summaryrefslogtreecommitdiffstats
path: root/drivers/dma/idxd/cdev.c
blob: 674bfefca088db7a8908866a44615343611e20be (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2019 Intel Corporation. All rights rsvd. */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/device.h>
#include <linux/sched/task.h>
#include <linux/io-64-nonatomic-lo-hi.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/iommu.h>
#include <uapi/linux/idxd.h>
#include "registers.h"
#include "idxd.h"

struct idxd_cdev_context {
	const char *name;
	dev_t devt;
	struct ida minor_ida;
};

/*
 * ictx is an array based off of accelerator types. enum idxd_type
 * is used as index
 */
static struct idxd_cdev_context ictx[IDXD_TYPE_MAX] = {
	{ .name = "dsa" },
	{ .name = "iax" }
};

struct idxd_user_context {
	struct idxd_wq *wq;
	struct task_struct *task;
	unsigned int pasid;
	unsigned int flags;
	struct iommu_sva *sva;
};

static void idxd_cdev_dev_release(struct device *dev)
{
	struct idxd_cdev *idxd_cdev = dev_to_cdev(dev);
	struct idxd_cdev_context *cdev_ctx;
	struct idxd_wq *wq = idxd_cdev->wq;

	cdev_ctx = &ictx[wq->idxd->data->type];
	ida_simple_remove(&cdev_ctx->minor_ida, idxd_cdev->minor);
	kfree(idxd_cdev);
}

static struct device_type idxd_cdev_device_type = {
	.name = "idxd_cdev",
	.release = idxd_cdev_dev_release,
};

static inline struct idxd_cdev *inode_idxd_cdev(struct inode *inode)
{
	struct cdev *cdev = inode->i_cdev;

	return container_of(cdev, struct idxd_cdev, cdev);
}

static inline struct idxd_wq *inode_wq(struct inode *inode)
{
	struct idxd_cdev *idxd_cdev = inode_idxd_cdev(inode);

	return idxd_cdev->wq;
}

static int idxd_cdev_open(struct inode *inode, struct file *filp)
{
	struct idxd_user_context *ctx;
	struct idxd_device *idxd;
	struct idxd_wq *wq;
	struct device *dev;
	int rc = 0;
	struct iommu_sva *sva;
	unsigned int pasid;

	wq = inode_wq(inode);
	idxd = wq->idxd;
	dev = &idxd->pdev->dev;

	dev_dbg(dev, "%s called: %d\n", __func__, idxd_wq_refcount(wq));

	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
	if (!ctx)
		return -ENOMEM;

	mutex_lock(&wq->wq_lock);

	if (idxd_wq_refcount(wq) > 0 && wq_dedicated(wq)) {
		rc = -EBUSY;
		goto failed;
	}

	ctx->wq = wq;
	filp->private_data = ctx;

	if (device_user_pasid_enabled(idxd)) {
		sva = iommu_sva_bind_device(dev, current->mm);
		if (IS_ERR(sva)) {
			rc = PTR_ERR(sva);
			dev_err(dev, "pasid allocation failed: %d\n", rc);
			goto failed;
		}

		pasid = iommu_sva_get_pasid(sva);
		if (pasid == IOMMU_PASID_INVALID) {
			iommu_sva_unbind_device(sva);
			rc = -EINVAL;
			goto failed;
		}

		ctx->sva = sva;
		ctx->pasid = pasid;

		if (wq_dedicated(wq)) {
			rc = idxd_wq_set_pasid(wq, pasid);
			if (rc < 0) {
				iommu_sva_unbind_device(sva);
				dev_err(dev, "wq set pasid failed: %d\n", rc);
				goto failed;
			}
		}
	}

	idxd_wq_get(wq);
	mutex_unlock(&wq->wq_lock);
	return 0;

 failed:
	mutex_unlock(&wq->wq_lock);
	kfree(ctx);
	return rc;
}

static int idxd_cdev_release(struct inode *node, struct file *filep)
{
	struct idxd_user_context *ctx = filep->private_data;
	struct idxd_wq *wq = ctx->wq;
	struct idxd_device *idxd = wq->idxd;
	struct device *dev = &idxd->pdev->dev;
	int rc;

	dev_dbg(dev, "%s called\n", __func__);
	filep->private_data = NULL;

	/* Wait for in-flight operations to complete. */
	if (wq_shared(wq)) {
		idxd_device_drain_pasid(idxd, ctx->pasid);
	} else {
		if (device_user_pasid_enabled(idxd)) {
			/* The wq disable in the disable pasid function will drain the wq */
			rc = idxd_wq_disable_pasid(wq);
			if (rc < 0)
				dev_err(dev, "wq disable pasid failed.\n");
		} else {
			idxd_wq_drain(wq);
		}
	}

	if (ctx->sva)
		iommu_sva_unbind_device(ctx->sva);
	kfree(ctx);
	mutex_lock(&wq->wq_lock);
	idxd_wq_put(wq);
	mutex_unlock(&wq->wq_lock);
	return 0;
}

static int check_vma(struct idxd_wq *wq, struct vm_area_struct *vma,
		     const char *func)
{
	struct device *dev = &wq->idxd->pdev->dev;

	if ((vma->vm_end - vma->vm_start) > PAGE_SIZE) {
		dev_info_ratelimited(dev,
				     "%s: %s: mapping too large: %lu\n",
				     current->comm, func,
				     vma->vm_end - vma->vm_start);
		return -EINVAL;
	}

	return 0;
}

static int idxd_cdev_mmap(struct file *filp, struct vm_area_struct *vma)
{
	struct idxd_user_context *ctx = filp->private_data;
	struct idxd_wq *wq = ctx->wq;
	struct idxd_device *idxd = wq->idxd;
	struct pci_dev *pdev = idxd->pdev;
	phys_addr_t base = pci_resource_start(pdev, IDXD_WQ_BAR);
	unsigned long pfn;
	int rc;

	dev_dbg(&pdev->dev, "%s called\n", __func__);
	rc = check_vma(wq, vma, __func__);
	if (rc < 0)
		return rc;

	vm_flags_set(vma, VM_DONTCOPY);
	pfn = (base + idxd_get_wq_portal_full_offset(wq->id,
				IDXD_PORTAL_LIMITED)) >> PAGE_SHIFT;
	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
	vma->vm_private_data = ctx;

	return io_remap_pfn_range(vma, vma->vm_start, pfn, PAGE_SIZE,
			vma->vm_page_prot);
}

static __poll_t idxd_cdev_poll(struct file *filp,
			       struct poll_table_struct *wait)
{
	struct idxd_user_context *ctx = filp->private_data;
	struct idxd_wq *wq = ctx->wq;
	struct idxd_device *idxd = wq->idxd;
	__poll_t out = 0;

	poll_wait(filp, &wq->err_queue, wait);
	spin_lock(&idxd->dev_lock);
	if (idxd->sw_err.valid)
		out = EPOLLIN | EPOLLRDNORM;
	spin_unlock(&idxd->dev_lock);

	return out;
}

static const struct file_operations idxd_cdev_fops = {
	.owner = THIS_MODULE,
	.open = idxd_cdev_open,
	.release = idxd_cdev_release,
	.mmap = idxd_cdev_mmap,
	.poll = idxd_cdev_poll,
};

int idxd_cdev_get_major(struct idxd_device *idxd)
{
	return MAJOR(ictx[idxd->data->type].devt);
}

int idxd_wq_add_cdev(struct idxd_wq *wq)
{
	struct idxd_device *idxd = wq->idxd;
	struct idxd_cdev *idxd_cdev;
	struct cdev *cdev;
	struct device *dev;
	struct idxd_cdev_context *cdev_ctx;
	int rc, minor;

	idxd_cdev = kzalloc(sizeof(*idxd_cdev), GFP_KERNEL);
	if (!idxd_cdev)
		return -ENOMEM;

	idxd_cdev->idxd_dev.type = IDXD_DEV_CDEV;
	idxd_cdev->wq = wq;
	cdev = &idxd_cdev->cdev;
	dev = cdev_dev(idxd_cdev);
	cdev_ctx = &ictx[wq->idxd->data->type];
	minor = ida_simple_get(&cdev_ctx->minor_ida, 0, MINORMASK, GFP_KERNEL);
	if (minor < 0) {
		kfree(idxd_cdev);
		return minor;
	}
	idxd_cdev->minor = minor;

	device_initialize(dev);
	dev->parent = wq_confdev(wq);
	dev->bus = &dsa_bus_type;
	dev->type = &idxd_cdev_device_type;
	dev->devt = MKDEV(MAJOR(cdev_ctx->devt), minor);

	rc = dev_set_name(dev, "%s/wq%u.%u", idxd->data->name_prefix, idxd->id, wq->id);
	if (rc < 0)
		goto err;

	wq->idxd_cdev = idxd_cdev;
	cdev_init(cdev, &idxd_cdev_fops);
	rc = cdev_device_add(cdev, dev);
	if (rc) {
		dev_dbg(&wq->idxd->pdev->dev, "cdev_add failed: %d\n", rc);
		goto err;
	}

	return 0;

 err:
	put_device(dev);
	wq->idxd_cdev = NULL;
	return rc;
}

void idxd_wq_del_cdev(struct idxd_wq *wq)
{
	struct idxd_cdev *idxd_cdev;

	idxd_cdev = wq->idxd_cdev;
	wq->idxd_cdev = NULL;
	cdev_device_del(&idxd_cdev->cdev, cdev_dev(idxd_cdev));
	put_device(cdev_dev(idxd_cdev));
}

static int idxd_user_drv_probe(struct idxd_dev *idxd_dev)
{
	struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);
	struct idxd_device *idxd = wq->idxd;
	int rc;

	if (idxd->state != IDXD_DEV_ENABLED)
		return -ENXIO;

	/*
	 * User type WQ is enabled only when SVA is enabled for two reasons:
	 *   - If no IOMMU or IOMMU Passthrough without SVA, userspace
	 *     can directly access physical address through the WQ.
	 *   - The IDXD cdev driver does not provide any ways to pin
	 *     user pages and translate the address from user VA to IOVA or
	 *     PA without IOMMU SVA. Therefore the application has no way
	 *     to instruct the device to perform DMA function. This makes
	 *     the cdev not usable for normal application usage.
	 */
	if (!device_user_pasid_enabled(idxd)) {
		idxd->cmd_status = IDXD_SCMD_WQ_USER_NO_IOMMU;
		dev_dbg(&idxd->pdev->dev,
			"User type WQ cannot be enabled without SVA.\n");

		return -EOPNOTSUPP;
	}

	mutex_lock(&wq->wq_lock);
	wq->type = IDXD_WQT_USER;
	rc = drv_enable_wq(wq);
	if (rc < 0)
		goto err;

	rc = idxd_wq_add_cdev(wq);
	if (rc < 0) {
		idxd->cmd_status = IDXD_SCMD_CDEV_ERR;
		goto err_cdev;
	}

	idxd->cmd_status = 0;
	mutex_unlock(&wq->wq_lock);
	return 0;

err_cdev:
	drv_disable_wq(wq);
err:
	wq->type = IDXD_WQT_NONE;
	mutex_unlock(&wq->wq_lock);
	return rc;
}

static void idxd_user_drv_remove(struct idxd_dev *idxd_dev)
{
	struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);

	mutex_lock(&wq->wq_lock);
	idxd_wq_del_cdev(wq);
	drv_disable_wq(wq);
	wq->type = IDXD_WQT_NONE;
	mutex_unlock(&wq->wq_lock);
}

static enum idxd_dev_type dev_types[] = {
	IDXD_DEV_WQ,
	IDXD_DEV_NONE,
};

struct idxd_device_driver idxd_user_drv = {
	.probe = idxd_user_drv_probe,
	.remove = idxd_user_drv_remove,
	.name = "user",
	.type = dev_types,
};
EXPORT_SYMBOL_GPL(idxd_user_drv);

int idxd_cdev_register(void)
{
	int rc, i;

	for (i = 0; i < IDXD_TYPE_MAX; i++) {
		ida_init(&ictx[i].minor_ida);
		rc = alloc_chrdev_region(&ictx[i].devt, 0, MINORMASK,
					 ictx[i].name);
		if (rc)
			goto err_free_chrdev_region;
	}

	return 0;

err_free_chrdev_region:
	for (i--; i >= 0; i--)
		unregister_chrdev_region(ictx[i].devt, MINORMASK);

	return rc;
}

void idxd_cdev_remove(void)
{
	int i;

	for (i = 0; i < IDXD_TYPE_MAX; i++) {
		unregister_chrdev_region(ictx[i].devt, MINORMASK);
		ida_destroy(&ictx[i].minor_ida);
	}
}