xen: pack all irq-related info together

Put all irq info into one struct.  Also, use a union to keep
event channel type-specific information, rather than overloading the
index field.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 135 insertions, 49 deletions

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 2c8d710713f5..0541e07d4f67 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -52,18 +52,8 @@ static DEFINE_PER_CPU(int, virq_to_irq[NR_VIRQS]) = {[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};
 
-/* 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 {
+/* Interrupt types. */
+enum xen_irq_type {
         IRQT_UNBOUND,
         IRQT_PIRQ,
         IRQT_VIRQ,
@@ -71,8 +61,34 @@ enum {
         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
@@ -85,7 +101,6 @@ static inline unsigned long *cpu_evtchn_mask(int cpu)
 {
         return cpu_evtchn_mask_p[cpu].bits;
 }
-static u8 cpu_evtchn[NR_EVENT_CHANNELS];
 
 /* Reference counts for bindings to IRQs. */
 static int irq_bindcount[NR_IRQS];
@@ -96,27 +111,107 @@ 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 };
+}
+
+static struct irq_info mk_ipi_info(unsigned short evtchn, enum ipi_vector ipi)
 {
-        return (struct packed_irq) { evtchn, index, type };
+        return (struct irq_info) { .type = IRQT_IPI, .evtchn = evtchn,
+                        .u.ipi = ipi };
+}
+
+static struct irq_info mk_virq_info(unsigned short evtchn, unsigned short virq)
+{
+        return (struct irq_info) { .type = IRQT_VIRQ, .evtchn = evtchn,
+                        .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,
+                        .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].evtchn;
+        return &irq_info[irq];
 }
 
-static inline unsigned int index_from_irq(int irq)
+static unsigned int evtchn_from_irq(unsigned irq)
 {
-        return irq_info[irq].index;
+        return info_for_irq(irq)->evtchn;
 }
 
-static inline unsigned int type_from_irq(int irq)
+static enum ipi_vector ipi_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_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 unsigned gsi_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.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,
@@ -137,10 +232,10 @@ static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
         cpumask_copy(irq_to_desc(irq)->affinity, cpumask_of(cpu));
 #endif
 
-        __clear_bit(chn, cpu_evtchn_mask(cpu_evtchn[chn]));
+        __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)
@@ -155,15 +250,9 @@ static void init_evtchn_cpu_bindings(void)
         }
 #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];
-}
-
 static inline void clear_evtchn(int port)
 {
         struct shared_info *s = HYPERVISOR_shared_info;
@@ -253,6 +342,8 @@ static int find_unbound_irq(void)
         if (WARN_ON(desc == NULL))
                 return -1;
 
+        dynamic_irq_init(irq);
+
         return irq;
 }
 
@@ -267,12 +358,11 @@ 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]++;
@@ -296,7 +386,6 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
                 if (irq < 0)
                         goto out;
 
-                dynamic_irq_init(irq);
                 set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
                                               handle_level_irq, "ipi");
 
@@ -307,7 +396,7 @@ 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;
 
@@ -341,12 +430,11 @@ 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;
 
@@ -375,11 +463,11 @@ 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;
@@ -389,7 +477,7 @@ 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);
         }
@@ -507,8 +595,8 @@ 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]);
                 }
         }
 
@@ -606,7 +694,7 @@ void rebind_evtchn_irq(int evtchn, int irq)
         BUG_ON(irq_bindcount[irq] == 0);
 
         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);
 
@@ -716,8 +804,7 @@ 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;
@@ -729,7 +816,7 @@ 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. */
@@ -746,8 +833,7 @@ 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;
@@ -758,7 +844,7 @@ 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. */