1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * IOMMU API for Renesas VMSA-compatible IPMMU
4 * Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
5 *
6 * Copyright (C) 2014-2020 Renesas Electronics Corporation
7 */
8
9 #include <linux/bitmap.h>
10 #include <linux/delay.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/err.h>
13 #include <linux/export.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/iopoll.h>
18 #include <linux/io-pgtable.h>
19 #include <linux/iommu.h>
20 #include <linux/of.h>
21 #include <linux/of_platform.h>
22 #include <linux/pci.h>
23 #include <linux/platform_device.h>
24 #include <linux/sizes.h>
25 #include <linux/slab.h>
26 #include <linux/sys_soc.h>
27
28 #if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
29 #include <asm/dma-iommu.h>
30 #else
31 #define arm_iommu_create_mapping(...) NULL
32 #define arm_iommu_attach_device(...) -ENODEV
33 #define arm_iommu_release_mapping(...) do {} while (0)
34 #endif
35
36 #define IPMMU_CTX_MAX 16U
37 #define IPMMU_CTX_INVALID -1
38
39 #define IPMMU_UTLB_MAX 64U
40
41 struct ipmmu_features {
42 bool use_ns_alias_offset;
43 bool has_cache_leaf_nodes;
44 unsigned int number_of_contexts;
45 unsigned int num_utlbs;
46 bool setup_imbuscr;
47 bool twobit_imttbcr_sl0;
48 bool reserved_context;
49 bool cache_snoop;
50 unsigned int ctx_offset_base;
51 unsigned int ctx_offset_stride;
52 unsigned int utlb_offset_base;
53 };
54
55 struct ipmmu_vmsa_device {
56 struct device *dev;
57 void __iomem *base;
58 struct iommu_device iommu;
59 struct ipmmu_vmsa_device *root;
60 const struct ipmmu_features *features;
61 unsigned int num_ctx;
62 spinlock_t lock; /* Protects ctx and domains[] */
63 DECLARE_BITMAP(ctx, IPMMU_CTX_MAX);
64 struct ipmmu_vmsa_domain *domains[IPMMU_CTX_MAX];
65 s8 utlb_ctx[IPMMU_UTLB_MAX];
66
67 struct dma_iommu_mapping *mapping;
68 };
69
70 struct ipmmu_vmsa_domain {
71 struct ipmmu_vmsa_device *mmu;
72 struct iommu_domain io_domain;
73
74 struct io_pgtable_cfg cfg;
75 struct io_pgtable_ops *iop;
76
77 unsigned int context_id;
78 struct mutex mutex; /* Protects mappings */
79 };
80
to_vmsa_domain(struct iommu_domain * dom)81 static struct ipmmu_vmsa_domain *to_vmsa_domain(struct iommu_domain *dom)
82 {
83 return container_of(dom, struct ipmmu_vmsa_domain, io_domain);
84 }
85
to_ipmmu(struct device * dev)86 static struct ipmmu_vmsa_device *to_ipmmu(struct device *dev)
87 {
88 return dev_iommu_priv_get(dev);
89 }
90
91 #define TLB_LOOP_TIMEOUT 100 /* 100us */
92
93 /* -----------------------------------------------------------------------------
94 * Registers Definition
95 */
96
97 #define IM_NS_ALIAS_OFFSET 0x800
98
99 /* MMU "context" registers */
100 #define IMCTR 0x0000 /* R-Car Gen2/3 */
101 #define IMCTR_INTEN (1 << 2) /* R-Car Gen2/3 */
102 #define IMCTR_FLUSH (1 << 1) /* R-Car Gen2/3 */
103 #define IMCTR_MMUEN (1 << 0) /* R-Car Gen2/3 */
104
105 #define IMTTBCR 0x0008 /* R-Car Gen2/3 */
106 #define IMTTBCR_EAE (1 << 31) /* R-Car Gen2/3 */
107 #define IMTTBCR_SH0_INNER_SHAREABLE (3 << 12) /* R-Car Gen2 only */
108 #define IMTTBCR_ORGN0_WB_WA (1 << 10) /* R-Car Gen2 only */
109 #define IMTTBCR_IRGN0_WB_WA (1 << 8) /* R-Car Gen2 only */
110 #define IMTTBCR_SL0_TWOBIT_LVL_1 (2 << 6) /* R-Car Gen3 only */
111 #define IMTTBCR_SL0_LVL_1 (1 << 4) /* R-Car Gen2 only */
112
113 #define IMBUSCR 0x000c /* R-Car Gen2 only */
114 #define IMBUSCR_DVM (1 << 2) /* R-Car Gen2 only */
115 #define IMBUSCR_BUSSEL_MASK (3 << 0) /* R-Car Gen2 only */
116
117 #define IMTTLBR0 0x0010 /* R-Car Gen2/3 */
118 #define IMTTUBR0 0x0014 /* R-Car Gen2/3 */
119
120 #define IMSTR 0x0020 /* R-Car Gen2/3 */
121 #define IMSTR_MHIT (1 << 4) /* R-Car Gen2/3 */
122 #define IMSTR_ABORT (1 << 2) /* R-Car Gen2/3 */
123 #define IMSTR_PF (1 << 1) /* R-Car Gen2/3 */
124 #define IMSTR_TF (1 << 0) /* R-Car Gen2/3 */
125
126 #define IMMAIR0 0x0028 /* R-Car Gen2/3 */
127
128 #define IMELAR 0x0030 /* R-Car Gen2/3, IMEAR on R-Car Gen2 */
129 #define IMEUAR 0x0034 /* R-Car Gen3 only */
130
131 /* uTLB registers */
132 #define IMUCTR(n) ((n) < 32 ? IMUCTR0(n) : IMUCTR32(n))
133 #define IMUCTR0(n) (0x0300 + ((n) * 16)) /* R-Car Gen2/3 */
134 #define IMUCTR32(n) (0x0600 + (((n) - 32) * 16)) /* R-Car Gen3 only */
135 #define IMUCTR_TTSEL_MMU(n) ((n) << 4) /* R-Car Gen2/3 */
136 #define IMUCTR_FLUSH (1 << 1) /* R-Car Gen2/3 */
137 #define IMUCTR_MMUEN (1 << 0) /* R-Car Gen2/3 */
138
139 #define IMUASID(n) ((n) < 32 ? IMUASID0(n) : IMUASID32(n))
140 #define IMUASID0(n) (0x0308 + ((n) * 16)) /* R-Car Gen2/3 */
141 #define IMUASID32(n) (0x0608 + (((n) - 32) * 16)) /* R-Car Gen3 only */
142
143 /* -----------------------------------------------------------------------------
144 * Root device handling
145 */
146
147 static struct platform_driver ipmmu_driver;
148
ipmmu_is_root(struct ipmmu_vmsa_device * mmu)149 static bool ipmmu_is_root(struct ipmmu_vmsa_device *mmu)
150 {
151 return mmu->root == mmu;
152 }
153
__ipmmu_check_device(struct device * dev,void * data)154 static int __ipmmu_check_device(struct device *dev, void *data)
155 {
156 struct ipmmu_vmsa_device *mmu = dev_get_drvdata(dev);
157 struct ipmmu_vmsa_device **rootp = data;
158
159 if (ipmmu_is_root(mmu))
160 *rootp = mmu;
161
162 return 0;
163 }
164
ipmmu_find_root(void)165 static struct ipmmu_vmsa_device *ipmmu_find_root(void)
166 {
167 struct ipmmu_vmsa_device *root = NULL;
168
169 return driver_for_each_device(&ipmmu_driver.driver, NULL, &root,
170 __ipmmu_check_device) == 0 ? root : NULL;
171 }
172
173 /* -----------------------------------------------------------------------------
174 * Read/Write Access
175 */
176
ipmmu_read(struct ipmmu_vmsa_device * mmu,unsigned int offset)177 static u32 ipmmu_read(struct ipmmu_vmsa_device *mmu, unsigned int offset)
178 {
179 return ioread32(mmu->base + offset);
180 }
181
ipmmu_write(struct ipmmu_vmsa_device * mmu,unsigned int offset,u32 data)182 static void ipmmu_write(struct ipmmu_vmsa_device *mmu, unsigned int offset,
183 u32 data)
184 {
185 iowrite32(data, mmu->base + offset);
186 }
187
ipmmu_ctx_reg(struct ipmmu_vmsa_device * mmu,unsigned int context_id,unsigned int reg)188 static unsigned int ipmmu_ctx_reg(struct ipmmu_vmsa_device *mmu,
189 unsigned int context_id, unsigned int reg)
190 {
191 unsigned int base = mmu->features->ctx_offset_base;
192
193 if (context_id > 7)
194 base += 0x800 - 8 * 0x40;
195
196 return base + context_id * mmu->features->ctx_offset_stride + reg;
197 }
198
ipmmu_ctx_read(struct ipmmu_vmsa_device * mmu,unsigned int context_id,unsigned int reg)199 static u32 ipmmu_ctx_read(struct ipmmu_vmsa_device *mmu,
200 unsigned int context_id, unsigned int reg)
201 {
202 return ipmmu_read(mmu, ipmmu_ctx_reg(mmu, context_id, reg));
203 }
204
ipmmu_ctx_write(struct ipmmu_vmsa_device * mmu,unsigned int context_id,unsigned int reg,u32 data)205 static void ipmmu_ctx_write(struct ipmmu_vmsa_device *mmu,
206 unsigned int context_id, unsigned int reg, u32 data)
207 {
208 ipmmu_write(mmu, ipmmu_ctx_reg(mmu, context_id, reg), data);
209 }
210
ipmmu_ctx_read_root(struct ipmmu_vmsa_domain * domain,unsigned int reg)211 static u32 ipmmu_ctx_read_root(struct ipmmu_vmsa_domain *domain,
212 unsigned int reg)
213 {
214 return ipmmu_ctx_read(domain->mmu->root, domain->context_id, reg);
215 }
216
ipmmu_ctx_write_root(struct ipmmu_vmsa_domain * domain,unsigned int reg,u32 data)217 static void ipmmu_ctx_write_root(struct ipmmu_vmsa_domain *domain,
218 unsigned int reg, u32 data)
219 {
220 ipmmu_ctx_write(domain->mmu->root, domain->context_id, reg, data);
221 }
222
ipmmu_ctx_write_all(struct ipmmu_vmsa_domain * domain,unsigned int reg,u32 data)223 static void ipmmu_ctx_write_all(struct ipmmu_vmsa_domain *domain,
224 unsigned int reg, u32 data)
225 {
226 if (domain->mmu != domain->mmu->root)
227 ipmmu_ctx_write(domain->mmu, domain->context_id, reg, data);
228
229 ipmmu_ctx_write(domain->mmu->root, domain->context_id, reg, data);
230 }
231
ipmmu_utlb_reg(struct ipmmu_vmsa_device * mmu,unsigned int reg)232 static u32 ipmmu_utlb_reg(struct ipmmu_vmsa_device *mmu, unsigned int reg)
233 {
234 return mmu->features->utlb_offset_base + reg;
235 }
236
ipmmu_imuasid_write(struct ipmmu_vmsa_device * mmu,unsigned int utlb,u32 data)237 static void ipmmu_imuasid_write(struct ipmmu_vmsa_device *mmu,
238 unsigned int utlb, u32 data)
239 {
240 ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUASID(utlb)), data);
241 }
242
ipmmu_imuctr_write(struct ipmmu_vmsa_device * mmu,unsigned int utlb,u32 data)243 static void ipmmu_imuctr_write(struct ipmmu_vmsa_device *mmu,
244 unsigned int utlb, u32 data)
245 {
246 ipmmu_write(mmu, ipmmu_utlb_reg(mmu, IMUCTR(utlb)), data);
247 }
248
249 /* -----------------------------------------------------------------------------
250 * TLB and microTLB Management
251 */
252
253 /* Wait for any pending TLB invalidations to complete */
ipmmu_tlb_sync(struct ipmmu_vmsa_domain * domain)254 static void ipmmu_tlb_sync(struct ipmmu_vmsa_domain *domain)
255 {
256 u32 val;
257
258 if (read_poll_timeout_atomic(ipmmu_ctx_read_root, val,
259 !(val & IMCTR_FLUSH), 1, TLB_LOOP_TIMEOUT,
260 false, domain, IMCTR))
261 dev_err_ratelimited(domain->mmu->dev,
262 "TLB sync timed out -- MMU may be deadlocked\n");
263 }
264
ipmmu_tlb_invalidate(struct ipmmu_vmsa_domain * domain)265 static void ipmmu_tlb_invalidate(struct ipmmu_vmsa_domain *domain)
266 {
267 u32 reg;
268
269 reg = ipmmu_ctx_read_root(domain, IMCTR);
270 reg |= IMCTR_FLUSH;
271 ipmmu_ctx_write_all(domain, IMCTR, reg);
272
273 ipmmu_tlb_sync(domain);
274 }
275
276 /*
277 * Enable MMU translation for the microTLB.
278 */
ipmmu_utlb_enable(struct ipmmu_vmsa_domain * domain,unsigned int utlb)279 static void ipmmu_utlb_enable(struct ipmmu_vmsa_domain *domain,
280 unsigned int utlb)
281 {
282 struct ipmmu_vmsa_device *mmu = domain->mmu;
283
284 /*
285 * TODO: Reference-count the microTLB as several bus masters can be
286 * connected to the same microTLB.
287 */
288
289 /* TODO: What should we set the ASID to ? */
290 ipmmu_imuasid_write(mmu, utlb, 0);
291 /* TODO: Do we need to flush the microTLB ? */
292 ipmmu_imuctr_write(mmu, utlb, IMUCTR_TTSEL_MMU(domain->context_id) |
293 IMUCTR_FLUSH | IMUCTR_MMUEN);
294 mmu->utlb_ctx[utlb] = domain->context_id;
295 }
296
297 /*
298 * Disable MMU translation for the microTLB.
299 */
ipmmu_utlb_disable(struct ipmmu_vmsa_domain * domain,unsigned int utlb)300 static void ipmmu_utlb_disable(struct ipmmu_vmsa_domain *domain,
301 unsigned int utlb)
302 {
303 struct ipmmu_vmsa_device *mmu = domain->mmu;
304
305 ipmmu_imuctr_write(mmu, utlb, 0);
306 mmu->utlb_ctx[utlb] = IPMMU_CTX_INVALID;
307 }
308
ipmmu_tlb_flush_all(void * cookie)309 static void ipmmu_tlb_flush_all(void *cookie)
310 {
311 struct ipmmu_vmsa_domain *domain = cookie;
312
313 ipmmu_tlb_invalidate(domain);
314 }
315
ipmmu_tlb_flush(unsigned long iova,size_t size,size_t granule,void * cookie)316 static void ipmmu_tlb_flush(unsigned long iova, size_t size,
317 size_t granule, void *cookie)
318 {
319 ipmmu_tlb_flush_all(cookie);
320 }
321
322 static const struct iommu_flush_ops ipmmu_flush_ops = {
323 .tlb_flush_all = ipmmu_tlb_flush_all,
324 .tlb_flush_walk = ipmmu_tlb_flush,
325 };
326
327 /* -----------------------------------------------------------------------------
328 * Domain/Context Management
329 */
330
ipmmu_domain_allocate_context(struct ipmmu_vmsa_device * mmu,struct ipmmu_vmsa_domain * domain)331 static int ipmmu_domain_allocate_context(struct ipmmu_vmsa_device *mmu,
332 struct ipmmu_vmsa_domain *domain)
333 {
334 unsigned long flags;
335 int ret;
336
337 spin_lock_irqsave(&mmu->lock, flags);
338
339 ret = find_first_zero_bit(mmu->ctx, mmu->num_ctx);
340 if (ret != mmu->num_ctx) {
341 mmu->domains[ret] = domain;
342 set_bit(ret, mmu->ctx);
343 } else
344 ret = -EBUSY;
345
346 spin_unlock_irqrestore(&mmu->lock, flags);
347
348 return ret;
349 }
350
ipmmu_domain_free_context(struct ipmmu_vmsa_device * mmu,unsigned int context_id)351 static void ipmmu_domain_free_context(struct ipmmu_vmsa_device *mmu,
352 unsigned int context_id)
353 {
354 unsigned long flags;
355
356 spin_lock_irqsave(&mmu->lock, flags);
357
358 clear_bit(context_id, mmu->ctx);
359 mmu->domains[context_id] = NULL;
360
361 spin_unlock_irqrestore(&mmu->lock, flags);
362 }
363
ipmmu_domain_setup_context(struct ipmmu_vmsa_domain * domain)364 static void ipmmu_domain_setup_context(struct ipmmu_vmsa_domain *domain)
365 {
366 u64 ttbr;
367 u32 tmp;
368
369 /* TTBR0 */
370 ttbr = domain->cfg.arm_lpae_s1_cfg.ttbr;
371 ipmmu_ctx_write_root(domain, IMTTLBR0, ttbr);
372 ipmmu_ctx_write_root(domain, IMTTUBR0, ttbr >> 32);
373
374 /*
375 * TTBCR
376 * We use long descriptors and allocate the whole 32-bit VA space to
377 * TTBR0.
378 */
379 if (domain->mmu->features->twobit_imttbcr_sl0)
380 tmp = IMTTBCR_SL0_TWOBIT_LVL_1;
381 else
382 tmp = IMTTBCR_SL0_LVL_1;
383
384 if (domain->mmu->features->cache_snoop)
385 tmp |= IMTTBCR_SH0_INNER_SHAREABLE | IMTTBCR_ORGN0_WB_WA |
386 IMTTBCR_IRGN0_WB_WA;
387
388 ipmmu_ctx_write_root(domain, IMTTBCR, IMTTBCR_EAE | tmp);
389
390 /* MAIR0 */
391 ipmmu_ctx_write_root(domain, IMMAIR0,
392 domain->cfg.arm_lpae_s1_cfg.mair);
393
394 /* IMBUSCR */
395 if (domain->mmu->features->setup_imbuscr)
396 ipmmu_ctx_write_root(domain, IMBUSCR,
397 ipmmu_ctx_read_root(domain, IMBUSCR) &
398 ~(IMBUSCR_DVM | IMBUSCR_BUSSEL_MASK));
399
400 /*
401 * IMSTR
402 * Clear all interrupt flags.
403 */
404 ipmmu_ctx_write_root(domain, IMSTR, ipmmu_ctx_read_root(domain, IMSTR));
405
406 /*
407 * IMCTR
408 * Enable the MMU and interrupt generation. The long-descriptor
409 * translation table format doesn't use TEX remapping. Don't enable AF
410 * software management as we have no use for it. Flush the TLB as
411 * required when modifying the context registers.
412 */
413 ipmmu_ctx_write_all(domain, IMCTR,
414 IMCTR_INTEN | IMCTR_FLUSH | IMCTR_MMUEN);
415 }
416
ipmmu_domain_init_context(struct ipmmu_vmsa_domain * domain)417 static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
418 {
419 int ret;
420
421 /*
422 * Allocate the page table operations.
423 *
424 * VMSA states in section B3.6.3 "Control of Secure or Non-secure memory
425 * access, Long-descriptor format" that the NStable bit being set in a
426 * table descriptor will result in the NStable and NS bits of all child
427 * entries being ignored and considered as being set. The IPMMU seems
428 * not to comply with this, as it generates a secure access page fault
429 * if any of the NStable and NS bits isn't set when running in
430 * non-secure mode.
431 */
432 domain->cfg.quirks = IO_PGTABLE_QUIRK_ARM_NS;
433 domain->cfg.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K;
434 domain->cfg.ias = 32;
435 domain->cfg.oas = 40;
436 domain->cfg.tlb = &ipmmu_flush_ops;
437 domain->io_domain.geometry.aperture_end = DMA_BIT_MASK(32);
438 domain->io_domain.geometry.force_aperture = true;
439 /*
440 * TODO: Add support for coherent walk through CCI with DVM and remove
441 * cache handling. For now, delegate it to the io-pgtable code.
442 */
443 domain->cfg.coherent_walk = false;
444 domain->cfg.iommu_dev = domain->mmu->root->dev;
445
446 /*
447 * Find an unused context.
448 */
449 ret = ipmmu_domain_allocate_context(domain->mmu->root, domain);
450 if (ret < 0)
451 return ret;
452
453 domain->context_id = ret;
454
455 domain->iop = alloc_io_pgtable_ops(ARM_32_LPAE_S1, &domain->cfg,
456 domain);
457 if (!domain->iop) {
458 ipmmu_domain_free_context(domain->mmu->root,
459 domain->context_id);
460 return -EINVAL;
461 }
462
463 ipmmu_domain_setup_context(domain);
464 return 0;
465 }
466
ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain * domain)467 static void ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain *domain)
468 {
469 if (!domain->mmu)
470 return;
471
472 /*
473 * Disable the context. Flush the TLB as required when modifying the
474 * context registers.
475 *
476 * TODO: Is TLB flush really needed ?
477 */
478 ipmmu_ctx_write_all(domain, IMCTR, IMCTR_FLUSH);
479 ipmmu_tlb_sync(domain);
480 ipmmu_domain_free_context(domain->mmu->root, domain->context_id);
481 }
482
483 /* -----------------------------------------------------------------------------
484 * Fault Handling
485 */
486
ipmmu_domain_irq(struct ipmmu_vmsa_domain * domain)487 static irqreturn_t ipmmu_domain_irq(struct ipmmu_vmsa_domain *domain)
488 {
489 const u32 err_mask = IMSTR_MHIT | IMSTR_ABORT | IMSTR_PF | IMSTR_TF;
490 struct ipmmu_vmsa_device *mmu = domain->mmu;
491 unsigned long iova;
492 u32 status;
493
494 status = ipmmu_ctx_read_root(domain, IMSTR);
495 if (!(status & err_mask))
496 return IRQ_NONE;
497
498 iova = ipmmu_ctx_read_root(domain, IMELAR);
499 if (IS_ENABLED(CONFIG_64BIT))
500 iova |= (u64)ipmmu_ctx_read_root(domain, IMEUAR) << 32;
501
502 /*
503 * Clear the error status flags. Unlike traditional interrupt flag
504 * registers that must be cleared by writing 1, this status register
505 * seems to require 0. The error address register must be read before,
506 * otherwise its value will be 0.
507 */
508 ipmmu_ctx_write_root(domain, IMSTR, 0);
509
510 /* Log fatal errors. */
511 if (status & IMSTR_MHIT)
512 dev_err_ratelimited(mmu->dev, "Multiple TLB hits @0x%lx\n",
513 iova);
514 if (status & IMSTR_ABORT)
515 dev_err_ratelimited(mmu->dev, "Page Table Walk Abort @0x%lx\n",
516 iova);
517
518 if (!(status & (IMSTR_PF | IMSTR_TF)))
519 return IRQ_NONE;
520
521 /*
522 * Try to handle page faults and translation faults.
523 *
524 * TODO: We need to look up the faulty device based on the I/O VA. Use
525 * the IOMMU device for now.
526 */
527 if (!report_iommu_fault(&domain->io_domain, mmu->dev, iova, 0))
528 return IRQ_HANDLED;
529
530 dev_err_ratelimited(mmu->dev,
531 "Unhandled fault: status 0x%08x iova 0x%lx\n",
532 status, iova);
533
534 return IRQ_HANDLED;
535 }
536
ipmmu_irq(int irq,void * dev)537 static irqreturn_t ipmmu_irq(int irq, void *dev)
538 {
539 struct ipmmu_vmsa_device *mmu = dev;
540 irqreturn_t status = IRQ_NONE;
541 unsigned int i;
542 unsigned long flags;
543
544 spin_lock_irqsave(&mmu->lock, flags);
545
546 /*
547 * Check interrupts for all active contexts.
548 */
549 for (i = 0; i < mmu->num_ctx; i++) {
550 if (!mmu->domains[i])
551 continue;
552 if (ipmmu_domain_irq(mmu->domains[i]) == IRQ_HANDLED)
553 status = IRQ_HANDLED;
554 }
555
556 spin_unlock_irqrestore(&mmu->lock, flags);
557
558 return status;
559 }
560
561 /* -----------------------------------------------------------------------------
562 * IOMMU Operations
563 */
564
ipmmu_domain_alloc_paging(struct device * dev)565 static struct iommu_domain *ipmmu_domain_alloc_paging(struct device *dev)
566 {
567 struct ipmmu_vmsa_domain *domain;
568
569 domain = kzalloc(sizeof(*domain), GFP_KERNEL);
570 if (!domain)
571 return NULL;
572
573 mutex_init(&domain->mutex);
574
575 return &domain->io_domain;
576 }
577
ipmmu_domain_free(struct iommu_domain * io_domain)578 static void ipmmu_domain_free(struct iommu_domain *io_domain)
579 {
580 struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
581
582 /*
583 * Free the domain resources. We assume that all devices have already
584 * been detached.
585 */
586 ipmmu_domain_destroy_context(domain);
587 free_io_pgtable_ops(domain->iop);
588 kfree(domain);
589 }
590
ipmmu_attach_device(struct iommu_domain * io_domain,struct device * dev)591 static int ipmmu_attach_device(struct iommu_domain *io_domain,
592 struct device *dev)
593 {
594 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
595 struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
596 struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
597 unsigned int i;
598 int ret = 0;
599
600 if (!mmu) {
601 dev_err(dev, "Cannot attach to IPMMU\n");
602 return -ENXIO;
603 }
604
605 mutex_lock(&domain->mutex);
606
607 if (!domain->mmu) {
608 /* The domain hasn't been used yet, initialize it. */
609 domain->mmu = mmu;
610 ret = ipmmu_domain_init_context(domain);
611 if (ret < 0) {
612 dev_err(dev, "Unable to initialize IPMMU context\n");
613 domain->mmu = NULL;
614 } else {
615 dev_info(dev, "Using IPMMU context %u\n",
616 domain->context_id);
617 }
618 } else if (domain->mmu != mmu) {
619 /*
620 * Something is wrong, we can't attach two devices using
621 * different IOMMUs to the same domain.
622 */
623 ret = -EINVAL;
624 } else
625 dev_info(dev, "Reusing IPMMU context %u\n", domain->context_id);
626
627 mutex_unlock(&domain->mutex);
628
629 if (ret < 0)
630 return ret;
631
632 for (i = 0; i < fwspec->num_ids; ++i)
633 ipmmu_utlb_enable(domain, fwspec->ids[i]);
634
635 return 0;
636 }
637
ipmmu_iommu_identity_attach(struct iommu_domain * identity_domain,struct device * dev)638 static int ipmmu_iommu_identity_attach(struct iommu_domain *identity_domain,
639 struct device *dev)
640 {
641 struct iommu_domain *io_domain = iommu_get_domain_for_dev(dev);
642 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
643 struct ipmmu_vmsa_domain *domain;
644 unsigned int i;
645
646 if (io_domain == identity_domain || !io_domain)
647 return 0;
648
649 domain = to_vmsa_domain(io_domain);
650 for (i = 0; i < fwspec->num_ids; ++i)
651 ipmmu_utlb_disable(domain, fwspec->ids[i]);
652
653 /*
654 * TODO: Optimize by disabling the context when no device is attached.
655 */
656 return 0;
657 }
658
659 static struct iommu_domain_ops ipmmu_iommu_identity_ops = {
660 .attach_dev = ipmmu_iommu_identity_attach,
661 };
662
663 static struct iommu_domain ipmmu_iommu_identity_domain = {
664 .type = IOMMU_DOMAIN_IDENTITY,
665 .ops = &ipmmu_iommu_identity_ops,
666 };
667
ipmmu_map(struct iommu_domain * io_domain,unsigned long iova,phys_addr_t paddr,size_t pgsize,size_t pgcount,int prot,gfp_t gfp,size_t * mapped)668 static int ipmmu_map(struct iommu_domain *io_domain, unsigned long iova,
669 phys_addr_t paddr, size_t pgsize, size_t pgcount,
670 int prot, gfp_t gfp, size_t *mapped)
671 {
672 struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
673
674 return domain->iop->map_pages(domain->iop, iova, paddr, pgsize, pgcount,
675 prot, gfp, mapped);
676 }
677
ipmmu_unmap(struct iommu_domain * io_domain,unsigned long iova,size_t pgsize,size_t pgcount,struct iommu_iotlb_gather * gather)678 static size_t ipmmu_unmap(struct iommu_domain *io_domain, unsigned long iova,
679 size_t pgsize, size_t pgcount,
680 struct iommu_iotlb_gather *gather)
681 {
682 struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
683
684 return domain->iop->unmap_pages(domain->iop, iova, pgsize, pgcount, gather);
685 }
686
ipmmu_flush_iotlb_all(struct iommu_domain * io_domain)687 static void ipmmu_flush_iotlb_all(struct iommu_domain *io_domain)
688 {
689 struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
690
691 if (domain->mmu)
692 ipmmu_tlb_flush_all(domain);
693 }
694
ipmmu_iotlb_sync(struct iommu_domain * io_domain,struct iommu_iotlb_gather * gather)695 static void ipmmu_iotlb_sync(struct iommu_domain *io_domain,
696 struct iommu_iotlb_gather *gather)
697 {
698 ipmmu_flush_iotlb_all(io_domain);
699 }
700
ipmmu_iova_to_phys(struct iommu_domain * io_domain,dma_addr_t iova)701 static phys_addr_t ipmmu_iova_to_phys(struct iommu_domain *io_domain,
702 dma_addr_t iova)
703 {
704 struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
705
706 /* TODO: Is locking needed ? */
707
708 return domain->iop->iova_to_phys(domain->iop, iova);
709 }
710
ipmmu_init_platform_device(struct device * dev,const struct of_phandle_args * args)711 static int ipmmu_init_platform_device(struct device *dev,
712 const struct of_phandle_args *args)
713 {
714 struct platform_device *ipmmu_pdev;
715
716 ipmmu_pdev = of_find_device_by_node(args->np);
717 if (!ipmmu_pdev)
718 return -ENODEV;
719
720 dev_iommu_priv_set(dev, platform_get_drvdata(ipmmu_pdev));
721
722 return 0;
723 }
724
725 static const struct soc_device_attribute soc_needs_opt_in[] = {
726 { .family = "R-Car Gen3", },
727 { .family = "R-Car Gen4", },
728 { .family = "RZ/G2", },
729 { /* sentinel */ }
730 };
731
732 static const struct soc_device_attribute soc_denylist[] = {
733 { .soc_id = "r8a774a1", },
734 { .soc_id = "r8a7795", .revision = "ES2.*" },
735 { .soc_id = "r8a7796", },
736 { /* sentinel */ }
737 };
738
739 static const char * const devices_allowlist[] = {
740 "ee100000.mmc",
741 "ee120000.mmc",
742 "ee140000.mmc",
743 "ee160000.mmc"
744 };
745
ipmmu_device_is_allowed(struct device * dev)746 static bool ipmmu_device_is_allowed(struct device *dev)
747 {
748 unsigned int i;
749
750 /*
751 * R-Car Gen3/4 and RZ/G2 use the allow list to opt-in devices.
752 * For Other SoCs, this returns true anyway.
753 */
754 if (!soc_device_match(soc_needs_opt_in))
755 return true;
756
757 /* Check whether this SoC can use the IPMMU correctly or not */
758 if (soc_device_match(soc_denylist))
759 return false;
760
761 /* Check whether this device is a PCI device */
762 if (dev_is_pci(dev))
763 return true;
764
765 /* Check whether this device can work with the IPMMU */
766 for (i = 0; i < ARRAY_SIZE(devices_allowlist); i++) {
767 if (!strcmp(dev_name(dev), devices_allowlist[i]))
768 return true;
769 }
770
771 /* Otherwise, do not allow use of IPMMU */
772 return false;
773 }
774
ipmmu_of_xlate(struct device * dev,const struct of_phandle_args * spec)775 static int ipmmu_of_xlate(struct device *dev,
776 const struct of_phandle_args *spec)
777 {
778 if (!ipmmu_device_is_allowed(dev))
779 return -ENODEV;
780
781 iommu_fwspec_add_ids(dev, spec->args, 1);
782
783 /* Initialize once - xlate() will call multiple times */
784 if (to_ipmmu(dev))
785 return 0;
786
787 return ipmmu_init_platform_device(dev, spec);
788 }
789
ipmmu_init_arm_mapping(struct device * dev)790 static int ipmmu_init_arm_mapping(struct device *dev)
791 {
792 struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
793 int ret;
794
795 /*
796 * Create the ARM mapping, used by the ARM DMA mapping core to allocate
797 * VAs. This will allocate a corresponding IOMMU domain.
798 *
799 * TODO:
800 * - Create one mapping per context (TLB).
801 * - Make the mapping size configurable ? We currently use a 2GB mapping
802 * at a 1GB offset to ensure that NULL VAs will fault.
803 */
804 if (!mmu->mapping) {
805 struct dma_iommu_mapping *mapping;
806
807 mapping = arm_iommu_create_mapping(dev, SZ_1G, SZ_2G);
808 if (IS_ERR(mapping)) {
809 dev_err(mmu->dev, "failed to create ARM IOMMU mapping\n");
810 ret = PTR_ERR(mapping);
811 goto error;
812 }
813
814 mmu->mapping = mapping;
815 }
816
817 /* Attach the ARM VA mapping to the device. */
818 ret = arm_iommu_attach_device(dev, mmu->mapping);
819 if (ret < 0) {
820 dev_err(dev, "Failed to attach device to VA mapping\n");
821 goto error;
822 }
823
824 return 0;
825
826 error:
827 if (mmu->mapping)
828 arm_iommu_release_mapping(mmu->mapping);
829
830 return ret;
831 }
832
ipmmu_probe_device(struct device * dev)833 static struct iommu_device *ipmmu_probe_device(struct device *dev)
834 {
835 struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
836
837 /*
838 * Only let through devices that have been verified in xlate()
839 */
840 if (!mmu)
841 return ERR_PTR(-ENODEV);
842
843 return &mmu->iommu;
844 }
845
ipmmu_probe_finalize(struct device * dev)846 static void ipmmu_probe_finalize(struct device *dev)
847 {
848 int ret = 0;
849
850 if (IS_ENABLED(CONFIG_ARM) && !IS_ENABLED(CONFIG_IOMMU_DMA))
851 ret = ipmmu_init_arm_mapping(dev);
852
853 if (ret)
854 dev_err(dev, "Can't create IOMMU mapping - DMA-OPS will not work\n");
855 }
856
ipmmu_release_device(struct device * dev)857 static void ipmmu_release_device(struct device *dev)
858 {
859 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
860 struct ipmmu_vmsa_device *mmu = to_ipmmu(dev);
861 unsigned int i;
862
863 for (i = 0; i < fwspec->num_ids; ++i) {
864 unsigned int utlb = fwspec->ids[i];
865
866 ipmmu_imuctr_write(mmu, utlb, 0);
867 mmu->utlb_ctx[utlb] = IPMMU_CTX_INVALID;
868 }
869
870 arm_iommu_release_mapping(mmu->mapping);
871 }
872
873 static const struct iommu_ops ipmmu_ops = {
874 .identity_domain = &ipmmu_iommu_identity_domain,
875 .domain_alloc_paging = ipmmu_domain_alloc_paging,
876 .probe_device = ipmmu_probe_device,
877 .release_device = ipmmu_release_device,
878 .probe_finalize = ipmmu_probe_finalize,
879 /*
880 * FIXME: The device grouping is a fixed property of the hardware's
881 * ability to isolate and control DMA, it should not depend on kconfig.
882 */
883 .device_group = IS_ENABLED(CONFIG_ARM) && !IS_ENABLED(CONFIG_IOMMU_DMA)
884 ? generic_device_group : generic_single_device_group,
885 .pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
886 .of_xlate = ipmmu_of_xlate,
887 .default_domain_ops = &(const struct iommu_domain_ops) {
888 .attach_dev = ipmmu_attach_device,
889 .map_pages = ipmmu_map,
890 .unmap_pages = ipmmu_unmap,
891 .flush_iotlb_all = ipmmu_flush_iotlb_all,
892 .iotlb_sync = ipmmu_iotlb_sync,
893 .iova_to_phys = ipmmu_iova_to_phys,
894 .free = ipmmu_domain_free,
895 }
896 };
897
898 /* -----------------------------------------------------------------------------
899 * Probe/remove and init
900 */
901
ipmmu_device_reset(struct ipmmu_vmsa_device * mmu)902 static void ipmmu_device_reset(struct ipmmu_vmsa_device *mmu)
903 {
904 unsigned int i;
905
906 /* Disable all contexts. */
907 for (i = 0; i < mmu->num_ctx; ++i)
908 ipmmu_ctx_write(mmu, i, IMCTR, 0);
909 }
910
911 static const struct ipmmu_features ipmmu_features_default = {
912 .use_ns_alias_offset = true,
913 .has_cache_leaf_nodes = false,
914 .number_of_contexts = 1, /* software only tested with one context */
915 .num_utlbs = 32,
916 .setup_imbuscr = true,
917 .twobit_imttbcr_sl0 = false,
918 .reserved_context = false,
919 .cache_snoop = true,
920 .ctx_offset_base = 0,
921 .ctx_offset_stride = 0x40,
922 .utlb_offset_base = 0,
923 };
924
925 static const struct ipmmu_features ipmmu_features_rcar_gen3 = {
926 .use_ns_alias_offset = false,
927 .has_cache_leaf_nodes = true,
928 .number_of_contexts = 8,
929 .num_utlbs = 48,
930 .setup_imbuscr = false,
931 .twobit_imttbcr_sl0 = true,
932 .reserved_context = true,
933 .cache_snoop = false,
934 .ctx_offset_base = 0,
935 .ctx_offset_stride = 0x40,
936 .utlb_offset_base = 0,
937 };
938
939 static const struct ipmmu_features ipmmu_features_rcar_gen4 = {
940 .use_ns_alias_offset = false,
941 .has_cache_leaf_nodes = true,
942 .number_of_contexts = 16,
943 .num_utlbs = 64,
944 .setup_imbuscr = false,
945 .twobit_imttbcr_sl0 = true,
946 .reserved_context = true,
947 .cache_snoop = false,
948 .ctx_offset_base = 0x10000,
949 .ctx_offset_stride = 0x1040,
950 .utlb_offset_base = 0x3000,
951 };
952
953 static const struct of_device_id ipmmu_of_ids[] = {
954 {
955 .compatible = "renesas,ipmmu-vmsa",
956 .data = &ipmmu_features_default,
957 }, {
958 .compatible = "renesas,ipmmu-r8a774a1",
959 .data = &ipmmu_features_rcar_gen3,
960 }, {
961 .compatible = "renesas,ipmmu-r8a774b1",
962 .data = &ipmmu_features_rcar_gen3,
963 }, {
964 .compatible = "renesas,ipmmu-r8a774c0",
965 .data = &ipmmu_features_rcar_gen3,
966 }, {
967 .compatible = "renesas,ipmmu-r8a774e1",
968 .data = &ipmmu_features_rcar_gen3,
969 }, {
970 .compatible = "renesas,ipmmu-r8a7795",
971 .data = &ipmmu_features_rcar_gen3,
972 }, {
973 .compatible = "renesas,ipmmu-r8a7796",
974 .data = &ipmmu_features_rcar_gen3,
975 }, {
976 .compatible = "renesas,ipmmu-r8a77961",
977 .data = &ipmmu_features_rcar_gen3,
978 }, {
979 .compatible = "renesas,ipmmu-r8a77965",
980 .data = &ipmmu_features_rcar_gen3,
981 }, {
982 .compatible = "renesas,ipmmu-r8a77970",
983 .data = &ipmmu_features_rcar_gen3,
984 }, {
985 .compatible = "renesas,ipmmu-r8a77980",
986 .data = &ipmmu_features_rcar_gen3,
987 }, {
988 .compatible = "renesas,ipmmu-r8a77990",
989 .data = &ipmmu_features_rcar_gen3,
990 }, {
991 .compatible = "renesas,ipmmu-r8a77995",
992 .data = &ipmmu_features_rcar_gen3,
993 }, {
994 .compatible = "renesas,ipmmu-r8a779a0",
995 .data = &ipmmu_features_rcar_gen4,
996 }, {
997 .compatible = "renesas,rcar-gen4-ipmmu-vmsa",
998 .data = &ipmmu_features_rcar_gen4,
999 }, {
1000 /* Terminator */
1001 },
1002 };
1003
ipmmu_probe(struct platform_device * pdev)1004 static int ipmmu_probe(struct platform_device *pdev)
1005 {
1006 struct ipmmu_vmsa_device *mmu;
1007 int irq;
1008 int ret;
1009
1010 mmu = devm_kzalloc(&pdev->dev, sizeof(*mmu), GFP_KERNEL);
1011 if (!mmu) {
1012 dev_err(&pdev->dev, "cannot allocate device data\n");
1013 return -ENOMEM;
1014 }
1015
1016 mmu->dev = &pdev->dev;
1017 spin_lock_init(&mmu->lock);
1018 bitmap_zero(mmu->ctx, IPMMU_CTX_MAX);
1019 mmu->features = of_device_get_match_data(&pdev->dev);
1020 memset(mmu->utlb_ctx, IPMMU_CTX_INVALID, mmu->features->num_utlbs);
1021 ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40));
1022 if (ret)
1023 return ret;
1024
1025 /* Map I/O memory and request IRQ. */
1026 mmu->base = devm_platform_ioremap_resource(pdev, 0);
1027 if (IS_ERR(mmu->base))
1028 return PTR_ERR(mmu->base);
1029
1030 /*
1031 * The IPMMU has two register banks, for secure and non-secure modes.
1032 * The bank mapped at the beginning of the IPMMU address space
1033 * corresponds to the running mode of the CPU. When running in secure
1034 * mode the non-secure register bank is also available at an offset.
1035 *
1036 * Secure mode operation isn't clearly documented and is thus currently
1037 * not implemented in the driver. Furthermore, preliminary tests of
1038 * non-secure operation with the main register bank were not successful.
1039 * Offset the registers base unconditionally to point to the non-secure
1040 * alias space for now.
1041 */
1042 if (mmu->features->use_ns_alias_offset)
1043 mmu->base += IM_NS_ALIAS_OFFSET;
1044
1045 mmu->num_ctx = min(IPMMU_CTX_MAX, mmu->features->number_of_contexts);
1046
1047 /*
1048 * Determine if this IPMMU instance is a root device by checking for
1049 * the lack of has_cache_leaf_nodes flag or renesas,ipmmu-main property.
1050 */
1051 if (!mmu->features->has_cache_leaf_nodes ||
1052 !of_property_present(pdev->dev.of_node, "renesas,ipmmu-main"))
1053 mmu->root = mmu;
1054 else
1055 mmu->root = ipmmu_find_root();
1056
1057 /*
1058 * Wait until the root device has been registered for sure.
1059 */
1060 if (!mmu->root)
1061 return -EPROBE_DEFER;
1062
1063 /* Root devices have mandatory IRQs */
1064 if (ipmmu_is_root(mmu)) {
1065 irq = platform_get_irq(pdev, 0);
1066 if (irq < 0)
1067 return irq;
1068
1069 ret = devm_request_irq(&pdev->dev, irq, ipmmu_irq, 0,
1070 dev_name(&pdev->dev), mmu);
1071 if (ret < 0) {
1072 dev_err(&pdev->dev, "failed to request IRQ %d\n", irq);
1073 return ret;
1074 }
1075
1076 ipmmu_device_reset(mmu);
1077
1078 if (mmu->features->reserved_context) {
1079 dev_info(&pdev->dev, "IPMMU context 0 is reserved\n");
1080 set_bit(0, mmu->ctx);
1081 }
1082 }
1083
1084 /*
1085 * Register the IPMMU to the IOMMU subsystem in the following cases:
1086 * - R-Car Gen2 IPMMU (all devices registered)
1087 * - R-Car Gen3 IPMMU (leaf devices only - skip root IPMMU-MM device)
1088 */
1089 if (!mmu->features->has_cache_leaf_nodes || !ipmmu_is_root(mmu)) {
1090 ret = iommu_device_sysfs_add(&mmu->iommu, &pdev->dev, NULL,
1091 dev_name(&pdev->dev));
1092 if (ret)
1093 return ret;
1094
1095 ret = iommu_device_register(&mmu->iommu, &ipmmu_ops, &pdev->dev);
1096 if (ret)
1097 return ret;
1098 }
1099
1100 /*
1101 * We can't create the ARM mapping here as it requires the bus to have
1102 * an IOMMU, which only happens when bus_set_iommu() is called in
1103 * ipmmu_init() after the probe function returns.
1104 */
1105
1106 platform_set_drvdata(pdev, mmu);
1107
1108 return 0;
1109 }
1110
ipmmu_remove(struct platform_device * pdev)1111 static void ipmmu_remove(struct platform_device *pdev)
1112 {
1113 struct ipmmu_vmsa_device *mmu = platform_get_drvdata(pdev);
1114
1115 iommu_device_sysfs_remove(&mmu->iommu);
1116 iommu_device_unregister(&mmu->iommu);
1117
1118 arm_iommu_release_mapping(mmu->mapping);
1119
1120 ipmmu_device_reset(mmu);
1121 }
1122
ipmmu_resume_noirq(struct device * dev)1123 static int ipmmu_resume_noirq(struct device *dev)
1124 {
1125 struct ipmmu_vmsa_device *mmu = dev_get_drvdata(dev);
1126 unsigned int i;
1127
1128 /* Reset root MMU and restore contexts */
1129 if (ipmmu_is_root(mmu)) {
1130 ipmmu_device_reset(mmu);
1131
1132 for (i = 0; i < mmu->num_ctx; i++) {
1133 if (!mmu->domains[i])
1134 continue;
1135
1136 ipmmu_domain_setup_context(mmu->domains[i]);
1137 }
1138 }
1139
1140 /* Re-enable active micro-TLBs */
1141 for (i = 0; i < mmu->features->num_utlbs; i++) {
1142 if (mmu->utlb_ctx[i] == IPMMU_CTX_INVALID)
1143 continue;
1144
1145 ipmmu_utlb_enable(mmu->root->domains[mmu->utlb_ctx[i]], i);
1146 }
1147
1148 return 0;
1149 }
1150
1151 static const struct dev_pm_ops ipmmu_pm = {
1152 NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, ipmmu_resume_noirq)
1153 };
1154
1155 static struct platform_driver ipmmu_driver = {
1156 .driver = {
1157 .name = "ipmmu-vmsa",
1158 .of_match_table = ipmmu_of_ids,
1159 .pm = pm_sleep_ptr(&ipmmu_pm),
1160 },
1161 .probe = ipmmu_probe,
1162 .remove = ipmmu_remove,
1163 };
1164 builtin_platform_driver(ipmmu_driver);
1165