From: kettenis <kettenis@openbsd.org>
Date: Mon, 28 Feb 2022 15:51:02 +0000 (+0000)
Subject: The IOMMUs integrated on Apple's M1 Pro/MaxJ SoC use a different page table
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=5d50335578fc88e884390db4ed94a97c7ff0360a;p=openbsd

The IOMMUs integrated on Apple's M1 Pro/MaxJ SoC use a different page table
layout where the physical (CPU) address needs to be shifted to allow for the
larger physical address space implemented in these SoCs.  Make apldart(4)
handle this new page table layout based on the compatible property.

ok jsg@
---

diff --git a/sys/arch/arm64/dev/apldart.c b/sys/arch/arm64/dev/apldart.c
index 6eaafdbeb42..949517cb397 100644
--- a/sys/arch/arm64/dev/apldart.c
+++ b/sys/arch/arm64/dev/apldart.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: apldart.c,v 1.10 2022/02/27 17:36:52 kettenis Exp $	*/
+/*	$OpenBSD: apldart.c,v 1.11 2022/02/28 15:51:02 kettenis Exp $	*/
 /*
  * Copyright (c) 2021 Mark Kettenis <kettenis@openbsd.org>
  *
@@ -117,6 +117,7 @@ struct apldart_softc {
 	struct extent		*sc_dvamap;
 	struct mutex		sc_dvamap_mtx;
 
+	int			sc_shift;
 	struct apldart_dmamem	*sc_l1;
 	struct apldart_dmamem	**sc_l2;
 
@@ -185,7 +186,8 @@ apldart_match(struct device *parent, void *match, void *aux)
 {
 	struct fdt_attach_args *faa = aux;
 
-	return OF_is_compatible(faa->fa_node, "apple,t8103-dart");
+	return OF_is_compatible(faa->fa_node, "apple,t8103-dart") ||
+	    OF_is_compatible(faa->fa_node, "apple,t6000-dart");
 }
 
 void
@@ -238,6 +240,9 @@ apldart_attach(struct device *parent, struct device *self, void *aux)
 
 	printf("\n");
 
+	if (OF_is_compatible(faa->fa_node, "apple,t6000-dart"))
+		sc->sc_shift = 4;
+
 	/*
 	 * Skip the first page to help catching bugs where a device is
 	 * doing DMA to/from address zero because we didn't properly
@@ -277,7 +282,8 @@ apldart_attach(struct device *parent, struct device *self, void *aux)
 	for (idx = 0; idx < nl2; idx++) {
 		sc->sc_l2[idx] = apldart_dmamem_alloc(sc->sc_dmat,
 		    DART_PAGE_SIZE, DART_PAGE_SIZE);
-		l1[idx] = APLDART_DMA_DVA(sc->sc_l2[idx]) | DART_L1_TABLE;
+		pa = APLDART_DMA_DVA(sc->sc_l2[idx]);
+		l1[idx] = (pa >> sc->sc_shift) | DART_L1_TABLE;
 	}
 
 	/* Install page tables. */
@@ -405,7 +411,7 @@ apldart_load_map(struct apldart_softc *sc, bus_dmamap_t map)
 				end = apldart_round_offset(len) - 1;
 
 			tte = apldart_lookup_tte(sc, dva);
-			*tte = pa | DART_L2_VALID |
+			*tte = (pa >> sc->sc_shift) | DART_L2_VALID |
 			    DART_L2_START(start) | DART_L2_END(end);
 
 			pa += DART_PAGE_SIZE;