcore context\n");
	goto error_out;
	}
	/* need to store trap_nr, err code, and aux into the tf so that it can get
	* extracted on the other end, and we need to flag the TF in some way so we
	* can tell it was reflected. for example, on a PF, we need some number (14
	* on x86), the prot violation (write, read, etc), and the virt addr (aux).
	* parlib will know how to extract this info. */
	__arch_reflect_trap_hwtf(hw_tf, trap_nr, err, aux);
	/* the guts of a __notify */
	vcpd->notif_disabled = TRUE;
	vcpd->uthread_ctx = *pcpui->cur_ctx;
	memset(pcpui->cur_ctx, 0, sizeof(struct user_context));
	proc_init_ctx(pcpui->cur_ctx, vcoreid, p->env_entry,
	vcpd->transition_stack, vcpd->vcore_tls_desc);
	return;
	error_out:
	print_trapframe(hw_tf);
	enable_irq();
	printk("err 0x%x (for PFs: User 4, Wr 2, Rd 1), aux %p\n", err, aux);
	debug_addr_proc(p, get_hwtf_pc(hw_tf));
	print_vmrs(p);
	proc_destroy(p);
	}

	struct kmem_cache *kernel_msg_cache;

	void kernel_msg_init(void)
	{
	kernel_msg_cache = kmem_cache_create("kernel_msgs",
	sizeof(struct kernel_message), ARCH_CL_SIZE, 0, 0, 0);
	}

	uint32_t send_kernel_message(uint32_t dst, amr_t pc, long arg0, long arg1,
	long arg2, int type)
	{
	kernel_message_t *k_msg;
	assert(pc);
	// note this will be freed on the destination core
	k_msg = kmem_cache_alloc(kernel_msg_cache, 0);
	k_msg->srcid = core_id();
	k_msg->dstid = dst;
	k_msg->pc = pc;
	k_msg->arg0 = arg0;
	k_msg->arg1 = arg1;
	k_msg->arg2 = arg2;
	switch (type) {
	case KMSG_IMMEDIATE:
	spin_lock_irqsave(&per_cpu_info[dst].immed_amsg_lock);
	STAILQ_INSERT_TAIL(&per_cpu_info[dst].immed_amsgs, k_msg, link);
	spin_unlock_irqsave(&per_cpu_info[dst].immed_amsg_lock);
	break;
	case KMSG_ROUTINE:
	spin_lock_irqsave(&per_cpu_info[dst].routine_amsg_lock);
	STAILQ_INSERT_TAIL(&per_cpu_info[dst].routine_amsgs, k_msg, link);
	spin_unlock_irqsave(&per_cpu_info[dst].routine_amsg_lock);
	break;
	default:
	panic("Unknown type of kernel message!");
	}
	/* since we touched memory the other core will touch (the lock), we don't
	* need an wmb_f() */
	/* if we're sending a routine message locally, we don't want/need an IPI */
	if ((dst != k_msg->srcid) \|\| (type == KMSG_IMMEDIATE))
	send_ipi(dst, I_KERNEL_MSG);
	return 0;
	}

	/* Kernel message IPI/IRQ handler.
	*
	* This processes immediate messages, and that's it (it used to handle routines
	* too, if it came in from userspace). Routine messages will get processed when
	* the kernel has a chance (right before popping to userspace or in smp_idle
	* before halting).
	*
	* Note that all of this happens from interrupt context, and interrupts are
	* disabled. */
	void handle_kmsg_ipi(struct hw_trapframe hw_tf, void data)
	{
	struct per_cpu_info *pcpui = &per_cpu_info[core_id()];
	struct kernel_message kmsg_i, temp;
	/* Avoid locking if the list appears empty (lockless peek is okay) */
	if (STAILQ_EMPTY(&pcpui->immed_amsgs))
	return;
	/* The lock serves as a cmb to force a re-read of the head of the list */
	spin_lock_irqsave(&pcpui->immed_amsg_lock);
	STAILQ_FOREACH_SAFE(kmsg_i, &pcpui->immed_amsgs, link, temp) {
	pcpui_trace_kmsg(pcpui, (uintptr_t)kmsg_i->pc);
	kmsg_i->pc(kmsg_i->srcid, kmsg_i->arg0, kmsg_i->arg1, kmsg_i->arg2);
	STAILQ_REMOVE(&pcpui->immed_amsgs, kmsg_i, kernel_message, link);
	kmem_cache_free(kernel_msg_cache, (void*)kmsg_i);
	}
	spin_unlock_irqsave(&pcpui->immed_amsg_lock);
	}

	bool has_routine_kmsg(void)
	{
	struct per_cpu_info *pcpui = &per_cpu_info[core_id()];
	/* lockless peek */
	return !STAILQ_EMPTY(&pcpui->routine_amsgs);
	}

	/* Helper function, gets the next routine KMSG (RKM). Returns 0 if the list was
	* empty. */
	static kernel_message_t get_next_rkmsg(struct per_cpu_info pcpui)
	{
	struct kernel_message *kmsg;
	/* Avoid locking if the list appears empty (lockless peek is okay) */
	if (STAILQ_EMPTY(&pcpui->routine_amsgs))
	return 0;
	/* The lock serves as a cmb to force a re-read of the head of the list.
	* IRQs are disabled by our caller. */
	spin_lock(&pcpui->routine_amsg_lock);
	kmsg = STAILQ_FIRST(&pcpui->routine_amsgs);
	if (kmsg)
	STAILQ_REMOVE_HEAD(&pcpui->routine_amsgs, link);
	spin_unlock(&pcpui->routine_amsg_lock);
	return kmsg;
	}

	/* Runs routine kernel messages. This might not return. In the past, this
	* would also run immediate messages, but this is unnecessary. Immediates will
	* run whenever we reenable IRQs. We could have some sort of ordering or
	* guarantees between KMSG classes, but that's not particularly useful at this
	* point.
	*
	* Note this runs from normal context, with interruptes disabled. However, a
	* particular RKM could enable interrupts - for instance __launch_kthread() will
	* restore an old kthread that may have had IRQs on. */
	void process_routine_kmsg(void)
	{
	uint32_t pcoreid = core_id();
	struct per_cpu_info *pcpui = &per_cpu_info[pcoreid];
	struct kernel_message msg_cp, *kmsg;

	/* Important that callers have IRQs disabled. When sending cross-core RKMs,
	* the IPI is used to keep the core from going to sleep - even though RKMs
	* aren't handled in the kmsg handler. Check smp_idle() for more info. */
	assert(!irq_is_enabled());
	while ((kmsg = get_next_rkmsg(pcpui))) {
	/* Copy in, and then free, in case we don't return */
	msg_cp = *kmsg;
	kmem_cache_free(kernel_msg_cache, (void*)kmsg);
	assert(msg_cp.dstid == pcoreid); /* caught a brutal bug with this */
	set_rkmsg(pcpui); /* we're now in early RKM ctx */
	/* The kmsg could block. If it does, we want the kthread code to know
	* it's not running on behalf of a process, and we're actually spawning
	* a kernel task. While we do have a syscall that does work in an RKM
	* (change_to), it's not really the rest of the syscall context. */
	pcpui->cur_kthread->is_ktask = TRUE;
	pcpui_trace_kmsg(pcpui, (uintptr_t)msg_cp.pc);
	msg_cp.pc(msg_cp.srcid, msg_cp.arg0, msg_cp.arg1, msg_cp.arg2);
	/* And if we make it back, be sure to unset this. If we never return,
	* but the kthread exits via some other way (smp_idle()), then
	* smp_idle() will deal with the flag. The default state is "off". For
	* an example of an RKM that does this, check out the
	* monitor->mon_bin_run. Finally, if the kthread gets swapped out of
	* pcpui, such as in __launch_kthread(), the next time the kthread is
	* reused, is_ktask will be reset. */
	pcpui->cur_kthread->is_ktask = FALSE;
	/* If we aren't still in early RKM, it is because the KMSG blocked
	* (thus leaving early RKM, finishing in default context) and then
	* returned. This is a 'detached' RKM. Must idle in this scenario,
	* since we might have migrated or otherwise weren't meant to PRKM
	* (can't return twice). Also note that this may involve a core
	* migration, so we need to reread pcpui.*/
	cmb();
	pcpui = &per_cpu_info[core_id()];
	if (!in_early_rkmsg_ctx(pcpui))
	smp_idle();
	clear_rkmsg(pcpui);
	/* Some RKMs might turn on interrupts (perhaps in the future) and then
	* return. */
	disable_irq();
	}
	}

	/* extremely dangerous and racy: prints out the immed and routine kmsgs for a
	* specific core (so possibly remotely) */
	void print_kmsgs(uint32_t coreid)
	{
	struct per_cpu_info *pcpui = &per_cpu_info[coreid];
	void __print_kmsgs(struct kernel_msg_list list, char type)
	{
	char *fn_name;
	struct kernel_message *kmsg_i;
	STAILQ_FOREACH(kmsg_i, list, link) {
	fn_name = get_fn_name((long)kmsg_i->pc);
	printk("%s KMSG on %d from %d to run %p(%s)\n", type,
	kmsg_i->dstid, kmsg_i->srcid, kmsg_i->pc, fn_name);
	kfree(fn_name);
	}
	}
	__print_kmsgs(&pcpui->immed_amsgs, "Immedte");
	__print_kmsgs(&pcpui->routine_amsgs, "Routine");
	}

	/* Debugging stuff */
	void kmsg_queue_stat(void)
	{
	struct kernel_message *kmsg;
	bool immed_emp, routine_emp;
	for (int i = 0; i < num_cpus; i++) {
	spin_lock_irqsave(&per_cpu_info[i].immed_amsg_lock);
	immed_emp = STAILQ_EMPTY(&per_cpu_info[i].immed_amsgs);
	spin_unlock_irqsave(&per_cpu_info[i].immed_amsg_lock);
	spin_lock_irqsave(&per_cpu_info[i].routine_amsg_lock);
	routine_emp = STAILQ_EMPTY(&per_cpu_info[i].routine_amsgs);
	spin_unlock_irqsave(&per_cpu_info[i].routine_amsg_lock);
	printk("Core %d's immed_emp: %d, routine_emp %d\n", i, immed_emp,
	routine_emp);
	if (!immed_emp) {
	kmsg = STAILQ_FIRST(&per_cpu_info[i].immed_amsgs);
	printk("Immed msg on core %d:\n", i);
	printk("\tsrc: %d\n", kmsg->srcid);
	printk("\tdst: %d\n", kmsg->dstid);
	printk("\tpc: %p\n", kmsg->pc);
	printk("\targ0: %p\n", kmsg->arg0);
	printk("\targ1: %p\n", kmsg->arg1);
	printk("\targ2: %p\n", kmsg->arg2);
	}
	if (!routine_emp) {
	kmsg = STAILQ_FIRST(&per_cpu_info[i].routine_amsgs);
	printk("Routine msg on core %d:\n", i);
	printk("\tsrc: %d\n", kmsg->srcid);
	printk("\tdst: %d\n", kmsg->dstid);
	printk("\tpc: %p\n", kmsg->pc);
	printk("\targ0: %p\n", kmsg->arg0);
	printk("\targ1: %p\n", kmsg->arg1);
	printk("\targ2: %p\n", kmsg->arg2);
	}

	}
	}

	void print_kctx_depths(const char *str)
	{
	uint32_t coreid = core_id();
	struct per_cpu_info *pcpui = &per_cpu_info[coreid];

	if (!str)
	str = "(none)";
	printk("%s: Core %d, irq depth %d, ktrap depth %d, irqon %d\n", str, coreid,
	irq_depth(pcpui), ktrap_depth(pcpui), irq_is_enabled());
	}

	void print_user_ctx(struct user_context *ctx)
	{
	if (ctx->type == ROS_SW_CTX)
	print_swtrapframe(&ctx->tf.sw_tf);
	else if (ctx->type == ROS_HW_CTX)
	print_trapframe(&ctx->tf.hw_tf);
	else
	printk("Bad TF %p type %d!\n", ctx, ctx->type);
	}