Changeset e3890b3f in mainline for kernel/generic/src/ddi/irq.c

Timestamp:

2006-10-15T12:46:29Z (18 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

2b017ba

Parents:

63530c62

Message:

More IRQ stuff.
Modify the IRQ hash table functions to support lookup based on inr and devno.
Add method member to irq_t.

File:

• kernel/generic/src/ddi/irq.c (modified) (10 diffs)

kernel/generic/src/ddi/irq.c

@@ -32 +32 @@
 /**
  * @file
- * @brief       IRQ redirector.
+ * @brief       IRQ dispatcher.
  *
  * This file provides means of connecting IRQs with particular
@@ -57 +57 @@
  * array. Next, when it is known that the IRQ numbers (aka INR's)
  * are unique, the claim functions can always return IRQ_ACCEPT.
+ *
+ *
+ * Note about the irq_hash_table.
+ *
+ * The hash table is configured to use two keys: inr and devno.
+ * However, the hash index is computed only from inr. Moreover,
+ * if devno is -1, the match is based on the return value of
+ * the claim() function instead of on devno.
  */
 
@@ -67 +75 @@
 #include <arch.h>
 
+#define KEY_INR         0
+#define KEY_DEVNO       1
+
 /**
  * Spinlock protecting the hash table.
@@ -116 +127 @@
          */
         if (inrs == chains)
-                hash_table_create(&irq_hash_table, chains, 1, &irq_lin_ops);
+                hash_table_create(&irq_hash_table, chains, 2, &irq_lin_ops);
         else
-                hash_table_create(&irq_hash_table, chains, 1, &irq_ht_ops);
+                hash_table_create(&irq_hash_table, chains, 2, &irq_ht_ops);
 }
 
@@ -138 +149 @@
         irq->notif_answerbox = NULL;
         irq->code = NULL;
+        irq->method = 0;
         atomic_set(&irq->counter, 0);
 }
@@ -152 +164 @@
 {
         ipl_t ipl;
+        unative_t key[] = {
+                (unative_t) irq->inr,
+                (unative_t) irq->devno
+        };
         
         ipl = interrupts_disable();
         spinlock_lock(&irq_hash_table_lock);
-        hash_table_insert(&irq_hash_table, (void *) &irq->inr, &irq->link);
+        hash_table_insert(&irq_hash_table, key, &irq->link);
         spinlock_unlock(&irq_hash_table_lock);
         interrupts_restore(ipl);
@@ -162 +178 @@
 /** Dispatch the IRQ.
  *
+ * We assume this function is only called from interrupt
+ * context (i.e. that interrupts are disabled prior to
+ * this call).
+ *
+ * This function attempts to lookup a fitting IRQ
+ * structure. In case of success, return with interrupts
+ * disabled and holding the respective structure.
+ *
  * @param inr Interrupt number (aka inr or irq).
  *
  * @return IRQ structure of the respective device or NULL.
  */
-irq_t *irq_dispatch(inr_t inr)
-{
-        ipl_t ipl;
+irq_t *irq_dispatch_and_lock(inr_t inr)
+{
         link_t *lnk;
-        
-        ipl = interrupts_disable();
+        unative_t key[] = {
+                (unative_t) inr,
+                (unative_t) -1          /* search will use claim() instead of devno */
+        };
+        
         spinlock_lock(&irq_hash_table_lock);
 
-        lnk = hash_table_find(&irq_hash_table, (void *) &inr);
+        lnk = hash_table_find(&irq_hash_table, key);
         if (lnk) {
                 irq_t *irq;
@@ -181 +207 @@
 
                 spinlock_unlock(&irq_hash_table_lock);
-                interrupts_restore(ipl);
                 return irq;
         }
         
         spinlock_unlock(&irq_hash_table_lock);
-        interrupts_restore(ipl);
+
+        return NULL;    
+}
+
+/** Find the IRQ structure corresponding to inr and devno.
+ *
+ * This functions attempts to lookup the IRQ structure
+ * corresponding to its arguments. On success, this
+ * function returns with interrups disabled, holding
+ * the lock of the respective IRQ structure.
+ *
+ * This function assumes interrupts are already disabled.
+ *
+ * @param inr INR being looked up.
+ * @param devno Devno being looked up.
+ *
+ * @return Locked IRQ structure on success or NULL on failure.
+ */
+irq_t *irq_find_and_lock(inr_t inr, devno_t devno)
+{
+        link_t *lnk;
+        unative_t keys[] = {
+                (unative_t) inr,
+                (unative_t) devno
+        };
+        
+        spinlock_lock(&irq_hash_table_lock);
+
+        lnk = hash_table_find(&irq_hash_table, keys);
+        if (lnk) {
+                irq_t *irq;
+                
+                irq = hash_table_get_instance(lnk, irq_t, link);
+
+                spinlock_unlock(&irq_hash_table_lock);
+                return irq;
+        }
+        
+        spinlock_unlock(&irq_hash_table_lock);
 
         return NULL;    
@@ -198 +261 @@
  * INRs.
  *
- * @param key Pointer to INR.
+ * The devno is not used to compute the hash.
+ *
+ * @param key The first of the keys is inr and the second is devno or -1.
  *
  * @return Index into the hash table.
  */
-index_t irq_ht_hash(unative_t *key)
-{
-        inr_t *inr = (inr_t *) key;
-        return *inr % irq_hash_table.entries;
+index_t irq_ht_hash(unative_t key[])
+{
+        inr_t inr = (inr_t) key[KEY_INR];
+        return inr % irq_hash_table.entries;
 }
 
 /** Compare hash table element with a key.
  *
- * As usually, we do sort of a hack here.
- * Even when the key matches the inr member,
- * we ask the device to either accept
- * or decline to service the interrupt.
- *
- * @param key Pointer to key (i.e. inr).
- * @param keys This is 1.
+ * There are two things to note about this function.
+ * First, it is used for the more complex architecture setup
+ * in which there are way too many interrupt numbers (i.e. inr's)
+ * to arrange the hash table so that collisions occur only
+ * among same inrs of different devnos. So the explicit check
+ * for inr match must be done.
+ * Second, if devno is -1, the second key (i.e. devno) is not
+ * used for the match and the result of the claim() function
+ * is used instead.
+ *
+ * This function assumes interrupts are already disabled.
+ *
+ * @param key Keys (i.e. inr and devno).
+ * @param keys This is 2.
  * @param item The item to compare the key with.
  *
  * @return True on match or false otherwise.
  */
-bool irq_ht_compare(unative_t *key, count_t keys, link_t *item)
+bool irq_ht_compare(unative_t key[], count_t keys, link_t *item)
 {
         irq_t *irq = hash_table_get_instance(item, irq_t, link);
-        inr_t *inr = (inr_t *) key;
+        inr_t inr = (inr_t) key[KEY_INR];
+        devno_t devno = (devno_t) key[KEY_DEVNO];
+
         bool rv;
         
         spinlock_lock(&irq->lock);
-        rv = ((irq->inr == *inr) && (irq->claim() == IRQ_ACCEPT));
-        spinlock_unlock(&irq->lock);
+        if (devno == -1) {
+                /* Invoked by irq_dispatch(). */
+                rv = ((irq->inr == inr) && (irq->claim() == IRQ_ACCEPT));
+        } else {
+                /* Invoked by irq_find(). */
+                rv = ((irq->inr == inr) && (irq->devno == devno));
+        }
+        
+        /* unlock only on non-match */
+        if (!rv)
+                spinlock_unlock(&irq->lock);
 
         return rv;
@@ -241 +324 @@
  * INRs.
  *
- * @param key INR.
+ * @param key The first of the keys is inr and the second is devno or -1.
  *
  * @return Index into the hash table.
  */
-index_t irq_lin_hash(unative_t *key)
-{
-        inr_t *inr = (inr_t *) key;
-        return *inr;
+index_t irq_lin_hash(unative_t key[])
+{
+        inr_t inr = (inr_t) key[KEY_INR];
+        return inr;
 }
 
 /** Compare hash table element with a key.
  *
- * As usually, we do sort of a hack here.
- * We don't compare the inr member with
- * the key because we know that there are
- * no collision between different keys.
- * We only ask the device to either accept
- * or decline to service the interrupt.
- *
- * @param key Pointer to key (i.e. inr).
- * @param keys This is 1.
+ * There are two things to note about this function.
+ * First, it is used for the less complex architecture setup
+ * in which there are not too many interrupt numbers (i.e. inr's)
+ * to arrange the hash table so that collisions occur only
+ * among same inrs of different devnos. So the explicit check
+ * for inr match is not done.
+ * Second, if devno is -1, the second key (i.e. devno) is not
+ * used for the match and the result of the claim() function
+ * is used instead.
+ *
+ * This function assumes interrupts are already disabled.
+ *
+ * @param key Keys (i.e. inr and devno).
+ * @param keys This is 2.
  * @param item The item to compare the key with.
  *
  * @return True on match or false otherwise.
  */
-bool irq_lin_compare(unative_t *key, count_t keys, link_t *item)
+bool irq_lin_compare(unative_t key[], count_t keys, link_t *item)
 {
         irq_t *irq = list_get_instance(item, irq_t, link);
+        devno_t devno = (devno_t) key[KEY_DEVNO];
         bool rv;
         
         spinlock_lock(&irq->lock);
-        rv = (irq->claim() == IRQ_ACCEPT);
-        spinlock_unlock(&irq->lock);
+        if (devno == -1) {
+                /* Invoked by irq_dispatch() */
+                rv = (irq->claim() == IRQ_ACCEPT);
+        } else {
+                /* Invoked by irq_find() */
+                rv = (irq->devno == devno);
+        }
+        
+        /* unlock only on non-match */
+        if (!rv)
+                spinlock_unlock(&irq->lock);
         
         return rv;