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8
9#define pr_fmt(fmt) "opal-prd: " fmt
10
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/platform_device.h>
14#include <linux/miscdevice.h>
15#include <linux/fs.h>
16#include <linux/of.h>
17#include <linux/of_address.h>
18#include <linux/poll.h>
19#include <linux/mm.h>
20#include <linux/slab.h>
21#include <asm/opal-prd.h>
22#include <asm/opal.h>
23#include <asm/io.h>
24#include <linux/uaccess.h>
25
26
27
28
29
30
31struct opal_prd_msg_queue_item {
32 struct list_head list;
33 struct opal_prd_msg_header msg;
34};
35
36static struct device_node *prd_node;
37static LIST_HEAD(opal_prd_msg_queue);
38static DEFINE_SPINLOCK(opal_prd_msg_queue_lock);
39static DECLARE_WAIT_QUEUE_HEAD(opal_prd_msg_wait);
40static atomic_t prd_usage;
41
42static bool opal_prd_range_is_valid(uint64_t addr, uint64_t size)
43{
44 struct device_node *parent, *node;
45 bool found;
46
47 if (addr + size < addr)
48 return false;
49
50 parent = of_find_node_by_path("/reserved-memory");
51 if (!parent)
52 return false;
53
54 found = false;
55
56 for_each_child_of_node(parent, node) {
57 uint64_t range_addr, range_size, range_end;
58 const __be32 *addrp;
59 const char *label;
60
61 addrp = of_get_address(node, 0, &range_size, NULL);
62
63 range_addr = of_read_number(addrp, 2);
64 range_end = range_addr + range_size;
65
66 label = of_get_property(node, "ibm,prd-label", NULL);
67
68
69 if (!label)
70 continue;
71
72 if (range_end <= range_addr)
73 continue;
74
75 if (addr >= range_addr && addr + size <= range_end) {
76 found = true;
77 of_node_put(node);
78 break;
79 }
80 }
81
82 of_node_put(parent);
83 return found;
84}
85
86static int opal_prd_open(struct inode *inode, struct file *file)
87{
88
89
90
91
92 if (atomic_xchg(&prd_usage, 1) == 1)
93 return -EBUSY;
94
95 return 0;
96}
97
98
99
100
101
102
103
104static int opal_prd_mmap(struct file *file, struct vm_area_struct *vma)
105{
106 size_t addr, size;
107 pgprot_t page_prot;
108
109 pr_devel("opal_prd_mmap(0x%016lx, 0x%016lx, 0x%lx, 0x%lx)\n",
110 vma->vm_start, vma->vm_end, vma->vm_pgoff,
111 vma->vm_flags);
112
113 addr = vma->vm_pgoff << PAGE_SHIFT;
114 size = vma->vm_end - vma->vm_start;
115
116
117 if (!opal_prd_range_is_valid(addr, size))
118 return -EINVAL;
119
120 page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
121 size, vma->vm_page_prot);
122
123 return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, size,
124 page_prot);
125}
126
127static bool opal_msg_queue_empty(void)
128{
129 unsigned long flags;
130 bool ret;
131
132 spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
133 ret = list_empty(&opal_prd_msg_queue);
134 spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);
135
136 return ret;
137}
138
139static __poll_t opal_prd_poll(struct file *file,
140 struct poll_table_struct *wait)
141{
142 poll_wait(file, &opal_prd_msg_wait, wait);
143
144 if (!opal_msg_queue_empty())
145 return EPOLLIN | EPOLLRDNORM;
146
147 return 0;
148}
149
150static ssize_t opal_prd_read(struct file *file, char __user *buf,
151 size_t count, loff_t *ppos)
152{
153 struct opal_prd_msg_queue_item *item;
154 unsigned long flags;
155 ssize_t size, err;
156 int rc;
157
158
159 if (count < sizeof(item->msg))
160 return -EINVAL;
161
162 if (*ppos)
163 return -ESPIPE;
164
165 item = NULL;
166
167 for (;;) {
168
169 spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
170 if (!list_empty(&opal_prd_msg_queue)) {
171 item = list_first_entry(&opal_prd_msg_queue,
172 struct opal_prd_msg_queue_item, list);
173 list_del(&item->list);
174 }
175 spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);
176
177 if (item)
178 break;
179
180 if (file->f_flags & O_NONBLOCK)
181 return -EAGAIN;
182
183 rc = wait_event_interruptible(opal_prd_msg_wait,
184 !opal_msg_queue_empty());
185 if (rc)
186 return -EINTR;
187 }
188
189 size = be16_to_cpu(item->msg.size);
190 if (size > count) {
191 err = -EINVAL;
192 goto err_requeue;
193 }
194
195 rc = copy_to_user(buf, &item->msg, size);
196 if (rc) {
197 err = -EFAULT;
198 goto err_requeue;
199 }
200
201 kfree(item);
202
203 return size;
204
205err_requeue:
206
207 spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
208 list_add(&item->list, &opal_prd_msg_queue);
209 spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);
210 return err;
211}
212
213static ssize_t opal_prd_write(struct file *file, const char __user *buf,
214 size_t count, loff_t *ppos)
215{
216 struct opal_prd_msg_header hdr;
217 ssize_t size;
218 void *msg;
219 int rc;
220
221 size = sizeof(hdr);
222
223 if (count < size)
224 return -EINVAL;
225
226
227 rc = copy_from_user(&hdr, buf, sizeof(hdr));
228 if (rc)
229 return -EFAULT;
230
231 size = be16_to_cpu(hdr.size);
232
233 msg = memdup_user(buf, size);
234 if (IS_ERR(msg))
235 return PTR_ERR(msg);
236
237 rc = opal_prd_msg(msg);
238 if (rc) {
239 pr_warn("write: opal_prd_msg returned %d\n", rc);
240 size = -EIO;
241 }
242
243 kfree(msg);
244
245 return size;
246}
247
248static int opal_prd_release(struct inode *inode, struct file *file)
249{
250 struct opal_prd_msg_header msg;
251
252 msg.size = cpu_to_be16(sizeof(msg));
253 msg.type = OPAL_PRD_MSG_TYPE_FINI;
254
255 opal_prd_msg((struct opal_prd_msg *)&msg);
256
257 atomic_xchg(&prd_usage, 0);
258
259 return 0;
260}
261
262static long opal_prd_ioctl(struct file *file, unsigned int cmd,
263 unsigned long param)
264{
265 struct opal_prd_info info;
266 struct opal_prd_scom scom;
267 int rc = 0;
268
269 switch (cmd) {
270 case OPAL_PRD_GET_INFO:
271 memset(&info, 0, sizeof(info));
272 info.version = OPAL_PRD_KERNEL_VERSION;
273 rc = copy_to_user((void __user *)param, &info, sizeof(info));
274 if (rc)
275 return -EFAULT;
276 break;
277
278 case OPAL_PRD_SCOM_READ:
279 rc = copy_from_user(&scom, (void __user *)param, sizeof(scom));
280 if (rc)
281 return -EFAULT;
282
283 scom.rc = opal_xscom_read(scom.chip, scom.addr,
284 (__be64 *)&scom.data);
285 scom.data = be64_to_cpu(scom.data);
286 pr_devel("ioctl SCOM_READ: chip %llx addr %016llx data %016llx rc %lld\n",
287 scom.chip, scom.addr, scom.data, scom.rc);
288
289 rc = copy_to_user((void __user *)param, &scom, sizeof(scom));
290 if (rc)
291 return -EFAULT;
292 break;
293
294 case OPAL_PRD_SCOM_WRITE:
295 rc = copy_from_user(&scom, (void __user *)param, sizeof(scom));
296 if (rc)
297 return -EFAULT;
298
299 scom.rc = opal_xscom_write(scom.chip, scom.addr, scom.data);
300 pr_devel("ioctl SCOM_WRITE: chip %llx addr %016llx data %016llx rc %lld\n",
301 scom.chip, scom.addr, scom.data, scom.rc);
302
303 rc = copy_to_user((void __user *)param, &scom, sizeof(scom));
304 if (rc)
305 return -EFAULT;
306 break;
307
308 default:
309 rc = -EINVAL;
310 }
311
312 return rc;
313}
314
315static const struct file_operations opal_prd_fops = {
316 .open = opal_prd_open,
317 .mmap = opal_prd_mmap,
318 .poll = opal_prd_poll,
319 .read = opal_prd_read,
320 .write = opal_prd_write,
321 .unlocked_ioctl = opal_prd_ioctl,
322 .release = opal_prd_release,
323 .owner = THIS_MODULE,
324};
325
326static struct miscdevice opal_prd_dev = {
327 .minor = MISC_DYNAMIC_MINOR,
328 .name = "opal-prd",
329 .fops = &opal_prd_fops,
330};
331
332
333static int opal_prd_msg_notifier(struct notifier_block *nb,
334 unsigned long msg_type, void *_msg)
335{
336 struct opal_prd_msg_queue_item *item;
337 struct opal_prd_msg_header *hdr;
338 struct opal_msg *msg = _msg;
339 int msg_size, item_size;
340 unsigned long flags;
341
342 if (msg_type != OPAL_MSG_PRD && msg_type != OPAL_MSG_PRD2)
343 return 0;
344
345
346
347 hdr = (void *)msg->params;
348 msg_size = be16_to_cpu(hdr->size);
349 item_size = msg_size + sizeof(*item) - sizeof(item->msg);
350
351 item = kzalloc(item_size, GFP_ATOMIC);
352 if (!item)
353 return -ENOMEM;
354
355 memcpy(&item->msg, msg->params, msg_size);
356
357 spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
358 list_add_tail(&item->list, &opal_prd_msg_queue);
359 spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);
360
361 wake_up_interruptible(&opal_prd_msg_wait);
362
363 return 0;
364}
365
366static struct notifier_block opal_prd_event_nb = {
367 .notifier_call = opal_prd_msg_notifier,
368 .next = NULL,
369 .priority = 0,
370};
371
372static int opal_prd_probe(struct platform_device *pdev)
373{
374 int rc;
375
376 if (!pdev || !pdev->dev.of_node)
377 return -ENODEV;
378
379
380
381
382 if (prd_node)
383 return -EBUSY;
384
385 prd_node = pdev->dev.of_node;
386
387 rc = opal_message_notifier_register(OPAL_MSG_PRD, &opal_prd_event_nb);
388 if (rc) {
389 pr_err("Couldn't register event notifier\n");
390 return rc;
391 }
392
393 rc = opal_message_notifier_register(OPAL_MSG_PRD2, &opal_prd_event_nb);
394 if (rc) {
395 pr_err("Couldn't register PRD2 event notifier\n");
396 return rc;
397 }
398
399 rc = misc_register(&opal_prd_dev);
400 if (rc) {
401 pr_err("failed to register miscdev\n");
402 opal_message_notifier_unregister(OPAL_MSG_PRD,
403 &opal_prd_event_nb);
404 return rc;
405 }
406
407 return 0;
408}
409
410static int opal_prd_remove(struct platform_device *pdev)
411{
412 misc_deregister(&opal_prd_dev);
413 opal_message_notifier_unregister(OPAL_MSG_PRD, &opal_prd_event_nb);
414 return 0;
415}
416
417static const struct of_device_id opal_prd_match[] = {
418 { .compatible = "ibm,opal-prd" },
419 { },
420};
421
422static struct platform_driver opal_prd_driver = {
423 .driver = {
424 .name = "opal-prd",
425 .of_match_table = opal_prd_match,
426 },
427 .probe = opal_prd_probe,
428 .remove = opal_prd_remove,
429};
430
431module_platform_driver(opal_prd_driver);
432
433MODULE_DEVICE_TABLE(of, opal_prd_match);
434MODULE_DESCRIPTION("PowerNV OPAL runtime diagnostic driver");
435MODULE_LICENSE("GPL");
436
