isci: kill isci_host list in favor of an array

isci_host_by_id() should have been a clue that an array would have been
a simpler approach.
Reported-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

drivers/scsi/isci/host.c

@@ -78,8 +78,9 @@ irqreturn_t isci_intx_isr(int vec, void *data)
 	struct pci_dev *pdev = data;
 	struct isci_host *ihost;
 	irqreturn_t ret = IRQ_NONE;
+	int i;
 
-	for_each_isci_host(ihost, pdev) {
+	for_each_isci_host(i, ihost, pdev) {
 		struct scic_sds_controller *scic = ihost->core_controller;
 
 		if (scic_sds_controller_isr(scic)) {

drivers/scsi/isci/host.h

@@ -117,7 +117,6 @@ struct isci_host {
 	struct list_head requests_to_complete;
 	struct list_head requests_to_abort;
 	spinlock_t scic_lock;
-	struct isci_host *next;
 };
 
 
@@ -131,7 +130,7 @@ struct isci_host {
 struct isci_pci_info {
 	struct msix_entry msix_entries[SCI_MAX_MSIX_INT];
 	int core_lib_array_index;
-	struct isci_host *hosts;
+	struct isci_host *hosts[SCI_MAX_CONTROLLERS];
 };
 
 static inline struct isci_pci_info *to_pci_info(struct pci_dev *pdev)
@@ -139,9 +138,10 @@ static inline struct isci_pci_info *to_pci_info(struct pci_dev *pdev)
 	return pci_get_drvdata(pdev);
 }
 
-#define for_each_isci_host(isci_host, pdev) \
-	for (isci_host = to_pci_info(pdev)->hosts;\
-	     isci_host; isci_host = isci_host->next)
+#define for_each_isci_host(id, ihost, pdev) \
+	for (id = 0, ihost = to_pci_info(pdev)->hosts[id]; \
+	     id < ARRAY_SIZE(to_pci_info(pdev)->hosts) && ihost; \
+	     ihost = to_pci_info(pdev)->hosts[++id])
 
 static inline
 enum isci_status isci_host_get_state(

drivers/scsi/isci/init.c

@@ -285,16 +285,6 @@ static int __devinit isci_pci_init(struct pci_dev *pdev)
 	return 0;
 }
 
-static struct isci_host *isci_host_by_id(struct pci_dev *pdev, int id)
-{
-	struct isci_host *h;
-
-	for_each_isci_host(h, pdev)
-		if (h->id == id)
-			return h;
-	return NULL;
-}
-
 static int num_controllers(struct pci_dev *pdev)
 {
 	/* bar size alone can tell us if we are running with a dual controller
@@ -332,7 +322,7 @@ static int isci_setup_interrupts(struct pci_dev *pdev)
 	for (i = 0; i < num_msix; i++) {
 		int id = i / SCI_NUM_MSI_X_INT;
 		struct msix_entry *msix = &pci_info->msix_entries[i];
-		struct isci_host *isci_host = isci_host_by_id(pdev, id);
+		struct isci_host *isci_host = pci_info->hosts[id];
 		irq_handler_t isr;
 
 		/* odd numbered vectors are error interrupts */
@@ -351,7 +341,7 @@ static int isci_setup_interrupts(struct pci_dev *pdev)
 		dev_info(&pdev->dev, "msix setup failed falling back to intx\n");
 		while (i--) {
 			id = i / SCI_NUM_MSI_X_INT;
-			isci_host = isci_host_by_id(pdev, id);
+			isci_host = pci_info->hosts[id];
 			msix = &pci_info->msix_entries[i];
 			devm_free_irq(&pdev->dev, msix->vector, isci_host);
 		}
@@ -634,22 +624,20 @@ static int __devinit isci_pci_probe(struct pci_dev *pdev, const struct pci_devic
 			err = -ENOMEM;
 			goto err_host_alloc;
 		}
-
-		h->next = pci_info->hosts;
-		pci_info->hosts = h;
+		pci_info->hosts[i] = h;
 	}
 
 	err = isci_setup_interrupts(pdev);
 	if (err)
 		goto err_host_alloc;
 
-	for_each_isci_host(isci_host, pdev)
+	for_each_isci_host(i, isci_host, pdev)
 		scsi_scan_host(isci_host->shost);
 
 	return 0;
 
  err_host_alloc:
-	for_each_isci_host(isci_host, pdev)
+	for_each_isci_host(i, isci_host, pdev)
 		isci_unregister_sas_ha(isci_host);
 	return err;
 }
@@ -657,8 +645,9 @@ static int __devinit isci_pci_probe(struct pci_dev *pdev, const struct pci_devic
 static void __devexit isci_pci_remove(struct pci_dev *pdev)
 {
 	struct isci_host *isci_host;
+	int i;
 
-	for_each_isci_host(isci_host, pdev) {
+	for_each_isci_host(i, isci_host, pdev) {
 		isci_unregister_sas_ha(isci_host);
 		isci_host_deinit(isci_host);
 		scic_controller_disable_interrupts(isci_host->core_controller);