summaryrefslogtreecommitdiff
path: root/drivers/cxl/core/memdev.c
blob: a74a93310d26d1fa2cd369248955c50801135531 (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
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright(c) 2020 Intel Corporation. */

#include <linux/device.h>
#include <linux/slab.h>
#include <linux/idr.h>
#include <linux/pci.h>
#include <cxlmem.h>
#include "core.h"

static DECLARE_RWSEM(cxl_memdev_rwsem);

/*
 * An entire PCI topology full of devices should be enough for any
 * config
 */
#define CXL_MEM_MAX_DEVS 65536

static int cxl_mem_major;
static DEFINE_IDA(cxl_memdev_ida);

static void cxl_memdev_release(struct device *dev)
{
	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);

	ida_free(&cxl_memdev_ida, cxlmd->id);
	kfree(cxlmd);
}

static char *cxl_memdev_devnode(struct device *dev, umode_t *mode, kuid_t *uid,
				kgid_t *gid)
{
	return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev));
}

static ssize_t firmware_version_show(struct device *dev,
				     struct device_attribute *attr, char *buf)
{
	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
	struct cxl_dev_state *cxlds = cxlmd->cxlds;

	return sysfs_emit(buf, "%.16s\n", cxlds->firmware_version);
}
static DEVICE_ATTR_RO(firmware_version);

static ssize_t payload_max_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
	struct cxl_dev_state *cxlds = cxlmd->cxlds;

	return sysfs_emit(buf, "%zu\n", cxlds->payload_size);
}
static DEVICE_ATTR_RO(payload_max);

static ssize_t label_storage_size_show(struct device *dev,
				       struct device_attribute *attr, char *buf)
{
	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
	struct cxl_dev_state *cxlds = cxlmd->cxlds;

	return sysfs_emit(buf, "%zu\n", cxlds->lsa_size);
}
static DEVICE_ATTR_RO(label_storage_size);

static ssize_t ram_size_show(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
	struct cxl_dev_state *cxlds = cxlmd->cxlds;
	unsigned long long len = resource_size(&cxlds->ram_res);

	return sysfs_emit(buf, "%#llx\n", len);
}

static struct device_attribute dev_attr_ram_size =
	__ATTR(size, 0444, ram_size_show, NULL);

static ssize_t pmem_size_show(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
	struct cxl_dev_state *cxlds = cxlmd->cxlds;
	unsigned long long len = resource_size(&cxlds->pmem_res);

	return sysfs_emit(buf, "%#llx\n", len);
}

static struct device_attribute dev_attr_pmem_size =
	__ATTR(size, 0444, pmem_size_show, NULL);

static ssize_t serial_show(struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
	struct cxl_dev_state *cxlds = cxlmd->cxlds;

	return sysfs_emit(buf, "%#llx\n", cxlds->serial);
}
static DEVICE_ATTR_RO(serial);

static ssize_t numa_node_show(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	return sprintf(buf, "%d\n", dev_to_node(dev));
}
static DEVICE_ATTR_RO(numa_node);

static struct attribute *cxl_memdev_attributes[] = {
	&dev_attr_serial.attr,
	&dev_attr_firmware_version.attr,
	&dev_attr_payload_max.attr,
	&dev_attr_label_storage_size.attr,
	&dev_attr_numa_node.attr,
	NULL,
};

static struct attribute *cxl_memdev_pmem_attributes[] = {
	&dev_attr_pmem_size.attr,
	NULL,
};

static struct attribute *cxl_memdev_ram_attributes[] = {
	&dev_attr_ram_size.attr,
	NULL,
};

static umode_t cxl_memdev_visible(struct kobject *kobj, struct attribute *a,
				  int n)
{
	if (!IS_ENABLED(CONFIG_NUMA) && a == &dev_attr_numa_node.attr)
		return 0;
	return a->mode;
}

static struct attribute_group cxl_memdev_attribute_group = {
	.attrs = cxl_memdev_attributes,
	.is_visible = cxl_memdev_visible,
};

static struct attribute_group cxl_memdev_ram_attribute_group = {
	.name = "ram",
	.attrs = cxl_memdev_ram_attributes,
};

static struct attribute_group cxl_memdev_pmem_attribute_group = {
	.name = "pmem",
	.attrs = cxl_memdev_pmem_attributes,
};

static const struct attribute_group *cxl_memdev_attribute_groups[] = {
	&cxl_memdev_attribute_group,
	&cxl_memdev_ram_attribute_group,
	&cxl_memdev_pmem_attribute_group,
	NULL,
};

static const struct device_type cxl_memdev_type = {
	.name = "cxl_memdev",
	.release = cxl_memdev_release,
	.devnode = cxl_memdev_devnode,
	.groups = cxl_memdev_attribute_groups,
};

bool is_cxl_memdev(struct device *dev)
{
	return dev->type == &cxl_memdev_type;
}
EXPORT_SYMBOL_NS_GPL(is_cxl_memdev, CXL);

/**
 * set_exclusive_cxl_commands() - atomically disable user cxl commands
 * @cxlds: The device state to operate on
 * @cmds: bitmap of commands to mark exclusive
 *
 * Grab the cxl_memdev_rwsem in write mode to flush in-flight
 * invocations of the ioctl path and then disable future execution of
 * commands with the command ids set in @cmds.
 */
void set_exclusive_cxl_commands(struct cxl_dev_state *cxlds, unsigned long *cmds)
{
	down_write(&cxl_memdev_rwsem);
	bitmap_or(cxlds->exclusive_cmds, cxlds->exclusive_cmds, cmds,
		  CXL_MEM_COMMAND_ID_MAX);
	up_write(&cxl_memdev_rwsem);
}
EXPORT_SYMBOL_NS_GPL(set_exclusive_cxl_commands, CXL);

/**
 * clear_exclusive_cxl_commands() - atomically enable user cxl commands
 * @cxlds: The device state to modify
 * @cmds: bitmap of commands to mark available for userspace
 */
void clear_exclusive_cxl_commands(struct cxl_dev_state *cxlds, unsigned long *cmds)
{
	down_write(&cxl_memdev_rwsem);
	bitmap_andnot(cxlds->exclusive_cmds, cxlds->exclusive_cmds, cmds,
		      CXL_MEM_COMMAND_ID_MAX);
	up_write(&cxl_memdev_rwsem);
}
EXPORT_SYMBOL_NS_GPL(clear_exclusive_cxl_commands, CXL);

static void cxl_memdev_shutdown(struct device *dev)
{
	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);

	down_write(&cxl_memdev_rwsem);
	cxlmd->cxlds = NULL;
	up_write(&cxl_memdev_rwsem);
}

static void cxl_memdev_unregister(void *_cxlmd)
{
	struct cxl_memdev *cxlmd = _cxlmd;
	struct device *dev = &cxlmd->dev;

	cxl_memdev_shutdown(dev);
	cdev_device_del(&cxlmd->cdev, dev);
	put_device(dev);
}

static void detach_memdev(struct work_struct *work)
{
	struct cxl_memdev *cxlmd;

	cxlmd = container_of(work, typeof(*cxlmd), detach_work);
	device_release_driver(&cxlmd->dev);
	put_device(&cxlmd->dev);
}

static struct lock_class_key cxl_memdev_key;

static struct cxl_memdev *cxl_memdev_alloc(struct cxl_dev_state *cxlds,
					   const struct file_operations *fops)
{
	struct cxl_memdev *cxlmd;
	struct device *dev;
	struct cdev *cdev;
	int rc;

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

	rc = ida_alloc_range(&cxl_memdev_ida, 0, CXL_MEM_MAX_DEVS, GFP_KERNEL);
	if (rc < 0)
		goto err;
	cxlmd->id = rc;

	dev = &cxlmd->dev;
	device_initialize(dev);
	lockdep_set_class(&dev->mutex, &cxl_memdev_key);
	dev->parent = cxlds->dev;
	dev->bus = &cxl_bus_type;
	dev->devt = MKDEV(cxl_mem_major, cxlmd->id);
	dev->type = &cxl_memdev_type;
	device_set_pm_not_required(dev);
	INIT_WORK(&cxlmd->detach_work, detach_memdev);

	cdev = &cxlmd->cdev;
	cdev_init(cdev, fops);
	return cxlmd;

err:
	kfree(cxlmd);
	return ERR_PTR(rc);
}

static long __cxl_memdev_ioctl(struct cxl_memdev *cxlmd, unsigned int cmd,
			       unsigned long arg)
{
	switch (cmd) {
	case CXL_MEM_QUERY_COMMANDS:
		return cxl_query_cmd(cxlmd, (void __user *)arg);
	case CXL_MEM_SEND_COMMAND:
		return cxl_send_cmd(cxlmd, (void __user *)arg);
	default:
		return -ENOTTY;
	}
}

static long cxl_memdev_ioctl(struct file *file, unsigned int cmd,
			     unsigned long arg)
{
	struct cxl_memdev *cxlmd = file->private_data;
	int rc = -ENXIO;

	down_read(&cxl_memdev_rwsem);
	if (cxlmd->cxlds)
		rc = __cxl_memdev_ioctl(cxlmd, cmd, arg);
	up_read(&cxl_memdev_rwsem);

	return rc;
}

static int cxl_memdev_open(struct inode *inode, struct file *file)
{
	struct cxl_memdev *cxlmd =
		container_of(inode->i_cdev, typeof(*cxlmd), cdev);

	get_device(&cxlmd->dev);
	file->private_data = cxlmd;

	return 0;
}

static int cxl_memdev_release_file(struct inode *inode, struct file *file)
{
	struct cxl_memdev *cxlmd =
		container_of(inode->i_cdev, typeof(*cxlmd), cdev);

	put_device(&cxlmd->dev);

	return 0;
}

static const struct file_operations cxl_memdev_fops = {
	.owner = THIS_MODULE,
	.unlocked_ioctl = cxl_memdev_ioctl,
	.open = cxl_memdev_open,
	.release = cxl_memdev_release_file,
	.compat_ioctl = compat_ptr_ioctl,
	.llseek = noop_llseek,
};

struct cxl_memdev *devm_cxl_add_memdev(struct cxl_dev_state *cxlds)
{
	struct cxl_memdev *cxlmd;
	struct device *dev;
	struct cdev *cdev;
	int rc;

	cxlmd = cxl_memdev_alloc(cxlds, &cxl_memdev_fops);
	if (IS_ERR(cxlmd))
		return cxlmd;

	dev = &cxlmd->dev;
	rc = dev_set_name(dev, "mem%d", cxlmd->id);
	if (rc)
		goto err;

	/*
	 * Activate ioctl operations, no cxl_memdev_rwsem manipulation
	 * needed as this is ordered with cdev_add() publishing the device.
	 */
	cxlmd->cxlds = cxlds;
	cxlds->cxlmd = cxlmd;

	cdev = &cxlmd->cdev;
	rc = cdev_device_add(cdev, dev);
	if (rc)
		goto err;

	rc = devm_add_action_or_reset(cxlds->dev, cxl_memdev_unregister, cxlmd);
	if (rc)
		return ERR_PTR(rc);
	return cxlmd;

err:
	/*
	 * The cdev was briefly live, shutdown any ioctl operations that
	 * saw that state.
	 */
	cxl_memdev_shutdown(dev);
	put_device(dev);
	return ERR_PTR(rc);
}
EXPORT_SYMBOL_NS_GPL(devm_cxl_add_memdev, CXL);

__init int cxl_memdev_init(void)
{
	dev_t devt;
	int rc;

	rc = alloc_chrdev_region(&devt, 0, CXL_MEM_MAX_DEVS, "cxl");
	if (rc)
		return rc;

	cxl_mem_major = MAJOR(devt);

	return 0;
}

void cxl_memdev_exit(void)
{
	unregister_chrdev_region(MKDEV(cxl_mem_major, 0), CXL_MEM_MAX_DEVS);
}