From 39d0e1dc2812464507bc6e3ad94a104ea5452f4e Mon Sep 17 00:00:00 2001
From: patrick <patrick@openbsd.org>
Date: Mon, 18 Jul 2016 11:53:32 +0000
Subject: [PATCH] Some SoCs have a ranges property set in their device trees. 
 This can be used to translate one memory address to another.  Currently we
 just pass the child's memory address to bus space map.  If one of the parent
 busses implements a ranges property, the child's address property is not the
 real address.  This change hooks up a bus space map function that is aware of
 the ranges property and translates the addresses if needed.

ok kettenis@
looks fine jsg@
---
 sys/arch/arm/simplebus/simplebus.c | 77 +++++++++++++++++++++++++++++-
 1 file changed, 75 insertions(+), 2 deletions(-)

diff --git a/sys/arch/arm/simplebus/simplebus.c b/sys/arch/arm/simplebus/simplebus.c
index 65689d8a859..c818814b62a 100644
--- a/sys/arch/arm/simplebus/simplebus.c
+++ b/sys/arch/arm/simplebus/simplebus.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: simplebus.c,v 1.6 2016/07/13 20:42:44 patrick Exp $ */
+/* $OpenBSD: simplebus.c,v 1.7 2016/07/18 11:53:32 patrick Exp $ */
 /*
  * Copyright (c) 2016 Patrick Wildt <patrick@blueri.se>
  *
@@ -29,6 +29,7 @@ int simplebus_match(struct device *, void *, void *);
 void simplebus_attach(struct device *, struct device *, void *);
 
 void simplebus_attach_node(struct device *, int);
+int simplebus_bs_map(void *, bus_addr_t, bus_size_t, int, bus_space_handle_t *);
 
 struct simplebus_softc {
 	struct device		 sc_dev;
@@ -37,6 +38,11 @@ struct simplebus_softc {
 	bus_dma_tag_t		 sc_dmat;
 	int			 sc_acells;
 	int			 sc_scells;
+	int			 sc_pacells;
+	int			 sc_pscells;
+	struct bus_space	 sc_bus;
+	int			*sc_ranges;
+	int			 sc_rangeslen;
 };
 
 struct cfattach simplebus_ca = {
@@ -80,6 +86,8 @@ simplebus_attach(struct device *parent, struct device *self, void *aux)
 	    fa->fa_acells);
 	sc->sc_scells = OF_getpropint(sc->sc_node, "#size-cells",
 	    fa->fa_scells);
+	sc->sc_pacells = fa->fa_acells;
+	sc->sc_pscells = fa->fa_scells;
 
 	if (OF_getprop(sc->sc_node, "name", name, sizeof(name)) > 0) {
 		name[sizeof(name) - 1] = 0;
@@ -88,6 +96,17 @@ simplebus_attach(struct device *parent, struct device *self, void *aux)
 
 	printf("\n");
 
+	memcpy(&sc->sc_bus, sc->sc_iot, sizeof(sc->sc_bus));
+	sc->sc_bus.bs_cookie = sc;
+	sc->sc_bus.bs_map = simplebus_bs_map;
+
+	sc->sc_rangeslen = OF_getproplen(sc->sc_node, "ranges");
+	if (sc->sc_rangeslen > 0 && !(sc->sc_rangeslen % sizeof(uint32_t))) {
+		sc->sc_ranges = malloc(sc->sc_rangeslen, M_TEMP, M_WAITOK);
+		OF_getpropintarray(sc->sc_node, "ranges", sc->sc_ranges,
+		    sc->sc_rangeslen);
+	}
+
 	/* Scan the whole tree. */
 	for (node = OF_child(sc->sc_node);
 	    node != 0;
@@ -118,7 +137,7 @@ simplebus_attach_node(struct device *self, int node)
 	memset(&fa, 0, sizeof(fa));
 	fa.fa_name = "";
 	fa.fa_node = node;
-	fa.fa_iot = sc->sc_iot;
+	fa.fa_iot = &sc->sc_bus;
 	fa.fa_dmat = sc->sc_dmat;
 	fa.fa_acells = sc->sc_acells;
 	fa.fa_scells = sc->sc_scells;
@@ -146,3 +165,57 @@ simplebus_attach_node(struct device *self, int node)
 	free(fa.fa_reg, M_DEVBUF, fa.fa_nreg * sizeof(uint32_t));
 	free(fa.fa_intr, M_DEVBUF, fa.fa_nintr * sizeof(uint32_t));
 }
+
+/*
+ * Translate memory address if needed.
+ */
+int
+simplebus_bs_map(void *t, bus_addr_t bpa, bus_size_t size,
+    int flag, bus_space_handle_t *bshp)
+{
+	struct simplebus_softc *sc = (struct simplebus_softc *)t;
+	uint64_t addr, rfrom, rto, rsize;
+	uint32_t *range;
+	int parent, rlen, rone;
+
+	addr = bpa;
+	parent = OF_parent(sc->sc_node);
+	if (parent == 0)
+		return bus_space_map(sc->sc_iot, addr, size, flag, bshp);
+
+	if (sc->sc_rangeslen < 0)
+		return EINVAL;
+	if (sc->sc_rangeslen == 0)
+		return bus_space_map(sc->sc_iot, addr, size, flag, bshp);
+
+	rlen = sc->sc_rangeslen / sizeof(uint32_t);
+	rone = sc->sc_pacells + sc->sc_acells + sc->sc_scells;
+
+	/* For each range. */
+	for (range = sc->sc_ranges; rlen >= rone; rlen -= rone, range += rone) {
+		/* Extract from and size, so we can see if we fit. */
+		rfrom = range[0];
+		if (sc->sc_acells == 2)
+			rfrom = (rfrom << 32) + range[1];
+		rsize = range[sc->sc_acells + sc->sc_pacells];
+		if (sc->sc_scells == 2)
+			rsize = (rsize << 32) +
+			    range[sc->sc_acells + sc->sc_pacells + 1];
+
+		/* Try next, if we're not in the range. */
+		if (addr < rfrom || (addr + size) > (rfrom + rsize))
+			continue;
+
+		/* All good, extract to address and translate. */
+		rto = range[sc->sc_acells];
+		if (sc->sc_pacells == 2)
+			rto = (rto << 32) + range[sc->sc_acells + 1];
+
+		addr -= rfrom;
+		addr += rto;
+
+		return bus_space_map(sc->sc_iot, addr, size, flag, bshp);
+	}
+
+	return ESRCH;
+}
-- 
2.20.1