aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/xen/events.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/xen/events.c')
-rw-r--r--drivers/xen/events.c120
1 files changed, 101 insertions, 19 deletions
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index abad71b..5e1f348 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -27,7 +27,9 @@
#include <linux/module.h>
#include <linux/string.h>
#include <linux/bootmem.h>
+#include <linux/slab.h>
+#include <asm/desc.h>
#include <asm/ptrace.h>
#include <asm/irq.h>
#include <asm/idle.h>
@@ -35,10 +37,14 @@
#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>
+#include <xen/xen.h>
+#include <xen/hvm.h>
#include <xen/xen-ops.h>
#include <xen/events.h>
#include <xen/interface/xen.h>
#include <xen/interface/event_channel.h>
+#include <xen/interface/hvm/hvm_op.h>
+#include <xen/interface/hvm/params.h>
/*
* This lock protects updates to the following mapping and reference-count
@@ -47,10 +53,10 @@
static DEFINE_SPINLOCK(irq_mapping_update_lock);
/* IRQ <-> VIRQ mapping. */
-static DEFINE_PER_CPU(int, virq_to_irq[NR_VIRQS]) = {[0 ... NR_VIRQS-1] = -1};
+static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
/* IRQ <-> IPI mapping */
-static DEFINE_PER_CPU(int, ipi_to_irq[XEN_NR_IPIS]) = {[0 ... XEN_NR_IPIS-1] = -1};
+static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1] = -1};
/* Interrupt types. */
enum xen_irq_type {
@@ -334,9 +340,18 @@ static int find_unbound_irq(void)
int irq;
struct irq_desc *desc;
- for (irq = 0; irq < nr_irqs; irq++)
+ for (irq = 0; irq < nr_irqs; irq++) {
+ desc = irq_to_desc(irq);
+ /* only 0->15 have init'd desc; handle irq > 16 */
+ if (desc == NULL)
+ break;
+ if (desc->chip == &no_irq_chip)
+ break;
+ if (desc->chip != &xen_dynamic_chip)
+ continue;
if (irq_info[irq].type == IRQT_UNBOUND)
break;
+ }
if (irq == nr_irqs)
panic("No available IRQ to bind to: increase nr_irqs!\n");
@@ -345,7 +360,7 @@ static int find_unbound_irq(void)
if (WARN_ON(desc == NULL))
return -1;
- dynamic_irq_init(irq);
+ dynamic_irq_init_keep_chip_data(irq);
return irq;
}
@@ -474,6 +489,9 @@ static void unbind_from_irq(unsigned int irq)
bind_evtchn_to_cpu(evtchn, 0);
evtchn_to_irq[evtchn] = -1;
+ }
+
+ if (irq_info[irq].type != IRQT_UNBOUND) {
irq_info[irq] = mk_unbound_info();
dynamic_irq_cleanup(irq);
@@ -602,6 +620,8 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}
+static DEFINE_PER_CPU(unsigned, xed_nesting_count);
+
/*
* Search the CPUs pending events bitmasks. For each one found, map
* the event number to an irq, and feed it into do_IRQ() for
@@ -611,24 +631,19 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
* a bitset of words which contain pending event bits. The second
* level is a bitset of pending events themselves.
*/
-void xen_evtchn_do_upcall(struct pt_regs *regs)
+static void __xen_evtchn_do_upcall(void)
{
int cpu = get_cpu();
- struct pt_regs *old_regs = set_irq_regs(regs);
struct shared_info *s = HYPERVISOR_shared_info;
struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
- static DEFINE_PER_CPU(unsigned, nesting_count);
unsigned count;
- exit_idle();
- irq_enter();
-
do {
unsigned long pending_words;
vcpu_info->evtchn_upcall_pending = 0;
- if (__get_cpu_var(nesting_count)++)
+ if (__get_cpu_var(xed_nesting_count)++)
goto out;
#ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */
@@ -645,24 +660,45 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
int bit_idx = __ffs(pending_bits);
int port = (word_idx * BITS_PER_LONG) + bit_idx;
int irq = evtchn_to_irq[port];
+ struct irq_desc *desc;
- if (irq != -1)
- handle_irq(irq, regs);
+ if (irq != -1) {
+ desc = irq_to_desc(irq);
+ if (desc)
+ generic_handle_irq_desc(irq, desc);
+ }
}
}
BUG_ON(!irqs_disabled());
- count = __get_cpu_var(nesting_count);
- __get_cpu_var(nesting_count) = 0;
- } while(count != 1);
+ count = __get_cpu_var(xed_nesting_count);
+ __get_cpu_var(xed_nesting_count) = 0;
+ } while (count != 1 || vcpu_info->evtchn_upcall_pending);
out:
+
+ put_cpu();
+}
+
+void xen_evtchn_do_upcall(struct pt_regs *regs)
+{
+ struct pt_regs *old_regs = set_irq_regs(regs);
+
+ exit_idle();
+ irq_enter();
+
+ __xen_evtchn_do_upcall();
+
irq_exit();
set_irq_regs(old_regs);
+}
- put_cpu();
+void xen_hvm_evtchn_do_upcall(void)
+{
+ __xen_evtchn_do_upcall();
}
+EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
/* Rebind a new event channel to an existing irq. */
void rebind_evtchn_irq(int evtchn, int irq)
@@ -699,7 +735,10 @@ static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
struct evtchn_bind_vcpu bind_vcpu;
int evtchn = evtchn_from_irq(irq);
- if (!VALID_EVTCHN(evtchn))
+ /* events delivered via platform PCI interrupts are always
+ * routed to vcpu 0 */
+ if (!VALID_EVTCHN(evtchn) ||
+ (xen_hvm_domain() && !xen_have_vector_callback))
return -1;
/* Send future instances of this interrupt to other vcpu. */
@@ -924,6 +963,44 @@ static struct irq_chip xen_dynamic_chip __read_mostly = {
.retrigger = retrigger_dynirq,
};
+int xen_set_callback_via(uint64_t via)
+{
+ struct xen_hvm_param a;
+ a.domid = DOMID_SELF;
+ a.index = HVM_PARAM_CALLBACK_IRQ;
+ a.value = via;
+ return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
+}
+EXPORT_SYMBOL_GPL(xen_set_callback_via);
+
+#ifdef CONFIG_XEN_PVHVM
+/* Vector callbacks are better than PCI interrupts to receive event
+ * channel notifications because we can receive vector callbacks on any
+ * vcpu and we don't need PCI support or APIC interactions. */
+void xen_callback_vector(void)
+{
+ int rc;
+ uint64_t callback_via;
+ if (xen_have_vector_callback) {
+ callback_via = HVM_CALLBACK_VECTOR(XEN_HVM_EVTCHN_CALLBACK);
+ rc = xen_set_callback_via(callback_via);
+ if (rc) {
+ printk(KERN_ERR "Request for Xen HVM callback vector"
+ " failed.\n");
+ xen_have_vector_callback = 0;
+ return;
+ }
+ printk(KERN_INFO "Xen HVM callback vector for event delivery is "
+ "enabled\n");
+ /* in the restore case the vector has already been allocated */
+ if (!test_bit(XEN_HVM_EVTCHN_CALLBACK, used_vectors))
+ alloc_intr_gate(XEN_HVM_EVTCHN_CALLBACK, xen_hvm_callback_vector);
+ }
+}
+#else
+void xen_callback_vector(void) {}
+#endif
+
void __init xen_init_IRQ(void)
{
int i;
@@ -938,5 +1015,10 @@ void __init xen_init_IRQ(void)
for (i = 0; i < NR_EVENT_CHANNELS; i++)
mask_evtchn(i);
- irq_ctx_init(smp_processor_id());
+ if (xen_hvm_domain()) {
+ xen_callback_vector();
+ native_init_IRQ();
+ } else {
+ irq_ctx_init(smp_processor_id());
+ }
}
generated by cgit v1.1 at 2025-02-28 08:41:28 +0000