nfs: new subdir Documentation/filesystems/nfs
[safe/jmp/linux-2.6] / drivers / xen / events.c
index 9ce1ab6..2f57276 100644 (file)
 #include <linux/irq.h>
 #include <linux/module.h>
 #include <linux/string.h>
+#include <linux/bootmem.h>
 
 #include <asm/ptrace.h>
 #include <asm/irq.h>
+#include <asm/idle.h>
 #include <asm/sync_bitops.h>
 #include <asm/xen/hypercall.h>
 #include <asm/xen/hypervisor.h>
 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};
 
-/* Packed IRQ information: binding type, sub-type index, and event channel. */
-struct packed_irq
-{
-       unsigned short evtchn;
-       unsigned char index;
-       unsigned char type;
-};
-
-static struct packed_irq irq_info[NR_IRQS];
-
-/* Binding types. */
-enum {
-       IRQT_UNBOUND,
+/* Interrupt types. */
+enum xen_irq_type {
+       IRQT_UNBOUND = 0,
        IRQT_PIRQ,
        IRQT_VIRQ,
        IRQT_IPI,
        IRQT_EVTCHN
 };
 
-/* Convenient shorthand for packed representation of an unbound IRQ. */
-#define IRQ_UNBOUND    mk_irq_info(IRQT_UNBOUND, 0, 0)
+/*
+ * Packed IRQ information:
+ * type - enum xen_irq_type
+ * event channel - irq->event channel mapping
+ * cpu - cpu this event channel is bound to
+ * index - type-specific information:
+ *    PIRQ - vector, with MSB being "needs EIO"
+ *    VIRQ - virq number
+ *    IPI - IPI vector
+ *    EVTCHN -
+ */
+struct irq_info
+{
+       enum xen_irq_type type; /* type */
+       unsigned short evtchn;  /* event channel */
+       unsigned short cpu;     /* cpu bound */
+
+       union {
+               unsigned short virq;
+               enum ipi_vector ipi;
+               struct {
+                       unsigned short gsi;
+                       unsigned short vector;
+               } pirq;
+       } u;
+};
+
+static struct irq_info irq_info[NR_IRQS];
 
 static int evtchn_to_irq[NR_EVENT_CHANNELS] = {
        [0 ... NR_EVENT_CHANNELS-1] = -1
 };
-static unsigned long cpu_evtchn_mask[NR_CPUS][NR_EVENT_CHANNELS/BITS_PER_LONG];
-static u8 cpu_evtchn[NR_EVENT_CHANNELS];
-
-/* Reference counts for bindings to IRQs. */
-static int irq_bindcount[NR_IRQS];
+struct cpu_evtchn_s {
+       unsigned long bits[NR_EVENT_CHANNELS/BITS_PER_LONG];
+};
+static struct cpu_evtchn_s *cpu_evtchn_mask_p;
+static inline unsigned long *cpu_evtchn_mask(int cpu)
+{
+       return cpu_evtchn_mask_p[cpu].bits;
+}
 
 /* Xen will never allocate port zero for any purpose. */
 #define VALID_EVTCHN(chn)      ((chn) != 0)
@@ -87,27 +108,114 @@ static int irq_bindcount[NR_IRQS];
 static struct irq_chip xen_dynamic_chip;
 
 /* Constructor for packed IRQ information. */
-static inline struct packed_irq mk_irq_info(u32 type, u32 index, u32 evtchn)
+static struct irq_info mk_unbound_info(void)
+{
+       return (struct irq_info) { .type = IRQT_UNBOUND };
+}
+
+static struct irq_info mk_evtchn_info(unsigned short evtchn)
+{
+       return (struct irq_info) { .type = IRQT_EVTCHN, .evtchn = evtchn,
+                       .cpu = 0 };
+}
+
+static struct irq_info mk_ipi_info(unsigned short evtchn, enum ipi_vector ipi)
+{
+       return (struct irq_info) { .type = IRQT_IPI, .evtchn = evtchn,
+                       .cpu = 0, .u.ipi = ipi };
+}
+
+static struct irq_info mk_virq_info(unsigned short evtchn, unsigned short virq)
 {
-       return (struct packed_irq) { evtchn, index, type };
+       return (struct irq_info) { .type = IRQT_VIRQ, .evtchn = evtchn,
+                       .cpu = 0, .u.virq = virq };
+}
+
+static struct irq_info mk_pirq_info(unsigned short evtchn,
+                                   unsigned short gsi, unsigned short vector)
+{
+       return (struct irq_info) { .type = IRQT_PIRQ, .evtchn = evtchn,
+                       .cpu = 0, .u.pirq = { .gsi = gsi, .vector = vector } };
 }
 
 /*
  * Accessors for packed IRQ information.
  */
-static inline unsigned int evtchn_from_irq(int irq)
+static struct irq_info *info_for_irq(unsigned irq)
+{
+       return &irq_info[irq];
+}
+
+static unsigned int evtchn_from_irq(unsigned irq)
+{
+       return info_for_irq(irq)->evtchn;
+}
+
+unsigned irq_from_evtchn(unsigned int evtchn)
 {
-       return irq_info[irq].evtchn;
+       return evtchn_to_irq[evtchn];
 }
+EXPORT_SYMBOL_GPL(irq_from_evtchn);
 
-static inline unsigned int index_from_irq(int irq)
+static enum ipi_vector ipi_from_irq(unsigned irq)
 {
-       return irq_info[irq].index;
+       struct irq_info *info = info_for_irq(irq);
+
+       BUG_ON(info == NULL);
+       BUG_ON(info->type != IRQT_IPI);
+
+       return info->u.ipi;
+}
+
+static unsigned virq_from_irq(unsigned irq)
+{
+       struct irq_info *info = info_for_irq(irq);
+
+       BUG_ON(info == NULL);
+       BUG_ON(info->type != IRQT_VIRQ);
+
+       return info->u.virq;
 }
 
-static inline unsigned int type_from_irq(int irq)
+static unsigned gsi_from_irq(unsigned irq)
 {
-       return irq_info[irq].type;
+       struct irq_info *info = info_for_irq(irq);
+
+       BUG_ON(info == NULL);
+       BUG_ON(info->type != IRQT_PIRQ);
+
+       return info->u.pirq.gsi;
+}
+
+static unsigned vector_from_irq(unsigned irq)
+{
+       struct irq_info *info = info_for_irq(irq);
+
+       BUG_ON(info == NULL);
+       BUG_ON(info->type != IRQT_PIRQ);
+
+       return info->u.pirq.vector;
+}
+
+static enum xen_irq_type type_from_irq(unsigned irq)
+{
+       return info_for_irq(irq)->type;
+}
+
+static unsigned cpu_from_irq(unsigned irq)
+{
+       return info_for_irq(irq)->cpu;
+}
+
+static unsigned int cpu_from_evtchn(unsigned int evtchn)
+{
+       int irq = evtchn_to_irq[evtchn];
+       unsigned ret = 0;
+
+       if (irq != -1)
+               ret = cpu_from_irq(irq);
+
+       return ret;
 }
 
 static inline unsigned long active_evtchns(unsigned int cpu,
@@ -115,7 +223,7 @@ static inline unsigned long active_evtchns(unsigned int cpu,
                                           unsigned int idx)
 {
        return (sh->evtchn_pending[idx] &
-               cpu_evtchn_mask[cpu][idx] &
+               cpu_evtchn_mask(cpu)[idx] &
                ~sh->evtchn_mask[idx]);
 }
 
@@ -125,13 +233,13 @@ static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
 
        BUG_ON(irq == -1);
 #ifdef CONFIG_SMP
-       irq_to_desc(irq)->affinity = cpumask_of_cpu(cpu);
+       cpumask_copy(irq_to_desc(irq)->affinity, cpumask_of(cpu));
 #endif
 
-       __clear_bit(chn, cpu_evtchn_mask[cpu_evtchn[chn]]);
-       __set_bit(chn, cpu_evtchn_mask[cpu]);
+       __clear_bit(chn, cpu_evtchn_mask(cpu_from_irq(irq)));
+       __set_bit(chn, cpu_evtchn_mask(cpu));
 
-       cpu_evtchn[chn] = cpu;
+       irq_info[irq].cpu = cpu;
 }
 
 static void init_evtchn_cpu_bindings(void)
@@ -141,17 +249,12 @@ static void init_evtchn_cpu_bindings(void)
        int i;
 
        /* By default all event channels notify CPU#0. */
-       for_each_irq_desc(i, desc)
-               desc->affinity = cpumask_of_cpu(0);
+       for_each_irq_desc(i, desc) {
+               cpumask_copy(desc->affinity, cpumask_of(0));
+       }
 #endif
 
-       memset(cpu_evtchn, 0, sizeof(cpu_evtchn));
-       memset(cpu_evtchn_mask[0], ~0, sizeof(cpu_evtchn_mask[0]));
-}
-
-static inline unsigned int cpu_from_evtchn(unsigned int evtchn)
-{
-       return cpu_evtchn[evtchn];
+       memset(cpu_evtchn_mask(0), ~0, sizeof(cpu_evtchn_mask(0)));
 }
 
 static inline void clear_evtchn(int port)
@@ -229,15 +332,21 @@ static void unmask_evtchn(int port)
 static int find_unbound_irq(void)
 {
        int irq;
+       struct irq_desc *desc;
 
-       /* Only allocate from dynirq range */
-       for_each_irq_nr(irq)
-               if (irq_bindcount[irq] == 0)
+       for (irq = 0; irq < nr_irqs; irq++)
+               if (irq_info[irq].type == IRQT_UNBOUND)
                        break;
 
        if (irq == nr_irqs)
                panic("No available IRQ to bind to: increase nr_irqs!\n");
 
+       desc = irq_to_desc_alloc_node(irq, 0);
+       if (WARN_ON(desc == NULL))
+               return -1;
+
+       dynamic_irq_init(irq);
+
        return irq;
 }
 
@@ -252,16 +361,13 @@ int bind_evtchn_to_irq(unsigned int evtchn)
        if (irq == -1) {
                irq = find_unbound_irq();
 
-               dynamic_irq_init(irq);
                set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
                                              handle_level_irq, "event");
 
                evtchn_to_irq[evtchn] = irq;
-               irq_info[irq] = mk_irq_info(IRQT_EVTCHN, 0, evtchn);
+               irq_info[irq] = mk_evtchn_info(evtchn);
        }
 
-       irq_bindcount[irq]++;
-
        spin_unlock(&irq_mapping_update_lock);
 
        return irq;
@@ -276,12 +382,12 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
        spin_lock(&irq_mapping_update_lock);
 
        irq = per_cpu(ipi_to_irq, cpu)[ipi];
+
        if (irq == -1) {
                irq = find_unbound_irq();
                if (irq < 0)
                        goto out;
 
-               dynamic_irq_init(irq);
                set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
                                              handle_level_irq, "ipi");
 
@@ -292,15 +398,12 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
                evtchn = bind_ipi.port;
 
                evtchn_to_irq[evtchn] = irq;
-               irq_info[irq] = mk_irq_info(IRQT_IPI, ipi, evtchn);
-
+               irq_info[irq] = mk_ipi_info(evtchn, ipi);
                per_cpu(ipi_to_irq, cpu)[ipi] = irq;
 
                bind_evtchn_to_cpu(evtchn, cpu);
        }
 
-       irq_bindcount[irq]++;
-
  out:
        spin_unlock(&irq_mapping_update_lock);
        return irq;
@@ -326,20 +429,17 @@ static int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
 
                irq = find_unbound_irq();
 
-               dynamic_irq_init(irq);
                set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
                                              handle_level_irq, "virq");
 
                evtchn_to_irq[evtchn] = irq;
-               irq_info[irq] = mk_irq_info(IRQT_VIRQ, virq, evtchn);
+               irq_info[irq] = mk_virq_info(evtchn, virq);
 
                per_cpu(virq_to_irq, cpu)[virq] = irq;
 
                bind_evtchn_to_cpu(evtchn, cpu);
        }
 
-       irq_bindcount[irq]++;
-
        spin_unlock(&irq_mapping_update_lock);
 
        return irq;
@@ -352,7 +452,7 @@ static void unbind_from_irq(unsigned int irq)
 
        spin_lock(&irq_mapping_update_lock);
 
-       if ((--irq_bindcount[irq] == 0) && VALID_EVTCHN(evtchn)) {
+       if (VALID_EVTCHN(evtchn)) {
                close.port = evtchn;
                if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
                        BUG();
@@ -360,11 +460,11 @@ static void unbind_from_irq(unsigned int irq)
                switch (type_from_irq(irq)) {
                case IRQT_VIRQ:
                        per_cpu(virq_to_irq, cpu_from_evtchn(evtchn))
-                               [index_from_irq(irq)] = -1;
+                               [virq_from_irq(irq)] = -1;
                        break;
                case IRQT_IPI:
                        per_cpu(ipi_to_irq, cpu_from_evtchn(evtchn))
-                               [index_from_irq(irq)] = -1;
+                               [ipi_from_irq(irq)] = -1;
                        break;
                default:
                        break;
@@ -374,7 +474,7 @@ static void unbind_from_irq(unsigned int irq)
                bind_evtchn_to_cpu(evtchn, 0);
 
                evtchn_to_irq[evtchn] = -1;
-               irq_info[irq] = IRQ_UNBOUND;
+               irq_info[irq] = mk_unbound_info();
 
                dynamic_irq_cleanup(irq);
        }
@@ -492,8 +592,8 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
        for(i = 0; i < NR_EVENT_CHANNELS; i++) {
                if (sync_test_bit(i, sh->evtchn_pending)) {
                        printk("  %d: event %d -> irq %d\n",
-                               cpu_evtchn[i], i,
-                               evtchn_to_irq[i]);
+                              cpu_from_evtchn(i), i,
+                              evtchn_to_irq[i]);
                }
        }
 
@@ -502,6 +602,7 @@ 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
@@ -515,17 +616,20 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
 void xen_evtchn_do_upcall(struct pt_regs *regs)
 {
        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. */
@@ -544,23 +648,28 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
                                int irq = evtchn_to_irq[port];
 
                                if (irq != -1)
-                                       xen_do_IRQ(irq, regs);
+                                       handle_irq(irq, regs);
                        }
                }
 
                BUG_ON(!irqs_disabled());
 
-               count = __get_cpu_var(nesting_count);
-               __get_cpu_var(nesting_count) = 0;
+               count = __get_cpu_var(xed_nesting_count);
+               __get_cpu_var(xed_nesting_count) = 0;
        } while(count != 1);
 
 out:
+       irq_exit();
+       set_irq_regs(old_regs);
+
        put_cpu();
 }
 
 /* Rebind a new event channel to an existing irq. */
 void rebind_evtchn_irq(int evtchn, int irq)
 {
+       struct irq_info *info = info_for_irq(irq);
+
        /* Make sure the irq is masked, since the new event channel
           will also be masked. */
        disable_irq(irq);
@@ -570,29 +679,29 @@ void rebind_evtchn_irq(int evtchn, int irq)
        /* After resume the irq<->evtchn mappings are all cleared out */
        BUG_ON(evtchn_to_irq[evtchn] != -1);
        /* Expect irq to have been bound before,
-          so the bindcount should be non-0 */
-       BUG_ON(irq_bindcount[irq] == 0);
+          so there should be a proper type */
+       BUG_ON(info->type == IRQT_UNBOUND);
 
        evtchn_to_irq[evtchn] = irq;
-       irq_info[irq] = mk_irq_info(IRQT_EVTCHN, 0, evtchn);
+       irq_info[irq] = mk_evtchn_info(evtchn);
 
        spin_unlock(&irq_mapping_update_lock);
 
        /* new event channels are always bound to cpu 0 */
-       irq_set_affinity(irq, cpumask_of_cpu(0));
+       irq_set_affinity(irq, cpumask_of(0));
 
        /* Unmask the event channel. */
        enable_irq(irq);
 }
 
 /* Rebind an evtchn so that it gets delivered to a specific cpu */
-static void rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
+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))
-               return;
+               return -1;
 
        /* Send future instances of this interrupt to other vcpu. */
        bind_vcpu.port = evtchn;
@@ -605,13 +714,15 @@ static void rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
         */
        if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
                bind_evtchn_to_cpu(evtchn, tcpu);
-}
 
+       return 0;
+}
 
-static void set_affinity_irq(unsigned irq, cpumask_t dest)
+static int set_affinity_irq(unsigned irq, const struct cpumask *dest)
 {
-       unsigned tcpu = first_cpu(dest);
-       rebind_irq_to_cpu(irq, tcpu);
+       unsigned tcpu = cpumask_first(dest);
+
+       return rebind_irq_to_cpu(irq, tcpu);
 }
 
 int resend_irq_on_evtchn(unsigned int irq)
@@ -684,8 +795,7 @@ static void restore_cpu_virqs(unsigned int cpu)
                if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
                        continue;
 
-               BUG_ON(irq_info[irq].type != IRQT_VIRQ);
-               BUG_ON(irq_info[irq].index != virq);
+               BUG_ON(virq_from_irq(irq) != virq);
 
                /* Get a new binding from Xen. */
                bind_virq.virq = virq;
@@ -697,7 +807,7 @@ static void restore_cpu_virqs(unsigned int cpu)
 
                /* Record the new mapping. */
                evtchn_to_irq[evtchn] = irq;
-               irq_info[irq] = mk_irq_info(IRQT_VIRQ, virq, evtchn);
+               irq_info[irq] = mk_virq_info(evtchn, virq);
                bind_evtchn_to_cpu(evtchn, cpu);
 
                /* Ready for use. */
@@ -714,8 +824,7 @@ static void restore_cpu_ipis(unsigned int cpu)
                if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
                        continue;
 
-               BUG_ON(irq_info[irq].type != IRQT_IPI);
-               BUG_ON(irq_info[irq].index != ipi);
+               BUG_ON(ipi_from_irq(irq) != ipi);
 
                /* Get a new binding from Xen. */
                bind_ipi.vcpu = cpu;
@@ -726,7 +835,7 @@ static void restore_cpu_ipis(unsigned int cpu)
 
                /* Record the new mapping. */
                evtchn_to_irq[evtchn] = irq;
-               irq_info[irq] = mk_irq_info(IRQT_IPI, ipi, evtchn);
+               irq_info[irq] = mk_ipi_info(evtchn, ipi);
                bind_evtchn_to_cpu(evtchn, cpu);
 
                /* Ready for use. */
@@ -774,7 +883,7 @@ void xen_poll_irq(int irq)
 
                poll.nr_ports = 1;
                poll.timeout = 0;
-               poll.ports = &evtchn;
+               set_xen_guest_handle(poll.ports, &evtchn);
 
                if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
                        BUG();
@@ -792,7 +901,7 @@ void xen_irq_resume(void)
                mask_evtchn(evtchn);
 
        /* No IRQ <-> event-channel mappings. */
-       for_each_irq_nr(irq)
+       for (irq = 0; irq < nr_irqs; irq++)
                irq_info[irq].evtchn = 0; /* zap event-channel binding */
 
        for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
@@ -806,8 +915,11 @@ void xen_irq_resume(void)
 
 static struct irq_chip xen_dynamic_chip __read_mostly = {
        .name           = "xen-dyn",
+
+       .disable        = disable_dynirq,
        .mask           = disable_dynirq,
        .unmask         = enable_dynirq,
+
        .ack            = ack_dynirq,
        .set_affinity   = set_affinity_irq,
        .retrigger      = retrigger_dynirq,
@@ -817,15 +929,15 @@ void __init xen_init_IRQ(void)
 {
        int i;
 
+       cpu_evtchn_mask_p = kcalloc(nr_cpu_ids, sizeof(struct cpu_evtchn_s),
+                                   GFP_KERNEL);
+       BUG_ON(cpu_evtchn_mask_p == NULL);
+
        init_evtchn_cpu_bindings();
 
        /* No event channels are 'live' right now. */
        for (i = 0; i < NR_EVENT_CHANNELS; i++)
                mask_evtchn(i);
 
-       /* Dynamic IRQ space is currently unbound. Zero the refcnts. */
-       for_each_irq_nr(i)
-               irq_bindcount[i] = 0;
-
        irq_ctx_init(smp_processor_id());
 }