xref: /rk3399_ARM-atf/lib/gpt_rme/gpt_rme.c (revision 4ce3e99a336b74611349595ea7fd5ed0277c3eeb)
1 /*
2  * Copyright (c) 2021, Arm Limited. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #include <assert.h>
8 #include <errno.h>
9 #include <limits.h>
10 #include <stdint.h>
11 
12 #include <arch.h>
13 #include <arch_helpers.h>
14 #include <common/debug.h>
15 #include "gpt_rme_private.h"
16 #include <lib/gpt_rme/gpt_rme.h>
17 #include <lib/smccc.h>
18 #include <lib/spinlock.h>
19 #include <lib/xlat_tables/xlat_tables_v2.h>
20 
21 #if !ENABLE_RME
22 #error "ENABLE_RME must be enabled to use the GPT library."
23 #endif
24 
25 /*
26  * Lookup T from PPS
27  *
28  *   PPS    Size    T
29  *   0b000  4GB     32
30  *   0b001  64GB    36
31  *   0b010  1TB     40
32  *   0b011  4TB     42
33  *   0b100  16TB    44
34  *   0b101  256TB   48
35  *   0b110  4PB     52
36  *
37  * See section 15.1.27 of the RME specification.
38  */
39 static const gpt_t_val_e gpt_t_lookup[] = {PPS_4GB_T, PPS_64GB_T,
40 					   PPS_1TB_T, PPS_4TB_T,
41 					   PPS_16TB_T, PPS_256TB_T,
42 					   PPS_4PB_T};
43 
44 /*
45  * Lookup P from PGS
46  *
47  *   PGS    Size    P
48  *   0b00   4KB     12
49  *   0b10   16KB    14
50  *   0b01   64KB    16
51  *
52  * Note that pgs=0b10 is 16KB and pgs=0b01 is 64KB, this is not a typo.
53  *
54  * See section 15.1.27 of the RME specification.
55  */
56 static const gpt_p_val_e gpt_p_lookup[] = {PGS_4KB_P, PGS_64KB_P, PGS_16KB_P};
57 
58 /*
59  * This structure contains GPT configuration data.
60  */
61 typedef struct {
62 	uintptr_t plat_gpt_l0_base;
63 	gpccr_pps_e pps;
64 	gpt_t_val_e t;
65 	gpccr_pgs_e pgs;
66 	gpt_p_val_e p;
67 } gpt_config_t;
68 
69 static gpt_config_t gpt_config;
70 
71 /* These variables are used during initialization of the L1 tables. */
72 static unsigned int gpt_next_l1_tbl_idx;
73 static uintptr_t gpt_l1_tbl;
74 
75 /*
76  * This function checks to see if a GPI value is valid.
77  *
78  * These are valid GPI values.
79  *   GPT_GPI_NO_ACCESS   U(0x0)
80  *   GPT_GPI_SECURE      U(0x8)
81  *   GPT_GPI_NS          U(0x9)
82  *   GPT_GPI_ROOT        U(0xA)
83  *   GPT_GPI_REALM       U(0xB)
84  *   GPT_GPI_ANY         U(0xF)
85  *
86  * Parameters
87  *   gpi		GPI to check for validity.
88  *
89  * Return
90  *   true for a valid GPI, false for an invalid one.
91  */
92 static bool gpt_is_gpi_valid(unsigned int gpi)
93 {
94 	if ((gpi == GPT_GPI_NO_ACCESS) || (gpi == GPT_GPI_ANY) ||
95 	    ((gpi >= GPT_GPI_SECURE) && (gpi <= GPT_GPI_REALM))) {
96 		return true;
97 	} else {
98 		return false;
99 	}
100 }
101 
102 /*
103  * This function checks to see if two PAS regions overlap.
104  *
105  * Parameters
106  *   base_1: base address of first PAS
107  *   size_1: size of first PAS
108  *   base_2: base address of second PAS
109  *   size_2: size of second PAS
110  *
111  * Return
112  *   True if PAS regions overlap, false if they do not.
113  */
114 static bool gpt_check_pas_overlap(uintptr_t base_1, size_t size_1,
115 				  uintptr_t base_2, size_t size_2)
116 {
117 	if (((base_1 + size_1) > base_2) && ((base_2 + size_2) > base_1)) {
118 		return true;
119 	} else {
120 		return false;
121 	}
122 }
123 
124 /*
125  * This helper function checks to see if a PAS region from index 0 to
126  * (pas_idx - 1) occupies the L0 region at index l0_idx in the L0 table.
127  *
128  * Parameters
129  *   l0_idx:      Index of the L0 entry to check
130  *   pas_regions: PAS region array
131  *   pas_idx:     Upper bound of the PAS array index.
132  *
133  * Return
134  *   True if a PAS region occupies the L0 region in question, false if not.
135  */
136 static bool gpt_does_previous_pas_exist_here(unsigned int l0_idx,
137 					     pas_region_t *pas_regions,
138 					     unsigned int pas_idx)
139 {
140 	/* Iterate over PAS regions up to pas_idx. */
141 	for (unsigned int i = 0U; i < pas_idx; i++) {
142 		if (gpt_check_pas_overlap((GPT_L0GPTSZ_ACTUAL_SIZE * l0_idx),
143 		    GPT_L0GPTSZ_ACTUAL_SIZE,
144 		    pas_regions[i].base_pa, pas_regions[i].size)) {
145 			return true;
146 		}
147 	}
148 	return false;
149 }
150 
151 /*
152  * This function iterates over all of the PAS regions and checks them to ensure
153  * proper alignment of base and size, that the GPI is valid, and that no regions
154  * overlap. As a part of the overlap checks, this function checks existing L0
155  * mappings against the new PAS regions in the event that gpt_init_pas_l1_tables
156  * is called multiple times to place L1 tables in different areas of memory. It
157  * also counts the number of L1 tables needed and returns it on success.
158  *
159  * Parameters
160  *   *pas_regions	Pointer to array of PAS region structures.
161  *   pas_region_cnt	Total number of PAS regions in the array.
162  *
163  * Return
164  *   Negative Linux error code in the event of a failure, number of L1 regions
165  *   required when successful.
166  */
167 static int gpt_validate_pas_mappings(pas_region_t *pas_regions,
168 				     unsigned int pas_region_cnt)
169 {
170 	unsigned int idx;
171 	unsigned int l1_cnt = 0U;
172 	unsigned int pas_l1_cnt;
173 	uint64_t *l0_desc = (uint64_t *)gpt_config.plat_gpt_l0_base;
174 
175 	assert(pas_regions != NULL);
176 	assert(pas_region_cnt != 0U);
177 
178 	for (idx = 0U; idx < pas_region_cnt; idx++) {
179 		/* Check for arithmetic overflow in region. */
180 		if ((ULONG_MAX - pas_regions[idx].base_pa) <
181 		    pas_regions[idx].size) {
182 			ERROR("[GPT] Address overflow in PAS[%u]!\n", idx);
183 			return -EOVERFLOW;
184 		}
185 
186 		/* Initial checks for PAS validity. */
187 		if (((pas_regions[idx].base_pa + pas_regions[idx].size) >
188 		    GPT_PPS_ACTUAL_SIZE(gpt_config.t)) ||
189 		    !gpt_is_gpi_valid(GPT_PAS_ATTR_GPI(pas_regions[idx].attrs))) {
190 			ERROR("[GPT] PAS[%u] is invalid!\n", idx);
191 			return -EFAULT;
192 		}
193 
194 		/*
195 		 * Make sure this PAS does not overlap with another one. We
196 		 * start from idx + 1 instead of 0 since prior PAS mappings will
197 		 * have already checked themselves against this one.
198 		 */
199 		for (unsigned int i = idx + 1; i < pas_region_cnt; i++) {
200 			if (gpt_check_pas_overlap(pas_regions[idx].base_pa,
201 			    pas_regions[idx].size,
202 			    pas_regions[i].base_pa,
203 			    pas_regions[i].size)) {
204 				ERROR("[GPT] PAS[%u] overlaps with PAS[%u]\n",
205 					i, idx);
206 				return -EFAULT;
207 			}
208 		}
209 
210 		/*
211 		 * Since this function can be called multiple times with
212 		 * separate L1 tables we need to check the existing L0 mapping
213 		 * to see if this PAS would fall into one that has already been
214 		 * initialized.
215 		 */
216 		for (unsigned int i = GPT_L0_IDX(pas_regions[idx].base_pa);
217 		     i <= GPT_L0_IDX(pas_regions[idx].base_pa + pas_regions[idx].size - 1);
218 		     i++) {
219 			if ((GPT_L0_TYPE(l0_desc[i]) == GPT_L0_TYPE_BLK_DESC) &&
220 			    (GPT_L0_BLKD_GPI(l0_desc[i]) == GPT_GPI_ANY)) {
221 				/* This descriptor is unused so continue. */
222 				continue;
223 			}
224 
225 			/*
226 			 * This descriptor has been initialized in a previous
227 			 * call to this function so cannot be initialized again.
228 			 */
229 			ERROR("[GPT] PAS[%u] overlaps with previous L0[%d]!\n",
230 			      idx, i);
231 			return -EFAULT;
232 		}
233 
234 		/* Check for block mapping (L0) type. */
235 		if (GPT_PAS_ATTR_MAP_TYPE(pas_regions[idx].attrs) ==
236 		    GPT_PAS_ATTR_MAP_TYPE_BLOCK) {
237 			/* Make sure base and size are block-aligned. */
238 			if (!GPT_IS_L0_ALIGNED(pas_regions[idx].base_pa) ||
239 			    !GPT_IS_L0_ALIGNED(pas_regions[idx].size)) {
240 				ERROR("[GPT] PAS[%u] is not block-aligned!\n",
241 				      idx);
242 				return -EFAULT;
243 			}
244 
245 			continue;
246 		}
247 
248 		/* Check for granule mapping (L1) type. */
249 		if (GPT_PAS_ATTR_MAP_TYPE(pas_regions[idx].attrs) ==
250 		    GPT_PAS_ATTR_MAP_TYPE_GRANULE) {
251 			/* Make sure base and size are granule-aligned. */
252 			if (!GPT_IS_L1_ALIGNED(gpt_config.p, pas_regions[idx].base_pa) ||
253 			    !GPT_IS_L1_ALIGNED(gpt_config.p, pas_regions[idx].size)) {
254 				ERROR("[GPT] PAS[%u] is not granule-aligned!\n",
255 				      idx);
256 				return -EFAULT;
257 			}
258 
259 			/* Find how many L1 tables this PAS occupies. */
260 			pas_l1_cnt = (GPT_L0_IDX(pas_regions[idx].base_pa +
261 				     pas_regions[idx].size - 1) -
262 				     GPT_L0_IDX(pas_regions[idx].base_pa) + 1);
263 
264 			/*
265 			 * This creates a situation where, if multiple PAS
266 			 * regions occupy the same table descriptor, we can get
267 			 * an artificially high total L1 table count. The way we
268 			 * handle this is by checking each PAS against those
269 			 * before it in the array, and if they both occupy the
270 			 * same PAS we subtract from pas_l1_cnt and only the
271 			 * first PAS in the array gets to count it.
272 			 */
273 
274 			/*
275 			 * If L1 count is greater than 1 we know the start and
276 			 * end PAs are in different L0 regions so we must check
277 			 * both for overlap against other PAS.
278 			 */
279 			if (pas_l1_cnt > 1) {
280 				if (gpt_does_previous_pas_exist_here(
281 				    GPT_L0_IDX(pas_regions[idx].base_pa +
282 				    pas_regions[idx].size - 1),
283 				    pas_regions, idx)) {
284 					pas_l1_cnt = pas_l1_cnt - 1;
285 				}
286 			}
287 
288 			if (gpt_does_previous_pas_exist_here(
289 			    GPT_L0_IDX(pas_regions[idx].base_pa),
290 			    pas_regions, idx)) {
291 				pas_l1_cnt = pas_l1_cnt - 1;
292 			}
293 
294 			l1_cnt += pas_l1_cnt;
295 			continue;
296 		}
297 
298 		/* If execution reaches this point, mapping type is invalid. */
299 		ERROR("[GPT] PAS[%u] has invalid mapping type 0x%x.\n", idx,
300 		      GPT_PAS_ATTR_MAP_TYPE(pas_regions[idx].attrs));
301 		return -EINVAL;
302 	}
303 
304 	return l1_cnt;
305 }
306 
307 /*
308  * This function validates L0 initialization parameters.
309  *
310  * Parameters
311  *   l0_mem_base	Base address of memory used for L0 tables.
312  *   l1_mem_size	Size of memory available for L0 tables.
313  *
314  * Return
315  *   Negative Linux error code in the event of a failure, 0 for success.
316  */
317 static int gpt_validate_l0_params(gpccr_pps_e pps, uintptr_t l0_mem_base,
318 				  size_t l0_mem_size)
319 {
320 	size_t l0_alignment;
321 
322 	/*
323 	 * Make sure PPS is valid and then store it since macros need this value
324 	 * to work.
325 	 */
326 	if (pps > GPT_PPS_MAX) {
327 		ERROR("[GPT] Invalid PPS: 0x%x\n", pps);
328 		return -EINVAL;
329 	}
330 	gpt_config.pps = pps;
331 	gpt_config.t = gpt_t_lookup[pps];
332 
333 	/* Alignment must be the greater of 4k or l0 table size. */
334 	l0_alignment = PAGE_SIZE_4KB;
335 	if (l0_alignment < GPT_L0_TABLE_SIZE(gpt_config.t)) {
336 		l0_alignment = GPT_L0_TABLE_SIZE(gpt_config.t);
337 	}
338 
339 	/* Check base address. */
340 	if ((l0_mem_base == 0U) || ((l0_mem_base & (l0_alignment - 1)) != 0U)) {
341 		ERROR("[GPT] Invalid L0 base address: 0x%lx\n", l0_mem_base);
342 		return -EFAULT;
343 	}
344 
345 	/* Check size. */
346 	if (l0_mem_size < GPT_L0_TABLE_SIZE(gpt_config.t)) {
347 		ERROR("[GPT] Inadequate L0 memory: need 0x%lx, have 0x%lx)\n",
348 		      GPT_L0_TABLE_SIZE(gpt_config.t),
349 		      l0_mem_size);
350 		return -ENOMEM;
351 	}
352 
353 	return 0;
354 }
355 
356 /*
357  * In the event that L1 tables are needed, this function validates
358  * the L1 table generation parameters.
359  *
360  * Parameters
361  *   l1_mem_base	Base address of memory used for L1 table allocation.
362  *   l1_mem_size	Total size of memory available for L1 tables.
363  *   l1_gpt_cnt		Number of L1 tables needed.
364  *
365  * Return
366  *   Negative Linux error code in the event of a failure, 0 for success.
367  */
368 static int gpt_validate_l1_params(uintptr_t l1_mem_base, size_t l1_mem_size,
369 				  unsigned int l1_gpt_cnt)
370 {
371 	size_t l1_gpt_mem_sz;
372 
373 	/* Check if the granularity is supported */
374 	if (!xlat_arch_is_granule_size_supported(
375 	    GPT_PGS_ACTUAL_SIZE(gpt_config.p))) {
376 		return -EPERM;
377 	}
378 
379 	/* Make sure L1 tables are aligned to their size. */
380 	if ((l1_mem_base & (GPT_L1_TABLE_SIZE(gpt_config.p) - 1)) != 0U) {
381 		ERROR("[GPT] Unaligned L1 GPT base address: 0x%lx\n",
382 		      l1_mem_base);
383 		return -EFAULT;
384 	}
385 
386 	/* Get total memory needed for L1 tables. */
387 	l1_gpt_mem_sz = l1_gpt_cnt * GPT_L1_TABLE_SIZE(gpt_config.p);
388 
389 	/* Check for overflow. */
390 	if ((l1_gpt_mem_sz / GPT_L1_TABLE_SIZE(gpt_config.p)) != l1_gpt_cnt) {
391 		ERROR("[GPT] Overflow calculating L1 memory size.\n");
392 		return -ENOMEM;
393 	}
394 
395 	/* Make sure enough space was supplied. */
396 	if (l1_mem_size < l1_gpt_mem_sz) {
397 		ERROR("[GPT] Inadequate memory for L1 GPTs. ");
398 		ERROR("      Expected 0x%lx bytes. Got 0x%lx bytes\n",
399 		      l1_gpt_mem_sz, l1_mem_size);
400 		return -ENOMEM;
401 	}
402 
403 	VERBOSE("[GPT] Requested 0x%lx bytes for L1 GPTs.\n", l1_gpt_mem_sz);
404 	return 0;
405 }
406 
407 /*
408  * This function initializes L0 block descriptors (regions that cannot be
409  * transitioned at the granule level) according to the provided PAS.
410  *
411  * Parameters
412  *   *pas		Pointer to the structure defining the PAS region to
413  *			initialize.
414  */
415 static void gpt_generate_l0_blk_desc(pas_region_t *pas)
416 {
417 	uint64_t gpt_desc;
418 	unsigned int end_idx;
419 	unsigned int idx;
420 	uint64_t *l0_gpt_arr;
421 
422 	assert(gpt_config.plat_gpt_l0_base != 0U);
423 	assert(pas != NULL);
424 
425 	/*
426 	 * Checking of PAS parameters has already been done in
427 	 * gpt_validate_pas_mappings so no need to check the same things again.
428 	 */
429 
430 	l0_gpt_arr = (uint64_t *)gpt_config.plat_gpt_l0_base;
431 
432 	/* Create the GPT Block descriptor for this PAS region */
433 	gpt_desc = GPT_L0_BLK_DESC(GPT_PAS_ATTR_GPI(pas->attrs));
434 
435 	/* Start index of this region in L0 GPTs */
436 	idx = pas->base_pa >> GPT_L0_IDX_SHIFT;
437 
438 	/*
439 	 * Determine number of L0 GPT descriptors covered by
440 	 * this PAS region and use the count to populate these
441 	 * descriptors.
442 	 */
443 	end_idx = (pas->base_pa + pas->size) >> GPT_L0_IDX_SHIFT;
444 
445 	/* Generate the needed block descriptors. */
446 	for (; idx < end_idx; idx++) {
447 		l0_gpt_arr[idx] = gpt_desc;
448 		VERBOSE("[GPT] L0 entry (BLOCK) index %u [%p]: GPI = 0x%llx (0x%llx)\n",
449 			idx, &l0_gpt_arr[idx],
450 			(gpt_desc >> GPT_L0_BLK_DESC_GPI_SHIFT) &
451 			GPT_L0_BLK_DESC_GPI_MASK, l0_gpt_arr[idx]);
452 	}
453 }
454 
455 /*
456  * Helper function to determine if the end physical address lies in the same L0
457  * region as the current physical address. If true, the end physical address is
458  * returned else, the start address of the next region is returned.
459  *
460  * Parameters
461  *   cur_pa		Physical address of the current PA in the loop through
462  *			the range.
463  *   end_pa		Physical address of the end PA in a PAS range.
464  *
465  * Return
466  *   The PA of the end of the current range.
467  */
468 static uintptr_t gpt_get_l1_end_pa(uintptr_t cur_pa, uintptr_t end_pa)
469 {
470 	uintptr_t cur_idx;
471 	uintptr_t end_idx;
472 
473 	cur_idx = cur_pa >> GPT_L0_IDX_SHIFT;
474 	end_idx = end_pa >> GPT_L0_IDX_SHIFT;
475 
476 	assert(cur_idx <= end_idx);
477 
478 	if (cur_idx == end_idx) {
479 		return end_pa;
480 	}
481 
482 	return (cur_idx + 1U) << GPT_L0_IDX_SHIFT;
483 }
484 
485 /*
486  * Helper function to fill out GPI entries in a single L1 table. This function
487  * fills out entire L1 descriptors at a time to save memory writes.
488  *
489  * Parameters
490  *   gpi		GPI to set this range to
491  *   l1			Pointer to L1 table to fill out
492  *   first		Address of first granule in range.
493  *   last		Address of last granule in range (inclusive).
494  */
495 static void gpt_fill_l1_tbl(uint64_t gpi, uint64_t *l1, uintptr_t first,
496 			    uintptr_t last)
497 {
498 	uint64_t gpi_field = GPT_BUILD_L1_DESC(gpi);
499 	uint64_t gpi_mask = 0xFFFFFFFFFFFFFFFF;
500 
501 	assert(first <= last);
502 	assert((first & (GPT_PGS_ACTUAL_SIZE(gpt_config.p) - 1)) == 0U);
503 	assert((last & (GPT_PGS_ACTUAL_SIZE(gpt_config.p) - 1)) == 0U);
504 	assert(GPT_L0_IDX(first) == GPT_L0_IDX(last));
505 	assert(l1 != NULL);
506 
507 	/* Shift the mask if we're starting in the middle of an L1 entry. */
508 	gpi_mask = gpi_mask << (GPT_L1_GPI_IDX(gpt_config.p, first) << 2);
509 
510 	/* Fill out each L1 entry for this region. */
511 	for (unsigned int i = GPT_L1_IDX(gpt_config.p, first);
512 	     i <= GPT_L1_IDX(gpt_config.p, last); i++) {
513 		/* Account for stopping in the middle of an L1 entry. */
514 		if (i == GPT_L1_IDX(gpt_config.p, last)) {
515 			gpi_mask &= (gpi_mask >> ((15 -
516 				    GPT_L1_GPI_IDX(gpt_config.p, last)) << 2));
517 		}
518 
519 		/* Write GPI values. */
520 		assert((l1[i] & gpi_mask) ==
521 		       (GPT_BUILD_L1_DESC(GPT_GPI_ANY) & gpi_mask));
522 		l1[i] = (l1[i] & ~gpi_mask) | (gpi_mask & gpi_field);
523 
524 		/* Reset mask. */
525 		gpi_mask = 0xFFFFFFFFFFFFFFFF;
526 	}
527 }
528 
529 /*
530  * This function finds the next available unused L1 table and initializes all
531  * granules descriptor entries to GPI_ANY. This ensures that there are no chunks
532  * of GPI_NO_ACCESS (0b0000) memory floating around in the system in the
533  * event that a PAS region stops midway through an L1 table, thus guaranteeing
534  * that all memory not explicitly assigned is GPI_ANY. This function does not
535  * check for overflow conditions, that should be done by the caller.
536  *
537  * Return
538  *   Pointer to the next available L1 table.
539  */
540 static uint64_t *gpt_get_new_l1_tbl(void)
541 {
542 	/* Retrieve the next L1 table. */
543 	uint64_t *l1 = (uint64_t *)((uint64_t)(gpt_l1_tbl) +
544 		       (GPT_L1_TABLE_SIZE(gpt_config.p) *
545 		       gpt_next_l1_tbl_idx));
546 
547 	/* Increment L1 counter. */
548 	gpt_next_l1_tbl_idx++;
549 
550 	/* Initialize all GPIs to GPT_GPI_ANY */
551 	for (unsigned int i = 0U; i < GPT_L1_ENTRY_COUNT(gpt_config.p); i++) {
552 		l1[i] = GPT_BUILD_L1_DESC(GPT_GPI_ANY);
553 	}
554 
555 	return l1;
556 }
557 
558 /*
559  * When L1 tables are needed, this function creates the necessary L0 table
560  * descriptors and fills out the L1 table entries according to the supplied
561  * PAS range.
562  *
563  * Parameters
564  *   *pas		Pointer to the structure defining the PAS region.
565  */
566 static void gpt_generate_l0_tbl_desc(pas_region_t *pas)
567 {
568 	uintptr_t end_pa;
569 	uintptr_t cur_pa;
570 	uintptr_t last_gran_pa;
571 	uint64_t *l0_gpt_base;
572 	uint64_t *l1_gpt_arr;
573 	unsigned int l0_idx;
574 
575 	assert(gpt_config.plat_gpt_l0_base != 0U);
576 	assert(pas != NULL);
577 
578 	/*
579 	 * Checking of PAS parameters has already been done in
580 	 * gpt_validate_pas_mappings so no need to check the same things again.
581 	 */
582 
583 	end_pa = pas->base_pa + pas->size;
584 	l0_gpt_base = (uint64_t *)gpt_config.plat_gpt_l0_base;
585 
586 	/* We start working from the granule at base PA */
587 	cur_pa = pas->base_pa;
588 
589 	/* Iterate over each L0 region in this memory range. */
590 	for (l0_idx = GPT_L0_IDX(pas->base_pa);
591 	     l0_idx <= GPT_L0_IDX(end_pa - 1U);
592 	     l0_idx++) {
593 
594 		/*
595 		 * See if the L0 entry is already a table descriptor or if we
596 		 * need to create one.
597 		 */
598 		if (GPT_L0_TYPE(l0_gpt_base[l0_idx]) == GPT_L0_TYPE_TBL_DESC) {
599 			/* Get the L1 array from the L0 entry. */
600 			l1_gpt_arr = GPT_L0_TBLD_ADDR(l0_gpt_base[l0_idx]);
601 		} else {
602 			/* Get a new L1 table from the L1 memory space. */
603 			l1_gpt_arr = gpt_get_new_l1_tbl();
604 
605 			/* Fill out the L0 descriptor and flush it. */
606 			l0_gpt_base[l0_idx] = GPT_L0_TBL_DESC(l1_gpt_arr);
607 		}
608 
609 		VERBOSE("[GPT] L0 entry (TABLE) index %u [%p] ==> L1 Addr 0x%llx (0x%llx)\n",
610 			l0_idx, &l0_gpt_base[l0_idx],
611 			(unsigned long long)(l1_gpt_arr),
612 			l0_gpt_base[l0_idx]);
613 
614 		/*
615 		 * Determine the PA of the last granule in this L0 descriptor.
616 		 */
617 		last_gran_pa = gpt_get_l1_end_pa(cur_pa, end_pa) -
618 			       GPT_PGS_ACTUAL_SIZE(gpt_config.p);
619 
620 		/*
621 		 * Fill up L1 GPT entries between these two addresses. This
622 		 * function needs the addresses of the first granule and last
623 		 * granule in the range.
624 		 */
625 		gpt_fill_l1_tbl(GPT_PAS_ATTR_GPI(pas->attrs), l1_gpt_arr,
626 				cur_pa, last_gran_pa);
627 
628 		/* Advance cur_pa to first granule in next L0 region. */
629 		cur_pa = gpt_get_l1_end_pa(cur_pa, end_pa);
630 	}
631 }
632 
633 /*
634  * This function flushes a range of L0 descriptors used by a given PAS region
635  * array. There is a chance that some unmodified L0 descriptors would be flushed
636  * in the case that there are "holes" in an array of PAS regions but overall
637  * this should be faster than individually flushing each modified L0 descriptor
638  * as they are created.
639  *
640  * Parameters
641  *   *pas		Pointer to an array of PAS regions.
642  *   pas_count		Number of entries in the PAS array.
643  */
644 static void flush_l0_for_pas_array(pas_region_t *pas, unsigned int pas_count)
645 {
646 	unsigned int idx;
647 	unsigned int start_idx;
648 	unsigned int end_idx;
649 	uint64_t *l0 = (uint64_t *)gpt_config.plat_gpt_l0_base;
650 
651 	assert(pas != NULL);
652 	assert(pas_count > 0);
653 
654 	/* Initial start and end values. */
655 	start_idx = GPT_L0_IDX(pas[0].base_pa);
656 	end_idx = GPT_L0_IDX(pas[0].base_pa + pas[0].size - 1);
657 
658 	/* Find lowest and highest L0 indices used in this PAS array. */
659 	for (idx = 1; idx < pas_count; idx++) {
660 		if (GPT_L0_IDX(pas[idx].base_pa) < start_idx) {
661 			start_idx = GPT_L0_IDX(pas[idx].base_pa);
662 		}
663 		if (GPT_L0_IDX(pas[idx].base_pa + pas[idx].size - 1) > end_idx) {
664 			end_idx = GPT_L0_IDX(pas[idx].base_pa + pas[idx].size - 1);
665 		}
666 	}
667 
668 	/*
669 	 * Flush all covered L0 descriptors, add 1 because we need to include
670 	 * the end index value.
671 	 */
672 	flush_dcache_range((uintptr_t)&l0[start_idx],
673 			   ((end_idx + 1) - start_idx) * sizeof(uint64_t));
674 }
675 
676 /*
677  * Public API to enable granule protection checks once the tables have all been
678  * initialized. This function is called at first initialization and then again
679  * later during warm boots of CPU cores.
680  *
681  * Return
682  *   Negative Linux error code in the event of a failure, 0 for success.
683  */
684 int gpt_enable(void)
685 {
686 	u_register_t gpccr_el3;
687 
688 	/*
689 	 * Granule tables must be initialised before enabling
690 	 * granule protection.
691 	 */
692 	if (gpt_config.plat_gpt_l0_base == 0U) {
693 		ERROR("[GPT] Tables have not been initialized!\n");
694 		return -EPERM;
695 	}
696 
697 	/* Invalidate any stale TLB entries */
698 	tlbipaallos();
699 	dsb();
700 
701 	/* Write the base address of the L0 tables into GPTBR */
702 	write_gptbr_el3(((gpt_config.plat_gpt_l0_base >> GPTBR_BADDR_VAL_SHIFT)
703 			>> GPTBR_BADDR_SHIFT) & GPTBR_BADDR_MASK);
704 
705 	/* GPCCR_EL3.PPS */
706 	gpccr_el3 = SET_GPCCR_PPS(gpt_config.pps);
707 
708 	/* GPCCR_EL3.PGS */
709 	gpccr_el3 |= SET_GPCCR_PGS(gpt_config.pgs);
710 
711 	/* Set shareability attribute to Outher Shareable */
712 	gpccr_el3 |= SET_GPCCR_SH(GPCCR_SH_OS);
713 
714 	/* Outer and Inner cacheability set to Normal memory, WB, RA, WA. */
715 	gpccr_el3 |= SET_GPCCR_ORGN(GPCCR_ORGN_WB_RA_WA);
716 	gpccr_el3 |= SET_GPCCR_IRGN(GPCCR_IRGN_WB_RA_WA);
717 
718 	/* Enable GPT */
719 	gpccr_el3 |= GPCCR_GPC_BIT;
720 
721 	/* TODO: Configure GPCCR_EL3_GPCP for Fault control. */
722 	write_gpccr_el3(gpccr_el3);
723 	tlbipaallos();
724 	dsb();
725 	isb();
726 
727 	return 0;
728 }
729 
730 /*
731  * Public API to disable granule protection checks.
732  */
733 void gpt_disable(void)
734 {
735 	u_register_t gpccr_el3 = read_gpccr_el3();
736 
737 	write_gpccr_el3(gpccr_el3 & ~GPCCR_GPC_BIT);
738 	dsbsy();
739 	isb();
740 }
741 
742 /*
743  * Public API that initializes the entire protected space to GPT_GPI_ANY using
744  * the L0 tables (block descriptors). Ideally, this function is invoked prior
745  * to DDR discovery and initialization. The MMU must be initialized before
746  * calling this function.
747  *
748  * Parameters
749  *   pps		PPS value to use for table generation
750  *   l0_mem_base	Base address of L0 tables in memory.
751  *   l0_mem_size	Total size of memory available for L0 tables.
752  *
753  * Return
754  *   Negative Linux error code in the event of a failure, 0 for success.
755  */
756 int gpt_init_l0_tables(unsigned int pps, uintptr_t l0_mem_base,
757 		       size_t l0_mem_size)
758 {
759 	int ret;
760 	uint64_t gpt_desc;
761 
762 	/* Ensure that MMU and caches are enabled. */
763 	assert((read_sctlr_el3() & SCTLR_C_BIT) != 0U);
764 
765 	/* Validate other parameters. */
766 	ret = gpt_validate_l0_params(pps, l0_mem_base, l0_mem_size);
767 	if (ret < 0) {
768 		return ret;
769 	}
770 
771 	/* Create the descriptor to initialize L0 entries with. */
772 	gpt_desc = GPT_L0_BLK_DESC(GPT_GPI_ANY);
773 
774 	/* Iterate through all L0 entries */
775 	for (unsigned int i = 0U; i < GPT_L0_REGION_COUNT(gpt_config.t); i++) {
776 		((uint64_t *)l0_mem_base)[i] = gpt_desc;
777 	}
778 
779 	/* Flush updated L0 tables to memory. */
780 	flush_dcache_range((uintptr_t)l0_mem_base,
781 			   (size_t)GPT_L0_TABLE_SIZE(gpt_config.t));
782 
783 	/* Stash the L0 base address once initial setup is complete. */
784 	gpt_config.plat_gpt_l0_base = l0_mem_base;
785 
786 	return 0;
787 }
788 
789 /*
790  * Public API that carves out PAS regions from the L0 tables and builds any L1
791  * tables that are needed. This function ideally is run after DDR discovery and
792  * initialization. The L0 tables must have already been initialized to GPI_ANY
793  * when this function is called.
794  *
795  * This function can be called multiple times with different L1 memory ranges
796  * and PAS regions if it is desirable to place L1 tables in different locations
797  * in memory. (ex: you have multiple DDR banks and want to place the L1 tables
798  * in the DDR bank that they control)
799  *
800  * Parameters
801  *   pgs		PGS value to use for table generation.
802  *   l1_mem_base	Base address of memory used for L1 tables.
803  *   l1_mem_size	Total size of memory available for L1 tables.
804  *   *pas_regions	Pointer to PAS regions structure array.
805  *   pas_count		Total number of PAS regions.
806  *
807  * Return
808  *   Negative Linux error code in the event of a failure, 0 for success.
809  */
810 int gpt_init_pas_l1_tables(gpccr_pgs_e pgs, uintptr_t l1_mem_base,
811 			   size_t l1_mem_size, pas_region_t *pas_regions,
812 			   unsigned int pas_count)
813 {
814 	int ret;
815 	int l1_gpt_cnt;
816 
817 	/* Ensure that MMU and caches are enabled. */
818 	assert((read_sctlr_el3() & SCTLR_C_BIT) != 0U);
819 
820 	/* PGS is needed for gpt_validate_pas_mappings so check it now. */
821 	if (pgs > GPT_PGS_MAX) {
822 		ERROR("[GPT] Invalid PGS: 0x%x\n", pgs);
823 		return -EINVAL;
824 	}
825 	gpt_config.pgs = pgs;
826 	gpt_config.p = gpt_p_lookup[pgs];
827 
828 	/* Make sure L0 tables have been initialized. */
829 	if (gpt_config.plat_gpt_l0_base == 0U) {
830 		ERROR("[GPT] L0 tables must be initialized first!\n");
831 		return -EPERM;
832 	}
833 
834 	/* Check if L1 GPTs are required and how many. */
835 	l1_gpt_cnt = gpt_validate_pas_mappings(pas_regions, pas_count);
836 	if (l1_gpt_cnt < 0) {
837 		return l1_gpt_cnt;
838 	}
839 
840 	VERBOSE("[GPT] %u L1 GPTs requested.\n", l1_gpt_cnt);
841 
842 	/* If L1 tables are needed then validate the L1 parameters. */
843 	if (l1_gpt_cnt > 0) {
844 		ret = gpt_validate_l1_params(l1_mem_base, l1_mem_size,
845 		      l1_gpt_cnt);
846 		if (ret < 0) {
847 			return ret;
848 		}
849 
850 		/* Set up parameters for L1 table generation. */
851 		gpt_l1_tbl = l1_mem_base;
852 		gpt_next_l1_tbl_idx = 0U;
853 	}
854 
855 	INFO("[GPT] Boot Configuration\n");
856 	INFO("  PPS/T:     0x%x/%u\n", gpt_config.pps, gpt_config.t);
857 	INFO("  PGS/P:     0x%x/%u\n", gpt_config.pgs, gpt_config.p);
858 	INFO("  L0GPTSZ/S: 0x%x/%u\n", GPT_L0GPTSZ, GPT_S_VAL);
859 	INFO("  PAS count: 0x%x\n", pas_count);
860 	INFO("  L0 base:   0x%lx\n", gpt_config.plat_gpt_l0_base);
861 
862 	/* Generate the tables in memory. */
863 	for (unsigned int idx = 0U; idx < pas_count; idx++) {
864 		INFO("[GPT] PAS[%u]: base 0x%lx, size 0x%lx, GPI 0x%x, type 0x%x\n",
865 		     idx, pas_regions[idx].base_pa, pas_regions[idx].size,
866 		     GPT_PAS_ATTR_GPI(pas_regions[idx].attrs),
867 		     GPT_PAS_ATTR_MAP_TYPE(pas_regions[idx].attrs));
868 
869 		/* Check if a block or table descriptor is required */
870 		if (GPT_PAS_ATTR_MAP_TYPE(pas_regions[idx].attrs) ==
871 		    GPT_PAS_ATTR_MAP_TYPE_BLOCK) {
872 			gpt_generate_l0_blk_desc(&pas_regions[idx]);
873 
874 		} else {
875 			gpt_generate_l0_tbl_desc(&pas_regions[idx]);
876 		}
877 	}
878 
879 	/* Flush modified L0 tables. */
880 	flush_l0_for_pas_array(pas_regions, pas_count);
881 
882 	/* Flush L1 tables if needed. */
883 	if (l1_gpt_cnt > 0) {
884 		flush_dcache_range(l1_mem_base,
885 				   GPT_L1_TABLE_SIZE(gpt_config.p) *
886 				   l1_gpt_cnt);
887 	}
888 
889 	/* Make sure that all the entries are written to the memory. */
890 	dsbishst();
891 
892 	return 0;
893 }
894 
895 /*
896  * Public API to initialize the runtime gpt_config structure based on the values
897  * present in the GPTBR_EL3 and GPCCR_EL3 registers. GPT initialization
898  * typically happens in a bootloader stage prior to setting up the EL3 runtime
899  * environment for the granule transition service so this function detects the
900  * initialization from a previous stage. Granule protection checks must be
901  * enabled already or this function will return an error.
902  *
903  * Return
904  *   Negative Linux error code in the event of a failure, 0 for success.
905  */
906 int gpt_runtime_init(void)
907 {
908 	u_register_t reg;
909 
910 	/* Ensure that MMU and caches are enabled. */
911 	assert((read_sctlr_el3() & SCTLR_C_BIT) != 0U);
912 
913 	/* Ensure GPC are already enabled. */
914 	if ((read_gpccr_el3() & GPCCR_GPC_BIT) == 0U) {
915 		ERROR("[GPT] Granule protection checks are not enabled!\n");
916 		return -EPERM;
917 	}
918 
919 	/*
920 	 * Read the L0 table address from GPTBR, we don't need the L1 base
921 	 * address since those are included in the L0 tables as needed.
922 	 */
923 	reg = read_gptbr_el3();
924 	gpt_config.plat_gpt_l0_base = ((reg >> GPTBR_BADDR_SHIFT) &
925 				      GPTBR_BADDR_MASK) <<
926 				      GPTBR_BADDR_VAL_SHIFT;
927 
928 	/* Read GPCCR to get PGS and PPS values. */
929 	reg = read_gpccr_el3();
930 	gpt_config.pps = (reg >> GPCCR_PPS_SHIFT) & GPCCR_PPS_MASK;
931 	gpt_config.t = gpt_t_lookup[gpt_config.pps];
932 	gpt_config.pgs = (reg >> GPCCR_PGS_SHIFT) & GPCCR_PGS_MASK;
933 	gpt_config.p = gpt_p_lookup[gpt_config.pgs];
934 
935 	VERBOSE("[GPT] Runtime Configuration\n");
936 	VERBOSE("  PPS/T:     0x%x/%u\n", gpt_config.pps, gpt_config.t);
937 	VERBOSE("  PGS/P:     0x%x/%u\n", gpt_config.pgs, gpt_config.p);
938 	VERBOSE("  L0GPTSZ/S: 0x%x/%u\n", GPT_L0GPTSZ, GPT_S_VAL);
939 	VERBOSE("  L0 base:   0x%lx\n", gpt_config.plat_gpt_l0_base);
940 
941 	return 0;
942 }
943 
944 /*
945  * The L1 descriptors are protected by a spinlock to ensure that multiple
946  * CPUs do not attempt to change the descriptors at once. In the future it
947  * would be better to have separate spinlocks for each L1 descriptor.
948  */
949 static spinlock_t gpt_lock;
950 
951 /*
952  * Check if caller is allowed to transition a PAS.
953  *
954  * - Secure world caller can only request S <-> NS transitions on a
955  *   granule that is already in either S or NS PAS.
956  *
957  * - Realm world caller can only request R <-> NS transitions on a
958  *   granule that is already in either R or NS PAS.
959  *
960  * Parameters
961  *   src_sec_state	Security state of the caller.
962  *   current_gpi	Current GPI of the granule.
963  *   target_gpi		Requested new GPI for the granule.
964  *
965  * Return
966  *   Negative Linux error code in the event of a failure, 0 for success.
967  */
968 static int gpt_check_transition_gpi(unsigned int src_sec_state,
969 				    unsigned int current_gpi,
970 				    unsigned int target_gpi)
971 {
972 	unsigned int check_gpi;
973 
974 	/* Cannot transition a granule to the state it is already in. */
975 	if (current_gpi == target_gpi) {
976 		return -EINVAL;
977 	}
978 
979 	/* Check security state, only secure and realm can transition. */
980 	if (src_sec_state == SMC_FROM_REALM) {
981 		check_gpi = GPT_GPI_REALM;
982 	} else if (src_sec_state == SMC_FROM_SECURE) {
983 		check_gpi = GPT_GPI_SECURE;
984 	} else {
985 		return -EINVAL;
986 	}
987 
988 	/* Make sure security state is allowed to make the transition. */
989 	if ((target_gpi != check_gpi) && (target_gpi != GPT_GPI_NS)) {
990 		return -EINVAL;
991 	}
992 	if ((current_gpi != check_gpi) && (current_gpi != GPT_GPI_NS)) {
993 		return -EINVAL;
994 	}
995 
996 	return 0;
997 }
998 
999 /*
1000  * This function is the core of the granule transition service. When a granule
1001  * transition request occurs it is routed to this function where the request is
1002  * validated then fulfilled if possible.
1003  *
1004  * TODO: implement support for transitioning multiple granules at once.
1005  *
1006  * Parameters
1007  *   base		Base address of the region to transition, must be
1008  *			aligned to granule size.
1009  *   size		Size of region to transition, must be aligned to granule
1010  *			size.
1011  *   src_sec_state	Security state of the caller.
1012  *   target_pas		Target PAS of the specified memory region.
1013  *
1014  * Return
1015  *    Negative Linux error code in the event of a failure, 0 for success.
1016  */
1017 int gpt_transition_pas(uint64_t base, size_t size, unsigned int src_sec_state,
1018 	unsigned int target_pas)
1019 {
1020 	int idx;
1021 	unsigned int gpi_shift;
1022 	unsigned int gpi;
1023 	uint64_t gpt_l0_desc;
1024 	uint64_t gpt_l1_desc;
1025 	uint64_t *gpt_l1_addr;
1026 	uint64_t *gpt_l0_base;
1027 
1028 	/* Ensure that the tables have been set up before taking requests. */
1029 	assert(gpt_config.plat_gpt_l0_base != 0U);
1030 
1031 	/* Check for address range overflow. */
1032 	if ((ULONG_MAX - base) < size) {
1033 		VERBOSE("[GPT] Transition request address overflow!\n");
1034 		VERBOSE("      Base=0x%llx\n", base);
1035 		VERBOSE("      Size=0x%lx\n", size);
1036 		return -EINVAL;
1037 	}
1038 
1039 	/* Make sure base and size are valid. */
1040 	if (((base & (GPT_PGS_ACTUAL_SIZE(gpt_config.p) - 1)) != 0U) ||
1041 	    ((size & (GPT_PGS_ACTUAL_SIZE(gpt_config.p) - 1)) != 0U) ||
1042 	    (size == 0U) ||
1043 	    ((base + size) >= GPT_PPS_ACTUAL_SIZE(gpt_config.t))) {
1044 		VERBOSE("[GPT] Invalid granule transition address range!\n");
1045 		VERBOSE("      Base=0x%llx\n", base);
1046 		VERBOSE("      Size=0x%lx\n", size);
1047 		return -EINVAL;
1048 	}
1049 
1050 	/* See if this is a single granule transition or a range of granules. */
1051 	if (size != GPT_PGS_ACTUAL_SIZE(gpt_config.p)) {
1052 		/*
1053 		 * TODO: Add support for transitioning multiple granules with a
1054 		 * single call to this function.
1055 		 */
1056 		panic();
1057 	}
1058 
1059 	/* Get the L0 descriptor and make sure it is for a table. */
1060 	gpt_l0_base = (uint64_t *)gpt_config.plat_gpt_l0_base;
1061 	gpt_l0_desc = gpt_l0_base[GPT_L0_IDX(base)];
1062 	if (GPT_L0_TYPE(gpt_l0_desc) != GPT_L0_TYPE_TBL_DESC) {
1063 		VERBOSE("[GPT] Granule is not covered by a table descriptor!\n");
1064 		VERBOSE("      Base=0x%llx\n", base);
1065 		return -EINVAL;
1066 	}
1067 
1068 	/* Get the table index and GPI shift from PA. */
1069 	gpt_l1_addr = GPT_L0_TBLD_ADDR(gpt_l0_desc);
1070 	idx = GPT_L1_IDX(gpt_config.p, base);
1071 	gpi_shift = GPT_L1_GPI_IDX(gpt_config.p, base) << 2;
1072 
1073 	/*
1074 	 * Access to L1 tables is controlled by a global lock to ensure
1075 	 * that no more than one CPU is allowed to make changes at any
1076 	 * given time.
1077 	 */
1078 	spin_lock(&gpt_lock);
1079 	gpt_l1_desc = gpt_l1_addr[idx];
1080 	gpi = (gpt_l1_desc >> gpi_shift) & GPT_L1_GRAN_DESC_GPI_MASK;
1081 
1082 	/* Make sure caller state and source/target PAS are allowed. */
1083 	if (gpt_check_transition_gpi(src_sec_state, gpi, target_pas) < 0) {
1084 		spin_unlock(&gpt_lock);
1085 			VERBOSE("[GPT] Invalid caller state and PAS combo!\n");
1086 		VERBOSE("      Caller: %u, Current GPI: %u, Target GPI: %u\n",
1087 			src_sec_state, gpi, target_pas);
1088 		return -EPERM;
1089 	}
1090 
1091 	/* Clear existing GPI encoding and transition granule. */
1092 	gpt_l1_desc &= ~(GPT_L1_GRAN_DESC_GPI_MASK << gpi_shift);
1093 	gpt_l1_desc |= ((uint64_t)target_pas << gpi_shift);
1094 	gpt_l1_addr[idx] = gpt_l1_desc;
1095 
1096 	/* Ensure that the write operation happens before the unlock. */
1097 	dmbishst();
1098 
1099 	/* Unlock access to the L1 tables. */
1100 	spin_unlock(&gpt_lock);
1101 
1102 	/* Cache maintenance. */
1103 	clean_dcache_range((uintptr_t)&gpt_l1_addr[idx],
1104 			   sizeof(uint64_t));
1105 	gpt_tlbi_by_pa(base, GPT_PGS_ACTUAL_SIZE(gpt_config.p));
1106 	dsbishst();
1107 
1108 	VERBOSE("[GPT] Granule 0x%llx, GPI 0x%x->0x%x\n", base, gpi,
1109 		target_pas);
1110 
1111 	return 0;
1112 }
1113