xref: /freebsd/sys/powerpc/pseries/plpar_iommu.c (revision cab6a39d7b343596a5823e65c0f7b426551ec22d)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2013, Nathan Whitehorn <nwhitehorn@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/bus.h>
34 #include <sys/kernel.h>
35 #include <sys/libkern.h>
36 #include <sys/module.h>
37 #include <sys/vmem.h>
38 
39 #include <dev/ofw/ofw_bus.h>
40 #include <dev/ofw/ofw_bus_subr.h>
41 #include <dev/ofw/openfirm.h>
42 
43 #include <machine/bus.h>
44 
45 #include <powerpc/pseries/phyp-hvcall.h>
46 #include <powerpc/pseries/plpar_iommu.h>
47 
48 MALLOC_DEFINE(M_PHYPIOMMU, "iommu", "IOMMU data for PAPR LPARs");
49 
50 struct papr_iommu_map {
51 	uint32_t iobn;
52 	vmem_t *vmem;
53 	struct papr_iommu_map *next;
54 };
55 
56 static SLIST_HEAD(iommu_maps, iommu_map) iommu_map_head =
57     SLIST_HEAD_INITIALIZER(iommu_map_head);
58 static int papr_supports_stuff_tce = -1;
59 
60 struct iommu_map {
61 	uint32_t iobn;
62 	vmem_t *vmem;
63 
64 	SLIST_ENTRY(iommu_map) entries;
65 };
66 
67 struct dma_window {
68 	struct iommu_map *map;
69 	bus_addr_t start;
70 	bus_addr_t end;
71 };
72 
73 int
74 phyp_iommu_set_dma_tag(device_t bus, device_t dev, bus_dma_tag_t tag)
75 {
76 	device_t p;
77 	phandle_t node;
78 	cell_t dma_acells, dma_scells, dmawindow[6];
79 	struct iommu_map *i;
80 	int cell;
81 
82 	for (p = dev; device_get_parent(p) != NULL; p = device_get_parent(p)) {
83 		if (ofw_bus_has_prop(p, "ibm,my-dma-window"))
84 			break;
85 		if (ofw_bus_has_prop(p, "ibm,dma-window"))
86 			break;
87 	}
88 
89 	if (p == NULL)
90 		return (ENXIO);
91 
92 	node = ofw_bus_get_node(p);
93 	if (OF_getencprop(node, "ibm,#dma-size-cells", &dma_scells,
94 	    sizeof(cell_t)) <= 0)
95 		OF_searchencprop(node, "#size-cells", &dma_scells,
96 		    sizeof(cell_t));
97 	if (OF_getencprop(node, "ibm,#dma-address-cells", &dma_acells,
98 	    sizeof(cell_t)) <= 0)
99 		OF_searchencprop(node, "#address-cells", &dma_acells,
100 		    sizeof(cell_t));
101 
102 	if (ofw_bus_has_prop(p, "ibm,my-dma-window"))
103 		OF_getencprop(node, "ibm,my-dma-window", dmawindow,
104 		    sizeof(cell_t)*(dma_scells + dma_acells + 1));
105 	else
106 		OF_getencprop(node, "ibm,dma-window", dmawindow,
107 		    sizeof(cell_t)*(dma_scells + dma_acells + 1));
108 
109 	struct dma_window *window = malloc(sizeof(struct dma_window),
110 	    M_PHYPIOMMU, M_WAITOK);
111 	window->start = 0;
112 	for (cell = 1; cell < 1 + dma_acells; cell++) {
113 		window->start <<= 32;
114 		window->start |= dmawindow[cell];
115 	}
116 	window->end = 0;
117 	for (; cell < 1 + dma_acells + dma_scells; cell++) {
118 		window->end <<= 32;
119 		window->end |= dmawindow[cell];
120 	}
121 	window->end += window->start;
122 
123 	if (bootverbose)
124 		device_printf(dev, "Mapping IOMMU domain %#x\n", dmawindow[0]);
125 	window->map = NULL;
126 	SLIST_FOREACH(i, &iommu_map_head, entries) {
127 		if (i->iobn == dmawindow[0]) {
128 			window->map = i;
129 			break;
130 		}
131 	}
132 
133 	if (window->map == NULL) {
134 		window->map = malloc(sizeof(struct iommu_map), M_PHYPIOMMU,
135 		    M_WAITOK);
136 		window->map->iobn = dmawindow[0];
137 		/*
138 		 * Allocate IOMMU range beginning at PAGE_SIZE. Some drivers
139 		 * (em(4), for example) do not like getting mappings at 0.
140 		 */
141 		window->map->vmem = vmem_create("IOMMU mappings", PAGE_SIZE,
142 		    trunc_page(VMEM_ADDR_MAX) - PAGE_SIZE, PAGE_SIZE, 0,
143 		    M_BESTFIT | M_NOWAIT);
144 		SLIST_INSERT_HEAD(&iommu_map_head, window->map, entries);
145 	}
146 
147 	/*
148 	 * Check experimentally whether we can use H_STUFF_TCE. It is required
149 	 * by the spec but some firmware (e.g. QEMU) does not actually support
150 	 * it
151 	 */
152 	if (papr_supports_stuff_tce == -1)
153 		papr_supports_stuff_tce = !(phyp_hcall(H_STUFF_TCE,
154 		    window->map->iobn, 0, 0, 0) == H_FUNCTION);
155 
156 	bus_dma_tag_set_iommu(tag, bus, window);
157 
158 	return (0);
159 }
160 
161 int
162 phyp_iommu_map(device_t dev, bus_dma_segment_t *segs, int *nsegs,
163     bus_addr_t min, bus_addr_t max, bus_size_t alignment, bus_addr_t boundary,
164     void *cookie)
165 {
166 	struct dma_window *window = cookie;
167 	bus_addr_t minaddr, maxaddr;
168 	bus_addr_t alloced;
169 	bus_size_t allocsize;
170 	int error, i, j;
171 	uint64_t tce;
172 	minaddr = window->start;
173 	maxaddr = window->end;
174 
175 	/* XXX: handle exclusion range in a more useful way */
176 	if (min < maxaddr)
177 		maxaddr = min;
178 
179 	/* XXX: consolidate segs? */
180 	for (i = 0; i < *nsegs; i++) {
181 		allocsize = round_page(segs[i].ds_len +
182 		    (segs[i].ds_addr & PAGE_MASK));
183 		error = vmem_xalloc(window->map->vmem, allocsize,
184 		    (alignment < PAGE_SIZE) ? PAGE_SIZE : alignment, 0,
185 		    boundary, minaddr, maxaddr, M_BESTFIT | M_NOWAIT, &alloced);
186 		if (error != 0) {
187 			panic("VMEM failure: %d\n", error);
188 			return (error);
189 		}
190 		KASSERT(alloced % PAGE_SIZE == 0, ("Alloc not page aligned"));
191 		KASSERT((alloced + (segs[i].ds_addr & PAGE_MASK)) %
192 		    alignment == 0,
193 		    ("Allocated segment does not match alignment constraint"));
194 
195 		tce = trunc_page(segs[i].ds_addr);
196 		tce |= 0x3; /* read/write */
197 		for (j = 0; j < allocsize; j += PAGE_SIZE) {
198 			error = phyp_hcall(H_PUT_TCE, window->map->iobn,
199 			    alloced + j, tce + j);
200 			if (error < 0) {
201 				panic("IOMMU mapping error: %d\n", error);
202 				return (ENOMEM);
203 			}
204 		}
205 
206 		segs[i].ds_addr = alloced + (segs[i].ds_addr & PAGE_MASK);
207 		KASSERT(segs[i].ds_addr > 0, ("Address needs to be positive"));
208 		KASSERT(segs[i].ds_addr + segs[i].ds_len < maxaddr,
209 		    ("Address not in range"));
210 		if (error < 0) {
211 			panic("IOMMU mapping error: %d\n", error);
212 			return (ENOMEM);
213 		}
214 	}
215 
216 	return (0);
217 }
218 
219 int
220 phyp_iommu_unmap(device_t dev, bus_dma_segment_t *segs, int nsegs, void *cookie)
221 {
222 	struct dma_window *window = cookie;
223 	bus_addr_t pageround;
224 	bus_size_t roundedsize;
225 	int i;
226 	bus_addr_t j;
227 
228 	for (i = 0; i < nsegs; i++) {
229 		pageround = trunc_page(segs[i].ds_addr);
230 		roundedsize = round_page(segs[i].ds_len +
231 		    (segs[i].ds_addr & PAGE_MASK));
232 
233 		if (papr_supports_stuff_tce) {
234 			phyp_hcall(H_STUFF_TCE, window->map->iobn, pageround, 0,
235 			    roundedsize/PAGE_SIZE);
236 		} else {
237 			for (j = 0; j < roundedsize; j += PAGE_SIZE)
238 				phyp_hcall(H_PUT_TCE, window->map->iobn,
239 				    pageround + j, 0);
240 		}
241 
242 		vmem_xfree(window->map->vmem, pageround, roundedsize);
243 	}
244 
245 	return (0);
246 }
247