Re: [RFC 1/2] PCI-Express Non-Transparent Bridge Support
flat view
From: chetan loke <hidden>
Date: 2012-07-16 18:26:55
Also in:
linux-pci, lkml
Jon, On Fri, Jul 13, 2012 at 5:44 PM, Jon Mason [off-list ref] wrote: ..............
quoted hunk ↗ jump to hunk
+/** + * ntb_ring_sdb() - Set the doorbell on the secondary/external side + * @ndev: pointer to ntb_device instance + * @db: doorbell to ring + * + * This function allows triggering of a doorbell on the secondary/external + * side that will initiate an interrupt on the remote host + * + * RETURNS: An appropriate -ERRNO error value on error, or zero for success. + */ +int ntb_ring_sdb(struct ntb_device *ndev, unsigned int db) +{ + dev_dbg(&ndev->pdev->dev, "%s: ringing doorbell %d\n", __func__, db); +
+ if (db >= ndev->max_cbs) + return -EINVAL;
How about moving this max_cbs error check in the upper level
callers(example in ntb_process_tx)?
That way you won't have to defer handling some negative cases all the
way till the end.
So ntb_process_tx could now look like:
.....
error=0;
if (entry->len > transport_mtu) {
...
error=1;
}
else if (qp->qp_num >= qp->ndev->max_cbs) {
...
error=1;
}
if (unlikely(error)) {
ntb_list_add_tail(&qp->txc_lock, &entry->entry, &qp->txc);
if (qp->tx_handler)
qp->tx_handler(qp);
return 0;
}
.................
No further comments below
quoted hunk ↗ jump to hunk
+ +static int ntb_process_tx(struct ntb_transport_qp *qp, + struct ntb_queue_entry *entry) +{ + struct ntb_payload_header *hdr; + void *offset; + + offset = qp->tx_offset; + hdr = offset; + + pr_debug("%lld - offset %p, tx %p, entry len %d flags %x buff %p\n", + qp->tx_pkts, offset, qp->tx_offset, entry->len, entry->flags, + entry->buf); + if (hdr->flags) { + ntb_list_add_head(&qp->txq_lock, &entry->entry, &qp->txq); + qp->tx_ring_full++; + return -EAGAIN; + } + + if (entry->len > transport_mtu) { + pr_err("Trying to send pkt size of %d\n", entry->len); + entry->flags = HW_ERROR_FLAG; + + ntb_list_add_tail(&qp->txc_lock, &entry->entry, &qp->txc); + + if (qp->tx_handler) + qp->tx_handler(qp); + + return 0; + } + + ntb_tx_copy_task(qp, entry, offset); + + qp->tx_offset = + (qp->tx_offset + + ((transport_mtu + sizeof(struct ntb_payload_header)) * 2) >= + qp->tx_mw_end) ? qp->tx_mw_begin : qp->tx_offset + transport_mtu + + sizeof(struct ntb_payload_header); + + qp->tx_pkts++; + + return 0; +} +
Chetan Loke