remoteproc: qcom_q6v5: Assign mpss region to Q6 before MBA boot

On secure devices which support warm reset, the MBA firmware requires
access to the modem region to clear them out. Hence provide Q6 access
to this region before MBA boot. This will be a nop during a modem SSR.
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
Link: https://lore.kernel.org/r/20200917175840.18708-1-sibis@codeaurora.orgSigned-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/remoteproc/qcom_q6v5_mss.c

@@ -931,6 +931,17 @@ static int q6v5_mba_load(struct q6v5 *qproc)
 		goto assert_reset;
 	}
 
+	/*
+	 * Some versions of the MBA firmware will upon boot wipe the MPSS region as well, so provide
+	 * the Q6 access to this region.
+	 */
+	ret = q6v5_xfer_mem_ownership(qproc, &qproc->mpss_perm, false, true,
+				      qproc->mpss_phys, qproc->mpss_size);
+	if (ret) {
+		dev_err(qproc->dev, "assigning Q6 access to mpss memory failed: %d\n", ret);
+		goto disable_active_clks;
+	}
+
 	/* Assign MBA image access in DDR to q6 */
 	ret = q6v5_xfer_mem_ownership(qproc, &qproc->mba_perm, false, true,
 				      qproc->mba_phys, qproc->mba_size);
@@ -1135,10 +1146,9 @@ static int q6v5_mpss_load(struct q6v5 *qproc)
 			max_addr = ALIGN(phdr->p_paddr + phdr->p_memsz, SZ_4K);
 	}
 
-	/**
+	/*
 	 * In case of a modem subsystem restart on secure devices, the modem
-	 * memory can be reclaimed only after MBA is loaded. For modem cold
-	 * boot this will be a nop
+	 * memory can be reclaimed only after MBA is loaded.
 	 */
 	q6v5_xfer_mem_ownership(qproc, &qproc->mpss_perm, true, false,
 				qproc->mpss_phys, qproc->mpss_size);