1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *
4  * Copyright (C) 2013 Freescale Semiconductor, Inc.
5  * Author: Varun Sethi <varun.sethi@freescale.com>
6  */
7 
8 #define pr_fmt(fmt)    "fsl-pamu-domain: %s: " fmt, __func__
9 
10 #include "fsl_pamu_domain.h"
11 
12 #include <sysdev/fsl_pci.h>
13 
14 /*
15  * Global spinlock that needs to be held while
16  * configuring PAMU.
17  */
18 static DEFINE_SPINLOCK(iommu_lock);
19 
20 static struct kmem_cache *fsl_pamu_domain_cache;
21 static struct kmem_cache *iommu_devinfo_cache;
22 static DEFINE_SPINLOCK(device_domain_lock);
23 
24 struct iommu_device pamu_iommu;	/* IOMMU core code handle */
25 
26 static struct fsl_dma_domain *to_fsl_dma_domain(struct iommu_domain *dom)
27 {
28 	return container_of(dom, struct fsl_dma_domain, iommu_domain);
29 }
30 
31 static int __init iommu_init_mempool(void)
32 {
33 	fsl_pamu_domain_cache = kmem_cache_create("fsl_pamu_domain",
34 						  sizeof(struct fsl_dma_domain),
35 						  0,
36 						  SLAB_HWCACHE_ALIGN,
37 						  NULL);
38 	if (!fsl_pamu_domain_cache) {
39 		pr_debug("Couldn't create fsl iommu_domain cache\n");
40 		return -ENOMEM;
41 	}
42 
43 	iommu_devinfo_cache = kmem_cache_create("iommu_devinfo",
44 						sizeof(struct device_domain_info),
45 						0,
46 						SLAB_HWCACHE_ALIGN,
47 						NULL);
48 	if (!iommu_devinfo_cache) {
49 		pr_debug("Couldn't create devinfo cache\n");
50 		kmem_cache_destroy(fsl_pamu_domain_cache);
51 		return -ENOMEM;
52 	}
53 
54 	return 0;
55 }
56 
57 static int update_liodn_stash(int liodn, struct fsl_dma_domain *dma_domain,
58 			      u32 val)
59 {
60 	int ret = 0;
61 	unsigned long flags;
62 
63 	spin_lock_irqsave(&iommu_lock, flags);
64 	ret = pamu_update_paace_stash(liodn, val);
65 	if (ret) {
66 		pr_debug("Failed to update SPAACE for liodn %d\n ", liodn);
67 		spin_unlock_irqrestore(&iommu_lock, flags);
68 		return ret;
69 	}
70 
71 	spin_unlock_irqrestore(&iommu_lock, flags);
72 
73 	return ret;
74 }
75 
76 /* Set the geometry parameters for a LIODN */
77 static int pamu_set_liodn(struct fsl_dma_domain *dma_domain, struct device *dev,
78 			  int liodn)
79 {
80 	u32 omi_index = ~(u32)0;
81 	unsigned long flags;
82 	int ret;
83 
84 	/*
85 	 * Configure the omi_index at the geometry setup time.
86 	 * This is a static value which depends on the type of
87 	 * device and would not change thereafter.
88 	 */
89 	get_ome_index(&omi_index, dev);
90 
91 	spin_lock_irqsave(&iommu_lock, flags);
92 	ret = pamu_disable_liodn(liodn);
93 	if (ret)
94 		goto out_unlock;
95 	ret = pamu_config_ppaace(liodn, omi_index, dma_domain->stash_id, 0);
96 	if (ret)
97 		goto out_unlock;
98 	ret = pamu_config_ppaace(liodn, ~(u32)0, dma_domain->stash_id,
99 				 PAACE_AP_PERMS_QUERY | PAACE_AP_PERMS_UPDATE);
100 out_unlock:
101 	spin_unlock_irqrestore(&iommu_lock, flags);
102 	if (ret) {
103 		pr_debug("PAACE configuration failed for liodn %d\n",
104 			 liodn);
105 	}
106 	return ret;
107 }
108 
109 static void remove_device_ref(struct device_domain_info *info)
110 {
111 	unsigned long flags;
112 
113 	list_del(&info->link);
114 	spin_lock_irqsave(&iommu_lock, flags);
115 	pamu_disable_liodn(info->liodn);
116 	spin_unlock_irqrestore(&iommu_lock, flags);
117 	spin_lock_irqsave(&device_domain_lock, flags);
118 	dev_iommu_priv_set(info->dev, NULL);
119 	kmem_cache_free(iommu_devinfo_cache, info);
120 	spin_unlock_irqrestore(&device_domain_lock, flags);
121 }
122 
123 static void detach_device(struct device *dev, struct fsl_dma_domain *dma_domain)
124 {
125 	struct device_domain_info *info, *tmp;
126 	unsigned long flags;
127 
128 	spin_lock_irqsave(&dma_domain->domain_lock, flags);
129 	/* Remove the device from the domain device list */
130 	list_for_each_entry_safe(info, tmp, &dma_domain->devices, link) {
131 		if (!dev || (info->dev == dev))
132 			remove_device_ref(info);
133 	}
134 	spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
135 }
136 
137 static void attach_device(struct fsl_dma_domain *dma_domain, int liodn, struct device *dev)
138 {
139 	struct device_domain_info *info, *old_domain_info;
140 	unsigned long flags;
141 
142 	spin_lock_irqsave(&device_domain_lock, flags);
143 	/*
144 	 * Check here if the device is already attached to domain or not.
145 	 * If the device is already attached to a domain detach it.
146 	 */
147 	old_domain_info = dev_iommu_priv_get(dev);
148 	if (old_domain_info && old_domain_info->domain != dma_domain) {
149 		spin_unlock_irqrestore(&device_domain_lock, flags);
150 		detach_device(dev, old_domain_info->domain);
151 		spin_lock_irqsave(&device_domain_lock, flags);
152 	}
153 
154 	info = kmem_cache_zalloc(iommu_devinfo_cache, GFP_ATOMIC);
155 
156 	info->dev = dev;
157 	info->liodn = liodn;
158 	info->domain = dma_domain;
159 
160 	list_add(&info->link, &dma_domain->devices);
161 	/*
162 	 * In case of devices with multiple LIODNs just store
163 	 * the info for the first LIODN as all
164 	 * LIODNs share the same domain
165 	 */
166 	if (!dev_iommu_priv_get(dev))
167 		dev_iommu_priv_set(dev, info);
168 	spin_unlock_irqrestore(&device_domain_lock, flags);
169 }
170 
171 static phys_addr_t fsl_pamu_iova_to_phys(struct iommu_domain *domain,
172 					 dma_addr_t iova)
173 {
174 	if (iova < domain->geometry.aperture_start ||
175 	    iova > domain->geometry.aperture_end)
176 		return 0;
177 	return iova;
178 }
179 
180 static bool fsl_pamu_capable(enum iommu_cap cap)
181 {
182 	return cap == IOMMU_CAP_CACHE_COHERENCY;
183 }
184 
185 static void fsl_pamu_domain_free(struct iommu_domain *domain)
186 {
187 	struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);
188 
189 	/* remove all the devices from the device list */
190 	detach_device(NULL, dma_domain);
191 	kmem_cache_free(fsl_pamu_domain_cache, dma_domain);
192 }
193 
194 static struct iommu_domain *fsl_pamu_domain_alloc(unsigned type)
195 {
196 	struct fsl_dma_domain *dma_domain;
197 
198 	if (type != IOMMU_DOMAIN_UNMANAGED)
199 		return NULL;
200 
201 	dma_domain = kmem_cache_zalloc(fsl_pamu_domain_cache, GFP_KERNEL);
202 	if (!dma_domain)
203 		return NULL;
204 
205 	dma_domain->stash_id = ~(u32)0;
206 	INIT_LIST_HEAD(&dma_domain->devices);
207 	spin_lock_init(&dma_domain->domain_lock);
208 
209 	/* default geometry 64 GB i.e. maximum system address */
210 	dma_domain->iommu_domain. geometry.aperture_start = 0;
211 	dma_domain->iommu_domain.geometry.aperture_end = (1ULL << 36) - 1;
212 	dma_domain->iommu_domain.geometry.force_aperture = true;
213 
214 	return &dma_domain->iommu_domain;
215 }
216 
217 /* Update stash destination for all LIODNs associated with the domain */
218 static int update_domain_stash(struct fsl_dma_domain *dma_domain, u32 val)
219 {
220 	struct device_domain_info *info;
221 	int ret = 0;
222 
223 	list_for_each_entry(info, &dma_domain->devices, link) {
224 		ret = update_liodn_stash(info->liodn, dma_domain, val);
225 		if (ret)
226 			break;
227 	}
228 
229 	return ret;
230 }
231 
232 static int fsl_pamu_attach_device(struct iommu_domain *domain,
233 				  struct device *dev)
234 {
235 	struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);
236 	unsigned long flags;
237 	int len, ret = 0, i;
238 	const u32 *liodn;
239 	struct pci_dev *pdev = NULL;
240 	struct pci_controller *pci_ctl;
241 
242 	/*
243 	 * Use LIODN of the PCI controller while attaching a
244 	 * PCI device.
245 	 */
246 	if (dev_is_pci(dev)) {
247 		pdev = to_pci_dev(dev);
248 		pci_ctl = pci_bus_to_host(pdev->bus);
249 		/*
250 		 * make dev point to pci controller device
251 		 * so we can get the LIODN programmed by
252 		 * u-boot.
253 		 */
254 		dev = pci_ctl->parent;
255 	}
256 
257 	liodn = of_get_property(dev->of_node, "fsl,liodn", &len);
258 	if (!liodn) {
259 		pr_debug("missing fsl,liodn property at %pOF\n", dev->of_node);
260 		return -EINVAL;
261 	}
262 
263 	spin_lock_irqsave(&dma_domain->domain_lock, flags);
264 	for (i = 0; i < len / sizeof(u32); i++) {
265 		/* Ensure that LIODN value is valid */
266 		if (liodn[i] >= PAACE_NUMBER_ENTRIES) {
267 			pr_debug("Invalid liodn %d, attach device failed for %pOF\n",
268 				 liodn[i], dev->of_node);
269 			ret = -EINVAL;
270 			break;
271 		}
272 
273 		attach_device(dma_domain, liodn[i], dev);
274 		ret = pamu_set_liodn(dma_domain, dev, liodn[i]);
275 		if (ret)
276 			break;
277 		ret = pamu_enable_liodn(liodn[i]);
278 		if (ret)
279 			break;
280 	}
281 	spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
282 	return ret;
283 }
284 
285 static void fsl_pamu_detach_device(struct iommu_domain *domain,
286 				   struct device *dev)
287 {
288 	struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);
289 	const u32 *prop;
290 	int len;
291 	struct pci_dev *pdev = NULL;
292 	struct pci_controller *pci_ctl;
293 
294 	/*
295 	 * Use LIODN of the PCI controller while detaching a
296 	 * PCI device.
297 	 */
298 	if (dev_is_pci(dev)) {
299 		pdev = to_pci_dev(dev);
300 		pci_ctl = pci_bus_to_host(pdev->bus);
301 		/*
302 		 * make dev point to pci controller device
303 		 * so we can get the LIODN programmed by
304 		 * u-boot.
305 		 */
306 		dev = pci_ctl->parent;
307 	}
308 
309 	prop = of_get_property(dev->of_node, "fsl,liodn", &len);
310 	if (prop)
311 		detach_device(dev, dma_domain);
312 	else
313 		pr_debug("missing fsl,liodn property at %pOF\n", dev->of_node);
314 }
315 
316 /* Set the domain stash attribute */
317 int fsl_pamu_configure_l1_stash(struct iommu_domain *domain, u32 cpu)
318 {
319 	struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);
320 	unsigned long flags;
321 	int ret;
322 
323 	spin_lock_irqsave(&dma_domain->domain_lock, flags);
324 	dma_domain->stash_id = get_stash_id(PAMU_ATTR_CACHE_L1, cpu);
325 	if (dma_domain->stash_id == ~(u32)0) {
326 		pr_debug("Invalid stash attributes\n");
327 		spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
328 		return -EINVAL;
329 	}
330 	ret = update_domain_stash(dma_domain, dma_domain->stash_id);
331 	spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
332 
333 	return ret;
334 }
335 
336 static struct iommu_group *get_device_iommu_group(struct device *dev)
337 {
338 	struct iommu_group *group;
339 
340 	group = iommu_group_get(dev);
341 	if (!group)
342 		group = iommu_group_alloc();
343 
344 	return group;
345 }
346 
347 static  bool check_pci_ctl_endpt_part(struct pci_controller *pci_ctl)
348 {
349 	u32 version;
350 
351 	/* Check the PCI controller version number by readding BRR1 register */
352 	version = in_be32(pci_ctl->cfg_addr + (PCI_FSL_BRR1 >> 2));
353 	version &= PCI_FSL_BRR1_VER;
354 	/* If PCI controller version is >= 0x204 we can partition endpoints */
355 	return version >= 0x204;
356 }
357 
358 /* Get iommu group information from peer devices or devices on the parent bus */
359 static struct iommu_group *get_shared_pci_device_group(struct pci_dev *pdev)
360 {
361 	struct pci_dev *tmp;
362 	struct iommu_group *group;
363 	struct pci_bus *bus = pdev->bus;
364 
365 	/*
366 	 * Traverese the pci bus device list to get
367 	 * the shared iommu group.
368 	 */
369 	while (bus) {
370 		list_for_each_entry(tmp, &bus->devices, bus_list) {
371 			if (tmp == pdev)
372 				continue;
373 			group = iommu_group_get(&tmp->dev);
374 			if (group)
375 				return group;
376 		}
377 
378 		bus = bus->parent;
379 	}
380 
381 	return NULL;
382 }
383 
384 static struct iommu_group *get_pci_device_group(struct pci_dev *pdev)
385 {
386 	struct pci_controller *pci_ctl;
387 	bool pci_endpt_partitioning;
388 	struct iommu_group *group = NULL;
389 
390 	pci_ctl = pci_bus_to_host(pdev->bus);
391 	pci_endpt_partitioning = check_pci_ctl_endpt_part(pci_ctl);
392 	/* We can partition PCIe devices so assign device group to the device */
393 	if (pci_endpt_partitioning) {
394 		group = pci_device_group(&pdev->dev);
395 
396 		/*
397 		 * PCIe controller is not a paritionable entity
398 		 * free the controller device iommu_group.
399 		 */
400 		if (pci_ctl->parent->iommu_group)
401 			iommu_group_remove_device(pci_ctl->parent);
402 	} else {
403 		/*
404 		 * All devices connected to the controller will share the
405 		 * PCI controllers device group. If this is the first
406 		 * device to be probed for the pci controller, copy the
407 		 * device group information from the PCI controller device
408 		 * node and remove the PCI controller iommu group.
409 		 * For subsequent devices, the iommu group information can
410 		 * be obtained from sibling devices (i.e. from the bus_devices
411 		 * link list).
412 		 */
413 		if (pci_ctl->parent->iommu_group) {
414 			group = get_device_iommu_group(pci_ctl->parent);
415 			iommu_group_remove_device(pci_ctl->parent);
416 		} else {
417 			group = get_shared_pci_device_group(pdev);
418 		}
419 	}
420 
421 	if (!group)
422 		group = ERR_PTR(-ENODEV);
423 
424 	return group;
425 }
426 
427 static struct iommu_group *fsl_pamu_device_group(struct device *dev)
428 {
429 	struct iommu_group *group = ERR_PTR(-ENODEV);
430 	int len;
431 
432 	/*
433 	 * For platform devices we allocate a separate group for
434 	 * each of the devices.
435 	 */
436 	if (dev_is_pci(dev))
437 		group = get_pci_device_group(to_pci_dev(dev));
438 	else if (of_get_property(dev->of_node, "fsl,liodn", &len))
439 		group = get_device_iommu_group(dev);
440 
441 	return group;
442 }
443 
444 static struct iommu_device *fsl_pamu_probe_device(struct device *dev)
445 {
446 	return &pamu_iommu;
447 }
448 
449 static void fsl_pamu_release_device(struct device *dev)
450 {
451 }
452 
453 static const struct iommu_ops fsl_pamu_ops = {
454 	.capable	= fsl_pamu_capable,
455 	.domain_alloc	= fsl_pamu_domain_alloc,
456 	.probe_device	= fsl_pamu_probe_device,
457 	.release_device	= fsl_pamu_release_device,
458 	.device_group   = fsl_pamu_device_group,
459 	.default_domain_ops = &(const struct iommu_domain_ops) {
460 		.attach_dev	= fsl_pamu_attach_device,
461 		.detach_dev	= fsl_pamu_detach_device,
462 		.iova_to_phys	= fsl_pamu_iova_to_phys,
463 		.free		= fsl_pamu_domain_free,
464 	}
465 };
466 
467 int __init pamu_domain_init(void)
468 {
469 	int ret = 0;
470 
471 	ret = iommu_init_mempool();
472 	if (ret)
473 		return ret;
474 
475 	ret = iommu_device_sysfs_add(&pamu_iommu, NULL, NULL, "iommu0");
476 	if (ret)
477 		return ret;
478 
479 	ret = iommu_device_register(&pamu_iommu, &fsl_pamu_ops, NULL);
480 	if (ret) {
481 		iommu_device_sysfs_remove(&pamu_iommu);
482 		pr_err("Can't register iommu device\n");
483 		return ret;
484 	}
485 
486 	bus_set_iommu(&platform_bus_type, &fsl_pamu_ops);
487 	bus_set_iommu(&pci_bus_type, &fsl_pamu_ops);
488 
489 	return ret;
490 }
491