[v3,4/8] NTB: ntb_pingpong: Choose doorbells based on port number
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Message ID 20190109192233.5752-5-logang@deltatee.com
State In Next
Commit 40e23fa9d8fca3d292a508d2ff793ae7a9914d55
Headers show
Series
  • Fix breakage caused by the NTB multi-port patchset
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Commit Message

Logan Gunthorpe Jan. 9, 2019, 7:22 p.m. UTC
This commit fixes pingpong support for existing drivers that do not
implement ntb_default_port_number() and ntb_default_peer_port_number().
This is required for hardware (like the crosslink topology of
switchtec) which cannot assign reasonable port numbers to each port due
to its perfect symmetry.

Instead of picking the doorbell to use based on the the index of the
peer, we use the peer's port number. This is a bit clearer and easier
to understand.

Fixes: c7aeb0afdcc2 ("NTB: ntb_pp: Add full multi-port NTB API support")
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Allen Hubbe <allenbh@gmail.com>
Tested-by: Alexander Fomichev <fomichev.ru@gmail.com>
---
 drivers/ntb/test/ntb_pingpong.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

Patch
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diff --git a/drivers/ntb/test/ntb_pingpong.c b/drivers/ntb/test/ntb_pingpong.c
index 65865e460ab8..18d00eec7b02 100644
--- a/drivers/ntb/test/ntb_pingpong.c
+++ b/drivers/ntb/test/ntb_pingpong.c
@@ -121,15 +121,14 @@  static int pp_find_next_peer(struct pp_ctx *pp)
 	link = ntb_link_is_up(pp->ntb, NULL, NULL);
 
 	/* Find next available peer */
-	if (link & pp->nmask) {
+	if (link & pp->nmask)
 		pidx = __ffs64(link & pp->nmask);
-		out_db = BIT_ULL(pidx + 1);
-	} else if (link & pp->pmask) {
+	else if (link & pp->pmask)
 		pidx = __ffs64(link & pp->pmask);
-		out_db = BIT_ULL(pidx);
-	} else {
+	else
 		return -ENODEV;
-	}
+
+	out_db = BIT_ULL(ntb_peer_port_number(pp->ntb, pidx));
 
 	spin_lock(&pp->lock);
 	pp->out_pidx = pidx;
@@ -303,7 +302,7 @@  static void pp_init_flds(struct pp_ctx *pp)
 			break;
 	}
 
-	pp->in_db = BIT_ULL(pidx);
+	pp->in_db = BIT_ULL(lport);
 	pp->pmask = GENMASK_ULL(pidx, 0) >> 1;
 	pp->nmask = GENMASK_ULL(pcnt - 1, pidx);
 
@@ -435,4 +434,3 @@  static void __exit pp_exit(void)
 	debugfs_remove_recursive(pp_dbgfs_topdir);
 }
 module_exit(pp_exit);
-