1/*-
2 * Copyright (c) 2013, Nathan Whitehorn <nwhitehorn@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice unmodified, this list of conditions, and the following
10 *    disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#include <sys/param.h>
31#include <sys/bus.h>
32#include <sys/kernel.h>
33#include <sys/libkern.h>
34#include <sys/module.h>
35#include <sys/vmem.h>
36
37#include <dev/ofw/ofw_bus.h>
38#include <dev/ofw/ofw_bus_subr.h>
39#include <dev/ofw/openfirm.h>
40
41#include <machine/bus.h>
42
43#include <powerpc/pseries/phyp-hvcall.h>
44#include <powerpc/pseries/plpar_iommu.h>
45
46MALLOC_DEFINE(M_PHYPIOMMU, "iommu", "IOMMU data for PAPR LPARs");
47
48struct papr_iommu_map {
49	uint32_t iobn;
50	vmem_t *vmem;
51	struct papr_iommu_map *next;
52};
53
54static SLIST_HEAD(iommu_maps, iommu_map) iommu_map_head =
55    SLIST_HEAD_INITIALIZER(iommu_map_head);
56static int papr_supports_stuff_tce = -1;
57
58struct iommu_map {
59	uint32_t iobn;
60	vmem_t *vmem;
61
62	SLIST_ENTRY(iommu_map) entries;
63};
64
65struct dma_window {
66	struct iommu_map *map;
67	bus_addr_t start;
68	bus_addr_t end;
69};
70
71int
72phyp_iommu_set_dma_tag(device_t bus, device_t dev, bus_dma_tag_t tag)
73{
74	device_t p;
75	phandle_t node;
76	cell_t dma_acells, dma_scells, dmawindow[6];
77	struct iommu_map *i;
78	int cell;
79
80	for (p = dev; device_get_parent(p) != NULL; p = device_get_parent(p)) {
81		if (ofw_bus_has_prop(p, "ibm,my-dma-window"))
82			break;
83		if (ofw_bus_has_prop(p, "ibm,dma-window"))
84			break;
85	}
86
87	if (p == NULL)
88		return (ENXIO);
89
90	node = ofw_bus_get_node(p);
91	if (OF_getprop(node, "ibm,#dma-size-cells", &dma_scells,
92	    sizeof(cell_t)) <= 0)
93		OF_searchprop(node, "#size-cells", &dma_scells, sizeof(cell_t));
94	if (OF_getprop(node, "ibm,#dma-address-cells", &dma_acells,
95	    sizeof(cell_t)) <= 0)
96		OF_searchprop(node, "#address-cells", &dma_acells,
97		    sizeof(cell_t));
98
99	if (ofw_bus_has_prop(p, "ibm,my-dma-window"))
100		OF_getprop(node, "ibm,my-dma-window", dmawindow,
101		    sizeof(cell_t)*(dma_scells + dma_acells + 1));
102	else
103		OF_getprop(node, "ibm,dma-window", dmawindow,
104		    sizeof(cell_t)*(dma_scells + dma_acells + 1));
105
106	struct dma_window *window = malloc(sizeof(struct dma_window),
107	    M_PHYPIOMMU, M_WAITOK);
108	window->start = 0;
109	for (cell = 1; cell < 1 + dma_acells; cell++) {
110		window->start <<= 32;
111		window->start |= dmawindow[cell];
112	}
113	window->end = 0;
114	for (; cell < 1 + dma_acells + dma_scells; cell++) {
115		window->end <<= 32;
116		window->end |= dmawindow[cell];
117	}
118	window->end += window->start;
119
120	if (bootverbose)
121		device_printf(dev, "Mapping IOMMU domain %#x\n", dmawindow[0]);
122	window->map = NULL;
123	SLIST_FOREACH(i, &iommu_map_head, entries) {
124		if (i->iobn == dmawindow[0]) {
125			window->map = i;
126			break;
127		}
128	}
129
130	if (window->map == NULL) {
131		window->map = malloc(sizeof(struct iommu_map), M_PHYPIOMMU,
132		    M_WAITOK);
133		window->map->iobn = dmawindow[0];
134		/*
135		 * Allocate IOMMU range beginning at PAGE_SIZE. Some drivers
136		 * (em(4), for example) do not like getting mappings at 0.
137		 */
138		window->map->vmem = vmem_create("IOMMU mappings", PAGE_SIZE,
139		    trunc_page(VMEM_ADDR_MAX) - PAGE_SIZE, PAGE_SIZE, 0,
140		    M_BESTFIT | M_NOWAIT);
141		SLIST_INSERT_HEAD(&iommu_map_head, window->map, entries);
142	}
143
144	/*
145	 * Check experimentally whether we can use H_STUFF_TCE. It is required
146	 * by the spec but some firmware (e.g. QEMU) does not actually support
147	 * it
148	 */
149	if (papr_supports_stuff_tce == -1)
150		papr_supports_stuff_tce = !(phyp_hcall(H_STUFF_TCE,
151		    window->map->iobn, 0, 0, 0) == H_FUNCTION);
152
153	bus_dma_tag_set_iommu(tag, bus, window);
154
155	return (0);
156}
157
158int
159phyp_iommu_map(device_t dev, bus_dma_segment_t *segs, int *nsegs,
160    bus_addr_t min, bus_addr_t max, bus_size_t alignment, bus_addr_t boundary,
161    void *cookie)
162{
163	struct dma_window *window = cookie;
164	bus_addr_t minaddr, maxaddr;
165	bus_addr_t alloced;
166	bus_size_t allocsize;
167	int error, i, j;
168	uint64_t tce;
169	minaddr = window->start;
170	maxaddr = window->end;
171
172	/* XXX: handle exclusion range in a more useful way */
173	if (min < maxaddr)
174		maxaddr = min;
175
176	/* XXX: consolidate segs? */
177	for (i = 0; i < *nsegs; i++) {
178		allocsize = round_page(segs[i].ds_len +
179		    (segs[i].ds_addr & PAGE_MASK));
180		error = vmem_xalloc(window->map->vmem, allocsize,
181		    (alignment < PAGE_SIZE) ? PAGE_SIZE : alignment, 0,
182		    boundary, minaddr, maxaddr, M_BESTFIT | M_NOWAIT, &alloced);
183		if (error != 0) {
184			panic("VMEM failure: %d\n", error);
185			return (error);
186		}
187		KASSERT(alloced % PAGE_SIZE == 0, ("Alloc not page aligned"));
188		KASSERT((alloced + (segs[i].ds_addr & PAGE_MASK)) %
189		    alignment == 0,
190		    ("Allocated segment does not match alignment constraint"));
191
192		tce = trunc_page(segs[i].ds_addr);
193		tce |= 0x3; /* read/write */
194		for (j = 0; j < allocsize; j += PAGE_SIZE) {
195			error = phyp_hcall(H_PUT_TCE, window->map->iobn,
196			    alloced + j, tce + j);
197			if (error < 0) {
198				panic("IOMMU mapping error: %d\n", error);
199				return (ENOMEM);
200			}
201		}
202
203		segs[i].ds_addr = alloced + (segs[i].ds_addr & PAGE_MASK);
204		KASSERT(segs[i].ds_addr > 0, ("Address needs to be positive"));
205		KASSERT(segs[i].ds_addr + segs[i].ds_len < maxaddr,
206		    ("Address not in range"));
207		if (error < 0) {
208			panic("IOMMU mapping error: %d\n", error);
209			return (ENOMEM);
210		}
211	}
212
213	return (0);
214}
215
216int
217phyp_iommu_unmap(device_t dev, bus_dma_segment_t *segs, int nsegs, void *cookie)
218{
219	struct dma_window *window = cookie;
220	bus_addr_t pageround;
221	bus_size_t roundedsize;
222	int i;
223	bus_addr_t j;
224
225	for (i = 0; i < nsegs; i++) {
226		pageround = trunc_page(segs[i].ds_addr);
227		roundedsize = round_page(segs[i].ds_len +
228		    (segs[i].ds_addr & PAGE_MASK));
229
230		if (papr_supports_stuff_tce) {
231			phyp_hcall(H_STUFF_TCE, window->map->iobn, pageround, 0,
232			    roundedsize/PAGE_SIZE);
233		} else {
234			for (j = 0; j < roundedsize; j += PAGE_SIZE)
235				phyp_hcall(H_PUT_TCE, window->map->iobn,
236				    pageround + j, 0);
237		}
238
239		vmem_xfree(window->map->vmem, pageround, roundedsize);
240	}
241
242	return (0);
243}
244
245