Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2/* Copyright(c) 2019 Intel Corporation. All rights rsvd. */
3#include <linux/init.h>
4#include <linux/kernel.h>
5#include <linux/module.h>
6#include <linux/pci.h>
7#include <linux/device.h>
8#include <linux/sched/task.h>
9#include <linux/intel-svm.h>
10#include <linux/io-64-nonatomic-lo-hi.h>
11#include <linux/cdev.h>
12#include <linux/fs.h>
13#include <linux/poll.h>
14#include <uapi/linux/idxd.h>
15#include "registers.h"
16#include "idxd.h"
17
18struct idxd_cdev_context {
19 const char *name;
20 dev_t devt;
21 struct ida minor_ida;
22};
23
24/*
25 * ictx is an array based off of accelerator types. enum idxd_type
26 * is used as index
27 */
28static struct idxd_cdev_context ictx[IDXD_TYPE_MAX] = {
29 { .name = "dsa" },
30};
31
32struct idxd_user_context {
33 struct idxd_wq *wq;
34 struct task_struct *task;
35 unsigned int flags;
36};
37
38enum idxd_cdev_cleanup {
39 CDEV_NORMAL = 0,
40 CDEV_FAILED,
41};
42
43static void idxd_cdev_dev_release(struct device *dev)
44{
45 dev_dbg(dev, "releasing cdev device\n");
46 kfree(dev);
47}
48
49static struct device_type idxd_cdev_device_type = {
50 .name = "idxd_cdev",
51 .release = idxd_cdev_dev_release,
52};
53
54static inline struct idxd_cdev *inode_idxd_cdev(struct inode *inode)
55{
56 struct cdev *cdev = inode->i_cdev;
57
58 return container_of(cdev, struct idxd_cdev, cdev);
59}
60
61static inline struct idxd_wq *idxd_cdev_wq(struct idxd_cdev *idxd_cdev)
62{
63 return container_of(idxd_cdev, struct idxd_wq, idxd_cdev);
64}
65
66static inline struct idxd_wq *inode_wq(struct inode *inode)
67{
68 return idxd_cdev_wq(inode_idxd_cdev(inode));
69}
70
71static int idxd_cdev_open(struct inode *inode, struct file *filp)
72{
73 struct idxd_user_context *ctx;
74 struct idxd_device *idxd;
75 struct idxd_wq *wq;
76 struct device *dev;
77 struct idxd_cdev *idxd_cdev;
78
79 wq = inode_wq(inode);
80 idxd = wq->idxd;
81 dev = &idxd->pdev->dev;
82 idxd_cdev = &wq->idxd_cdev;
83
84 dev_dbg(dev, "%s called\n", __func__);
85
86 if (idxd_wq_refcount(wq) > 1 && wq_dedicated(wq))
87 return -EBUSY;
88
89 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
90 if (!ctx)
91 return -ENOMEM;
92
93 ctx->wq = wq;
94 filp->private_data = ctx;
95 idxd_wq_get(wq);
96 return 0;
97}
98
99static int idxd_cdev_release(struct inode *node, struct file *filep)
100{
101 struct idxd_user_context *ctx = filep->private_data;
102 struct idxd_wq *wq = ctx->wq;
103 struct idxd_device *idxd = wq->idxd;
104 struct device *dev = &idxd->pdev->dev;
105
106 dev_dbg(dev, "%s called\n", __func__);
107 filep->private_data = NULL;
108
109 kfree(ctx);
110 idxd_wq_put(wq);
111 return 0;
112}
113
114static int check_vma(struct idxd_wq *wq, struct vm_area_struct *vma,
115 const char *func)
116{
117 struct device *dev = &wq->idxd->pdev->dev;
118
119 if ((vma->vm_end - vma->vm_start) > PAGE_SIZE) {
120 dev_info_ratelimited(dev,
121 "%s: %s: mapping too large: %lu\n",
122 current->comm, func,
123 vma->vm_end - vma->vm_start);
124 return -EINVAL;
125 }
126
127 return 0;
128}
129
130static int idxd_cdev_mmap(struct file *filp, struct vm_area_struct *vma)
131{
132 struct idxd_user_context *ctx = filp->private_data;
133 struct idxd_wq *wq = ctx->wq;
134 struct idxd_device *idxd = wq->idxd;
135 struct pci_dev *pdev = idxd->pdev;
136 phys_addr_t base = pci_resource_start(pdev, IDXD_WQ_BAR);
137 unsigned long pfn;
138 int rc;
139
140 dev_dbg(&pdev->dev, "%s called\n", __func__);
141 rc = check_vma(wq, vma, __func__);
142
143 vma->vm_flags |= VM_DONTCOPY;
144 pfn = (base + idxd_get_wq_portal_full_offset(wq->id,
145 IDXD_PORTAL_LIMITED)) >> PAGE_SHIFT;
146 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
147 vma->vm_private_data = ctx;
148
149 return io_remap_pfn_range(vma, vma->vm_start, pfn, PAGE_SIZE,
150 vma->vm_page_prot);
151}
152
153static __poll_t idxd_cdev_poll(struct file *filp,
154 struct poll_table_struct *wait)
155{
156 struct idxd_user_context *ctx = filp->private_data;
157 struct idxd_wq *wq = ctx->wq;
158 struct idxd_device *idxd = wq->idxd;
159 struct idxd_cdev *idxd_cdev = &wq->idxd_cdev;
160 unsigned long flags;
161 __poll_t out = 0;
162
163 poll_wait(filp, &idxd_cdev->err_queue, wait);
164 spin_lock_irqsave(&idxd->dev_lock, flags);
165 if (idxd->sw_err.valid)
166 out = EPOLLIN | EPOLLRDNORM;
167 spin_unlock_irqrestore(&idxd->dev_lock, flags);
168
169 return out;
170}
171
172static const struct file_operations idxd_cdev_fops = {
173 .owner = THIS_MODULE,
174 .open = idxd_cdev_open,
175 .release = idxd_cdev_release,
176 .mmap = idxd_cdev_mmap,
177 .poll = idxd_cdev_poll,
178};
179
180int idxd_cdev_get_major(struct idxd_device *idxd)
181{
182 return MAJOR(ictx[idxd->type].devt);
183}
184
185static int idxd_wq_cdev_dev_setup(struct idxd_wq *wq)
186{
187 struct idxd_device *idxd = wq->idxd;
188 struct idxd_cdev *idxd_cdev = &wq->idxd_cdev;
189 struct idxd_cdev_context *cdev_ctx;
190 struct device *dev;
191 int minor, rc;
192
193 idxd_cdev->dev = kzalloc(sizeof(*idxd_cdev->dev), GFP_KERNEL);
194 if (!idxd_cdev->dev)
195 return -ENOMEM;
196
197 dev = idxd_cdev->dev;
198 dev->parent = &idxd->pdev->dev;
199 dev_set_name(dev, "%s/wq%u.%u", idxd_get_dev_name(idxd),
200 idxd->id, wq->id);
201 dev->bus = idxd_get_bus_type(idxd);
202
203 cdev_ctx = &ictx[wq->idxd->type];
204 minor = ida_simple_get(&cdev_ctx->minor_ida, 0, MINORMASK, GFP_KERNEL);
205 if (minor < 0) {
206 rc = minor;
207 goto ida_err;
208 }
209
210 dev->devt = MKDEV(MAJOR(cdev_ctx->devt), minor);
211 dev->type = &idxd_cdev_device_type;
212 rc = device_register(dev);
213 if (rc < 0) {
214 dev_err(&idxd->pdev->dev, "device register failed\n");
215 put_device(dev);
216 goto dev_reg_err;
217 }
218 idxd_cdev->minor = minor;
219
220 return 0;
221
222 dev_reg_err:
223 ida_simple_remove(&cdev_ctx->minor_ida, MINOR(dev->devt));
224 ida_err:
225 kfree(dev);
226 idxd_cdev->dev = NULL;
227 return rc;
228}
229
230static void idxd_wq_cdev_cleanup(struct idxd_wq *wq,
231 enum idxd_cdev_cleanup cdev_state)
232{
233 struct idxd_cdev *idxd_cdev = &wq->idxd_cdev;
234 struct idxd_cdev_context *cdev_ctx;
235
236 cdev_ctx = &ictx[wq->idxd->type];
237 if (cdev_state == CDEV_NORMAL)
238 cdev_del(&idxd_cdev->cdev);
239 device_unregister(idxd_cdev->dev);
240 /*
241 * The device_type->release() will be called on the device and free
242 * the allocated struct device. We can just forget it.
243 */
244 ida_simple_remove(&cdev_ctx->minor_ida, idxd_cdev->minor);
245 idxd_cdev->dev = NULL;
246 idxd_cdev->minor = -1;
247}
248
249int idxd_wq_add_cdev(struct idxd_wq *wq)
250{
251 struct idxd_cdev *idxd_cdev = &wq->idxd_cdev;
252 struct cdev *cdev = &idxd_cdev->cdev;
253 struct device *dev;
254 int rc;
255
256 rc = idxd_wq_cdev_dev_setup(wq);
257 if (rc < 0)
258 return rc;
259
260 dev = idxd_cdev->dev;
261 cdev_init(cdev, &idxd_cdev_fops);
262 cdev_set_parent(cdev, &dev->kobj);
263 rc = cdev_add(cdev, dev->devt, 1);
264 if (rc) {
265 dev_dbg(&wq->idxd->pdev->dev, "cdev_add failed: %d\n", rc);
266 idxd_wq_cdev_cleanup(wq, CDEV_FAILED);
267 return rc;
268 }
269
270 init_waitqueue_head(&idxd_cdev->err_queue);
271 return 0;
272}
273
274void idxd_wq_del_cdev(struct idxd_wq *wq)
275{
276 idxd_wq_cdev_cleanup(wq, CDEV_NORMAL);
277}
278
279int idxd_cdev_register(void)
280{
281 int rc, i;
282
283 for (i = 0; i < IDXD_TYPE_MAX; i++) {
284 ida_init(&ictx[i].minor_ida);
285 rc = alloc_chrdev_region(&ictx[i].devt, 0, MINORMASK,
286 ictx[i].name);
287 if (rc)
288 return rc;
289 }
290
291 return 0;
292}
293
294void idxd_cdev_remove(void)
295{
296 int i;
297
298 for (i = 0; i < IDXD_TYPE_MAX; i++) {
299 unregister_chrdev_region(ictx[i].devt, MINORMASK);
300 ida_destroy(&ictx[i].minor_ida);
301 }
302}