[SCSI] advansys: Improve interrupt handler

Pass the Scsi_Host to the interrupt handler, rather than polling all
hosts for each interrupt.
Return IRQ_NONE if we didn't handle this interrupt
Don't set the IRQF_DISABLED flag; this is not a fast-executing interrupt
handler.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 72 insertions, 100 deletions

diff --git a/drivers/scsi/advansys.c b/drivers/scsi/advansys.c
index 6d11076bbd02..a407ff34199d 100644
--- a/drivers/scsi/advansys.c
+++ b/drivers/scsi/advansys.c
@@ -3951,7 +3951,6 @@ static PortAddr _asc_def_iop_base[];
  * advansys.h contains function prototypes for functions global to Linux.
  */
 
-static irqreturn_t advansys_interrupt(int, void *);
 static int advansys_slave_configure(struct scsi_device *);
 static void asc_scsi_done_list(struct scsi_cmnd *);
 static int asc_execute_scsi_cmnd(struct scsi_cmnd *);
@@ -4684,89 +4683,76 @@ static struct scsi_host_template driver_template = {
  */
 static irqreturn_t advansys_interrupt(int irq, void *dev_id)
 {
-        ulong flags;
-        int i;
-        asc_board_t *boardp;
+        unsigned long flags;
         struct scsi_cmnd *done_scp = NULL, *last_scp = NULL;
         struct scsi_cmnd *new_last_scp;
-        struct Scsi_Host *shost;
+        struct Scsi_Host *shost = dev_id;
+        asc_board_t *boardp = ASC_BOARDP(shost);
+        irqreturn_t result = IRQ_NONE;
 
-        ASC_DBG(1, "advansys_interrupt: begin\n");
+        ASC_DBG1(2, "advansys_interrupt: boardp 0x%p\n", boardp);
+        spin_lock_irqsave(&boardp->lock, flags);
+        if (ASC_NARROW_BOARD(boardp)) {
+                /*
+                 * Narrow Board
+                 */
+                if (AscIsIntPending(shost->io_port)) {
+                        result = IRQ_HANDLED;
+                        ASC_STATS(shost, interrupt);
+                        ASC_DBG(1, "advansys_interrupt: before AscISR()\n");
+                        AscISR(&boardp->dvc_var.asc_dvc_var);
+                }
+        } else {
+                /*
+                 * Wide Board
+                 */
+                ASC_DBG(1, "advansys_interrupt: before AdvISR()\n");
+                if (AdvISR(&boardp->dvc_var.adv_dvc_var)) {
+                        result = IRQ_HANDLED;
+                        ASC_STATS(shost, interrupt);
+                }
+        }
 
         /*
-         * Check for interrupts on all boards.
-         * AscISR() will call asc_isr_callback().
-         */
-        for (i = 0; i < asc_board_count; i++) {
-                shost = asc_host[i];
-                boardp = ASC_BOARDP(shost);
-                ASC_DBG2(2, "advansys_interrupt: i %d, boardp 0x%lx\n",
-                         i, (ulong)boardp);
-                spin_lock_irqsave(&boardp->lock, flags);
-                if (ASC_NARROW_BOARD(boardp)) {
-                        /*
-                         * Narrow Board
-                         */
-                        if (AscIsIntPending(shost->io_port)) {
-                                ASC_STATS(shost, interrupt);
-                                ASC_DBG(1,
-                                        "advansys_interrupt: before AscISR()\n");
-                                AscISR(&boardp->dvc_var.asc_dvc_var);
-                        }
-                } else {
-                        /*
-                         * Wide Board
-                         */
-                        ASC_DBG(1, "advansys_interrupt: before AdvISR()\n");
-                        if (AdvISR(&boardp->dvc_var.adv_dvc_var)) {
-                                ASC_STATS(shost, interrupt);
-                        }
+         * Start waiting requests and create a list of completed requests.
+         *
+         * If a reset request is being performed for the board, the reset
+         * handler will complete pending requests after it has completed.
+         */
+        if ((boardp->flags & ASC_HOST_IN_RESET) == 0) {
+                ASC_DBG2(1, "advansys_interrupt: done_scp 0x%p, "
+                         "last_scp 0x%p\n", done_scp, last_scp);
+
+                /* Start any waiting commands for the board. */
+                if (!ASC_QUEUE_EMPTY(&boardp->waiting)) {
+                        ASC_DBG(1, "advansys_interrupt: before "
+                                "asc_execute_queue()\n");
+                        asc_execute_queue(&boardp->waiting);
                 }
 
                 /*
-                 * Start waiting requests and create a list of completed requests.
+                 * Add to the list of requests that must be completed.
                  *
-                 * If a reset request is being performed for the board, the reset
-                 * handler will complete pending requests after it has completed.
+                 * 'done_scp' will always be NULL on the first iteration of
+                 * this loop. 'last_scp' is set at the same time as 'done_scp'.
                  */
-                if ((boardp->flags & ASC_HOST_IN_RESET) == 0) {
-                        ASC_DBG2(1,
-                                 "advansys_interrupt: done_scp 0x%lx, last_scp 0x%lx\n",
-                                 (ulong)done_scp, (ulong)last_scp);
-
-                        /* Start any waiting commands for the board. */
-                        if (!ASC_QUEUE_EMPTY(&boardp->waiting)) {
-                                ASC_DBG(1,
-                                        "advansys_interrupt: before asc_execute_queue()\n");
-                                asc_execute_queue(&boardp->waiting);
-                        }
-
-                        /*
-                         * Add to the list of requests that must be completed.
-                         *
-                         * 'done_scp' will always be NULL on the first iteration
-                         * of this loop. 'last_scp' is set at the same time as
-                         * 'done_scp'.
-                         */
-                        if (done_scp == NULL) {
-                                done_scp =
-                                    asc_dequeue_list(&boardp->done, &last_scp,
-                                                     ASC_TID_ALL);
-                        } else {
-                                ASC_ASSERT(last_scp != NULL);
-                                last_scp->host_scribble =
-                                    (unsigned char *)asc_dequeue_list(&boardp->
-                                                                      done,
-                                                                      &new_last_scp,
-                                                                      ASC_TID_ALL);
-                                if (new_last_scp != NULL) {
-                                        ASC_ASSERT(REQPNEXT(last_scp) != NULL);
-                                        last_scp = new_last_scp;
-                                }
+                if (done_scp == NULL) {
+                        done_scp = asc_dequeue_list(&boardp->done,
+                                                &last_scp, ASC_TID_ALL);
+                } else {
+                        ASC_ASSERT(last_scp != NULL);
+                        last_scp->host_scribble =
+                            (unsigned char *)asc_dequeue_list(&boardp->
+                                                              done,
+                                                              &new_last_scp,
+                                                              ASC_TID_ALL);
+                        if (new_last_scp != NULL) {
+                                ASC_ASSERT(REQPNEXT(last_scp) != NULL);
+                                last_scp = new_last_scp;
                         }
                 }
-                spin_unlock_irqrestore(&boardp->lock, flags);
         }
+        spin_unlock_irqrestore(&boardp->lock, flags);
 
         /*
          * If interrupts were enabled on entry, then they
@@ -4778,7 +4764,7 @@ static irqreturn_t advansys_interrupt(int irq, void *dev_id)
         asc_scsi_done_list(done_scp);
 
         ASC_DBG(1, "advansys_interrupt: end\n");
-        return IRQ_HANDLED;
+        return result;
 }
 
 /*
@@ -17764,7 +17750,7 @@ advansys_board_found(int iop, struct device *dev, int bus_type)
         ASC_DVC_VAR *asc_dvc_varp = NULL;
         ADV_DVC_VAR *adv_dvc_varp = NULL;
         adv_sgblk_t *sgp = NULL;
-        int share_irq = FALSE;
+        int share_irq;
         int iolen = 0;
         ADV_PADDR pci_memory_address;
         int warn_code, err_code;
@@ -17918,15 +17904,15 @@ advansys_board_found(int iop, struct device *dev, int bus_type)
 #ifdef CONFIG_ISA
                 case ASC_IS_ISA:
                         shost->unchecked_isa_dma = TRUE;
-                        share_irq = FALSE;
+                        share_irq = 0;
                         break;
                 case ASC_IS_VL:
                         shost->unchecked_isa_dma = FALSE;
-                        share_irq = FALSE;
+                        share_irq = 0;
                         break;
                 case ASC_IS_EISA:
                         shost->unchecked_isa_dma = FALSE;
-                        share_irq = TRUE;
+                        share_irq = IRQF_SHARED;
                         break;
 #endif /* CONFIG_ISA */
 #ifdef CONFIG_PCI
@@ -17937,7 +17923,7 @@ advansys_board_found(int iop, struct device *dev, int bus_type)
                                          PCI_SLOT(pdev->devfn),
                                          PCI_FUNC(pdev->devfn));
                         shost->unchecked_isa_dma = FALSE;
-                        share_irq = TRUE;
+                        share_irq = IRQF_SHARED;
                         break;
 #endif /* CONFIG_PCI */
                 default:
@@ -17945,7 +17931,7 @@ advansys_board_found(int iop, struct device *dev, int bus_type)
                             ("advansys_board_found: board %d: unknown adapter type: %d\n",
                              boardp->id, asc_dvc_varp->bus_type);
                         shost->unchecked_isa_dma = TRUE;
-                        share_irq = FALSE;
+                        share_irq = 0;
                         break;
                 }
         } else {
@@ -17961,7 +17947,7 @@ advansys_board_found(int iop, struct device *dev, int bus_type)
                                  PCI_SLOT(pdev->devfn),
                                  PCI_FUNC(pdev->devfn));
                 shost->unchecked_isa_dma = FALSE;
-                share_irq = TRUE;
+                share_irq = IRQF_SHARED;
 #endif /* CONFIG_PCI */
         }
 
@@ -18425,25 +18411,11 @@ advansys_board_found(int iop, struct device *dev, int bus_type)
 
         /* Register IRQ Number. */
         ASC_DBG1(2, "advansys_board_found: request_irq() %d\n", shost->irq);
-        /*
-         * If request_irq() fails with the IRQF_DISABLED flag set,
-         * then try again without the IRQF_DISABLED flag set. This
-         * allows IRQ sharing to work even with other drivers that
-         * do not set the IRQF_DISABLED flag.
-         *
-         * If IRQF_DISABLED is not set, then interrupts are enabled
-         * before the driver interrupt function is called.
-         */
-        if (((ret = request_irq(shost->irq, advansys_interrupt,
-                                IRQF_DISABLED | (share_irq ==
-                                                 TRUE ?
-                                                 IRQF_SHARED :
-                                                 0), "advansys", boardp)) != 0)
-            &&
-            ((ret =
-              request_irq(shost->irq, advansys_interrupt,
-                          (share_irq == TRUE ? IRQF_SHARED : 0),
-                          "advansys", boardp)) != 0)) {
+
+        ret = request_irq(shost->irq, advansys_interrupt, share_irq,
+                          "advansys", shost);
+
+        if (ret) {
                 if (ret == -EBUSY) {
                         ASC_PRINT2
                             ("advansys_board_found: board %d: request_irq(): IRQ 0x%x already in use.\n",
@@ -18644,7 +18616,7 @@ advansys_board_found(int iop, struct device *dev, int bus_type)
 #ifdef CONFIG_PROC_FS
                 kfree(boardp->prtbuf);
 #endif /* CONFIG_PROC_FS */
-                free_irq(shost->irq, boardp);
+                free_irq(shost->irq, shost);
                 scsi_unregister(shost);
                 asc_board_count--;
                 return NULL;
@@ -18960,7 +18932,7 @@ static int advansys_release(struct Scsi_Host *shost)
 
         ASC_DBG(1, "advansys_release: begin\n");
         boardp = ASC_BOARDP(shost);
-        free_irq(shost->irq, boardp);
+        free_irq(shost->irq, shost);
         if (shost->dma_channel != NO_ISA_DMA) {
                 ASC_DBG(1, "advansys_release: free_dma()\n");
                 free_dma(shost->dma_channel);