xref: /linux/arch/s390/pci/pci_clp.c (revision 3f0a50f345f78183f6e9b39c2f45ca5dcaa511ca)
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/asm-extable.h>
21 #include <asm/pci_debug.h>
22 #include <asm/pci_clp.h>
23 #include <asm/clp.h>
24 #include <uapi/asm/clp.h>
25 
26 #include "pci_bus.h"
27 
28 bool zpci_unique_uid;
29 
30 void update_uid_checking(bool new)
31 {
32 	if (zpci_unique_uid != new)
33 		zpci_dbg(1, "uid checking:%d\n", new);
34 
35 	zpci_unique_uid = new;
36 }
37 
38 static inline void zpci_err_clp(unsigned int rsp, int rc)
39 {
40 	struct {
41 		unsigned int rsp;
42 		int rc;
43 	} __packed data = {rsp, rc};
44 
45 	zpci_err_hex(&data, sizeof(data));
46 }
47 
48 /*
49  * Call Logical Processor with c=1, lps=0 and command 1
50  * to get the bit mask of installed logical processors
51  */
52 static inline int clp_get_ilp(unsigned long *ilp)
53 {
54 	unsigned long mask;
55 	int cc = 3;
56 
57 	asm volatile (
58 		"	.insn	rrf,0xb9a00000,%[mask],%[cmd],8,0\n"
59 		"0:	ipm	%[cc]\n"
60 		"	srl	%[cc],28\n"
61 		"1:\n"
62 		EX_TABLE(0b, 1b)
63 		: [cc] "+d" (cc), [mask] "=d" (mask) : [cmd] "a" (1)
64 		: "cc");
65 	*ilp = mask;
66 	return cc;
67 }
68 
69 /*
70  * Call Logical Processor with c=0, the give constant lps and an lpcb request.
71  */
72 static __always_inline int clp_req(void *data, unsigned int lps)
73 {
74 	struct { u8 _[CLP_BLK_SIZE]; } *req = data;
75 	u64 ignored;
76 	int cc = 3;
77 
78 	asm volatile (
79 		"	.insn	rrf,0xb9a00000,%[ign],%[req],0,%[lps]\n"
80 		"0:	ipm	%[cc]\n"
81 		"	srl	%[cc],28\n"
82 		"1:\n"
83 		EX_TABLE(0b, 1b)
84 		: [cc] "+d" (cc), [ign] "=d" (ignored), "+m" (*req)
85 		: [req] "a" (req), [lps] "i" (lps)
86 		: "cc");
87 	return cc;
88 }
89 
90 static void *clp_alloc_block(gfp_t gfp_mask)
91 {
92 	return (void *) __get_free_pages(gfp_mask, get_order(CLP_BLK_SIZE));
93 }
94 
95 static void clp_free_block(void *ptr)
96 {
97 	free_pages((unsigned long) ptr, get_order(CLP_BLK_SIZE));
98 }
99 
100 static void clp_store_query_pci_fngrp(struct zpci_dev *zdev,
101 				      struct clp_rsp_query_pci_grp *response)
102 {
103 	zdev->tlb_refresh = response->refresh;
104 	zdev->dma_mask = response->dasm;
105 	zdev->msi_addr = response->msia;
106 	zdev->max_msi = response->noi;
107 	zdev->fmb_update = response->mui;
108 	zdev->version = response->version;
109 
110 	switch (response->version) {
111 	case 1:
112 		zdev->max_bus_speed = PCIE_SPEED_5_0GT;
113 		break;
114 	default:
115 		zdev->max_bus_speed = PCI_SPEED_UNKNOWN;
116 		break;
117 	}
118 }
119 
120 static int clp_query_pci_fngrp(struct zpci_dev *zdev, u8 pfgid)
121 {
122 	struct clp_req_rsp_query_pci_grp *rrb;
123 	int rc;
124 
125 	rrb = clp_alloc_block(GFP_KERNEL);
126 	if (!rrb)
127 		return -ENOMEM;
128 
129 	memset(rrb, 0, sizeof(*rrb));
130 	rrb->request.hdr.len = sizeof(rrb->request);
131 	rrb->request.hdr.cmd = CLP_QUERY_PCI_FNGRP;
132 	rrb->response.hdr.len = sizeof(rrb->response);
133 	rrb->request.pfgid = pfgid;
134 
135 	rc = clp_req(rrb, CLP_LPS_PCI);
136 	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK)
137 		clp_store_query_pci_fngrp(zdev, &rrb->response);
138 	else {
139 		zpci_err("Q PCI FGRP:\n");
140 		zpci_err_clp(rrb->response.hdr.rsp, rc);
141 		rc = -EIO;
142 	}
143 	clp_free_block(rrb);
144 	return rc;
145 }
146 
147 static int clp_store_query_pci_fn(struct zpci_dev *zdev,
148 				  struct clp_rsp_query_pci *response)
149 {
150 	int i;
151 
152 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
153 		zdev->bars[i].val = le32_to_cpu(response->bar[i]);
154 		zdev->bars[i].size = response->bar_size[i];
155 	}
156 	zdev->start_dma = response->sdma;
157 	zdev->end_dma = response->edma;
158 	zdev->pchid = response->pchid;
159 	zdev->pfgid = response->pfgid;
160 	zdev->pft = response->pft;
161 	zdev->vfn = response->vfn;
162 	zdev->port = response->port;
163 	zdev->uid = response->uid;
164 	zdev->fmb_length = sizeof(u32) * response->fmb_len;
165 	zdev->rid_available = response->rid_avail;
166 	zdev->is_physfn = response->is_physfn;
167 	if (!s390_pci_no_rid && zdev->rid_available)
168 		zdev->devfn = response->rid & ZPCI_RID_MASK_DEVFN;
169 
170 	memcpy(zdev->pfip, response->pfip, sizeof(zdev->pfip));
171 	if (response->util_str_avail) {
172 		memcpy(zdev->util_str, response->util_str,
173 		       sizeof(zdev->util_str));
174 		zdev->util_str_avail = 1;
175 	}
176 	zdev->mio_capable = response->mio_addr_avail;
177 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
178 		if (!(response->mio.valid & (1 << (PCI_STD_NUM_BARS - i - 1))))
179 			continue;
180 
181 		zdev->bars[i].mio_wb = (void __iomem *) response->mio.addr[i].wb;
182 		zdev->bars[i].mio_wt = (void __iomem *) response->mio.addr[i].wt;
183 	}
184 	return 0;
185 }
186 
187 int clp_query_pci_fn(struct zpci_dev *zdev)
188 {
189 	struct clp_req_rsp_query_pci *rrb;
190 	int rc;
191 
192 	rrb = clp_alloc_block(GFP_KERNEL);
193 	if (!rrb)
194 		return -ENOMEM;
195 
196 	memset(rrb, 0, sizeof(*rrb));
197 	rrb->request.hdr.len = sizeof(rrb->request);
198 	rrb->request.hdr.cmd = CLP_QUERY_PCI_FN;
199 	rrb->response.hdr.len = sizeof(rrb->response);
200 	rrb->request.fh = zdev->fh;
201 
202 	rc = clp_req(rrb, CLP_LPS_PCI);
203 	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) {
204 		rc = clp_store_query_pci_fn(zdev, &rrb->response);
205 		if (rc)
206 			goto out;
207 		rc = clp_query_pci_fngrp(zdev, rrb->response.pfgid);
208 	} else {
209 		zpci_err("Q PCI FN:\n");
210 		zpci_err_clp(rrb->response.hdr.rsp, rc);
211 		rc = -EIO;
212 	}
213 out:
214 	clp_free_block(rrb);
215 	return rc;
216 }
217 
218 /**
219  * clp_set_pci_fn() - Execute a command on a PCI function
220  * @zdev: Function that will be affected
221  * @fh: Out parameter for updated function handle
222  * @nr_dma_as: DMA address space number
223  * @command: The command code to execute
224  *
225  * Returns: 0 on success, < 0 for Linux errors (e.g. -ENOMEM), and
226  * > 0 for non-success platform responses
227  */
228 static int clp_set_pci_fn(struct zpci_dev *zdev, u32 *fh, u8 nr_dma_as, u8 command)
229 {
230 	struct clp_req_rsp_set_pci *rrb;
231 	int rc, retries = 100;
232 
233 	*fh = 0;
234 	rrb = clp_alloc_block(GFP_KERNEL);
235 	if (!rrb)
236 		return -ENOMEM;
237 
238 	do {
239 		memset(rrb, 0, sizeof(*rrb));
240 		rrb->request.hdr.len = sizeof(rrb->request);
241 		rrb->request.hdr.cmd = CLP_SET_PCI_FN;
242 		rrb->response.hdr.len = sizeof(rrb->response);
243 		rrb->request.fh = zdev->fh;
244 		rrb->request.oc = command;
245 		rrb->request.ndas = nr_dma_as;
246 
247 		rc = clp_req(rrb, CLP_LPS_PCI);
248 		if (rrb->response.hdr.rsp == CLP_RC_SETPCIFN_BUSY) {
249 			retries--;
250 			if (retries < 0)
251 				break;
252 			msleep(20);
253 		}
254 	} while (rrb->response.hdr.rsp == CLP_RC_SETPCIFN_BUSY);
255 
256 	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) {
257 		*fh = rrb->response.fh;
258 	} else {
259 		zpci_err("Set PCI FN:\n");
260 		zpci_err_clp(rrb->response.hdr.rsp, rc);
261 		if (!rc)
262 			rc = rrb->response.hdr.rsp;
263 	}
264 	clp_free_block(rrb);
265 	return rc;
266 }
267 
268 int clp_setup_writeback_mio(void)
269 {
270 	struct clp_req_rsp_slpc_pci *rrb;
271 	u8  wb_bit_pos;
272 	int rc;
273 
274 	rrb = clp_alloc_block(GFP_KERNEL);
275 	if (!rrb)
276 		return -ENOMEM;
277 
278 	memset(rrb, 0, sizeof(*rrb));
279 	rrb->request.hdr.len = sizeof(rrb->request);
280 	rrb->request.hdr.cmd = CLP_SLPC;
281 	rrb->response.hdr.len = sizeof(rrb->response);
282 
283 	rc = clp_req(rrb, CLP_LPS_PCI);
284 	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) {
285 		if (rrb->response.vwb) {
286 			wb_bit_pos = rrb->response.mio_wb;
287 			set_bit_inv(wb_bit_pos, &mio_wb_bit_mask);
288 			zpci_dbg(3, "wb bit: %d\n", wb_bit_pos);
289 		} else {
290 			zpci_dbg(3, "wb bit: n.a.\n");
291 		}
292 
293 	} else {
294 		zpci_err("SLPC PCI:\n");
295 		zpci_err_clp(rrb->response.hdr.rsp, rc);
296 		rc = -EIO;
297 	}
298 	clp_free_block(rrb);
299 	return rc;
300 }
301 
302 int clp_enable_fh(struct zpci_dev *zdev, u32 *fh, u8 nr_dma_as)
303 {
304 	int rc;
305 
306 	rc = clp_set_pci_fn(zdev, fh, nr_dma_as, CLP_SET_ENABLE_PCI_FN);
307 	zpci_dbg(3, "ena fid:%x, fh:%x, rc:%d\n", zdev->fid, *fh, rc);
308 	if (!rc && zpci_use_mio(zdev)) {
309 		rc = clp_set_pci_fn(zdev, fh, nr_dma_as, CLP_SET_ENABLE_MIO);
310 		zpci_dbg(3, "ena mio fid:%x, fh:%x, rc:%d\n",
311 				zdev->fid, *fh, rc);
312 		if (rc)
313 			clp_disable_fh(zdev, fh);
314 	}
315 	return rc;
316 }
317 
318 int clp_disable_fh(struct zpci_dev *zdev, u32 *fh)
319 {
320 	int rc;
321 
322 	if (!zdev_enabled(zdev))
323 		return 0;
324 
325 	rc = clp_set_pci_fn(zdev, fh, 0, CLP_SET_DISABLE_PCI_FN);
326 	zpci_dbg(3, "dis fid:%x, fh:%x, rc:%d\n", zdev->fid, *fh, rc);
327 	return rc;
328 }
329 
330 static int clp_list_pci_req(struct clp_req_rsp_list_pci *rrb,
331 			    u64 *resume_token, int *nentries)
332 {
333 	int rc;
334 
335 	memset(rrb, 0, sizeof(*rrb));
336 	rrb->request.hdr.len = sizeof(rrb->request);
337 	rrb->request.hdr.cmd = CLP_LIST_PCI;
338 	/* store as many entries as possible */
339 	rrb->response.hdr.len = CLP_BLK_SIZE - LIST_PCI_HDR_LEN;
340 	rrb->request.resume_token = *resume_token;
341 
342 	/* Get PCI function handle list */
343 	rc = clp_req(rrb, CLP_LPS_PCI);
344 	if (rc || rrb->response.hdr.rsp != CLP_RC_OK) {
345 		zpci_err("List PCI FN:\n");
346 		zpci_err_clp(rrb->response.hdr.rsp, rc);
347 		return -EIO;
348 	}
349 
350 	update_uid_checking(rrb->response.uid_checking);
351 	WARN_ON_ONCE(rrb->response.entry_size !=
352 		sizeof(struct clp_fh_list_entry));
353 
354 	*nentries = (rrb->response.hdr.len - LIST_PCI_HDR_LEN) /
355 		rrb->response.entry_size;
356 	*resume_token = rrb->response.resume_token;
357 
358 	return rc;
359 }
360 
361 static int clp_list_pci(struct clp_req_rsp_list_pci *rrb, void *data,
362 			void (*cb)(struct clp_fh_list_entry *, void *))
363 {
364 	u64 resume_token = 0;
365 	int nentries, i, rc;
366 
367 	do {
368 		rc = clp_list_pci_req(rrb, &resume_token, &nentries);
369 		if (rc)
370 			return rc;
371 		for (i = 0; i < nentries; i++)
372 			cb(&rrb->response.fh_list[i], data);
373 	} while (resume_token);
374 
375 	return rc;
376 }
377 
378 static int clp_find_pci(struct clp_req_rsp_list_pci *rrb, u32 fid,
379 			struct clp_fh_list_entry *entry)
380 {
381 	struct clp_fh_list_entry *fh_list;
382 	u64 resume_token = 0;
383 	int nentries, i, rc;
384 
385 	do {
386 		rc = clp_list_pci_req(rrb, &resume_token, &nentries);
387 		if (rc)
388 			return rc;
389 		fh_list = rrb->response.fh_list;
390 		for (i = 0; i < nentries; i++) {
391 			if (fh_list[i].fid == fid) {
392 				*entry = fh_list[i];
393 				return 0;
394 			}
395 		}
396 	} while (resume_token);
397 
398 	return -ENODEV;
399 }
400 
401 static void __clp_add(struct clp_fh_list_entry *entry, void *data)
402 {
403 	struct zpci_dev *zdev;
404 
405 	if (!entry->vendor_id)
406 		return;
407 
408 	zdev = get_zdev_by_fid(entry->fid);
409 	if (zdev) {
410 		zpci_zdev_put(zdev);
411 		return;
412 	}
413 	zpci_create_device(entry->fid, entry->fh, entry->config_state);
414 }
415 
416 int clp_scan_pci_devices(void)
417 {
418 	struct clp_req_rsp_list_pci *rrb;
419 	int rc;
420 
421 	rrb = clp_alloc_block(GFP_KERNEL);
422 	if (!rrb)
423 		return -ENOMEM;
424 
425 	rc = clp_list_pci(rrb, NULL, __clp_add);
426 
427 	clp_free_block(rrb);
428 	return rc;
429 }
430 
431 /*
432  * Get the current function handle of the function matching @fid
433  */
434 int clp_refresh_fh(u32 fid, u32 *fh)
435 {
436 	struct clp_req_rsp_list_pci *rrb;
437 	struct clp_fh_list_entry entry;
438 	int rc;
439 
440 	rrb = clp_alloc_block(GFP_NOWAIT);
441 	if (!rrb)
442 		return -ENOMEM;
443 
444 	rc = clp_find_pci(rrb, fid, &entry);
445 	if (!rc)
446 		*fh = entry.fh;
447 
448 	clp_free_block(rrb);
449 	return rc;
450 }
451 
452 int clp_get_state(u32 fid, enum zpci_state *state)
453 {
454 	struct clp_req_rsp_list_pci *rrb;
455 	struct clp_fh_list_entry entry;
456 	int rc;
457 
458 	rrb = clp_alloc_block(GFP_ATOMIC);
459 	if (!rrb)
460 		return -ENOMEM;
461 
462 	rc = clp_find_pci(rrb, fid, &entry);
463 	if (!rc) {
464 		*state = entry.config_state;
465 	} else if (rc == -ENODEV) {
466 		*state = ZPCI_FN_STATE_RESERVED;
467 		rc = 0;
468 	}
469 
470 	clp_free_block(rrb);
471 	return rc;
472 }
473 
474 static int clp_base_slpc(struct clp_req *req, struct clp_req_rsp_slpc *lpcb)
475 {
476 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
477 
478 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
479 	    lpcb->response.hdr.len > limit)
480 		return -EINVAL;
481 	return clp_req(lpcb, CLP_LPS_BASE) ? -EOPNOTSUPP : 0;
482 }
483 
484 static int clp_base_command(struct clp_req *req, struct clp_req_hdr *lpcb)
485 {
486 	switch (lpcb->cmd) {
487 	case 0x0001: /* store logical-processor characteristics */
488 		return clp_base_slpc(req, (void *) lpcb);
489 	default:
490 		return -EINVAL;
491 	}
492 }
493 
494 static int clp_pci_slpc(struct clp_req *req, struct clp_req_rsp_slpc_pci *lpcb)
495 {
496 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
497 
498 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
499 	    lpcb->response.hdr.len > limit)
500 		return -EINVAL;
501 	return clp_req(lpcb, CLP_LPS_PCI) ? -EOPNOTSUPP : 0;
502 }
503 
504 static int clp_pci_list(struct clp_req *req, struct clp_req_rsp_list_pci *lpcb)
505 {
506 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
507 
508 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
509 	    lpcb->response.hdr.len > limit)
510 		return -EINVAL;
511 	if (lpcb->request.reserved2 != 0)
512 		return -EINVAL;
513 	return clp_req(lpcb, CLP_LPS_PCI) ? -EOPNOTSUPP : 0;
514 }
515 
516 static int clp_pci_query(struct clp_req *req,
517 			 struct clp_req_rsp_query_pci *lpcb)
518 {
519 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
520 
521 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
522 	    lpcb->response.hdr.len > limit)
523 		return -EINVAL;
524 	if (lpcb->request.reserved2 != 0 || lpcb->request.reserved3 != 0)
525 		return -EINVAL;
526 	return clp_req(lpcb, CLP_LPS_PCI) ? -EOPNOTSUPP : 0;
527 }
528 
529 static int clp_pci_query_grp(struct clp_req *req,
530 			     struct clp_req_rsp_query_pci_grp *lpcb)
531 {
532 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
533 
534 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
535 	    lpcb->response.hdr.len > limit)
536 		return -EINVAL;
537 	if (lpcb->request.reserved2 != 0 || lpcb->request.reserved3 != 0 ||
538 	    lpcb->request.reserved4 != 0)
539 		return -EINVAL;
540 	return clp_req(lpcb, CLP_LPS_PCI) ? -EOPNOTSUPP : 0;
541 }
542 
543 static int clp_pci_command(struct clp_req *req, struct clp_req_hdr *lpcb)
544 {
545 	switch (lpcb->cmd) {
546 	case 0x0001: /* store logical-processor characteristics */
547 		return clp_pci_slpc(req, (void *) lpcb);
548 	case 0x0002: /* list PCI functions */
549 		return clp_pci_list(req, (void *) lpcb);
550 	case 0x0003: /* query PCI function */
551 		return clp_pci_query(req, (void *) lpcb);
552 	case 0x0004: /* query PCI function group */
553 		return clp_pci_query_grp(req, (void *) lpcb);
554 	default:
555 		return -EINVAL;
556 	}
557 }
558 
559 static int clp_normal_command(struct clp_req *req)
560 {
561 	struct clp_req_hdr *lpcb;
562 	void __user *uptr;
563 	int rc;
564 
565 	rc = -EINVAL;
566 	if (req->lps != 0 && req->lps != 2)
567 		goto out;
568 
569 	rc = -ENOMEM;
570 	lpcb = clp_alloc_block(GFP_KERNEL);
571 	if (!lpcb)
572 		goto out;
573 
574 	rc = -EFAULT;
575 	uptr = (void __force __user *)(unsigned long) req->data_p;
576 	if (copy_from_user(lpcb, uptr, PAGE_SIZE) != 0)
577 		goto out_free;
578 
579 	rc = -EINVAL;
580 	if (lpcb->fmt != 0 || lpcb->reserved1 != 0 || lpcb->reserved2 != 0)
581 		goto out_free;
582 
583 	switch (req->lps) {
584 	case 0:
585 		rc = clp_base_command(req, lpcb);
586 		break;
587 	case 2:
588 		rc = clp_pci_command(req, lpcb);
589 		break;
590 	}
591 	if (rc)
592 		goto out_free;
593 
594 	rc = -EFAULT;
595 	if (copy_to_user(uptr, lpcb, PAGE_SIZE) != 0)
596 		goto out_free;
597 
598 	rc = 0;
599 
600 out_free:
601 	clp_free_block(lpcb);
602 out:
603 	return rc;
604 }
605 
606 static int clp_immediate_command(struct clp_req *req)
607 {
608 	void __user *uptr;
609 	unsigned long ilp;
610 	int exists;
611 
612 	if (req->cmd > 1 || clp_get_ilp(&ilp) != 0)
613 		return -EINVAL;
614 
615 	uptr = (void __force __user *)(unsigned long) req->data_p;
616 	if (req->cmd == 0) {
617 		/* Command code 0: test for a specific processor */
618 		exists = test_bit_inv(req->lps, &ilp);
619 		return put_user(exists, (int __user *) uptr);
620 	}
621 	/* Command code 1: return bit mask of installed processors */
622 	return put_user(ilp, (unsigned long __user *) uptr);
623 }
624 
625 static long clp_misc_ioctl(struct file *filp, unsigned int cmd,
626 			   unsigned long arg)
627 {
628 	struct clp_req req;
629 	void __user *argp;
630 
631 	if (cmd != CLP_SYNC)
632 		return -EINVAL;
633 
634 	argp = is_compat_task() ? compat_ptr(arg) : (void __user *) arg;
635 	if (copy_from_user(&req, argp, sizeof(req)))
636 		return -EFAULT;
637 	if (req.r != 0)
638 		return -EINVAL;
639 	return req.c ? clp_immediate_command(&req) : clp_normal_command(&req);
640 }
641 
642 static int clp_misc_release(struct inode *inode, struct file *filp)
643 {
644 	return 0;
645 }
646 
647 static const struct file_operations clp_misc_fops = {
648 	.owner = THIS_MODULE,
649 	.open = nonseekable_open,
650 	.release = clp_misc_release,
651 	.unlocked_ioctl = clp_misc_ioctl,
652 	.compat_ioctl = clp_misc_ioctl,
653 	.llseek = no_llseek,
654 };
655 
656 static struct miscdevice clp_misc_device = {
657 	.minor = MISC_DYNAMIC_MINOR,
658 	.name = "clp",
659 	.fops = &clp_misc_fops,
660 };
661 
662 static int __init clp_misc_init(void)
663 {
664 	return misc_register(&clp_misc_device);
665 }
666 
667 device_initcall(clp_misc_init);
668