1 files changed, 91 insertions, 1 deletions

diff --git a/drivers/scsi/sata_sil.c b/drivers/scsi/sata_sil.c
index f926883fd16c..03c1d1b1a04c 100644
--- a/drivers/scsi/sata_sil.c
+++ b/drivers/scsi/sata_sil.c
@@ -111,6 +111,8 @@ static void sil_dev_config(struct ata_port *ap, struct ata_device *dev);
 static u32 sil_scr_read (struct ata_port *ap, unsigned int sc_reg);
 static void sil_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val);
 static void sil_post_set_mode (struct ata_port *ap);
+static irqreturn_t sil_interrupt(int irq, void *dev_instance,
+                                 struct pt_regs *regs);
 static void sil_freeze(struct ata_port *ap);
 static void sil_thaw(struct ata_port *ap);
 
@@ -196,7 +198,7 @@ static const struct ata_port_operations sil_ops = {
         .thaw                   = sil_thaw,
         .error_handler          = ata_bmdma_error_handler,
         .post_internal_cmd      = ata_bmdma_post_internal_cmd,
-        .irq_handler            = ata_interrupt,
+        .irq_handler            = sil_interrupt,
         .irq_clear              = ata_bmdma_irq_clear,
         .scr_read               = sil_scr_read,
         .scr_write              = sil_scr_write,
@@ -336,6 +338,94 @@ static void sil_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val)
                 writel(val, mmio);
 }
 
+static void sil_host_intr(struct ata_port *ap, u32 bmdma2)
+{
+        struct ata_queued_cmd *qc = ata_qc_from_tag(ap, ap->active_tag);
+        u8 status;
+
+        if (unlikely(!qc || qc->tf.ctl & ATA_NIEN))
+                goto freeze;
+
+        /* Check whether we are expecting interrupt in this state */
+        switch (ap->hsm_task_state) {
+        case HSM_ST_FIRST:
+                /* Some pre-ATAPI-4 devices assert INTRQ
+                 * at this state when ready to receive CDB.
+                 */
+
+                /* Check the ATA_DFLAG_CDB_INTR flag is enough here.
+                 * The flag was turned on only for atapi devices.
+                 * No need to check is_atapi_taskfile(&qc->tf) again.
+                 */
+                if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
+                        goto err_hsm;
+                break;
+        case HSM_ST_LAST:
+                if (qc->tf.protocol == ATA_PROT_DMA ||
+                    qc->tf.protocol == ATA_PROT_ATAPI_DMA) {
+                        /* clear DMA-Start bit */
+                        ap->ops->bmdma_stop(qc);
+
+                        if (bmdma2 & SIL_DMA_ERROR) {
+                                qc->err_mask |= AC_ERR_HOST_BUS;
+                                ap->hsm_task_state = HSM_ST_ERR;
+                        }
+                }
+                break;
+        case HSM_ST:
+                break;
+        default:
+                goto err_hsm;
+        }
+
+        /* check main status, clearing INTRQ */
+        status = ata_chk_status(ap);
+        if (unlikely(status & ATA_BUSY))
+                goto err_hsm;
+
+        /* ack bmdma irq events */
+        ata_bmdma_irq_clear(ap);
+
+        /* kick HSM in the ass */
+        ata_hsm_move(ap, qc, status, 0);
+
+        return;
+
+ err_hsm:
+        qc->err_mask |= AC_ERR_HSM;
+ freeze:
+        ata_port_freeze(ap);
+}
+
+static irqreturn_t sil_interrupt(int irq, void *dev_instance,
+                                 struct pt_regs *regs)
+{
+        struct ata_host_set *host_set = dev_instance;
+        void __iomem *mmio_base = host_set->mmio_base;
+        int handled = 0;
+        int i;
+
+        spin_lock(&host_set->lock);
+
+        for (i = 0; i < host_set->n_ports; i++) {
+                struct ata_port *ap = host_set->ports[i];
+                u32 bmdma2 = readl(mmio_base + sil_port[ap->port_no].bmdma2);
+
+                if (unlikely(!ap || ap->flags & ATA_FLAG_DISABLED))
+                        continue;
+
+                if (!(bmdma2 & SIL_DMA_COMPLETE))
+                        continue;
+
+                sil_host_intr(ap, bmdma2);
+                handled = 1;
+        }
+
+        spin_unlock(&host_set->lock);
+
+        return IRQ_RETVAL(handled);
+}
+
 static void sil_freeze(struct ata_port *ap)
 {
         void __iomem *mmio_base = ap->host_set->mmio_base;