There are several DART variants; print some more details such that we can

distinguish between them.  Pay attention to the apple,dma-range property
that tells us the desired DVA window.  Add support for a new BUS_DMA_FIXED
that allows use of bus_dmamap_load_raw(9) to map things at a pre-determined
DVA.  This last change is needed for the upcoming Apple KMS driver.
Hopefully that is the only driver that will need this, so don't attempt to
turn this into an MI feature.

ok patrick@

2 files changed, 113 insertions, 46 deletions

diff --git a/sys/arch/arm64/dev/apldart.c b/sys/arch/arm64/dev/apldart.c
index 66c2da7b5d9..3d285ec6cef 100644
--- a/sys/arch/arm64/dev/apldart.c
+++ b/sys/arch/arm64/dev/apldart.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: apldart.c,v 1.19 2023/12/23 18:28:38 kettenis Exp $	*/
+/*	$OpenBSD: apldart.c,v 1.20 2024/01/20 11:22:46 kettenis Exp $	*/
 /*
  * Copyright (c) 2021 Mark Kettenis <kettenis@openbsd.org>
  *
@@ -61,6 +61,10 @@
 #define DART_T8020_TTBR_BASE		0x0200
 #define  DART_T8020_TTBR_VALID			(1U << 31)
 
+#define DART_T8110_PARAMS3		0x0008
+#define  DART_T8110_PARAMS3_REV_MIN(x)		(((x) >> 0) & 0xff)
+#define  DART_T8110_PARAMS3_REV_MAJ(x)		(((x) >> 8) & 0xff)
+#define  DART_T8110_PARAMS3_VA_WIDTH(x)		(((x) >> 16) & 0x3f)
 #define DART_T8110_PARAMS4		0x000c
 #define  DART_T8110_PARAMS4_NSID_MASK		(0x1ff << 0)
 #define DART_T8110_TLB_CMD		0x0080
@@ -155,6 +159,7 @@ struct apldart_softc {
 	bus_dma_tag_t		sc_dmat;
 	int			sc_node;
 
+	int			sc_ias;
 	int			sc_nsid;
 	int			sc_nttbr;
 	int			sc_shift;
@@ -168,6 +173,7 @@ struct apldart_softc {
 
 	bus_addr_t		sc_dvabase;
 	bus_addr_t		sc_dvaend;
+	bus_addr_t		sc_dvamask;
 
 	struct apldart_stream	**sc_as;
 	struct iommu_device	sc_id;
@@ -219,7 +225,7 @@ int	apldart_t8110_intr(void *);
 
 void	apldart_t8020_flush_tlb(struct apldart_softc *, int);
 void	apldart_t8110_flush_tlb(struct apldart_softc *, int);
-int	apldart_load_map(struct apldart_stream *, bus_dmamap_t);
+int	apldart_load_map(struct apldart_stream *, bus_dmamap_t, int);
 void	apldart_unload_map(struct apldart_stream *, bus_dmamap_t);
 
 int	apldart_dmamap_create(bus_dma_tag_t, bus_size_t, int, bus_size_t,
@@ -252,7 +258,8 @@ apldart_attach(struct device *parent, struct device *self, void *aux)
 {
 	struct apldart_softc *sc = (struct apldart_softc *)self;
 	struct fdt_attach_args *faa = aux;
-	uint32_t config, params2, params4, tcr, ttbr;
+	uint64_t dva_range[2];
+	uint32_t config, maj, min, params2, params3, params4, tcr, ttbr;
 	int sid, idx;
 
 	if (faa->fa_nreg < 1) {
@@ -273,7 +280,9 @@ apldart_attach(struct device *parent, struct device *self, void *aux)
 	power_domain_enable(sc->sc_node);
 
 	if (OF_is_compatible(sc->sc_node, "apple,t8110-dart")) {
+		params3 = HREAD4(sc, DART_T8110_PARAMS3);
 		params4 = HREAD4(sc, DART_T8110_PARAMS4);
+		sc->sc_ias = DART_T8110_PARAMS3_VA_WIDTH(params3);
 		sc->sc_nsid = params4 & DART_T8110_PARAMS4_NSID_MASK;
 		sc->sc_nttbr = 1;
 		sc->sc_sid_enable_base = DART_T8110_SID_ENABLE_BASE;
@@ -284,7 +293,10 @@ apldart_attach(struct device *parent, struct device *self, void *aux)
 		sc->sc_ttbr_base = DART_T8110_TTBR_BASE;
 		sc->sc_ttbr_valid = DART_T8110_TTBR_VALID;
 		sc->sc_flush_tlb = apldart_t8110_flush_tlb;
+		maj = DART_T8110_PARAMS3_REV_MAJ(params3);
+		min = DART_T8110_PARAMS3_REV_MIN(params3);
 	} else {
+		sc->sc_ias = 32;
 		sc->sc_nsid = 16;
 		sc->sc_nttbr = 4;
 		sc->sc_sid_enable_base = DART_T8020_SID_ENABLE;
@@ -295,6 +307,7 @@ apldart_attach(struct device *parent, struct device *self, void *aux)
 		sc->sc_ttbr_base = DART_T8020_TTBR_BASE;
 		sc->sc_ttbr_valid = DART_T8020_TTBR_VALID;
 		sc->sc_flush_tlb = apldart_t8020_flush_tlb;
+		maj = min = 0;
 	}
 
 	if (OF_is_compatible(sc->sc_node, "apple,t6000-dart") ||
@@ -312,6 +325,19 @@ apldart_attach(struct device *parent, struct device *self, void *aux)
 			sc->sc_locked = 1;
 	}
 
+	if (maj != 0 || min != 0)
+		printf(" rev %d.%d", maj, min);
+
+	printf(": %d bits", sc->sc_ias);
+
+	/*
+	 * Anything over 36 bits requires 4-level page tables which we
+	 * don't implement yet.  So limit to 36 bits.
+	 */
+	if (sc->sc_ias > 36)
+		sc->sc_ias = 36;
+	sc->sc_dvamask = (1ULL << sc->sc_ias) - 1;
+
 	/*
 	 * Resetting the DART used for the display controller will
 	 * kill the framebuffer.  This should be the only DART that
@@ -346,25 +372,33 @@ apldart_attach(struct device *parent, struct device *self, void *aux)
 	    !sc->sc_locked && !sc->sc_translating) {
 		for (sid = 0; sid < sc->sc_nsid; sid++)
 			HWRITE4(sc, DART_TCR(sc, sid), sc->sc_tcr_bypass);
-		printf(": bypass\n");
+		printf(", bypass\n");
 		return;
 	}
 
 	if (sc->sc_locked)
-		printf(": locked\n");
+		printf(", locked\n");
 	else if (sc->sc_translating)
-		printf(": translating\n");
+		printf(", translating\n");
 	else
 		printf("\n");
 
-	/*
-	 * Skip the first page to help catching bugs where a device is
-	 * doing DMA to/from address zero because we didn't properly
-	 * set up the DMA transfer.  Skip the last page to avoid using
-	 * the address reserved for MSIs.
-	 */
-	sc->sc_dvabase = DART_PAGE_SIZE;
-	sc->sc_dvaend = 0xffffffff - DART_PAGE_SIZE;
+	if (OF_getpropint64array(sc->sc_node, "apple,dma-range",
+	    dva_range, sizeof(dva_range)) == sizeof(dva_range)) {
+		sc->sc_dvabase = dva_range[0];
+		sc->sc_dvaend = dva_range[0] + dva_range[1] - 1;
+	} else {
+		/*
+		 * Restrict ourselves to 32-bit addresses to cater for
+		 * devices that don't do 64-bit DMA.  Skip the first
+		 * page to help catching bugs where a device is doing
+		 * DMA to/from address zero because we didn't properly
+		 * set up the DMA transfer.  Skip the last page to
+		 * avoid using the address reserved for MSIs.
+		 */
+		sc->sc_dvabase = DART_PAGE_SIZE;
+		sc->sc_dvaend = 0xffffffff - DART_PAGE_SIZE;
+	}
 
 	if (!sc->sc_locked && !sc->sc_translating) {
 		/* Disable translations. */
@@ -430,7 +464,7 @@ apldart_resume(struct apldart_softc *sc)
 		return;
 	}
 
-	ntte = howmany(sc->sc_dvaend, DART_PAGE_SIZE);
+	ntte = howmany((sc->sc_dvaend & sc->sc_dvamask), DART_PAGE_SIZE);
 	nl2 = howmany(ntte, DART_PAGE_SIZE / sizeof(uint64_t));
 	nl1 = howmany(nl2, DART_PAGE_SIZE / sizeof(uint64_t));
 
@@ -495,7 +529,7 @@ apldart_init_locked_stream(struct apldart_stream *as)
 	uint32_t ttbr;
 	vaddr_t startva, endva, va;
 	paddr_t pa;
-	bus_addr_t dva, dvaend;
+	bus_addr_t dva, dvaend, dvabase;
 	volatile uint64_t *l1;
 	int nl1, nl2, ntte;
 	int idx;
@@ -510,15 +544,23 @@ apldart_init_locked_stream(struct apldart_stream *as)
 	nl2 = idx * (DART_PAGE_SIZE / sizeof(uint64_t));
 	ntte = nl2 * (DART_PAGE_SIZE / sizeof(uint64_t));
 
-	dvaend = (bus_addr_t)ntte * DART_PAGE_SIZE;
+	dvabase = sc->sc_dvabase & ~sc->sc_dvamask;
+	dvaend = dvabase + (bus_addr_t)ntte * DART_PAGE_SIZE;
 	if (dvaend < sc->sc_dvaend)
 		sc->sc_dvaend = dvaend;
 
-	as->as_dvamap = extent_create(sc->sc_dev.dv_xname,
-	    sc->sc_dvabase, sc->sc_dvaend, M_DEVBUF,
-	    NULL, 0, EX_WAITOK | EX_NOCOALESCE);
+	as->as_dvamap = extent_create(sc->sc_dev.dv_xname, 0, ULONG_MAX,
+	    M_DEVBUF, NULL, 0, EX_WAITOK | EX_NOCOALESCE);
+	if (sc->sc_dvabase > 0) {
+		extent_alloc_region(as->as_dvamap, 0, sc->sc_dvabase,
+		    EX_WAITOK);
+	}
+	if (sc->sc_dvaend < ULONG_MAX) {
+		extent_alloc_region(as->as_dvamap, sc->sc_dvaend + 1,
+		    ULONG_MAX - sc->sc_dvaend, EX_WAITOK);
+	}
 
-	ntte = howmany(sc->sc_dvaend, DART_PAGE_SIZE);
+	ntte = howmany((sc->sc_dvaend & sc->sc_dvamask), DART_PAGE_SIZE);
 	nl2 = howmany(ntte, DART_PAGE_SIZE / sizeof(uint64_t));
 	nl1 = howmany(nl2, DART_PAGE_SIZE / sizeof(uint64_t));
 
@@ -545,12 +587,8 @@ apldart_init_locked_stream(struct apldart_stream *as)
 			dva = idx * (DART_PAGE_SIZE / sizeof(uint64_t)) *
 			    DART_PAGE_SIZE;
 			dvaend = dva + DART_PAGE_SIZE * DART_PAGE_SIZE - 1;
-			if (dva < sc->sc_dvabase)
-				dva = sc->sc_dvabase;
-			if (dvaend > sc->sc_dvaend)
-				dvaend = sc->sc_dvaend;
-			extent_alloc_region(as->as_dvamap, dva,
-			    dvaend - dva + 1, EX_CONFLICTOK);
+			extent_alloc_region(as->as_dvamap, dvabase + dva,
+			    dvaend - dva + 1, EX_WAITOK | EX_CONFLICTOK);
 		} else {
 			as->as_l2[idx] = apldart_dmamem_alloc(sc->sc_dmat,
 			    DART_PAGE_SIZE, DART_PAGE_SIZE);
@@ -593,9 +631,16 @@ apldart_alloc_stream(struct apldart_softc *sc, int sid)
 		return as;
 	}
 
-	as->as_dvamap = extent_create(sc->sc_dev.dv_xname,
-	    sc->sc_dvabase, sc->sc_dvaend, M_DEVBUF,
-	    NULL, 0, EX_WAITOK | EX_NOCOALESCE);
+	as->as_dvamap = extent_create(sc->sc_dev.dv_xname, 0, ULONG_MAX,
+	    M_DEVBUF, NULL, 0, EX_WAITOK | EX_NOCOALESCE);
+	if (sc->sc_dvabase > 0) {
+		extent_alloc_region(as->as_dvamap, 0, sc->sc_dvabase,
+		    EX_WAITOK);
+	}
+	if (sc->sc_dvaend < ULONG_MAX) {
+		extent_alloc_region(as->as_dvamap, sc->sc_dvaend + 1,
+		    ULONG_MAX - sc->sc_dvaend, EX_WAITOK);
+	}
 
 	/*
 	 * Build translation tables.  We pre-allocate the translation
@@ -603,7 +648,7 @@ apldart_alloc_stream(struct apldart_softc *sc, int sid)
 	 * worry about growing them in an mpsafe manner later.
 	 */
 
-	ntte = howmany(sc->sc_dvaend, DART_PAGE_SIZE);
+	ntte = howmany((sc->sc_dvaend & sc->sc_dvamask), DART_PAGE_SIZE);
 	nl2 = howmany(ntte, DART_PAGE_SIZE / sizeof(uint64_t));
 	nl1 = howmany(nl2, DART_PAGE_SIZE / sizeof(uint64_t));
 
@@ -730,7 +775,7 @@ apldart_t8110_flush_tlb(struct apldart_softc *sc, int sid)
 volatile uint64_t *
 apldart_lookup_tte(struct apldart_stream *as, bus_addr_t dva)
 {
-	int idx = dva / DART_PAGE_SIZE;
+	int idx = (dva & as->as_sc->sc_dvamask) / DART_PAGE_SIZE;
 	int l2_idx = idx / (DART_PAGE_SIZE / sizeof(uint64_t));
 	int tte_idx = idx % (DART_PAGE_SIZE / sizeof(uint64_t));
 	volatile uint64_t *l2;
@@ -740,7 +785,7 @@ apldart_lookup_tte(struct apldart_stream *as, bus_addr_t dva)
 }
 
 int
-apldart_load_map(struct apldart_stream *as, bus_dmamap_t map)
+apldart_load_map(struct apldart_stream *as, bus_dmamap_t map, int flags)
 {
 	struct apldart_softc *sc = as->as_sc;
 	struct apldart_map_state *ams = map->_dm_cookie;
@@ -757,8 +802,18 @@ apldart_load_map(struct apldart_stream *as, bus_dmamap_t map)
 		len = apldart_round_page(map->dm_segs[seg].ds_len + off);
 
 		mtx_enter(&as->as_dvamap_mtx);
-		error = extent_alloc_with_descr(as->as_dvamap, len,
-		    DART_PAGE_SIZE, 0, 0, EX_NOWAIT, &ams[seg].ams_er, &dva);
+		if (flags & BUS_DMA_FIXED) {
+			dva = apldart_trunc_page(map->dm_segs[seg].ds_addr);
+			/* XXX truncate because "apple,dma-range" mismatch */
+			if (dva > sc->sc_dvaend)
+				dva &= sc->sc_dvamask;
+			error = extent_alloc_region_with_descr(as->as_dvamap,
+			    dva, len, EX_NOWAIT, &ams[seg].ams_er);
+		} else {
+			error = extent_alloc_with_descr(as->as_dvamap, len,
+			    DART_PAGE_SIZE, 0, 0, EX_NOWAIT, &ams[seg].ams_er,
+			    &dva);
+		}
 		mtx_leave(&as->as_dvamap_mtx);
 		if (error) {
 			apldart_unload_map(as, map);
@@ -887,7 +942,7 @@ apldart_dmamap_load(bus_dma_tag_t t, bus_dmamap_t map, void *buf,
 	if (error)
 		return error;
 
-	error = apldart_load_map(as, map);
+	error = apldart_load_map(as, map, flags);
 	if (error)
 		sc->sc_dmat->_dmamap_unload(sc->sc_dmat, map);
 
@@ -907,7 +962,7 @@ apldart_dmamap_load_mbuf(bus_dma_tag_t t, bus_dmamap_t map,
 	if (error)
 		return error;
 
-	error = apldart_load_map(as, map);
+	error = apldart_load_map(as, map, flags);
 	if (error)
 		sc->sc_dmat->_dmamap_unload(sc->sc_dmat, map);
 
@@ -927,7 +982,7 @@ apldart_dmamap_load_uio(bus_dma_tag_t t, bus_dmamap_t map,
 	if (error)
 		return error;
 
-	error = apldart_load_map(as, map);
+	error = apldart_load_map(as, map, flags);
 	if (error)
 		sc->sc_dmat->_dmamap_unload(sc->sc_dmat, map);
 
@@ -940,14 +995,25 @@ apldart_dmamap_load_raw(bus_dma_tag_t t, bus_dmamap_t map,
 {
 	struct apldart_stream *as = t->_cookie;
 	struct apldart_softc *sc = as->as_sc;
-	int error;
-
-	error = sc->sc_dmat->_dmamap_load_raw(sc->sc_dmat, map,
-	     segs, nsegs, size, flags);
-	if (error)
-		return error;
+	int i, error;
+
+	if (flags & BUS_DMA_FIXED) {
+		if (map->dm_nsegs != nsegs)
+			return EINVAL;
+		for (i = 0; i < nsegs; i++) {
+			if (map->dm_segs[i].ds_len != segs[i].ds_len)
+				return EINVAL;
+			map->dm_segs[i]._ds_paddr = segs[i].ds_addr;
+			map->dm_segs[i]._ds_vaddr = segs[i]._ds_vaddr;
+		}
+	} else {
+		error = sc->sc_dmat->_dmamap_load_raw(sc->sc_dmat, map,
+		     segs, nsegs, size, flags);
+		if (error)
+			return error;
+	}
 
-	error = apldart_load_map(as, map);
+	error = apldart_load_map(as, map, flags);
 	if (error)
 		sc->sc_dmat->_dmamap_unload(sc->sc_dmat, map);
 
diff --git a/sys/arch/arm64/include/bus.h b/sys/arch/arm64/include/bus.h
index 49b5e42a7b0..84464eb45aa 100644
--- a/sys/arch/arm64/include/bus.h
+++ b/sys/arch/arm64/include/bus.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: bus.h,v 1.9 2023/01/21 10:30:11 kettenis Exp $ */
+/* $OpenBSD: bus.h,v 1.10 2024/01/20 11:22:46 kettenis Exp $ */
 /*
  * Copyright (c) 2003-2004 Opsycon AB Sweden.  All rights reserved.
  *
@@ -335,6 +335,7 @@ bus_space_barrier(bus_space_tag_t t, bus_space_handle_t h, bus_size_t offset,
 #define	BUS_DMA_ZERO		0x0800	/* zero memory in dmamem_alloc */
 #define	BUS_DMA_NOCACHE		0x1000
 #define	BUS_DMA_64BIT		0x2000	/* device handles 64bit dva */
+#define	BUS_DMA_FIXED		0x4000	/* place mapping at specified dva */
 
 /* Forwards needed by prototypes below. */
 struct mbuf;