1 /*
2 * CPU-agnostic ARM page table allocator.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
15 *
16 * Copyright (C) 2014 ARM Limited
17 *
18 * Author: Will Deacon <will.deacon@arm.com>
19 */
20
21 #define pr_fmt(fmt) "arm-lpae io-pgtable: " fmt
22
23 #include <linux/iommu.h>
24 #include <linux/kernel.h>
25 #include <linux/sizes.h>
26 #include <linux/slab.h>
27 #include <linux/types.h>
28
29 #include <asm/barrier.h>
30
31 #include "io-pgtable.h"
32
33 #define ARM_LPAE_MAX_ADDR_BITS 48
34 #define ARM_LPAE_S2_MAX_CONCAT_PAGES 16
35 #define ARM_LPAE_MAX_LEVELS 4
36
37 /* Struct accessors */
38 #define io_pgtable_to_data(x) \
39 container_of((x), struct arm_lpae_io_pgtable, iop)
40
41 #define io_pgtable_ops_to_pgtable(x) \
42 container_of((x), struct io_pgtable, ops)
43
44 #define io_pgtable_ops_to_data(x) \
45 io_pgtable_to_data(io_pgtable_ops_to_pgtable(x))
46
47 /*
48 * For consistency with the architecture, we always consider
49 * ARM_LPAE_MAX_LEVELS levels, with the walk starting at level n >=0
50 */
51 #define ARM_LPAE_START_LVL(d) (ARM_LPAE_MAX_LEVELS - (d)->levels)
52
53 /*
54 * Calculate the right shift amount to get to the portion describing level l
55 * in a virtual address mapped by the pagetable in d.
56 */
57 #define ARM_LPAE_LVL_SHIFT(l,d) \
58 ((((d)->levels - ((l) - ARM_LPAE_START_LVL(d) + 1)) \
59 * (d)->bits_per_level) + (d)->pg_shift)
60
61 #define ARM_LPAE_PAGES_PER_PGD(d) \
62 DIV_ROUND_UP((d)->pgd_size, 1UL << (d)->pg_shift)
63
64 /*
65 * Calculate the index at level l used to map virtual address a using the
66 * pagetable in d.
67 */
68 #define ARM_LPAE_PGD_IDX(l,d) \
69 ((l) == ARM_LPAE_START_LVL(d) ? ilog2(ARM_LPAE_PAGES_PER_PGD(d)) : 0)
70
71 #define ARM_LPAE_LVL_IDX(a,l,d) \
72 (((u64)(a) >> ARM_LPAE_LVL_SHIFT(l,d)) & \
73 ((1 << ((d)->bits_per_level + ARM_LPAE_PGD_IDX(l,d))) - 1))
74
75 /* Calculate the block/page mapping size at level l for pagetable in d. */
76 #define ARM_LPAE_BLOCK_SIZE(l,d) \
77 (1 << (ilog2(sizeof(arm_lpae_iopte)) + \
78 ((ARM_LPAE_MAX_LEVELS - (l)) * (d)->bits_per_level)))
79
80 /* Page table bits */
81 #define ARM_LPAE_PTE_TYPE_SHIFT 0
82 #define ARM_LPAE_PTE_TYPE_MASK 0x3
83
84 #define ARM_LPAE_PTE_TYPE_BLOCK 1
85 #define ARM_LPAE_PTE_TYPE_TABLE 3
86 #define ARM_LPAE_PTE_TYPE_PAGE 3
87
88 #define ARM_LPAE_PTE_NSTABLE (((arm_lpae_iopte)1) << 63)
89 #define ARM_LPAE_PTE_XN (((arm_lpae_iopte)3) << 53)
90 #define ARM_LPAE_PTE_AF (((arm_lpae_iopte)1) << 10)
91 #define ARM_LPAE_PTE_SH_NS (((arm_lpae_iopte)0) << 8)
92 #define ARM_LPAE_PTE_SH_OS (((arm_lpae_iopte)2) << 8)
93 #define ARM_LPAE_PTE_SH_IS (((arm_lpae_iopte)3) << 8)
94 #define ARM_LPAE_PTE_NS (((arm_lpae_iopte)1) << 5)
95 #define ARM_LPAE_PTE_VALID (((arm_lpae_iopte)1) << 0)
96
97 #define ARM_LPAE_PTE_ATTR_LO_MASK (((arm_lpae_iopte)0x3ff) << 2)
98 /* Ignore the contiguous bit for block splitting */
99 #define ARM_LPAE_PTE_ATTR_HI_MASK (((arm_lpae_iopte)6) << 52)
100 #define ARM_LPAE_PTE_ATTR_MASK (ARM_LPAE_PTE_ATTR_LO_MASK | \
101 ARM_LPAE_PTE_ATTR_HI_MASK)
102
103 /* Stage-1 PTE */
104 #define ARM_LPAE_PTE_AP_UNPRIV (((arm_lpae_iopte)1) << 6)
105 #define ARM_LPAE_PTE_AP_RDONLY (((arm_lpae_iopte)2) << 6)
106 #define ARM_LPAE_PTE_ATTRINDX_SHIFT 2
107 #define ARM_LPAE_PTE_nG (((arm_lpae_iopte)1) << 11)
108
109 /* Stage-2 PTE */
110 #define ARM_LPAE_PTE_HAP_FAULT (((arm_lpae_iopte)0) << 6)
111 #define ARM_LPAE_PTE_HAP_READ (((arm_lpae_iopte)1) << 6)
112 #define ARM_LPAE_PTE_HAP_WRITE (((arm_lpae_iopte)2) << 6)
113 #define ARM_LPAE_PTE_MEMATTR_OIWB (((arm_lpae_iopte)0xf) << 2)
114 #define ARM_LPAE_PTE_MEMATTR_NC (((arm_lpae_iopte)0x5) << 2)
115 #define ARM_LPAE_PTE_MEMATTR_DEV (((arm_lpae_iopte)0x1) << 2)
116
117 /* Register bits */
118 #define ARM_32_LPAE_TCR_EAE (1 << 31)
119 #define ARM_64_LPAE_S2_TCR_RES1 (1 << 31)
120
121 #define ARM_LPAE_TCR_EPD1 (1 << 23)
122
123 #define ARM_LPAE_TCR_TG0_4K (0 << 14)
124 #define ARM_LPAE_TCR_TG0_64K (1 << 14)
125 #define ARM_LPAE_TCR_TG0_16K (2 << 14)
126
127 #define ARM_LPAE_TCR_SH0_SHIFT 12
128 #define ARM_LPAE_TCR_SH0_MASK 0x3
129 #define ARM_LPAE_TCR_SH_NS 0
130 #define ARM_LPAE_TCR_SH_OS 2
131 #define ARM_LPAE_TCR_SH_IS 3
132
133 #define ARM_LPAE_TCR_ORGN0_SHIFT 10
134 #define ARM_LPAE_TCR_IRGN0_SHIFT 8
135 #define ARM_LPAE_TCR_RGN_MASK 0x3
136 #define ARM_LPAE_TCR_RGN_NC 0
137 #define ARM_LPAE_TCR_RGN_WBWA 1
138 #define ARM_LPAE_TCR_RGN_WT 2
139 #define ARM_LPAE_TCR_RGN_WB 3
140
141 #define ARM_LPAE_TCR_SL0_SHIFT 6
142 #define ARM_LPAE_TCR_SL0_MASK 0x3
143
144 #define ARM_LPAE_TCR_T0SZ_SHIFT 0
145 #define ARM_LPAE_TCR_SZ_MASK 0xf
146
147 #define ARM_LPAE_TCR_PS_SHIFT 16
148 #define ARM_LPAE_TCR_PS_MASK 0x7
149
150 #define ARM_LPAE_TCR_IPS_SHIFT 32
151 #define ARM_LPAE_TCR_IPS_MASK 0x7
152
153 #define ARM_LPAE_TCR_PS_32_BIT 0x0ULL
154 #define ARM_LPAE_TCR_PS_36_BIT 0x1ULL
155 #define ARM_LPAE_TCR_PS_40_BIT 0x2ULL
156 #define ARM_LPAE_TCR_PS_42_BIT 0x3ULL
157 #define ARM_LPAE_TCR_PS_44_BIT 0x4ULL
158 #define ARM_LPAE_TCR_PS_48_BIT 0x5ULL
159
160 #define ARM_LPAE_MAIR_ATTR_SHIFT(n) ((n) << 3)
161 #define ARM_LPAE_MAIR_ATTR_MASK 0xff
162 #define ARM_LPAE_MAIR_ATTR_DEVICE 0x04
163 #define ARM_LPAE_MAIR_ATTR_NC 0x44
164 #define ARM_LPAE_MAIR_ATTR_WBRWA 0xff
165 #define ARM_LPAE_MAIR_ATTR_IDX_NC 0
166 #define ARM_LPAE_MAIR_ATTR_IDX_CACHE 1
167 #define ARM_LPAE_MAIR_ATTR_IDX_DEV 2
168
169 /* IOPTE accessors */
170 #define iopte_deref(pte,d) \
171 (__va((pte) & ((1ULL << ARM_LPAE_MAX_ADDR_BITS) - 1) \
172 & ~((1ULL << (d)->pg_shift) - 1)))
173
174 #define iopte_type(pte,l) \
175 (((pte) >> ARM_LPAE_PTE_TYPE_SHIFT) & ARM_LPAE_PTE_TYPE_MASK)
176
177 #define iopte_prot(pte) ((pte) & ARM_LPAE_PTE_ATTR_MASK)
178
179 #define iopte_leaf(pte,l) \
180 (l == (ARM_LPAE_MAX_LEVELS - 1) ? \
181 (iopte_type(pte,l) == ARM_LPAE_PTE_TYPE_PAGE) : \
182 (iopte_type(pte,l) == ARM_LPAE_PTE_TYPE_BLOCK))
183
184 #define iopte_to_pfn(pte,d) \
185 (((pte) & ((1ULL << ARM_LPAE_MAX_ADDR_BITS) - 1)) >> (d)->pg_shift)
186
187 #define pfn_to_iopte(pfn,d) \
188 (((pfn) << (d)->pg_shift) & ((1ULL << ARM_LPAE_MAX_ADDR_BITS) - 1))
189
190 struct arm_lpae_io_pgtable {
191 struct io_pgtable iop;
192
193 int levels;
194 size_t pgd_size;
195 unsigned long pg_shift;
196 unsigned long bits_per_level;
197
198 void *pgd;
199 };
200
201 typedef u64 arm_lpae_iopte;
202
203 static bool selftest_running = false;
204
__arm_lpae_dma_addr(void * pages)205 static dma_addr_t __arm_lpae_dma_addr(void *pages)
206 {
207 return (dma_addr_t)virt_to_phys(pages);
208 }
209
__arm_lpae_alloc_pages(size_t size,gfp_t gfp,struct io_pgtable_cfg * cfg)210 static void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp,
211 struct io_pgtable_cfg *cfg)
212 {
213 struct device *dev = cfg->iommu_dev;
214 dma_addr_t dma;
215 void *pages = alloc_pages_exact(size, gfp | __GFP_ZERO);
216
217 if (!pages)
218 return NULL;
219
220 if (!selftest_running) {
221 dma = dma_map_single(dev, pages, size, DMA_TO_DEVICE);
222 if (dma_mapping_error(dev, dma))
223 goto out_free;
224 /*
225 * We depend on the IOMMU being able to work with any physical
226 * address directly, so if the DMA layer suggests otherwise by
227 * translating or truncating them, that bodes very badly...
228 */
229 if (dma != virt_to_phys(pages))
230 goto out_unmap;
231 }
232
233 return pages;
234
235 out_unmap:
236 dev_err(dev, "Cannot accommodate DMA translation for IOMMU page tables\n");
237 dma_unmap_single(dev, dma, size, DMA_TO_DEVICE);
238 out_free:
239 free_pages_exact(pages, size);
240 return NULL;
241 }
242
__arm_lpae_free_pages(void * pages,size_t size,struct io_pgtable_cfg * cfg)243 static void __arm_lpae_free_pages(void *pages, size_t size,
244 struct io_pgtable_cfg *cfg)
245 {
246 if (!selftest_running)
247 dma_unmap_single(cfg->iommu_dev, __arm_lpae_dma_addr(pages),
248 size, DMA_TO_DEVICE);
249 free_pages_exact(pages, size);
250 }
251
__arm_lpae_set_pte(arm_lpae_iopte * ptep,arm_lpae_iopte pte,struct io_pgtable_cfg * cfg)252 static void __arm_lpae_set_pte(arm_lpae_iopte *ptep, arm_lpae_iopte pte,
253 struct io_pgtable_cfg *cfg)
254 {
255 *ptep = pte;
256
257 if (!selftest_running)
258 dma_sync_single_for_device(cfg->iommu_dev,
259 __arm_lpae_dma_addr(ptep),
260 sizeof(pte), DMA_TO_DEVICE);
261 }
262
263 static int __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
264 unsigned long iova, size_t size, int lvl,
265 arm_lpae_iopte *ptep);
266
arm_lpae_init_pte(struct arm_lpae_io_pgtable * data,unsigned long iova,phys_addr_t paddr,arm_lpae_iopte prot,int lvl,arm_lpae_iopte * ptep)267 static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
268 unsigned long iova, phys_addr_t paddr,
269 arm_lpae_iopte prot, int lvl,
270 arm_lpae_iopte *ptep)
271 {
272 arm_lpae_iopte pte = prot;
273 struct io_pgtable_cfg *cfg = &data->iop.cfg;
274
275 if (iopte_leaf(*ptep, lvl)) {
276 /* We require an unmap first */
277 WARN_ON(!selftest_running);
278 return -EEXIST;
279 } else if (iopte_type(*ptep, lvl) == ARM_LPAE_PTE_TYPE_TABLE) {
280 /*
281 * We need to unmap and free the old table before
282 * overwriting it with a block entry.
283 */
284 arm_lpae_iopte *tblp;
285 size_t sz = ARM_LPAE_BLOCK_SIZE(lvl, data);
286
287 tblp = ptep - ARM_LPAE_LVL_IDX(iova, lvl, data);
288 if (WARN_ON(__arm_lpae_unmap(data, iova, sz, lvl, tblp) != sz))
289 return -EINVAL;
290 }
291
292 if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS)
293 pte |= ARM_LPAE_PTE_NS;
294
295 if (lvl == ARM_LPAE_MAX_LEVELS - 1)
296 pte |= ARM_LPAE_PTE_TYPE_PAGE;
297 else
298 pte |= ARM_LPAE_PTE_TYPE_BLOCK;
299
300 pte |= ARM_LPAE_PTE_AF | ARM_LPAE_PTE_SH_IS;
301 pte |= pfn_to_iopte(paddr >> data->pg_shift, data);
302
303 __arm_lpae_set_pte(ptep, pte, cfg);
304 return 0;
305 }
306
__arm_lpae_map(struct arm_lpae_io_pgtable * data,unsigned long iova,phys_addr_t paddr,size_t size,arm_lpae_iopte prot,int lvl,arm_lpae_iopte * ptep)307 static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
308 phys_addr_t paddr, size_t size, arm_lpae_iopte prot,
309 int lvl, arm_lpae_iopte *ptep)
310 {
311 arm_lpae_iopte *cptep, pte;
312 size_t block_size = ARM_LPAE_BLOCK_SIZE(lvl, data);
313 struct io_pgtable_cfg *cfg = &data->iop.cfg;
314
315 /* Find our entry at the current level */
316 ptep += ARM_LPAE_LVL_IDX(iova, lvl, data);
317
318 /* If we can install a leaf entry at this level, then do so */
319 if (size == block_size && (size & cfg->pgsize_bitmap))
320 return arm_lpae_init_pte(data, iova, paddr, prot, lvl, ptep);
321
322 /* We can't allocate tables at the final level */
323 if (WARN_ON(lvl >= ARM_LPAE_MAX_LEVELS - 1))
324 return -EINVAL;
325
326 /* Grab a pointer to the next level */
327 pte = *ptep;
328 if (!pte) {
329 cptep = __arm_lpae_alloc_pages(1UL << data->pg_shift,
330 GFP_ATOMIC, cfg);
331 if (!cptep)
332 return -ENOMEM;
333
334 pte = __pa(cptep) | ARM_LPAE_PTE_TYPE_TABLE;
335 if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS)
336 pte |= ARM_LPAE_PTE_NSTABLE;
337 __arm_lpae_set_pte(ptep, pte, cfg);
338 } else {
339 cptep = iopte_deref(pte, data);
340 }
341
342 /* Rinse, repeat */
343 return __arm_lpae_map(data, iova, paddr, size, prot, lvl + 1, cptep);
344 }
345
arm_lpae_prot_to_pte(struct arm_lpae_io_pgtable * data,int prot)346 static arm_lpae_iopte arm_lpae_prot_to_pte(struct arm_lpae_io_pgtable *data,
347 int prot)
348 {
349 arm_lpae_iopte pte;
350
351 if (data->iop.fmt == ARM_64_LPAE_S1 ||
352 data->iop.fmt == ARM_32_LPAE_S1) {
353 pte = ARM_LPAE_PTE_AP_UNPRIV | ARM_LPAE_PTE_nG;
354
355 if (!(prot & IOMMU_WRITE) && (prot & IOMMU_READ))
356 pte |= ARM_LPAE_PTE_AP_RDONLY;
357
358 if (prot & IOMMU_CACHE)
359 pte |= (ARM_LPAE_MAIR_ATTR_IDX_CACHE
360 << ARM_LPAE_PTE_ATTRINDX_SHIFT);
361 } else {
362 pte = ARM_LPAE_PTE_HAP_FAULT;
363 if (prot & IOMMU_READ)
364 pte |= ARM_LPAE_PTE_HAP_READ;
365 if (prot & IOMMU_WRITE)
366 pte |= ARM_LPAE_PTE_HAP_WRITE;
367 if (prot & IOMMU_CACHE)
368 pte |= ARM_LPAE_PTE_MEMATTR_OIWB;
369 else
370 pte |= ARM_LPAE_PTE_MEMATTR_NC;
371 }
372
373 if (prot & IOMMU_NOEXEC)
374 pte |= ARM_LPAE_PTE_XN;
375
376 return pte;
377 }
378
arm_lpae_map(struct io_pgtable_ops * ops,unsigned long iova,phys_addr_t paddr,size_t size,int iommu_prot)379 static int arm_lpae_map(struct io_pgtable_ops *ops, unsigned long iova,
380 phys_addr_t paddr, size_t size, int iommu_prot)
381 {
382 struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
383 arm_lpae_iopte *ptep = data->pgd;
384 int ret, lvl = ARM_LPAE_START_LVL(data);
385 arm_lpae_iopte prot;
386
387 /* If no access, then nothing to do */
388 if (!(iommu_prot & (IOMMU_READ | IOMMU_WRITE)))
389 return 0;
390
391 prot = arm_lpae_prot_to_pte(data, iommu_prot);
392 ret = __arm_lpae_map(data, iova, paddr, size, prot, lvl, ptep);
393 /*
394 * Synchronise all PTE updates for the new mapping before there's
395 * a chance for anything to kick off a table walk for the new iova.
396 */
397 wmb();
398
399 return ret;
400 }
401
__arm_lpae_free_pgtable(struct arm_lpae_io_pgtable * data,int lvl,arm_lpae_iopte * ptep)402 static void __arm_lpae_free_pgtable(struct arm_lpae_io_pgtable *data, int lvl,
403 arm_lpae_iopte *ptep)
404 {
405 arm_lpae_iopte *start, *end;
406 unsigned long table_size;
407
408 if (lvl == ARM_LPAE_START_LVL(data))
409 table_size = data->pgd_size;
410 else
411 table_size = 1UL << data->pg_shift;
412
413 start = ptep;
414
415 /* Only leaf entries at the last level */
416 if (lvl == ARM_LPAE_MAX_LEVELS - 1)
417 end = ptep;
418 else
419 end = (void *)ptep + table_size;
420
421 while (ptep != end) {
422 arm_lpae_iopte pte = *ptep++;
423
424 if (!pte || iopte_leaf(pte, lvl))
425 continue;
426
427 __arm_lpae_free_pgtable(data, lvl + 1, iopte_deref(pte, data));
428 }
429
430 __arm_lpae_free_pages(start, table_size, &data->iop.cfg);
431 }
432
arm_lpae_free_pgtable(struct io_pgtable * iop)433 static void arm_lpae_free_pgtable(struct io_pgtable *iop)
434 {
435 struct arm_lpae_io_pgtable *data = io_pgtable_to_data(iop);
436
437 __arm_lpae_free_pgtable(data, ARM_LPAE_START_LVL(data), data->pgd);
438 kfree(data);
439 }
440
arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable * data,unsigned long iova,size_t size,arm_lpae_iopte prot,int lvl,arm_lpae_iopte * ptep,size_t blk_size)441 static int arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data,
442 unsigned long iova, size_t size,
443 arm_lpae_iopte prot, int lvl,
444 arm_lpae_iopte *ptep, size_t blk_size)
445 {
446 unsigned long blk_start, blk_end;
447 phys_addr_t blk_paddr;
448 arm_lpae_iopte table = 0;
449 struct io_pgtable_cfg *cfg = &data->iop.cfg;
450
451 blk_start = iova & ~(blk_size - 1);
452 blk_end = blk_start + blk_size;
453 blk_paddr = iopte_to_pfn(*ptep, data) << data->pg_shift;
454
455 for (; blk_start < blk_end; blk_start += size, blk_paddr += size) {
456 arm_lpae_iopte *tablep;
457
458 /* Unmap! */
459 if (blk_start == iova)
460 continue;
461
462 /* __arm_lpae_map expects a pointer to the start of the table */
463 tablep = &table - ARM_LPAE_LVL_IDX(blk_start, lvl, data);
464 if (__arm_lpae_map(data, blk_start, blk_paddr, size, prot, lvl,
465 tablep) < 0) {
466 if (table) {
467 /* Free the table we allocated */
468 tablep = iopte_deref(table, data);
469 __arm_lpae_free_pgtable(data, lvl + 1, tablep);
470 }
471 return 0; /* Bytes unmapped */
472 }
473 }
474
475 __arm_lpae_set_pte(ptep, table, cfg);
476 iova &= ~(blk_size - 1);
477 cfg->tlb->tlb_add_flush(iova, blk_size, true, data->iop.cookie);
478 return size;
479 }
480
__arm_lpae_unmap(struct arm_lpae_io_pgtable * data,unsigned long iova,size_t size,int lvl,arm_lpae_iopte * ptep)481 static int __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
482 unsigned long iova, size_t size, int lvl,
483 arm_lpae_iopte *ptep)
484 {
485 arm_lpae_iopte pte;
486 const struct iommu_gather_ops *tlb = data->iop.cfg.tlb;
487 void *cookie = data->iop.cookie;
488 size_t blk_size = ARM_LPAE_BLOCK_SIZE(lvl, data);
489
490 ptep += ARM_LPAE_LVL_IDX(iova, lvl, data);
491 pte = *ptep;
492
493 /* Something went horribly wrong and we ran out of page table */
494 if (WARN_ON(!pte || (lvl == ARM_LPAE_MAX_LEVELS)))
495 return 0;
496
497 /* If the size matches this level, we're in the right place */
498 if (size == blk_size) {
499 __arm_lpae_set_pte(ptep, 0, &data->iop.cfg);
500
501 if (!iopte_leaf(pte, lvl)) {
502 /* Also flush any partial walks */
503 tlb->tlb_add_flush(iova, size, false, cookie);
504 tlb->tlb_sync(cookie);
505 ptep = iopte_deref(pte, data);
506 __arm_lpae_free_pgtable(data, lvl + 1, ptep);
507 } else {
508 tlb->tlb_add_flush(iova, size, true, cookie);
509 }
510
511 return size;
512 } else if (iopte_leaf(pte, lvl)) {
513 /*
514 * Insert a table at the next level to map the old region,
515 * minus the part we want to unmap
516 */
517 return arm_lpae_split_blk_unmap(data, iova, size,
518 iopte_prot(pte), lvl, ptep,
519 blk_size);
520 }
521
522 /* Keep on walkin' */
523 ptep = iopte_deref(pte, data);
524 return __arm_lpae_unmap(data, iova, size, lvl + 1, ptep);
525 }
526
arm_lpae_unmap(struct io_pgtable_ops * ops,unsigned long iova,size_t size)527 static int arm_lpae_unmap(struct io_pgtable_ops *ops, unsigned long iova,
528 size_t size)
529 {
530 size_t unmapped;
531 struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
532 struct io_pgtable *iop = &data->iop;
533 arm_lpae_iopte *ptep = data->pgd;
534 int lvl = ARM_LPAE_START_LVL(data);
535
536 unmapped = __arm_lpae_unmap(data, iova, size, lvl, ptep);
537 if (unmapped)
538 iop->cfg.tlb->tlb_sync(iop->cookie);
539
540 return unmapped;
541 }
542
arm_lpae_iova_to_phys(struct io_pgtable_ops * ops,unsigned long iova)543 static phys_addr_t arm_lpae_iova_to_phys(struct io_pgtable_ops *ops,
544 unsigned long iova)
545 {
546 struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
547 arm_lpae_iopte pte, *ptep = data->pgd;
548 int lvl = ARM_LPAE_START_LVL(data);
549
550 do {
551 /* Valid IOPTE pointer? */
552 if (!ptep)
553 return 0;
554
555 /* Grab the IOPTE we're interested in */
556 pte = *(ptep + ARM_LPAE_LVL_IDX(iova, lvl, data));
557
558 /* Valid entry? */
559 if (!pte)
560 return 0;
561
562 /* Leaf entry? */
563 if (iopte_leaf(pte,lvl))
564 goto found_translation;
565
566 /* Take it to the next level */
567 ptep = iopte_deref(pte, data);
568 } while (++lvl < ARM_LPAE_MAX_LEVELS);
569
570 /* Ran out of page tables to walk */
571 return 0;
572
573 found_translation:
574 iova &= ((1 << data->pg_shift) - 1);
575 return ((phys_addr_t)iopte_to_pfn(pte,data) << data->pg_shift) | iova;
576 }
577
arm_lpae_restrict_pgsizes(struct io_pgtable_cfg * cfg)578 static void arm_lpae_restrict_pgsizes(struct io_pgtable_cfg *cfg)
579 {
580 unsigned long granule;
581
582 /*
583 * We need to restrict the supported page sizes to match the
584 * translation regime for a particular granule. Aim to match
585 * the CPU page size if possible, otherwise prefer smaller sizes.
586 * While we're at it, restrict the block sizes to match the
587 * chosen granule.
588 */
589 if (cfg->pgsize_bitmap & PAGE_SIZE)
590 granule = PAGE_SIZE;
591 else if (cfg->pgsize_bitmap & ~PAGE_MASK)
592 granule = 1UL << __fls(cfg->pgsize_bitmap & ~PAGE_MASK);
593 else if (cfg->pgsize_bitmap & PAGE_MASK)
594 granule = 1UL << __ffs(cfg->pgsize_bitmap & PAGE_MASK);
595 else
596 granule = 0;
597
598 switch (granule) {
599 case SZ_4K:
600 cfg->pgsize_bitmap &= (SZ_4K | SZ_2M | SZ_1G);
601 break;
602 case SZ_16K:
603 cfg->pgsize_bitmap &= (SZ_16K | SZ_32M);
604 break;
605 case SZ_64K:
606 cfg->pgsize_bitmap &= (SZ_64K | SZ_512M);
607 break;
608 default:
609 cfg->pgsize_bitmap = 0;
610 }
611 }
612
613 static struct arm_lpae_io_pgtable *
arm_lpae_alloc_pgtable(struct io_pgtable_cfg * cfg)614 arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg)
615 {
616 unsigned long va_bits, pgd_bits;
617 struct arm_lpae_io_pgtable *data;
618
619 arm_lpae_restrict_pgsizes(cfg);
620
621 if (!(cfg->pgsize_bitmap & (SZ_4K | SZ_16K | SZ_64K)))
622 return NULL;
623
624 if (cfg->ias > ARM_LPAE_MAX_ADDR_BITS)
625 return NULL;
626
627 if (cfg->oas > ARM_LPAE_MAX_ADDR_BITS)
628 return NULL;
629
630 if (!selftest_running && cfg->iommu_dev->dma_pfn_offset) {
631 dev_err(cfg->iommu_dev, "Cannot accommodate DMA offset for IOMMU page tables\n");
632 return NULL;
633 }
634
635 data = kmalloc(sizeof(*data), GFP_KERNEL);
636 if (!data)
637 return NULL;
638
639 data->pg_shift = __ffs(cfg->pgsize_bitmap);
640 data->bits_per_level = data->pg_shift - ilog2(sizeof(arm_lpae_iopte));
641
642 va_bits = cfg->ias - data->pg_shift;
643 data->levels = DIV_ROUND_UP(va_bits, data->bits_per_level);
644
645 /* Calculate the actual size of our pgd (without concatenation) */
646 pgd_bits = va_bits - (data->bits_per_level * (data->levels - 1));
647 data->pgd_size = 1UL << (pgd_bits + ilog2(sizeof(arm_lpae_iopte)));
648
649 data->iop.ops = (struct io_pgtable_ops) {
650 .map = arm_lpae_map,
651 .unmap = arm_lpae_unmap,
652 .iova_to_phys = arm_lpae_iova_to_phys,
653 };
654
655 return data;
656 }
657
658 static struct io_pgtable *
arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg * cfg,void * cookie)659 arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie)
660 {
661 u64 reg;
662 struct arm_lpae_io_pgtable *data = arm_lpae_alloc_pgtable(cfg);
663
664 if (!data)
665 return NULL;
666
667 /* TCR */
668 reg = (ARM_LPAE_TCR_SH_IS << ARM_LPAE_TCR_SH0_SHIFT) |
669 (ARM_LPAE_TCR_RGN_WBWA << ARM_LPAE_TCR_IRGN0_SHIFT) |
670 (ARM_LPAE_TCR_RGN_WBWA << ARM_LPAE_TCR_ORGN0_SHIFT);
671
672 switch (1 << data->pg_shift) {
673 case SZ_4K:
674 reg |= ARM_LPAE_TCR_TG0_4K;
675 break;
676 case SZ_16K:
677 reg |= ARM_LPAE_TCR_TG0_16K;
678 break;
679 case SZ_64K:
680 reg |= ARM_LPAE_TCR_TG0_64K;
681 break;
682 }
683
684 switch (cfg->oas) {
685 case 32:
686 reg |= (ARM_LPAE_TCR_PS_32_BIT << ARM_LPAE_TCR_IPS_SHIFT);
687 break;
688 case 36:
689 reg |= (ARM_LPAE_TCR_PS_36_BIT << ARM_LPAE_TCR_IPS_SHIFT);
690 break;
691 case 40:
692 reg |= (ARM_LPAE_TCR_PS_40_BIT << ARM_LPAE_TCR_IPS_SHIFT);
693 break;
694 case 42:
695 reg |= (ARM_LPAE_TCR_PS_42_BIT << ARM_LPAE_TCR_IPS_SHIFT);
696 break;
697 case 44:
698 reg |= (ARM_LPAE_TCR_PS_44_BIT << ARM_LPAE_TCR_IPS_SHIFT);
699 break;
700 case 48:
701 reg |= (ARM_LPAE_TCR_PS_48_BIT << ARM_LPAE_TCR_IPS_SHIFT);
702 break;
703 default:
704 goto out_free_data;
705 }
706
707 reg |= (64ULL - cfg->ias) << ARM_LPAE_TCR_T0SZ_SHIFT;
708
709 /* Disable speculative walks through TTBR1 */
710 reg |= ARM_LPAE_TCR_EPD1;
711 cfg->arm_lpae_s1_cfg.tcr = reg;
712
713 /* MAIRs */
714 reg = (ARM_LPAE_MAIR_ATTR_NC
715 << ARM_LPAE_MAIR_ATTR_SHIFT(ARM_LPAE_MAIR_ATTR_IDX_NC)) |
716 (ARM_LPAE_MAIR_ATTR_WBRWA
717 << ARM_LPAE_MAIR_ATTR_SHIFT(ARM_LPAE_MAIR_ATTR_IDX_CACHE)) |
718 (ARM_LPAE_MAIR_ATTR_DEVICE
719 << ARM_LPAE_MAIR_ATTR_SHIFT(ARM_LPAE_MAIR_ATTR_IDX_DEV));
720
721 cfg->arm_lpae_s1_cfg.mair[0] = reg;
722 cfg->arm_lpae_s1_cfg.mair[1] = 0;
723
724 /* Looking good; allocate a pgd */
725 data->pgd = __arm_lpae_alloc_pages(data->pgd_size, GFP_KERNEL, cfg);
726 if (!data->pgd)
727 goto out_free_data;
728
729 /* Ensure the empty pgd is visible before any actual TTBR write */
730 wmb();
731
732 /* TTBRs */
733 cfg->arm_lpae_s1_cfg.ttbr[0] = virt_to_phys(data->pgd);
734 cfg->arm_lpae_s1_cfg.ttbr[1] = 0;
735 return &data->iop;
736
737 out_free_data:
738 kfree(data);
739 return NULL;
740 }
741
742 static struct io_pgtable *
arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg * cfg,void * cookie)743 arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie)
744 {
745 u64 reg, sl;
746 struct arm_lpae_io_pgtable *data = arm_lpae_alloc_pgtable(cfg);
747
748 if (!data)
749 return NULL;
750
751 /*
752 * Concatenate PGDs at level 1 if possible in order to reduce
753 * the depth of the stage-2 walk.
754 */
755 if (data->levels == ARM_LPAE_MAX_LEVELS) {
756 unsigned long pgd_pages;
757
758 pgd_pages = data->pgd_size >> ilog2(sizeof(arm_lpae_iopte));
759 if (pgd_pages <= ARM_LPAE_S2_MAX_CONCAT_PAGES) {
760 data->pgd_size = pgd_pages << data->pg_shift;
761 data->levels--;
762 }
763 }
764
765 /* VTCR */
766 reg = ARM_64_LPAE_S2_TCR_RES1 |
767 (ARM_LPAE_TCR_SH_IS << ARM_LPAE_TCR_SH0_SHIFT) |
768 (ARM_LPAE_TCR_RGN_WBWA << ARM_LPAE_TCR_IRGN0_SHIFT) |
769 (ARM_LPAE_TCR_RGN_WBWA << ARM_LPAE_TCR_ORGN0_SHIFT);
770
771 sl = ARM_LPAE_START_LVL(data);
772
773 switch (1 << data->pg_shift) {
774 case SZ_4K:
775 reg |= ARM_LPAE_TCR_TG0_4K;
776 sl++; /* SL0 format is different for 4K granule size */
777 break;
778 case SZ_16K:
779 reg |= ARM_LPAE_TCR_TG0_16K;
780 break;
781 case SZ_64K:
782 reg |= ARM_LPAE_TCR_TG0_64K;
783 break;
784 }
785
786 switch (cfg->oas) {
787 case 32:
788 reg |= (ARM_LPAE_TCR_PS_32_BIT << ARM_LPAE_TCR_PS_SHIFT);
789 break;
790 case 36:
791 reg |= (ARM_LPAE_TCR_PS_36_BIT << ARM_LPAE_TCR_PS_SHIFT);
792 break;
793 case 40:
794 reg |= (ARM_LPAE_TCR_PS_40_BIT << ARM_LPAE_TCR_PS_SHIFT);
795 break;
796 case 42:
797 reg |= (ARM_LPAE_TCR_PS_42_BIT << ARM_LPAE_TCR_PS_SHIFT);
798 break;
799 case 44:
800 reg |= (ARM_LPAE_TCR_PS_44_BIT << ARM_LPAE_TCR_PS_SHIFT);
801 break;
802 case 48:
803 reg |= (ARM_LPAE_TCR_PS_48_BIT << ARM_LPAE_TCR_PS_SHIFT);
804 break;
805 default:
806 goto out_free_data;
807 }
808
809 reg |= (64ULL - cfg->ias) << ARM_LPAE_TCR_T0SZ_SHIFT;
810 reg |= (~sl & ARM_LPAE_TCR_SL0_MASK) << ARM_LPAE_TCR_SL0_SHIFT;
811 cfg->arm_lpae_s2_cfg.vtcr = reg;
812
813 /* Allocate pgd pages */
814 data->pgd = __arm_lpae_alloc_pages(data->pgd_size, GFP_KERNEL, cfg);
815 if (!data->pgd)
816 goto out_free_data;
817
818 /* Ensure the empty pgd is visible before any actual TTBR write */
819 wmb();
820
821 /* VTTBR */
822 cfg->arm_lpae_s2_cfg.vttbr = virt_to_phys(data->pgd);
823 return &data->iop;
824
825 out_free_data:
826 kfree(data);
827 return NULL;
828 }
829
830 static struct io_pgtable *
arm_32_lpae_alloc_pgtable_s1(struct io_pgtable_cfg * cfg,void * cookie)831 arm_32_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie)
832 {
833 struct io_pgtable *iop;
834
835 if (cfg->ias > 32 || cfg->oas > 40)
836 return NULL;
837
838 cfg->pgsize_bitmap &= (SZ_4K | SZ_2M | SZ_1G);
839 iop = arm_64_lpae_alloc_pgtable_s1(cfg, cookie);
840 if (iop) {
841 cfg->arm_lpae_s1_cfg.tcr |= ARM_32_LPAE_TCR_EAE;
842 cfg->arm_lpae_s1_cfg.tcr &= 0xffffffff;
843 }
844
845 return iop;
846 }
847
848 static struct io_pgtable *
arm_32_lpae_alloc_pgtable_s2(struct io_pgtable_cfg * cfg,void * cookie)849 arm_32_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie)
850 {
851 struct io_pgtable *iop;
852
853 if (cfg->ias > 40 || cfg->oas > 40)
854 return NULL;
855
856 cfg->pgsize_bitmap &= (SZ_4K | SZ_2M | SZ_1G);
857 iop = arm_64_lpae_alloc_pgtable_s2(cfg, cookie);
858 if (iop)
859 cfg->arm_lpae_s2_cfg.vtcr &= 0xffffffff;
860
861 return iop;
862 }
863
864 struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns = {
865 .alloc = arm_64_lpae_alloc_pgtable_s1,
866 .free = arm_lpae_free_pgtable,
867 };
868
869 struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns = {
870 .alloc = arm_64_lpae_alloc_pgtable_s2,
871 .free = arm_lpae_free_pgtable,
872 };
873
874 struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns = {
875 .alloc = arm_32_lpae_alloc_pgtable_s1,
876 .free = arm_lpae_free_pgtable,
877 };
878
879 struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns = {
880 .alloc = arm_32_lpae_alloc_pgtable_s2,
881 .free = arm_lpae_free_pgtable,
882 };
883
884 #ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE_SELFTEST
885
886 static struct io_pgtable_cfg *cfg_cookie;
887
dummy_tlb_flush_all(void * cookie)888 static void dummy_tlb_flush_all(void *cookie)
889 {
890 WARN_ON(cookie != cfg_cookie);
891 }
892
dummy_tlb_add_flush(unsigned long iova,size_t size,bool leaf,void * cookie)893 static void dummy_tlb_add_flush(unsigned long iova, size_t size, bool leaf,
894 void *cookie)
895 {
896 WARN_ON(cookie != cfg_cookie);
897 WARN_ON(!(size & cfg_cookie->pgsize_bitmap));
898 }
899
dummy_tlb_sync(void * cookie)900 static void dummy_tlb_sync(void *cookie)
901 {
902 WARN_ON(cookie != cfg_cookie);
903 }
904
905 static struct iommu_gather_ops dummy_tlb_ops __initdata = {
906 .tlb_flush_all = dummy_tlb_flush_all,
907 .tlb_add_flush = dummy_tlb_add_flush,
908 .tlb_sync = dummy_tlb_sync,
909 };
910
arm_lpae_dump_ops(struct io_pgtable_ops * ops)911 static void __init arm_lpae_dump_ops(struct io_pgtable_ops *ops)
912 {
913 struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
914 struct io_pgtable_cfg *cfg = &data->iop.cfg;
915
916 pr_err("cfg: pgsize_bitmap 0x%lx, ias %u-bit\n",
917 cfg->pgsize_bitmap, cfg->ias);
918 pr_err("data: %d levels, 0x%zx pgd_size, %lu pg_shift, %lu bits_per_level, pgd @ %p\n",
919 data->levels, data->pgd_size, data->pg_shift,
920 data->bits_per_level, data->pgd);
921 }
922
923 #define __FAIL(ops, i) ({ \
924 WARN(1, "selftest: test failed for fmt idx %d\n", (i)); \
925 arm_lpae_dump_ops(ops); \
926 selftest_running = false; \
927 -EFAULT; \
928 })
929
arm_lpae_run_tests(struct io_pgtable_cfg * cfg)930 static int __init arm_lpae_run_tests(struct io_pgtable_cfg *cfg)
931 {
932 static const enum io_pgtable_fmt fmts[] = {
933 ARM_64_LPAE_S1,
934 ARM_64_LPAE_S2,
935 };
936
937 int i, j;
938 unsigned long iova;
939 size_t size;
940 struct io_pgtable_ops *ops;
941
942 selftest_running = true;
943
944 for (i = 0; i < ARRAY_SIZE(fmts); ++i) {
945 cfg_cookie = cfg;
946 ops = alloc_io_pgtable_ops(fmts[i], cfg, cfg);
947 if (!ops) {
948 pr_err("selftest: failed to allocate io pgtable ops\n");
949 return -ENOMEM;
950 }
951
952 /*
953 * Initial sanity checks.
954 * Empty page tables shouldn't provide any translations.
955 */
956 if (ops->iova_to_phys(ops, 42))
957 return __FAIL(ops, i);
958
959 if (ops->iova_to_phys(ops, SZ_1G + 42))
960 return __FAIL(ops, i);
961
962 if (ops->iova_to_phys(ops, SZ_2G + 42))
963 return __FAIL(ops, i);
964
965 /*
966 * Distinct mappings of different granule sizes.
967 */
968 iova = 0;
969 j = find_first_bit(&cfg->pgsize_bitmap, BITS_PER_LONG);
970 while (j != BITS_PER_LONG) {
971 size = 1UL << j;
972
973 if (ops->map(ops, iova, iova, size, IOMMU_READ |
974 IOMMU_WRITE |
975 IOMMU_NOEXEC |
976 IOMMU_CACHE))
977 return __FAIL(ops, i);
978
979 /* Overlapping mappings */
980 if (!ops->map(ops, iova, iova + size, size,
981 IOMMU_READ | IOMMU_NOEXEC))
982 return __FAIL(ops, i);
983
984 if (ops->iova_to_phys(ops, iova + 42) != (iova + 42))
985 return __FAIL(ops, i);
986
987 iova += SZ_1G;
988 j++;
989 j = find_next_bit(&cfg->pgsize_bitmap, BITS_PER_LONG, j);
990 }
991
992 /* Partial unmap */
993 size = 1UL << __ffs(cfg->pgsize_bitmap);
994 if (ops->unmap(ops, SZ_1G + size, size) != size)
995 return __FAIL(ops, i);
996
997 /* Remap of partial unmap */
998 if (ops->map(ops, SZ_1G + size, size, size, IOMMU_READ))
999 return __FAIL(ops, i);
1000
1001 if (ops->iova_to_phys(ops, SZ_1G + size + 42) != (size + 42))
1002 return __FAIL(ops, i);
1003
1004 /* Full unmap */
1005 iova = 0;
1006 j = find_first_bit(&cfg->pgsize_bitmap, BITS_PER_LONG);
1007 while (j != BITS_PER_LONG) {
1008 size = 1UL << j;
1009
1010 if (ops->unmap(ops, iova, size) != size)
1011 return __FAIL(ops, i);
1012
1013 if (ops->iova_to_phys(ops, iova + 42))
1014 return __FAIL(ops, i);
1015
1016 /* Remap full block */
1017 if (ops->map(ops, iova, iova, size, IOMMU_WRITE))
1018 return __FAIL(ops, i);
1019
1020 if (ops->iova_to_phys(ops, iova + 42) != (iova + 42))
1021 return __FAIL(ops, i);
1022
1023 iova += SZ_1G;
1024 j++;
1025 j = find_next_bit(&cfg->pgsize_bitmap, BITS_PER_LONG, j);
1026 }
1027
1028 free_io_pgtable_ops(ops);
1029 }
1030
1031 selftest_running = false;
1032 return 0;
1033 }
1034
arm_lpae_do_selftests(void)1035 static int __init arm_lpae_do_selftests(void)
1036 {
1037 static const unsigned long pgsize[] = {
1038 SZ_4K | SZ_2M | SZ_1G,
1039 SZ_16K | SZ_32M,
1040 SZ_64K | SZ_512M,
1041 };
1042
1043 static const unsigned int ias[] = {
1044 32, 36, 40, 42, 44, 48,
1045 };
1046
1047 int i, j, pass = 0, fail = 0;
1048 struct io_pgtable_cfg cfg = {
1049 .tlb = &dummy_tlb_ops,
1050 .oas = 48,
1051 };
1052
1053 for (i = 0; i < ARRAY_SIZE(pgsize); ++i) {
1054 for (j = 0; j < ARRAY_SIZE(ias); ++j) {
1055 cfg.pgsize_bitmap = pgsize[i];
1056 cfg.ias = ias[j];
1057 pr_info("selftest: pgsize_bitmap 0x%08lx, IAS %u\n",
1058 pgsize[i], ias[j]);
1059 if (arm_lpae_run_tests(&cfg))
1060 fail++;
1061 else
1062 pass++;
1063 }
1064 }
1065
1066 pr_info("selftest: completed with %d PASS %d FAIL\n", pass, fail);
1067 return fail ? -EFAULT : 0;
1068 }
1069 subsys_initcall(arm_lpae_do_selftests);
1070 #endif
1071