[IA64] Add mapping table between irq and vector

Add mapping tables between irqs and vectors, and its management code.
This is necessary for supporting multiple vector domain because 1:1
mapping between irq and vector will be changed to n:1.

The irq == vector relationship between irqs and vectors is explicitly
remained for percpu interrupts, platform interrupts, isa IRQs and
vectors assigned using assign_irq_vector() because some programs might
depend on it.

And I should consider the following problem.

When pci drivers enabled/disabled devices dynamically, its irq number
is changed to the different one. Therefore, suspend/resume code may
happen problem.

To fix this problem, I bound gsi to irq.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 166 insertions, 35 deletions

diff --git a/arch/ia64/kernel/irq_ia64.c b/arch/ia64/kernel/irq_ia64.c
index bc47049f060f..072427c2c3f6 100644
--- a/arch/ia64/kernel/irq_ia64.c
+++ b/arch/ia64/kernel/irq_ia64.c
@@ -46,6 +46,12 @@
 
 #define IRQ_DEBUG       0
 
+#define IRQ_VECTOR_UNASSIGNED   (0)
+
+#define IRQ_UNUSED              (0)
+#define IRQ_USED                (1)
+#define IRQ_RSVD                (2)
+
 /* These can be overridden in platform_irq_init */
 int ia64_first_device_vector = IA64_DEF_FIRST_DEVICE_VECTOR;
 int ia64_last_device_vector = IA64_DEF_LAST_DEVICE_VECTOR;
@@ -64,46 +70,161 @@ __u8 isa_irq_to_vector_map[16] = {
 };
 EXPORT_SYMBOL(isa_irq_to_vector_map);
 
-static unsigned long ia64_vector_mask[BITS_TO_LONGS(IA64_MAX_DEVICE_VECTORS)];
+DEFINE_SPINLOCK(vector_lock);
+
+struct irq_cfg irq_cfg[NR_IRQS] __read_mostly = {
+        [0 ... NR_IRQS - 1] = { .vector = IRQ_VECTOR_UNASSIGNED }
+};
+
+DEFINE_PER_CPU(int[IA64_NUM_VECTORS], vector_irq) = {
+        [0 ... IA64_NUM_VECTORS - 1] = IA64_SPURIOUS_INT_VECTOR
+};
+
+static int irq_status[NR_IRQS] = {
+        [0 ... NR_IRQS -1] = IRQ_UNUSED
+};
+
+int check_irq_used(int irq)
+{
+        if (irq_status[irq] == IRQ_USED)
+                return 1;
+
+        return -1;
+}
+
+static void reserve_irq(unsigned int irq)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&vector_lock, flags);
+        irq_status[irq] = IRQ_RSVD;
+        spin_unlock_irqrestore(&vector_lock, flags);
+}
+
+static inline int find_unassigned_irq(void)
+{
+        int irq;
+
+        for (irq = IA64_FIRST_DEVICE_VECTOR; irq < NR_IRQS; irq++)
+                if (irq_status[irq] == IRQ_UNUSED)
+                        return irq;
+        return -ENOSPC;
+}
+
+static inline int find_unassigned_vector(void)
+{
+        int vector;
+
+        for (vector = IA64_FIRST_DEVICE_VECTOR;
+             vector <= IA64_LAST_DEVICE_VECTOR; vector++)
+                if (__get_cpu_var(vector_irq[vector]) == IA64_SPURIOUS_INT_VECTOR)
+                        return vector;
+        return -ENOSPC;
+}
+
+static int __bind_irq_vector(int irq, int vector)
+{
+        int cpu;
+
+        if (irq_to_vector(irq) == vector)
+                return 0;
+        if (irq_to_vector(irq) != IRQ_VECTOR_UNASSIGNED)
+                return -EBUSY;
+        for_each_online_cpu(cpu)
+                per_cpu(vector_irq, cpu)[vector] = irq;
+        irq_cfg[irq].vector = vector;
+        irq_status[irq] = IRQ_USED;
+        return 0;
+}
+
+int bind_irq_vector(int irq, int vector)
+{
+        unsigned long flags;
+        int ret;
+
+        spin_lock_irqsave(&vector_lock, flags);
+        ret = __bind_irq_vector(irq, vector);
+        spin_unlock_irqrestore(&vector_lock, flags);
+        return ret;
+}
+
+static void clear_irq_vector(int irq)
+{
+        unsigned long flags;
+        int vector, cpu;
+
+        spin_lock_irqsave(&vector_lock, flags);
+        BUG_ON((unsigned)irq >= NR_IRQS);
+        BUG_ON(irq_cfg[irq].vector == IRQ_VECTOR_UNASSIGNED);
+        vector = irq_cfg[irq].vector;
+        for_each_online_cpu(cpu)
+                per_cpu(vector_irq, cpu)[vector] = IA64_SPURIOUS_INT_VECTOR;
+        irq_cfg[irq].vector = IRQ_VECTOR_UNASSIGNED;
+        irq_status[irq] = IRQ_UNUSED;
+        spin_unlock_irqrestore(&vector_lock, flags);
+}
 
 int
 assign_irq_vector (int irq)
 {
-        int pos, vector;
- again:
-        pos = find_first_zero_bit(ia64_vector_mask, IA64_NUM_DEVICE_VECTORS);
-        vector = IA64_FIRST_DEVICE_VECTOR + pos;
-        if (vector > IA64_LAST_DEVICE_VECTOR)
-                return -ENOSPC;
-        if (test_and_set_bit(pos, ia64_vector_mask))
-                goto again;
+        unsigned long flags;
+        int vector = -ENOSPC;
+
+        if (irq < 0) {
+                goto out;
+        }
+        spin_lock_irqsave(&vector_lock, flags);
+        vector = find_unassigned_vector();
+        if (vector < 0)
+                goto out;
+        BUG_ON(__bind_irq_vector(irq, vector));
+        spin_unlock_irqrestore(&vector_lock, flags);
+ out:
         return vector;
 }
 
 void
 free_irq_vector (int vector)
 {
-        int pos;
-
-        if (vector < IA64_FIRST_DEVICE_VECTOR || vector > IA64_LAST_DEVICE_VECTOR)
+        if (vector < IA64_FIRST_DEVICE_VECTOR ||
+            vector > IA64_LAST_DEVICE_VECTOR)
                 return;
-
-        pos = vector - IA64_FIRST_DEVICE_VECTOR;
-        if (!test_and_clear_bit(pos, ia64_vector_mask))
-                printk(KERN_WARNING "%s: double free!\n", __FUNCTION__);
+        clear_irq_vector(vector);
 }
 
 int
 reserve_irq_vector (int vector)
 {
-        int pos;
-
         if (vector < IA64_FIRST_DEVICE_VECTOR ||
             vector > IA64_LAST_DEVICE_VECTOR)
                 return -EINVAL;
+        return !!bind_irq_vector(vector, vector);
+}
 
-        pos = vector - IA64_FIRST_DEVICE_VECTOR;
-        return test_and_set_bit(pos, ia64_vector_mask);
+/*
+ * Initialize vector_irq on a new cpu. This function must be called
+ * with vector_lock held.
+ */
+void __setup_vector_irq(int cpu)
+{
+        int irq, vector;
+
+        /* Clear vector_irq */
+        for (vector = 0; vector < IA64_NUM_VECTORS; ++vector)
+                per_cpu(vector_irq, cpu)[vector] = IA64_SPURIOUS_INT_VECTOR;
+        /* Mark the inuse vectors */
+        for (irq = 0; irq < NR_IRQS; ++irq) {
+                if ((vector = irq_to_vector(irq)) != IRQ_VECTOR_UNASSIGNED)
+                        per_cpu(vector_irq, cpu)[vector] = irq;
+        }
+}
+
+void destroy_and_reserve_irq(unsigned int irq)
+{
+        dynamic_irq_cleanup(irq);
+
+        clear_irq_vector(irq);
+        reserve_irq(irq);
 }
 
 /*
@@ -111,18 +232,29 @@ reserve_irq_vector (int vector)
  */
 int create_irq(void)
 {
-        int vector = assign_irq_vector(AUTO_ASSIGN);
-
-        if (vector >= 0)
-                dynamic_irq_init(vector);
-
-        return vector;
+        unsigned long flags;
+        int irq, vector;
+
+        irq = -ENOSPC;
+        spin_lock_irqsave(&vector_lock, flags);
+        vector = find_unassigned_vector();
+        if (vector < 0)
+                goto out;
+        irq = find_unassigned_irq();
+        if (irq < 0)
+                goto out;
+        BUG_ON(__bind_irq_vector(irq, vector));
+ out:
+        spin_unlock_irqrestore(&vector_lock, flags);
+        if (irq >= 0)
+                dynamic_irq_init(irq);
+        return irq;
 }
 
 void destroy_irq(unsigned int irq)
 {
         dynamic_irq_cleanup(irq);
-        free_irq_vector(irq);
+        clear_irq_vector(irq);
 }
 
 #ifdef CONFIG_SMP
@@ -301,14 +433,13 @@ register_percpu_irq (ia64_vector vec, struct irqaction *action)
         irq_desc_t *desc;
         unsigned int irq;
 
-        for (irq = 0; irq < NR_IRQS; ++irq)
-                if (irq_to_vector(irq) == vec) {
-                        desc = irq_desc + irq;
-                        desc->status |= IRQ_PER_CPU;
-                        desc->chip = &irq_type_ia64_lsapic;
-                        if (action)
-                                setup_irq(irq, action);
-                }
+        irq = vec;
+        BUG_ON(bind_irq_vector(irq, vec));
+        desc = irq_desc + irq;
+        desc->status |= IRQ_PER_CPU;
+        desc->chip = &irq_type_ia64_lsapic;
+        if (action)
+                setup_irq(irq, action);
 }
 
 void __init