xref: /linux/drivers/iommu/fsl_pamu_domain.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
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 <linux/platform_device.h>
13 #include <sysdev/fsl_pci.h>
14 
15 /*
16  * Global spinlock that needs to be held while
17  * configuring PAMU.
18  */
19 static DEFINE_SPINLOCK(iommu_lock);
20 
21 static struct kmem_cache *fsl_pamu_domain_cache;
22 static struct kmem_cache *iommu_devinfo_cache;
23 static DEFINE_SPINLOCK(device_domain_lock);
24 
25 struct iommu_device pamu_iommu;	/* IOMMU core code handle */
26 
27 static struct fsl_dma_domain *to_fsl_dma_domain(struct iommu_domain *dom)
28 {
29 	return container_of(dom, struct fsl_dma_domain, iommu_domain);
30 }
31 
32 static int __init iommu_init_mempool(void)
33 {
34 	fsl_pamu_domain_cache = kmem_cache_create("fsl_pamu_domain",
35 						  sizeof(struct fsl_dma_domain),
36 						  0,
37 						  SLAB_HWCACHE_ALIGN,
38 						  NULL);
39 	if (!fsl_pamu_domain_cache) {
40 		pr_debug("Couldn't create fsl iommu_domain cache\n");
41 		return -ENOMEM;
42 	}
43 
44 	iommu_devinfo_cache = kmem_cache_create("iommu_devinfo",
45 						sizeof(struct device_domain_info),
46 						0,
47 						SLAB_HWCACHE_ALIGN,
48 						NULL);
49 	if (!iommu_devinfo_cache) {
50 		pr_debug("Couldn't create devinfo cache\n");
51 		kmem_cache_destroy(fsl_pamu_domain_cache);
52 		return -ENOMEM;
53 	}
54 
55 	return 0;
56 }
57 
58 static int update_liodn_stash(int liodn, struct fsl_dma_domain *dma_domain,
59 			      u32 val)
60 {
61 	int ret = 0;
62 	unsigned long flags;
63 
64 	spin_lock_irqsave(&iommu_lock, flags);
65 	ret = pamu_update_paace_stash(liodn, val);
66 	if (ret) {
67 		pr_debug("Failed to update SPAACE for liodn %d\n ", liodn);
68 		spin_unlock_irqrestore(&iommu_lock, flags);
69 		return ret;
70 	}
71 
72 	spin_unlock_irqrestore(&iommu_lock, flags);
73 
74 	return ret;
75 }
76 
77 /* Set the geometry parameters for a LIODN */
78 static int pamu_set_liodn(struct fsl_dma_domain *dma_domain, struct device *dev,
79 			  int liodn)
80 {
81 	u32 omi_index = ~(u32)0;
82 	unsigned long flags;
83 	int ret;
84 
85 	/*
86 	 * Configure the omi_index at the geometry setup time.
87 	 * This is a static value which depends on the type of
88 	 * device and would not change thereafter.
89 	 */
90 	get_ome_index(&omi_index, dev);
91 
92 	spin_lock_irqsave(&iommu_lock, flags);
93 	ret = pamu_disable_liodn(liodn);
94 	if (ret)
95 		goto out_unlock;
96 	ret = pamu_config_ppaace(liodn, omi_index, dma_domain->stash_id, 0);
97 	if (ret)
98 		goto out_unlock;
99 	ret = pamu_config_ppaace(liodn, ~(u32)0, dma_domain->stash_id,
100 				 PAACE_AP_PERMS_QUERY | PAACE_AP_PERMS_UPDATE);
101 out_unlock:
102 	spin_unlock_irqrestore(&iommu_lock, flags);
103 	if (ret) {
104 		pr_debug("PAACE configuration failed for liodn %d\n",
105 			 liodn);
106 	}
107 	return ret;
108 }
109 
110 static void remove_device_ref(struct device_domain_info *info)
111 {
112 	unsigned long flags;
113 
114 	list_del(&info->link);
115 	spin_lock_irqsave(&iommu_lock, flags);
116 	pamu_disable_liodn(info->liodn);
117 	spin_unlock_irqrestore(&iommu_lock, flags);
118 	spin_lock_irqsave(&device_domain_lock, flags);
119 	dev_iommu_priv_set(info->dev, NULL);
120 	kmem_cache_free(iommu_devinfo_cache, info);
121 	spin_unlock_irqrestore(&device_domain_lock, flags);
122 }
123 
124 static void detach_device(struct device *dev, struct fsl_dma_domain *dma_domain)
125 {
126 	struct device_domain_info *info, *tmp;
127 	unsigned long flags;
128 
129 	spin_lock_irqsave(&dma_domain->domain_lock, flags);
130 	/* Remove the device from the domain device list */
131 	list_for_each_entry_safe(info, tmp, &dma_domain->devices, link) {
132 		if (!dev || (info->dev == dev))
133 			remove_device_ref(info);
134 	}
135 	spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
136 }
137 
138 static void attach_device(struct fsl_dma_domain *dma_domain, int liodn, struct device *dev)
139 {
140 	struct device_domain_info *info, *old_domain_info;
141 	unsigned long flags;
142 
143 	spin_lock_irqsave(&device_domain_lock, flags);
144 	/*
145 	 * Check here if the device is already attached to domain or not.
146 	 * If the device is already attached to a domain detach it.
147 	 */
148 	old_domain_info = dev_iommu_priv_get(dev);
149 	if (old_domain_info && old_domain_info->domain != dma_domain) {
150 		spin_unlock_irqrestore(&device_domain_lock, flags);
151 		detach_device(dev, old_domain_info->domain);
152 		spin_lock_irqsave(&device_domain_lock, flags);
153 	}
154 
155 	info = kmem_cache_zalloc(iommu_devinfo_cache, GFP_ATOMIC);
156 
157 	info->dev = dev;
158 	info->liodn = liodn;
159 	info->domain = dma_domain;
160 
161 	list_add(&info->link, &dma_domain->devices);
162 	/*
163 	 * In case of devices with multiple LIODNs just store
164 	 * the info for the first LIODN as all
165 	 * LIODNs share the same domain
166 	 */
167 	if (!dev_iommu_priv_get(dev))
168 		dev_iommu_priv_set(dev, info);
169 	spin_unlock_irqrestore(&device_domain_lock, flags);
170 }
171 
172 static phys_addr_t fsl_pamu_iova_to_phys(struct iommu_domain *domain,
173 					 dma_addr_t iova)
174 {
175 	if (iova < domain->geometry.aperture_start ||
176 	    iova > domain->geometry.aperture_end)
177 		return 0;
178 	return iova;
179 }
180 
181 static bool fsl_pamu_capable(struct device *dev, enum iommu_cap cap)
182 {
183 	return cap == IOMMU_CAP_CACHE_COHERENCY;
184 }
185 
186 static void fsl_pamu_domain_free(struct iommu_domain *domain)
187 {
188 	struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);
189 
190 	/* remove all the devices from the device list */
191 	detach_device(NULL, dma_domain);
192 	kmem_cache_free(fsl_pamu_domain_cache, dma_domain);
193 }
194 
195 static struct iommu_domain *fsl_pamu_domain_alloc(unsigned type)
196 {
197 	struct fsl_dma_domain *dma_domain;
198 
199 	/*
200 	 * FIXME: This isn't creating an unmanaged domain since the
201 	 * default_domain_ops do not have any map/unmap function it doesn't meet
202 	 * the requirements for __IOMMU_DOMAIN_PAGING. The only purpose seems to
203 	 * allow drivers/soc/fsl/qbman/qman_portal.c to do
204 	 * fsl_pamu_configure_l1_stash()
205 	 */
206 	if (type != IOMMU_DOMAIN_UNMANAGED)
207 		return NULL;
208 
209 	dma_domain = kmem_cache_zalloc(fsl_pamu_domain_cache, GFP_KERNEL);
210 	if (!dma_domain)
211 		return NULL;
212 
213 	dma_domain->stash_id = ~(u32)0;
214 	INIT_LIST_HEAD(&dma_domain->devices);
215 	spin_lock_init(&dma_domain->domain_lock);
216 
217 	/* default geometry 64 GB i.e. maximum system address */
218 	dma_domain->iommu_domain. geometry.aperture_start = 0;
219 	dma_domain->iommu_domain.geometry.aperture_end = (1ULL << 36) - 1;
220 	dma_domain->iommu_domain.geometry.force_aperture = true;
221 
222 	return &dma_domain->iommu_domain;
223 }
224 
225 /* Update stash destination for all LIODNs associated with the domain */
226 static int update_domain_stash(struct fsl_dma_domain *dma_domain, u32 val)
227 {
228 	struct device_domain_info *info;
229 	int ret = 0;
230 
231 	list_for_each_entry(info, &dma_domain->devices, link) {
232 		ret = update_liodn_stash(info->liodn, dma_domain, val);
233 		if (ret)
234 			break;
235 	}
236 
237 	return ret;
238 }
239 
240 static int fsl_pamu_attach_device(struct iommu_domain *domain,
241 				  struct device *dev)
242 {
243 	struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);
244 	unsigned long flags;
245 	int len, ret = 0, i;
246 	const u32 *liodn;
247 	struct pci_dev *pdev = NULL;
248 	struct pci_controller *pci_ctl;
249 
250 	/*
251 	 * Use LIODN of the PCI controller while attaching a
252 	 * PCI device.
253 	 */
254 	if (dev_is_pci(dev)) {
255 		pdev = to_pci_dev(dev);
256 		pci_ctl = pci_bus_to_host(pdev->bus);
257 		/*
258 		 * make dev point to pci controller device
259 		 * so we can get the LIODN programmed by
260 		 * u-boot.
261 		 */
262 		dev = pci_ctl->parent;
263 	}
264 
265 	liodn = of_get_property(dev->of_node, "fsl,liodn", &len);
266 	if (!liodn) {
267 		pr_debug("missing fsl,liodn property at %pOF\n", dev->of_node);
268 		return -ENODEV;
269 	}
270 
271 	spin_lock_irqsave(&dma_domain->domain_lock, flags);
272 	for (i = 0; i < len / sizeof(u32); i++) {
273 		/* Ensure that LIODN value is valid */
274 		if (liodn[i] >= PAACE_NUMBER_ENTRIES) {
275 			pr_debug("Invalid liodn %d, attach device failed for %pOF\n",
276 				 liodn[i], dev->of_node);
277 			ret = -ENODEV;
278 			break;
279 		}
280 
281 		attach_device(dma_domain, liodn[i], dev);
282 		ret = pamu_set_liodn(dma_domain, dev, liodn[i]);
283 		if (ret)
284 			break;
285 		ret = pamu_enable_liodn(liodn[i]);
286 		if (ret)
287 			break;
288 	}
289 	spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
290 	return ret;
291 }
292 
293 /*
294  * FIXME: fsl/pamu is completely broken in terms of how it works with the iommu
295  * API. Immediately after probe the HW is left in an IDENTITY translation and
296  * the driver provides a non-working UNMANAGED domain that it can switch over
297  * to. However it cannot switch back to an IDENTITY translation, instead it
298  * switches to what looks like BLOCKING.
299  */
300 static int fsl_pamu_platform_attach(struct iommu_domain *platform_domain,
301 				    struct device *dev)
302 {
303 	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
304 	struct fsl_dma_domain *dma_domain;
305 	const u32 *prop;
306 	int len;
307 	struct pci_dev *pdev = NULL;
308 	struct pci_controller *pci_ctl;
309 
310 	/*
311 	 * Hack to keep things working as they always have, only leaving an
312 	 * UNMANAGED domain makes it BLOCKING.
313 	 */
314 	if (domain == platform_domain || !domain ||
315 	    domain->type != IOMMU_DOMAIN_UNMANAGED)
316 		return 0;
317 
318 	dma_domain = to_fsl_dma_domain(domain);
319 
320 	/*
321 	 * Use LIODN of the PCI controller while detaching a
322 	 * PCI device.
323 	 */
324 	if (dev_is_pci(dev)) {
325 		pdev = to_pci_dev(dev);
326 		pci_ctl = pci_bus_to_host(pdev->bus);
327 		/*
328 		 * make dev point to pci controller device
329 		 * so we can get the LIODN programmed by
330 		 * u-boot.
331 		 */
332 		dev = pci_ctl->parent;
333 	}
334 
335 	prop = of_get_property(dev->of_node, "fsl,liodn", &len);
336 	if (prop)
337 		detach_device(dev, dma_domain);
338 	else
339 		pr_debug("missing fsl,liodn property at %pOF\n", dev->of_node);
340 	return 0;
341 }
342 
343 static struct iommu_domain_ops fsl_pamu_platform_ops = {
344 	.attach_dev = fsl_pamu_platform_attach,
345 };
346 
347 static struct iommu_domain fsl_pamu_platform_domain = {
348 	.type = IOMMU_DOMAIN_PLATFORM,
349 	.ops = &fsl_pamu_platform_ops,
350 };
351 
352 /* Set the domain stash attribute */
353 int fsl_pamu_configure_l1_stash(struct iommu_domain *domain, u32 cpu)
354 {
355 	struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);
356 	unsigned long flags;
357 	int ret;
358 
359 	spin_lock_irqsave(&dma_domain->domain_lock, flags);
360 	dma_domain->stash_id = get_stash_id(PAMU_ATTR_CACHE_L1, cpu);
361 	if (dma_domain->stash_id == ~(u32)0) {
362 		pr_debug("Invalid stash attributes\n");
363 		spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
364 		return -EINVAL;
365 	}
366 	ret = update_domain_stash(dma_domain, dma_domain->stash_id);
367 	spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
368 
369 	return ret;
370 }
371 
372 static  bool check_pci_ctl_endpt_part(struct pci_controller *pci_ctl)
373 {
374 	u32 version;
375 
376 	/* Check the PCI controller version number by readding BRR1 register */
377 	version = in_be32(pci_ctl->cfg_addr + (PCI_FSL_BRR1 >> 2));
378 	version &= PCI_FSL_BRR1_VER;
379 	/* If PCI controller version is >= 0x204 we can partition endpoints */
380 	return version >= 0x204;
381 }
382 
383 static struct iommu_group *fsl_pamu_device_group(struct device *dev)
384 {
385 	struct iommu_group *group;
386 	struct pci_dev *pdev;
387 
388 	/*
389 	 * For platform devices we allocate a separate group for each of the
390 	 * devices.
391 	 */
392 	if (!dev_is_pci(dev))
393 		return generic_device_group(dev);
394 
395 	/*
396 	 * We can partition PCIe devices so assign device group to the device
397 	 */
398 	pdev = to_pci_dev(dev);
399 	if (check_pci_ctl_endpt_part(pci_bus_to_host(pdev->bus)))
400 		return pci_device_group(&pdev->dev);
401 
402 	/*
403 	 * All devices connected to the controller will share the same device
404 	 * group.
405 	 *
406 	 * Due to ordering between fsl_pamu_init() and fsl_pci_init() it is
407 	 * guaranteed that the pci_ctl->parent platform_device will have the
408 	 * iommu driver bound and will already have a group set. So we just
409 	 * re-use this group as the group for every device in the hose.
410 	 */
411 	group = iommu_group_get(pci_bus_to_host(pdev->bus)->parent);
412 	if (WARN_ON(!group))
413 		return ERR_PTR(-EINVAL);
414 	return group;
415 }
416 
417 static struct iommu_device *fsl_pamu_probe_device(struct device *dev)
418 {
419 	/*
420 	 * uboot must fill the fsl,liodn for platform devices to be supported by
421 	 * the iommu.
422 	 */
423 	if (!dev_is_pci(dev) &&
424 	    !of_property_present(dev->of_node, "fsl,liodn"))
425 		return ERR_PTR(-ENODEV);
426 
427 	return &pamu_iommu;
428 }
429 
430 static const struct iommu_ops fsl_pamu_ops = {
431 	.default_domain = &fsl_pamu_platform_domain,
432 	.capable	= fsl_pamu_capable,
433 	.domain_alloc	= fsl_pamu_domain_alloc,
434 	.probe_device	= fsl_pamu_probe_device,
435 	.device_group   = fsl_pamu_device_group,
436 	.default_domain_ops = &(const struct iommu_domain_ops) {
437 		.attach_dev	= fsl_pamu_attach_device,
438 		.iova_to_phys	= fsl_pamu_iova_to_phys,
439 		.free		= fsl_pamu_domain_free,
440 	}
441 };
442 
443 int __init pamu_domain_init(void)
444 {
445 	int ret = 0;
446 
447 	ret = iommu_init_mempool();
448 	if (ret)
449 		return ret;
450 
451 	ret = iommu_device_sysfs_add(&pamu_iommu, NULL, NULL, "iommu0");
452 	if (ret)
453 		return ret;
454 
455 	ret = iommu_device_register(&pamu_iommu, &fsl_pamu_ops, NULL);
456 	if (ret) {
457 		iommu_device_sysfs_remove(&pamu_iommu);
458 		pr_err("Can't register iommu device\n");
459 	}
460 
461 	return ret;
462 }
463