xref: /linux/arch/s390/pci/pci_clp.c (revision 7fc2cd2e4b398c57c9cf961cfea05eadbf34c05c)
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 pr_fmt(fmt) "zpci: " fmt
10 
11 #include <linux/kernel.h>
12 #include <linux/miscdevice.h>
13 #include <linux/slab.h>
14 #include <linux/err.h>
15 #include <linux/delay.h>
16 #include <linux/pci.h>
17 #include <linux/uaccess.h>
18 #include <asm/asm-extable.h>
19 #include <asm/pci_debug.h>
20 #include <asm/pci_clp.h>
21 #include <asm/asm.h>
22 #include <asm/clp.h>
23 #include <uapi/asm/clp.h>
24 
25 #include "pci_bus.h"
26 
27 bool zpci_unique_uid;
28 
29 void update_uid_checking(bool new)
30 {
31 	if (zpci_unique_uid != new)
32 		zpci_dbg(3, "uid checking:%d\n", new);
33 
34 	zpci_unique_uid = new;
35 }
36 
37 static inline void zpci_err_clp(unsigned int rsp, int rc)
38 {
39 	struct {
40 		unsigned int rsp;
41 		int rc;
42 	} __packed data = {rsp, rc};
43 
44 	zpci_err_hex(&data, sizeof(data));
45 }
46 
47 /*
48  * Call Logical Processor with c=1, lps=0 and command 1
49  * to get the bit mask of installed logical processors
50  */
51 static inline int clp_get_ilp(unsigned long *ilp)
52 {
53 	unsigned long mask;
54 	int cc, exception;
55 
56 	exception = 1;
57 	asm_inline volatile (
58 		"	.insn	rrf,0xb9a00000,%[mask],%[cmd],8,0\n"
59 		"0:	lhi	%[exc],0\n"
60 		"1:\n"
61 		CC_IPM(cc)
62 		EX_TABLE(0b, 1b)
63 		: CC_OUT(cc, cc), [mask] "=d" (mask), [exc] "+d" (exception)
64 		: [cmd] "a" (1)
65 		: CC_CLOBBER);
66 	*ilp = mask;
67 	return exception ? 3 : CC_TRANSFORM(cc);
68 }
69 
70 /*
71  * Call Logical Processor with c=0, the give constant lps and an lpcb request.
72  */
73 static __always_inline int clp_req(void *data, unsigned int lps)
74 {
75 	struct { u8 _[CLP_BLK_SIZE]; } *req = data;
76 	int cc, exception;
77 	u64 ignored;
78 
79 	exception = 1;
80 	asm_inline volatile (
81 		"	.insn	rrf,0xb9a00000,%[ign],%[req],0,%[lps]\n"
82 		"0:	lhi	%[exc],0\n"
83 		"1:\n"
84 		CC_IPM(cc)
85 		EX_TABLE(0b, 1b)
86 		: CC_OUT(cc, cc), [ign] "=d" (ignored), "+m" (*req), [exc] "+d" (exception)
87 		: [req] "a" (req), [lps] "i" (lps)
88 		: CC_CLOBBER);
89 	return exception ? 3 : CC_TRANSFORM(cc);
90 }
91 
92 static void *clp_alloc_block(gfp_t gfp_mask)
93 {
94 	return (void *) __get_free_pages(gfp_mask, get_order(CLP_BLK_SIZE));
95 }
96 
97 static void clp_free_block(void *ptr)
98 {
99 	free_pages((unsigned long) ptr, get_order(CLP_BLK_SIZE));
100 }
101 
102 static void clp_store_query_pci_fngrp(struct zpci_dev *zdev,
103 				      struct clp_rsp_query_pci_grp *response)
104 {
105 	zdev->tlb_refresh = response->refresh;
106 	zdev->dma_mask = response->dasm;
107 	zdev->msi_addr = response->msia;
108 	zdev->max_msi = response->noi;
109 	zdev->fmb_update = response->mui;
110 	zdev->version = response->version;
111 	zdev->maxstbl = response->maxstbl;
112 	zdev->dtsm = response->dtsm;
113 	zdev->rtr_avail = response->rtr;
114 
115 	switch (response->version) {
116 	case 1:
117 		zdev->max_bus_speed = PCIE_SPEED_5_0GT;
118 		break;
119 	default:
120 		zdev->max_bus_speed = PCI_SPEED_UNKNOWN;
121 		break;
122 	}
123 }
124 
125 static int clp_query_pci_fngrp(struct zpci_dev *zdev, u8 pfgid)
126 {
127 	struct clp_req_rsp_query_pci_grp *rrb;
128 	int rc;
129 
130 	rrb = clp_alloc_block(GFP_KERNEL);
131 	if (!rrb)
132 		return -ENOMEM;
133 
134 	memset(rrb, 0, sizeof(*rrb));
135 	rrb->request.hdr.len = sizeof(rrb->request);
136 	rrb->request.hdr.cmd = CLP_QUERY_PCI_FNGRP;
137 	rrb->response.hdr.len = sizeof(rrb->response);
138 	rrb->request.pfgid = pfgid;
139 
140 	rc = clp_req(rrb, CLP_LPS_PCI);
141 	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK)
142 		clp_store_query_pci_fngrp(zdev, &rrb->response);
143 	else {
144 		zpci_err("Q PCI FGRP:\n");
145 		zpci_err_clp(rrb->response.hdr.rsp, rc);
146 		rc = -EIO;
147 	}
148 	clp_free_block(rrb);
149 	return rc;
150 }
151 
152 static int clp_store_query_pci_fn(struct zpci_dev *zdev,
153 				  struct clp_rsp_query_pci *response)
154 {
155 	int i;
156 
157 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
158 		zdev->bars[i].val = le32_to_cpu(response->bar[i]);
159 		zdev->bars[i].size = response->bar_size[i];
160 	}
161 	zdev->start_dma = response->sdma;
162 	zdev->end_dma = response->edma;
163 	zdev->pchid = response->pchid;
164 	zdev->pfgid = response->pfgid;
165 	zdev->pft = response->pft;
166 	zdev->vfn = response->vfn;
167 	zdev->port = response->port;
168 	zdev->fidparm = response->fidparm;
169 	zdev->uid = response->uid;
170 	zdev->fmb_length = sizeof(u32) * response->fmb_len;
171 	zdev->is_physfn = response->is_physfn;
172 	zdev->rid_available = response->rid_avail;
173 	if (zdev->rid_available)
174 		zdev->rid = response->rid;
175 	zdev->tid_avail = response->tid_avail;
176 	if (zdev->tid_avail)
177 		zdev->tid = response->tid;
178 
179 	memcpy(zdev->pfip, response->pfip, sizeof(zdev->pfip));
180 	if (response->util_str_avail) {
181 		memcpy(zdev->util_str, response->util_str,
182 		       sizeof(zdev->util_str));
183 		zdev->util_str_avail = 1;
184 	}
185 	zdev->mio_capable = response->mio_addr_avail;
186 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
187 		if (!(response->mio.valid & (1 << (PCI_STD_NUM_BARS - i - 1))))
188 			continue;
189 
190 		zdev->bars[i].mio_wb = (void __iomem *) response->mio.addr[i].wb;
191 		zdev->bars[i].mio_wt = (void __iomem *) response->mio.addr[i].wt;
192 	}
193 	return 0;
194 }
195 
196 int clp_query_pci_fn(struct zpci_dev *zdev)
197 {
198 	struct clp_req_rsp_query_pci *rrb;
199 	int rc;
200 
201 	rrb = clp_alloc_block(GFP_KERNEL);
202 	if (!rrb)
203 		return -ENOMEM;
204 
205 	memset(rrb, 0, sizeof(*rrb));
206 	rrb->request.hdr.len = sizeof(rrb->request);
207 	rrb->request.hdr.cmd = CLP_QUERY_PCI_FN;
208 	rrb->response.hdr.len = sizeof(rrb->response);
209 	rrb->request.fh = zdev->fh;
210 
211 	rc = clp_req(rrb, CLP_LPS_PCI);
212 	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) {
213 		rc = clp_store_query_pci_fn(zdev, &rrb->response);
214 		if (rc)
215 			goto out;
216 		rc = clp_query_pci_fngrp(zdev, rrb->response.pfgid);
217 	} else {
218 		zpci_err("Q PCI FN:\n");
219 		zpci_err_clp(rrb->response.hdr.rsp, rc);
220 		rc = -EIO;
221 	}
222 out:
223 	clp_free_block(rrb);
224 	return rc;
225 }
226 
227 /**
228  * clp_set_pci_fn() - Execute a command on a PCI function
229  * @zdev: Function that will be affected
230  * @fh: Out parameter for updated function handle
231  * @nr_dma_as: DMA address space number
232  * @command: The command code to execute
233  *
234  * Returns: 0 on success, < 0 for Linux errors (e.g. -ENOMEM), and
235  * > 0 for non-success platform responses
236  */
237 static int clp_set_pci_fn(struct zpci_dev *zdev, u32 *fh, u8 nr_dma_as, u8 command)
238 {
239 	struct clp_req_rsp_set_pci *rrb;
240 	int rc, retries = 100;
241 	u32 gisa = 0;
242 
243 	*fh = 0;
244 	rrb = clp_alloc_block(GFP_KERNEL);
245 	if (!rrb)
246 		return -ENOMEM;
247 
248 	if (command != CLP_SET_DISABLE_PCI_FN)
249 		gisa = zdev->gisa;
250 
251 	do {
252 		memset(rrb, 0, sizeof(*rrb));
253 		rrb->request.hdr.len = sizeof(rrb->request);
254 		rrb->request.hdr.cmd = CLP_SET_PCI_FN;
255 		rrb->response.hdr.len = sizeof(rrb->response);
256 		rrb->request.fh = zdev->fh;
257 		rrb->request.oc = command;
258 		rrb->request.ndas = nr_dma_as;
259 		rrb->request.gisa = gisa;
260 
261 		rc = clp_req(rrb, CLP_LPS_PCI);
262 		if (rrb->response.hdr.rsp == CLP_RC_SETPCIFN_BUSY) {
263 			retries--;
264 			if (retries < 0)
265 				break;
266 			msleep(20);
267 		}
268 	} while (rrb->response.hdr.rsp == CLP_RC_SETPCIFN_BUSY);
269 
270 	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) {
271 		*fh = rrb->response.fh;
272 	} else {
273 		zpci_err("Set PCI FN:\n");
274 		zpci_err_clp(rrb->response.hdr.rsp, rc);
275 		if (!rc)
276 			rc = rrb->response.hdr.rsp;
277 	}
278 	clp_free_block(rrb);
279 	return rc;
280 }
281 
282 int clp_setup_writeback_mio(void)
283 {
284 	struct clp_req_rsp_slpc_pci *rrb;
285 	u8  wb_bit_pos;
286 	int rc;
287 
288 	rrb = clp_alloc_block(GFP_KERNEL);
289 	if (!rrb)
290 		return -ENOMEM;
291 
292 	memset(rrb, 0, sizeof(*rrb));
293 	rrb->request.hdr.len = sizeof(rrb->request);
294 	rrb->request.hdr.cmd = CLP_SLPC;
295 	rrb->response.hdr.len = sizeof(rrb->response);
296 
297 	rc = clp_req(rrb, CLP_LPS_PCI);
298 	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) {
299 		if (rrb->response.vwb) {
300 			wb_bit_pos = rrb->response.mio_wb;
301 			set_bit_inv(wb_bit_pos, &mio_wb_bit_mask);
302 			zpci_dbg(3, "wb bit: %d\n", wb_bit_pos);
303 		} else {
304 			zpci_dbg(3, "wb bit: n.a.\n");
305 		}
306 
307 	} else {
308 		zpci_err("SLPC PCI:\n");
309 		zpci_err_clp(rrb->response.hdr.rsp, rc);
310 		rc = -EIO;
311 	}
312 	clp_free_block(rrb);
313 	return rc;
314 }
315 
316 int clp_enable_fh(struct zpci_dev *zdev, u32 *fh, u8 nr_dma_as)
317 {
318 	int rc;
319 
320 	rc = clp_set_pci_fn(zdev, fh, nr_dma_as, CLP_SET_ENABLE_PCI_FN);
321 	zpci_dbg(3, "ena fid:%x, fh:%x, rc:%d\n", zdev->fid, *fh, rc);
322 	if (!rc && zpci_use_mio(zdev)) {
323 		rc = clp_set_pci_fn(zdev, fh, nr_dma_as, CLP_SET_ENABLE_MIO);
324 		zpci_dbg(3, "ena mio fid:%x, fh:%x, rc:%d\n",
325 				zdev->fid, *fh, rc);
326 		if (rc)
327 			clp_disable_fh(zdev, fh);
328 	}
329 	return rc;
330 }
331 
332 int clp_disable_fh(struct zpci_dev *zdev, u32 *fh)
333 {
334 	int rc;
335 
336 	if (!zdev_enabled(zdev))
337 		return 0;
338 
339 	rc = clp_set_pci_fn(zdev, fh, 0, CLP_SET_DISABLE_PCI_FN);
340 	zpci_dbg(3, "dis fid:%x, fh:%x, rc:%d\n", zdev->fid, *fh, rc);
341 	return rc;
342 }
343 
344 static int clp_list_pci_req(struct clp_req_rsp_list_pci *rrb,
345 			    u64 *resume_token, int *nentries)
346 {
347 	int rc;
348 
349 	memset(rrb, 0, sizeof(*rrb));
350 	rrb->request.hdr.len = sizeof(rrb->request);
351 	rrb->request.hdr.cmd = CLP_LIST_PCI;
352 	/* store as many entries as possible */
353 	rrb->response.hdr.len = CLP_BLK_SIZE - LIST_PCI_HDR_LEN;
354 	rrb->request.resume_token = *resume_token;
355 
356 	/* Get PCI function handle list */
357 	rc = clp_req(rrb, CLP_LPS_PCI);
358 	if (rc || rrb->response.hdr.rsp != CLP_RC_OK) {
359 		zpci_err("List PCI FN:\n");
360 		zpci_err_clp(rrb->response.hdr.rsp, rc);
361 		return -EIO;
362 	}
363 
364 	update_uid_checking(rrb->response.uid_checking);
365 	WARN_ON_ONCE(rrb->response.entry_size !=
366 		sizeof(struct clp_fh_list_entry));
367 
368 	*nentries = (rrb->response.hdr.len - LIST_PCI_HDR_LEN) /
369 		rrb->response.entry_size;
370 	*resume_token = rrb->response.resume_token;
371 
372 	return rc;
373 }
374 
375 static int clp_list_pci(struct clp_req_rsp_list_pci *rrb, void *data,
376 			void (*cb)(struct clp_fh_list_entry *, void *))
377 {
378 	u64 resume_token = 0;
379 	int nentries, i, rc;
380 
381 	do {
382 		rc = clp_list_pci_req(rrb, &resume_token, &nentries);
383 		if (rc)
384 			return rc;
385 		for (i = 0; i < nentries; i++)
386 			cb(&rrb->response.fh_list[i], data);
387 	} while (resume_token);
388 
389 	return rc;
390 }
391 
392 static int clp_find_pci(struct clp_req_rsp_list_pci *rrb, u32 fid,
393 			struct clp_fh_list_entry *entry)
394 {
395 	struct clp_fh_list_entry *fh_list;
396 	u64 resume_token = 0;
397 	int nentries, i, rc;
398 
399 	do {
400 		rc = clp_list_pci_req(rrb, &resume_token, &nentries);
401 		if (rc)
402 			return rc;
403 		fh_list = rrb->response.fh_list;
404 		for (i = 0; i < nentries; i++) {
405 			if (fh_list[i].fid == fid) {
406 				*entry = fh_list[i];
407 				return 0;
408 			}
409 		}
410 	} while (resume_token);
411 
412 	return -ENODEV;
413 }
414 
415 static void __clp_add(struct clp_fh_list_entry *entry, void *data)
416 {
417 	struct list_head *scan_list = data;
418 	struct zpci_dev *zdev;
419 
420 	if (!entry->vendor_id)
421 		return;
422 
423 	zdev = get_zdev_by_fid(entry->fid);
424 	if (zdev) {
425 		zpci_zdev_put(zdev);
426 		return;
427 	}
428 	zdev = zpci_create_device(entry->fid, entry->fh, entry->config_state);
429 	if (IS_ERR(zdev))
430 		return;
431 	list_add_tail(&zdev->entry, scan_list);
432 }
433 
434 int clp_scan_pci_devices(struct list_head *scan_list)
435 {
436 	struct clp_req_rsp_list_pci *rrb;
437 	int rc;
438 
439 	rrb = clp_alloc_block(GFP_KERNEL);
440 	if (!rrb)
441 		return -ENOMEM;
442 
443 	rc = clp_list_pci(rrb, scan_list, __clp_add);
444 
445 	clp_free_block(rrb);
446 	return rc;
447 }
448 
449 /*
450  * Get the current function handle of the function matching @fid
451  */
452 int clp_refresh_fh(u32 fid, u32 *fh)
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_NOWAIT);
459 	if (!rrb)
460 		return -ENOMEM;
461 
462 	rc = clp_find_pci(rrb, fid, &entry);
463 	if (!rc)
464 		*fh = entry.fh;
465 
466 	clp_free_block(rrb);
467 	return rc;
468 }
469 
470 int clp_get_state(u32 fid, enum zpci_state *state)
471 {
472 	struct clp_req_rsp_list_pci *rrb;
473 	struct clp_fh_list_entry entry;
474 	int rc;
475 
476 	rrb = clp_alloc_block(GFP_ATOMIC);
477 	if (!rrb)
478 		return -ENOMEM;
479 
480 	rc = clp_find_pci(rrb, fid, &entry);
481 	if (!rc) {
482 		*state = entry.config_state;
483 	} else if (rc == -ENODEV) {
484 		*state = ZPCI_FN_STATE_RESERVED;
485 		rc = 0;
486 	}
487 
488 	clp_free_block(rrb);
489 	return rc;
490 }
491 
492 static int clp_base_slpc(struct clp_req *req, struct clp_req_rsp_slpc *lpcb)
493 {
494 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
495 
496 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
497 	    lpcb->response.hdr.len > limit)
498 		return -EINVAL;
499 	return clp_req(lpcb, CLP_LPS_BASE) ? -EOPNOTSUPP : 0;
500 }
501 
502 static int clp_base_command(struct clp_req *req, struct clp_req_hdr *lpcb)
503 {
504 	switch (lpcb->cmd) {
505 	case 0x0001: /* store logical-processor characteristics */
506 		return clp_base_slpc(req, (void *) lpcb);
507 	default:
508 		return -EINVAL;
509 	}
510 }
511 
512 static int clp_pci_slpc(struct clp_req *req, struct clp_req_rsp_slpc_pci *lpcb)
513 {
514 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
515 
516 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
517 	    lpcb->response.hdr.len > limit)
518 		return -EINVAL;
519 	return clp_req(lpcb, CLP_LPS_PCI) ? -EOPNOTSUPP : 0;
520 }
521 
522 static int clp_pci_list(struct clp_req *req, struct clp_req_rsp_list_pci *lpcb)
523 {
524 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
525 
526 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
527 	    lpcb->response.hdr.len > limit)
528 		return -EINVAL;
529 	if (lpcb->request.reserved2 != 0)
530 		return -EINVAL;
531 	return clp_req(lpcb, CLP_LPS_PCI) ? -EOPNOTSUPP : 0;
532 }
533 
534 static int clp_pci_query(struct clp_req *req,
535 			 struct clp_req_rsp_query_pci *lpcb)
536 {
537 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
538 
539 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
540 	    lpcb->response.hdr.len > limit)
541 		return -EINVAL;
542 	if (lpcb->request.reserved2 != 0 || lpcb->request.reserved3 != 0)
543 		return -EINVAL;
544 	return clp_req(lpcb, CLP_LPS_PCI) ? -EOPNOTSUPP : 0;
545 }
546 
547 static int clp_pci_query_grp(struct clp_req *req,
548 			     struct clp_req_rsp_query_pci_grp *lpcb)
549 {
550 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
551 
552 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
553 	    lpcb->response.hdr.len > limit)
554 		return -EINVAL;
555 	if (lpcb->request.reserved2 != 0 || lpcb->request.reserved3 != 0 ||
556 	    lpcb->request.reserved4 != 0)
557 		return -EINVAL;
558 	return clp_req(lpcb, CLP_LPS_PCI) ? -EOPNOTSUPP : 0;
559 }
560 
561 static int clp_pci_command(struct clp_req *req, struct clp_req_hdr *lpcb)
562 {
563 	switch (lpcb->cmd) {
564 	case 0x0001: /* store logical-processor characteristics */
565 		return clp_pci_slpc(req, (void *) lpcb);
566 	case 0x0002: /* list PCI functions */
567 		return clp_pci_list(req, (void *) lpcb);
568 	case 0x0003: /* query PCI function */
569 		return clp_pci_query(req, (void *) lpcb);
570 	case 0x0004: /* query PCI function group */
571 		return clp_pci_query_grp(req, (void *) lpcb);
572 	default:
573 		return -EINVAL;
574 	}
575 }
576 
577 static int clp_normal_command(struct clp_req *req)
578 {
579 	struct clp_req_hdr *lpcb;
580 	void __user *uptr;
581 	int rc;
582 
583 	rc = -EINVAL;
584 	if (req->lps != 0 && req->lps != 2)
585 		goto out;
586 
587 	rc = -ENOMEM;
588 	lpcb = clp_alloc_block(GFP_KERNEL);
589 	if (!lpcb)
590 		goto out;
591 
592 	rc = -EFAULT;
593 	uptr = (void __force __user *)(unsigned long) req->data_p;
594 	if (copy_from_user(lpcb, uptr, PAGE_SIZE) != 0)
595 		goto out_free;
596 
597 	rc = -EINVAL;
598 	if (lpcb->fmt != 0 || lpcb->reserved1 != 0 || lpcb->reserved2 != 0)
599 		goto out_free;
600 
601 	switch (req->lps) {
602 	case 0:
603 		rc = clp_base_command(req, lpcb);
604 		break;
605 	case 2:
606 		rc = clp_pci_command(req, lpcb);
607 		break;
608 	}
609 	if (rc)
610 		goto out_free;
611 
612 	rc = -EFAULT;
613 	if (copy_to_user(uptr, lpcb, PAGE_SIZE) != 0)
614 		goto out_free;
615 
616 	rc = 0;
617 
618 out_free:
619 	clp_free_block(lpcb);
620 out:
621 	return rc;
622 }
623 
624 static int clp_immediate_command(struct clp_req *req)
625 {
626 	void __user *uptr;
627 	unsigned long ilp;
628 	int exists;
629 
630 	if (req->cmd > 1 || clp_get_ilp(&ilp) != 0)
631 		return -EINVAL;
632 
633 	uptr = (void __force __user *)(unsigned long) req->data_p;
634 	if (req->cmd == 0) {
635 		/* Command code 0: test for a specific processor */
636 		exists = test_bit_inv(req->lps, &ilp);
637 		return put_user(exists, (int __user *) uptr);
638 	}
639 	/* Command code 1: return bit mask of installed processors */
640 	return put_user(ilp, (unsigned long __user *) uptr);
641 }
642 
643 static long clp_misc_ioctl(struct file *filp, unsigned int cmd,
644 			   unsigned long arg)
645 {
646 	struct clp_req req;
647 	void __user *argp;
648 
649 	if (cmd != CLP_SYNC)
650 		return -EINVAL;
651 
652 	argp = (void __user *)arg;
653 	if (copy_from_user(&req, argp, sizeof(req)))
654 		return -EFAULT;
655 	if (req.r != 0)
656 		return -EINVAL;
657 	return req.c ? clp_immediate_command(&req) : clp_normal_command(&req);
658 }
659 
660 static int clp_misc_release(struct inode *inode, struct file *filp)
661 {
662 	return 0;
663 }
664 
665 static const struct file_operations clp_misc_fops = {
666 	.owner = THIS_MODULE,
667 	.open = nonseekable_open,
668 	.release = clp_misc_release,
669 	.unlocked_ioctl = clp_misc_ioctl,
670 };
671 
672 static struct miscdevice clp_misc_device = {
673 	.minor = MISC_DYNAMIC_MINOR,
674 	.name = "clp",
675 	.fops = &clp_misc_fops,
676 };
677 
678 builtin_misc_device(clp_misc_device);
679