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1 /*
2  * Copyright (c) 2017-2020, ARM Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #include <assert.h>
8 #include <errno.h>
9 #include <stdbool.h>
10 #include <stdint.h>
11 #include <stdio.h>
12 
13 #include <platform_def.h>
14 
15 #include <arch_helpers.h>
16 #include <common/debug.h>
17 #include <lib/utils_def.h>
18 #include <lib/xlat_tables/xlat_tables_defs.h>
19 #include <lib/xlat_tables/xlat_tables_v2.h>
20 
21 #include "xlat_tables_private.h"
22 
23 #if LOG_LEVEL < LOG_LEVEL_VERBOSE
24 
xlat_mmap_print(__unused const mmap_region_t * mmap)25 void xlat_mmap_print(__unused const mmap_region_t *mmap)
26 {
27 	/* Empty */
28 }
29 
xlat_tables_print(__unused xlat_ctx_t * ctx)30 void xlat_tables_print(__unused xlat_ctx_t *ctx)
31 {
32 	/* Empty */
33 }
34 
35 #else /* if LOG_LEVEL >= LOG_LEVEL_VERBOSE */
36 
xlat_mmap_print(const mmap_region_t * mmap)37 void xlat_mmap_print(const mmap_region_t *mmap)
38 {
39 	printf("mmap:\n");
40 	const mmap_region_t *mm = mmap;
41 
42 	while (mm->size != 0U) {
43 		printf(" VA:0x%lx  PA:0x%llx  size:0x%zx  attr:0x%x  granularity:0x%zx\n",
44 		       mm->base_va, mm->base_pa, mm->size, mm->attr,
45 		       mm->granularity);
46 		++mm;
47 	};
48 	printf("\n");
49 }
50 
51 /* Print the attributes of the specified block descriptor. */
xlat_desc_print(const xlat_ctx_t * ctx,uint64_t desc)52 static void xlat_desc_print(const xlat_ctx_t *ctx, uint64_t desc)
53 {
54 	uint64_t mem_type_index = ATTR_INDEX_GET(desc);
55 	int xlat_regime = ctx->xlat_regime;
56 
57 	if (mem_type_index == ATTR_IWBWA_OWBWA_NTR_INDEX) {
58 		printf("MEM");
59 	} else if (mem_type_index == ATTR_NON_CACHEABLE_INDEX) {
60 		printf("NC");
61 	} else {
62 		assert(mem_type_index == ATTR_DEVICE_INDEX);
63 		printf("DEV");
64 	}
65 
66 	if ((xlat_regime == EL3_REGIME) || (xlat_regime == EL2_REGIME)) {
67 		/* For EL3 and EL2 only check the AP[2] and XN bits. */
68 		printf(((desc & LOWER_ATTRS(AP_RO)) != 0ULL) ? "-RO" : "-RW");
69 		printf(((desc & UPPER_ATTRS(XN)) != 0ULL) ? "-XN" : "-EXEC");
70 	} else {
71 		assert(xlat_regime == EL1_EL0_REGIME);
72 		/*
73 		 * For EL0 and EL1:
74 		 * - In AArch64 PXN and UXN can be set independently but in
75 		 *   AArch32 there is no UXN (XN affects both privilege levels).
76 		 *   For consistency, we set them simultaneously in both cases.
77 		 * - RO and RW permissions must be the same in EL1 and EL0. If
78 		 *   EL0 can access that memory region, so can EL1, with the
79 		 *   same permissions.
80 		 */
81 #if ENABLE_ASSERTIONS
82 		uint64_t xn_mask = xlat_arch_regime_get_xn_desc(EL1_EL0_REGIME);
83 		uint64_t xn_perm = desc & xn_mask;
84 
85 		assert((xn_perm == xn_mask) || (xn_perm == 0ULL));
86 #endif
87 		printf(((desc & LOWER_ATTRS(AP_RO)) != 0ULL) ? "-RO" : "-RW");
88 		/* Only check one of PXN and UXN, the other one is the same. */
89 		printf(((desc & UPPER_ATTRS(PXN)) != 0ULL) ? "-XN" : "-EXEC");
90 		/*
91 		 * Privileged regions can only be accessed from EL1, user
92 		 * regions can be accessed from EL1 and EL0.
93 		 */
94 		printf(((desc & LOWER_ATTRS(AP_ACCESS_UNPRIVILEGED)) != 0ULL)
95 			  ? "-USER" : "-PRIV");
96 	}
97 
98 	printf(((LOWER_ATTRS(NS) & desc) != 0ULL) ? "-NS" : "-S");
99 
100 #ifdef __aarch64__
101 	/* Check Guarded Page bit */
102 	if ((desc & GP) != 0ULL) {
103 		printf("-GP");
104 	}
105 #endif
106 }
107 
108 static const char * const level_spacers[] = {
109 	"[LV0] ",
110 	"  [LV1] ",
111 	"    [LV2] ",
112 	"      [LV3] "
113 };
114 
115 static const char *invalid_descriptors_ommited =
116 		"%s(%d invalid descriptors omitted)\n";
117 
118 /*
119  * Recursive function that reads the translation tables passed as an argument
120  * and prints their status.
121  */
xlat_tables_print_internal(xlat_ctx_t * ctx,uintptr_t table_base_va,const uint64_t * table_base,unsigned int table_entries,unsigned int level)122 static void xlat_tables_print_internal(xlat_ctx_t *ctx, uintptr_t table_base_va,
123 		const uint64_t *table_base, unsigned int table_entries,
124 		unsigned int level)
125 {
126 	assert(level <= XLAT_TABLE_LEVEL_MAX);
127 
128 	uint64_t desc;
129 	uintptr_t table_idx_va = table_base_va;
130 	unsigned int table_idx = 0U;
131 	size_t level_size = XLAT_BLOCK_SIZE(level);
132 
133 	/*
134 	 * Keep track of how many invalid descriptors are counted in a row.
135 	 * Whenever multiple invalid descriptors are found, only the first one
136 	 * is printed, and a line is added to inform about how many descriptors
137 	 * have been omitted.
138 	 */
139 	int invalid_row_count = 0;
140 
141 	while (table_idx < table_entries) {
142 
143 		desc = table_base[table_idx];
144 
145 		if ((desc & DESC_MASK) == INVALID_DESC) {
146 
147 			if (invalid_row_count == 0) {
148 				printf("%sVA:0x%lx size:0x%zx\n",
149 				       level_spacers[level],
150 				       table_idx_va, level_size);
151 			}
152 			invalid_row_count++;
153 
154 		} else {
155 
156 			if (invalid_row_count > 1) {
157 				printf(invalid_descriptors_ommited,
158 				       level_spacers[level],
159 				       invalid_row_count - 1);
160 			}
161 			invalid_row_count = 0;
162 
163 			/*
164 			 * Check if this is a table or a block. Tables are only
165 			 * allowed in levels other than 3, but DESC_PAGE has the
166 			 * same value as DESC_TABLE, so we need to check.
167 			 */
168 			if (((desc & DESC_MASK) == TABLE_DESC) &&
169 					(level < XLAT_TABLE_LEVEL_MAX)) {
170 				/*
171 				 * Do not print any PA for a table descriptor,
172 				 * as it doesn't directly map physical memory
173 				 * but instead points to the next translation
174 				 * table in the translation table walk.
175 				 */
176 				printf("%sVA:0x%lx size:0x%zx\n",
177 				       level_spacers[level],
178 				       table_idx_va, level_size);
179 
180 				uintptr_t addr_inner = desc & TABLE_ADDR_MASK;
181 
182 				xlat_tables_print_internal(ctx, table_idx_va,
183 					(uint64_t *)addr_inner,
184 					XLAT_TABLE_ENTRIES, level + 1U);
185 			} else {
186 				printf("%sVA:0x%lx PA:0x%llx size:0x%zx ",
187 				       level_spacers[level], table_idx_va,
188 				       (uint64_t)(desc & TABLE_ADDR_MASK),
189 				       level_size);
190 				xlat_desc_print(ctx, desc);
191 				printf("\n");
192 			}
193 		}
194 
195 		table_idx++;
196 		table_idx_va += level_size;
197 	}
198 
199 	if (invalid_row_count > 1) {
200 		printf(invalid_descriptors_ommited,
201 		       level_spacers[level], invalid_row_count - 1);
202 	}
203 }
204 
xlat_tables_print(xlat_ctx_t * ctx)205 void xlat_tables_print(xlat_ctx_t *ctx)
206 {
207 	const char *xlat_regime_str;
208 	int used_page_tables;
209 
210 	if (ctx->xlat_regime == EL1_EL0_REGIME) {
211 		xlat_regime_str = "1&0";
212 	} else if (ctx->xlat_regime == EL2_REGIME) {
213 		xlat_regime_str = "2";
214 	} else {
215 		assert(ctx->xlat_regime == EL3_REGIME);
216 		xlat_regime_str = "3";
217 	}
218 	VERBOSE("Translation tables state:\n");
219 	VERBOSE("  Xlat regime:     EL%s\n", xlat_regime_str);
220 	VERBOSE("  Max allowed PA:  0x%llx\n", ctx->pa_max_address);
221 	VERBOSE("  Max allowed VA:  0x%lx\n", ctx->va_max_address);
222 	VERBOSE("  Max mapped PA:   0x%llx\n", ctx->max_pa);
223 	VERBOSE("  Max mapped VA:   0x%lx\n", ctx->max_va);
224 
225 	VERBOSE("  Initial lookup level: %u\n", ctx->base_level);
226 	VERBOSE("  Entries @initial lookup level: %u\n",
227 		ctx->base_table_entries);
228 
229 #if PLAT_XLAT_TABLES_DYNAMIC
230 	used_page_tables = 0;
231 	for (int i = 0; i < ctx->tables_num; ++i) {
232 		if (ctx->tables_mapped_regions[i] != 0)
233 			++used_page_tables;
234 	}
235 #else
236 	used_page_tables = ctx->next_table;
237 #endif
238 	VERBOSE("  Used %d sub-tables out of %d (spare: %d)\n",
239 		used_page_tables, ctx->tables_num,
240 		ctx->tables_num - used_page_tables);
241 
242 	xlat_tables_print_internal(ctx, 0U, ctx->base_table,
243 				   ctx->base_table_entries, ctx->base_level);
244 }
245 
246 #endif /* LOG_LEVEL >= LOG_LEVEL_VERBOSE */
247 
248 /*
249  * Do a translation table walk to find the block or page descriptor that maps
250  * virtual_addr.
251  *
252  * On success, return the address of the descriptor within the translation
253  * table. Its lookup level is stored in '*out_level'.
254  * On error, return NULL.
255  *
256  * xlat_table_base
257  *   Base address for the initial lookup level.
258  * xlat_table_base_entries
259  *   Number of entries in the translation table for the initial lookup level.
260  * virt_addr_space_size
261  *   Size in bytes of the virtual address space.
262  */
find_xlat_table_entry(uintptr_t virtual_addr,void * xlat_table_base,unsigned int xlat_table_base_entries,unsigned long long virt_addr_space_size,unsigned int * out_level)263 static uint64_t *find_xlat_table_entry(uintptr_t virtual_addr,
264 				       void *xlat_table_base,
265 				       unsigned int xlat_table_base_entries,
266 				       unsigned long long virt_addr_space_size,
267 				       unsigned int *out_level)
268 {
269 	unsigned int start_level;
270 	uint64_t *table;
271 	unsigned int entries;
272 
273 	start_level = GET_XLAT_TABLE_LEVEL_BASE(virt_addr_space_size);
274 
275 	table = xlat_table_base;
276 	entries = xlat_table_base_entries;
277 
278 	for (unsigned int level = start_level;
279 	     level <= XLAT_TABLE_LEVEL_MAX;
280 	     ++level) {
281 		uint64_t idx, desc, desc_type;
282 
283 		idx = XLAT_TABLE_IDX(virtual_addr, level);
284 		if (idx >= entries) {
285 			WARN("Missing xlat table entry at address 0x%lx\n",
286 			     virtual_addr);
287 			return NULL;
288 		}
289 
290 		desc = table[idx];
291 		desc_type = desc & DESC_MASK;
292 
293 		if (desc_type == INVALID_DESC) {
294 			VERBOSE("Invalid entry (memory not mapped)\n");
295 			return NULL;
296 		}
297 
298 		if (level == XLAT_TABLE_LEVEL_MAX) {
299 			/*
300 			 * Only page descriptors allowed at the final lookup
301 			 * level.
302 			 */
303 			assert(desc_type == PAGE_DESC);
304 			*out_level = level;
305 			return &table[idx];
306 		}
307 
308 		if (desc_type == BLOCK_DESC) {
309 			*out_level = level;
310 			return &table[idx];
311 		}
312 
313 		assert(desc_type == TABLE_DESC);
314 		table = (uint64_t *)(uintptr_t)(desc & TABLE_ADDR_MASK);
315 		entries = XLAT_TABLE_ENTRIES;
316 	}
317 
318 	/*
319 	 * This shouldn't be reached, the translation table walk should end at
320 	 * most at level XLAT_TABLE_LEVEL_MAX and return from inside the loop.
321 	 */
322 	assert(false);
323 
324 	return NULL;
325 }
326 
327 
xlat_get_mem_attributes_internal(const xlat_ctx_t * ctx,uintptr_t base_va,uint32_t * attributes,uint64_t ** table_entry,unsigned long long * addr_pa,unsigned int * table_level)328 static int xlat_get_mem_attributes_internal(const xlat_ctx_t *ctx,
329 		uintptr_t base_va, uint32_t *attributes, uint64_t **table_entry,
330 		unsigned long long *addr_pa, unsigned int *table_level)
331 {
332 	uint64_t *entry;
333 	uint64_t desc;
334 	unsigned int level;
335 	unsigned long long virt_addr_space_size;
336 
337 	/*
338 	 * Sanity-check arguments.
339 	 */
340 	assert(ctx != NULL);
341 	assert(ctx->initialized);
342 	assert((ctx->xlat_regime == EL1_EL0_REGIME) ||
343 	       (ctx->xlat_regime == EL2_REGIME) ||
344 	       (ctx->xlat_regime == EL3_REGIME));
345 
346 	virt_addr_space_size = (unsigned long long)ctx->va_max_address + 1ULL;
347 	assert(virt_addr_space_size > 0U);
348 
349 	entry = find_xlat_table_entry(base_va,
350 				ctx->base_table,
351 				ctx->base_table_entries,
352 				virt_addr_space_size,
353 				&level);
354 	if (entry == NULL) {
355 		WARN("Address 0x%lx is not mapped.\n", base_va);
356 		return -EINVAL;
357 	}
358 
359 	if (addr_pa != NULL) {
360 		*addr_pa = *entry & TABLE_ADDR_MASK;
361 	}
362 
363 	if (table_entry != NULL) {
364 		*table_entry = entry;
365 	}
366 
367 	if (table_level != NULL) {
368 		*table_level = level;
369 	}
370 
371 	desc = *entry;
372 
373 #if LOG_LEVEL >= LOG_LEVEL_VERBOSE
374 	VERBOSE("Attributes: ");
375 	xlat_desc_print(ctx, desc);
376 	printf("\n");
377 #endif /* LOG_LEVEL >= LOG_LEVEL_VERBOSE */
378 
379 	assert(attributes != NULL);
380 	*attributes = 0U;
381 
382 	uint64_t attr_index = (desc >> ATTR_INDEX_SHIFT) & ATTR_INDEX_MASK;
383 
384 	if (attr_index == ATTR_IWBWA_OWBWA_NTR_INDEX) {
385 		*attributes |= MT_MEMORY;
386 	} else if (attr_index == ATTR_NON_CACHEABLE_INDEX) {
387 		*attributes |= MT_NON_CACHEABLE;
388 	} else {
389 		assert(attr_index == ATTR_DEVICE_INDEX);
390 		*attributes |= MT_DEVICE;
391 	}
392 
393 	uint64_t ap2_bit = (desc >> AP2_SHIFT) & 1U;
394 
395 	if (ap2_bit == AP2_RW)
396 		*attributes |= MT_RW;
397 
398 	if (ctx->xlat_regime == EL1_EL0_REGIME) {
399 		uint64_t ap1_bit = (desc >> AP1_SHIFT) & 1U;
400 
401 		if (ap1_bit == AP1_ACCESS_UNPRIVILEGED)
402 			*attributes |= MT_USER;
403 	}
404 
405 	uint64_t ns_bit = (desc >> NS_SHIFT) & 1U;
406 
407 	if (ns_bit == 1U)
408 		*attributes |= MT_NS;
409 
410 	uint64_t xn_mask = xlat_arch_regime_get_xn_desc(ctx->xlat_regime);
411 
412 	if ((desc & xn_mask) == xn_mask) {
413 		*attributes |= MT_EXECUTE_NEVER;
414 	} else {
415 		assert((desc & xn_mask) == 0U);
416 	}
417 
418 	return 0;
419 }
420 
421 
xlat_get_mem_attributes_ctx(const xlat_ctx_t * ctx,uintptr_t base_va,uint32_t * attr)422 int xlat_get_mem_attributes_ctx(const xlat_ctx_t *ctx, uintptr_t base_va,
423 				uint32_t *attr)
424 {
425 	return xlat_get_mem_attributes_internal(ctx, base_va, attr,
426 				NULL, NULL, NULL);
427 }
428 
429 
xlat_change_mem_attributes_ctx(const xlat_ctx_t * ctx,uintptr_t base_va,size_t size,uint32_t attr)430 int xlat_change_mem_attributes_ctx(const xlat_ctx_t *ctx, uintptr_t base_va,
431 				   size_t size, uint32_t attr)
432 {
433 	/* Note: This implementation isn't optimized. */
434 
435 	assert(ctx != NULL);
436 	assert(ctx->initialized);
437 
438 	unsigned long long virt_addr_space_size =
439 		(unsigned long long)ctx->va_max_address + 1U;
440 	assert(virt_addr_space_size > 0U);
441 
442 	if (!IS_PAGE_ALIGNED(base_va)) {
443 		WARN("%s: Address 0x%lx is not aligned on a page boundary.\n",
444 		     __func__, base_va);
445 		return -EINVAL;
446 	}
447 
448 	if (size == 0U) {
449 		WARN("%s: Size is 0.\n", __func__);
450 		return -EINVAL;
451 	}
452 
453 	if ((size % PAGE_SIZE) != 0U) {
454 		WARN("%s: Size 0x%zx is not a multiple of a page size.\n",
455 		     __func__, size);
456 		return -EINVAL;
457 	}
458 
459 	if (((attr & MT_EXECUTE_NEVER) == 0U) && ((attr & MT_RW) != 0U)) {
460 		WARN("%s: Mapping memory as read-write and executable not allowed.\n",
461 		     __func__);
462 		return -EINVAL;
463 	}
464 
465 	size_t pages_count = size / PAGE_SIZE;
466 
467 	VERBOSE("Changing memory attributes of %zu pages starting from address 0x%lx...\n",
468 		pages_count, base_va);
469 
470 	uintptr_t base_va_original = base_va;
471 
472 	/*
473 	 * Sanity checks.
474 	 */
475 	for (unsigned int i = 0U; i < pages_count; ++i) {
476 		const uint64_t *entry;
477 		uint64_t desc, attr_index;
478 		unsigned int level;
479 
480 		entry = find_xlat_table_entry(base_va,
481 					      ctx->base_table,
482 					      ctx->base_table_entries,
483 					      virt_addr_space_size,
484 					      &level);
485 		if (entry == NULL) {
486 			WARN("Address 0x%lx is not mapped.\n", base_va);
487 			return -EINVAL;
488 		}
489 
490 		desc = *entry;
491 
492 		/*
493 		 * Check that all the required pages are mapped at page
494 		 * granularity.
495 		 */
496 		if (((desc & DESC_MASK) != PAGE_DESC) ||
497 			(level != XLAT_TABLE_LEVEL_MAX)) {
498 			WARN("Address 0x%lx is not mapped at the right granularity.\n",
499 			     base_va);
500 			WARN("Granularity is 0x%lx, should be 0x%lx.\n",
501 			     XLAT_BLOCK_SIZE(level), PAGE_SIZE);
502 			return -EINVAL;
503 		}
504 
505 		/*
506 		 * If the region type is device, it shouldn't be executable.
507 		 */
508 		attr_index = (desc >> ATTR_INDEX_SHIFT) & ATTR_INDEX_MASK;
509 		if (attr_index == ATTR_DEVICE_INDEX) {
510 			if ((attr & MT_EXECUTE_NEVER) == 0U) {
511 				WARN("Setting device memory as executable at address 0x%lx.",
512 				     base_va);
513 				return -EINVAL;
514 			}
515 		}
516 
517 		base_va += PAGE_SIZE;
518 	}
519 
520 	/* Restore original value. */
521 	base_va = base_va_original;
522 
523 	for (unsigned int i = 0U; i < pages_count; ++i) {
524 
525 		uint32_t old_attr = 0U, new_attr;
526 		uint64_t *entry = NULL;
527 		unsigned int level = 0U;
528 		unsigned long long addr_pa = 0ULL;
529 
530 		(void) xlat_get_mem_attributes_internal(ctx, base_va, &old_attr,
531 					    &entry, &addr_pa, &level);
532 
533 		/*
534 		 * From attr, only MT_RO/MT_RW, MT_EXECUTE/MT_EXECUTE_NEVER and
535 		 * MT_USER/MT_PRIVILEGED are taken into account. Any other
536 		 * information is ignored.
537 		 */
538 
539 		/* Clean the old attributes so that they can be rebuilt. */
540 		new_attr = old_attr & ~(MT_RW | MT_EXECUTE_NEVER | MT_USER);
541 
542 		/*
543 		 * Update attributes, but filter out the ones this function
544 		 * isn't allowed to change.
545 		 */
546 		new_attr |= attr & (MT_RW | MT_EXECUTE_NEVER | MT_USER);
547 
548 		/*
549 		 * The break-before-make sequence requires writing an invalid
550 		 * descriptor and making sure that the system sees the change
551 		 * before writing the new descriptor.
552 		 */
553 		*entry = INVALID_DESC;
554 #if !HW_ASSISTED_COHERENCY
555 		dccvac((uintptr_t)entry);
556 #endif
557 		/* Invalidate any cached copy of this mapping in the TLBs. */
558 		xlat_arch_tlbi_va(base_va, ctx->xlat_regime);
559 
560 		/* Ensure completion of the invalidation. */
561 		xlat_arch_tlbi_va_sync();
562 
563 		/* Write new descriptor */
564 		*entry = xlat_desc(ctx, new_attr, addr_pa, level);
565 #if !HW_ASSISTED_COHERENCY
566 		dccvac((uintptr_t)entry);
567 #endif
568 		base_va += PAGE_SIZE;
569 	}
570 
571 	/* Ensure that the last descriptor writen is seen by the system. */
572 	dsbish();
573 
574 	return 0;
575 }
576