1 /*-
2 * Copyright (c) 2013 Ian Lepore <ian@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, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 /* Routines for mapping device memory. */
31
32 #include "opt_ddb.h"
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/devmap.h>
37 #include <vm/vm.h>
38 #include <vm/vm_extern.h>
39 #include <vm/pmap.h>
40 #include <machine/vmparam.h>
41
42 static const struct devmap_entry *devmap_table;
43 static boolean_t devmap_bootstrap_done = false;
44
45 /*
46 * The allocated-kva (akva) devmap table and metadata. Platforms can call
47 * devmap_add_entry() to add static device mappings to this table using
48 * automatically allocated virtual addresses carved out of the top of kva space.
49 * Allocation begins immediately below the ARM_VECTORS_HIGH address.
50 */
51 #define AKVA_DEVMAP_MAX_ENTRIES 32
52 static struct devmap_entry akva_devmap_entries[AKVA_DEVMAP_MAX_ENTRIES];
53 static u_int akva_devmap_idx;
54 static vm_offset_t akva_devmap_vaddr = DEVMAP_MAX_VADDR;
55
56 #if defined(__aarch64__) || defined(__riscv__)
57 extern int early_boot;
58 #endif
59
60 /*
61 * Print the contents of the static mapping table using the provided printf-like
62 * output function (which will be either printf or db_printf).
63 */
64 static void
65 devmap_dump_table(int (*prfunc)(const char *, ...))
66 {
67 const struct devmap_entry *pd;
68
69 if (devmap_table == NULL || devmap_table[0].pd_size == 0) {
70 prfunc("No static device mappings.\n");
71 return;
72 }
73
74 prfunc("Static device mappings:\n");
75 for (pd = devmap_table; pd->pd_size != 0; ++pd) {
76 prfunc(" 0x%08x - 0x%08x mapped at VA 0x%08x\n",
77 pd->pd_pa, pd->pd_pa + pd->pd_size - 1, pd->pd_va);
78 }
79 }
80
81 /*
82 * Print the contents of the static mapping table. Used for bootverbose.
83 */
84 void
85 devmap_print_table()
86 {
87 devmap_dump_table(printf);
88 }
89
90 /*
91 * Return the "last" kva address used by the registered devmap table. It's
92 * actually the lowest address used by the static mappings, i.e., the address of
93 * the first unusable byte of KVA.
94 */
95 vm_offset_t
96 devmap_lastaddr()
97 {
98 const struct devmap_entry *pd;
99 vm_offset_t lowaddr;
100
101 if (akva_devmap_idx > 0)
102 return (akva_devmap_vaddr);
103
104 lowaddr = DEVMAP_MAX_VADDR;
105 for (pd = devmap_table; pd != NULL && pd->pd_size != 0; ++pd) {
106 if (lowaddr > pd->pd_va)
107 lowaddr = pd->pd_va;
108 }
109
110 return (lowaddr);
111 }
112
113 /*
114 * Add an entry to the internal "akva" static devmap table using the given
115 * physical address and size and a virtual address allocated from the top of
116 * kva. This automatically registers the akva table on the first call, so all a
117 * platform has to do is call this routine to install as many mappings as it
118 * needs and when initarm() calls devmap_bootstrap() it will pick up all the
119 * entries in the akva table automatically.
120 */
121 void
122 devmap_add_entry(vm_paddr_t pa, vm_size_t sz)
123 {
124 struct devmap_entry *m;
125
126 if (devmap_bootstrap_done)
127 panic("devmap_add_entry() after devmap_bootstrap()");
128
129 if (akva_devmap_idx == (AKVA_DEVMAP_MAX_ENTRIES - 1))
130 panic("AKVA_DEVMAP_MAX_ENTRIES is too small");
131
132 if (akva_devmap_idx == 0)
133 devmap_register_table(akva_devmap_entries);
134
135 /*
136 * Allocate virtual address space from the top of kva downwards. If the
137 * range being mapped is aligned and sized to 1MB boundaries then also
138 * align the virtual address to the next-lower 1MB boundary so that we
139 * end up with a nice efficient section mapping.
140 */
141 #ifdef __arm__
142 if ((pa & 0x000fffff) == 0 && (sz & 0x000fffff) == 0) {
143 akva_devmap_vaddr = trunc_1mpage(akva_devmap_vaddr - sz);
144 } else
145 #endif
146 {
147 akva_devmap_vaddr = trunc_page(akva_devmap_vaddr - sz);
148 }
149 m = &akva_devmap_entries[akva_devmap_idx++];
150 m->pd_va = akva_devmap_vaddr;
151 m->pd_pa = pa;
152 m->pd_size = sz;
153 }
154
155 /*
156 * Register the given table as the one to use in devmap_bootstrap().
157 */
158 void
159 devmap_register_table(const struct devmap_entry *table)
160 {
161
162 devmap_table = table;
163 }
164
165 /*
166 * Map all of the static regions in the devmap table, and remember the devmap
167 * table so the mapdev, ptov, and vtop functions can do lookups later.
168 *
169 * If a non-NULL table pointer is given it is used unconditionally, otherwise
170 * the previously-registered table is used. This smooths transition from legacy
171 * code that fills in a local table then calls this function passing that table,
172 * and newer code that uses devmap_register_table() in platform-specific
173 * code, then lets the common initarm() call this function with a NULL pointer.
174 */
175 void
176 devmap_bootstrap(vm_offset_t l1pt, const struct devmap_entry *table)
177 {
178 const struct devmap_entry *pd;
179
180 devmap_bootstrap_done = true;
181
182 /*
183 * If given a table pointer, use it. Otherwise, if a table was
184 * previously registered, use it. Otherwise, no work to do.
185 */
186 if (table != NULL)
187 devmap_table = table;
188 else if (devmap_table == NULL)
189 return;
190
191 for (pd = devmap_table; pd->pd_size != 0; ++pd) {
192 #if defined(__arm__)
193 #if __ARM_ARCH >= 6
194 pmap_preboot_map_attr(pd->pd_pa, pd->pd_va, pd->pd_size,
195 VM_PROT_READ | VM_PROT_WRITE, VM_MEMATTR_DEVICE);
196 #else
197 pmap_map_chunk(l1pt, pd->pd_va, pd->pd_pa, pd->pd_size,
198 VM_PROT_READ | VM_PROT_WRITE, PTE_DEVICE);
199 #endif
200 #elif defined(__aarch64__) || defined(__riscv__)
201 pmap_kenter_device(pd->pd_va, pd->pd_size, pd->pd_pa);
202 #endif
203 }
204 }
205
206 /*
207 * Look up the given physical address in the static mapping data and return the
208 * corresponding virtual address, or NULL if not found.
209 */
210 void *
211 devmap_ptov(vm_paddr_t pa, vm_size_t size)
212 {
213 const struct devmap_entry *pd;
214
215 if (devmap_table == NULL)
216 return (NULL);
217
218 for (pd = devmap_table; pd->pd_size != 0; ++pd) {
219 if (pa >= pd->pd_pa && pa + size <= pd->pd_pa + pd->pd_size)
220 return ((void *)(pd->pd_va + (pa - pd->pd_pa)));
221 }
222
223 return (NULL);
224 }
225
226 /*
227 * Look up the given virtual address in the static mapping data and return the
228 * corresponding physical address, or DEVMAP_PADDR_NOTFOUND if not found.
229 */
230 vm_paddr_t
231 devmap_vtop(void * vpva, vm_size_t size)
232 {
233 const struct devmap_entry *pd;
234 vm_offset_t va;
235
236 if (devmap_table == NULL)
237 return (DEVMAP_PADDR_NOTFOUND);
238
239 va = (vm_offset_t)vpva;
240 for (pd = devmap_table; pd->pd_size != 0; ++pd) {
241 if (va >= pd->pd_va && va + size <= pd->pd_va + pd->pd_size)
242 return ((vm_paddr_t)(pd->pd_pa + (va - pd->pd_va)));
243 }
244
245 return (DEVMAP_PADDR_NOTFOUND);
246 }
247
248 /*
249 * Map a set of physical memory pages into the kernel virtual address space.
250 * Return a pointer to where it is mapped.
251 *
252 * This uses a pre-established static mapping if one exists for the requested
253 * range, otherwise it allocates kva space and maps the physical pages into it.
254 *
255 * This routine is intended to be used for mapping device memory, NOT real
256 * memory; the mapping type is inherently VM_MEMATTR_DEVICE in
257 * pmap_kenter_device().
258 */
259 void *
260 pmap_mapdev(vm_offset_t pa, vm_size_t size)
261 {
262 vm_offset_t va, offset;
263 void * rva;
264
265 /* First look in the static mapping table. */
266 if ((rva = devmap_ptov(pa, size)) != NULL)
267 return (rva);
268
269 offset = pa & PAGE_MASK;
270 pa = trunc_page(pa);
271 size = round_page(size + offset);
272
273 #if defined(__aarch64__) || defined(__riscv__)
274 if (early_boot) {
275 akva_devmap_vaddr = trunc_page(akva_devmap_vaddr - size);
276 va = akva_devmap_vaddr;
277 KASSERT(va >= VM_MAX_KERNEL_ADDRESS - L2_SIZE,
278 ("Too many early devmap mappings"));
279 } else
280 #endif
281 va = kva_alloc(size);
282 if (!va)
283 panic("pmap_mapdev: Couldn't alloc kernel virtual memory");
284
285 pmap_kenter_device(va, size, pa);
286
287 return ((void *)(va + offset));
288 }
289
290 /*
291 * Unmap device memory and free the kva space.
292 */
293 void
294 pmap_unmapdev(vm_offset_t va, vm_size_t size)
295 {
296 vm_offset_t offset;
297
298 /* Nothing to do if we find the mapping in the static table. */
299 if (devmap_vtop((void*)va, size) != DEVMAP_PADDR_NOTFOUND)
300 return;
301
302 offset = va & PAGE_MASK;
303 va = trunc_page(va);
304 size = round_page(size + offset);
305
306 pmap_kremove_device(va, size);
307 kva_free(va, size);
308 }
309
310 #ifdef DDB
311 #include <ddb/ddb.h>
312
313 DB_SHOW_COMMAND(devmap, db_show_devmap)
314 {
315 devmap_dump_table(db_printf);
316 }
317
318 #endif /* DDB */
319
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