1 /*
2 * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7 #include <arch.h>
8 #include <arch_helpers.h>
9 #include <assert.h>
10 #include <cassert.h>
11 #include <common_def.h>
12 #include <debug.h>
13 #include <platform_def.h>
14 #include <string.h>
15 #include <types.h>
16 #include <utils.h>
17 #include <xlat_tables.h>
18 #include "xlat_tables_private.h"
19
20 #if LOG_LEVEL >= LOG_LEVEL_VERBOSE
21 #define LVL0_SPACER ""
22 #define LVL1_SPACER " "
23 #define LVL2_SPACER " "
24 #define LVL3_SPACER " "
25 #define get_level_spacer(level) \
26 (((level) == U(0)) ? LVL0_SPACER : \
27 (((level) == U(1)) ? LVL1_SPACER : \
28 (((level) == U(2)) ? LVL2_SPACER : LVL3_SPACER)))
29 #define debug_print(...) tf_printf(__VA_ARGS__)
30 #else
31 #define debug_print(...) ((void)0)
32 #endif
33
34 #define UNSET_DESC ~0ull
35
36 static uint64_t xlat_tables[MAX_XLAT_TABLES][XLAT_TABLE_ENTRIES]
37 __aligned(XLAT_TABLE_SIZE) __section("xlat_table");
38
39 static unsigned int next_xlat;
40 static unsigned long long xlat_max_pa;
41 static uintptr_t xlat_max_va;
42
43 static uint64_t execute_never_mask;
44
45 /*
46 * Array of all memory regions stored in order of ascending base address.
47 * The list is terminated by the first entry with size == 0.
48 */
49 static mmap_region_t mmap[MAX_MMAP_REGIONS + 1];
50
51
print_mmap(void)52 void print_mmap(void)
53 {
54 #if LOG_LEVEL >= LOG_LEVEL_VERBOSE
55 debug_print("mmap:\n");
56 mmap_region_t *mm = mmap;
57 while (mm->size) {
58 debug_print(" VA:%p PA:0x%llx size:0x%zx attr:0x%x\n",
59 (void *)mm->base_va, mm->base_pa,
60 mm->size, mm->attr);
61 ++mm;
62 };
63 debug_print("\n");
64 #endif
65 }
66
mmap_add_region(unsigned long long base_pa,uintptr_t base_va,size_t size,mmap_attr_t attr)67 void mmap_add_region(unsigned long long base_pa, uintptr_t base_va,
68 size_t size, mmap_attr_t attr)
69 {
70 mmap_region_t *mm = mmap;
71 mmap_region_t *mm_last = mm + ARRAY_SIZE(mmap) - 1;
72 unsigned long long end_pa = base_pa + size - 1;
73 uintptr_t end_va = base_va + size - 1;
74
75 assert(IS_PAGE_ALIGNED(base_pa));
76 assert(IS_PAGE_ALIGNED(base_va));
77 assert(IS_PAGE_ALIGNED(size));
78
79 if (!size)
80 return;
81
82 assert(base_pa < end_pa); /* Check for overflows */
83 assert(base_va < end_va);
84
85 assert((base_va + (uintptr_t)size - (uintptr_t)1) <=
86 (PLAT_VIRT_ADDR_SPACE_SIZE - 1));
87 assert((base_pa + (unsigned long long)size - 1ULL) <=
88 (PLAT_PHY_ADDR_SPACE_SIZE - 1));
89
90 #if ENABLE_ASSERTIONS
91
92 /* Check for PAs and VAs overlaps with all other regions */
93 for (mm = mmap; mm->size; ++mm) {
94
95 uintptr_t mm_end_va = mm->base_va + mm->size - 1;
96
97 /*
98 * Check if one of the regions is completely inside the other
99 * one.
100 */
101 int fully_overlapped_va =
102 ((base_va >= mm->base_va) && (end_va <= mm_end_va)) ||
103 ((mm->base_va >= base_va) && (mm_end_va <= end_va));
104
105 /*
106 * Full VA overlaps are only allowed if both regions are
107 * identity mapped (zero offset) or have the same VA to PA
108 * offset. Also, make sure that it's not the exact same area.
109 */
110 if (fully_overlapped_va) {
111 assert((mm->base_va - mm->base_pa) ==
112 (base_va - base_pa));
113 assert((base_va != mm->base_va) || (size != mm->size));
114 } else {
115 /*
116 * If the regions do not have fully overlapping VAs,
117 * then they must have fully separated VAs and PAs.
118 * Partial overlaps are not allowed
119 */
120
121 unsigned long long mm_end_pa =
122 mm->base_pa + mm->size - 1;
123
124 int separated_pa =
125 (end_pa < mm->base_pa) || (base_pa > mm_end_pa);
126 int separated_va =
127 (end_va < mm->base_va) || (base_va > mm_end_va);
128
129 assert(separated_va && separated_pa);
130 }
131 }
132
133 mm = mmap; /* Restore pointer to the start of the array */
134
135 #endif /* ENABLE_ASSERTIONS */
136
137 /* Find correct place in mmap to insert new region */
138 while (mm->base_va < base_va && mm->size)
139 ++mm;
140
141 /*
142 * If a section is contained inside another one with the same base
143 * address, it must be placed after the one it is contained in:
144 *
145 * 1st |-----------------------|
146 * 2nd |------------|
147 * 3rd |------|
148 *
149 * This is required for mmap_region_attr() to get the attributes of the
150 * small region correctly.
151 */
152 while ((mm->base_va == base_va) && (mm->size > size))
153 ++mm;
154
155 /* Make room for new region by moving other regions up by one place */
156 memmove(mm + 1, mm, (uintptr_t)mm_last - (uintptr_t)mm);
157
158 /* Check we haven't lost the empty sentinal from the end of the array */
159 assert(mm_last->size == 0);
160
161 mm->base_pa = base_pa;
162 mm->base_va = base_va;
163 mm->size = size;
164 mm->attr = attr;
165
166 if (end_pa > xlat_max_pa)
167 xlat_max_pa = end_pa;
168 if (end_va > xlat_max_va)
169 xlat_max_va = end_va;
170 }
171
mmap_add(const mmap_region_t * mm)172 void mmap_add(const mmap_region_t *mm)
173 {
174 while (mm->size) {
175 mmap_add_region(mm->base_pa, mm->base_va, mm->size, mm->attr);
176 ++mm;
177 }
178 }
179
mmap_desc(mmap_attr_t attr,unsigned long long addr_pa,unsigned int level)180 static uint64_t mmap_desc(mmap_attr_t attr, unsigned long long addr_pa,
181 unsigned int level)
182 {
183 uint64_t desc;
184 int mem_type;
185
186 /* Make sure that the granularity is fine enough to map this address. */
187 assert((addr_pa & XLAT_BLOCK_MASK(level)) == 0);
188
189 desc = addr_pa;
190 /*
191 * There are different translation table descriptors for level 3 and the
192 * rest.
193 */
194 desc |= (level == XLAT_TABLE_LEVEL_MAX) ? PAGE_DESC : BLOCK_DESC;
195 desc |= (attr & MT_NS) ? LOWER_ATTRS(NS) : 0;
196 desc |= (attr & MT_RW) ? LOWER_ATTRS(AP_RW) : LOWER_ATTRS(AP_RO);
197 desc |= LOWER_ATTRS(ACCESS_FLAG);
198
199 /*
200 * Deduce shareability domain and executability of the memory region
201 * from the memory type.
202 *
203 * Data accesses to device memory and non-cacheable normal memory are
204 * coherent for all observers in the system, and correspondingly are
205 * always treated as being Outer Shareable. Therefore, for these 2 types
206 * of memory, it is not strictly needed to set the shareability field
207 * in the translation tables.
208 */
209 mem_type = MT_TYPE(attr);
210 if (mem_type == MT_DEVICE) {
211 desc |= LOWER_ATTRS(ATTR_DEVICE_INDEX | OSH);
212 /*
213 * Always map device memory as execute-never.
214 * This is to avoid the possibility of a speculative instruction
215 * fetch, which could be an issue if this memory region
216 * corresponds to a read-sensitive peripheral.
217 */
218 desc |= execute_never_mask;
219
220 } else { /* Normal memory */
221 /*
222 * Always map read-write normal memory as execute-never.
223 * (Trusted Firmware doesn't self-modify its code, therefore
224 * R/W memory is reserved for data storage, which must not be
225 * executable.)
226 * Note that setting the XN bit here is for consistency only.
227 * The function that enables the MMU sets the SCTLR_ELx.WXN bit,
228 * which makes any writable memory region to be treated as
229 * execute-never, regardless of the value of the XN bit in the
230 * translation table.
231 *
232 * For read-only memory, rely on the MT_EXECUTE/MT_EXECUTE_NEVER
233 * attribute to figure out the value of the XN bit.
234 */
235 if ((attr & MT_RW) || (attr & MT_EXECUTE_NEVER)) {
236 desc |= execute_never_mask;
237 }
238
239 if (mem_type == MT_MEMORY) {
240 desc |= LOWER_ATTRS(ATTR_IWBWA_OWBWA_NTR_INDEX | ISH);
241 } else {
242 assert(mem_type == MT_NON_CACHEABLE);
243 desc |= LOWER_ATTRS(ATTR_NON_CACHEABLE_INDEX | OSH);
244 }
245 }
246
247 debug_print((mem_type == MT_MEMORY) ? "MEM" :
248 ((mem_type == MT_NON_CACHEABLE) ? "NC" : "DEV"));
249 debug_print(attr & MT_RW ? "-RW" : "-RO");
250 debug_print(attr & MT_NS ? "-NS" : "-S");
251 debug_print(attr & MT_EXECUTE_NEVER ? "-XN" : "-EXEC");
252 return desc;
253 }
254
255 /*
256 * Look for the innermost region that contains the area at `base_va` with size
257 * `size`. Populate *attr with the attributes of this region.
258 *
259 * On success, this function returns 0.
260 * If there are partial overlaps (meaning that a smaller size is needed) or if
261 * the region can't be found in the given area, it returns -1. In this case the
262 * value pointed by attr should be ignored by the caller.
263 */
mmap_region_attr(mmap_region_t * mm,uintptr_t base_va,size_t size,mmap_attr_t * attr)264 static int mmap_region_attr(mmap_region_t *mm, uintptr_t base_va,
265 size_t size, mmap_attr_t *attr)
266 {
267 /* Don't assume that the area is contained in the first region */
268 int ret = -1;
269
270 /*
271 * Get attributes from last (innermost) region that contains the
272 * requested area. Don't stop as soon as one region doesn't contain it
273 * because there may be other internal regions that contain this area:
274 *
275 * |-----------------------------1-----------------------------|
276 * |----2----| |-------3-------| |----5----|
277 * |--4--|
278 *
279 * |---| <- Area we want the attributes of.
280 *
281 * In this example, the area is contained in regions 1, 3 and 4 but not
282 * in region 2. The loop shouldn't stop at region 2 as inner regions
283 * have priority over outer regions, it should stop at region 5.
284 */
285 for (;; ++mm) {
286
287 if (!mm->size)
288 return ret; /* Reached end of list */
289
290 if (mm->base_va > base_va + size - 1)
291 return ret; /* Next region is after area so end */
292
293 if (mm->base_va + mm->size - 1 < base_va)
294 continue; /* Next region has already been overtaken */
295
296 if (!ret && mm->attr == *attr)
297 continue; /* Region doesn't override attribs so skip */
298
299 if (mm->base_va > base_va ||
300 mm->base_va + mm->size - 1 < base_va + size - 1)
301 return -1; /* Region doesn't fully cover our area */
302
303 *attr = mm->attr;
304 ret = 0;
305 }
306 return ret;
307 }
308
init_xlation_table_inner(mmap_region_t * mm,uintptr_t base_va,uint64_t * table,unsigned int level)309 static mmap_region_t *init_xlation_table_inner(mmap_region_t *mm,
310 uintptr_t base_va,
311 uint64_t *table,
312 unsigned int level)
313 {
314 assert(level >= XLAT_TABLE_LEVEL_MIN && level <= XLAT_TABLE_LEVEL_MAX);
315
316 unsigned int level_size_shift =
317 L0_XLAT_ADDRESS_SHIFT - level * XLAT_TABLE_ENTRIES_SHIFT;
318 u_register_t level_size = (u_register_t)1 << level_size_shift;
319 u_register_t level_index_mask =
320 ((u_register_t)XLAT_TABLE_ENTRIES_MASK) << level_size_shift;
321
322 debug_print("New xlat table:\n");
323
324 do {
325 uint64_t desc = UNSET_DESC;
326
327 if (!mm->size) {
328 /* Done mapping regions; finish zeroing the table */
329 desc = INVALID_DESC;
330 } else if (mm->base_va + mm->size - 1 < base_va) {
331 /* This area is after the region so get next region */
332 ++mm;
333 continue;
334 }
335
336 debug_print("%s VA:%p size:0x%llx ", get_level_spacer(level),
337 (void *)base_va, (unsigned long long)level_size);
338
339 if (mm->base_va > base_va + level_size - 1) {
340 /* Next region is after this area. Nothing to map yet */
341 desc = INVALID_DESC;
342 /* Make sure that the current level allows block descriptors */
343 } else if (level >= XLAT_BLOCK_LEVEL_MIN) {
344 /*
345 * Try to get attributes of this area. It will fail if
346 * there are partially overlapping regions. On success,
347 * it will return the innermost region's attributes.
348 */
349 mmap_attr_t attr;
350 int r = mmap_region_attr(mm, base_va, level_size, &attr);
351
352 if (!r) {
353 desc = mmap_desc(attr,
354 base_va - mm->base_va + mm->base_pa,
355 level);
356 }
357 }
358
359 if (desc == UNSET_DESC) {
360 /* Area not covered by a region so need finer table */
361 uint64_t *new_table = xlat_tables[next_xlat++];
362 assert(next_xlat <= MAX_XLAT_TABLES);
363 desc = TABLE_DESC | (uintptr_t)new_table;
364
365 /* Recurse to fill in new table */
366 mm = init_xlation_table_inner(mm, base_va,
367 new_table, level+1);
368 }
369
370 debug_print("\n");
371
372 *table++ = desc;
373 base_va += level_size;
374 } while ((base_va & level_index_mask) &&
375 (base_va - 1 < PLAT_VIRT_ADDR_SPACE_SIZE - 1));
376
377 return mm;
378 }
379
init_xlation_table(uintptr_t base_va,uint64_t * table,unsigned int level,uintptr_t * max_va,unsigned long long * max_pa)380 void init_xlation_table(uintptr_t base_va, uint64_t *table,
381 unsigned int level, uintptr_t *max_va,
382 unsigned long long *max_pa)
383 {
384 execute_never_mask = xlat_arch_get_xn_desc(xlat_arch_current_el());
385 init_xlation_table_inner(mmap, base_va, table, level);
386 *max_va = xlat_max_va;
387 *max_pa = xlat_max_pa;
388 }
389