drm/radeon: fix support for vline relocations.

Userspace sends us a special relocation type to sync video/exa
to vlines to avoid tearing, this deals with the relocation
in the kernel, it picks the correct crtc and avoids issues
where crtcs are disabled.

This version also parses the wait until to make sure it isn't
trying to do anything evil.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 105 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
index a3db56bb013..154648a2c02 100644
--- a/drivers/gpu/drm/radeon/r100.c
+++ b/drivers/gpu/drm/radeon/r100.c
@@ -752,6 +752,102 @@ int r100_cs_packet_parse(struct radeon_cs_parser *p,
 }
 
 /**
+ * r100_cs_packet_next_vline() - parse userspace VLINE packet
+ * @parser:		parser structure holding parsing context.
+ *
+ * Userspace sends a special sequence for VLINE waits.
+ * PACKET0 - VLINE_START_END + value
+ * PACKET0 - WAIT_UNTIL +_value
+ * RELOC (P3) - crtc_id in reloc.
+ *
+ * This function parses this and relocates the VLINE START END
+ * and WAIT UNTIL packets to the correct crtc.
+ * It also detects a switched off crtc and nulls out the
+ * wait in that case.
+ */
+int r100_cs_packet_parse_vline(struct radeon_cs_parser *p)
+{
+	struct radeon_cs_chunk *ib_chunk;
+	struct drm_mode_object *obj;
+	struct drm_crtc *crtc;
+	struct radeon_crtc *radeon_crtc;
+	struct radeon_cs_packet p3reloc, waitreloc;
+	int crtc_id;
+	int r;
+	uint32_t header, h_idx, reg;
+
+	ib_chunk = &p->chunks[p->chunk_ib_idx];
+
+	/* parse the wait until */
+	r = r100_cs_packet_parse(p, &waitreloc, p->idx);
+	if (r)
+		return r;
+
+	/* check its a wait until and only 1 count */
+	if (waitreloc.reg != RADEON_WAIT_UNTIL ||
+	    waitreloc.count != 0) {
+		DRM_ERROR("vline wait had illegal wait until segment\n");
+		r = -EINVAL;
+		return r;
+	}
+
+	if (ib_chunk->kdata[waitreloc.idx + 1] != RADEON_WAIT_CRTC_VLINE) {
+		DRM_ERROR("vline wait had illegal wait until\n");
+		r = -EINVAL;
+		return r;
+	}
+
+	/* jump over the NOP */
+	r = r100_cs_packet_parse(p, &p3reloc, p->idx);
+	if (r)
+		return r;
+
+	h_idx = p->idx - 2;
+	p->idx += waitreloc.count;
+	p->idx += p3reloc.count;
+
+	header = ib_chunk->kdata[h_idx];
+	crtc_id = ib_chunk->kdata[h_idx + 5];
+	reg = ib_chunk->kdata[h_idx] >> 2;
+	mutex_lock(&p->rdev->ddev->mode_config.mutex);
+	obj = drm_mode_object_find(p->rdev->ddev, crtc_id, DRM_MODE_OBJECT_CRTC);
+	if (!obj) {
+		DRM_ERROR("cannot find crtc %d\n", crtc_id);
+		r = -EINVAL;
+		goto out;
+	}
+	crtc = obj_to_crtc(obj);
+	radeon_crtc = to_radeon_crtc(crtc);
+	crtc_id = radeon_crtc->crtc_id;
+
+	if (!crtc->enabled) {
+		/* if the CRTC isn't enabled - we need to nop out the wait until */
+		ib_chunk->kdata[h_idx + 2] = PACKET2(0);
+		ib_chunk->kdata[h_idx + 3] = PACKET2(0);
+	} else if (crtc_id == 1) {
+		switch (reg) {
+		case AVIVO_D1MODE_VLINE_START_END:
+			header &= R300_CP_PACKET0_REG_MASK;
+			header |= AVIVO_D2MODE_VLINE_START_END >> 2;
+			break;
+		case RADEON_CRTC_GUI_TRIG_VLINE:
+			header &= R300_CP_PACKET0_REG_MASK;
+			header |= RADEON_CRTC2_GUI_TRIG_VLINE >> 2;
+			break;
+		default:
+			DRM_ERROR("unknown crtc reloc\n");
+			r = -EINVAL;
+			goto out;
+		}
+		ib_chunk->kdata[h_idx] = header;
+		ib_chunk->kdata[h_idx + 3] |= RADEON_ENG_DISPLAY_SELECT_CRTC1;
+	}
+out:
+	mutex_unlock(&p->rdev->ddev->mode_config.mutex);
+	return r;
+}
+
+/**
  * r100_cs_packet_next_reloc() - parse next packet which should be reloc packet3
  * @parser:		parser structure holding parsing context.
  * @data:		pointer to relocation data
@@ -824,6 +920,15 @@ static int r100_packet0_check(struct radeon_cs_parser *p,
 	}
 	for (i = 0; i <= pkt->count; i++, idx++, reg += 4) {
 		switch (reg) {
+		case RADEON_CRTC_GUI_TRIG_VLINE:
+			r = r100_cs_packet_parse_vline(p);
+			if (r) {
+				DRM_ERROR("No reloc for ib[%d]=0x%04X\n",
+						idx, reg);
+				r100_cs_dump_packet(p, pkt);
+				return r;
+			}
+			break;
 		/* FIXME: only allow PACKET3 blit? easier to check for out of
 		 * range access */
 		case RADEON_DST_PITCH_OFFSET: