[IA64] Cleanup lock order in iosapic_register_intr

Cleanup order of irq_desc.lock and iosapic_lock in
iosapic_register_intr() and iosapic_unregister_intr().

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, 20 insertions, 30 deletions

diff --git a/arch/ia64/kernel/iosapic.c b/arch/ia64/kernel/iosapic.c
index 29ec86c24194..b3dcdb7e7fc7 100644
--- a/arch/ia64/kernel/iosapic.c
+++ b/arch/ia64/kernel/iosapic.c
@@ -505,7 +505,7 @@ iosapic_version (char __iomem *addr)
 static int iosapic_find_sharable_vector (unsigned long trigger,
                                          unsigned long pol)
 {
-        int i, vector = -1, min_count = -1;
+        int i, vector = -ENOSPC, min_count = -1;
         struct iosapic_intr_info *info;
 
         /*
@@ -513,7 +513,7 @@ static int iosapic_find_sharable_vector (unsigned long trigger,
          * supported yet
          */
         if (trigger == IOSAPIC_EDGE)
-                return -1;
+                return -EINVAL;
 
         for (i = IA64_FIRST_DEVICE_VECTOR; i <= IA64_LAST_DEVICE_VECTOR; i++) {
                 info = &iosapic_intr_info[i];
@@ -762,7 +762,7 @@ iosapic_register_intr (unsigned int gsi,
         unsigned long flags;
         struct iosapic_rte_info *rte;
         u32 low32;
-again:
+
         /*
          * If this GSI has already been registered (i.e., it's a
          * shared interrupt, or we lost a race to register it),
@@ -773,36 +773,24 @@ again:
         if (vector > 0) {
                 rte = gsi_vector_to_rte(gsi, vector);
                 rte->refcnt++;
-                spin_unlock_irqrestore(&iosapic_lock, flags);
-                return vector;
+                goto unlock_iosapic_lock;
         }
-        spin_unlock_irqrestore(&iosapic_lock, flags);
 
         /* If vector is running out, we try to find a sharable vector */
         vector = assign_irq_vector(AUTO_ASSIGN);
         if (vector < 0) {
                 vector = iosapic_find_sharable_vector(trigger, polarity);
                 if (vector < 0)
-                        return -ENOSPC;
-        }
-
-        spin_lock_irqsave(&irq_desc[vector].lock, flags);
-        spin_lock(&iosapic_lock);
-        if (gsi_to_vector(gsi) > 0) {
-                if (list_empty(&iosapic_intr_info[vector].rtes))
-                        free_irq_vector(vector);
-                spin_unlock(&iosapic_lock);
-                spin_unlock_irqrestore(&irq_desc[vector].lock, flags);
-                goto again;
+                        goto unlock_iosapic_lock;
         }
 
+        spin_lock(&irq_desc[vector].lock);
         dest = get_target_cpu(gsi, vector);
         err = register_intr(gsi, vector, IOSAPIC_LOWEST_PRIORITY,
                             polarity, trigger);
         if (err < 0) {
-                spin_unlock(&iosapic_lock);
-                spin_unlock_irqrestore(&irq_desc[vector].lock, flags);
-                return err;
+                vector = err;
+                goto unlock_all;
         }
 
         /*
@@ -813,14 +801,15 @@ again:
         if (vector_is_shared(vector) && !(low32 & IOSAPIC_MASK))
                 mask = 0;
         set_rte(gsi, vector, dest, mask);
-        spin_unlock(&iosapic_lock);
-        spin_unlock_irqrestore(&irq_desc[vector].lock, flags);
 
         printk(KERN_INFO "GSI %u (%s, %s) -> CPU %d (0x%04x) vector %d\n",
                gsi, (trigger == IOSAPIC_EDGE ? "edge" : "level"),
                (polarity == IOSAPIC_POL_HIGH ? "high" : "low"),
                cpu_logical_id(dest), dest, vector);
-
+ unlock_all:
+        spin_unlock(&irq_desc[vector].lock);
+ unlock_iosapic_lock:
+        spin_unlock_irqrestore(&iosapic_lock, flags);
         return vector;
 }
 
@@ -849,9 +838,7 @@ iosapic_unregister_intr (unsigned int gsi)
         }
         vector = irq_to_vector(irq);
 
-        idesc = irq_desc + irq;
-        spin_lock_irqsave(&idesc->lock, flags);
-        spin_lock(&iosapic_lock);
+        spin_lock_irqsave(&iosapic_lock, flags);
         if ((rte = gsi_vector_to_rte(gsi, vector)) == NULL) {
                 printk(KERN_ERR "iosapic_unregister_intr(%u) unbalanced\n",
                        gsi);
@@ -862,13 +849,17 @@ iosapic_unregister_intr (unsigned int gsi)
         if (--rte->refcnt > 0)
                 goto out;
 
+        /* Remove the rte entry from the list */
+        idesc = irq_desc + irq;
+        spin_lock(&idesc->lock);
+        list_del(&rte->rte_list);
+        spin_unlock(&idesc->lock);
+
         /* Mask the interrupt */
         low32 = iosapic_intr_info[vector].low32 | IOSAPIC_MASK;
         iosapic_write(rte->iosapic->addr,
                       IOSAPIC_RTE_LOW(rte->rte_index), low32);
 
-        /* Remove the rte entry from the list */
-        list_del(&rte->rte_list);
         iosapic_intr_info[vector].count--;
         iosapic_free_rte(rte);
         index = find_iosapic(gsi);
@@ -913,8 +904,7 @@ iosapic_unregister_intr (unsigned int gsi)
                 free_irq_vector(vector);
         }
  out:
-        spin_unlock(&iosapic_lock);
-        spin_unlock_irqrestore(&idesc->lock, flags);
+        spin_unlock_irqrestore(&iosapic_lock, flags);
 }
 
 /*