xref: /openbmc/linux/arch/s390/pci/pci_clp.c (revision f21e49be)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright IBM Corp. 2012
4  *
5  * Author(s):
6  *   Jan Glauber <jang@linux.vnet.ibm.com>
7  */
8 
9 #define KMSG_COMPONENT "zpci"
10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
11 
12 #include <linux/compat.h>
13 #include <linux/kernel.h>
14 #include <linux/miscdevice.h>
15 #include <linux/slab.h>
16 #include <linux/err.h>
17 #include <linux/delay.h>
18 #include <linux/pci.h>
19 #include <linux/uaccess.h>
20 #include <asm/pci_debug.h>
21 #include <asm/pci_clp.h>
22 #include <asm/clp.h>
23 #include <uapi/asm/clp.h>
24 
25 bool zpci_unique_uid;
26 
27 void update_uid_checking(bool new)
28 {
29 	if (zpci_unique_uid != new)
30 		zpci_dbg(1, "uid checking:%d\n", new);
31 
32 	zpci_unique_uid = new;
33 }
34 
35 static inline void zpci_err_clp(unsigned int rsp, int rc)
36 {
37 	struct {
38 		unsigned int rsp;
39 		int rc;
40 	} __packed data = {rsp, rc};
41 
42 	zpci_err_hex(&data, sizeof(data));
43 }
44 
45 /*
46  * Call Logical Processor with c=1, lps=0 and command 1
47  * to get the bit mask of installed logical processors
48  */
49 static inline int clp_get_ilp(unsigned long *ilp)
50 {
51 	unsigned long mask;
52 	int cc = 3;
53 
54 	asm volatile (
55 		"	.insn	rrf,0xb9a00000,%[mask],%[cmd],8,0\n"
56 		"0:	ipm	%[cc]\n"
57 		"	srl	%[cc],28\n"
58 		"1:\n"
59 		EX_TABLE(0b, 1b)
60 		: [cc] "+d" (cc), [mask] "=d" (mask) : [cmd] "a" (1)
61 		: "cc");
62 	*ilp = mask;
63 	return cc;
64 }
65 
66 /*
67  * Call Logical Processor with c=0, the give constant lps and an lpcb request.
68  */
69 static __always_inline int clp_req(void *data, unsigned int lps)
70 {
71 	struct { u8 _[CLP_BLK_SIZE]; } *req = data;
72 	u64 ignored;
73 	int cc = 3;
74 
75 	asm volatile (
76 		"	.insn	rrf,0xb9a00000,%[ign],%[req],0,%[lps]\n"
77 		"0:	ipm	%[cc]\n"
78 		"	srl	%[cc],28\n"
79 		"1:\n"
80 		EX_TABLE(0b, 1b)
81 		: [cc] "+d" (cc), [ign] "=d" (ignored), "+m" (*req)
82 		: [req] "a" (req), [lps] "i" (lps)
83 		: "cc");
84 	return cc;
85 }
86 
87 static void *clp_alloc_block(gfp_t gfp_mask)
88 {
89 	return (void *) __get_free_pages(gfp_mask, get_order(CLP_BLK_SIZE));
90 }
91 
92 static void clp_free_block(void *ptr)
93 {
94 	free_pages((unsigned long) ptr, get_order(CLP_BLK_SIZE));
95 }
96 
97 static void clp_store_query_pci_fngrp(struct zpci_dev *zdev,
98 				      struct clp_rsp_query_pci_grp *response)
99 {
100 	zdev->tlb_refresh = response->refresh;
101 	zdev->dma_mask = response->dasm;
102 	zdev->msi_addr = response->msia;
103 	zdev->max_msi = response->noi;
104 	zdev->fmb_update = response->mui;
105 	zdev->version = response->version;
106 
107 	switch (response->version) {
108 	case 1:
109 		zdev->max_bus_speed = PCIE_SPEED_5_0GT;
110 		break;
111 	default:
112 		zdev->max_bus_speed = PCI_SPEED_UNKNOWN;
113 		break;
114 	}
115 }
116 
117 static int clp_query_pci_fngrp(struct zpci_dev *zdev, u8 pfgid)
118 {
119 	struct clp_req_rsp_query_pci_grp *rrb;
120 	int rc;
121 
122 	rrb = clp_alloc_block(GFP_KERNEL);
123 	if (!rrb)
124 		return -ENOMEM;
125 
126 	memset(rrb, 0, sizeof(*rrb));
127 	rrb->request.hdr.len = sizeof(rrb->request);
128 	rrb->request.hdr.cmd = CLP_QUERY_PCI_FNGRP;
129 	rrb->response.hdr.len = sizeof(rrb->response);
130 	rrb->request.pfgid = pfgid;
131 
132 	rc = clp_req(rrb, CLP_LPS_PCI);
133 	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK)
134 		clp_store_query_pci_fngrp(zdev, &rrb->response);
135 	else {
136 		zpci_err("Q PCI FGRP:\n");
137 		zpci_err_clp(rrb->response.hdr.rsp, rc);
138 		rc = -EIO;
139 	}
140 	clp_free_block(rrb);
141 	return rc;
142 }
143 
144 static int clp_store_query_pci_fn(struct zpci_dev *zdev,
145 				  struct clp_rsp_query_pci *response)
146 {
147 	int i;
148 
149 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
150 		zdev->bars[i].val = le32_to_cpu(response->bar[i]);
151 		zdev->bars[i].size = response->bar_size[i];
152 	}
153 	zdev->start_dma = response->sdma;
154 	zdev->end_dma = response->edma;
155 	zdev->pchid = response->pchid;
156 	zdev->pfgid = response->pfgid;
157 	zdev->pft = response->pft;
158 	zdev->vfn = response->vfn;
159 	zdev->port = response->port;
160 	zdev->uid = response->uid;
161 	zdev->fmb_length = sizeof(u32) * response->fmb_len;
162 	zdev->rid_available = response->rid_avail;
163 	zdev->is_physfn = response->is_physfn;
164 	if (!s390_pci_no_rid && zdev->rid_available)
165 		zdev->devfn = response->rid & ZPCI_RID_MASK_DEVFN;
166 
167 	memcpy(zdev->pfip, response->pfip, sizeof(zdev->pfip));
168 	if (response->util_str_avail) {
169 		memcpy(zdev->util_str, response->util_str,
170 		       sizeof(zdev->util_str));
171 		zdev->util_str_avail = 1;
172 	}
173 	zdev->mio_capable = response->mio_addr_avail;
174 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
175 		if (!(response->mio.valid & (1 << (PCI_STD_NUM_BARS - i - 1))))
176 			continue;
177 
178 		zdev->bars[i].mio_wb = (void __iomem *) response->mio.addr[i].wb;
179 		zdev->bars[i].mio_wt = (void __iomem *) response->mio.addr[i].wt;
180 	}
181 	return 0;
182 }
183 
184 int clp_query_pci_fn(struct zpci_dev *zdev)
185 {
186 	struct clp_req_rsp_query_pci *rrb;
187 	int rc;
188 
189 	rrb = clp_alloc_block(GFP_KERNEL);
190 	if (!rrb)
191 		return -ENOMEM;
192 
193 	memset(rrb, 0, sizeof(*rrb));
194 	rrb->request.hdr.len = sizeof(rrb->request);
195 	rrb->request.hdr.cmd = CLP_QUERY_PCI_FN;
196 	rrb->response.hdr.len = sizeof(rrb->response);
197 	rrb->request.fh = zdev->fh;
198 
199 	rc = clp_req(rrb, CLP_LPS_PCI);
200 	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) {
201 		rc = clp_store_query_pci_fn(zdev, &rrb->response);
202 		if (rc)
203 			goto out;
204 		rc = clp_query_pci_fngrp(zdev, rrb->response.pfgid);
205 	} else {
206 		zpci_err("Q PCI FN:\n");
207 		zpci_err_clp(rrb->response.hdr.rsp, rc);
208 		rc = -EIO;
209 	}
210 out:
211 	clp_free_block(rrb);
212 	return rc;
213 }
214 
215 /**
216  * clp_set_pci_fn() - Execute a command on a PCI function
217  * @zdev: Function that will be affected
218  * @fh: Out parameter for updated function handle
219  * @nr_dma_as: DMA address space number
220  * @command: The command code to execute
221  *
222  * Returns: 0 on success, < 0 for Linux errors (e.g. -ENOMEM), and
223  * > 0 for non-success platform responses
224  */
225 static int clp_set_pci_fn(struct zpci_dev *zdev, u32 *fh, u8 nr_dma_as, u8 command)
226 {
227 	struct clp_req_rsp_set_pci *rrb;
228 	int rc, retries = 100;
229 
230 	*fh = 0;
231 	rrb = clp_alloc_block(GFP_KERNEL);
232 	if (!rrb)
233 		return -ENOMEM;
234 
235 	do {
236 		memset(rrb, 0, sizeof(*rrb));
237 		rrb->request.hdr.len = sizeof(rrb->request);
238 		rrb->request.hdr.cmd = CLP_SET_PCI_FN;
239 		rrb->response.hdr.len = sizeof(rrb->response);
240 		rrb->request.fh = zdev->fh;
241 		rrb->request.oc = command;
242 		rrb->request.ndas = nr_dma_as;
243 
244 		rc = clp_req(rrb, CLP_LPS_PCI);
245 		if (rrb->response.hdr.rsp == CLP_RC_SETPCIFN_BUSY) {
246 			retries--;
247 			if (retries < 0)
248 				break;
249 			msleep(20);
250 		}
251 	} while (rrb->response.hdr.rsp == CLP_RC_SETPCIFN_BUSY);
252 
253 	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) {
254 		*fh = rrb->response.fh;
255 	} else {
256 		zpci_err("Set PCI FN:\n");
257 		zpci_err_clp(rrb->response.hdr.rsp, rc);
258 		if (!rc)
259 			rc = rrb->response.hdr.rsp;
260 	}
261 	clp_free_block(rrb);
262 	return rc;
263 }
264 
265 int clp_setup_writeback_mio(void)
266 {
267 	struct clp_req_rsp_slpc_pci *rrb;
268 	u8  wb_bit_pos;
269 	int rc;
270 
271 	rrb = clp_alloc_block(GFP_KERNEL);
272 	if (!rrb)
273 		return -ENOMEM;
274 
275 	memset(rrb, 0, sizeof(*rrb));
276 	rrb->request.hdr.len = sizeof(rrb->request);
277 	rrb->request.hdr.cmd = CLP_SLPC;
278 	rrb->response.hdr.len = sizeof(rrb->response);
279 
280 	rc = clp_req(rrb, CLP_LPS_PCI);
281 	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) {
282 		if (rrb->response.vwb) {
283 			wb_bit_pos = rrb->response.mio_wb;
284 			set_bit_inv(wb_bit_pos, &mio_wb_bit_mask);
285 			zpci_dbg(3, "wb bit: %d\n", wb_bit_pos);
286 		} else {
287 			zpci_dbg(3, "wb bit: n.a.\n");
288 		}
289 
290 	} else {
291 		zpci_err("SLPC PCI:\n");
292 		zpci_err_clp(rrb->response.hdr.rsp, rc);
293 		rc = -EIO;
294 	}
295 	clp_free_block(rrb);
296 	return rc;
297 }
298 
299 int clp_enable_fh(struct zpci_dev *zdev, u32 *fh, u8 nr_dma_as)
300 {
301 	int rc;
302 
303 	rc = clp_set_pci_fn(zdev, fh, nr_dma_as, CLP_SET_ENABLE_PCI_FN);
304 	zpci_dbg(3, "ena fid:%x, fh:%x, rc:%d\n", zdev->fid, *fh, rc);
305 	if (!rc && zpci_use_mio(zdev)) {
306 		rc = clp_set_pci_fn(zdev, fh, nr_dma_as, CLP_SET_ENABLE_MIO);
307 		zpci_dbg(3, "ena mio fid:%x, fh:%x, rc:%d\n",
308 				zdev->fid, *fh, rc);
309 		if (rc)
310 			clp_disable_fh(zdev, fh);
311 	}
312 	return rc;
313 }
314 
315 int clp_disable_fh(struct zpci_dev *zdev, u32 *fh)
316 {
317 	int rc;
318 
319 	if (!zdev_enabled(zdev))
320 		return 0;
321 
322 	rc = clp_set_pci_fn(zdev, fh, 0, CLP_SET_DISABLE_PCI_FN);
323 	zpci_dbg(3, "dis fid:%x, fh:%x, rc:%d\n", zdev->fid, *fh, rc);
324 	return rc;
325 }
326 
327 static int clp_list_pci_req(struct clp_req_rsp_list_pci *rrb,
328 			    u64 *resume_token, int *nentries)
329 {
330 	int rc;
331 
332 	memset(rrb, 0, sizeof(*rrb));
333 	rrb->request.hdr.len = sizeof(rrb->request);
334 	rrb->request.hdr.cmd = CLP_LIST_PCI;
335 	/* store as many entries as possible */
336 	rrb->response.hdr.len = CLP_BLK_SIZE - LIST_PCI_HDR_LEN;
337 	rrb->request.resume_token = *resume_token;
338 
339 	/* Get PCI function handle list */
340 	rc = clp_req(rrb, CLP_LPS_PCI);
341 	if (rc || rrb->response.hdr.rsp != CLP_RC_OK) {
342 		zpci_err("List PCI FN:\n");
343 		zpci_err_clp(rrb->response.hdr.rsp, rc);
344 		return -EIO;
345 	}
346 
347 	update_uid_checking(rrb->response.uid_checking);
348 	WARN_ON_ONCE(rrb->response.entry_size !=
349 		sizeof(struct clp_fh_list_entry));
350 
351 	*nentries = (rrb->response.hdr.len - LIST_PCI_HDR_LEN) /
352 		rrb->response.entry_size;
353 	*resume_token = rrb->response.resume_token;
354 
355 	return rc;
356 }
357 
358 static int clp_list_pci(struct clp_req_rsp_list_pci *rrb, void *data,
359 			void (*cb)(struct clp_fh_list_entry *, void *))
360 {
361 	u64 resume_token = 0;
362 	int nentries, i, rc;
363 
364 	do {
365 		rc = clp_list_pci_req(rrb, &resume_token, &nentries);
366 		if (rc)
367 			return rc;
368 		for (i = 0; i < nentries; i++)
369 			cb(&rrb->response.fh_list[i], data);
370 	} while (resume_token);
371 
372 	return rc;
373 }
374 
375 static int clp_find_pci(struct clp_req_rsp_list_pci *rrb, u32 fid,
376 			struct clp_fh_list_entry *entry)
377 {
378 	struct clp_fh_list_entry *fh_list;
379 	u64 resume_token = 0;
380 	int nentries, i, rc;
381 
382 	do {
383 		rc = clp_list_pci_req(rrb, &resume_token, &nentries);
384 		if (rc)
385 			return rc;
386 		fh_list = rrb->response.fh_list;
387 		for (i = 0; i < nentries; i++) {
388 			if (fh_list[i].fid == fid) {
389 				*entry = fh_list[i];
390 				return 0;
391 			}
392 		}
393 	} while (resume_token);
394 
395 	return -ENODEV;
396 }
397 
398 static void __clp_add(struct clp_fh_list_entry *entry, void *data)
399 {
400 	struct zpci_dev *zdev;
401 
402 	if (!entry->vendor_id)
403 		return;
404 
405 	zdev = get_zdev_by_fid(entry->fid);
406 	if (!zdev)
407 		zpci_create_device(entry->fid, entry->fh, entry->config_state);
408 }
409 
410 int clp_scan_pci_devices(void)
411 {
412 	struct clp_req_rsp_list_pci *rrb;
413 	int rc;
414 
415 	rrb = clp_alloc_block(GFP_KERNEL);
416 	if (!rrb)
417 		return -ENOMEM;
418 
419 	rc = clp_list_pci(rrb, NULL, __clp_add);
420 
421 	clp_free_block(rrb);
422 	return rc;
423 }
424 
425 /*
426  * Get the current function handle of the function matching @fid
427  */
428 int clp_refresh_fh(u32 fid, u32 *fh)
429 {
430 	struct clp_req_rsp_list_pci *rrb;
431 	struct clp_fh_list_entry entry;
432 	int rc;
433 
434 	rrb = clp_alloc_block(GFP_NOWAIT);
435 	if (!rrb)
436 		return -ENOMEM;
437 
438 	rc = clp_find_pci(rrb, fid, &entry);
439 	if (!rc)
440 		*fh = entry.fh;
441 
442 	clp_free_block(rrb);
443 	return rc;
444 }
445 
446 int clp_get_state(u32 fid, enum zpci_state *state)
447 {
448 	struct clp_req_rsp_list_pci *rrb;
449 	struct clp_fh_list_entry entry;
450 	int rc;
451 
452 	rrb = clp_alloc_block(GFP_ATOMIC);
453 	if (!rrb)
454 		return -ENOMEM;
455 
456 	rc = clp_find_pci(rrb, fid, &entry);
457 	if (!rc) {
458 		*state = entry.config_state;
459 	} else if (rc == -ENODEV) {
460 		*state = ZPCI_FN_STATE_RESERVED;
461 		rc = 0;
462 	}
463 
464 	clp_free_block(rrb);
465 	return rc;
466 }
467 
468 static int clp_base_slpc(struct clp_req *req, struct clp_req_rsp_slpc *lpcb)
469 {
470 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
471 
472 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
473 	    lpcb->response.hdr.len > limit)
474 		return -EINVAL;
475 	return clp_req(lpcb, CLP_LPS_BASE) ? -EOPNOTSUPP : 0;
476 }
477 
478 static int clp_base_command(struct clp_req *req, struct clp_req_hdr *lpcb)
479 {
480 	switch (lpcb->cmd) {
481 	case 0x0001: /* store logical-processor characteristics */
482 		return clp_base_slpc(req, (void *) lpcb);
483 	default:
484 		return -EINVAL;
485 	}
486 }
487 
488 static int clp_pci_slpc(struct clp_req *req, struct clp_req_rsp_slpc_pci *lpcb)
489 {
490 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
491 
492 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
493 	    lpcb->response.hdr.len > limit)
494 		return -EINVAL;
495 	return clp_req(lpcb, CLP_LPS_PCI) ? -EOPNOTSUPP : 0;
496 }
497 
498 static int clp_pci_list(struct clp_req *req, struct clp_req_rsp_list_pci *lpcb)
499 {
500 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
501 
502 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
503 	    lpcb->response.hdr.len > limit)
504 		return -EINVAL;
505 	if (lpcb->request.reserved2 != 0)
506 		return -EINVAL;
507 	return clp_req(lpcb, CLP_LPS_PCI) ? -EOPNOTSUPP : 0;
508 }
509 
510 static int clp_pci_query(struct clp_req *req,
511 			 struct clp_req_rsp_query_pci *lpcb)
512 {
513 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
514 
515 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
516 	    lpcb->response.hdr.len > limit)
517 		return -EINVAL;
518 	if (lpcb->request.reserved2 != 0 || lpcb->request.reserved3 != 0)
519 		return -EINVAL;
520 	return clp_req(lpcb, CLP_LPS_PCI) ? -EOPNOTSUPP : 0;
521 }
522 
523 static int clp_pci_query_grp(struct clp_req *req,
524 			     struct clp_req_rsp_query_pci_grp *lpcb)
525 {
526 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
527 
528 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
529 	    lpcb->response.hdr.len > limit)
530 		return -EINVAL;
531 	if (lpcb->request.reserved2 != 0 || lpcb->request.reserved3 != 0 ||
532 	    lpcb->request.reserved4 != 0)
533 		return -EINVAL;
534 	return clp_req(lpcb, CLP_LPS_PCI) ? -EOPNOTSUPP : 0;
535 }
536 
537 static int clp_pci_command(struct clp_req *req, struct clp_req_hdr *lpcb)
538 {
539 	switch (lpcb->cmd) {
540 	case 0x0001: /* store logical-processor characteristics */
541 		return clp_pci_slpc(req, (void *) lpcb);
542 	case 0x0002: /* list PCI functions */
543 		return clp_pci_list(req, (void *) lpcb);
544 	case 0x0003: /* query PCI function */
545 		return clp_pci_query(req, (void *) lpcb);
546 	case 0x0004: /* query PCI function group */
547 		return clp_pci_query_grp(req, (void *) lpcb);
548 	default:
549 		return -EINVAL;
550 	}
551 }
552 
553 static int clp_normal_command(struct clp_req *req)
554 {
555 	struct clp_req_hdr *lpcb;
556 	void __user *uptr;
557 	int rc;
558 
559 	rc = -EINVAL;
560 	if (req->lps != 0 && req->lps != 2)
561 		goto out;
562 
563 	rc = -ENOMEM;
564 	lpcb = clp_alloc_block(GFP_KERNEL);
565 	if (!lpcb)
566 		goto out;
567 
568 	rc = -EFAULT;
569 	uptr = (void __force __user *)(unsigned long) req->data_p;
570 	if (copy_from_user(lpcb, uptr, PAGE_SIZE) != 0)
571 		goto out_free;
572 
573 	rc = -EINVAL;
574 	if (lpcb->fmt != 0 || lpcb->reserved1 != 0 || lpcb->reserved2 != 0)
575 		goto out_free;
576 
577 	switch (req->lps) {
578 	case 0:
579 		rc = clp_base_command(req, lpcb);
580 		break;
581 	case 2:
582 		rc = clp_pci_command(req, lpcb);
583 		break;
584 	}
585 	if (rc)
586 		goto out_free;
587 
588 	rc = -EFAULT;
589 	if (copy_to_user(uptr, lpcb, PAGE_SIZE) != 0)
590 		goto out_free;
591 
592 	rc = 0;
593 
594 out_free:
595 	clp_free_block(lpcb);
596 out:
597 	return rc;
598 }
599 
600 static int clp_immediate_command(struct clp_req *req)
601 {
602 	void __user *uptr;
603 	unsigned long ilp;
604 	int exists;
605 
606 	if (req->cmd > 1 || clp_get_ilp(&ilp) != 0)
607 		return -EINVAL;
608 
609 	uptr = (void __force __user *)(unsigned long) req->data_p;
610 	if (req->cmd == 0) {
611 		/* Command code 0: test for a specific processor */
612 		exists = test_bit_inv(req->lps, &ilp);
613 		return put_user(exists, (int __user *) uptr);
614 	}
615 	/* Command code 1: return bit mask of installed processors */
616 	return put_user(ilp, (unsigned long __user *) uptr);
617 }
618 
619 static long clp_misc_ioctl(struct file *filp, unsigned int cmd,
620 			   unsigned long arg)
621 {
622 	struct clp_req req;
623 	void __user *argp;
624 
625 	if (cmd != CLP_SYNC)
626 		return -EINVAL;
627 
628 	argp = is_compat_task() ? compat_ptr(arg) : (void __user *) arg;
629 	if (copy_from_user(&req, argp, sizeof(req)))
630 		return -EFAULT;
631 	if (req.r != 0)
632 		return -EINVAL;
633 	return req.c ? clp_immediate_command(&req) : clp_normal_command(&req);
634 }
635 
636 static int clp_misc_release(struct inode *inode, struct file *filp)
637 {
638 	return 0;
639 }
640 
641 static const struct file_operations clp_misc_fops = {
642 	.owner = THIS_MODULE,
643 	.open = nonseekable_open,
644 	.release = clp_misc_release,
645 	.unlocked_ioctl = clp_misc_ioctl,
646 	.compat_ioctl = clp_misc_ioctl,
647 	.llseek = no_llseek,
648 };
649 
650 static struct miscdevice clp_misc_device = {
651 	.minor = MISC_DYNAMIC_MINOR,
652 	.name = "clp",
653 	.fops = &clp_misc_fops,
654 };
655 
656 static int __init clp_misc_init(void)
657 {
658 	return misc_register(&clp_misc_device);
659 }
660 
661 device_initcall(clp_misc_init);
662