FreeBSD/Linux Kernel Cross Reference
sys/arm/arm/devmap.c
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: releng/10.2/sys/arm/arm/devmap.c 266086 2014-05-14 20:17:31Z ian $");
29
30 /*
31 * Routines for mapping device memory.
32 */
33
34 #include "opt_ddb.h"
35
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <vm/vm.h>
39 #include <vm/vm_extern.h>
40 #include <vm/pmap.h>
41 #include <machine/armreg.h>
42 #include <machine/devmap.h>
43
44 static const struct arm_devmap_entry *devmap_table;
45 static boolean_t devmap_bootstrap_done = false;
46
47 /*
48 * The allocated-kva (akva) devmap table and metadata. Platforms can call
49 * arm_devmap_add_entry() to add static device mappings to this table using
50 * automatically allocated virtual addresses carved out of the top of kva space.
51 * Allocation begins immediately below the ARM_VECTORS_HIGH address.
52 */
53 #define AKVA_DEVMAP_MAX_ENTRIES 32
54 static struct arm_devmap_entry akva_devmap_entries[AKVA_DEVMAP_MAX_ENTRIES];
55 static u_int akva_devmap_idx;
56 static vm_offset_t akva_devmap_vaddr = ARM_VECTORS_HIGH;
57
58 /*
59 * Print the contents of the static mapping table using the provided printf-like
60 * output function (which will be either printf or db_printf).
61 */
62 static void
63 devmap_dump_table(int (*prfunc)(const char *, ...))
64 {
65 const struct arm_devmap_entry *pd;
66
67 if (devmap_table == NULL || devmap_table[0].pd_size == 0) {
68 prfunc("No static device mappings.\n");
69 return;
70 }
71
72 prfunc("Static device mappings:\n");
73 for (pd = devmap_table; pd->pd_size != 0; ++pd) {
74 prfunc(" 0x%08x - 0x%08x mapped at VA 0x%08x\n",
75 pd->pd_pa, pd->pd_pa + pd->pd_size - 1, pd->pd_va);
76 }
77 }
78
79 /*
80 * Print the contents of the static mapping table. Used for bootverbose.
81 */
82 void
83 arm_devmap_print_table()
84 {
85 devmap_dump_table(printf);
86 }
87
88 /*
89 * Return the "last" kva address used by the registered devmap table. It's
90 * actually the lowest address used by the static mappings, i.e., the address of
91 * the first unusable byte of KVA.
92 */
93 vm_offset_t
94 arm_devmap_lastaddr()
95 {
96 const struct arm_devmap_entry *pd;
97 vm_offset_t lowaddr;
98
99 if (akva_devmap_idx > 0)
100 return (akva_devmap_vaddr);
101
102 lowaddr = ARM_VECTORS_HIGH;
103 for (pd = devmap_table; pd != NULL && pd->pd_size != 0; ++pd) {
104 if (lowaddr > pd->pd_va)
105 lowaddr = pd->pd_va;
106 }
107
108 return (lowaddr);
109 }
110
111 /*
112 * Add an entry to the internal "akva" static devmap table using the given
113 * physical address and size and a virtual address allocated from the top of
114 * kva. This automatically registers the akva table on the first call, so all a
115 * platform has to do is call this routine to install as many mappings as it
116 * needs and when initarm() calls arm_devmap_bootstrap() it will pick up all the
117 * entries in the akva table automatically.
118 */
119 void
120 arm_devmap_add_entry(vm_paddr_t pa, vm_size_t sz)
121 {
122 struct arm_devmap_entry *m;
123
124 if (devmap_bootstrap_done)
125 panic("arm_devmap_add_entry() after arm_devmap_bootstrap()");
126
127 if (akva_devmap_idx == (AKVA_DEVMAP_MAX_ENTRIES - 1))
128 panic("AKVA_DEVMAP_MAX_ENTRIES is too small");
129
130 if (akva_devmap_idx == 0)
131 arm_devmap_register_table(akva_devmap_entries);
132
133 /*
134 * Allocate virtual address space from the top of kva downwards. If the
135 * range being mapped is aligned and sized to 1MB boundaries then also
136 * align the virtual address to the next-lower 1MB boundary so that we
137 * end up with a nice efficient section mapping.
138 */
139 if ((pa & 0x000fffff) == 0 && (sz & 0x000fffff) == 0) {
140 akva_devmap_vaddr = trunc_1mpage(akva_devmap_vaddr - sz);
141 } else {
142 akva_devmap_vaddr = trunc_page(akva_devmap_vaddr - sz);
143 }
144 m = &akva_devmap_entries[akva_devmap_idx++];
145 m->pd_va = akva_devmap_vaddr;
146 m->pd_pa = pa;
147 m->pd_size = sz;
148 m->pd_prot = VM_PROT_READ | VM_PROT_WRITE;
149 m->pd_cache = PTE_DEVICE;
150 }
151
152 /*
153 * Register the given table as the one to use in arm_devmap_bootstrap().
154 */
155 void
156 arm_devmap_register_table(const struct arm_devmap_entry *table)
157 {
158
159 devmap_table = table;
160 }
161
162 /*
163 * Map all of the static regions in the devmap table, and remember the devmap
164 * table so the mapdev, ptov, and vtop functions can do lookups later.
165 *
166 * If a non-NULL table pointer is given it is used unconditionally, otherwise
167 * the previously-registered table is used. This smooths transition from legacy
168 * code that fills in a local table then calls this function passing that table,
169 * and newer code that uses arm_devmap_register_table() in platform-specific
170 * code, then lets the common initarm() call this function with a NULL pointer.
171 */
172 void
173 arm_devmap_bootstrap(vm_offset_t l1pt, const struct arm_devmap_entry *table)
174 {
175 const struct arm_devmap_entry *pd;
176
177 devmap_bootstrap_done = true;
178
179 /*
180 * If given a table pointer, use it. Otherwise, if a table was
181 * previously registered, use it. Otherwise, no work to do.
182 */
183 if (table != NULL)
184 devmap_table = table;
185 else if (devmap_table == NULL)
186 return;
187
188 for (pd = devmap_table; pd->pd_size != 0; ++pd) {
189 pmap_map_chunk(l1pt, pd->pd_va, pd->pd_pa, pd->pd_size,
190 pd->pd_prot,pd->pd_cache);
191 }
192 }
193
194 /*
195 * Look up the given physical address in the static mapping data and return the
196 * corresponding virtual address, or NULL if not found.
197 */
198 void *
199 arm_devmap_ptov(vm_paddr_t pa, vm_size_t size)
200 {
201 const struct arm_devmap_entry *pd;
202
203 if (devmap_table == NULL)
204 return (NULL);
205
206 for (pd = devmap_table; pd->pd_size != 0; ++pd) {
207 if (pa >= pd->pd_pa && pa + size <= pd->pd_pa + pd->pd_size)
208 return ((void *)(pd->pd_va + (pa - pd->pd_pa)));
209 }
210
211 return (NULL);
212 }
213
214 /*
215 * Look up the given virtual address in the static mapping data and return the
216 * corresponding physical address, or DEVMAP_PADDR_NOTFOUND if not found.
217 */
218 vm_paddr_t
219 arm_devmap_vtop(void * vpva, vm_size_t size)
220 {
221 const struct arm_devmap_entry *pd;
222 vm_offset_t va;
223
224 if (devmap_table == NULL)
225 return (DEVMAP_PADDR_NOTFOUND);
226
227 va = (vm_offset_t)vpva;
228 for (pd = devmap_table; pd->pd_size != 0; ++pd) {
229 if (va >= pd->pd_va && va + size <= pd->pd_va + pd->pd_size)
230 return ((vm_paddr_t)(pd->pd_pa + (va - pd->pd_va)));
231 }
232
233 return (DEVMAP_PADDR_NOTFOUND);
234 }
235
236 /*
237 * Map a set of physical memory pages into the kernel virtual address space.
238 * Return a pointer to where it is mapped.
239 *
240 * This uses a pre-established static mapping if one exists for the requested
241 * range, otherwise it allocates kva space and maps the physical pages into it.
242 *
243 * This routine is intended to be used for mapping device memory, NOT real
244 * memory; the mapping type is inherently PTE_DEVICE in pmap_kenter_device().
245 */
246 void *
247 pmap_mapdev(vm_offset_t pa, vm_size_t size)
248 {
249 vm_offset_t va, tmpva, offset;
250 void * rva;
251
252 /* First look in the static mapping table. */
253 if ((rva = arm_devmap_ptov(pa, size)) != NULL)
254 return (rva);
255
256 offset = pa & PAGE_MASK;
257 pa = trunc_page(pa);
258 size = round_page(size + offset);
259
260 va = kva_alloc(size);
261 if (!va)
262 panic("pmap_mapdev: Couldn't alloc kernel virtual memory");
263
264 for (tmpva = va; size > 0;) {
265 pmap_kenter_device(tmpva, pa);
266 size -= PAGE_SIZE;
267 tmpva += PAGE_SIZE;
268 pa += PAGE_SIZE;
269 }
270
271 return ((void *)(va + offset));
272 }
273
274 /*
275 * Unmap device memory and free the kva space.
276 */
277 void
278 pmap_unmapdev(vm_offset_t va, vm_size_t size)
279 {
280 vm_offset_t tmpva, offset;
281 vm_size_t origsize;
282
283 /* Nothing to do if we find the mapping in the static table. */
284 if (arm_devmap_vtop((void*)va, size) != DEVMAP_PADDR_NOTFOUND)
285 return;
286
287 origsize = size;
288 offset = va & PAGE_MASK;
289 va = trunc_page(va);
290 size = round_page(size + offset);
291
292 for (tmpva = va; size > 0;) {
293 pmap_kremove(tmpva);
294 size -= PAGE_SIZE;
295 tmpva += PAGE_SIZE;
296 }
297
298 kva_free(va, origsize);
299 }
300
301 #ifdef DDB
302 #include <ddb/ddb.h>
303
304 DB_SHOW_COMMAND(devmap, db_show_devmap)
305 {
306 devmap_dump_table(db_printf);
307 }
308
309 #endif /* DDB */
310
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