[PATCH v3 1/2] remoteproc: qcom_q6v5_mss: Don't reassign mpss region on shutdown

[Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>]

Trying to reclaim mpss memory while the mba is not running causes the
system to crash on devices with security fuses blown, so leave it
assigned to the remote on shutdown and recover it on a subsequent boot.

Fixes: 6c5a9dc2481b ("remoteproc: qcom: Make secure world call for mem ownership switch")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---

Changes since v2:
- The assignment of mpss memory back to Linux is rejected in the coredump case
  on production devices, so check the return value of q6v5_xfer_mem_ownership()
  before attempting to memcpy() the data.

 drivers/remoteproc/qcom_q6v5_mss.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/remoteproc/qcom_q6v5_mss.c b/drivers/remoteproc/qcom_q6v5_mss.c
index 471128a2e723..25c03a26bf88 100644
--- a/drivers/remoteproc/qcom_q6v5_mss.c
+++ b/drivers/remoteproc/qcom_q6v5_mss.c
@@ -887,11 +887,6 @@ static void q6v5_mba_reclaim(struct q6v5 *qproc)
 		writel(val, qproc->reg_base + QDSP6SS_PWR_CTL_REG);
 	}
 
-	ret = q6v5_xfer_mem_ownership(qproc, &qproc->mpss_perm,
-				      false, qproc->mpss_phys,
-				      qproc->mpss_size);
-	WARN_ON(ret);
-
 	q6v5_reset_assert(qproc);
 
 	q6v5_clk_disable(qproc->dev, qproc->reset_clks,
@@ -981,6 +976,10 @@ static int q6v5_mpss_load(struct q6v5 *qproc)
 			max_addr = ALIGN(phdr->p_paddr + phdr->p_memsz, SZ_4K);
 	}
 
+	/* Try to reset ownership back to Linux */
+	q6v5_xfer_mem_ownership(qproc, &qproc->mpss_perm, false,
+				qproc->mpss_phys, qproc->mpss_size);
+
 	mpss_reloc = relocate ? min_addr : qproc->mpss_phys;
 	qproc->mpss_reloc = mpss_reloc;
 	/* Load firmware segments */
@@ -1070,8 +1069,16 @@ static void qcom_q6v5_dump_segment(struct rproc *rproc,
 	void *ptr = rproc_da_to_va(rproc, segment->da, segment->size);
 
 	/* Unlock mba before copying segments */
-	if (!qproc->dump_mba_loaded)
+	if (!qproc->dump_mba_loaded) {
 		ret = q6v5_mba_load(qproc);
+		if (!ret) {
+			/* Try to reset ownership back to Linux */
+			ret = q6v5_xfer_mem_ownership(qproc, &qproc->mpss_perm,
+						      false,
+						      qproc->mpss_phys,
+						      qproc->mpss_size);
+		}
+	}
 
 	if (!ptr || ret)
 		memset(dest, 0xff, segment->size);
@@ -1123,10 +1130,6 @@ static int q6v5_start(struct rproc *rproc)
 	return 0;
 
 reclaim_mpss:
-	xfermemop_ret = q6v5_xfer_mem_ownership(qproc, &qproc->mpss_perm,
-						false, qproc->mpss_phys,
-						qproc->mpss_size);
-	WARN_ON(xfermemop_ret);
 	q6v5_mba_reclaim(qproc);
 
 	return ret;
-- 
2.23.0