diff mbox series

[06/17] xen: Port Xen event channel driver from mini-os

Message ID 20200701162959.9814-7-vicooodin@gmail.com
State Superseded
Delegated to: Tom Rini
Headers show
Series Add new board: Xen guest for ARM64 | expand

Commit Message

Anastasiia Lukianenko July 1, 2020, 4:29 p.m. UTC
From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>

Make required updates to run on u-boot. Strip functionality
not needed by U-boot.

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Anastasiia Lukianenko <anastasiia_lukianenko@epam.com>
---
 drivers/xen/Makefile     |   1 +
 drivers/xen/events.c     | 177 +++++++++++++++++++++++++++++++++++++++
 drivers/xen/hypervisor.c |   6 +-
 include/xen/events.h     |  47 +++++++++++
 4 files changed, 228 insertions(+), 3 deletions(-)
 create mode 100644 drivers/xen/events.c
 create mode 100644 include/xen/events.h

Comments

Simon Glass July 3, 2020, 3:50 a.m. UTC | #1
Hi,

On Wed, 1 Jul 2020 at 10:30, Anastasiia Lukianenko <vicooodin@gmail.com> wrote:
>
> From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
>
> Make required updates to run on u-boot. Strip functionality
> not needed by U-boot.
>
> Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
> Signed-off-by: Anastasiia Lukianenko <anastasiia_lukianenko@epam.com>
> ---
>  drivers/xen/Makefile     |   1 +
>  drivers/xen/events.c     | 177 +++++++++++++++++++++++++++++++++++++++
>  drivers/xen/hypervisor.c |   6 +-
>  include/xen/events.h     |  47 +++++++++++
>  4 files changed, 228 insertions(+), 3 deletions(-)
>  create mode 100644 drivers/xen/events.c
>  create mode 100644 include/xen/events.h
>
> diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
> index 1211bf2386..0ad35edefb 100644
> --- a/drivers/xen/Makefile
> +++ b/drivers/xen/Makefile
> @@ -3,3 +3,4 @@
>  # (C) Copyright 2020 EPAM Systems Inc.
>
>  obj-y += hypervisor.o
> +obj-y += events.o
> diff --git a/drivers/xen/events.c b/drivers/xen/events.c
> new file mode 100644
> index 0000000000..eddc6b6e29
> --- /dev/null
> +++ b/drivers/xen/events.c
> @@ -0,0 +1,177 @@
> +/* -*-  Mode:C; c-basic-offset:4; tab-width:4 -*-

SPDX is needed on files

> + ****************************************************************************
> + * (C) 2003 - Rolf Neugebauer - Intel Research Cambridge
> + * (C) 2005 - Grzegorz Milos - Intel Research Cambridge
> + * (C) 2020 - EPAM Systems Inc.
> + ****************************************************************************
> + *
> + *             File: events.c
> + *       Author: Rolf Neugebauer (neugebar@dcs.gla.ac.uk)
> + *      Changes: Grzegorz Milos (gm281@cam.ac.uk)
> + *
> + *             Date: Jul 2003, changes Jun 2005
> + *
> + * Environment: Xen Minimal OS
> + * Description: Deals with events received on event channels
> + *
> + ****************************************************************************

Can you drop these stars and use the normal U-Boot format?

> + */
> +#include <common.h>
> +#include <log.h>
> +
> +#include <asm/io.h>
> +#include <asm/xen/system.h>
> +
> +#include <xen/events.h>
> +#include <xen/hvm.h>
> +
> +#define NR_EVS 1024
> +
> +/* this represents a event handler. Chaining or sharing is not allowed */
> +typedef struct _ev_action_t {

Please don't use typedefs.

Also there should be comments on functions, particularly those in the
header file.

Are you trying to keep the source similar to an upstream version?

Regards,
SImon
Anastasiia Lukianenko July 3, 2020, 12:34 p.m. UTC | #2
Hello Simon,

On Thu, 2020-07-02 at 21:50 -0600, Simon Glass wrote:
> Hi,
> 
> On Wed, 1 Jul 2020 at 10:30, Anastasiia Lukianenko <
> vicooodin@gmail.com> wrote:
> > 
> > From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
> > 
> > Make required updates to run on u-boot. Strip functionality
> > not needed by U-boot.
> > 
> > Signed-off-by: Oleksandr Andrushchenko <
> > oleksandr_andrushchenko@epam.com>
> > Signed-off-by: Anastasiia Lukianenko <
> > anastasiia_lukianenko@epam.com>
> > ---
> >  drivers/xen/Makefile     |   1 +
> >  drivers/xen/events.c     | 177
> > +++++++++++++++++++++++++++++++++++++++
> >  drivers/xen/hypervisor.c |   6 +-
> >  include/xen/events.h     |  47 +++++++++++
> >  4 files changed, 228 insertions(+), 3 deletions(-)
> >  create mode 100644 drivers/xen/events.c
> >  create mode 100644 include/xen/events.h
> > 
> > diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
> > index 1211bf2386..0ad35edefb 100644
> > --- a/drivers/xen/Makefile
> > +++ b/drivers/xen/Makefile
> > @@ -3,3 +3,4 @@
> >  # (C) Copyright 2020 EPAM Systems Inc.
> > 
> >  obj-y += hypervisor.o
> > +obj-y += events.o
> > diff --git a/drivers/xen/events.c b/drivers/xen/events.c
> > new file mode 100644
> > index 0000000000..eddc6b6e29
> > --- /dev/null
> > +++ b/drivers/xen/events.c
> > @@ -0,0 +1,177 @@
> > +/* -*-  Mode:C; c-basic-offset:4; tab-width:4 -*-
> 
> SPDX is needed on files

Ok, will add.

> 
> > +
> > *******************************************************************
> > *********
> > + * (C) 2003 - Rolf Neugebauer - Intel Research Cambridge
> > + * (C) 2005 - Grzegorz Milos - Intel Research Cambridge
> > + * (C) 2020 - EPAM Systems Inc.
> > +
> > *******************************************************************
> > *********
> > + *
> > + *             File: events.c
> > + *       Author: Rolf Neugebauer (neugebar@dcs.gla.ac.uk)
> > + *      Changes: Grzegorz Milos (gm281@cam.ac.uk)
> > + *
> > + *             Date: Jul 2003, changes Jun 2005
> > + *
> > + * Environment: Xen Minimal OS
> > + * Description: Deals with events received on event channels
> > + *
> > +
> > *******************************************************************
> > *********
> 
> Can you drop these stars and use the normal U-Boot format?

Ok, will update all the files.

> 
> > + */
> > +#include <common.h>
> > +#include <log.h>
> > +
> > +#include <asm/io.h>
> > +#include <asm/xen/system.h>
> > +
> > +#include <xen/events.h>
> > +#include <xen/hvm.h>
> > +
> > +#define NR_EVS 1024
> > +
> > +/* this represents a event handler. Chaining or sharing is not
> > allowed */
> > +typedef struct _ev_action_t {
> 
> Please don't use typedefs.

Ok.

> 
> Also there should be comments on functions, particularly those in the
> header file.

Ok, will add comments in next version.

> 
> Are you trying to keep the source similar to an upstream version?

It seems that after this review we are stepping away from Mini-OS
anyway (like removing x86 code etc), so it is ok not to keep the source
close to the original code.

> 
> Regards,
> SImon

Regards,
Anastasiia
diff mbox series

Patch

diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index 1211bf2386..0ad35edefb 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -3,3 +3,4 @@ 
 # (C) Copyright 2020 EPAM Systems Inc.
 
 obj-y += hypervisor.o
+obj-y += events.o
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
new file mode 100644
index 0000000000..eddc6b6e29
--- /dev/null
+++ b/drivers/xen/events.c
@@ -0,0 +1,177 @@ 
+/* -*-  Mode:C; c-basic-offset:4; tab-width:4 -*-
+ ****************************************************************************
+ * (C) 2003 - Rolf Neugebauer - Intel Research Cambridge
+ * (C) 2005 - Grzegorz Milos - Intel Research Cambridge
+ * (C) 2020 - EPAM Systems Inc.
+ ****************************************************************************
+ *
+ *		File: events.c
+ *	  Author: Rolf Neugebauer (neugebar@dcs.gla.ac.uk)
+ *	 Changes: Grzegorz Milos (gm281@cam.ac.uk)
+ *
+ *		Date: Jul 2003, changes Jun 2005
+ *
+ * Environment: Xen Minimal OS
+ * Description: Deals with events received on event channels
+ *
+ ****************************************************************************
+ */
+#include <common.h>
+#include <log.h>
+
+#include <asm/io.h>
+#include <asm/xen/system.h>
+
+#include <xen/events.h>
+#include <xen/hvm.h>
+
+#define NR_EVS 1024
+
+/* this represents a event handler. Chaining or sharing is not allowed */
+typedef struct _ev_action_t {
+	evtchn_handler_t handler;
+	void *data;
+	u32 count;
+} ev_action_t;
+
+static ev_action_t ev_actions[NR_EVS];
+void default_handler(evtchn_port_t port, struct pt_regs *regs, void *data);
+
+static unsigned long bound_ports[NR_EVS / (8 * sizeof(unsigned long))];
+
+void unbind_all_ports(void)
+{
+	int i;
+	int cpu = 0;
+	struct shared_info *s = HYPERVISOR_shared_info;
+	struct vcpu_info *vcpu_info = &s->vcpu_info[cpu];
+
+	for (i = 0; i < NR_EVS; i++) {
+		if (test_and_clear_bit(i, bound_ports)) {
+			printf("port %d still bound!\n", i);
+			unbind_evtchn(i);
+		}
+	}
+	vcpu_info->evtchn_upcall_pending = 0;
+	vcpu_info->evtchn_pending_sel = 0;
+}
+
+/*
+ * Demux events to different handlers.
+ */
+int do_event(evtchn_port_t port, struct pt_regs *regs)
+{
+	ev_action_t  *action;
+
+	clear_evtchn(port);
+
+	if (port >= NR_EVS) {
+		printk("WARN: do_event(): Port number too large: %d\n", port);
+		return 1;
+	}
+
+	action = &ev_actions[port];
+	action->count++;
+
+	/* call the handler */
+	action->handler(port, regs, action->data);
+
+	return 1;
+}
+
+evtchn_port_t bind_evtchn(evtchn_port_t port, evtchn_handler_t handler,
+			  void *data)
+{
+	if (ev_actions[port].handler != default_handler)
+		printf("WARN: Handler for port %d already registered, replacing\n",
+		       port);
+
+	ev_actions[port].data = data;
+	wmb();
+	ev_actions[port].handler = handler;
+	synch_set_bit(port, bound_ports);
+
+	return port;
+}
+
+void unbind_evtchn(evtchn_port_t port)
+{
+	struct evtchn_close close;
+	int rc;
+
+	if (ev_actions[port].handler == default_handler)
+		printf("WARN: No handler for port %d when unbinding\n", port);
+	mask_evtchn(port);
+	clear_evtchn(port);
+
+	ev_actions[port].handler = default_handler;
+	wmb();
+	ev_actions[port].data = NULL;
+	synch_clear_bit(port, bound_ports);
+
+	close.port = port;
+	rc = HYPERVISOR_event_channel_op(EVTCHNOP_close, &close);
+	if (rc)
+		printf("WARN: close_port %d failed rc=%d. ignored\n", port, rc);
+}
+
+void default_handler(evtchn_port_t port, struct pt_regs *regs, void *ignore)
+{
+	debug("[Port %d] - event received\n", port);
+}
+
+/* Create a port available to the pal for exchanging notifications.
+ * Returns the result of the hypervisor call.
+ */
+
+/* Unfortunate confusion of terminology: the port is unbound as far
+ * as Xen is concerned, but we automatically bind a handler to it
+ * from inside mini-os.
+ */
+int evtchn_alloc_unbound(domid_t pal, evtchn_handler_t handler,
+			 void *data, evtchn_port_t *port)
+{
+	int rc;
+
+	struct evtchn_alloc_unbound op;
+
+	op.dom = DOMID_SELF;
+	op.remote_dom = pal;
+	rc = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound, &op);
+	if (rc) {
+		printf("ERROR: alloc_unbound failed with rc=%d", rc);
+		       return rc;
+	}
+	if (!handler)
+		handler = default_handler;
+	*port = bind_evtchn(op.port, handler, data);
+	return rc;
+}
+
+void eventchn_poll(void)
+{
+	do_hypervisor_callback(NULL);
+}
+
+/*
+ * Initially all events are without a handler and disabled
+ */
+void init_events(void)
+{
+	int i;
+
+	debug("%s\n", __func__);
+	/* initialize event handler */
+	for (i = 0; i < NR_EVS; i++) {
+		ev_actions[i].handler = default_handler;
+		mask_evtchn(i);
+	}
+}
+
+void fini_events(void)
+{
+	debug("%s\n", __func__);
+	/* Dealloc all events */
+	unbind_all_ports();
+}
+
diff --git a/drivers/xen/hypervisor.c b/drivers/xen/hypervisor.c
index 5883285142..975e552242 100644
--- a/drivers/xen/hypervisor.c
+++ b/drivers/xen/hypervisor.c
@@ -37,6 +37,7 @@ 
 #include <linux/bug.h>
 
 #include <xen/hvm.h>
+#include <xen/events.h>
 #include <xen/interface/memory.h>
 
 #define active_evtchns(cpu, sh, idx)	\
@@ -198,9 +199,7 @@  void do_hypervisor_callback(struct pt_regs *regs)
 			l2 &= ~(1UL << l2i);
 
 			port = (l1i * (sizeof(unsigned long) * 8)) + l2i;
-			/* TODO: handle new event: do_event(port, regs); */
-			/* Suppress -Wunused-but-set-variable */
-			(void)(port);
+			do_event(port, regs);
 		}
 	}
 
@@ -273,5 +272,6 @@  void xen_init(void)
 	debug("%s\n", __func__);
 
 	map_shared_info(NULL);
+	init_events();
 }
 
diff --git a/include/xen/events.h b/include/xen/events.h
new file mode 100644
index 0000000000..63abdf426b
--- /dev/null
+++ b/include/xen/events.h
@@ -0,0 +1,47 @@ 
+/* -*-  Mode:C; c-basic-offset:4; tab-width:4 -*-
+ ****************************************************************************
+ * (C) 2003 - Rolf Neugebauer - Intel Research Cambridge
+ * (C) 2005 - Grzegorz Milos - Intel Reseach Cambridge
+ * (C) 2020 - EPAM Systems Inc.
+ ****************************************************************************
+ *
+ *        File: events.h
+ *      Author: Rolf Neugebauer (neugebar@dcs.gla.ac.uk)
+ *     Changes: Grzegorz Milos (gm281@cam.ac.uk)
+ *
+ *        Date: Jul 2003, changes Jun 2005
+ *
+ * Environment: Xen Minimal OS
+ * Description: Deals with events on the event channels
+ *
+ ****************************************************************************
+ */
+
+#ifndef _EVENTS_H_
+#define _EVENTS_H_
+
+#include <asm/xen/hypercall.h>
+#include <xen/interface/event_channel.h>
+
+typedef void (*evtchn_handler_t)(evtchn_port_t, struct pt_regs *, void *);
+
+void init_events(void);
+void fini_events(void);
+
+int do_event(evtchn_port_t port, struct pt_regs *regs);
+void unbind_evtchn(evtchn_port_t port);
+void unbind_all_ports(void);
+int evtchn_alloc_unbound(domid_t pal, evtchn_handler_t handler,
+			 void *data, evtchn_port_t *port);
+
+static inline int notify_remote_via_evtchn(evtchn_port_t port)
+{
+	struct evtchn_send op;
+
+	op.port = port;
+	return HYPERVISOR_event_channel_op(EVTCHNOP_send, &op);
+}
+
+void eventchn_poll(void);
+
+#endif /* _EVENTS_H_ */