1 /*
2  * Copyright (c) 2017-2021, 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 <inttypes.h>
10 #include <stdbool.h>
11 #include <stdint.h>
12 #include <stdio.h>
13 
14 #include <platform_def.h>
15 
16 #include <arch_helpers.h>
17 #include <common/debug.h>
18 #include <lib/utils_def.h>
19 #include <lib/xlat_tables/xlat_tables_defs.h>
20 #include <lib/xlat_tables/xlat_tables_v2.h>
21 
22 #include "xlat_tables_private.h"
23 
24 #if LOG_LEVEL < LOG_LEVEL_VERBOSE
25 
xlat_mmap_print(__unused const mmap_region_t * mmap)26 void xlat_mmap_print(__unused const mmap_region_t *mmap)
27 {
28 	/* Empty */
29 }
30 
xlat_tables_print(__unused xlat_ctx_t * ctx)31 void xlat_tables_print(__unused xlat_ctx_t *ctx)
32 {
33 	/* Empty */
34 }
35 
36 #else /* if LOG_LEVEL >= LOG_LEVEL_VERBOSE */
37 
xlat_mmap_print(const mmap_region_t * mmap)38 void xlat_mmap_print(const mmap_region_t *mmap)
39 {
40 	printf("mmap:\n");
41 	const mmap_region_t *mm = mmap;
42 
43 	while (mm->size != 0U) {
44 		printf(" VA:0x%lx  PA:0x%llx  size:0x%zx  attr:0x%x  granularity:0x%zx\n",
45 		       mm->base_va, mm->base_pa, mm->size, mm->attr,
46 		       mm->granularity);
47 		++mm;
48 	};
49 	printf("\n");
50 }
51 
52 /* Print the attributes of the specified block descriptor. */
xlat_desc_print(const xlat_ctx_t * ctx,uint64_t desc)53 static void xlat_desc_print(const xlat_ctx_t *ctx, uint64_t desc)
54 {
55 	uint64_t mem_type_index = ATTR_INDEX_GET(desc);
56 	int xlat_regime = ctx->xlat_regime;
57 
58 	if (mem_type_index == ATTR_IWBWA_OWBWA_NTR_INDEX) {
59 		printf("MEM");
60 	} else if (mem_type_index == ATTR_NON_CACHEABLE_INDEX) {
61 		printf("NC");
62 	} else {
63 		assert(mem_type_index == ATTR_DEVICE_INDEX);
64 		printf("DEV");
65 	}
66 
67 	if ((xlat_regime == EL3_REGIME) || (xlat_regime == EL2_REGIME)) {
68 		/* For EL3 and EL2 only check the AP[2] and XN bits. */
69 		printf(((desc & LOWER_ATTRS(AP_RO)) != 0ULL) ? "-RO" : "-RW");
70 		printf(((desc & UPPER_ATTRS(XN)) != 0ULL) ? "-XN" : "-EXEC");
71 	} else {
72 		assert(xlat_regime == EL1_EL0_REGIME);
73 		/*
74 		 * For EL0 and EL1:
75 		 * - In AArch64 PXN and UXN can be set independently but in
76 		 *   AArch32 there is no UXN (XN affects both privilege levels).
77 		 *   For consistency, we set them simultaneously in both cases.
78 		 * - RO and RW permissions must be the same in EL1 and EL0. If
79 		 *   EL0 can access that memory region, so can EL1, with the
80 		 *   same permissions.
81 		 */
82 #if ENABLE_ASSERTIONS
83 		uint64_t xn_mask = xlat_arch_regime_get_xn_desc(EL1_EL0_REGIME);
84 		uint64_t xn_perm = desc & xn_mask;
85 
86 		assert((xn_perm == xn_mask) || (xn_perm == 0ULL));
87 #endif
88 		printf(((desc & LOWER_ATTRS(AP_RO)) != 0ULL) ? "-RO" : "-RW");
89 		/* Only check one of PXN and UXN, the other one is the same. */
90 		printf(((desc & UPPER_ATTRS(PXN)) != 0ULL) ? "-XN" : "-EXEC");
91 		/*
92 		 * Privileged regions can only be accessed from EL1, user
93 		 * regions can be accessed from EL1 and EL0.
94 		 */
95 		printf(((desc & LOWER_ATTRS(AP_ACCESS_UNPRIVILEGED)) != 0ULL)
96 			  ? "-USER" : "-PRIV");
97 	}
98 
99 #if ENABLE_RME
100 	switch (desc & LOWER_ATTRS(EL3_S1_NSE | NS)) {
101 	case 0ULL:
102 		printf("-S");
103 		break;
104 	case LOWER_ATTRS(NS):
105 		printf("-NS");
106 		break;
107 	case LOWER_ATTRS(EL3_S1_NSE):
108 		printf("-RT");
109 		break;
110 	default: /* LOWER_ATTRS(EL3_S1_NSE | NS) */
111 		printf("-RL");
112 	}
113 #else
114 	printf(((LOWER_ATTRS(NS) & desc) != 0ULL) ? "-NS" : "-S");
115 #endif
116 
117 #ifdef __aarch64__
118 	/* Check Guarded Page bit */
119 	if ((desc & GP) != 0ULL) {
120 		printf("-GP");
121 	}
122 #endif
123 }
124 
125 static const char * const level_spacers[] = {
126 	"[LV0] ",
127 	"  [LV1] ",
128 	"    [LV2] ",
129 	"      [LV3] "
130 };
131 
132 static const char *invalid_descriptors_ommited =
133 		"%s(%d invalid descriptors omitted)\n";
134 
135 /*
136  * Recursive function that reads the translation tables passed as an argument
137  * and prints their status.
138  */
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)139 static void xlat_tables_print_internal(xlat_ctx_t *ctx, uintptr_t table_base_va,
140 		const uint64_t *table_base, unsigned int table_entries,
141 		unsigned int level)
142 {
143 	assert(level <= XLAT_TABLE_LEVEL_MAX);
144 
145 	uint64_t desc;
146 	uintptr_t table_idx_va = table_base_va;
147 	unsigned int table_idx = 0U;
148 	size_t level_size = XLAT_BLOCK_SIZE(level);
149 
150 	/*
151 	 * Keep track of how many invalid descriptors are counted in a row.
152 	 * Whenever multiple invalid descriptors are found, only the first one
153 	 * is printed, and a line is added to inform about how many descriptors
154 	 * have been omitted.
155 	 */
156 	int invalid_row_count = 0;
157 
158 	while (table_idx < table_entries) {
159 
160 		desc = table_base[table_idx];
161 
162 		if ((desc & DESC_MASK) == INVALID_DESC) {
163 
164 			if (invalid_row_count == 0) {
165 				printf("%sVA:0x%lx size:0x%zx\n",
166 				       level_spacers[level],
167 				       table_idx_va, level_size);
168 			}
169 			invalid_row_count++;
170 
171 		} else {
172 
173 			if (invalid_row_count > 1) {
174 				printf(invalid_descriptors_ommited,
175 				       level_spacers[level],
176 				       invalid_row_count - 1);
177 			}
178 			invalid_row_count = 0;
179 
180 			/*
181 			 * Check if this is a table or a block. Tables are only
182 			 * allowed in levels other than 3, but DESC_PAGE has the
183 			 * same value as DESC_TABLE, so we need to check.
184 			 */
185 			if (((desc & DESC_MASK) == TABLE_DESC) &&
186 					(level < XLAT_TABLE_LEVEL_MAX)) {
187 				/*
188 				 * Do not print any PA for a table descriptor,
189 				 * as it doesn't directly map physical memory
190 				 * but instead points to the next translation
191 				 * table in the translation table walk.
192 				 */
193 				printf("%sVA:0x%lx size:0x%zx\n",
194 				       level_spacers[level],
195 				       table_idx_va, level_size);
196 
197 				uintptr_t addr_inner = desc & TABLE_ADDR_MASK;
198 
199 				xlat_tables_print_internal(ctx, table_idx_va,
200 					(uint64_t *)addr_inner,
201 					XLAT_TABLE_ENTRIES, level + 1U);
202 			} else {
203 				printf("%sVA:0x%lx PA:0x%" PRIx64 " size:0x%zx ",
204 				       level_spacers[level], table_idx_va,
205 				       (uint64_t)(desc & TABLE_ADDR_MASK),
206 				       level_size);
207 				xlat_desc_print(ctx, desc);
208 				printf("\n");
209 			}
210 		}
211 
212 		table_idx++;
213 		table_idx_va += level_size;
214 	}
215 
216 	if (invalid_row_count > 1) {
217 		printf(invalid_descriptors_ommited,
218 		       level_spacers[level], invalid_row_count - 1);
219 	}
220 }
221 
xlat_tables_print(xlat_ctx_t * ctx)222 void xlat_tables_print(xlat_ctx_t *ctx)
223 {
224 	const char *xlat_regime_str;
225 	int used_page_tables;
226 
227 	if (ctx->xlat_regime == EL1_EL0_REGIME) {
228 		xlat_regime_str = "1&0";
229 	} else if (ctx->xlat_regime == EL2_REGIME) {
230 		xlat_regime_str = "2";
231 	} else {
232 		assert(ctx->xlat_regime == EL3_REGIME);
233 		xlat_regime_str = "3";
234 	}
235 	VERBOSE("Translation tables state:\n");
236 	VERBOSE("  Xlat regime:     EL%s\n", xlat_regime_str);
237 	VERBOSE("  Max allowed PA:  0x%llx\n", ctx->pa_max_address);
238 	VERBOSE("  Max allowed VA:  0x%lx\n", ctx->va_max_address);
239 	VERBOSE("  Max mapped PA:   0x%llx\n", ctx->max_pa);
240 	VERBOSE("  Max mapped VA:   0x%lx\n", ctx->max_va);
241 
242 	VERBOSE("  Initial lookup level: %u\n", ctx->base_level);
243 	VERBOSE("  Entries @initial lookup level: %u\n",
244 		ctx->base_table_entries);
245 
246 #if PLAT_XLAT_TABLES_DYNAMIC
247 	used_page_tables = 0;
248 	for (int i = 0; i < ctx->tables_num; ++i) {
249 		if (ctx->tables_mapped_regions[i] != 0)
250 			++used_page_tables;
251 	}
252 #else
253 	used_page_tables = ctx->next_table;
254 #endif
255 	VERBOSE("  Used %d sub-tables out of %d (spare: %d)\n",
256 		used_page_tables, ctx->tables_num,
257 		ctx->tables_num - used_page_tables);
258 
259 	xlat_tables_print_internal(ctx, 0U, ctx->base_table,
260 				   ctx->base_table_entries, ctx->base_level);
261 }
262 
263 #endif /* LOG_LEVEL >= LOG_LEVEL_VERBOSE */
264 
265 /*
266  * Do a translation table walk to find the block or page descriptor that maps
267  * virtual_addr.
268  *
269  * On success, return the address of the descriptor within the translation
270  * table. Its lookup level is stored in '*out_level'.
271  * On error, return NULL.
272  *
273  * xlat_table_base
274  *   Base address for the initial lookup level.
275  * xlat_table_base_entries
276  *   Number of entries in the translation table for the initial lookup level.
277  * virt_addr_space_size
278  *   Size in bytes of the virtual address space.
279  */
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)280 static uint64_t *find_xlat_table_entry(uintptr_t virtual_addr,
281 				       void *xlat_table_base,
282 				       unsigned int xlat_table_base_entries,
283 				       unsigned long long virt_addr_space_size,
284 				       unsigned int *out_level)
285 {
286 	unsigned int start_level;
287 	uint64_t *table;
288 	unsigned int entries;
289 
290 	start_level = GET_XLAT_TABLE_LEVEL_BASE(virt_addr_space_size);
291 
292 	table = xlat_table_base;
293 	entries = xlat_table_base_entries;
294 
295 	for (unsigned int level = start_level;
296 	     level <= XLAT_TABLE_LEVEL_MAX;
297 	     ++level) {
298 		uint64_t idx, desc, desc_type;
299 
300 		idx = XLAT_TABLE_IDX(virtual_addr, level);
301 		if (idx >= entries) {
302 			WARN("Missing xlat table entry at address 0x%lx\n",
303 			     virtual_addr);
304 			return NULL;
305 		}
306 
307 		desc = table[idx];
308 		desc_type = desc & DESC_MASK;
309 
310 		if (desc_type == INVALID_DESC) {
311 			VERBOSE("Invalid entry (memory not mapped)\n");
312 			return NULL;
313 		}
314 
315 		if (level == XLAT_TABLE_LEVEL_MAX) {
316 			/*
317 			 * Only page descriptors allowed at the final lookup
318 			 * level.
319 			 */
320 			assert(desc_type == PAGE_DESC);
321 			*out_level = level;
322 			return &table[idx];
323 		}
324 
325 		if (desc_type == BLOCK_DESC) {
326 			*out_level = level;
327 			return &table[idx];
328 		}
329 
330 		assert(desc_type == TABLE_DESC);
331 		table = (uint64_t *)(uintptr_t)(desc & TABLE_ADDR_MASK);
332 		entries = XLAT_TABLE_ENTRIES;
333 	}
334 
335 	/*
336 	 * This shouldn't be reached, the translation table walk should end at
337 	 * most at level XLAT_TABLE_LEVEL_MAX and return from inside the loop.
338 	 */
339 	assert(false);
340 
341 	return NULL;
342 }
343 
344 
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)345 static int xlat_get_mem_attributes_internal(const xlat_ctx_t *ctx,
346 		uintptr_t base_va, uint32_t *attributes, uint64_t **table_entry,
347 		unsigned long long *addr_pa, unsigned int *table_level)
348 {
349 	uint64_t *entry;
350 	uint64_t desc;
351 	unsigned int level;
352 	unsigned long long virt_addr_space_size;
353 
354 	/*
355 	 * Sanity-check arguments.
356 	 */
357 	assert(ctx != NULL);
358 	assert(ctx->initialized);
359 	assert((ctx->xlat_regime == EL1_EL0_REGIME) ||
360 	       (ctx->xlat_regime == EL2_REGIME) ||
361 	       (ctx->xlat_regime == EL3_REGIME));
362 
363 	virt_addr_space_size = (unsigned long long)ctx->va_max_address + 1ULL;
364 	assert(virt_addr_space_size > 0U);
365 
366 	entry = find_xlat_table_entry(base_va,
367 				ctx->base_table,
368 				ctx->base_table_entries,
369 				virt_addr_space_size,
370 				&level);
371 	if (entry == NULL) {
372 		WARN("Address 0x%lx is not mapped.\n", base_va);
373 		return -EINVAL;
374 	}
375 
376 	if (addr_pa != NULL) {
377 		*addr_pa = *entry & TABLE_ADDR_MASK;
378 	}
379 
380 	if (table_entry != NULL) {
381 		*table_entry = entry;
382 	}
383 
384 	if (table_level != NULL) {
385 		*table_level = level;
386 	}
387 
388 	desc = *entry;
389 
390 #if LOG_LEVEL >= LOG_LEVEL_VERBOSE
391 	VERBOSE("Attributes: ");
392 	xlat_desc_print(ctx, desc);
393 	printf("\n");
394 #endif /* LOG_LEVEL >= LOG_LEVEL_VERBOSE */
395 
396 	assert(attributes != NULL);
397 	*attributes = 0U;
398 
399 	uint64_t attr_index = (desc >> ATTR_INDEX_SHIFT) & ATTR_INDEX_MASK;
400 
401 	if (attr_index == ATTR_IWBWA_OWBWA_NTR_INDEX) {
402 		*attributes |= MT_MEMORY;
403 	} else if (attr_index == ATTR_NON_CACHEABLE_INDEX) {
404 		*attributes |= MT_NON_CACHEABLE;
405 	} else {
406 		assert(attr_index == ATTR_DEVICE_INDEX);
407 		*attributes |= MT_DEVICE;
408 	}
409 
410 	uint64_t ap2_bit = (desc >> AP2_SHIFT) & 1U;
411 
412 	if (ap2_bit == AP2_RW)
413 		*attributes |= MT_RW;
414 
415 	if (ctx->xlat_regime == EL1_EL0_REGIME) {
416 		uint64_t ap1_bit = (desc >> AP1_SHIFT) & 1U;
417 
418 		if (ap1_bit == AP1_ACCESS_UNPRIVILEGED)
419 			*attributes |= MT_USER;
420 	}
421 
422 	uint64_t ns_bit = (desc >> NS_SHIFT) & 1U;
423 
424 	if (ns_bit == 1U)
425 		*attributes |= MT_NS;
426 
427 	uint64_t xn_mask = xlat_arch_regime_get_xn_desc(ctx->xlat_regime);
428 
429 	if ((desc & xn_mask) == xn_mask) {
430 		*attributes |= MT_EXECUTE_NEVER;
431 	} else {
432 		assert((desc & xn_mask) == 0U);
433 	}
434 
435 	return 0;
436 }
437 
438 
xlat_get_mem_attributes_ctx(const xlat_ctx_t * ctx,uintptr_t base_va,uint32_t * attr)439 int xlat_get_mem_attributes_ctx(const xlat_ctx_t *ctx, uintptr_t base_va,
440 				uint32_t *attr)
441 {
442 	return xlat_get_mem_attributes_internal(ctx, base_va, attr,
443 				NULL, NULL, NULL);
444 }
445 
446 
xlat_change_mem_attributes_ctx(const xlat_ctx_t * ctx,uintptr_t base_va,size_t size,uint32_t attr)447 int xlat_change_mem_attributes_ctx(const xlat_ctx_t *ctx, uintptr_t base_va,
448 				   size_t size, uint32_t attr)
449 {
450 	/* Note: This implementation isn't optimized. */
451 
452 	assert(ctx != NULL);
453 	assert(ctx->initialized);
454 
455 	unsigned long long virt_addr_space_size =
456 		(unsigned long long)ctx->va_max_address + 1U;
457 	assert(virt_addr_space_size > 0U);
458 
459 	if (!IS_PAGE_ALIGNED(base_va)) {
460 		WARN("%s: Address 0x%lx is not aligned on a page boundary.\n",
461 		     __func__, base_va);
462 		return -EINVAL;
463 	}
464 
465 	if (size == 0U) {
466 		WARN("%s: Size is 0.\n", __func__);
467 		return -EINVAL;
468 	}
469 
470 	if ((size % PAGE_SIZE) != 0U) {
471 		WARN("%s: Size 0x%zx is not a multiple of a page size.\n",
472 		     __func__, size);
473 		return -EINVAL;
474 	}
475 
476 	if (((attr & MT_EXECUTE_NEVER) == 0U) && ((attr & MT_RW) != 0U)) {
477 		WARN("%s: Mapping memory as read-write and executable not allowed.\n",
478 		     __func__);
479 		return -EINVAL;
480 	}
481 
482 	size_t pages_count = size / PAGE_SIZE;
483 
484 	VERBOSE("Changing memory attributes of %zu pages starting from address 0x%lx...\n",
485 		pages_count, base_va);
486 
487 	uintptr_t base_va_original = base_va;
488 
489 	/*
490 	 * Sanity checks.
491 	 */
492 	for (unsigned int i = 0U; i < pages_count; ++i) {
493 		const uint64_t *entry;
494 		uint64_t desc, attr_index;
495 		unsigned int level;
496 
497 		entry = find_xlat_table_entry(base_va,
498 					      ctx->base_table,
499 					      ctx->base_table_entries,
500 					      virt_addr_space_size,
501 					      &level);
502 		if (entry == NULL) {
503 			WARN("Address 0x%lx is not mapped.\n", base_va);
504 			return -EINVAL;
505 		}
506 
507 		desc = *entry;
508 
509 		/*
510 		 * Check that all the required pages are mapped at page
511 		 * granularity.
512 		 */
513 		if (((desc & DESC_MASK) != PAGE_DESC) ||
514 			(level != XLAT_TABLE_LEVEL_MAX)) {
515 			WARN("Address 0x%lx is not mapped at the right granularity.\n",
516 			     base_va);
517 			WARN("Granularity is 0x%lx, should be 0x%lx.\n",
518 			     XLAT_BLOCK_SIZE(level), PAGE_SIZE);
519 			return -EINVAL;
520 		}
521 
522 		/*
523 		 * If the region type is device, it shouldn't be executable.
524 		 */
525 		attr_index = (desc >> ATTR_INDEX_SHIFT) & ATTR_INDEX_MASK;
526 		if (attr_index == ATTR_DEVICE_INDEX) {
527 			if ((attr & MT_EXECUTE_NEVER) == 0U) {
528 				WARN("Setting device memory as executable at address 0x%lx.",
529 				     base_va);
530 				return -EINVAL;
531 			}
532 		}
533 
534 		base_va += PAGE_SIZE;
535 	}
536 
537 	/* Restore original value. */
538 	base_va = base_va_original;
539 
540 	for (unsigned int i = 0U; i < pages_count; ++i) {
541 
542 		uint32_t old_attr = 0U, new_attr;
543 		uint64_t *entry = NULL;
544 		unsigned int level = 0U;
545 		unsigned long long addr_pa = 0ULL;
546 
547 		(void) xlat_get_mem_attributes_internal(ctx, base_va, &old_attr,
548 					    &entry, &addr_pa, &level);
549 
550 		/*
551 		 * From attr, only MT_RO/MT_RW, MT_EXECUTE/MT_EXECUTE_NEVER and
552 		 * MT_USER/MT_PRIVILEGED are taken into account. Any other
553 		 * information is ignored.
554 		 */
555 
556 		/* Clean the old attributes so that they can be rebuilt. */
557 		new_attr = old_attr & ~(MT_RW | MT_EXECUTE_NEVER | MT_USER);
558 
559 		/*
560 		 * Update attributes, but filter out the ones this function
561 		 * isn't allowed to change.
562 		 */
563 		new_attr |= attr & (MT_RW | MT_EXECUTE_NEVER | MT_USER);
564 
565 		/*
566 		 * The break-before-make sequence requires writing an invalid
567 		 * descriptor and making sure that the system sees the change
568 		 * before writing the new descriptor.
569 		 */
570 		*entry = INVALID_DESC;
571 #if !HW_ASSISTED_COHERENCY
572 		dccvac((uintptr_t)entry);
573 #endif
574 		/* Invalidate any cached copy of this mapping in the TLBs. */
575 		xlat_arch_tlbi_va(base_va, ctx->xlat_regime);
576 
577 		/* Ensure completion of the invalidation. */
578 		xlat_arch_tlbi_va_sync();
579 
580 		/* Write new descriptor */
581 		*entry = xlat_desc(ctx, new_attr, addr_pa, level);
582 #if !HW_ASSISTED_COHERENCY
583 		dccvac((uintptr_t)entry);
584 #endif
585 		base_va += PAGE_SIZE;
586 	}
587 
588 	/* Ensure that the last descriptor writen is seen by the system. */
589 	dsbish();
590 
591 	return 0;
592 }
593