sata_mv: simplify request/response queue handling
Try and simplify handling of the request/response queues.
Maintain the cached copies of queue indexes in a fully-masked state,
rather than having each use of them have to do the masking.
Split off handling of a single crpb response into a separate function,
to reduce complexity in the main mv_process_crpb_entries() routine.
Ignore the rarely-valid error bits from the crpb status field,
as we already handle that information in mv_err_intr().
For now, preserve the rest of the original logic.
A later patch will deal with fixing that separately.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index 55200685..cee78f9e 100644
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -804,7 +804,8 @@
/*
* initialize request queue
*/
- index = (pp->req_idx & MV_MAX_Q_DEPTH_MASK) << EDMA_REQ_Q_PTR_SHIFT;
+ pp->req_idx &= MV_MAX_Q_DEPTH_MASK; /* paranoia */
+ index = pp->req_idx << EDMA_REQ_Q_PTR_SHIFT;
WARN_ON(pp->crqb_dma & 0x3ff);
writel((pp->crqb_dma >> 16) >> 16, port_mmio + EDMA_REQ_Q_BASE_HI_OFS);
@@ -820,7 +821,8 @@
/*
* initialize response queue
*/
- index = (pp->resp_idx & MV_MAX_Q_DEPTH_MASK) << EDMA_RSP_Q_PTR_SHIFT;
+ pp->resp_idx &= MV_MAX_Q_DEPTH_MASK; /* paranoia */
+ index = pp->resp_idx << EDMA_RSP_Q_PTR_SHIFT;
WARN_ON(pp->crpb_dma & 0xff);
writel((pp->crpb_dma >> 16) >> 16, port_mmio + EDMA_RSP_Q_BASE_HI_OFS);
@@ -1312,7 +1314,7 @@
flags |= (qc->dev->link->pmp & 0xf) << CRQB_PMP_SHIFT;
/* get current queue index from software */
- in_index = pp->req_idx & MV_MAX_Q_DEPTH_MASK;
+ in_index = pp->req_idx;
pp->crqb[in_index].sg_addr =
cpu_to_le32(pp->sg_tbl_dma[qc->tag] & 0xffffffff);
@@ -1404,7 +1406,7 @@
flags |= (qc->dev->link->pmp & 0xf) << CRQB_PMP_SHIFT;
/* get current queue index from software */
- in_index = pp->req_idx & MV_MAX_Q_DEPTH_MASK;
+ in_index = pp->req_idx;
crqb = (struct mv_crqb_iie *) &pp->crqb[in_index];
crqb->addr = cpu_to_le32(pp->sg_tbl_dma[qc->tag] & 0xffffffff);
@@ -1471,9 +1473,8 @@
mv_start_dma(ap, port_mmio, pp, qc->tf.protocol);
- pp->req_idx++;
-
- in_index = (pp->req_idx & MV_MAX_Q_DEPTH_MASK) << EDMA_REQ_Q_PTR_SHIFT;
+ pp->req_idx = (pp->req_idx + 1) & MV_MAX_Q_DEPTH_MASK;
+ in_index = pp->req_idx << EDMA_REQ_Q_PTR_SHIFT;
/* and write the request in pointer to kick the EDMA to life */
writelfl((pp->crqb_dma & EDMA_REQ_Q_BASE_LO_MASK) | in_index,
@@ -1607,70 +1608,72 @@
ata_qc_complete(qc);
}
-static void mv_intr_edma(struct ata_port *ap)
+static void mv_process_crpb_response(struct ata_port *ap,
+ struct mv_crpb *response, unsigned int tag, int ncq_enabled)
+{
+ struct ata_queued_cmd *qc = ata_qc_from_tag(ap, tag);
+
+ if (qc) {
+ u8 ata_status;
+ u16 edma_status = le16_to_cpu(response->flags);
+ /*
+ * edma_status from a response queue entry:
+ * LSB is from EDMA_ERR_IRQ_CAUSE_OFS (non-NCQ only).
+ * MSB is saved ATA status from command completion.
+ */
+ if (!ncq_enabled) {
+ u8 err_cause = edma_status & 0xff & ~EDMA_ERR_DEV;
+ if (err_cause) {
+ /*
+ * Error will be seen/handled by mv_err_intr().
+ * So do nothing at all here.
+ */
+ return;
+ }
+ }
+ ata_status = edma_status >> CRPB_FLAG_STATUS_SHIFT;
+ qc->err_mask |= ac_err_mask(ata_status);
+ ata_qc_complete(qc);
+ } else {
+ ata_port_printk(ap, KERN_ERR, "%s: no qc for tag=%d\n",
+ __func__, tag);
+ }
+}
+
+static void mv_process_crpb_entries(struct ata_port *ap, struct mv_port_priv *pp)
{
void __iomem *port_mmio = mv_ap_base(ap);
struct mv_host_priv *hpriv = ap->host->private_data;
- struct mv_port_priv *pp = ap->private_data;
- struct ata_queued_cmd *qc;
- u32 out_index, in_index;
+ u32 in_index;
bool work_done = false;
+ int ncq_enabled = (pp->pp_flags & MV_PP_FLAG_NCQ_EN);
- /* get h/w response queue pointer */
+ /* Get the hardware queue position index */
in_index = (readl(port_mmio + EDMA_RSP_Q_IN_PTR_OFS)
>> EDMA_RSP_Q_PTR_SHIFT) & MV_MAX_Q_DEPTH_MASK;
- while (1) {
- u16 status;
+ /* Process new responses from since the last time we looked */
+ while (in_index != pp->resp_idx) {
unsigned int tag;
+ struct mv_crpb *response = &pp->crpb[pp->resp_idx];
- /* get s/w response queue last-read pointer, and compare */
- out_index = pp->resp_idx & MV_MAX_Q_DEPTH_MASK;
- if (in_index == out_index)
- break;
+ pp->resp_idx = (pp->resp_idx + 1) & MV_MAX_Q_DEPTH_MASK;
- /* 50xx: get active ATA command */
- if (IS_GEN_I(hpriv))
+ if (IS_GEN_I(hpriv)) {
+ /* 50xx: no NCQ, only one command active at a time */
tag = ap->link.active_tag;
-
- /* Gen II/IIE: get active ATA command via tag, to enable
- * support for queueing. this works transparently for
- * queued and non-queued modes.
- */
- else
- tag = le16_to_cpu(pp->crpb[out_index].id) & 0x1f;
-
- qc = ata_qc_from_tag(ap, tag);
-
- /* For non-NCQ mode, the lower 8 bits of status
- * are from EDMA_ERR_IRQ_CAUSE_OFS,
- * which should be zero if all went well.
- */
- status = le16_to_cpu(pp->crpb[out_index].flags);
- if ((status & 0xff) && !(pp->pp_flags & MV_PP_FLAG_NCQ_EN)) {
- mv_err_intr(ap, qc);
- return;
+ } else {
+ /* Gen II/IIE: get command tag from CRPB entry */
+ tag = le16_to_cpu(response->id) & 0x1f;
}
-
- /* and finally, complete the ATA command */
- if (qc) {
- qc->err_mask |=
- ac_err_mask(status >> CRPB_FLAG_STATUS_SHIFT);
- ata_qc_complete(qc);
- }
-
- /* advance software response queue pointer, to
- * indicate (after the loop completes) to hardware
- * that we have consumed a response queue entry.
- */
+ mv_process_crpb_response(ap, response, tag, ncq_enabled);
work_done = true;
- pp->resp_idx++;
}
/* Update the software queue position index in hardware */
if (work_done)
writelfl((pp->crpb_dma & EDMA_RSP_Q_BASE_LO_MASK) |
- (out_index << EDMA_RSP_Q_PTR_SHIFT),
+ (pp->resp_idx << EDMA_RSP_Q_PTR_SHIFT),
port_mmio + EDMA_RSP_Q_OUT_PTR_OFS);
}
@@ -1748,7 +1751,7 @@
if (pp->pp_flags & MV_PP_FLAG_EDMA_EN) {
if ((DMA_IRQ << hardport) & hc_irq_cause)
- mv_intr_edma(ap);
+ mv_process_crpb_entries(ap, pp);
} else {
if ((DEV_IRQ << hardport) & hc_irq_cause)
mv_intr_pio(ap);