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17#define pr_fmt(fmt) "opal-prd: " fmt
18
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/platform_device.h>
22#include <linux/miscdevice.h>
23#include <linux/fs.h>
24#include <linux/of.h>
25#include <linux/of_address.h>
26#include <linux/poll.h>
27#include <linux/mm.h>
28#include <linux/slab.h>
29#include <asm/opal-prd.h>
30#include <asm/opal.h>
31#include <asm/io.h>
32#include <asm/uaccess.h>
33
34
35
36
37
38
39struct opal_prd_msg_queue_item {
40 struct list_head list;
41 struct opal_prd_msg_header msg;
42};
43
44static struct device_node *prd_node;
45static LIST_HEAD(opal_prd_msg_queue);
46static DEFINE_SPINLOCK(opal_prd_msg_queue_lock);
47static DECLARE_WAIT_QUEUE_HEAD(opal_prd_msg_wait);
48static atomic_t prd_usage;
49
50static bool opal_prd_range_is_valid(uint64_t addr, uint64_t size)
51{
52 struct device_node *parent, *node;
53 bool found;
54
55 if (addr + size < addr)
56 return false;
57
58 parent = of_find_node_by_path("/reserved-memory");
59 if (!parent)
60 return false;
61
62 found = false;
63
64 for_each_child_of_node(parent, node) {
65 uint64_t range_addr, range_size, range_end;
66 const __be32 *addrp;
67 const char *label;
68
69 addrp = of_get_address(node, 0, &range_size, NULL);
70
71 range_addr = of_read_number(addrp, 2);
72 range_end = range_addr + range_size;
73
74 label = of_get_property(node, "ibm,prd-label", NULL);
75
76
77 if (!label)
78 continue;
79
80 if (range_end <= range_addr)
81 continue;
82
83 if (addr >= range_addr && addr + size <= range_end) {
84 found = true;
85 of_node_put(node);
86 break;
87 }
88 }
89
90 of_node_put(parent);
91 return found;
92}
93
94static int opal_prd_open(struct inode *inode, struct file *file)
95{
96
97
98
99
100 if (atomic_xchg(&prd_usage, 1) == 1)
101 return -EBUSY;
102
103 return 0;
104}
105
106
107
108
109
110
111
112static int opal_prd_mmap(struct file *file, struct vm_area_struct *vma)
113{
114 size_t addr, size;
115 pgprot_t page_prot;
116 int rc;
117
118 pr_devel("opal_prd_mmap(0x%016lx, 0x%016lx, 0x%lx, 0x%lx)\n",
119 vma->vm_start, vma->vm_end, vma->vm_pgoff,
120 vma->vm_flags);
121
122 addr = vma->vm_pgoff << PAGE_SHIFT;
123 size = vma->vm_end - vma->vm_start;
124
125
126 if (!opal_prd_range_is_valid(addr, size))
127 return -EINVAL;
128
129 page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
130 size, vma->vm_page_prot);
131
132 rc = remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, size,
133 page_prot);
134
135 return rc;
136}
137
138static bool opal_msg_queue_empty(void)
139{
140 unsigned long flags;
141 bool ret;
142
143 spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
144 ret = list_empty(&opal_prd_msg_queue);
145 spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);
146
147 return ret;
148}
149
150static unsigned int opal_prd_poll(struct file *file,
151 struct poll_table_struct *wait)
152{
153 poll_wait(file, &opal_prd_msg_wait, wait);
154
155 if (!opal_msg_queue_empty())
156 return POLLIN | POLLRDNORM;
157
158 return 0;
159}
160
161static ssize_t opal_prd_read(struct file *file, char __user *buf,
162 size_t count, loff_t *ppos)
163{
164 struct opal_prd_msg_queue_item *item;
165 unsigned long flags;
166 ssize_t size, err;
167 int rc;
168
169
170 if (count < sizeof(item->msg))
171 return -EINVAL;
172
173 if (*ppos)
174 return -ESPIPE;
175
176 item = NULL;
177
178 for (;;) {
179
180 spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
181 if (!list_empty(&opal_prd_msg_queue)) {
182 item = list_first_entry(&opal_prd_msg_queue,
183 struct opal_prd_msg_queue_item, list);
184 list_del(&item->list);
185 }
186 spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);
187
188 if (item)
189 break;
190
191 if (file->f_flags & O_NONBLOCK)
192 return -EAGAIN;
193
194 rc = wait_event_interruptible(opal_prd_msg_wait,
195 !opal_msg_queue_empty());
196 if (rc)
197 return -EINTR;
198 }
199
200 size = be16_to_cpu(item->msg.size);
201 if (size > count) {
202 err = -EINVAL;
203 goto err_requeue;
204 }
205
206 rc = copy_to_user(buf, &item->msg, size);
207 if (rc) {
208 err = -EFAULT;
209 goto err_requeue;
210 }
211
212 kfree(item);
213
214 return size;
215
216err_requeue:
217
218 spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
219 list_add(&item->list, &opal_prd_msg_queue);
220 spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);
221 return err;
222}
223
224static ssize_t opal_prd_write(struct file *file, const char __user *buf,
225 size_t count, loff_t *ppos)
226{
227 struct opal_prd_msg_header hdr;
228 ssize_t size;
229 void *msg;
230 int rc;
231
232 size = sizeof(hdr);
233
234 if (count < size)
235 return -EINVAL;
236
237
238 rc = copy_from_user(&hdr, buf, sizeof(hdr));
239 if (rc)
240 return -EFAULT;
241
242 size = be16_to_cpu(hdr.size);
243
244 msg = kmalloc(size, GFP_KERNEL);
245 if (!msg)
246 return -ENOMEM;
247
248 rc = copy_from_user(msg, buf, size);
249 if (rc) {
250 size = -EFAULT;
251 goto out_free;
252 }
253
254 rc = opal_prd_msg(msg);
255 if (rc) {
256 pr_warn("write: opal_prd_msg returned %d\n", rc);
257 size = -EIO;
258 }
259
260out_free:
261 kfree(msg);
262
263 return size;
264}
265
266static int opal_prd_release(struct inode *inode, struct file *file)
267{
268 struct opal_prd_msg_header msg;
269
270 msg.size = cpu_to_be16(sizeof(msg));
271 msg.type = OPAL_PRD_MSG_TYPE_FINI;
272
273 opal_prd_msg((struct opal_prd_msg *)&msg);
274
275 atomic_xchg(&prd_usage, 0);
276
277 return 0;
278}
279
280static long opal_prd_ioctl(struct file *file, unsigned int cmd,
281 unsigned long param)
282{
283 struct opal_prd_info info;
284 struct opal_prd_scom scom;
285 int rc = 0;
286
287 switch (cmd) {
288 case OPAL_PRD_GET_INFO:
289 memset(&info, 0, sizeof(info));
290 info.version = OPAL_PRD_KERNEL_VERSION;
291 rc = copy_to_user((void __user *)param, &info, sizeof(info));
292 if (rc)
293 return -EFAULT;
294 break;
295
296 case OPAL_PRD_SCOM_READ:
297 rc = copy_from_user(&scom, (void __user *)param, sizeof(scom));
298 if (rc)
299 return -EFAULT;
300
301 scom.rc = opal_xscom_read(scom.chip, scom.addr,
302 (__be64 *)&scom.data);
303 scom.data = be64_to_cpu(scom.data);
304 pr_devel("ioctl SCOM_READ: chip %llx addr %016llx data %016llx rc %lld\n",
305 scom.chip, scom.addr, scom.data, scom.rc);
306
307 rc = copy_to_user((void __user *)param, &scom, sizeof(scom));
308 if (rc)
309 return -EFAULT;
310 break;
311
312 case OPAL_PRD_SCOM_WRITE:
313 rc = copy_from_user(&scom, (void __user *)param, sizeof(scom));
314 if (rc)
315 return -EFAULT;
316
317 scom.rc = opal_xscom_write(scom.chip, scom.addr, scom.data);
318 pr_devel("ioctl SCOM_WRITE: chip %llx addr %016llx data %016llx rc %lld\n",
319 scom.chip, scom.addr, scom.data, scom.rc);
320
321 rc = copy_to_user((void __user *)param, &scom, sizeof(scom));
322 if (rc)
323 return -EFAULT;
324 break;
325
326 default:
327 rc = -EINVAL;
328 }
329
330 return rc;
331}
332
333static const struct file_operations opal_prd_fops = {
334 .open = opal_prd_open,
335 .mmap = opal_prd_mmap,
336 .poll = opal_prd_poll,
337 .read = opal_prd_read,
338 .write = opal_prd_write,
339 .unlocked_ioctl = opal_prd_ioctl,
340 .release = opal_prd_release,
341 .owner = THIS_MODULE,
342};
343
344static struct miscdevice opal_prd_dev = {
345 .minor = MISC_DYNAMIC_MINOR,
346 .name = "opal-prd",
347 .fops = &opal_prd_fops,
348};
349
350
351static int opal_prd_msg_notifier(struct notifier_block *nb,
352 unsigned long msg_type, void *_msg)
353{
354 struct opal_prd_msg_queue_item *item;
355 struct opal_prd_msg_header *hdr;
356 struct opal_msg *msg = _msg;
357 int msg_size, item_size;
358 unsigned long flags;
359
360 if (msg_type != OPAL_MSG_PRD)
361 return 0;
362
363
364
365 hdr = (void *)msg->params;
366 msg_size = be16_to_cpu(hdr->size);
367 item_size = msg_size + sizeof(*item) - sizeof(item->msg);
368
369 item = kzalloc(item_size, GFP_ATOMIC);
370 if (!item)
371 return -ENOMEM;
372
373 memcpy(&item->msg, msg->params, msg_size);
374
375 spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
376 list_add_tail(&item->list, &opal_prd_msg_queue);
377 spin_unlock_irqrestore(&opal_prd_msg_queue_lock, flags);
378
379 wake_up_interruptible(&opal_prd_msg_wait);
380
381 return 0;
382}
383
384static struct notifier_block opal_prd_event_nb = {
385 .notifier_call = opal_prd_msg_notifier,
386 .next = NULL,
387 .priority = 0,
388};
389
390static int opal_prd_probe(struct platform_device *pdev)
391{
392 int rc;
393
394 if (!pdev || !pdev->dev.of_node)
395 return -ENODEV;
396
397
398
399
400 if (prd_node)
401 return -EBUSY;
402
403 prd_node = pdev->dev.of_node;
404
405 rc = opal_message_notifier_register(OPAL_MSG_PRD, &opal_prd_event_nb);
406 if (rc) {
407 pr_err("Couldn't register event notifier\n");
408 return rc;
409 }
410
411 rc = misc_register(&opal_prd_dev);
412 if (rc) {
413 pr_err("failed to register miscdev\n");
414 opal_message_notifier_unregister(OPAL_MSG_PRD,
415 &opal_prd_event_nb);
416 return rc;
417 }
418
419 return 0;
420}
421
422static int opal_prd_remove(struct platform_device *pdev)
423{
424 misc_deregister(&opal_prd_dev);
425 opal_message_notifier_unregister(OPAL_MSG_PRD, &opal_prd_event_nb);
426 return 0;
427}
428
429static const struct of_device_id opal_prd_match[] = {
430 { .compatible = "ibm,opal-prd" },
431 { },
432};
433
434static struct platform_driver opal_prd_driver = {
435 .driver = {
436 .name = "opal-prd",
437 .of_match_table = opal_prd_match,
438 },
439 .probe = opal_prd_probe,
440 .remove = opal_prd_remove,
441};
442
443module_platform_driver(opal_prd_driver);
444
445MODULE_DEVICE_TABLE(of, opal_prd_match);
446MODULE_DESCRIPTION("PowerNV OPAL runtime diagnostic driver");
447MODULE_LICENSE("GPL");
448
