xref: /freebsd/sys/powerpc/pseries/plpar_iommu.c (revision 43faedc1339a9624c7acedb7f3e5624e64da5b99)
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 
46 MALLOC_DEFINE(M_PHYPIOMMU, "iommu", "IOMMU data for PAPR LPARs");
47 
48 struct papr_iommu_map {
49 	uint32_t iobn;
50 	vmem_t *vmem;
51 	struct papr_iommu_map *next;
52 };
53 
54 static SLIST_HEAD(iommu_maps, iommu_map) iommu_map_head =
55     SLIST_HEAD_INITIALIZER(iommu_map_head);
56 static int papr_supports_stuff_tce = -1;
57 
58 struct iommu_map {
59 	uint32_t iobn;
60 	vmem_t *vmem;
61 
62 	SLIST_ENTRY(iommu_map) entries;
63 };
64 
65 struct dma_window {
66 	struct iommu_map *map;
67 	bus_addr_t start;
68 	bus_addr_t end;
69 };
70 
71 int
72 phyp_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_getencprop(node, "ibm,#dma-size-cells", &dma_scells,
92 	    sizeof(cell_t)) <= 0)
93 		OF_searchencprop(node, "#size-cells", &dma_scells,
94 		    sizeof(cell_t));
95 	if (OF_getencprop(node, "ibm,#dma-address-cells", &dma_acells,
96 	    sizeof(cell_t)) <= 0)
97 		OF_searchencprop(node, "#address-cells", &dma_acells,
98 		    sizeof(cell_t));
99 
100 	if (ofw_bus_has_prop(p, "ibm,my-dma-window"))
101 		OF_getencprop(node, "ibm,my-dma-window", dmawindow,
102 		    sizeof(cell_t)*(dma_scells + dma_acells + 1));
103 	else
104 		OF_getencprop(node, "ibm,dma-window", dmawindow,
105 		    sizeof(cell_t)*(dma_scells + dma_acells + 1));
106 
107 	struct dma_window *window = malloc(sizeof(struct dma_window),
108 	    M_PHYPIOMMU, M_WAITOK);
109 	window->start = 0;
110 	for (cell = 1; cell < 1 + dma_acells; cell++) {
111 		window->start <<= 32;
112 		window->start |= dmawindow[cell];
113 	}
114 	window->end = 0;
115 	for (; cell < 1 + dma_acells + dma_scells; cell++) {
116 		window->end <<= 32;
117 		window->end |= dmawindow[cell];
118 	}
119 	window->end += window->start;
120 
121 	if (bootverbose)
122 		device_printf(dev, "Mapping IOMMU domain %#x\n", dmawindow[0]);
123 	window->map = NULL;
124 	SLIST_FOREACH(i, &iommu_map_head, entries) {
125 		if (i->iobn == dmawindow[0]) {
126 			window->map = i;
127 			break;
128 		}
129 	}
130 
131 	if (window->map == NULL) {
132 		window->map = malloc(sizeof(struct iommu_map), M_PHYPIOMMU,
133 		    M_WAITOK);
134 		window->map->iobn = dmawindow[0];
135 		/*
136 		 * Allocate IOMMU range beginning at PAGE_SIZE. Some drivers
137 		 * (em(4), for example) do not like getting mappings at 0.
138 		 */
139 		window->map->vmem = vmem_create("IOMMU mappings", PAGE_SIZE,
140 		    trunc_page(VMEM_ADDR_MAX) - PAGE_SIZE, PAGE_SIZE, 0,
141 		    M_BESTFIT | M_NOWAIT);
142 		SLIST_INSERT_HEAD(&iommu_map_head, window->map, entries);
143 	}
144 
145 	/*
146 	 * Check experimentally whether we can use H_STUFF_TCE. It is required
147 	 * by the spec but some firmware (e.g. QEMU) does not actually support
148 	 * it
149 	 */
150 	if (papr_supports_stuff_tce == -1)
151 		papr_supports_stuff_tce = !(phyp_hcall(H_STUFF_TCE,
152 		    window->map->iobn, 0, 0, 0) == H_FUNCTION);
153 
154 	bus_dma_tag_set_iommu(tag, bus, window);
155 
156 	return (0);
157 }
158 
159 int
160 phyp_iommu_map(device_t dev, bus_dma_segment_t *segs, int *nsegs,
161     bus_addr_t min, bus_addr_t max, bus_size_t alignment, bus_addr_t boundary,
162     void *cookie)
163 {
164 	struct dma_window *window = cookie;
165 	bus_addr_t minaddr, maxaddr;
166 	bus_addr_t alloced;
167 	bus_size_t allocsize;
168 	int error, i, j;
169 	uint64_t tce;
170 	minaddr = window->start;
171 	maxaddr = window->end;
172 
173 	/* XXX: handle exclusion range in a more useful way */
174 	if (min < maxaddr)
175 		maxaddr = min;
176 
177 	/* XXX: consolidate segs? */
178 	for (i = 0; i < *nsegs; i++) {
179 		allocsize = round_page(segs[i].ds_len +
180 		    (segs[i].ds_addr & PAGE_MASK));
181 		error = vmem_xalloc(window->map->vmem, allocsize,
182 		    (alignment < PAGE_SIZE) ? PAGE_SIZE : alignment, 0,
183 		    boundary, minaddr, maxaddr, M_BESTFIT | M_NOWAIT, &alloced);
184 		if (error != 0) {
185 			panic("VMEM failure: %d\n", error);
186 			return (error);
187 		}
188 		KASSERT(alloced % PAGE_SIZE == 0, ("Alloc not page aligned"));
189 		KASSERT((alloced + (segs[i].ds_addr & PAGE_MASK)) %
190 		    alignment == 0,
191 		    ("Allocated segment does not match alignment constraint"));
192 
193 		tce = trunc_page(segs[i].ds_addr);
194 		tce |= 0x3; /* read/write */
195 		for (j = 0; j < allocsize; j += PAGE_SIZE) {
196 			error = phyp_hcall(H_PUT_TCE, window->map->iobn,
197 			    alloced + j, tce + j);
198 			if (error < 0) {
199 				panic("IOMMU mapping error: %d\n", error);
200 				return (ENOMEM);
201 			}
202 		}
203 
204 		segs[i].ds_addr = alloced + (segs[i].ds_addr & PAGE_MASK);
205 		KASSERT(segs[i].ds_addr > 0, ("Address needs to be positive"));
206 		KASSERT(segs[i].ds_addr + segs[i].ds_len < maxaddr,
207 		    ("Address not in range"));
208 		if (error < 0) {
209 			panic("IOMMU mapping error: %d\n", error);
210 			return (ENOMEM);
211 		}
212 	}
213 
214 	return (0);
215 }
216 
217 int
218 phyp_iommu_unmap(device_t dev, bus_dma_segment_t *segs, int nsegs, void *cookie)
219 {
220 	struct dma_window *window = cookie;
221 	bus_addr_t pageround;
222 	bus_size_t roundedsize;
223 	int i;
224 	bus_addr_t j;
225 
226 	for (i = 0; i < nsegs; i++) {
227 		pageround = trunc_page(segs[i].ds_addr);
228 		roundedsize = round_page(segs[i].ds_len +
229 		    (segs[i].ds_addr & PAGE_MASK));
230 
231 		if (papr_supports_stuff_tce) {
232 			phyp_hcall(H_STUFF_TCE, window->map->iobn, pageround, 0,
233 			    roundedsize/PAGE_SIZE);
234 		} else {
235 			for (j = 0; j < roundedsize; j += PAGE_SIZE)
236 				phyp_hcall(H_PUT_TCE, window->map->iobn,
237 				    pageround + j, 0);
238 		}
239 
240 		vmem_xfree(window->map->vmem, pageround, roundedsize);
241 	}
242 
243 	return (0);
244 }
245 
246