Page MenuHomeFreeBSD
Differential D30936 Diff 95054 sys/x86/xen/xen_arch_intr.c

Changeset View

Standalone View

View Options

sys/x86/xen/xen_arch_intr.c

Show First 20 Lines • Show All 42 Lines • ▼ Show 20 Lines
#include <machine/intr_machdep.h> #include <machine/intr_machdep.h>
#include <x86/apicvar.h> #include <x86/apicvar.h>
#include <xen/xen-os.h> #include <xen/xen-os.h>
#include <xen/xen_intr.h> #include <xen/xen_intr.h>
#include <xen/arch-intr.h> #include <xen/arch-intr.h>
/*
* Lock for x86-related structures. Notably modifying
* xen_intr_auto_vector_count, and allocating interrupts require this lock be
* held.
*/
static struct mtx xen_intr_x86_lock;
static u_int first_evtchn_irq;
static u_int xen_intr_auto_vector_count;
void
xen_intr_alloc_irqs(void)
{
if (num_io_irqs > UINT_MAX - NR_EVENT_CHANNELS)
panic("IRQ allocation overflow (num_msi_irqs too high?)");
first_evtchn_irq = num_io_irqs;
num_io_irqs += NR_EVENT_CHANNELS;
}
/********************************* EVTCHN PIC ********************************/ /********************************* EVTCHN PIC ********************************/
static void static void
xen_intr_pic_enable_source(struct intsrc *isrc) xen_intr_pic_enable_source(struct intsrc *isrc)
{ {
CTASSERT(offsetof(struct xenisrc, xi_arch.xai_intsrc) == 0); CTASSERT(offsetof(struct xenisrc, xi_arch.xai_intsrc) == 0);
▲ Show 20 Lines • Show All 111 Lines • ▼ Show 20 Linesxen_intr_pic_assign_cpu(struct intsrc *isrc, u_int apic_id)
return (xen_intr_assign_cpu((struct xenisrc *)isrc, return (xen_intr_assign_cpu((struct xenisrc *)isrc,
apic_cpuid(apic_id))); apic_cpuid(apic_id)));
} }
/** /**
* PIC interface for all event channel port types except physical IRQs. * PIC interface for all event channel port types except physical IRQs.
*/ */
struct pic xen_intr_pic = { static struct pic xen_intr_pic = {
.pic_enable_source = xen_intr_pic_enable_source, .pic_enable_source = xen_intr_pic_enable_source,
.pic_disable_source = xen_intr_pic_disable_source, .pic_disable_source = xen_intr_pic_disable_source,
.pic_eoi_source = xen_intr_pic_eoi_source, .pic_eoi_source = xen_intr_pic_eoi_source,
.pic_enable_intr = xen_intr_pic_enable_intr, .pic_enable_intr = xen_intr_pic_enable_intr,
.pic_disable_intr = xen_intr_pic_disable_intr, .pic_disable_intr = xen_intr_pic_disable_intr,
.pic_vector = xen_intr_pic_vector, .pic_vector = xen_intr_pic_vector,
.pic_source_pending = xen_intr_pic_source_pending, .pic_source_pending = xen_intr_pic_source_pending,
.pic_suspend = xen_intr_pic_suspend, .pic_suspend = xen_intr_pic_suspend,
.pic_resume = xen_intr_pic_resume, .pic_resume = xen_intr_pic_resume,
.pic_config_intr = xen_intr_pic_config_intr, .pic_config_intr = xen_intr_pic_config_intr,
.pic_assign_cpu = xen_intr_pic_assign_cpu .pic_assign_cpu = xen_intr_pic_assign_cpu
}; };
/****************************** ARCH wrappers ********************************/ /****************************** ARCH wrappers ********************************/
void void
xen_arch_intr_init(void) xen_arch_intr_init(void)
{ {
mtx_init(&xen_intr_x86_lock, "xen-x86-table-lock", NULL, MTX_DEF);
intr_register_pic(&xen_intr_pic); intr_register_pic(&xen_intr_pic);
}
/**
* Search for an already allocated but currently unused Xen interrupt
* source object.
*
* \param type Restrict the search to interrupt sources of the given
* type.
*
* \return A pointer to a free Xen interrupt source object or NULL.
*/
static struct xenisrc *
xen_intr_find_unused_isrc(enum evtchn_type type)
{
int isrc_idx;
mtx_assert(&xen_intr_x86_lock, MA_OWNED);
for (isrc_idx = 0; isrc_idx < xen_intr_auto_vector_count; isrc_idx ++) {
struct xenisrc *isrc;
u_int vector;
vector = first_evtchn_irq + isrc_idx;
isrc = (struct xenisrc *)intr_lookup_source(vector);
if (isrc != NULL
&& isrc->xi_type == EVTCHN_TYPE_UNBOUND) {
KASSERT(xen_arch_intr_has_handlers(isrc),
("Free evtchn still has handlers"));
isrc->xi_type = type;
return (isrc);
}
}
return (NULL);
}
/**
* Allocate a Xen interrupt source object.
*
* \param type The type of interrupt source to create.
*
* \return A pointer to a newly allocated Xen interrupt source
* object or NULL.
*/
struct xenisrc *
xen_arch_intr_alloc(struct malloc_type *mtype, const char *name __unused,
enum evtchn_type type, evtchn_port_t port)
{
static int warned;
struct xenisrc *isrc;
unsigned int vector;
mtx_lock(&xen_intr_x86_lock);
isrc = xen_intr_find_unused_isrc(type);
if (isrc != NULL) {
mtx_unlock(&xen_intr_x86_lock);
goto out;
}
if (xen_intr_auto_vector_count >= NR_EVENT_CHANNELS) {
if (!warned) {
warned = 1;
printf("%s: Xen interrupts exhausted.\n", __func__);
}
mtx_unlock(&xen_intr_x86_lock);
return (NULL);
}
vector = first_evtchn_irq + xen_intr_auto_vector_count;
xen_intr_auto_vector_count++;
mtx_unlock(&xen_intr_x86_lock);
isrc = malloc(sizeof(*isrc), mtype, M_WAITOK | M_ZERO);
isrc->xi_arch.xai_intsrc.is_pic = &xen_intr_pic;
isrc->xi_arch.xai_vector = vector;
isrc->xi_type = type;
if (intr_register_source(&isrc->xi_arch.xai_intsrc) != 0) {
free(isrc, mtype);
return (NULL);
}
out:
/* xen_intr_assign_cpu() requires this to be set */
isrc->xi_port = port;
#ifdef SMP
if (type == EVTCHN_TYPE_PORT) {
/*
* By default all interrupts are assigned to vCPU#0
* unless specified otherwise, so shuffle them to balance
* the interrupt load.
*/
xen_intr_assign_cpu(isrc, intr_next_cpu(0));
}
#endif
return (isrc);
}
void
xen_arch_intr_release(struct malloc_type *mtype __unused, struct xenisrc *isrc)
{
isrc->xi_cpu = 0;
isrc->xi_port = ~0;
isrc->xi_cookie = NULL;
/*
* Fun with locking here. xen_intr_x86_lock is actually controlling
* *allocation*. This means the isrc isn't under control of the lock
ehem_freebsd_m5p.comAuthorUnsubmitted
Done
Inline Actions

Mentioned on D30726, should this segment be dropped? These values must be set during the allocation process, while the architecture code only looks at ->xi_type (== EVTCHN_TYPE_UNBOUND, presently unallocated, other values indicate in use). Though looks like xen_intr_bind_isrc() may need to start clearing ->xi_cookie (which it should have been doing already, D31188 implements this implicitly).

ehem_freebsd_m5p.com: Mentioned on D30726, should this segment be dropped? These values //must// be set during the…
* until ->xi_type == EVTCHN_TYPE_UNBOUND. The consequence is
* atomic_store_rel() is appropriate since we merely need the other
* stores to complete before this one. This one simply needs to
* complete atomically.
*/
atomic_store_rel_32(&isrc->xi_type, EVTCHN_TYPE_UNBOUND);
} }
bool bool
xen_arch_intr_has_handlers(struct xenisrc *isrc) xen_arch_intr_has_handlers(struct xenisrc *isrc)
{ {
return (isrc->xi_arch.xai_intsrc.is_handlers != 0); return (isrc->xi_arch.xai_intsrc.is_handlers != 0);
} }
Show All 39 Lines