[PATCH] libata-eh: implement BMDMA EH

Implement stock BMDMA error handling methods.

Signed-off-by: Tejun Heo <htejun@gmail.com>

3 files changed, 157 insertions, 0 deletions

diff --git a/drivers/scsi/libata-bmdma.c b/drivers/scsi/libata-bmdma.c
index 835dff0bafdc..49eff18a67e3 100644
--- a/drivers/scsi/libata-bmdma.c
+++ b/drivers/scsi/libata-bmdma.c
@@ -652,6 +652,150 @@ void ata_bmdma_stop(struct ata_queued_cmd *qc)
         ata_altstatus(ap);        /* dummy read */
 }
 
+/**
+ *      ata_bmdma_freeze - Freeze BMDMA controller port
+ *      @ap: port to freeze
+ *
+ *      Freeze BMDMA controller port.
+ *
+ *      LOCKING:
+ *      Inherited from caller.
+ */
+void ata_bmdma_freeze(struct ata_port *ap)
+{
+        struct ata_ioports *ioaddr = &ap->ioaddr;
+
+        ap->ctl |= ATA_NIEN;
+        ap->last_ctl = ap->ctl;
+
+        if (ap->flags & ATA_FLAG_MMIO)
+                writeb(ap->ctl, (void __iomem *)ioaddr->ctl_addr);
+        else
+                outb(ap->ctl, ioaddr->ctl_addr);
+}
+
+/**
+ *      ata_bmdma_thaw - Thaw BMDMA controller port
+ *      @ap: port to thaw
+ *
+ *      Thaw BMDMA controller port.
+ *
+ *      LOCKING:
+ *      Inherited from caller.
+ */
+void ata_bmdma_thaw(struct ata_port *ap)
+{
+        /* clear & re-enable interrupts */
+        ata_chk_status(ap);
+        ap->ops->irq_clear(ap);
+        if (ap->ioaddr.ctl_addr)        /* FIXME: hack. create a hook instead */
+                ata_irq_on(ap);
+}
+
+/**
+ *      ata_bmdma_drive_eh - Perform EH with given methods for BMDMA controller
+ *      @ap: port to handle error for
+ *      @softreset: softreset method (can be NULL)
+ *      @hardreset: hardreset method (can be NULL)
+ *      @postreset: postreset method (can be NULL)
+ *
+ *      Handle error for ATA BMDMA controller.  It can handle both
+ *      PATA and SATA controllers.  Many controllers should be able to
+ *      use this EH as-is or with some added handling before and
+ *      after.
+ *
+ *      This function is intended to be used for constructing
+ *      ->error_handler callback by low level drivers.
+ *
+ *      LOCKING:
+ *      Kernel thread context (may sleep)
+ */
+void ata_bmdma_drive_eh(struct ata_port *ap, ata_reset_fn_t softreset,
+                        ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
+{
+        struct ata_host_set *host_set = ap->host_set;
+        struct ata_eh_context *ehc = &ap->eh_context;
+        struct ata_queued_cmd *qc;
+        unsigned long flags;
+        int thaw = 0;
+
+        qc = __ata_qc_from_tag(ap, ap->active_tag);
+        if (qc && !(qc->flags & ATA_QCFLAG_FAILED))
+                qc = NULL;
+
+        /* reset PIO HSM and stop DMA engine */
+        spin_lock_irqsave(&host_set->lock, flags);
+
+        ap->flags &= ~ATA_FLAG_NOINTR;
+        ap->hsm_task_state = HSM_ST_IDLE;
+
+        if (qc && (qc->tf.protocol == ATA_PROT_DMA ||
+                   qc->tf.protocol == ATA_PROT_ATAPI_DMA)) {
+                u8 host_stat;
+
+                host_stat = ata_bmdma_status(ap);
+
+                ata_ehi_push_desc(&ehc->i, "BMDMA stat 0x%x", host_stat);
+
+                /* BMDMA controllers indicate host bus error by
+                 * setting DMA_ERR bit and timing out.  As it wasn't
+                 * really a timeout event, adjust error mask and
+                 * cancel frozen state.
+                 */
+                if (qc->err_mask == AC_ERR_TIMEOUT && host_stat & ATA_DMA_ERR) {
+                        qc->err_mask = AC_ERR_HOST_BUS;
+                        thaw = 1;
+                }
+
+                ap->ops->bmdma_stop(qc);
+        }
+
+        ata_altstatus(ap);
+        ata_chk_status(ap);
+        ap->ops->irq_clear(ap);
+
+        spin_unlock_irqrestore(&host_set->lock, flags);
+
+        if (thaw)
+                ata_eh_thaw_port(ap);
+
+        /* PIO and DMA engines have been stopped, perform recovery */
+        ata_do_eh(ap, softreset, hardreset, postreset);
+}
+
+/**
+ *      ata_bmdma_error_handler - Stock error handler for BMDMA controller
+ *      @ap: port to handle error for
+ *
+ *      Stock error handler for BMDMA controller.
+ *
+ *      LOCKING:
+ *      Kernel thread context (may sleep)
+ */
+void ata_bmdma_error_handler(struct ata_port *ap)
+{
+        ata_reset_fn_t hardreset;
+
+        hardreset = NULL;
+        if (sata_scr_valid(ap))
+                hardreset = sata_std_hardreset;
+
+        ata_bmdma_drive_eh(ap, ata_std_softreset, hardreset, ata_std_postreset);
+}
+
+/**
+ *      ata_bmdma_post_internal_cmd - Stock post_internal_cmd for
+ *                                    BMDMA controller
+ *      @qc: internal command to clean up
+ *
+ *      LOCKING:
+ *      Kernel thread context (may sleep)
+ */
+void ata_bmdma_post_internal_cmd(struct ata_queued_cmd *qc)
+{
+        ata_bmdma_stop(qc);
+}
+
 #ifdef CONFIG_PCI
 static struct ata_probe_ent *
 ata_probe_ent_alloc(struct device *dev, const struct ata_port_info *port)
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index ddc47097d37e..2969599ec0b9 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -5377,6 +5377,11 @@ EXPORT_SYMBOL_GPL(ata_bmdma_start);
 EXPORT_SYMBOL_GPL(ata_bmdma_irq_clear);
 EXPORT_SYMBOL_GPL(ata_bmdma_status);
 EXPORT_SYMBOL_GPL(ata_bmdma_stop);
+EXPORT_SYMBOL_GPL(ata_bmdma_freeze);
+EXPORT_SYMBOL_GPL(ata_bmdma_thaw);
+EXPORT_SYMBOL_GPL(ata_bmdma_drive_eh);
+EXPORT_SYMBOL_GPL(ata_bmdma_error_handler);
+EXPORT_SYMBOL_GPL(ata_bmdma_post_internal_cmd);
 EXPORT_SYMBOL_GPL(ata_port_probe);
 EXPORT_SYMBOL_GPL(sata_set_spd);
 EXPORT_SYMBOL_GPL(sata_phy_reset);
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 9fe46073cf8c..6ccacbf889e3 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -661,6 +661,14 @@ extern void ata_bmdma_start (struct ata_queued_cmd *qc);
 extern void ata_bmdma_stop(struct ata_queued_cmd *qc);
 extern u8   ata_bmdma_status(struct ata_port *ap);
 extern void ata_bmdma_irq_clear(struct ata_port *ap);
+extern void ata_bmdma_freeze(struct ata_port *ap);
+extern void ata_bmdma_thaw(struct ata_port *ap);
+extern void ata_bmdma_drive_eh(struct ata_port *ap,
+                               ata_reset_fn_t softreset,
+                               ata_reset_fn_t hardreset,
+                               ata_postreset_fn_t postreset);
+extern void ata_bmdma_error_handler(struct ata_port *ap);
+extern void ata_bmdma_post_internal_cmd(struct ata_queued_cmd *qc);
 extern void ata_qc_complete(struct ata_queued_cmd *qc);
 extern void ata_scsi_simulate(struct ata_device *dev, struct scsi_cmnd *cmd,
                               void (*done)(struct scsi_cmnd *));