[src/trunk]: src/sys/external/bsd/drm2/dist/drm/i915/gt i915: Fix partial obj...

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

details:   https://anonhg.NetBSD.org/src/rev/be692c388a2d
branches:  trunk
changeset: 1028904:be692c388a2d
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sun Dec 19 12:26:48 2021 +0000

description:
i915: Fix partial object views -- start at the offset.

diffstat:

 sys/external/bsd/drm2/dist/drm/i915/gt/intel_ggtt.c |  23 ++++++++++++++++++--
 1 files changed, 20 insertions(+), 3 deletions(-)

diffs (57 lines):

diff -r edc03871df17 -r be692c388a2d sys/external/bsd/drm2/dist/drm/i915/gt/intel_ggtt.c
--- a/sys/external/bsd/drm2/dist/drm/i915/gt/intel_ggtt.c       Sun Dec 19 12:26:39 2021 +0000
+++ b/sys/external/bsd/drm2/dist/drm/i915/gt/intel_ggtt.c       Sun Dec 19 12:26:48 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: intel_ggtt.c,v 1.11 2021/12/19 12:10:42 riastradh Exp $        */
+/*     $NetBSD: intel_ggtt.c,v 1.12 2021/12/19 12:26:48 riastradh Exp $        */
 
 // SPDX-License-Identifier: MIT
 /*
@@ -6,7 +6,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: intel_ggtt.c,v 1.11 2021/12/19 12:10:42 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: intel_ggtt.c,v 1.12 2021/12/19 12:26:48 riastradh Exp $");
 
 #include <linux/stop_machine.h>
 
@@ -1652,6 +1652,8 @@
         * anything to compress contiguous pages into larger segments.
         */
        if (obj->mm.pages->sgl->sg_dmamap) {
+               bus_size_t offset = (bus_size_t)view->partial.offset
+                   << PAGE_SHIFT;
                unsigned i, j, k;
 
                st->sgl->sg_dmamap->dm_nsegs = view->partial.size;
@@ -1659,13 +1661,28 @@
                        KASSERT(j <= obj->mm.pages->sgl->sg_dmamap->dm_nsegs);
                        const bus_dma_segment_t *iseg =
                            &obj->mm.pages->sgl->sg_dmamap->dm_segs[j];
+
                        KASSERT(iseg->ds_len % PAGE_SIZE == 0);
+
+                       /* Skip segments prior to the start offset.  */
+                       if (offset >= iseg->ds_len) {
+                               offset -= iseg->ds_len;
+                               continue;
+                       }
                        for (k = 0; k < iseg->ds_len >> PAGE_SHIFT; k++) {
                                bus_dma_segment_t *oseg =
                                    &st->sgl->sg_dmamap->dm_segs[i++];
-                               oseg->ds_addr = iseg->ds_addr + k*PAGE_SIZE;
+                               oseg->ds_addr = iseg->ds_addr + offset +
+                                   k*PAGE_SIZE;
                                oseg->ds_len = PAGE_SIZE;
                        }
+
+                       /*
+                        * After the first segment which we possibly
+                        * use only a suffix of, the remainder we will
+                        * take from the beginning.
+                        */
+                       offset = 0;
                }
        }