xref: /openbmc/linux/drivers/iommu/sprd-iommu.c (revision 3b73c45e) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Unisoc IOMMU driver
4  *
5  * Copyright (C) 2020 Unisoc, Inc.
6  * Author: Chunyan Zhang <chunyan.zhang@unisoc.com>
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/device.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/errno.h>
13 #include <linux/iommu.h>
14 #include <linux/mfd/syscon.h>
15 #include <linux/module.h>
16 #include <linux/of_platform.h>
17 #include <linux/regmap.h>
18 #include <linux/slab.h>
19 
20 #define SPRD_IOMMU_PAGE_SHIFT	12
21 #define SPRD_IOMMU_PAGE_SIZE	SZ_4K
22 
23 #define SPRD_EX_CFG		0x0
24 #define SPRD_IOMMU_VAOR_BYPASS	BIT(4)
25 #define SPRD_IOMMU_GATE_EN	BIT(1)
26 #define SPRD_IOMMU_EN		BIT(0)
27 #define SPRD_EX_UPDATE		0x4
28 #define SPRD_EX_FIRST_VPN	0x8
29 #define SPRD_EX_VPN_RANGE	0xc
30 #define SPRD_EX_FIRST_PPN	0x10
31 #define SPRD_EX_DEFAULT_PPN	0x14
32 
33 #define SPRD_IOMMU_VERSION	0x0
34 #define SPRD_VERSION_MASK	GENMASK(15, 8)
35 #define SPRD_VERSION_SHIFT	0x8
36 #define SPRD_VAU_CFG		0x4
37 #define SPRD_VAU_UPDATE		0x8
38 #define SPRD_VAU_AUTH_CFG	0xc
39 #define SPRD_VAU_FIRST_PPN	0x10
40 #define SPRD_VAU_DEFAULT_PPN_RD	0x14
41 #define SPRD_VAU_DEFAULT_PPN_WR	0x18
42 #define SPRD_VAU_FIRST_VPN	0x1c
43 #define SPRD_VAU_VPN_RANGE	0x20
44 
45 enum sprd_iommu_version {
46 	SPRD_IOMMU_EX,
47 	SPRD_IOMMU_VAU,
48 };
49 
50 /*
51  * struct sprd_iommu_device - high-level sprd IOMMU device representation,
52  * including hardware information and configuration, also driver data, etc
53  *
54  * @ver: sprd IOMMU IP version
55  * @prot_page_va: protect page base virtual address
56  * @prot_page_pa: protect page base physical address, data would be
57  *		  written to here while translation fault
58  * @base: mapped base address for accessing registers
59  * @dev: pointer to basic device structure
60  * @iommu: IOMMU core representation
61  * @group: IOMMU group
62  * @eb: gate clock which controls IOMMU access
63  */
64 struct sprd_iommu_device {
65 	enum sprd_iommu_version	ver;
66 	u32			*prot_page_va;
67 	dma_addr_t		prot_page_pa;
68 	void __iomem		*base;
69 	struct device		*dev;
70 	struct iommu_device	iommu;
71 	struct iommu_group	*group;
72 	struct clk		*eb;
73 };
74 
75 struct sprd_iommu_domain {
76 	spinlock_t		pgtlock; /* lock for page table */
77 	struct iommu_domain	domain;
78 	u32			*pgt_va; /* page table virtual address base */
79 	dma_addr_t		pgt_pa; /* page table physical address base */
80 	struct sprd_iommu_device	*sdev;
81 };
82 
83 static const struct iommu_ops sprd_iommu_ops;
84 
85 static struct sprd_iommu_domain *to_sprd_domain(struct iommu_domain *dom)
86 {
87 	return container_of(dom, struct sprd_iommu_domain, domain);
88 }
89 
90 static inline void
91 sprd_iommu_write(struct sprd_iommu_device *sdev, unsigned int reg, u32 val)
92 {
93 	writel_relaxed(val, sdev->base + reg);
94 }
95 
96 static inline u32
97 sprd_iommu_read(struct sprd_iommu_device *sdev, unsigned int reg)
98 {
99 	return readl_relaxed(sdev->base + reg);
100 }
101 
102 static inline void
103 sprd_iommu_update_bits(struct sprd_iommu_device *sdev, unsigned int reg,
104 		  u32 mask, u32 shift, u32 val)
105 {
106 	u32 t = sprd_iommu_read(sdev, reg);
107 
108 	t = (t & (~(mask << shift))) | ((val & mask) << shift);
109 	sprd_iommu_write(sdev, reg, t);
110 }
111 
112 static inline int
113 sprd_iommu_get_version(struct sprd_iommu_device *sdev)
114 {
115 	int ver = (sprd_iommu_read(sdev, SPRD_IOMMU_VERSION) &
116 		   SPRD_VERSION_MASK) >> SPRD_VERSION_SHIFT;
117 
118 	switch (ver) {
119 	case SPRD_IOMMU_EX:
120 	case SPRD_IOMMU_VAU:
121 		return ver;
122 	default:
123 		return -EINVAL;
124 	}
125 }
126 
127 static size_t
128 sprd_iommu_pgt_size(struct iommu_domain *domain)
129 {
130 	return ((domain->geometry.aperture_end -
131 		 domain->geometry.aperture_start + 1) >>
132 		SPRD_IOMMU_PAGE_SHIFT) * sizeof(u32);
133 }
134 
135 static struct iommu_domain *sprd_iommu_domain_alloc(unsigned int domain_type)
136 {
137 	struct sprd_iommu_domain *dom;
138 
139 	if (domain_type != IOMMU_DOMAIN_DMA && domain_type != IOMMU_DOMAIN_UNMANAGED)
140 		return NULL;
141 
142 	dom = kzalloc(sizeof(*dom), GFP_KERNEL);
143 	if (!dom)
144 		return NULL;
145 
146 	spin_lock_init(&dom->pgtlock);
147 
148 	dom->domain.geometry.aperture_start = 0;
149 	dom->domain.geometry.aperture_end = SZ_256M - 1;
150 
151 	return &dom->domain;
152 }
153 
154 static void sprd_iommu_domain_free(struct iommu_domain *domain)
155 {
156 	struct sprd_iommu_domain *dom = to_sprd_domain(domain);
157 
158 	kfree(dom);
159 }
160 
161 static void sprd_iommu_first_vpn(struct sprd_iommu_domain *dom)
162 {
163 	struct sprd_iommu_device *sdev = dom->sdev;
164 	u32 val;
165 	unsigned int reg;
166 
167 	if (sdev->ver == SPRD_IOMMU_EX)
168 		reg = SPRD_EX_FIRST_VPN;
169 	else
170 		reg = SPRD_VAU_FIRST_VPN;
171 
172 	val = dom->domain.geometry.aperture_start >> SPRD_IOMMU_PAGE_SHIFT;
173 	sprd_iommu_write(sdev, reg, val);
174 }
175 
176 static void sprd_iommu_vpn_range(struct sprd_iommu_domain *dom)
177 {
178 	struct sprd_iommu_device *sdev = dom->sdev;
179 	u32 val;
180 	unsigned int reg;
181 
182 	if (sdev->ver == SPRD_IOMMU_EX)
183 		reg = SPRD_EX_VPN_RANGE;
184 	else
185 		reg = SPRD_VAU_VPN_RANGE;
186 
187 	val = (dom->domain.geometry.aperture_end -
188 	       dom->domain.geometry.aperture_start) >> SPRD_IOMMU_PAGE_SHIFT;
189 	sprd_iommu_write(sdev, reg, val);
190 }
191 
192 static void sprd_iommu_first_ppn(struct sprd_iommu_domain *dom)
193 {
194 	u32 val = dom->pgt_pa >> SPRD_IOMMU_PAGE_SHIFT;
195 	struct sprd_iommu_device *sdev = dom->sdev;
196 	unsigned int reg;
197 
198 	if (sdev->ver == SPRD_IOMMU_EX)
199 		reg = SPRD_EX_FIRST_PPN;
200 	else
201 		reg = SPRD_VAU_FIRST_PPN;
202 
203 	sprd_iommu_write(sdev, reg, val);
204 }
205 
206 static void sprd_iommu_default_ppn(struct sprd_iommu_device *sdev)
207 {
208 	u32 val = sdev->prot_page_pa >> SPRD_IOMMU_PAGE_SHIFT;
209 
210 	if (sdev->ver == SPRD_IOMMU_EX) {
211 		sprd_iommu_write(sdev, SPRD_EX_DEFAULT_PPN, val);
212 	} else if (sdev->ver == SPRD_IOMMU_VAU) {
213 		sprd_iommu_write(sdev, SPRD_VAU_DEFAULT_PPN_RD, val);
214 		sprd_iommu_write(sdev, SPRD_VAU_DEFAULT_PPN_WR, val);
215 	}
216 }
217 
218 static void sprd_iommu_hw_en(struct sprd_iommu_device *sdev, bool en)
219 {
220 	unsigned int reg_cfg;
221 	u32 mask, val;
222 
223 	if (sdev->ver == SPRD_IOMMU_EX)
224 		reg_cfg = SPRD_EX_CFG;
225 	else
226 		reg_cfg = SPRD_VAU_CFG;
227 
228 	mask = SPRD_IOMMU_EN | SPRD_IOMMU_GATE_EN;
229 	val = en ? mask : 0;
230 	sprd_iommu_update_bits(sdev, reg_cfg, mask, 0, val);
231 }
232 
233 static int sprd_iommu_attach_device(struct iommu_domain *domain,
234 				    struct device *dev)
235 {
236 	struct sprd_iommu_device *sdev = dev_iommu_priv_get(dev);
237 	struct sprd_iommu_domain *dom = to_sprd_domain(domain);
238 	size_t pgt_size = sprd_iommu_pgt_size(domain);
239 
240 	if (dom->sdev) {
241 		pr_err("There's already a device attached to this domain.\n");
242 		return -EINVAL;
243 	}
244 
245 	dom->pgt_va = dma_alloc_coherent(sdev->dev, pgt_size, &dom->pgt_pa, GFP_KERNEL);
246 	if (!dom->pgt_va)
247 		return -ENOMEM;
248 
249 	dom->sdev = sdev;
250 
251 	sprd_iommu_first_ppn(dom);
252 	sprd_iommu_first_vpn(dom);
253 	sprd_iommu_vpn_range(dom);
254 	sprd_iommu_default_ppn(sdev);
255 	sprd_iommu_hw_en(sdev, true);
256 
257 	return 0;
258 }
259 
260 static void sprd_iommu_detach_device(struct iommu_domain *domain,
261 					     struct device *dev)
262 {
263 	struct sprd_iommu_domain *dom = to_sprd_domain(domain);
264 	struct sprd_iommu_device *sdev = dom->sdev;
265 	size_t pgt_size = sprd_iommu_pgt_size(domain);
266 
267 	if (!sdev)
268 		return;
269 
270 	dma_free_coherent(sdev->dev, pgt_size, dom->pgt_va, dom->pgt_pa);
271 	sprd_iommu_hw_en(sdev, false);
272 	dom->sdev = NULL;
273 }
274 
275 static int sprd_iommu_map(struct iommu_domain *domain, unsigned long iova,
276 			  phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
277 {
278 	struct sprd_iommu_domain *dom = to_sprd_domain(domain);
279 	unsigned int page_num = size >> SPRD_IOMMU_PAGE_SHIFT;
280 	unsigned long flags;
281 	unsigned int i;
282 	u32 *pgt_base_iova;
283 	u32 pabase = (u32)paddr;
284 	unsigned long start = domain->geometry.aperture_start;
285 	unsigned long end = domain->geometry.aperture_end;
286 
287 	if (!dom->sdev) {
288 		pr_err("No sprd_iommu_device attached to the domain\n");
289 		return -EINVAL;
290 	}
291 
292 	if (iova < start || (iova + size) > (end + 1)) {
293 		dev_err(dom->sdev->dev, "(iova(0x%lx) + size(%zx)) are not in the range!\n",
294 			iova, size);
295 		return -EINVAL;
296 	}
297 
298 	pgt_base_iova = dom->pgt_va + ((iova - start) >> SPRD_IOMMU_PAGE_SHIFT);
299 
300 	spin_lock_irqsave(&dom->pgtlock, flags);
301 	for (i = 0; i < page_num; i++) {
302 		pgt_base_iova[i] = pabase >> SPRD_IOMMU_PAGE_SHIFT;
303 		pabase += SPRD_IOMMU_PAGE_SIZE;
304 	}
305 	spin_unlock_irqrestore(&dom->pgtlock, flags);
306 
307 	return 0;
308 }
309 
310 static size_t sprd_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
311 			size_t size, struct iommu_iotlb_gather *iotlb_gather)
312 {
313 	struct sprd_iommu_domain *dom = to_sprd_domain(domain);
314 	unsigned long flags;
315 	u32 *pgt_base_iova;
316 	unsigned int page_num = size >> SPRD_IOMMU_PAGE_SHIFT;
317 	unsigned long start = domain->geometry.aperture_start;
318 	unsigned long end = domain->geometry.aperture_end;
319 
320 	if (iova < start || (iova + size) > (end + 1))
321 		return -EINVAL;
322 
323 	pgt_base_iova = dom->pgt_va + ((iova - start) >> SPRD_IOMMU_PAGE_SHIFT);
324 
325 	spin_lock_irqsave(&dom->pgtlock, flags);
326 	memset(pgt_base_iova, 0, page_num * sizeof(u32));
327 	spin_unlock_irqrestore(&dom->pgtlock, flags);
328 
329 	return 0;
330 }
331 
332 static void sprd_iommu_sync_map(struct iommu_domain *domain,
333 				unsigned long iova, size_t size)
334 {
335 	struct sprd_iommu_domain *dom = to_sprd_domain(domain);
336 	unsigned int reg;
337 
338 	if (dom->sdev->ver == SPRD_IOMMU_EX)
339 		reg = SPRD_EX_UPDATE;
340 	else
341 		reg = SPRD_VAU_UPDATE;
342 
343 	/* clear IOMMU TLB buffer after page table updated */
344 	sprd_iommu_write(dom->sdev, reg, 0xffffffff);
345 }
346 
347 static void sprd_iommu_sync(struct iommu_domain *domain,
348 			    struct iommu_iotlb_gather *iotlb_gather)
349 {
350 	sprd_iommu_sync_map(domain, 0, 0);
351 }
352 
353 static phys_addr_t sprd_iommu_iova_to_phys(struct iommu_domain *domain,
354 					   dma_addr_t iova)
355 {
356 	struct sprd_iommu_domain *dom = to_sprd_domain(domain);
357 	unsigned long flags;
358 	phys_addr_t pa;
359 	unsigned long start = domain->geometry.aperture_start;
360 	unsigned long end = domain->geometry.aperture_end;
361 
362 	if (WARN_ON(iova < start || iova > end))
363 		return 0;
364 
365 	spin_lock_irqsave(&dom->pgtlock, flags);
366 	pa = *(dom->pgt_va + ((iova - start) >> SPRD_IOMMU_PAGE_SHIFT));
367 	pa = (pa << SPRD_IOMMU_PAGE_SHIFT) + ((iova - start) & (SPRD_IOMMU_PAGE_SIZE - 1));
368 	spin_unlock_irqrestore(&dom->pgtlock, flags);
369 
370 	return pa;
371 }
372 
373 static struct iommu_device *sprd_iommu_probe_device(struct device *dev)
374 {
375 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
376 	struct sprd_iommu_device *sdev;
377 
378 	if (!fwspec || fwspec->ops != &sprd_iommu_ops)
379 		return ERR_PTR(-ENODEV);
380 
381 	sdev = dev_iommu_priv_get(dev);
382 
383 	return &sdev->iommu;
384 }
385 
386 static struct iommu_group *sprd_iommu_device_group(struct device *dev)
387 {
388 	struct sprd_iommu_device *sdev = dev_iommu_priv_get(dev);
389 
390 	return iommu_group_ref_get(sdev->group);
391 }
392 
393 static int sprd_iommu_of_xlate(struct device *dev, struct of_phandle_args *args)
394 {
395 	struct platform_device *pdev;
396 
397 	if (!dev_iommu_priv_get(dev)) {
398 		pdev = of_find_device_by_node(args->np);
399 		dev_iommu_priv_set(dev, platform_get_drvdata(pdev));
400 		platform_device_put(pdev);
401 	}
402 
403 	return 0;
404 }
405 
406 
407 static const struct iommu_ops sprd_iommu_ops = {
408 	.domain_alloc	= sprd_iommu_domain_alloc,
409 	.probe_device	= sprd_iommu_probe_device,
410 	.device_group	= sprd_iommu_device_group,
411 	.of_xlate	= sprd_iommu_of_xlate,
412 	.pgsize_bitmap	= ~0UL << SPRD_IOMMU_PAGE_SHIFT,
413 	.owner		= THIS_MODULE,
414 	.default_domain_ops = &(const struct iommu_domain_ops) {
415 		.attach_dev	= sprd_iommu_attach_device,
416 		.detach_dev	= sprd_iommu_detach_device,
417 		.map		= sprd_iommu_map,
418 		.unmap		= sprd_iommu_unmap,
419 		.iotlb_sync_map	= sprd_iommu_sync_map,
420 		.iotlb_sync	= sprd_iommu_sync,
421 		.iova_to_phys	= sprd_iommu_iova_to_phys,
422 		.free		= sprd_iommu_domain_free,
423 	}
424 };
425 
426 static const struct of_device_id sprd_iommu_of_match[] = {
427 	{ .compatible = "sprd,iommu-v1" },
428 	{ },
429 };
430 MODULE_DEVICE_TABLE(of, sprd_iommu_of_match);
431 
432 /*
433  * Clock is not required, access to some of IOMMUs is controlled by gate
434  * clk, enabled clocks for that kind of IOMMUs before accessing.
435  * Return 0 for success or no clocks found.
436  */
437 static int sprd_iommu_clk_enable(struct sprd_iommu_device *sdev)
438 {
439 	struct clk *eb;
440 
441 	eb = devm_clk_get_optional(sdev->dev, NULL);
442 	if (!eb)
443 		return 0;
444 
445 	if (IS_ERR(eb))
446 		return PTR_ERR(eb);
447 
448 	sdev->eb = eb;
449 	return clk_prepare_enable(eb);
450 }
451 
452 static void sprd_iommu_clk_disable(struct sprd_iommu_device *sdev)
453 {
454 	if (sdev->eb)
455 		clk_disable_unprepare(sdev->eb);
456 }
457 
458 static int sprd_iommu_probe(struct platform_device *pdev)
459 {
460 	struct sprd_iommu_device *sdev;
461 	struct device *dev = &pdev->dev;
462 	void __iomem *base;
463 	int ret;
464 
465 	sdev = devm_kzalloc(dev, sizeof(*sdev), GFP_KERNEL);
466 	if (!sdev)
467 		return -ENOMEM;
468 
469 	base = devm_platform_ioremap_resource(pdev, 0);
470 	if (IS_ERR(base)) {
471 		dev_err(dev, "Failed to get ioremap resource.\n");
472 		return PTR_ERR(base);
473 	}
474 	sdev->base = base;
475 
476 	sdev->prot_page_va = dma_alloc_coherent(dev, SPRD_IOMMU_PAGE_SIZE,
477 						&sdev->prot_page_pa, GFP_KERNEL);
478 	if (!sdev->prot_page_va)
479 		return -ENOMEM;
480 
481 	platform_set_drvdata(pdev, sdev);
482 	sdev->dev = dev;
483 
484 	/* All the client devices are in the same iommu-group */
485 	sdev->group = iommu_group_alloc();
486 	if (IS_ERR(sdev->group)) {
487 		ret = PTR_ERR(sdev->group);
488 		goto free_page;
489 	}
490 
491 	ret = iommu_device_sysfs_add(&sdev->iommu, dev, NULL, dev_name(dev));
492 	if (ret)
493 		goto put_group;
494 
495 	ret = iommu_device_register(&sdev->iommu, &sprd_iommu_ops, dev);
496 	if (ret)
497 		goto remove_sysfs;
498 
499 	if (!iommu_present(&platform_bus_type))
500 		bus_set_iommu(&platform_bus_type, &sprd_iommu_ops);
501 
502 	ret = sprd_iommu_clk_enable(sdev);
503 	if (ret)
504 		goto unregister_iommu;
505 
506 	ret = sprd_iommu_get_version(sdev);
507 	if (ret < 0) {
508 		dev_err(dev, "IOMMU version(%d) is invalid.\n", ret);
509 		goto disable_clk;
510 	}
511 	sdev->ver = ret;
512 
513 	return 0;
514 
515 disable_clk:
516 	sprd_iommu_clk_disable(sdev);
517 unregister_iommu:
518 	iommu_device_unregister(&sdev->iommu);
519 remove_sysfs:
520 	iommu_device_sysfs_remove(&sdev->iommu);
521 put_group:
522 	iommu_group_put(sdev->group);
523 free_page:
524 	dma_free_coherent(sdev->dev, SPRD_IOMMU_PAGE_SIZE, sdev->prot_page_va, sdev->prot_page_pa);
525 	return ret;
526 }
527 
528 static int sprd_iommu_remove(struct platform_device *pdev)
529 {
530 	struct sprd_iommu_device *sdev = platform_get_drvdata(pdev);
531 
532 	dma_free_coherent(sdev->dev, SPRD_IOMMU_PAGE_SIZE, sdev->prot_page_va, sdev->prot_page_pa);
533 
534 	iommu_group_put(sdev->group);
535 	sdev->group = NULL;
536 
537 	bus_set_iommu(&platform_bus_type, NULL);
538 
539 	platform_set_drvdata(pdev, NULL);
540 	iommu_device_sysfs_remove(&sdev->iommu);
541 	iommu_device_unregister(&sdev->iommu);
542 
543 	return 0;
544 }
545 
546 static struct platform_driver sprd_iommu_driver = {
547 	.driver	= {
548 		.name		= "sprd-iommu",
549 		.of_match_table	= sprd_iommu_of_match,
550 		.suppress_bind_attrs = true,
551 	},
552 	.probe	= sprd_iommu_probe,
553 	.remove	= sprd_iommu_remove,
554 };
555 module_platform_driver(sprd_iommu_driver);
556 
557 MODULE_DESCRIPTION("IOMMU driver for Unisoc SoCs");
558 MODULE_ALIAS("platform:sprd-iommu");
559 MODULE_LICENSE("GPL");
560