[src/trunk]: src/sys/dev/pci Upon further reflection, we actually do need to ...

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a0b5d4e9de8f
branches:  trunk
changeset: 745383:a0b5d4e9de8f
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Sun Mar 01 03:06:08 2020 +0000

description:
Upon further reflection, we actually do need to ensure that the Rx
ring and the Rx Return ring are both in the same 4GB segment.

diffstat:

 sys/dev/pci/if_alc.c |  26 ++++++++++++++++++--------
 1 files changed, 18 insertions(+), 8 deletions(-)

diffs (47 lines):

diff -r 90b5521fa21a -r a0b5d4e9de8f sys/dev/pci/if_alc.c
--- a/sys/dev/pci/if_alc.c      Sun Mar 01 03:00:31 2020 +0000
+++ b/sys/dev/pci/if_alc.c      Sun Mar 01 03:06:08 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_alc.c,v 1.51 2020/03/01 03:00:31 thorpej Exp $      */
+/*     $NetBSD: if_alc.c,v 1.52 2020/03/01 03:06:08 thorpej Exp $      */
 /*     $OpenBSD: if_alc.c,v 1.1 2009/08/08 09:31:13 kevlo Exp $        */
 /*-
  * Copyright (c) 2009, Pyun YongHyeon <yongari%FreeBSD.org@localhost>
@@ -1614,13 +1614,6 @@
            sc->alc_cdata.alc_tx_ring_map->dm_segs[0].ds_addr;
 
        /*
-        * NOTE: If we used more than one Rx / Rx Return ring,
-        * we would need to ensure ALL of the Rx-related stuff
-        * ended up in the same 4G segment, since the hardware
-        * requires this.
-        */
-
-       /*
         * Create DMA stuffs for RX ring
         */
        error = bus_dmamap_create(sc->sc_dmat, ALC_RX_RING_SZ, 1,
@@ -1697,6 +1690,23 @@
            sc->alc_cdata.alc_rr_ring_map->dm_segs[0].ds_addr;
 
        /*
+        * All of the memory we allocated for the Rx ring / Rx Return
+        * ring need to be in the same 4GB segment.  Make sure this is
+        * so.
+        *
+        * XXX We don't care WHAT 4GB segment they're in, just that
+        * XXX they're all in the same one.  Need some bus_dma API
+        * XXX help to make this easier to enforce when we actually
+        * XXX perform the allocation.
+        */
+       if (ALC_ADDR_HI(sc->alc_rdata.alc_rx_ring_paddr) !=
+           ALC_ADDR_HI(sc->alc_rdata.alc_rr_ring_paddr)) {
+               aprint_error_dev(sc->sc_dev,
+                   "Rx control data allocation constraints failed\n");
+               return ENOBUFS;
+       }
+
+       /*
         * Create DMA stuffs for CMB block
         */
        error = bus_dmamap_create(sc->sc_dmat, ALC_CMB_SZ, 1,