[RFC PATCH v4 24/38] NTB: ntb_transport: Run ntb_set_mw() before link-up negotiation
Koichiro Den <[email protected]>
| Newsgroups | dev.linux.lists.ntb,dev.linux.lists.iommu,org.kernel.vger.dmaengine,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-doc,org.kernel.vger.linux-kernel,org.kernel.vger.linux-kselftest,org.kernel.vger.linux-pci,org.kernel.vger.linux-renesas-soc,org.kernel.vger.netdev |
|---|---|
| Message-ID | <[email protected]> |
Some backends may need to program BAR subrange mappings, and due to pci_epc_set_bar() submap API constraint, the entire BAR layout needs to be provided when calling the function. Since one MW that is to be programmed by ntb_set_mw() can be the last piece that allows us to call pci_epc_set_bar() for the BAR, calling it only after link-up can race with post-link-up setup on the host. Invoke ntb_set_mw() before the link-up handshake so the MW translation is established early and the post-link-up setup can run without relying on late MW programming. Since ntb_set_mw() can re-setup the MW when it turns out that the size differs, it's safe to do so. Signed-off-by: Koichiro Den <[email protected]> --- drivers/ntb/ntb_transport_core.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/ntb/ntb_transport_core.c b/drivers/ntb/ntb_transport_core.c index 2129fa7a22d8..185d73f8ea93 100644 --- a/drivers/ntb/ntb_transport_core.c +++ b/drivers/ntb/ntb_transport_core.c @@ -977,6 +977,10 @@ static void ntb_transport_link_work(struct work_struct *work) spad = MW0_SZ_LOW + (i * 2); ntb_peer_spad_write(ndev, PIDX, spad, lower_32_bits(size)); + + rc = ntb_set_mw(nt, i, size); + if (rc) + goto out; } ntb_peer_spad_write(ndev, PIDX, NUM_MWS, nt->mw_count); @@ -1032,6 +1036,7 @@ static void ntb_transport_link_work(struct work_struct *work) dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64); + /* If it turns out that the size differs, reconfigure it */ rc = ntb_set_mw(nt, i, val64); if (rc) goto out1; -- 2.51.0