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