xref: /linux/arch/s390/pci/pci_clp.c (revision 0d3b051adbb72ed81956447d0d1e54d5943ee6f5)
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 static int clp_query_pci_fn(struct zpci_dev *zdev, u32 fh)
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 = 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 int clp_add_pci_device(u32 fid, u32 fh, int configured)
216 {
217 	struct zpci_dev *zdev;
218 	int rc = -ENOMEM;
219 
220 	zpci_dbg(3, "add fid:%x, fh:%x, c:%d\n", fid, fh, configured);
221 	zdev = kzalloc(sizeof(*zdev), GFP_KERNEL);
222 	if (!zdev)
223 		goto error;
224 
225 	zdev->fh = fh;
226 	zdev->fid = fid;
227 
228 	/* Query function properties and update zdev */
229 	rc = clp_query_pci_fn(zdev, fh);
230 	if (rc)
231 		goto error;
232 
233 	if (configured)
234 		zdev->state = ZPCI_FN_STATE_CONFIGURED;
235 	else
236 		zdev->state = ZPCI_FN_STATE_STANDBY;
237 
238 	rc = zpci_create_device(zdev);
239 	if (rc)
240 		goto error;
241 	return 0;
242 
243 error:
244 	zpci_dbg(0, "add fid:%x, rc:%d\n", fid, rc);
245 	kfree(zdev);
246 	return rc;
247 }
248 
249 static int clp_refresh_fh(u32 fid);
250 /*
251  * Enable/Disable a given PCI function and update its function handle if
252  * necessary
253  */
254 static int clp_set_pci_fn(struct zpci_dev *zdev, u8 nr_dma_as, u8 command)
255 {
256 	struct clp_req_rsp_set_pci *rrb;
257 	int rc, retries = 100;
258 	u32 fid = zdev->fid;
259 
260 	rrb = clp_alloc_block(GFP_KERNEL);
261 	if (!rrb)
262 		return -ENOMEM;
263 
264 	do {
265 		memset(rrb, 0, sizeof(*rrb));
266 		rrb->request.hdr.len = sizeof(rrb->request);
267 		rrb->request.hdr.cmd = CLP_SET_PCI_FN;
268 		rrb->response.hdr.len = sizeof(rrb->response);
269 		rrb->request.fh = zdev->fh;
270 		rrb->request.oc = command;
271 		rrb->request.ndas = nr_dma_as;
272 
273 		rc = clp_req(rrb, CLP_LPS_PCI);
274 		if (rrb->response.hdr.rsp == CLP_RC_SETPCIFN_BUSY) {
275 			retries--;
276 			if (retries < 0)
277 				break;
278 			msleep(20);
279 		}
280 	} while (rrb->response.hdr.rsp == CLP_RC_SETPCIFN_BUSY);
281 
282 	if (rc || rrb->response.hdr.rsp != CLP_RC_OK) {
283 		zpci_err("Set PCI FN:\n");
284 		zpci_err_clp(rrb->response.hdr.rsp, rc);
285 	}
286 
287 	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) {
288 		zdev->fh = rrb->response.fh;
289 	} else if (!rc && rrb->response.hdr.rsp == CLP_RC_SETPCIFN_ALRDY &&
290 			rrb->response.fh == 0) {
291 		/* Function is already in desired state - update handle */
292 		rc = clp_refresh_fh(fid);
293 	}
294 	clp_free_block(rrb);
295 	return rc;
296 }
297 
298 int clp_setup_writeback_mio(void)
299 {
300 	struct clp_req_rsp_slpc_pci *rrb;
301 	u8  wb_bit_pos;
302 	int rc;
303 
304 	rrb = clp_alloc_block(GFP_KERNEL);
305 	if (!rrb)
306 		return -ENOMEM;
307 
308 	memset(rrb, 0, sizeof(*rrb));
309 	rrb->request.hdr.len = sizeof(rrb->request);
310 	rrb->request.hdr.cmd = CLP_SLPC;
311 	rrb->response.hdr.len = sizeof(rrb->response);
312 
313 	rc = clp_req(rrb, CLP_LPS_PCI);
314 	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) {
315 		if (rrb->response.vwb) {
316 			wb_bit_pos = rrb->response.mio_wb;
317 			set_bit_inv(wb_bit_pos, &mio_wb_bit_mask);
318 			zpci_dbg(3, "wb bit: %d\n", wb_bit_pos);
319 		} else {
320 			zpci_dbg(3, "wb bit: n.a.\n");
321 		}
322 
323 	} else {
324 		zpci_err("SLPC PCI:\n");
325 		zpci_err_clp(rrb->response.hdr.rsp, rc);
326 		rc = -EIO;
327 	}
328 	clp_free_block(rrb);
329 	return rc;
330 }
331 
332 int clp_enable_fh(struct zpci_dev *zdev, u8 nr_dma_as)
333 {
334 	int rc;
335 
336 	rc = clp_set_pci_fn(zdev, nr_dma_as, CLP_SET_ENABLE_PCI_FN);
337 	zpci_dbg(3, "ena fid:%x, fh:%x, rc:%d\n", zdev->fid, zdev->fh, rc);
338 	if (rc)
339 		goto out;
340 
341 	if (zpci_use_mio(zdev)) {
342 		rc = clp_set_pci_fn(zdev, nr_dma_as, CLP_SET_ENABLE_MIO);
343 		zpci_dbg(3, "ena mio fid:%x, fh:%x, rc:%d\n",
344 				zdev->fid, zdev->fh, rc);
345 		if (rc)
346 			clp_disable_fh(zdev);
347 	}
348 out:
349 	return rc;
350 }
351 
352 int clp_disable_fh(struct zpci_dev *zdev)
353 {
354 	int rc;
355 
356 	if (!zdev_enabled(zdev))
357 		return 0;
358 
359 	rc = clp_set_pci_fn(zdev, 0, CLP_SET_DISABLE_PCI_FN);
360 	zpci_dbg(3, "dis fid:%x, fh:%x, rc:%d\n", zdev->fid, zdev->fh, rc);
361 	return rc;
362 }
363 
364 static int clp_list_pci(struct clp_req_rsp_list_pci *rrb, void *data,
365 			void (*cb)(struct clp_fh_list_entry *, void *))
366 {
367 	u64 resume_token = 0;
368 	int entries, i, rc;
369 
370 	do {
371 		memset(rrb, 0, sizeof(*rrb));
372 		rrb->request.hdr.len = sizeof(rrb->request);
373 		rrb->request.hdr.cmd = CLP_LIST_PCI;
374 		/* store as many entries as possible */
375 		rrb->response.hdr.len = CLP_BLK_SIZE - LIST_PCI_HDR_LEN;
376 		rrb->request.resume_token = resume_token;
377 
378 		/* Get PCI function handle list */
379 		rc = clp_req(rrb, CLP_LPS_PCI);
380 		if (rc || rrb->response.hdr.rsp != CLP_RC_OK) {
381 			zpci_err("List PCI FN:\n");
382 			zpci_err_clp(rrb->response.hdr.rsp, rc);
383 			rc = -EIO;
384 			goto out;
385 		}
386 
387 		update_uid_checking(rrb->response.uid_checking);
388 		WARN_ON_ONCE(rrb->response.entry_size !=
389 			sizeof(struct clp_fh_list_entry));
390 
391 		entries = (rrb->response.hdr.len - LIST_PCI_HDR_LEN) /
392 			rrb->response.entry_size;
393 
394 		resume_token = rrb->response.resume_token;
395 		for (i = 0; i < entries; i++)
396 			cb(&rrb->response.fh_list[i], data);
397 	} while (resume_token);
398 out:
399 	return rc;
400 }
401 
402 static void __clp_add(struct clp_fh_list_entry *entry, void *data)
403 {
404 	struct zpci_dev *zdev;
405 
406 	if (!entry->vendor_id)
407 		return;
408 
409 	zdev = get_zdev_by_fid(entry->fid);
410 	if (!zdev)
411 		clp_add_pci_device(entry->fid, entry->fh, entry->config_state);
412 }
413 
414 int clp_scan_pci_devices(void)
415 {
416 	struct clp_req_rsp_list_pci *rrb;
417 	int rc;
418 
419 	rrb = clp_alloc_block(GFP_KERNEL);
420 	if (!rrb)
421 		return -ENOMEM;
422 
423 	rc = clp_list_pci(rrb, NULL, __clp_add);
424 
425 	clp_free_block(rrb);
426 	return rc;
427 }
428 
429 static void __clp_refresh_fh(struct clp_fh_list_entry *entry, void *data)
430 {
431 	struct zpci_dev *zdev;
432 	u32 fid = *((u32 *)data);
433 
434 	if (!entry->vendor_id || fid != entry->fid)
435 		return;
436 
437 	zdev = get_zdev_by_fid(fid);
438 	if (!zdev)
439 		return;
440 
441 	zdev->fh = entry->fh;
442 }
443 
444 /*
445  * Refresh the function handle of the function matching @fid
446  */
447 static int clp_refresh_fh(u32 fid)
448 {
449 	struct clp_req_rsp_list_pci *rrb;
450 	int rc;
451 
452 	rrb = clp_alloc_block(GFP_NOWAIT);
453 	if (!rrb)
454 		return -ENOMEM;
455 
456 	rc = clp_list_pci(rrb, &fid, __clp_refresh_fh);
457 
458 	clp_free_block(rrb);
459 	return rc;
460 }
461 
462 struct clp_state_data {
463 	u32 fid;
464 	enum zpci_state state;
465 };
466 
467 static void __clp_get_state(struct clp_fh_list_entry *entry, void *data)
468 {
469 	struct clp_state_data *sd = data;
470 
471 	if (entry->fid != sd->fid)
472 		return;
473 
474 	sd->state = entry->config_state;
475 }
476 
477 int clp_get_state(u32 fid, enum zpci_state *state)
478 {
479 	struct clp_req_rsp_list_pci *rrb;
480 	struct clp_state_data sd = {fid, ZPCI_FN_STATE_RESERVED};
481 	int rc;
482 
483 	rrb = clp_alloc_block(GFP_ATOMIC);
484 	if (!rrb)
485 		return -ENOMEM;
486 
487 	rc = clp_list_pci(rrb, &sd, __clp_get_state);
488 	if (!rc)
489 		*state = sd.state;
490 
491 	clp_free_block(rrb);
492 	return rc;
493 }
494 
495 static int clp_base_slpc(struct clp_req *req, struct clp_req_rsp_slpc *lpcb)
496 {
497 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
498 
499 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
500 	    lpcb->response.hdr.len > limit)
501 		return -EINVAL;
502 	return clp_req(lpcb, CLP_LPS_BASE) ? -EOPNOTSUPP : 0;
503 }
504 
505 static int clp_base_command(struct clp_req *req, struct clp_req_hdr *lpcb)
506 {
507 	switch (lpcb->cmd) {
508 	case 0x0001: /* store logical-processor characteristics */
509 		return clp_base_slpc(req, (void *) lpcb);
510 	default:
511 		return -EINVAL;
512 	}
513 }
514 
515 static int clp_pci_slpc(struct clp_req *req, struct clp_req_rsp_slpc_pci *lpcb)
516 {
517 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
518 
519 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
520 	    lpcb->response.hdr.len > limit)
521 		return -EINVAL;
522 	return clp_req(lpcb, CLP_LPS_PCI) ? -EOPNOTSUPP : 0;
523 }
524 
525 static int clp_pci_list(struct clp_req *req, struct clp_req_rsp_list_pci *lpcb)
526 {
527 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
528 
529 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
530 	    lpcb->response.hdr.len > limit)
531 		return -EINVAL;
532 	if (lpcb->request.reserved2 != 0)
533 		return -EINVAL;
534 	return clp_req(lpcb, CLP_LPS_PCI) ? -EOPNOTSUPP : 0;
535 }
536 
537 static int clp_pci_query(struct clp_req *req,
538 			 struct clp_req_rsp_query_pci *lpcb)
539 {
540 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
541 
542 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
543 	    lpcb->response.hdr.len > limit)
544 		return -EINVAL;
545 	if (lpcb->request.reserved2 != 0 || lpcb->request.reserved3 != 0)
546 		return -EINVAL;
547 	return clp_req(lpcb, CLP_LPS_PCI) ? -EOPNOTSUPP : 0;
548 }
549 
550 static int clp_pci_query_grp(struct clp_req *req,
551 			     struct clp_req_rsp_query_pci_grp *lpcb)
552 {
553 	unsigned long limit = PAGE_SIZE - sizeof(lpcb->request);
554 
555 	if (lpcb->request.hdr.len != sizeof(lpcb->request) ||
556 	    lpcb->response.hdr.len > limit)
557 		return -EINVAL;
558 	if (lpcb->request.reserved2 != 0 || lpcb->request.reserved3 != 0 ||
559 	    lpcb->request.reserved4 != 0)
560 		return -EINVAL;
561 	return clp_req(lpcb, CLP_LPS_PCI) ? -EOPNOTSUPP : 0;
562 }
563 
564 static int clp_pci_command(struct clp_req *req, struct clp_req_hdr *lpcb)
565 {
566 	switch (lpcb->cmd) {
567 	case 0x0001: /* store logical-processor characteristics */
568 		return clp_pci_slpc(req, (void *) lpcb);
569 	case 0x0002: /* list PCI functions */
570 		return clp_pci_list(req, (void *) lpcb);
571 	case 0x0003: /* query PCI function */
572 		return clp_pci_query(req, (void *) lpcb);
573 	case 0x0004: /* query PCI function group */
574 		return clp_pci_query_grp(req, (void *) lpcb);
575 	default:
576 		return -EINVAL;
577 	}
578 }
579 
580 static int clp_normal_command(struct clp_req *req)
581 {
582 	struct clp_req_hdr *lpcb;
583 	void __user *uptr;
584 	int rc;
585 
586 	rc = -EINVAL;
587 	if (req->lps != 0 && req->lps != 2)
588 		goto out;
589 
590 	rc = -ENOMEM;
591 	lpcb = clp_alloc_block(GFP_KERNEL);
592 	if (!lpcb)
593 		goto out;
594 
595 	rc = -EFAULT;
596 	uptr = (void __force __user *)(unsigned long) req->data_p;
597 	if (copy_from_user(lpcb, uptr, PAGE_SIZE) != 0)
598 		goto out_free;
599 
600 	rc = -EINVAL;
601 	if (lpcb->fmt != 0 || lpcb->reserved1 != 0 || lpcb->reserved2 != 0)
602 		goto out_free;
603 
604 	switch (req->lps) {
605 	case 0:
606 		rc = clp_base_command(req, lpcb);
607 		break;
608 	case 2:
609 		rc = clp_pci_command(req, lpcb);
610 		break;
611 	}
612 	if (rc)
613 		goto out_free;
614 
615 	rc = -EFAULT;
616 	if (copy_to_user(uptr, lpcb, PAGE_SIZE) != 0)
617 		goto out_free;
618 
619 	rc = 0;
620 
621 out_free:
622 	clp_free_block(lpcb);
623 out:
624 	return rc;
625 }
626 
627 static int clp_immediate_command(struct clp_req *req)
628 {
629 	void __user *uptr;
630 	unsigned long ilp;
631 	int exists;
632 
633 	if (req->cmd > 1 || clp_get_ilp(&ilp) != 0)
634 		return -EINVAL;
635 
636 	uptr = (void __force __user *)(unsigned long) req->data_p;
637 	if (req->cmd == 0) {
638 		/* Command code 0: test for a specific processor */
639 		exists = test_bit_inv(req->lps, &ilp);
640 		return put_user(exists, (int __user *) uptr);
641 	}
642 	/* Command code 1: return bit mask of installed processors */
643 	return put_user(ilp, (unsigned long __user *) uptr);
644 }
645 
646 static long clp_misc_ioctl(struct file *filp, unsigned int cmd,
647 			   unsigned long arg)
648 {
649 	struct clp_req req;
650 	void __user *argp;
651 
652 	if (cmd != CLP_SYNC)
653 		return -EINVAL;
654 
655 	argp = is_compat_task() ? compat_ptr(arg) : (void __user *) arg;
656 	if (copy_from_user(&req, argp, sizeof(req)))
657 		return -EFAULT;
658 	if (req.r != 0)
659 		return -EINVAL;
660 	return req.c ? clp_immediate_command(&req) : clp_normal_command(&req);
661 }
662 
663 static int clp_misc_release(struct inode *inode, struct file *filp)
664 {
665 	return 0;
666 }
667 
668 static const struct file_operations clp_misc_fops = {
669 	.owner = THIS_MODULE,
670 	.open = nonseekable_open,
671 	.release = clp_misc_release,
672 	.unlocked_ioctl = clp_misc_ioctl,
673 	.compat_ioctl = clp_misc_ioctl,
674 	.llseek = no_llseek,
675 };
676 
677 static struct miscdevice clp_misc_device = {
678 	.minor = MISC_DYNAMIC_MINOR,
679 	.name = "clp",
680 	.fops = &clp_misc_fops,
681 };
682 
683 static int __init clp_misc_init(void)
684 {
685 	return misc_register(&clp_misc_device);
686 }
687 
688 device_initcall(clp_misc_init);
689