1
0
mirror of https://git.FreeBSD.org/src.git synced 2024-12-14 10:09:48 +00:00

xen: allow to register event channels without handlers

This is needed by the event channel user-space device, that requires
registering event channels without unmasking them. intr_add_handler
will unconditionally unmask the event channel, so we avoid calling it
if no filter/handler is provided, and then the user will be in charge
of calling it when ready.

In order to do this, we need to change the opaque type
xen_intr_handle_t to contain the event channel port instead of the
opaque cookie returned by intr_add_handler, since now registration of
event channels without handlers are allowed. The cookie will now be
stored inside of the private xenisrc struct. Also, introduce a new
function called xen_intr_add_handler that allows adding a
filter/handler after the event channel has been registered.

Sponsored by: Citrix Systems R&D

x86/xen/xen_intr.c:
 - Leave the event channel without a handler if no filter/handler is
   provided to xen_intr_bind_isrc.
 - Don't perform an evtchn_mask_port, intr_add_handler will already do
   it.
 - Change the opaque type xen_intr_handle_t to contain a pointer to
   the event channel port number, and make the necessary changes to
   related functions.
 - Introduce a new function called xen_intr_add_handler that can be
   used to add filter/handlers to an event channel after registration.

xen/xen_intr.h:
 - Add prototype of xen_intr_add_handler.
This commit is contained in:
Roger Pau Monné 2014-10-22 16:51:52 +00:00
parent b2537024be
commit 6d54cab1fe
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=273473
2 changed files with 76 additions and 17 deletions

View File

@ -110,10 +110,11 @@ DPCPU_DEFINE(struct xen_intr_pcpu_data, xen_intr_pcpu) = {
DPCPU_DECLARE(struct vcpu_info *, vcpu_info);
#define is_valid_evtchn(x) ((x) != 0)
#define XEN_EEXIST 17 /* Xen "already exists" error */
#define XEN_ALLOCATE_VECTOR 0 /* Allocate a vector for this event channel */
#define XEN_INVALID_EVTCHN 0 /* Invalid event channel */
#define is_valid_evtchn(x) ((x) != XEN_INVALID_EVTCHN)
struct xenisrc {
struct intsrc xi_intsrc;
@ -123,6 +124,7 @@ struct xenisrc {
evtchn_port_t xi_port;
int xi_pirq;
int xi_virq;
void *xi_cookie;
u_int xi_close:1; /* close on unbind? */
u_int xi_shared:1; /* Shared with other domains. */
u_int xi_activehi:1;
@ -365,6 +367,7 @@ xen_intr_release_isrc(struct xenisrc *isrc)
isrc->xi_cpu = 0;
isrc->xi_type = EVTCHN_TYPE_UNBOUND;
isrc->xi_port = 0;
isrc->xi_cookie = NULL;
mtx_unlock(&xen_intr_isrc_lock);
return (0);
}
@ -419,17 +422,26 @@ xen_intr_bind_isrc(struct xenisrc **isrcp, evtchn_port_t local_port,
xen_intr_port_to_isrc[local_port] = isrc;
mtx_unlock(&xen_intr_isrc_lock);
error = intr_add_handler(device_get_nameunit(intr_owner),
isrc->xi_vector, filter, handler, arg,
flags|INTR_EXCL, port_handlep);
/* Assign the opaque handler (the event channel port) */
*port_handlep = &isrc->xi_port;
if (filter == NULL && handler == NULL) {
/*
* No filter/handler provided, leave the event channel
* masked and without a valid handler, the caller is
* in charge of setting that up.
*/
*isrcp = isrc;
return (0);
}
error = xen_intr_add_handler(intr_owner, filter, handler, arg, flags,
*port_handlep);
if (error != 0) {
device_printf(intr_owner,
"xen_intr_bind_irq: intr_add_handler failed\n");
xen_intr_release_isrc(isrc);
return (error);
}
*isrcp = isrc;
evtchn_unmask_port(local_port);
return (0);
}
@ -446,13 +458,16 @@ xen_intr_bind_isrc(struct xenisrc **isrcp, evtchn_port_t local_port,
static struct xenisrc *
xen_intr_isrc(xen_intr_handle_t handle)
{
struct intr_handler *ih;
evtchn_port_t port;
ih = handle;
if (ih == NULL || ih->ih_event == NULL)
if (handle == NULL)
return (NULL);
return (ih->ih_event->ie_source);
port = *(evtchn_port_t *)handle;
if (!is_valid_evtchn(port) || port >= NR_EVENT_CHANNELS)
return (NULL);
return (xen_intr_port_to_isrc[port]);
}
/**
@ -1446,22 +1461,24 @@ xen_intr_describe(xen_intr_handle_t port_handle, const char *fmt, ...)
va_start(ap, fmt);
vsnprintf(descr, sizeof(descr), fmt, ap);
va_end(ap);
return (intr_describe(isrc->xi_vector, port_handle, descr));
return (intr_describe(isrc->xi_vector, isrc->xi_cookie, descr));
}
void
xen_intr_unbind(xen_intr_handle_t *port_handlep)
{
struct intr_handler *handler;
struct xenisrc *isrc;
handler = *port_handlep;
KASSERT(port_handlep != NULL,
("NULL xen_intr_handle_t passed to xen_intr_unbind"));
isrc = xen_intr_isrc(*port_handlep);
*port_handlep = NULL;
isrc = xen_intr_isrc(handler);
if (isrc == NULL)
return;
intr_remove_handler(handler);
if (isrc->xi_cookie != NULL)
intr_remove_handler(isrc->xi_cookie);
xen_intr_release_isrc(isrc);
}
@ -1492,6 +1509,29 @@ xen_intr_port(xen_intr_handle_t handle)
return (isrc->xi_port);
}
int
xen_intr_add_handler(device_t dev, driver_filter_t filter,
driver_intr_t handler, void *arg, enum intr_type flags,
xen_intr_handle_t handle)
{
struct xenisrc *isrc;
int error;
isrc = xen_intr_isrc(handle);
if (isrc == NULL || isrc->xi_cookie != NULL)
return (EINVAL);
error = intr_add_handler(device_get_nameunit(dev), isrc->xi_vector,
filter, handler, arg, flags|INTR_EXCL, &isrc->xi_cookie);
if (error != 0) {
device_printf(dev,
"xen_intr_add_handler: intr_add_handler failed: %d\n",
error);
}
return (error);
}
#ifdef DDB
static const char *
xen_intr_print_type(enum evtchn_type type)

View File

@ -246,4 +246,23 @@ int xen_register_msi(device_t dev, int vector, int count);
*/
int xen_release_msi(int vector);
/**
* Bind an event channel port with a handler
*
* \param dev The device making this bind request.
* \param filter An interrupt filter handler. Specify NULL
* to always dispatch to the ithread handler.
* \param handler An interrupt ithread handler. Optional (can
* specify NULL) if all necessary event actions
* are performed by filter.
* \param arg Argument to present to both filter and handler.
* \param irqflags Interrupt handler flags. See sys/bus.h.
* \param handle Opaque handle used to manage this registration.
*
* \returns 0 on success, otherwise an errno.
*/
int xen_intr_add_handler(device_t dev, driver_filter_t filter,
driver_intr_t handler, void *arg, enum intr_type flags,
xen_intr_handle_t handle);
#endif /* _XEN_INTR_H_ */