xref: /linux/drivers/misc/hpilo.c (revision c16ce856e422e73a54c41131e0332de1afe09b8b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver for the HP iLO management processor.
4  *
5  * Copyright (C) 2008 Hewlett-Packard Development Company, L.P.
6  *	David Altobelli <david.altobelli@hpe.com>
7  */
8 #include <linux/kernel.h>
9 #include <linux/types.h>
10 #include <linux/module.h>
11 #include <linux/fs.h>
12 #include <linux/pci.h>
13 #include <linux/interrupt.h>
14 #include <linux/ioport.h>
15 #include <linux/device.h>
16 #include <linux/file.h>
17 #include <linux/cdev.h>
18 #include <linux/sched.h>
19 #include <linux/spinlock.h>
20 #include <linux/delay.h>
21 #include <linux/uaccess.h>
22 #include <linux/io.h>
23 #include <linux/wait.h>
24 #include <linux/poll.h>
25 #include <linux/slab.h>
26 #include "hpilo.h"
27 
28 static const struct class ilo_class = {
29 	.name = "iLO",
30 };
31 static unsigned int ilo_major;
32 static unsigned int max_ccb = 16;
33 static char ilo_hwdev[MAX_ILO_DEV];
34 static const struct pci_device_id ilo_blacklist[] = {
35 	/* auxiliary iLO */
36 	{PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3307, PCI_VENDOR_ID_HP, 0x1979)},
37 	/* CL */
38 	{PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3307, PCI_VENDOR_ID_HP_3PAR, 0x0289)},
39 	{}
40 };
41 
42 static inline int get_entry_id(int entry)
43 {
44 	return (entry & ENTRY_MASK_DESCRIPTOR) >> ENTRY_BITPOS_DESCRIPTOR;
45 }
46 
47 static inline int get_entry_len(int entry)
48 {
49 	return ((entry & ENTRY_MASK_QWORDS) >> ENTRY_BITPOS_QWORDS) << 3;
50 }
51 
52 static inline int mk_entry(int id, int len)
53 {
54 	int qlen = len & 7 ? (len >> 3) + 1 : len >> 3;
55 	return id << ENTRY_BITPOS_DESCRIPTOR | qlen << ENTRY_BITPOS_QWORDS;
56 }
57 
58 static inline int desc_mem_sz(int nr_entry)
59 {
60 	return nr_entry << L2_QENTRY_SZ;
61 }
62 
63 /*
64  * FIFO queues, shared with hardware.
65  *
66  * If a queue has empty slots, an entry is added to the queue tail,
67  * and that entry is marked as occupied.
68  * Entries can be dequeued from the head of the list, when the device
69  * has marked the entry as consumed.
70  *
71  * Returns true on successful queue/dequeue, false on failure.
72  */
73 static int fifo_enqueue(struct ilo_hwinfo *hw, char *fifobar, int entry)
74 {
75 	struct fifo *fifo_q = FIFOBARTOHANDLE(fifobar);
76 	unsigned long flags;
77 	int ret = 0;
78 
79 	spin_lock_irqsave(&hw->fifo_lock, flags);
80 	if (!(fifo_q->fifobar[(fifo_q->tail + 1) & fifo_q->imask]
81 	      & ENTRY_MASK_O)) {
82 		fifo_q->fifobar[fifo_q->tail & fifo_q->imask] |=
83 				(entry & ENTRY_MASK_NOSTATE) | fifo_q->merge;
84 		fifo_q->tail += 1;
85 		ret = 1;
86 	}
87 	spin_unlock_irqrestore(&hw->fifo_lock, flags);
88 
89 	return ret;
90 }
91 
92 static int fifo_dequeue(struct ilo_hwinfo *hw, char *fifobar, int *entry)
93 {
94 	struct fifo *fifo_q = FIFOBARTOHANDLE(fifobar);
95 	unsigned long flags;
96 	int ret = 0;
97 	u64 c;
98 
99 	spin_lock_irqsave(&hw->fifo_lock, flags);
100 	c = fifo_q->fifobar[fifo_q->head & fifo_q->imask];
101 	if (c & ENTRY_MASK_C) {
102 		if (entry)
103 			*entry = c & ENTRY_MASK_NOSTATE;
104 
105 		fifo_q->fifobar[fifo_q->head & fifo_q->imask] =
106 							(c | ENTRY_MASK) + 1;
107 		fifo_q->head += 1;
108 		ret = 1;
109 	}
110 	spin_unlock_irqrestore(&hw->fifo_lock, flags);
111 
112 	return ret;
113 }
114 
115 static int fifo_check_recv(struct ilo_hwinfo *hw, char *fifobar)
116 {
117 	struct fifo *fifo_q = FIFOBARTOHANDLE(fifobar);
118 	unsigned long flags;
119 	int ret = 0;
120 	u64 c;
121 
122 	spin_lock_irqsave(&hw->fifo_lock, flags);
123 	c = fifo_q->fifobar[fifo_q->head & fifo_q->imask];
124 	if (c & ENTRY_MASK_C)
125 		ret = 1;
126 	spin_unlock_irqrestore(&hw->fifo_lock, flags);
127 
128 	return ret;
129 }
130 
131 static int ilo_pkt_enqueue(struct ilo_hwinfo *hw, struct ccb *ccb,
132 			   int dir, int id, int len)
133 {
134 	char *fifobar;
135 	int entry;
136 
137 	if (dir == SENDQ)
138 		fifobar = ccb->ccb_u1.send_fifobar;
139 	else
140 		fifobar = ccb->ccb_u3.recv_fifobar;
141 
142 	entry = mk_entry(id, len);
143 	return fifo_enqueue(hw, fifobar, entry);
144 }
145 
146 static int ilo_pkt_dequeue(struct ilo_hwinfo *hw, struct ccb *ccb,
147 			   int dir, int *id, int *len, void **pkt)
148 {
149 	char *fifobar, *desc;
150 	int entry = 0, pkt_id = 0;
151 	int ret;
152 
153 	if (dir == SENDQ) {
154 		fifobar = ccb->ccb_u1.send_fifobar;
155 		desc = ccb->ccb_u2.send_desc;
156 	} else {
157 		fifobar = ccb->ccb_u3.recv_fifobar;
158 		desc = ccb->ccb_u4.recv_desc;
159 	}
160 
161 	ret = fifo_dequeue(hw, fifobar, &entry);
162 	if (ret) {
163 		int pkt_len;
164 
165 		pkt_id = get_entry_id(entry);
166 		pkt_len = get_entry_len(entry);
167 		if (pkt_id >= NR_QENTRY || pkt_len > desc_mem_sz(1))
168 			return 0;
169 		if (id)
170 			*id = pkt_id;
171 		if (len)
172 			*len = pkt_len;
173 		if (pkt)
174 			*pkt = (void *)(desc + desc_mem_sz(pkt_id));
175 	}
176 
177 	return ret;
178 }
179 
180 static int ilo_pkt_recv(struct ilo_hwinfo *hw, struct ccb *ccb)
181 {
182 	char *fifobar = ccb->ccb_u3.recv_fifobar;
183 
184 	return fifo_check_recv(hw, fifobar);
185 }
186 
187 static inline void doorbell_set(struct ccb *ccb)
188 {
189 	iowrite8(1, ccb->ccb_u5.db_base);
190 }
191 
192 static inline void doorbell_clr(struct ccb *ccb)
193 {
194 	iowrite8(2, ccb->ccb_u5.db_base);
195 }
196 
197 static inline int ctrl_set(int l2sz, int idxmask, int desclim)
198 {
199 	int active = 0, go = 1;
200 	return l2sz << CTRL_BITPOS_L2SZ |
201 	       idxmask << CTRL_BITPOS_FIFOINDEXMASK |
202 	       desclim << CTRL_BITPOS_DESCLIMIT |
203 	       active << CTRL_BITPOS_A |
204 	       go << CTRL_BITPOS_G;
205 }
206 
207 static void ctrl_setup(struct ccb *ccb, int nr_desc, int l2desc_sz)
208 {
209 	/* for simplicity, use the same parameters for send and recv ctrls */
210 	ccb->send_ctrl = ctrl_set(l2desc_sz, nr_desc-1, nr_desc-1);
211 	ccb->recv_ctrl = ctrl_set(l2desc_sz, nr_desc-1, nr_desc-1);
212 }
213 
214 static inline int fifo_sz(int nr_entry)
215 {
216 	/* size of a fifo is determined by the number of entries it contains */
217 	return nr_entry * sizeof(u64) + FIFOHANDLESIZE;
218 }
219 
220 static void fifo_setup(void *base_addr, int nr_entry)
221 {
222 	struct fifo *fifo_q = base_addr;
223 	int i;
224 
225 	/* set up an empty fifo */
226 	fifo_q->head = 0;
227 	fifo_q->tail = 0;
228 	fifo_q->reset = 0;
229 	fifo_q->nrents = nr_entry;
230 	fifo_q->imask = nr_entry - 1;
231 	fifo_q->merge = ENTRY_MASK_O;
232 
233 	for (i = 0; i < nr_entry; i++)
234 		fifo_q->fifobar[i] = 0;
235 }
236 
237 static void ilo_ccb_close(struct pci_dev *pdev, struct ccb_data *data)
238 {
239 	struct ccb *driver_ccb = &data->driver_ccb;
240 	struct ccb __iomem *device_ccb = data->mapped_ccb;
241 	int retries;
242 
243 	/* complicated dance to tell the hw we are stopping */
244 	doorbell_clr(driver_ccb);
245 	iowrite32(ioread32(&device_ccb->send_ctrl) & ~(1 << CTRL_BITPOS_G),
246 		  &device_ccb->send_ctrl);
247 	iowrite32(ioread32(&device_ccb->recv_ctrl) & ~(1 << CTRL_BITPOS_G),
248 		  &device_ccb->recv_ctrl);
249 
250 	/* give iLO some time to process stop request */
251 	for (retries = MAX_WAIT; retries > 0; retries--) {
252 		doorbell_set(driver_ccb);
253 		udelay(WAIT_TIME);
254 		if (!(ioread32(&device_ccb->send_ctrl) & (1 << CTRL_BITPOS_A))
255 		    &&
256 		    !(ioread32(&device_ccb->recv_ctrl) & (1 << CTRL_BITPOS_A)))
257 			break;
258 	}
259 	if (retries == 0)
260 		dev_err(&pdev->dev, "Closing, but controller still active\n");
261 
262 	/* clear the hw ccb */
263 	memset_io(device_ccb, 0, sizeof(struct ccb));
264 
265 	/* free resources used to back send/recv queues */
266 	dma_free_coherent(&pdev->dev, data->dma_size, data->dma_va,
267 			  data->dma_pa);
268 }
269 
270 static int ilo_ccb_setup(struct ilo_hwinfo *hw, struct ccb_data *data, int slot)
271 {
272 	char *dma_va;
273 	dma_addr_t dma_pa;
274 	struct ccb *driver_ccb, *ilo_ccb;
275 
276 	driver_ccb = &data->driver_ccb;
277 	ilo_ccb = &data->ilo_ccb;
278 
279 	data->dma_size = 2 * fifo_sz(NR_QENTRY) +
280 			 2 * desc_mem_sz(NR_QENTRY) +
281 			 ILO_START_ALIGN + ILO_CACHE_SZ;
282 
283 	data->dma_va = dma_alloc_coherent(&hw->ilo_dev->dev, data->dma_size,
284 					  &data->dma_pa, GFP_ATOMIC);
285 	if (!data->dma_va)
286 		return -ENOMEM;
287 
288 	dma_va = (char *)data->dma_va;
289 	dma_pa = data->dma_pa;
290 
291 	dma_va = (char *)roundup((unsigned long)dma_va, ILO_START_ALIGN);
292 	dma_pa = roundup(dma_pa, ILO_START_ALIGN);
293 
294 	/*
295 	 * Create two ccb's, one with virt addrs, one with phys addrs.
296 	 * Copy the phys addr ccb to device shared mem.
297 	 */
298 	ctrl_setup(driver_ccb, NR_QENTRY, L2_QENTRY_SZ);
299 	ctrl_setup(ilo_ccb, NR_QENTRY, L2_QENTRY_SZ);
300 
301 	fifo_setup(dma_va, NR_QENTRY);
302 	driver_ccb->ccb_u1.send_fifobar = dma_va + FIFOHANDLESIZE;
303 	ilo_ccb->ccb_u1.send_fifobar_pa = dma_pa + FIFOHANDLESIZE;
304 	dma_va += fifo_sz(NR_QENTRY);
305 	dma_pa += fifo_sz(NR_QENTRY);
306 
307 	dma_va = (char *)roundup((unsigned long)dma_va, ILO_CACHE_SZ);
308 	dma_pa = roundup(dma_pa, ILO_CACHE_SZ);
309 
310 	fifo_setup(dma_va, NR_QENTRY);
311 	driver_ccb->ccb_u3.recv_fifobar = dma_va + FIFOHANDLESIZE;
312 	ilo_ccb->ccb_u3.recv_fifobar_pa = dma_pa + FIFOHANDLESIZE;
313 	dma_va += fifo_sz(NR_QENTRY);
314 	dma_pa += fifo_sz(NR_QENTRY);
315 
316 	driver_ccb->ccb_u2.send_desc = dma_va;
317 	ilo_ccb->ccb_u2.send_desc_pa = dma_pa;
318 	dma_pa += desc_mem_sz(NR_QENTRY);
319 	dma_va += desc_mem_sz(NR_QENTRY);
320 
321 	driver_ccb->ccb_u4.recv_desc = dma_va;
322 	ilo_ccb->ccb_u4.recv_desc_pa = dma_pa;
323 
324 	driver_ccb->channel = slot;
325 	ilo_ccb->channel = slot;
326 
327 	driver_ccb->ccb_u5.db_base = hw->db_vaddr + (slot << L2_DB_SIZE);
328 	ilo_ccb->ccb_u5.db_base = NULL; /* hw ccb's doorbell is not used */
329 
330 	return 0;
331 }
332 
333 static void ilo_ccb_open(struct ilo_hwinfo *hw, struct ccb_data *data, int slot)
334 {
335 	int pkt_id, pkt_sz;
336 	struct ccb *driver_ccb = &data->driver_ccb;
337 
338 	/* copy the ccb with physical addrs to device memory */
339 	data->mapped_ccb = (struct ccb __iomem *)
340 				(hw->ram_vaddr + (slot * ILOHW_CCB_SZ));
341 	memcpy_toio(data->mapped_ccb, &data->ilo_ccb, sizeof(struct ccb));
342 
343 	/* put packets on the send and receive queues */
344 	pkt_sz = 0;
345 	for (pkt_id = 0; pkt_id < NR_QENTRY; pkt_id++) {
346 		ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, pkt_sz);
347 		doorbell_set(driver_ccb);
348 	}
349 
350 	pkt_sz = desc_mem_sz(1);
351 	for (pkt_id = 0; pkt_id < NR_QENTRY; pkt_id++)
352 		ilo_pkt_enqueue(hw, driver_ccb, RECVQ, pkt_id, pkt_sz);
353 
354 	/* the ccb is ready to use */
355 	doorbell_clr(driver_ccb);
356 }
357 
358 static int ilo_ccb_verify(struct ilo_hwinfo *hw, struct ccb_data *data)
359 {
360 	int pkt_id, i;
361 	struct ccb *driver_ccb = &data->driver_ccb;
362 
363 	/* make sure iLO is really handling requests */
364 	for (i = MAX_WAIT; i > 0; i--) {
365 		if (ilo_pkt_dequeue(hw, driver_ccb, SENDQ, &pkt_id, NULL, NULL))
366 			break;
367 		udelay(WAIT_TIME);
368 	}
369 
370 	if (i == 0) {
371 		dev_err(&hw->ilo_dev->dev, "Open could not dequeue a packet\n");
372 		return -EBUSY;
373 	}
374 
375 	ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, 0);
376 	doorbell_set(driver_ccb);
377 	return 0;
378 }
379 
380 static inline int is_channel_reset(struct ccb *ccb)
381 {
382 	/* check for this particular channel needing a reset */
383 	return FIFOBARTOHANDLE(ccb->ccb_u1.send_fifobar)->reset;
384 }
385 
386 static inline void set_channel_reset(struct ccb *ccb)
387 {
388 	/* set a flag indicating this channel needs a reset */
389 	FIFOBARTOHANDLE(ccb->ccb_u1.send_fifobar)->reset = 1;
390 }
391 
392 static inline int get_device_outbound(struct ilo_hwinfo *hw)
393 {
394 	return ioread32(&hw->mmio_vaddr[DB_OUT]);
395 }
396 
397 static inline int is_db_reset(int db_out)
398 {
399 	return db_out & (1 << DB_RESET);
400 }
401 
402 static inline void clear_pending_db(struct ilo_hwinfo *hw, int clr)
403 {
404 	iowrite32(clr, &hw->mmio_vaddr[DB_OUT]);
405 }
406 
407 static inline void clear_device(struct ilo_hwinfo *hw)
408 {
409 	/* clear the device (reset bits, pending channel entries) */
410 	clear_pending_db(hw, -1);
411 }
412 
413 static inline void ilo_enable_interrupts(struct ilo_hwinfo *hw)
414 {
415 	iowrite8(ioread8(&hw->mmio_vaddr[DB_IRQ]) | 1, &hw->mmio_vaddr[DB_IRQ]);
416 }
417 
418 static inline void ilo_disable_interrupts(struct ilo_hwinfo *hw)
419 {
420 	iowrite8(ioread8(&hw->mmio_vaddr[DB_IRQ]) & ~1,
421 		 &hw->mmio_vaddr[DB_IRQ]);
422 }
423 
424 static void ilo_set_reset(struct ilo_hwinfo *hw)
425 {
426 	int slot;
427 
428 	/*
429 	 * Mapped memory is zeroed on ilo reset, so set a per ccb flag
430 	 * to indicate that this ccb needs to be closed and reopened.
431 	 */
432 	for (slot = 0; slot < max_ccb; slot++) {
433 		if (!hw->ccb_alloc[slot])
434 			continue;
435 		set_channel_reset(&hw->ccb_alloc[slot]->driver_ccb);
436 	}
437 }
438 
439 static ssize_t ilo_read(struct file *fp, char __user *buf,
440 			size_t len, loff_t *off)
441 {
442 	int err, found, cnt, pkt_id, pkt_len;
443 	struct ccb_data *data = fp->private_data;
444 	struct ccb *driver_ccb = &data->driver_ccb;
445 	struct ilo_hwinfo *hw = data->ilo_hw;
446 	void *pkt;
447 
448 	if (is_channel_reset(driver_ccb)) {
449 		/*
450 		 * If the device has been reset, applications
451 		 * need to close and reopen all ccbs.
452 		 */
453 		return -ENODEV;
454 	}
455 
456 	/*
457 	 * This function is to be called when data is expected
458 	 * in the channel, and will return an error if no packet is found
459 	 * during the loop below.  The sleep/retry logic is to allow
460 	 * applications to call read() immediately post write(),
461 	 * and give iLO some time to process the sent packet.
462 	 */
463 	cnt = 20;
464 	do {
465 		/* look for a received packet */
466 		found = ilo_pkt_dequeue(hw, driver_ccb, RECVQ, &pkt_id,
467 					&pkt_len, &pkt);
468 		if (found)
469 			break;
470 		cnt--;
471 		msleep(100);
472 	} while (!found && cnt);
473 
474 	if (!found)
475 		return -EAGAIN;
476 
477 	/* only copy the length of the received packet */
478 	if (pkt_len < len)
479 		len = pkt_len;
480 
481 	err = copy_to_user(buf, pkt, len);
482 
483 	/* return the received packet to the queue */
484 	ilo_pkt_enqueue(hw, driver_ccb, RECVQ, pkt_id, desc_mem_sz(1));
485 
486 	return err ? -EFAULT : len;
487 }
488 
489 static ssize_t ilo_write(struct file *fp, const char __user *buf,
490 			 size_t len, loff_t *off)
491 {
492 	int err, pkt_id, pkt_len;
493 	struct ccb_data *data = fp->private_data;
494 	struct ccb *driver_ccb = &data->driver_ccb;
495 	struct ilo_hwinfo *hw = data->ilo_hw;
496 	void *pkt;
497 
498 	if (is_channel_reset(driver_ccb))
499 		return -ENODEV;
500 
501 	/* get a packet to send the user command */
502 	if (!ilo_pkt_dequeue(hw, driver_ccb, SENDQ, &pkt_id, &pkt_len, &pkt))
503 		return -EBUSY;
504 
505 	/* limit the length to the length of the packet */
506 	if (pkt_len < len)
507 		len = pkt_len;
508 
509 	/* on failure, set the len to 0 to return empty packet to the device */
510 	err = copy_from_user(pkt, buf, len);
511 	if (err)
512 		len = 0;
513 
514 	/* send the packet */
515 	ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, len);
516 	doorbell_set(driver_ccb);
517 
518 	return err ? -EFAULT : len;
519 }
520 
521 static __poll_t ilo_poll(struct file *fp, poll_table *wait)
522 {
523 	struct ccb_data *data = fp->private_data;
524 	struct ccb *driver_ccb = &data->driver_ccb;
525 
526 	poll_wait(fp, &data->ccb_waitq, wait);
527 
528 	if (is_channel_reset(driver_ccb))
529 		return EPOLLERR;
530 	else if (ilo_pkt_recv(data->ilo_hw, driver_ccb))
531 		return EPOLLIN | EPOLLRDNORM;
532 
533 	return 0;
534 }
535 
536 static int ilo_close(struct inode *ip, struct file *fp)
537 {
538 	int slot;
539 	struct ccb_data *data;
540 	struct ilo_hwinfo *hw;
541 	unsigned long flags;
542 
543 	slot = iminor(ip) % max_ccb;
544 	hw = container_of(ip->i_cdev, struct ilo_hwinfo, cdev);
545 
546 	spin_lock(&hw->open_lock);
547 
548 	if (hw->ccb_alloc[slot]->ccb_cnt == 1) {
549 
550 		data = fp->private_data;
551 
552 		spin_lock_irqsave(&hw->alloc_lock, flags);
553 		hw->ccb_alloc[slot] = NULL;
554 		spin_unlock_irqrestore(&hw->alloc_lock, flags);
555 
556 		ilo_ccb_close(hw->ilo_dev, data);
557 
558 		kfree(data);
559 	} else
560 		hw->ccb_alloc[slot]->ccb_cnt--;
561 
562 	spin_unlock(&hw->open_lock);
563 
564 	return 0;
565 }
566 
567 static int ilo_open(struct inode *ip, struct file *fp)
568 {
569 	int slot, error;
570 	struct ccb_data *data;
571 	struct ilo_hwinfo *hw;
572 	unsigned long flags;
573 
574 	slot = iminor(ip) % max_ccb;
575 	hw = container_of(ip->i_cdev, struct ilo_hwinfo, cdev);
576 
577 	/* new ccb allocation */
578 	data = kzalloc_obj(*data);
579 	if (!data)
580 		return -ENOMEM;
581 
582 	spin_lock(&hw->open_lock);
583 
584 	/* each fd private_data holds sw/hw view of ccb */
585 	if (hw->ccb_alloc[slot] == NULL) {
586 		/* create a channel control block for this minor */
587 		error = ilo_ccb_setup(hw, data, slot);
588 		if (error) {
589 			kfree(data);
590 			goto out;
591 		}
592 
593 		data->ccb_cnt = 1;
594 		data->ccb_excl = fp->f_flags & O_EXCL;
595 		data->ilo_hw = hw;
596 		init_waitqueue_head(&data->ccb_waitq);
597 
598 		/* write the ccb to hw */
599 		spin_lock_irqsave(&hw->alloc_lock, flags);
600 		ilo_ccb_open(hw, data, slot);
601 		hw->ccb_alloc[slot] = data;
602 		spin_unlock_irqrestore(&hw->alloc_lock, flags);
603 
604 		/* make sure the channel is functional */
605 		error = ilo_ccb_verify(hw, data);
606 		if (error) {
607 
608 			spin_lock_irqsave(&hw->alloc_lock, flags);
609 			hw->ccb_alloc[slot] = NULL;
610 			spin_unlock_irqrestore(&hw->alloc_lock, flags);
611 
612 			ilo_ccb_close(hw->ilo_dev, data);
613 
614 			kfree(data);
615 			goto out;
616 		}
617 
618 	} else {
619 		kfree(data);
620 		if (fp->f_flags & O_EXCL || hw->ccb_alloc[slot]->ccb_excl) {
621 			/*
622 			 * The channel exists, and either this open
623 			 * or a previous open of this channel wants
624 			 * exclusive access.
625 			 */
626 			error = -EBUSY;
627 		} else {
628 			hw->ccb_alloc[slot]->ccb_cnt++;
629 			error = 0;
630 		}
631 	}
632 out:
633 	spin_unlock(&hw->open_lock);
634 
635 	if (!error)
636 		fp->private_data = hw->ccb_alloc[slot];
637 
638 	return error;
639 }
640 
641 static const struct file_operations ilo_fops = {
642 	.owner		= THIS_MODULE,
643 	.read		= ilo_read,
644 	.write		= ilo_write,
645 	.poll		= ilo_poll,
646 	.open 		= ilo_open,
647 	.release 	= ilo_close,
648 	.llseek		= noop_llseek,
649 };
650 
651 static irqreturn_t ilo_isr(int irq, void *data)
652 {
653 	struct ilo_hwinfo *hw = data;
654 	int pending, i;
655 
656 	spin_lock(&hw->alloc_lock);
657 
658 	/* check for ccbs which have data */
659 	pending = get_device_outbound(hw);
660 	if (!pending) {
661 		spin_unlock(&hw->alloc_lock);
662 		return IRQ_NONE;
663 	}
664 
665 	if (is_db_reset(pending)) {
666 		/* wake up all ccbs if the device was reset */
667 		pending = -1;
668 		ilo_set_reset(hw);
669 	}
670 
671 	for (i = 0; i < max_ccb; i++) {
672 		if (!hw->ccb_alloc[i])
673 			continue;
674 		if (pending & (1 << i))
675 			wake_up_interruptible(&hw->ccb_alloc[i]->ccb_waitq);
676 	}
677 
678 	/* clear the device of the channels that have been handled */
679 	clear_pending_db(hw, pending);
680 
681 	spin_unlock(&hw->alloc_lock);
682 
683 	return IRQ_HANDLED;
684 }
685 
686 static void ilo_unmap_device(struct pci_dev *pdev, struct ilo_hwinfo *hw)
687 {
688 	pci_iounmap(pdev, hw->db_vaddr);
689 	pci_iounmap(pdev, hw->ram_vaddr);
690 	pci_iounmap(pdev, hw->mmio_vaddr);
691 }
692 
693 static int ilo_map_device(struct pci_dev *pdev, struct ilo_hwinfo *hw)
694 {
695 	int bar;
696 	unsigned long off;
697 	u8 pci_rev_id;
698 	int rc;
699 
700 	/* map the memory mapped i/o registers */
701 	hw->mmio_vaddr = pci_iomap(pdev, 1, 0);
702 	if (hw->mmio_vaddr == NULL) {
703 		dev_err(&pdev->dev, "Error mapping mmio\n");
704 		goto out;
705 	}
706 
707 	/* map the adapter shared memory region */
708 	rc = pci_read_config_byte(pdev, PCI_REVISION_ID, &pci_rev_id);
709 	if (rc != 0) {
710 		dev_err(&pdev->dev, "Error reading PCI rev id: %d\n", rc);
711 		goto out;
712 	}
713 
714 	if (pci_rev_id >= PCI_REV_ID_NECHES) {
715 		bar = 5;
716 		/* Last 8k is reserved for CCBs */
717 		off = pci_resource_len(pdev, bar) - 0x2000;
718 	} else {
719 		bar = 2;
720 		off = 0;
721 	}
722 	hw->ram_vaddr = pci_iomap_range(pdev, bar, off, max_ccb * ILOHW_CCB_SZ);
723 	if (hw->ram_vaddr == NULL) {
724 		dev_err(&pdev->dev, "Error mapping shared mem\n");
725 		goto mmio_free;
726 	}
727 
728 	/* map the doorbell aperture */
729 	hw->db_vaddr = pci_iomap(pdev, 3, max_ccb * ONE_DB_SIZE);
730 	if (hw->db_vaddr == NULL) {
731 		dev_err(&pdev->dev, "Error mapping doorbell\n");
732 		goto ram_free;
733 	}
734 
735 	return 0;
736 ram_free:
737 	pci_iounmap(pdev, hw->ram_vaddr);
738 mmio_free:
739 	pci_iounmap(pdev, hw->mmio_vaddr);
740 out:
741 	return -ENOMEM;
742 }
743 
744 static void ilo_remove(struct pci_dev *pdev)
745 {
746 	int i, minor;
747 	struct ilo_hwinfo *ilo_hw = pci_get_drvdata(pdev);
748 
749 	if (!ilo_hw)
750 		return;
751 
752 	clear_device(ilo_hw);
753 
754 	minor = MINOR(ilo_hw->cdev.dev);
755 	for (i = minor; i < minor + max_ccb; i++)
756 		device_destroy(&ilo_class, MKDEV(ilo_major, i));
757 
758 	cdev_del(&ilo_hw->cdev);
759 	ilo_disable_interrupts(ilo_hw);
760 	free_irq(pdev->irq, ilo_hw);
761 	ilo_unmap_device(pdev, ilo_hw);
762 	pci_release_regions(pdev);
763 	/*
764 	 * pci_disable_device(pdev) used to be here. But this PCI device has
765 	 * two functions with interrupt lines connected to a single pin. The
766 	 * other one is a USB host controller. So when we disable the PIN here
767 	 * e.g. by rmmod hpilo, the controller stops working. It is because
768 	 * the interrupt link is disabled in ACPI since it is not refcounted
769 	 * yet. See acpi_pci_link_free_irq called from acpi_pci_irq_disable.
770 	 */
771 	kfree(ilo_hw);
772 	ilo_hwdev[(minor / max_ccb)] = 0;
773 }
774 
775 static int ilo_probe(struct pci_dev *pdev,
776 			       const struct pci_device_id *ent)
777 {
778 	int devnum, slot, start, error = 0;
779 	struct ilo_hwinfo *ilo_hw;
780 
781 	if (pci_match_id(ilo_blacklist, pdev)) {
782 		dev_dbg(&pdev->dev, "Not supported on this device\n");
783 		return -ENODEV;
784 	}
785 
786 	if (max_ccb > MAX_CCB)
787 		max_ccb = MAX_CCB;
788 	else if (max_ccb < MIN_CCB)
789 		max_ccb = MIN_CCB;
790 
791 	/* find a free range for device files */
792 	for (devnum = 0; devnum < MAX_ILO_DEV; devnum++) {
793 		if (ilo_hwdev[devnum] == 0) {
794 			ilo_hwdev[devnum] = 1;
795 			break;
796 		}
797 	}
798 
799 	if (devnum == MAX_ILO_DEV) {
800 		dev_err(&pdev->dev, "Error finding free device\n");
801 		return -ENODEV;
802 	}
803 
804 	/* track global allocations for this device */
805 	error = -ENOMEM;
806 	ilo_hw = kzalloc_obj(*ilo_hw);
807 	if (!ilo_hw)
808 		goto out;
809 
810 	ilo_hw->ilo_dev = pdev;
811 	spin_lock_init(&ilo_hw->alloc_lock);
812 	spin_lock_init(&ilo_hw->fifo_lock);
813 	spin_lock_init(&ilo_hw->open_lock);
814 
815 	error = pci_enable_device(pdev);
816 	if (error)
817 		goto free;
818 
819 	pci_set_master(pdev);
820 
821 	error = pci_request_regions(pdev, ILO_NAME);
822 	if (error)
823 		goto disable;
824 
825 	error = ilo_map_device(pdev, ilo_hw);
826 	if (error)
827 		goto free_regions;
828 
829 	pci_set_drvdata(pdev, ilo_hw);
830 	clear_device(ilo_hw);
831 
832 	error = request_irq(pdev->irq, ilo_isr, IRQF_SHARED, "hpilo", ilo_hw);
833 	if (error)
834 		goto unmap;
835 
836 	ilo_enable_interrupts(ilo_hw);
837 
838 	cdev_init(&ilo_hw->cdev, &ilo_fops);
839 	ilo_hw->cdev.owner = THIS_MODULE;
840 	start = devnum * max_ccb;
841 	error = cdev_add(&ilo_hw->cdev, MKDEV(ilo_major, start), max_ccb);
842 	if (error) {
843 		dev_err(&pdev->dev, "Could not add cdev\n");
844 		goto remove_isr;
845 	}
846 
847 	for (slot = 0; slot < max_ccb; slot++) {
848 		struct device *dev;
849 		dev = device_create(&ilo_class, &pdev->dev,
850 				    MKDEV(ilo_major, start + slot), NULL,
851 				    "hpilo!d%dccb%d", devnum, slot);
852 		if (IS_ERR(dev))
853 			dev_err(&pdev->dev, "Could not create files\n");
854 	}
855 
856 	return 0;
857 remove_isr:
858 	ilo_disable_interrupts(ilo_hw);
859 	free_irq(pdev->irq, ilo_hw);
860 unmap:
861 	ilo_unmap_device(pdev, ilo_hw);
862 free_regions:
863 	pci_release_regions(pdev);
864 disable:
865 /*	pci_disable_device(pdev);  see comment in ilo_remove */
866 free:
867 	kfree(ilo_hw);
868 out:
869 	ilo_hwdev[devnum] = 0;
870 	return error;
871 }
872 
873 static const struct pci_device_id ilo_devices[] = {
874 	{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB204) },
875 	{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3307) },
876 	{ }
877 };
878 MODULE_DEVICE_TABLE(pci, ilo_devices);
879 
880 static struct pci_driver ilo_driver = {
881 	.name 	  = ILO_NAME,
882 	.id_table = ilo_devices,
883 	.probe 	  = ilo_probe,
884 	.remove   = ilo_remove,
885 };
886 
887 static int __init ilo_init(void)
888 {
889 	int error;
890 	dev_t dev;
891 
892 	error = class_register(&ilo_class);
893 	if (error)
894 		goto out;
895 
896 	error = alloc_chrdev_region(&dev, 0, MAX_OPEN, ILO_NAME);
897 	if (error)
898 		goto class_destroy;
899 
900 	ilo_major = MAJOR(dev);
901 
902 	error =	pci_register_driver(&ilo_driver);
903 	if (error)
904 		goto chr_remove;
905 
906 	return 0;
907 chr_remove:
908 	unregister_chrdev_region(dev, MAX_OPEN);
909 class_destroy:
910 	class_unregister(&ilo_class);
911 out:
912 	return error;
913 }
914 
915 static void __exit ilo_exit(void)
916 {
917 	pci_unregister_driver(&ilo_driver);
918 	unregister_chrdev_region(MKDEV(ilo_major, 0), MAX_OPEN);
919 	class_unregister(&ilo_class);
920 }
921 
922 MODULE_VERSION("1.5.0");
923 MODULE_ALIAS(ILO_NAME);
924 MODULE_DESCRIPTION(ILO_NAME);
925 MODULE_AUTHOR("David Altobelli <david.altobelli@hpe.com>");
926 MODULE_LICENSE("GPL v2");
927 
928 module_param(max_ccb, uint, 0444);
929 MODULE_PARM_DESC(max_ccb, "Maximum number of HP iLO channels to attach (8-24)(default=16)");
930 
931 module_init(ilo_init);
932 module_exit(ilo_exit);
933