aboutsummaryrefslogtreecommitdiff
path: root/lib/xlat_tables/xlat_tables_common.c
blob: 2ee77c7aebe967b6f9db0dfe0aa2c053fc75873b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
/*
 * Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <arch.h>
#include <arch_helpers.h>
#include <assert.h>
#include <cassert.h>
#include <common_def.h>
#include <debug.h>
#include <platform_def.h>
#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include <utils.h>
#include <xlat_tables.h>
#include "xlat_tables_private.h"

#if LOG_LEVEL >= LOG_LEVEL_VERBOSE
#define LVL0_SPACER ""
#define LVL1_SPACER "  "
#define LVL2_SPACER "    "
#define LVL3_SPACER "      "
#define get_level_spacer(level)		\
			(((level) == U(0)) ? LVL0_SPACER : \
			(((level) == U(1)) ? LVL1_SPACER : \
			(((level) == U(2)) ? LVL2_SPACER : LVL3_SPACER)))
#define debug_print(...) printf(__VA_ARGS__)
#else
#define debug_print(...) ((void)0)
#endif

#define UNSET_DESC	~0ULL
#define MT_UNKNOWN	~0U

static uint64_t xlat_tables[MAX_XLAT_TABLES][XLAT_TABLE_ENTRIES]
			__aligned(XLAT_TABLE_SIZE) __section("xlat_table");

static unsigned int next_xlat;
static unsigned long long xlat_max_pa;
static uintptr_t xlat_max_va;

static uint64_t execute_never_mask;
static uint64_t ap1_mask;

/*
 * Array of all memory regions stored in order of ascending base address.
 * The list is terminated by the first entry with size == 0.
 */
static mmap_region_t mmap[MAX_MMAP_REGIONS + 1];


void print_mmap(void)
{
#if LOG_LEVEL >= LOG_LEVEL_VERBOSE
	debug_print("mmap:\n");
	mmap_region_t *mm = mmap;
	while (mm->size != 0U) {
		debug_print(" VA:%p  PA:0x%llx  size:0x%zx  attr:0x%x\n",
				(void *)mm->base_va, mm->base_pa,
				mm->size, mm->attr);
		++mm;
	};
	debug_print("\n");
#endif
}

void mmap_add_region(unsigned long long base_pa, uintptr_t base_va,
		     size_t size, unsigned int attr)
{
	mmap_region_t *mm = mmap;
	const mmap_region_t *mm_last = mm + ARRAY_SIZE(mmap) - 1U;
	unsigned long long end_pa = base_pa + size - 1U;
	uintptr_t end_va = base_va + size - 1U;

	assert(IS_PAGE_ALIGNED(base_pa));
	assert(IS_PAGE_ALIGNED(base_va));
	assert(IS_PAGE_ALIGNED(size));

	if (size == 0U)
		return;

	assert(base_pa < end_pa); /* Check for overflows */
	assert(base_va < end_va);

	assert((base_va + (uintptr_t)size - (uintptr_t)1) <=
					(PLAT_VIRT_ADDR_SPACE_SIZE - 1U));
	assert((base_pa + (unsigned long long)size - 1ULL) <=
					(PLAT_PHY_ADDR_SPACE_SIZE - 1U));

#if ENABLE_ASSERTIONS

	/* Check for PAs and VAs overlaps with all other regions */
	for (mm = mmap; mm->size; ++mm) {

		uintptr_t mm_end_va = mm->base_va + mm->size - 1U;

		/*
		 * Check if one of the regions is completely inside the other
		 * one.
		 */
		bool fully_overlapped_va =
			((base_va >= mm->base_va) && (end_va <= mm_end_va)) ||
			((mm->base_va >= base_va) && (mm_end_va <= end_va));

		/*
		 * Full VA overlaps are only allowed if both regions are
		 * identity mapped (zero offset) or have the same VA to PA
		 * offset. Also, make sure that it's not the exact same area.
		 */
		if (fully_overlapped_va) {
			assert((mm->base_va - mm->base_pa) ==
			       (base_va - base_pa));
			assert((base_va != mm->base_va) || (size != mm->size));
		} else {
			/*
			 * If the regions do not have fully overlapping VAs,
			 * then they must have fully separated VAs and PAs.
			 * Partial overlaps are not allowed
			 */

			unsigned long long mm_end_pa =
						     mm->base_pa + mm->size - 1;

			bool separated_pa = (end_pa < mm->base_pa) ||
				(base_pa > mm_end_pa);
			bool separated_va = (end_va < mm->base_va) ||
				(base_va > mm_end_va);

			assert(separated_va && separated_pa);
		}
	}

	mm = mmap; /* Restore pointer to the start of the array */

#endif /* ENABLE_ASSERTIONS */

	/* Find correct place in mmap to insert new region */
	while ((mm->base_va < base_va) && (mm->size != 0U))
		++mm;

	/*
	 * If a section is contained inside another one with the same base
	 * address, it must be placed after the one it is contained in:
	 *
	 * 1st |-----------------------|
	 * 2nd |------------|
	 * 3rd |------|
	 *
	 * This is required for mmap_region_attr() to get the attributes of the
	 * small region correctly.
	 */
	while ((mm->base_va == base_va) && (mm->size > size))
		++mm;

	/* Make room for new region by moving other regions up by one place */
	(void)memmove(mm + 1, mm, (uintptr_t)mm_last - (uintptr_t)mm);

	/* Check we haven't lost the empty sentinal from the end of the array */
	assert(mm_last->size == 0U);

	mm->base_pa = base_pa;
	mm->base_va = base_va;
	mm->size = size;
	mm->attr = attr;

	if (end_pa > xlat_max_pa)
		xlat_max_pa = end_pa;
	if (end_va > xlat_max_va)
		xlat_max_va = end_va;
}

void mmap_add(const mmap_region_t *mm)
{
	const mmap_region_t *mm_cursor = mm;

	while ((mm_cursor->size != 0U) || (mm_cursor->attr != 0U)) {
		mmap_add_region(mm_cursor->base_pa, mm_cursor->base_va,
				mm_cursor->size, mm_cursor->attr);
		mm_cursor++;
	}
}

static uint64_t mmap_desc(unsigned int attr, unsigned long long addr_pa,
			  unsigned int level)
{
	uint64_t desc;
	int mem_type;

	/* Make sure that the granularity is fine enough to map this address. */
	assert((addr_pa & XLAT_BLOCK_MASK(level)) == 0U);

	desc = addr_pa;
	/*
	 * There are different translation table descriptors for level 3 and the
	 * rest.
	 */
	desc |= (level == XLAT_TABLE_LEVEL_MAX) ? PAGE_DESC : BLOCK_DESC;
	desc |= ((attr & MT_NS) != 0U) ? LOWER_ATTRS(NS) : 0U;
	desc |= ((attr & MT_RW) != 0U) ? LOWER_ATTRS(AP_RW) : LOWER_ATTRS(AP_RO);
	/*
	 * Always set the access flag, as this library assumes access flag
	 * faults aren't managed.
	 */
	desc |= LOWER_ATTRS(ACCESS_FLAG);
	desc |= ap1_mask;

	/*
	 * Deduce shareability domain and executability of the memory region
	 * from the memory type.
	 *
	 * Data accesses to device memory and non-cacheable normal memory are
	 * coherent for all observers in the system, and correspondingly are
	 * always treated as being Outer Shareable. Therefore, for these 2 types
	 * of memory, it is not strictly needed to set the shareability field
	 * in the translation tables.
	 */
	mem_type = MT_TYPE(attr);
	if (mem_type == MT_DEVICE) {
		desc |= LOWER_ATTRS(ATTR_DEVICE_INDEX | OSH);
		/*
		 * Always map device memory as execute-never.
		 * This is to avoid the possibility of a speculative instruction
		 * fetch, which could be an issue if this memory region
		 * corresponds to a read-sensitive peripheral.
		 */
		desc |= execute_never_mask;

	} else { /* Normal memory */
		/*
		 * Always map read-write normal memory as execute-never.
		 * This library assumes that it is used by software that does
		 * not self-modify its code, therefore R/W memory is reserved
		 * for data storage, which must not be executable.
		 *
		 * Note that setting the XN bit here is for consistency only.
		 * The function that enables the MMU sets the SCTLR_ELx.WXN bit,
		 * which makes any writable memory region to be treated as
		 * execute-never, regardless of the value of the XN bit in the
		 * translation table.
		 *
		 * For read-only memory, rely on the MT_EXECUTE/MT_EXECUTE_NEVER
		 * attribute to figure out the value of the XN bit.
		 */
		if (((attr & MT_RW) != 0U) || ((attr & MT_EXECUTE_NEVER) != 0U)) {
			desc |= execute_never_mask;
		}

		if (mem_type == MT_MEMORY) {
			desc |= LOWER_ATTRS(ATTR_IWBWA_OWBWA_NTR_INDEX | ISH);
		} else {
			assert(mem_type == MT_NON_CACHEABLE);
			desc |= LOWER_ATTRS(ATTR_NON_CACHEABLE_INDEX | OSH);
		}
	}

	debug_print((mem_type == MT_MEMORY) ? "MEM" :
		((mem_type == MT_NON_CACHEABLE) ? "NC" : "DEV"));
	debug_print(((attr & MT_RW) != 0U) ? "-RW" : "-RO");
	debug_print(((attr & MT_NS) != 0U) ? "-NS" : "-S");
	debug_print(((attr & MT_EXECUTE_NEVER) != 0U) ? "-XN" : "-EXEC");
	return desc;
}

/*
 * Look for the innermost region that contains the area at `base_va` with size
 * `size`. Populate *attr with the attributes of this region.
 *
 * On success, this function returns 0.
 * If there are partial overlaps (meaning that a smaller size is needed) or if
 * the region can't be found in the given area, it returns MT_UNKNOWN. In this
 * case the value pointed by attr should be ignored by the caller.
 */
static unsigned int mmap_region_attr(const mmap_region_t *mm, uintptr_t base_va,
				     size_t size, unsigned int *attr)
{
	/* Don't assume that the area is contained in the first region */
	unsigned int ret = MT_UNKNOWN;

	/*
	 * Get attributes from last (innermost) region that contains the
	 * requested area. Don't stop as soon as one region doesn't contain it
	 * because there may be other internal regions that contain this area:
	 *
	 * |-----------------------------1-----------------------------|
	 * |----2----|     |-------3-------|    |----5----|
	 *                   |--4--|
	 *
	 *                   |---| <- Area we want the attributes of.
	 *
	 * In this example, the area is contained in regions 1, 3 and 4 but not
	 * in region 2. The loop shouldn't stop at region 2 as inner regions
	 * have priority over outer regions, it should stop at region 5.
	 */
	for ( ; ; ++mm) {

		if (mm->size == 0U)
			return ret; /* Reached end of list */

		if (mm->base_va > (base_va + size - 1U))
			return ret; /* Next region is after area so end */

		if ((mm->base_va + mm->size - 1U) < base_va)
			continue; /* Next region has already been overtaken */

		if ((ret == 0U) && (mm->attr == *attr))
			continue; /* Region doesn't override attribs so skip */

		if ((mm->base_va > base_va) ||
			((mm->base_va + mm->size - 1U) < (base_va + size - 1U)))
			return MT_UNKNOWN; /* Region doesn't fully cover area */

		*attr = mm->attr;
		ret = 0U;
	}
	return ret;
}

static mmap_region_t *init_xlation_table_inner(mmap_region_t *mm,
					uintptr_t base_va,
					uint64_t *table,
					unsigned int level)
{
	assert((level >= XLAT_TABLE_LEVEL_MIN) &&
	       (level <= XLAT_TABLE_LEVEL_MAX));

	unsigned int level_size_shift =
		       L0_XLAT_ADDRESS_SHIFT - level * XLAT_TABLE_ENTRIES_SHIFT;
	u_register_t level_size = (u_register_t)1 << level_size_shift;
	u_register_t level_index_mask =
		((u_register_t)XLAT_TABLE_ENTRIES_MASK) << level_size_shift;

	debug_print("New xlat table:\n");

	do  {
		uint64_t desc = UNSET_DESC;

		if (mm->size == 0U) {
			/* Done mapping regions; finish zeroing the table */
			desc = INVALID_DESC;
		} else if ((mm->base_va + mm->size - 1U) < base_va) {
			/* This area is after the region so get next region */
			++mm;
			continue;
		}

		debug_print("%s VA:%p size:0x%llx ", get_level_spacer(level),
			(void *)base_va, (unsigned long long)level_size);

		if (mm->base_va > (base_va + level_size - 1U)) {
			/* Next region is after this area. Nothing to map yet */
			desc = INVALID_DESC;
		/* Make sure that the current level allows block descriptors */
		} else if (level >= XLAT_BLOCK_LEVEL_MIN) {
			/*
			 * Try to get attributes of this area. It will fail if
			 * there are partially overlapping regions. On success,
			 * it will return the innermost region's attributes.
			 */
			unsigned int attr;
			unsigned int r = mmap_region_attr(mm, base_va,
							  level_size, &attr);

			if (r == 0U) {
				desc = mmap_desc(attr,
					base_va - mm->base_va + mm->base_pa,
					level);
			}
		}

		if (desc == UNSET_DESC) {
			/* Area not covered by a region so need finer table */
			uint64_t *new_table = xlat_tables[next_xlat];

			next_xlat++;
			assert(next_xlat <= MAX_XLAT_TABLES);
			desc = TABLE_DESC | (uintptr_t)new_table;

			/* Recurse to fill in new table */
			mm = init_xlation_table_inner(mm, base_va,
						new_table, level + 1U);
		}

		debug_print("\n");

		*table++ = desc;
		base_va += level_size;
	} while ((base_va & level_index_mask) &&
		 ((base_va - 1U) < (PLAT_VIRT_ADDR_SPACE_SIZE - 1U)));

	return mm;
}

void init_xlation_table(uintptr_t base_va, uint64_t *table,
			unsigned int level, uintptr_t *max_va,
			unsigned long long *max_pa)
{
	unsigned int el = xlat_arch_current_el();

	execute_never_mask = xlat_arch_get_xn_desc(el);

	if (el == 3U) {
		ap1_mask = LOWER_ATTRS(AP_ONE_VA_RANGE_RES1);
	} else {
		assert(el == 1U);
		ap1_mask = 0ULL;
	}

	init_xlation_table_inner(mmap, base_va, table, level);
	*max_va = xlat_max_va;
	*max_pa = xlat_max_pa;
}