1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * CPU-agnostic ARM page table allocator.
4 *
5 * ARMv7 Short-descriptor format, supporting
6 * - Basic memory attributes
7 * - Simplified access permissions (AP[2:1] model)
8 * - Backwards-compatible TEX remap
9 * - Large pages/supersections (if indicated by the caller)
10 *
11 * Not supporting:
12 * - Legacy access permissions (AP[2:0] model)
13 *
14 * Almost certainly never supporting:
15 * - PXN
16 * - Domains
17 *
18 * Copyright (C) 2014-2015 ARM Limited
19 * Copyright (c) 2014-2015 MediaTek Inc.
20 */
21
22#define pr_fmt(fmt) "arm-v7s io-pgtable: " fmt
23
24#include <linux/atomic.h>
25#include <linux/dma-mapping.h>
26#include <linux/gfp.h>
27#include <linux/io-pgtable.h>
28#include <linux/iommu.h>
29#include <linux/kernel.h>
30#include <linux/kmemleak.h>
31#include <linux/sizes.h>
32#include <linux/slab.h>
33#include <linux/spinlock.h>
34#include <linux/types.h>
35
36#include <asm/barrier.h>
37
38/* Struct accessors */
39#define io_pgtable_to_data(x) \
40 container_of((x), struct arm_v7s_io_pgtable, iop)
41
42#define io_pgtable_ops_to_data(x) \
43 io_pgtable_to_data(io_pgtable_ops_to_pgtable(x))
44
45/*
46 * We have 32 bits total; 12 bits resolved at level 1, 8 bits at level 2,
47 * and 12 bits in a page.
48 * MediaTek extend 2 bits to reach 34bits, 14 bits at lvl1 and 8 bits at lvl2.
49 */
50#define ARM_V7S_ADDR_BITS 32
51#define _ARM_V7S_LVL_BITS(lvl, cfg) ((lvl) == 1 ? ((cfg)->ias - 20) : 8)
52#define ARM_V7S_LVL_SHIFT(lvl) ((lvl) == 1 ? 20 : 12)
53#define ARM_V7S_TABLE_SHIFT 10
54
55#define ARM_V7S_PTES_PER_LVL(lvl, cfg) (1 << _ARM_V7S_LVL_BITS(lvl, cfg))
56#define ARM_V7S_TABLE_SIZE(lvl, cfg) \
57 (ARM_V7S_PTES_PER_LVL(lvl, cfg) * sizeof(arm_v7s_iopte))
58
59#define ARM_V7S_BLOCK_SIZE(lvl) (1UL << ARM_V7S_LVL_SHIFT(lvl))
60#define ARM_V7S_LVL_MASK(lvl) ((u32)(~0U << ARM_V7S_LVL_SHIFT(lvl)))
61#define ARM_V7S_TABLE_MASK ((u32)(~0U << ARM_V7S_TABLE_SHIFT))
62#define _ARM_V7S_IDX_MASK(lvl, cfg) (ARM_V7S_PTES_PER_LVL(lvl, cfg) - 1)
63#define ARM_V7S_LVL_IDX(addr, lvl, cfg) ({ \
64 int _l = lvl; \
65 ((addr) >> ARM_V7S_LVL_SHIFT(_l)) & _ARM_V7S_IDX_MASK(_l, cfg); \
66})
67
68/*
69 * Large page/supersection entries are effectively a block of 16 page/section
70 * entries, along the lines of the LPAE contiguous hint, but all with the
71 * same output address. For want of a better common name we'll call them
72 * "contiguous" versions of their respective page/section entries here, but
73 * noting the distinction (WRT to TLB maintenance) that they represent *one*
74 * entry repeated 16 times, not 16 separate entries (as in the LPAE case).
75 */
76#define ARM_V7S_CONT_PAGES 16
77
78/* PTE type bits: these are all mixed up with XN/PXN bits in most cases */
79#define ARM_V7S_PTE_TYPE_TABLE 0x1
80#define ARM_V7S_PTE_TYPE_PAGE 0x2
81#define ARM_V7S_PTE_TYPE_CONT_PAGE 0x1
82
83#define ARM_V7S_PTE_IS_VALID(pte) (((pte) & 0x3) != 0)
84#define ARM_V7S_PTE_IS_TABLE(pte, lvl) \
85 ((lvl) == 1 && (((pte) & 0x3) == ARM_V7S_PTE_TYPE_TABLE))
86
87/* Page table bits */
88#define ARM_V7S_ATTR_XN(lvl) BIT(4 * (2 - (lvl)))
89#define ARM_V7S_ATTR_B BIT(2)
90#define ARM_V7S_ATTR_C BIT(3)
91#define ARM_V7S_ATTR_NS_TABLE BIT(3)
92#define ARM_V7S_ATTR_NS_SECTION BIT(19)
93
94#define ARM_V7S_CONT_SECTION BIT(18)
95#define ARM_V7S_CONT_PAGE_XN_SHIFT 15
96
97/*
98 * The attribute bits are consistently ordered*, but occupy bits [17:10] of
99 * a level 1 PTE vs. bits [11:4] at level 2. Thus we define the individual
100 * fields relative to that 8-bit block, plus a total shift relative to the PTE.
101 */
102#define ARM_V7S_ATTR_SHIFT(lvl) (16 - (lvl) * 6)
103
104#define ARM_V7S_ATTR_MASK 0xff
105#define ARM_V7S_ATTR_AP0 BIT(0)
106#define ARM_V7S_ATTR_AP1 BIT(1)
107#define ARM_V7S_ATTR_AP2 BIT(5)
108#define ARM_V7S_ATTR_S BIT(6)
109#define ARM_V7S_ATTR_NG BIT(7)
110#define ARM_V7S_TEX_SHIFT 2
111#define ARM_V7S_TEX_MASK 0x7
112#define ARM_V7S_ATTR_TEX(val) (((val) & ARM_V7S_TEX_MASK) << ARM_V7S_TEX_SHIFT)
113
114/* MediaTek extend the bits below for PA 32bit/33bit/34bit */
115#define ARM_V7S_ATTR_MTK_PA_BIT32 BIT(9)
116#define ARM_V7S_ATTR_MTK_PA_BIT33 BIT(4)
117#define ARM_V7S_ATTR_MTK_PA_BIT34 BIT(5)
118
119/* *well, except for TEX on level 2 large pages, of course :( */
120#define ARM_V7S_CONT_PAGE_TEX_SHIFT 6
121#define ARM_V7S_CONT_PAGE_TEX_MASK (ARM_V7S_TEX_MASK << ARM_V7S_CONT_PAGE_TEX_SHIFT)
122
123/* Simplified access permissions */
124#define ARM_V7S_PTE_AF ARM_V7S_ATTR_AP0
125#define ARM_V7S_PTE_AP_UNPRIV ARM_V7S_ATTR_AP1
126#define ARM_V7S_PTE_AP_RDONLY ARM_V7S_ATTR_AP2
127
128/* Register bits */
129#define ARM_V7S_RGN_NC 0
130#define ARM_V7S_RGN_WBWA 1
131#define ARM_V7S_RGN_WT 2
132#define ARM_V7S_RGN_WB 3
133
134#define ARM_V7S_PRRR_TYPE_DEVICE 1
135#define ARM_V7S_PRRR_TYPE_NORMAL 2
136#define ARM_V7S_PRRR_TR(n, type) (((type) & 0x3) << ((n) * 2))
137#define ARM_V7S_PRRR_DS0 BIT(16)
138#define ARM_V7S_PRRR_DS1 BIT(17)
139#define ARM_V7S_PRRR_NS0 BIT(18)
140#define ARM_V7S_PRRR_NS1 BIT(19)
141#define ARM_V7S_PRRR_NOS(n) BIT((n) + 24)
142
143#define ARM_V7S_NMRR_IR(n, attr) (((attr) & 0x3) << ((n) * 2))
144#define ARM_V7S_NMRR_OR(n, attr) (((attr) & 0x3) << ((n) * 2 + 16))
145
146#define ARM_V7S_TTBR_S BIT(1)
147#define ARM_V7S_TTBR_NOS BIT(5)
148#define ARM_V7S_TTBR_ORGN_ATTR(attr) (((attr) & 0x3) << 3)
149#define ARM_V7S_TTBR_IRGN_ATTR(attr) \
150 ((((attr) & 0x1) << 6) | (((attr) & 0x2) >> 1))
151
152#ifdef CONFIG_ZONE_DMA32
153#define ARM_V7S_TABLE_GFP_DMA GFP_DMA32
154#define ARM_V7S_TABLE_SLAB_FLAGS SLAB_CACHE_DMA32
155#else
156#define ARM_V7S_TABLE_GFP_DMA GFP_DMA
157#define ARM_V7S_TABLE_SLAB_FLAGS SLAB_CACHE_DMA
158#endif
159
160typedef u32 arm_v7s_iopte;
161
162static bool selftest_running;
163
164struct arm_v7s_io_pgtable {
165 struct io_pgtable iop;
166
167 arm_v7s_iopte *pgd;
168 struct kmem_cache *l2_tables;
169 spinlock_t split_lock;
170};
171
172static bool arm_v7s_pte_is_cont(arm_v7s_iopte pte, int lvl);
173
174static dma_addr_t __arm_v7s_dma_addr(void *pages)
175{
176 return (dma_addr_t)virt_to_phys(address: pages);
177}
178
179static bool arm_v7s_is_mtk_enabled(struct io_pgtable_cfg *cfg)
180{
181 return IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT) &&
182 (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_EXT);
183}
184
185static arm_v7s_iopte to_mtk_iopte(phys_addr_t paddr, arm_v7s_iopte pte)
186{
187 if (paddr & BIT_ULL(32))
188 pte |= ARM_V7S_ATTR_MTK_PA_BIT32;
189 if (paddr & BIT_ULL(33))
190 pte |= ARM_V7S_ATTR_MTK_PA_BIT33;
191 if (paddr & BIT_ULL(34))
192 pte |= ARM_V7S_ATTR_MTK_PA_BIT34;
193 return pte;
194}
195
196static arm_v7s_iopte paddr_to_iopte(phys_addr_t paddr, int lvl,
197 struct io_pgtable_cfg *cfg)
198{
199 arm_v7s_iopte pte = paddr & ARM_V7S_LVL_MASK(lvl);
200
201 if (arm_v7s_is_mtk_enabled(cfg))
202 return to_mtk_iopte(paddr, pte);
203
204 return pte;
205}
206
207static phys_addr_t iopte_to_paddr(arm_v7s_iopte pte, int lvl,
208 struct io_pgtable_cfg *cfg)
209{
210 arm_v7s_iopte mask;
211 phys_addr_t paddr;
212
213 if (ARM_V7S_PTE_IS_TABLE(pte, lvl))
214 mask = ARM_V7S_TABLE_MASK;
215 else if (arm_v7s_pte_is_cont(pte, lvl))
216 mask = ARM_V7S_LVL_MASK(lvl) * ARM_V7S_CONT_PAGES;
217 else
218 mask = ARM_V7S_LVL_MASK(lvl);
219
220 paddr = pte & mask;
221 if (!arm_v7s_is_mtk_enabled(cfg))
222 return paddr;
223
224 if (pte & ARM_V7S_ATTR_MTK_PA_BIT32)
225 paddr |= BIT_ULL(32);
226 if (pte & ARM_V7S_ATTR_MTK_PA_BIT33)
227 paddr |= BIT_ULL(33);
228 if (pte & ARM_V7S_ATTR_MTK_PA_BIT34)
229 paddr |= BIT_ULL(34);
230 return paddr;
231}
232
233static arm_v7s_iopte *iopte_deref(arm_v7s_iopte pte, int lvl,
234 struct arm_v7s_io_pgtable *data)
235{
236 return phys_to_virt(address: iopte_to_paddr(pte, lvl, cfg: &data->iop.cfg));
237}
238
239static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp,
240 struct arm_v7s_io_pgtable *data)
241{
242 struct io_pgtable_cfg *cfg = &data->iop.cfg;
243 struct device *dev = cfg->iommu_dev;
244 phys_addr_t phys;
245 dma_addr_t dma;
246 size_t size = ARM_V7S_TABLE_SIZE(lvl, cfg);
247 void *table = NULL;
248 gfp_t gfp_l1;
249
250 /*
251 * ARM_MTK_TTBR_EXT extend the translation table base support larger
252 * memory address.
253 */
254 gfp_l1 = cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT ?
255 GFP_KERNEL : ARM_V7S_TABLE_GFP_DMA;
256
257 if (lvl == 1)
258 table = (void *)__get_free_pages(gfp_mask: gfp_l1 | __GFP_ZERO, order: get_order(size));
259 else if (lvl == 2)
260 table = kmem_cache_zalloc(k: data->l2_tables, flags: gfp);
261
262 if (!table)
263 return NULL;
264
265 phys = virt_to_phys(address: table);
266 if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT ?
267 phys >= (1ULL << cfg->oas) : phys != (arm_v7s_iopte)phys) {
268 /* Doesn't fit in PTE */
269 dev_err(dev, "Page table does not fit in PTE: %pa", &phys);
270 goto out_free;
271 }
272 if (!cfg->coherent_walk) {
273 dma = dma_map_single(dev, table, size, DMA_TO_DEVICE);
274 if (dma_mapping_error(dev, dma_addr: dma))
275 goto out_free;
276 /*
277 * We depend on the IOMMU being able to work with any physical
278 * address directly, so if the DMA layer suggests otherwise by
279 * translating or truncating them, that bodes very badly...
280 */
281 if (dma != phys)
282 goto out_unmap;
283 }
284 if (lvl == 2)
285 kmemleak_ignore(ptr: table);
286 return table;
287
288out_unmap:
289 dev_err(dev, "Cannot accommodate DMA translation for IOMMU page tables\n");
290 dma_unmap_single(dev, dma, size, DMA_TO_DEVICE);
291out_free:
292 if (lvl == 1)
293 free_pages(addr: (unsigned long)table, order: get_order(size));
294 else
295 kmem_cache_free(s: data->l2_tables, objp: table);
296 return NULL;
297}
298
299static void __arm_v7s_free_table(void *table, int lvl,
300 struct arm_v7s_io_pgtable *data)
301{
302 struct io_pgtable_cfg *cfg = &data->iop.cfg;
303 struct device *dev = cfg->iommu_dev;
304 size_t size = ARM_V7S_TABLE_SIZE(lvl, cfg);
305
306 if (!cfg->coherent_walk)
307 dma_unmap_single(dev, __arm_v7s_dma_addr(table), size,
308 DMA_TO_DEVICE);
309 if (lvl == 1)
310 free_pages(addr: (unsigned long)table, order: get_order(size));
311 else
312 kmem_cache_free(s: data->l2_tables, objp: table);
313}
314
315static void __arm_v7s_pte_sync(arm_v7s_iopte *ptep, int num_entries,
316 struct io_pgtable_cfg *cfg)
317{
318 if (cfg->coherent_walk)
319 return;
320
321 dma_sync_single_for_device(dev: cfg->iommu_dev, addr: __arm_v7s_dma_addr(pages: ptep),
322 size: num_entries * sizeof(*ptep), dir: DMA_TO_DEVICE);
323}
324static void __arm_v7s_set_pte(arm_v7s_iopte *ptep, arm_v7s_iopte pte,
325 int num_entries, struct io_pgtable_cfg *cfg)
326{
327 int i;
328
329 for (i = 0; i < num_entries; i++)
330 ptep[i] = pte;
331
332 __arm_v7s_pte_sync(ptep, num_entries, cfg);
333}
334
335static arm_v7s_iopte arm_v7s_prot_to_pte(int prot, int lvl,
336 struct io_pgtable_cfg *cfg)
337{
338 bool ap = !(cfg->quirks & IO_PGTABLE_QUIRK_NO_PERMS);
339 arm_v7s_iopte pte = ARM_V7S_ATTR_NG | ARM_V7S_ATTR_S;
340
341 if (!(prot & IOMMU_MMIO))
342 pte |= ARM_V7S_ATTR_TEX(1);
343 if (ap) {
344 pte |= ARM_V7S_PTE_AF;
345 if (!(prot & IOMMU_PRIV))
346 pte |= ARM_V7S_PTE_AP_UNPRIV;
347 if (!(prot & IOMMU_WRITE))
348 pte |= ARM_V7S_PTE_AP_RDONLY;
349 }
350 pte <<= ARM_V7S_ATTR_SHIFT(lvl);
351
352 if ((prot & IOMMU_NOEXEC) && ap)
353 pte |= ARM_V7S_ATTR_XN(lvl);
354 if (prot & IOMMU_MMIO)
355 pte |= ARM_V7S_ATTR_B;
356 else if (prot & IOMMU_CACHE)
357 pte |= ARM_V7S_ATTR_B | ARM_V7S_ATTR_C;
358
359 pte |= ARM_V7S_PTE_TYPE_PAGE;
360 if (lvl == 1 && (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS))
361 pte |= ARM_V7S_ATTR_NS_SECTION;
362
363 return pte;
364}
365
366static int arm_v7s_pte_to_prot(arm_v7s_iopte pte, int lvl)
367{
368 int prot = IOMMU_READ;
369 arm_v7s_iopte attr = pte >> ARM_V7S_ATTR_SHIFT(lvl);
370
371 if (!(attr & ARM_V7S_PTE_AP_RDONLY))
372 prot |= IOMMU_WRITE;
373 if (!(attr & ARM_V7S_PTE_AP_UNPRIV))
374 prot |= IOMMU_PRIV;
375 if ((attr & (ARM_V7S_TEX_MASK << ARM_V7S_TEX_SHIFT)) == 0)
376 prot |= IOMMU_MMIO;
377 else if (pte & ARM_V7S_ATTR_C)
378 prot |= IOMMU_CACHE;
379 if (pte & ARM_V7S_ATTR_XN(lvl))
380 prot |= IOMMU_NOEXEC;
381
382 return prot;
383}
384
385static arm_v7s_iopte arm_v7s_pte_to_cont(arm_v7s_iopte pte, int lvl)
386{
387 if (lvl == 1) {
388 pte |= ARM_V7S_CONT_SECTION;
389 } else if (lvl == 2) {
390 arm_v7s_iopte xn = pte & ARM_V7S_ATTR_XN(lvl);
391 arm_v7s_iopte tex = pte & ARM_V7S_CONT_PAGE_TEX_MASK;
392
393 pte ^= xn | tex | ARM_V7S_PTE_TYPE_PAGE;
394 pte |= (xn << ARM_V7S_CONT_PAGE_XN_SHIFT) |
395 (tex << ARM_V7S_CONT_PAGE_TEX_SHIFT) |
396 ARM_V7S_PTE_TYPE_CONT_PAGE;
397 }
398 return pte;
399}
400
401static arm_v7s_iopte arm_v7s_cont_to_pte(arm_v7s_iopte pte, int lvl)
402{
403 if (lvl == 1) {
404 pte &= ~ARM_V7S_CONT_SECTION;
405 } else if (lvl == 2) {
406 arm_v7s_iopte xn = pte & BIT(ARM_V7S_CONT_PAGE_XN_SHIFT);
407 arm_v7s_iopte tex = pte & (ARM_V7S_CONT_PAGE_TEX_MASK <<
408 ARM_V7S_CONT_PAGE_TEX_SHIFT);
409
410 pte ^= xn | tex | ARM_V7S_PTE_TYPE_CONT_PAGE;
411 pte |= (xn >> ARM_V7S_CONT_PAGE_XN_SHIFT) |
412 (tex >> ARM_V7S_CONT_PAGE_TEX_SHIFT) |
413 ARM_V7S_PTE_TYPE_PAGE;
414 }
415 return pte;
416}
417
418static bool arm_v7s_pte_is_cont(arm_v7s_iopte pte, int lvl)
419{
420 if (lvl == 1 && !ARM_V7S_PTE_IS_TABLE(pte, lvl))
421 return pte & ARM_V7S_CONT_SECTION;
422 else if (lvl == 2)
423 return !(pte & ARM_V7S_PTE_TYPE_PAGE);
424 return false;
425}
426
427static size_t __arm_v7s_unmap(struct arm_v7s_io_pgtable *,
428 struct iommu_iotlb_gather *, unsigned long,
429 size_t, int, arm_v7s_iopte *);
430
431static int arm_v7s_init_pte(struct arm_v7s_io_pgtable *data,
432 unsigned long iova, phys_addr_t paddr, int prot,
433 int lvl, int num_entries, arm_v7s_iopte *ptep)
434{
435 struct io_pgtable_cfg *cfg = &data->iop.cfg;
436 arm_v7s_iopte pte;
437 int i;
438
439 for (i = 0; i < num_entries; i++)
440 if (ARM_V7S_PTE_IS_TABLE(ptep[i], lvl)) {
441 /*
442 * We need to unmap and free the old table before
443 * overwriting it with a block entry.
444 */
445 arm_v7s_iopte *tblp;
446 size_t sz = ARM_V7S_BLOCK_SIZE(lvl);
447
448 tblp = ptep - ARM_V7S_LVL_IDX(iova, lvl, cfg);
449 if (WARN_ON(__arm_v7s_unmap(data, NULL, iova + i * sz,
450 sz, lvl, tblp) != sz))
451 return -EINVAL;
452 } else if (ptep[i]) {
453 /* We require an unmap first */
454 WARN_ON(!selftest_running);
455 return -EEXIST;
456 }
457
458 pte = arm_v7s_prot_to_pte(prot, lvl, cfg);
459 if (num_entries > 1)
460 pte = arm_v7s_pte_to_cont(pte, lvl);
461
462 pte |= paddr_to_iopte(paddr, lvl, cfg);
463
464 __arm_v7s_set_pte(ptep, pte, num_entries, cfg);
465 return 0;
466}
467
468static arm_v7s_iopte arm_v7s_install_table(arm_v7s_iopte *table,
469 arm_v7s_iopte *ptep,
470 arm_v7s_iopte curr,
471 struct io_pgtable_cfg *cfg)
472{
473 phys_addr_t phys = virt_to_phys(address: table);
474 arm_v7s_iopte old, new;
475
476 new = phys | ARM_V7S_PTE_TYPE_TABLE;
477
478 if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT)
479 new = to_mtk_iopte(paddr: phys, pte: new);
480
481 if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS)
482 new |= ARM_V7S_ATTR_NS_TABLE;
483
484 /*
485 * Ensure the table itself is visible before its PTE can be.
486 * Whilst we could get away with cmpxchg64_release below, this
487 * doesn't have any ordering semantics when !CONFIG_SMP.
488 */
489 dma_wmb();
490
491 old = cmpxchg_relaxed(ptep, curr, new);
492 __arm_v7s_pte_sync(ptep, num_entries: 1, cfg);
493
494 return old;
495}
496
497static int __arm_v7s_map(struct arm_v7s_io_pgtable *data, unsigned long iova,
498 phys_addr_t paddr, size_t size, int prot,
499 int lvl, arm_v7s_iopte *ptep, gfp_t gfp)
500{
501 struct io_pgtable_cfg *cfg = &data->iop.cfg;
502 arm_v7s_iopte pte, *cptep;
503 int num_entries = size >> ARM_V7S_LVL_SHIFT(lvl);
504
505 /* Find our entry at the current level */
506 ptep += ARM_V7S_LVL_IDX(iova, lvl, cfg);
507
508 /* If we can install a leaf entry at this level, then do so */
509 if (num_entries)
510 return arm_v7s_init_pte(data, iova, paddr, prot,
511 lvl, num_entries, ptep);
512
513 /* We can't allocate tables at the final level */
514 if (WARN_ON(lvl == 2))
515 return -EINVAL;
516
517 /* Grab a pointer to the next level */
518 pte = READ_ONCE(*ptep);
519 if (!pte) {
520 cptep = __arm_v7s_alloc_table(lvl: lvl + 1, gfp, data);
521 if (!cptep)
522 return -ENOMEM;
523
524 pte = arm_v7s_install_table(table: cptep, ptep, curr: 0, cfg);
525 if (pte)
526 __arm_v7s_free_table(table: cptep, lvl: lvl + 1, data);
527 } else {
528 /* We've no easy way of knowing if it's synced yet, so... */
529 __arm_v7s_pte_sync(ptep, num_entries: 1, cfg);
530 }
531
532 if (ARM_V7S_PTE_IS_TABLE(pte, lvl)) {
533 cptep = iopte_deref(pte, lvl, data);
534 } else if (pte) {
535 /* We require an unmap first */
536 WARN_ON(!selftest_running);
537 return -EEXIST;
538 }
539
540 /* Rinse, repeat */
541 return __arm_v7s_map(data, iova, paddr, size, prot, lvl: lvl + 1, ptep: cptep, gfp);
542}
543
544static int arm_v7s_map_pages(struct io_pgtable_ops *ops, unsigned long iova,
545 phys_addr_t paddr, size_t pgsize, size_t pgcount,
546 int prot, gfp_t gfp, size_t *mapped)
547{
548 struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops);
549 int ret = -EINVAL;
550
551 if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias) ||
552 paddr >= (1ULL << data->iop.cfg.oas)))
553 return -ERANGE;
554
555 /* If no access, then nothing to do */
556 if (!(prot & (IOMMU_READ | IOMMU_WRITE)))
557 return 0;
558
559 while (pgcount--) {
560 ret = __arm_v7s_map(data, iova, paddr, size: pgsize, prot, lvl: 1, ptep: data->pgd,
561 gfp);
562 if (ret)
563 break;
564
565 iova += pgsize;
566 paddr += pgsize;
567 *mapped += pgsize;
568 }
569 /*
570 * Synchronise all PTE updates for the new mapping before there's
571 * a chance for anything to kick off a table walk for the new iova.
572 */
573 wmb();
574
575 return ret;
576}
577
578static void arm_v7s_free_pgtable(struct io_pgtable *iop)
579{
580 struct arm_v7s_io_pgtable *data = io_pgtable_to_data(iop);
581 int i;
582
583 for (i = 0; i < ARM_V7S_PTES_PER_LVL(1, &data->iop.cfg); i++) {
584 arm_v7s_iopte pte = data->pgd[i];
585
586 if (ARM_V7S_PTE_IS_TABLE(pte, 1))
587 __arm_v7s_free_table(table: iopte_deref(pte, lvl: 1, data),
588 lvl: 2, data);
589 }
590 __arm_v7s_free_table(table: data->pgd, lvl: 1, data);
591 kmem_cache_destroy(s: data->l2_tables);
592 kfree(objp: data);
593}
594
595static arm_v7s_iopte arm_v7s_split_cont(struct arm_v7s_io_pgtable *data,
596 unsigned long iova, int idx, int lvl,
597 arm_v7s_iopte *ptep)
598{
599 struct io_pgtable *iop = &data->iop;
600 arm_v7s_iopte pte;
601 size_t size = ARM_V7S_BLOCK_SIZE(lvl);
602 int i;
603
604 /* Check that we didn't lose a race to get the lock */
605 pte = *ptep;
606 if (!arm_v7s_pte_is_cont(pte, lvl))
607 return pte;
608
609 ptep -= idx & (ARM_V7S_CONT_PAGES - 1);
610 pte = arm_v7s_cont_to_pte(pte, lvl);
611 for (i = 0; i < ARM_V7S_CONT_PAGES; i++)
612 ptep[i] = pte + i * size;
613
614 __arm_v7s_pte_sync(ptep, ARM_V7S_CONT_PAGES, cfg: &iop->cfg);
615
616 size *= ARM_V7S_CONT_PAGES;
617 io_pgtable_tlb_flush_walk(iop, iova, size, granule: size);
618 return pte;
619}
620
621static size_t arm_v7s_split_blk_unmap(struct arm_v7s_io_pgtable *data,
622 struct iommu_iotlb_gather *gather,
623 unsigned long iova, size_t size,
624 arm_v7s_iopte blk_pte,
625 arm_v7s_iopte *ptep)
626{
627 struct io_pgtable_cfg *cfg = &data->iop.cfg;
628 arm_v7s_iopte pte, *tablep;
629 int i, unmap_idx, num_entries, num_ptes;
630
631 tablep = __arm_v7s_alloc_table(lvl: 2, GFP_ATOMIC, data);
632 if (!tablep)
633 return 0; /* Bytes unmapped */
634
635 num_ptes = ARM_V7S_PTES_PER_LVL(2, cfg);
636 num_entries = size >> ARM_V7S_LVL_SHIFT(2);
637 unmap_idx = ARM_V7S_LVL_IDX(iova, 2, cfg);
638
639 pte = arm_v7s_prot_to_pte(prot: arm_v7s_pte_to_prot(pte: blk_pte, lvl: 1), lvl: 2, cfg);
640 if (num_entries > 1)
641 pte = arm_v7s_pte_to_cont(pte, lvl: 2);
642
643 for (i = 0; i < num_ptes; i += num_entries, pte += size) {
644 /* Unmap! */
645 if (i == unmap_idx)
646 continue;
647
648 __arm_v7s_set_pte(ptep: &tablep[i], pte, num_entries, cfg);
649 }
650
651 pte = arm_v7s_install_table(table: tablep, ptep, curr: blk_pte, cfg);
652 if (pte != blk_pte) {
653 __arm_v7s_free_table(table: tablep, lvl: 2, data);
654
655 if (!ARM_V7S_PTE_IS_TABLE(pte, 1))
656 return 0;
657
658 tablep = iopte_deref(pte, lvl: 1, data);
659 return __arm_v7s_unmap(data, gather, iova, size, 2, tablep);
660 }
661
662 io_pgtable_tlb_add_page(iop: &data->iop, gather, iova, granule: size);
663 return size;
664}
665
666static size_t __arm_v7s_unmap(struct arm_v7s_io_pgtable *data,
667 struct iommu_iotlb_gather *gather,
668 unsigned long iova, size_t size, int lvl,
669 arm_v7s_iopte *ptep)
670{
671 arm_v7s_iopte pte[ARM_V7S_CONT_PAGES];
672 struct io_pgtable *iop = &data->iop;
673 int idx, i = 0, num_entries = size >> ARM_V7S_LVL_SHIFT(lvl);
674
675 /* Something went horribly wrong and we ran out of page table */
676 if (WARN_ON(lvl > 2))
677 return 0;
678
679 idx = ARM_V7S_LVL_IDX(iova, lvl, &iop->cfg);
680 ptep += idx;
681 do {
682 pte[i] = READ_ONCE(ptep[i]);
683 if (WARN_ON(!ARM_V7S_PTE_IS_VALID(pte[i])))
684 return 0;
685 } while (++i < num_entries);
686
687 /*
688 * If we've hit a contiguous 'large page' entry at this level, it
689 * needs splitting first, unless we're unmapping the whole lot.
690 *
691 * For splitting, we can't rewrite 16 PTEs atomically, and since we
692 * can't necessarily assume TEX remap we don't have a software bit to
693 * mark live entries being split. In practice (i.e. DMA API code), we
694 * will never be splitting large pages anyway, so just wrap this edge
695 * case in a lock for the sake of correctness and be done with it.
696 */
697 if (num_entries <= 1 && arm_v7s_pte_is_cont(pte: pte[0], lvl)) {
698 unsigned long flags;
699
700 spin_lock_irqsave(&data->split_lock, flags);
701 pte[0] = arm_v7s_split_cont(data, iova, idx, lvl, ptep);
702 spin_unlock_irqrestore(lock: &data->split_lock, flags);
703 }
704
705 /* If the size matches this level, we're in the right place */
706 if (num_entries) {
707 size_t blk_size = ARM_V7S_BLOCK_SIZE(lvl);
708
709 __arm_v7s_set_pte(ptep, pte: 0, num_entries, cfg: &iop->cfg);
710
711 for (i = 0; i < num_entries; i++) {
712 if (ARM_V7S_PTE_IS_TABLE(pte[i], lvl)) {
713 /* Also flush any partial walks */
714 io_pgtable_tlb_flush_walk(iop, iova, size: blk_size,
715 ARM_V7S_BLOCK_SIZE(lvl + 1));
716 ptep = iopte_deref(pte: pte[i], lvl, data);
717 __arm_v7s_free_table(table: ptep, lvl: lvl + 1, data);
718 } else if (!iommu_iotlb_gather_queued(gather)) {
719 io_pgtable_tlb_add_page(iop, gather, iova, granule: blk_size);
720 }
721 iova += blk_size;
722 }
723 return size;
724 } else if (lvl == 1 && !ARM_V7S_PTE_IS_TABLE(pte[0], lvl)) {
725 /*
726 * Insert a table at the next level to map the old region,
727 * minus the part we want to unmap
728 */
729 return arm_v7s_split_blk_unmap(data, gather, iova, size, blk_pte: pte[0],
730 ptep);
731 }
732
733 /* Keep on walkin' */
734 ptep = iopte_deref(pte: pte[0], lvl, data);
735 return __arm_v7s_unmap(data, gather, iova, size, lvl: lvl + 1, ptep);
736}
737
738static size_t arm_v7s_unmap_pages(struct io_pgtable_ops *ops, unsigned long iova,
739 size_t pgsize, size_t pgcount,
740 struct iommu_iotlb_gather *gather)
741{
742 struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops);
743 size_t unmapped = 0, ret;
744
745 if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias)))
746 return 0;
747
748 while (pgcount--) {
749 ret = __arm_v7s_unmap(data, gather, iova, size: pgsize, lvl: 1, ptep: data->pgd);
750 if (!ret)
751 break;
752
753 unmapped += pgsize;
754 iova += pgsize;
755 }
756
757 return unmapped;
758}
759
760static phys_addr_t arm_v7s_iova_to_phys(struct io_pgtable_ops *ops,
761 unsigned long iova)
762{
763 struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops);
764 arm_v7s_iopte *ptep = data->pgd, pte;
765 int lvl = 0;
766 u32 mask;
767
768 do {
769 ptep += ARM_V7S_LVL_IDX(iova, ++lvl, &data->iop.cfg);
770 pte = READ_ONCE(*ptep);
771 ptep = iopte_deref(pte, lvl, data);
772 } while (ARM_V7S_PTE_IS_TABLE(pte, lvl));
773
774 if (!ARM_V7S_PTE_IS_VALID(pte))
775 return 0;
776
777 mask = ARM_V7S_LVL_MASK(lvl);
778 if (arm_v7s_pte_is_cont(pte, lvl))
779 mask *= ARM_V7S_CONT_PAGES;
780 return iopte_to_paddr(pte, lvl, cfg: &data->iop.cfg) | (iova & ~mask);
781}
782
783static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg,
784 void *cookie)
785{
786 struct arm_v7s_io_pgtable *data;
787 slab_flags_t slab_flag;
788 phys_addr_t paddr;
789
790 if (cfg->ias > (arm_v7s_is_mtk_enabled(cfg) ? 34 : ARM_V7S_ADDR_BITS))
791 return NULL;
792
793 if (cfg->oas > (arm_v7s_is_mtk_enabled(cfg) ? 35 : ARM_V7S_ADDR_BITS))
794 return NULL;
795
796 if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS |
797 IO_PGTABLE_QUIRK_NO_PERMS |
798 IO_PGTABLE_QUIRK_ARM_MTK_EXT |
799 IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT))
800 return NULL;
801
802 /* If ARM_MTK_4GB is enabled, the NO_PERMS is also expected. */
803 if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_EXT &&
804 !(cfg->quirks & IO_PGTABLE_QUIRK_NO_PERMS))
805 return NULL;
806
807 if ((cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT) &&
808 !arm_v7s_is_mtk_enabled(cfg))
809 return NULL;
810
811 data = kmalloc(size: sizeof(*data), GFP_KERNEL);
812 if (!data)
813 return NULL;
814
815 spin_lock_init(&data->split_lock);
816
817 /*
818 * ARM_MTK_TTBR_EXT extend the translation table base support larger
819 * memory address.
820 */
821 slab_flag = cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_TTBR_EXT ?
822 0 : ARM_V7S_TABLE_SLAB_FLAGS;
823
824 data->l2_tables = kmem_cache_create(name: "io-pgtable_armv7s_l2",
825 ARM_V7S_TABLE_SIZE(2, cfg),
826 ARM_V7S_TABLE_SIZE(2, cfg),
827 flags: slab_flag, NULL);
828 if (!data->l2_tables)
829 goto out_free_data;
830
831 data->iop.ops = (struct io_pgtable_ops) {
832 .map_pages = arm_v7s_map_pages,
833 .unmap_pages = arm_v7s_unmap_pages,
834 .iova_to_phys = arm_v7s_iova_to_phys,
835 };
836
837 /* We have to do this early for __arm_v7s_alloc_table to work... */
838 data->iop.cfg = *cfg;
839
840 /*
841 * Unless the IOMMU driver indicates supersection support by
842 * having SZ_16M set in the initial bitmap, they won't be used.
843 */
844 cfg->pgsize_bitmap &= SZ_4K | SZ_64K | SZ_1M | SZ_16M;
845
846 /* TCR: T0SZ=0, EAE=0 (if applicable) */
847 cfg->arm_v7s_cfg.tcr = 0;
848
849 /*
850 * TEX remap: the indices used map to the closest equivalent types
851 * under the non-TEX-remap interpretation of those attribute bits,
852 * excepting various implementation-defined aspects of shareability.
853 */
854 cfg->arm_v7s_cfg.prrr = ARM_V7S_PRRR_TR(1, ARM_V7S_PRRR_TYPE_DEVICE) |
855 ARM_V7S_PRRR_TR(4, ARM_V7S_PRRR_TYPE_NORMAL) |
856 ARM_V7S_PRRR_TR(7, ARM_V7S_PRRR_TYPE_NORMAL) |
857 ARM_V7S_PRRR_DS0 | ARM_V7S_PRRR_DS1 |
858 ARM_V7S_PRRR_NS1 | ARM_V7S_PRRR_NOS(7);
859 cfg->arm_v7s_cfg.nmrr = ARM_V7S_NMRR_IR(7, ARM_V7S_RGN_WBWA) |
860 ARM_V7S_NMRR_OR(7, ARM_V7S_RGN_WBWA);
861
862 /* Looking good; allocate a pgd */
863 data->pgd = __arm_v7s_alloc_table(lvl: 1, GFP_KERNEL, data);
864 if (!data->pgd)
865 goto out_free_data;
866
867 /* Ensure the empty pgd is visible before any actual TTBR write */
868 wmb();
869
870 /* TTBR */
871 paddr = virt_to_phys(address: data->pgd);
872 if (arm_v7s_is_mtk_enabled(cfg))
873 cfg->arm_v7s_cfg.ttbr = paddr | upper_32_bits(paddr);
874 else
875 cfg->arm_v7s_cfg.ttbr = paddr | ARM_V7S_TTBR_S |
876 (cfg->coherent_walk ? (ARM_V7S_TTBR_NOS |
877 ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_WBWA) |
878 ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_WBWA)) :
879 (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_NC) |
880 ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_NC)));
881 return &data->iop;
882
883out_free_data:
884 kmem_cache_destroy(s: data->l2_tables);
885 kfree(objp: data);
886 return NULL;
887}
888
889struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns = {
890 .alloc = arm_v7s_alloc_pgtable,
891 .free = arm_v7s_free_pgtable,
892};
893
894#ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S_SELFTEST
895
896static struct io_pgtable_cfg *cfg_cookie __initdata;
897
898static void __init dummy_tlb_flush_all(void *cookie)
899{
900 WARN_ON(cookie != cfg_cookie);
901}
902
903static void __init dummy_tlb_flush(unsigned long iova, size_t size,
904 size_t granule, void *cookie)
905{
906 WARN_ON(cookie != cfg_cookie);
907 WARN_ON(!(size & cfg_cookie->pgsize_bitmap));
908}
909
910static void __init dummy_tlb_add_page(struct iommu_iotlb_gather *gather,
911 unsigned long iova, size_t granule,
912 void *cookie)
913{
914 dummy_tlb_flush(iova, size: granule, granule, cookie);
915}
916
917static const struct iommu_flush_ops dummy_tlb_ops __initconst = {
918 .tlb_flush_all = dummy_tlb_flush_all,
919 .tlb_flush_walk = dummy_tlb_flush,
920 .tlb_add_page = dummy_tlb_add_page,
921};
922
923#define __FAIL(ops) ({ \
924 WARN(1, "selftest: test failed\n"); \
925 selftest_running = false; \
926 -EFAULT; \
927})
928
929static int __init arm_v7s_do_selftests(void)
930{
931 struct io_pgtable_ops *ops;
932 struct io_pgtable_cfg cfg = {
933 .tlb = &dummy_tlb_ops,
934 .oas = 32,
935 .ias = 32,
936 .coherent_walk = true,
937 .quirks = IO_PGTABLE_QUIRK_ARM_NS,
938 .pgsize_bitmap = SZ_4K | SZ_64K | SZ_1M | SZ_16M,
939 };
940 unsigned int iova, size, iova_start;
941 unsigned int i, loopnr = 0;
942 size_t mapped;
943
944 selftest_running = true;
945
946 cfg_cookie = &cfg;
947
948 ops = alloc_io_pgtable_ops(fmt: ARM_V7S, cfg: &cfg, cookie: &cfg);
949 if (!ops) {
950 pr_err("selftest: failed to allocate io pgtable ops\n");
951 return -EINVAL;
952 }
953
954 /*
955 * Initial sanity checks.
956 * Empty page tables shouldn't provide any translations.
957 */
958 if (ops->iova_to_phys(ops, 42))
959 return __FAIL(ops);
960
961 if (ops->iova_to_phys(ops, SZ_1G + 42))
962 return __FAIL(ops);
963
964 if (ops->iova_to_phys(ops, SZ_2G + 42))
965 return __FAIL(ops);
966
967 /*
968 * Distinct mappings of different granule sizes.
969 */
970 iova = 0;
971 for_each_set_bit(i, &cfg.pgsize_bitmap, BITS_PER_LONG) {
972 size = 1UL << i;
973 if (ops->map_pages(ops, iova, iova, size, 1,
974 IOMMU_READ | IOMMU_WRITE |
975 IOMMU_NOEXEC | IOMMU_CACHE,
976 GFP_KERNEL, &mapped))
977 return __FAIL(ops);
978
979 /* Overlapping mappings */
980 if (!ops->map_pages(ops, iova, iova + size, size, 1,
981 IOMMU_READ | IOMMU_NOEXEC, GFP_KERNEL,
982 &mapped))
983 return __FAIL(ops);
984
985 if (ops->iova_to_phys(ops, iova + 42) != (iova + 42))
986 return __FAIL(ops);
987
988 iova += SZ_16M;
989 loopnr++;
990 }
991
992 /* Partial unmap */
993 i = 1;
994 size = 1UL << __ffs(cfg.pgsize_bitmap);
995 while (i < loopnr) {
996 iova_start = i * SZ_16M;
997 if (ops->unmap_pages(ops, iova_start + size, size, 1, NULL) != size)
998 return __FAIL(ops);
999
1000 /* Remap of partial unmap */
1001 if (ops->map_pages(ops, iova_start + size, size, size, 1,
1002 IOMMU_READ, GFP_KERNEL, &mapped))
1003 return __FAIL(ops);
1004
1005 if (ops->iova_to_phys(ops, iova_start + size + 42)
1006 != (size + 42))
1007 return __FAIL(ops);
1008 i++;
1009 }
1010
1011 /* Full unmap */
1012 iova = 0;
1013 for_each_set_bit(i, &cfg.pgsize_bitmap, BITS_PER_LONG) {
1014 size = 1UL << i;
1015
1016 if (ops->unmap_pages(ops, iova, size, 1, NULL) != size)
1017 return __FAIL(ops);
1018
1019 if (ops->iova_to_phys(ops, iova + 42))
1020 return __FAIL(ops);
1021
1022 /* Remap full block */
1023 if (ops->map_pages(ops, iova, iova, size, 1, IOMMU_WRITE,
1024 GFP_KERNEL, &mapped))
1025 return __FAIL(ops);
1026
1027 if (ops->iova_to_phys(ops, iova + 42) != (iova + 42))
1028 return __FAIL(ops);
1029
1030 iova += SZ_16M;
1031 }
1032
1033 free_io_pgtable_ops(ops);
1034
1035 selftest_running = false;
1036
1037 pr_info("self test ok\n");
1038 return 0;
1039}
1040subsys_initcall(arm_v7s_do_selftests);
1041#endif
1042

source code of linux/drivers/iommu/io-pgtable-arm-v7s.c