xref: /openbmc/linux/drivers/misc/hpilo.c (revision 2c684d89)
1 /*
2  * Driver for the HP iLO management processor.
3  *
4  * Copyright (C) 2008 Hewlett-Packard Development Company, L.P.
5  *	David Altobelli <david.altobelli@hpe.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #include <linux/kernel.h>
12 #include <linux/types.h>
13 #include <linux/module.h>
14 #include <linux/fs.h>
15 #include <linux/pci.h>
16 #include <linux/interrupt.h>
17 #include <linux/ioport.h>
18 #include <linux/device.h>
19 #include <linux/file.h>
20 #include <linux/cdev.h>
21 #include <linux/sched.h>
22 #include <linux/spinlock.h>
23 #include <linux/delay.h>
24 #include <linux/uaccess.h>
25 #include <linux/io.h>
26 #include <linux/wait.h>
27 #include <linux/poll.h>
28 #include <linux/slab.h>
29 #include "hpilo.h"
30 
31 static struct class *ilo_class;
32 static unsigned int ilo_major;
33 static unsigned int max_ccb = 16;
34 static char ilo_hwdev[MAX_ILO_DEV];
35 
36 static inline int get_entry_id(int entry)
37 {
38 	return (entry & ENTRY_MASK_DESCRIPTOR) >> ENTRY_BITPOS_DESCRIPTOR;
39 }
40 
41 static inline int get_entry_len(int entry)
42 {
43 	return ((entry & ENTRY_MASK_QWORDS) >> ENTRY_BITPOS_QWORDS) << 3;
44 }
45 
46 static inline int mk_entry(int id, int len)
47 {
48 	int qlen = len & 7 ? (len >> 3) + 1 : len >> 3;
49 	return id << ENTRY_BITPOS_DESCRIPTOR | qlen << ENTRY_BITPOS_QWORDS;
50 }
51 
52 static inline int desc_mem_sz(int nr_entry)
53 {
54 	return nr_entry << L2_QENTRY_SZ;
55 }
56 
57 /*
58  * FIFO queues, shared with hardware.
59  *
60  * If a queue has empty slots, an entry is added to the queue tail,
61  * and that entry is marked as occupied.
62  * Entries can be dequeued from the head of the list, when the device
63  * has marked the entry as consumed.
64  *
65  * Returns true on successful queue/dequeue, false on failure.
66  */
67 static int fifo_enqueue(struct ilo_hwinfo *hw, char *fifobar, int entry)
68 {
69 	struct fifo *fifo_q = FIFOBARTOHANDLE(fifobar);
70 	unsigned long flags;
71 	int ret = 0;
72 
73 	spin_lock_irqsave(&hw->fifo_lock, flags);
74 	if (!(fifo_q->fifobar[(fifo_q->tail + 1) & fifo_q->imask]
75 	      & ENTRY_MASK_O)) {
76 		fifo_q->fifobar[fifo_q->tail & fifo_q->imask] |=
77 				(entry & ENTRY_MASK_NOSTATE) | fifo_q->merge;
78 		fifo_q->tail += 1;
79 		ret = 1;
80 	}
81 	spin_unlock_irqrestore(&hw->fifo_lock, flags);
82 
83 	return ret;
84 }
85 
86 static int fifo_dequeue(struct ilo_hwinfo *hw, char *fifobar, int *entry)
87 {
88 	struct fifo *fifo_q = FIFOBARTOHANDLE(fifobar);
89 	unsigned long flags;
90 	int ret = 0;
91 	u64 c;
92 
93 	spin_lock_irqsave(&hw->fifo_lock, flags);
94 	c = fifo_q->fifobar[fifo_q->head & fifo_q->imask];
95 	if (c & ENTRY_MASK_C) {
96 		if (entry)
97 			*entry = c & ENTRY_MASK_NOSTATE;
98 
99 		fifo_q->fifobar[fifo_q->head & fifo_q->imask] =
100 							(c | ENTRY_MASK) + 1;
101 		fifo_q->head += 1;
102 		ret = 1;
103 	}
104 	spin_unlock_irqrestore(&hw->fifo_lock, flags);
105 
106 	return ret;
107 }
108 
109 static int fifo_check_recv(struct ilo_hwinfo *hw, char *fifobar)
110 {
111 	struct fifo *fifo_q = FIFOBARTOHANDLE(fifobar);
112 	unsigned long flags;
113 	int ret = 0;
114 	u64 c;
115 
116 	spin_lock_irqsave(&hw->fifo_lock, flags);
117 	c = fifo_q->fifobar[fifo_q->head & fifo_q->imask];
118 	if (c & ENTRY_MASK_C)
119 		ret = 1;
120 	spin_unlock_irqrestore(&hw->fifo_lock, flags);
121 
122 	return ret;
123 }
124 
125 static int ilo_pkt_enqueue(struct ilo_hwinfo *hw, struct ccb *ccb,
126 			   int dir, int id, int len)
127 {
128 	char *fifobar;
129 	int entry;
130 
131 	if (dir == SENDQ)
132 		fifobar = ccb->ccb_u1.send_fifobar;
133 	else
134 		fifobar = ccb->ccb_u3.recv_fifobar;
135 
136 	entry = mk_entry(id, len);
137 	return fifo_enqueue(hw, fifobar, entry);
138 }
139 
140 static int ilo_pkt_dequeue(struct ilo_hwinfo *hw, struct ccb *ccb,
141 			   int dir, int *id, int *len, void **pkt)
142 {
143 	char *fifobar, *desc;
144 	int entry = 0, pkt_id = 0;
145 	int ret;
146 
147 	if (dir == SENDQ) {
148 		fifobar = ccb->ccb_u1.send_fifobar;
149 		desc = ccb->ccb_u2.send_desc;
150 	} else {
151 		fifobar = ccb->ccb_u3.recv_fifobar;
152 		desc = ccb->ccb_u4.recv_desc;
153 	}
154 
155 	ret = fifo_dequeue(hw, fifobar, &entry);
156 	if (ret) {
157 		pkt_id = get_entry_id(entry);
158 		if (id)
159 			*id = pkt_id;
160 		if (len)
161 			*len = get_entry_len(entry);
162 		if (pkt)
163 			*pkt = (void *)(desc + desc_mem_sz(pkt_id));
164 	}
165 
166 	return ret;
167 }
168 
169 static int ilo_pkt_recv(struct ilo_hwinfo *hw, struct ccb *ccb)
170 {
171 	char *fifobar = ccb->ccb_u3.recv_fifobar;
172 
173 	return fifo_check_recv(hw, fifobar);
174 }
175 
176 static inline void doorbell_set(struct ccb *ccb)
177 {
178 	iowrite8(1, ccb->ccb_u5.db_base);
179 }
180 
181 static inline void doorbell_clr(struct ccb *ccb)
182 {
183 	iowrite8(2, ccb->ccb_u5.db_base);
184 }
185 
186 static inline int ctrl_set(int l2sz, int idxmask, int desclim)
187 {
188 	int active = 0, go = 1;
189 	return l2sz << CTRL_BITPOS_L2SZ |
190 	       idxmask << CTRL_BITPOS_FIFOINDEXMASK |
191 	       desclim << CTRL_BITPOS_DESCLIMIT |
192 	       active << CTRL_BITPOS_A |
193 	       go << CTRL_BITPOS_G;
194 }
195 
196 static void ctrl_setup(struct ccb *ccb, int nr_desc, int l2desc_sz)
197 {
198 	/* for simplicity, use the same parameters for send and recv ctrls */
199 	ccb->send_ctrl = ctrl_set(l2desc_sz, nr_desc-1, nr_desc-1);
200 	ccb->recv_ctrl = ctrl_set(l2desc_sz, nr_desc-1, nr_desc-1);
201 }
202 
203 static inline int fifo_sz(int nr_entry)
204 {
205 	/* size of a fifo is determined by the number of entries it contains */
206 	return (nr_entry * sizeof(u64)) + FIFOHANDLESIZE;
207 }
208 
209 static void fifo_setup(void *base_addr, int nr_entry)
210 {
211 	struct fifo *fifo_q = base_addr;
212 	int i;
213 
214 	/* set up an empty fifo */
215 	fifo_q->head = 0;
216 	fifo_q->tail = 0;
217 	fifo_q->reset = 0;
218 	fifo_q->nrents = nr_entry;
219 	fifo_q->imask = nr_entry - 1;
220 	fifo_q->merge = ENTRY_MASK_O;
221 
222 	for (i = 0; i < nr_entry; i++)
223 		fifo_q->fifobar[i] = 0;
224 }
225 
226 static void ilo_ccb_close(struct pci_dev *pdev, struct ccb_data *data)
227 {
228 	struct ccb *driver_ccb = &data->driver_ccb;
229 	struct ccb __iomem *device_ccb = data->mapped_ccb;
230 	int retries;
231 
232 	/* complicated dance to tell the hw we are stopping */
233 	doorbell_clr(driver_ccb);
234 	iowrite32(ioread32(&device_ccb->send_ctrl) & ~(1 << CTRL_BITPOS_G),
235 		  &device_ccb->send_ctrl);
236 	iowrite32(ioread32(&device_ccb->recv_ctrl) & ~(1 << CTRL_BITPOS_G),
237 		  &device_ccb->recv_ctrl);
238 
239 	/* give iLO some time to process stop request */
240 	for (retries = MAX_WAIT; retries > 0; retries--) {
241 		doorbell_set(driver_ccb);
242 		udelay(WAIT_TIME);
243 		if (!(ioread32(&device_ccb->send_ctrl) & (1 << CTRL_BITPOS_A))
244 		    &&
245 		    !(ioread32(&device_ccb->recv_ctrl) & (1 << CTRL_BITPOS_A)))
246 			break;
247 	}
248 	if (retries == 0)
249 		dev_err(&pdev->dev, "Closing, but controller still active\n");
250 
251 	/* clear the hw ccb */
252 	memset_io(device_ccb, 0, sizeof(struct ccb));
253 
254 	/* free resources used to back send/recv queues */
255 	pci_free_consistent(pdev, data->dma_size, data->dma_va, data->dma_pa);
256 }
257 
258 static int ilo_ccb_setup(struct ilo_hwinfo *hw, struct ccb_data *data, int slot)
259 {
260 	char *dma_va;
261 	dma_addr_t dma_pa;
262 	struct ccb *driver_ccb, *ilo_ccb;
263 
264 	driver_ccb = &data->driver_ccb;
265 	ilo_ccb = &data->ilo_ccb;
266 
267 	data->dma_size = 2 * fifo_sz(NR_QENTRY) +
268 			 2 * desc_mem_sz(NR_QENTRY) +
269 			 ILO_START_ALIGN + ILO_CACHE_SZ;
270 
271 	data->dma_va = pci_alloc_consistent(hw->ilo_dev, data->dma_size,
272 					    &data->dma_pa);
273 	if (!data->dma_va)
274 		return -ENOMEM;
275 
276 	dma_va = (char *)data->dma_va;
277 	dma_pa = data->dma_pa;
278 
279 	memset(dma_va, 0, data->dma_size);
280 
281 	dma_va = (char *)roundup((unsigned long)dma_va, ILO_START_ALIGN);
282 	dma_pa = roundup(dma_pa, ILO_START_ALIGN);
283 
284 	/*
285 	 * Create two ccb's, one with virt addrs, one with phys addrs.
286 	 * Copy the phys addr ccb to device shared mem.
287 	 */
288 	ctrl_setup(driver_ccb, NR_QENTRY, L2_QENTRY_SZ);
289 	ctrl_setup(ilo_ccb, NR_QENTRY, L2_QENTRY_SZ);
290 
291 	fifo_setup(dma_va, NR_QENTRY);
292 	driver_ccb->ccb_u1.send_fifobar = dma_va + FIFOHANDLESIZE;
293 	ilo_ccb->ccb_u1.send_fifobar_pa = dma_pa + FIFOHANDLESIZE;
294 	dma_va += fifo_sz(NR_QENTRY);
295 	dma_pa += fifo_sz(NR_QENTRY);
296 
297 	dma_va = (char *)roundup((unsigned long)dma_va, ILO_CACHE_SZ);
298 	dma_pa = roundup(dma_pa, ILO_CACHE_SZ);
299 
300 	fifo_setup(dma_va, NR_QENTRY);
301 	driver_ccb->ccb_u3.recv_fifobar = dma_va + FIFOHANDLESIZE;
302 	ilo_ccb->ccb_u3.recv_fifobar_pa = dma_pa + FIFOHANDLESIZE;
303 	dma_va += fifo_sz(NR_QENTRY);
304 	dma_pa += fifo_sz(NR_QENTRY);
305 
306 	driver_ccb->ccb_u2.send_desc = dma_va;
307 	ilo_ccb->ccb_u2.send_desc_pa = dma_pa;
308 	dma_pa += desc_mem_sz(NR_QENTRY);
309 	dma_va += desc_mem_sz(NR_QENTRY);
310 
311 	driver_ccb->ccb_u4.recv_desc = dma_va;
312 	ilo_ccb->ccb_u4.recv_desc_pa = dma_pa;
313 
314 	driver_ccb->channel = slot;
315 	ilo_ccb->channel = slot;
316 
317 	driver_ccb->ccb_u5.db_base = hw->db_vaddr + (slot << L2_DB_SIZE);
318 	ilo_ccb->ccb_u5.db_base = NULL; /* hw ccb's doorbell is not used */
319 
320 	return 0;
321 }
322 
323 static void ilo_ccb_open(struct ilo_hwinfo *hw, struct ccb_data *data, int slot)
324 {
325 	int pkt_id, pkt_sz;
326 	struct ccb *driver_ccb = &data->driver_ccb;
327 
328 	/* copy the ccb with physical addrs to device memory */
329 	data->mapped_ccb = (struct ccb __iomem *)
330 				(hw->ram_vaddr + (slot * ILOHW_CCB_SZ));
331 	memcpy_toio(data->mapped_ccb, &data->ilo_ccb, sizeof(struct ccb));
332 
333 	/* put packets on the send and receive queues */
334 	pkt_sz = 0;
335 	for (pkt_id = 0; pkt_id < NR_QENTRY; pkt_id++) {
336 		ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, pkt_sz);
337 		doorbell_set(driver_ccb);
338 	}
339 
340 	pkt_sz = desc_mem_sz(1);
341 	for (pkt_id = 0; pkt_id < NR_QENTRY; pkt_id++)
342 		ilo_pkt_enqueue(hw, driver_ccb, RECVQ, pkt_id, pkt_sz);
343 
344 	/* the ccb is ready to use */
345 	doorbell_clr(driver_ccb);
346 }
347 
348 static int ilo_ccb_verify(struct ilo_hwinfo *hw, struct ccb_data *data)
349 {
350 	int pkt_id, i;
351 	struct ccb *driver_ccb = &data->driver_ccb;
352 
353 	/* make sure iLO is really handling requests */
354 	for (i = MAX_WAIT; i > 0; i--) {
355 		if (ilo_pkt_dequeue(hw, driver_ccb, SENDQ, &pkt_id, NULL, NULL))
356 			break;
357 		udelay(WAIT_TIME);
358 	}
359 
360 	if (i == 0) {
361 		dev_err(&hw->ilo_dev->dev, "Open could not dequeue a packet\n");
362 		return -EBUSY;
363 	}
364 
365 	ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, 0);
366 	doorbell_set(driver_ccb);
367 	return 0;
368 }
369 
370 static inline int is_channel_reset(struct ccb *ccb)
371 {
372 	/* check for this particular channel needing a reset */
373 	return FIFOBARTOHANDLE(ccb->ccb_u1.send_fifobar)->reset;
374 }
375 
376 static inline void set_channel_reset(struct ccb *ccb)
377 {
378 	/* set a flag indicating this channel needs a reset */
379 	FIFOBARTOHANDLE(ccb->ccb_u1.send_fifobar)->reset = 1;
380 }
381 
382 static inline int get_device_outbound(struct ilo_hwinfo *hw)
383 {
384 	return ioread32(&hw->mmio_vaddr[DB_OUT]);
385 }
386 
387 static inline int is_db_reset(int db_out)
388 {
389 	return db_out & (1 << DB_RESET);
390 }
391 
392 static inline int is_device_reset(struct ilo_hwinfo *hw)
393 {
394 	/* check for global reset condition */
395 	return is_db_reset(get_device_outbound(hw));
396 }
397 
398 static inline void clear_pending_db(struct ilo_hwinfo *hw, int clr)
399 {
400 	iowrite32(clr, &hw->mmio_vaddr[DB_OUT]);
401 }
402 
403 static inline void clear_device(struct ilo_hwinfo *hw)
404 {
405 	/* clear the device (reset bits, pending channel entries) */
406 	clear_pending_db(hw, -1);
407 }
408 
409 static inline void ilo_enable_interrupts(struct ilo_hwinfo *hw)
410 {
411 	iowrite8(ioread8(&hw->mmio_vaddr[DB_IRQ]) | 1, &hw->mmio_vaddr[DB_IRQ]);
412 }
413 
414 static inline void ilo_disable_interrupts(struct ilo_hwinfo *hw)
415 {
416 	iowrite8(ioread8(&hw->mmio_vaddr[DB_IRQ]) & ~1,
417 		 &hw->mmio_vaddr[DB_IRQ]);
418 }
419 
420 static void ilo_set_reset(struct ilo_hwinfo *hw)
421 {
422 	int slot;
423 
424 	/*
425 	 * Mapped memory is zeroed on ilo reset, so set a per ccb flag
426 	 * to indicate that this ccb needs to be closed and reopened.
427 	 */
428 	for (slot = 0; slot < max_ccb; slot++) {
429 		if (!hw->ccb_alloc[slot])
430 			continue;
431 		set_channel_reset(&hw->ccb_alloc[slot]->driver_ccb);
432 	}
433 }
434 
435 static ssize_t ilo_read(struct file *fp, char __user *buf,
436 			size_t len, loff_t *off)
437 {
438 	int err, found, cnt, pkt_id, pkt_len;
439 	struct ccb_data *data = fp->private_data;
440 	struct ccb *driver_ccb = &data->driver_ccb;
441 	struct ilo_hwinfo *hw = data->ilo_hw;
442 	void *pkt;
443 
444 	if (is_channel_reset(driver_ccb)) {
445 		/*
446 		 * If the device has been reset, applications
447 		 * need to close and reopen all ccbs.
448 		 */
449 		return -ENODEV;
450 	}
451 
452 	/*
453 	 * This function is to be called when data is expected
454 	 * in the channel, and will return an error if no packet is found
455 	 * during the loop below.  The sleep/retry logic is to allow
456 	 * applications to call read() immediately post write(),
457 	 * and give iLO some time to process the sent packet.
458 	 */
459 	cnt = 20;
460 	do {
461 		/* look for a received packet */
462 		found = ilo_pkt_dequeue(hw, driver_ccb, RECVQ, &pkt_id,
463 					&pkt_len, &pkt);
464 		if (found)
465 			break;
466 		cnt--;
467 		msleep(100);
468 	} while (!found && cnt);
469 
470 	if (!found)
471 		return -EAGAIN;
472 
473 	/* only copy the length of the received packet */
474 	if (pkt_len < len)
475 		len = pkt_len;
476 
477 	err = copy_to_user(buf, pkt, len);
478 
479 	/* return the received packet to the queue */
480 	ilo_pkt_enqueue(hw, driver_ccb, RECVQ, pkt_id, desc_mem_sz(1));
481 
482 	return err ? -EFAULT : len;
483 }
484 
485 static ssize_t ilo_write(struct file *fp, const char __user *buf,
486 			 size_t len, loff_t *off)
487 {
488 	int err, pkt_id, pkt_len;
489 	struct ccb_data *data = fp->private_data;
490 	struct ccb *driver_ccb = &data->driver_ccb;
491 	struct ilo_hwinfo *hw = data->ilo_hw;
492 	void *pkt;
493 
494 	if (is_channel_reset(driver_ccb))
495 		return -ENODEV;
496 
497 	/* get a packet to send the user command */
498 	if (!ilo_pkt_dequeue(hw, driver_ccb, SENDQ, &pkt_id, &pkt_len, &pkt))
499 		return -EBUSY;
500 
501 	/* limit the length to the length of the packet */
502 	if (pkt_len < len)
503 		len = pkt_len;
504 
505 	/* on failure, set the len to 0 to return empty packet to the device */
506 	err = copy_from_user(pkt, buf, len);
507 	if (err)
508 		len = 0;
509 
510 	/* send the packet */
511 	ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, len);
512 	doorbell_set(driver_ccb);
513 
514 	return err ? -EFAULT : len;
515 }
516 
517 static unsigned int ilo_poll(struct file *fp, poll_table *wait)
518 {
519 	struct ccb_data *data = fp->private_data;
520 	struct ccb *driver_ccb = &data->driver_ccb;
521 
522 	poll_wait(fp, &data->ccb_waitq, wait);
523 
524 	if (is_channel_reset(driver_ccb))
525 		return POLLERR;
526 	else if (ilo_pkt_recv(data->ilo_hw, driver_ccb))
527 		return POLLIN | POLLRDNORM;
528 
529 	return 0;
530 }
531 
532 static int ilo_close(struct inode *ip, struct file *fp)
533 {
534 	int slot;
535 	struct ccb_data *data;
536 	struct ilo_hwinfo *hw;
537 	unsigned long flags;
538 
539 	slot = iminor(ip) % max_ccb;
540 	hw = container_of(ip->i_cdev, struct ilo_hwinfo, cdev);
541 
542 	spin_lock(&hw->open_lock);
543 
544 	if (hw->ccb_alloc[slot]->ccb_cnt == 1) {
545 
546 		data = fp->private_data;
547 
548 		spin_lock_irqsave(&hw->alloc_lock, flags);
549 		hw->ccb_alloc[slot] = NULL;
550 		spin_unlock_irqrestore(&hw->alloc_lock, flags);
551 
552 		ilo_ccb_close(hw->ilo_dev, data);
553 
554 		kfree(data);
555 	} else
556 		hw->ccb_alloc[slot]->ccb_cnt--;
557 
558 	spin_unlock(&hw->open_lock);
559 
560 	return 0;
561 }
562 
563 static int ilo_open(struct inode *ip, struct file *fp)
564 {
565 	int slot, error;
566 	struct ccb_data *data;
567 	struct ilo_hwinfo *hw;
568 	unsigned long flags;
569 
570 	slot = iminor(ip) % max_ccb;
571 	hw = container_of(ip->i_cdev, struct ilo_hwinfo, cdev);
572 
573 	/* new ccb allocation */
574 	data = kzalloc(sizeof(*data), GFP_KERNEL);
575 	if (!data)
576 		return -ENOMEM;
577 
578 	spin_lock(&hw->open_lock);
579 
580 	/* each fd private_data holds sw/hw view of ccb */
581 	if (hw->ccb_alloc[slot] == NULL) {
582 		/* create a channel control block for this minor */
583 		error = ilo_ccb_setup(hw, data, slot);
584 		if (error) {
585 			kfree(data);
586 			goto out;
587 		}
588 
589 		data->ccb_cnt = 1;
590 		data->ccb_excl = fp->f_flags & O_EXCL;
591 		data->ilo_hw = hw;
592 		init_waitqueue_head(&data->ccb_waitq);
593 
594 		/* write the ccb to hw */
595 		spin_lock_irqsave(&hw->alloc_lock, flags);
596 		ilo_ccb_open(hw, data, slot);
597 		hw->ccb_alloc[slot] = data;
598 		spin_unlock_irqrestore(&hw->alloc_lock, flags);
599 
600 		/* make sure the channel is functional */
601 		error = ilo_ccb_verify(hw, data);
602 		if (error) {
603 
604 			spin_lock_irqsave(&hw->alloc_lock, flags);
605 			hw->ccb_alloc[slot] = NULL;
606 			spin_unlock_irqrestore(&hw->alloc_lock, flags);
607 
608 			ilo_ccb_close(hw->ilo_dev, data);
609 
610 			kfree(data);
611 			goto out;
612 		}
613 
614 	} else {
615 		kfree(data);
616 		if (fp->f_flags & O_EXCL || hw->ccb_alloc[slot]->ccb_excl) {
617 			/*
618 			 * The channel exists, and either this open
619 			 * or a previous open of this channel wants
620 			 * exclusive access.
621 			 */
622 			error = -EBUSY;
623 		} else {
624 			hw->ccb_alloc[slot]->ccb_cnt++;
625 			error = 0;
626 		}
627 	}
628 out:
629 	spin_unlock(&hw->open_lock);
630 
631 	if (!error)
632 		fp->private_data = hw->ccb_alloc[slot];
633 
634 	return error;
635 }
636 
637 static const struct file_operations ilo_fops = {
638 	.owner		= THIS_MODULE,
639 	.read		= ilo_read,
640 	.write		= ilo_write,
641 	.poll		= ilo_poll,
642 	.open 		= ilo_open,
643 	.release 	= ilo_close,
644 	.llseek		= noop_llseek,
645 };
646 
647 static irqreturn_t ilo_isr(int irq, void *data)
648 {
649 	struct ilo_hwinfo *hw = data;
650 	int pending, i;
651 
652 	spin_lock(&hw->alloc_lock);
653 
654 	/* check for ccbs which have data */
655 	pending = get_device_outbound(hw);
656 	if (!pending) {
657 		spin_unlock(&hw->alloc_lock);
658 		return IRQ_NONE;
659 	}
660 
661 	if (is_db_reset(pending)) {
662 		/* wake up all ccbs if the device was reset */
663 		pending = -1;
664 		ilo_set_reset(hw);
665 	}
666 
667 	for (i = 0; i < max_ccb; i++) {
668 		if (!hw->ccb_alloc[i])
669 			continue;
670 		if (pending & (1 << i))
671 			wake_up_interruptible(&hw->ccb_alloc[i]->ccb_waitq);
672 	}
673 
674 	/* clear the device of the channels that have been handled */
675 	clear_pending_db(hw, pending);
676 
677 	spin_unlock(&hw->alloc_lock);
678 
679 	return IRQ_HANDLED;
680 }
681 
682 static void ilo_unmap_device(struct pci_dev *pdev, struct ilo_hwinfo *hw)
683 {
684 	pci_iounmap(pdev, hw->db_vaddr);
685 	pci_iounmap(pdev, hw->ram_vaddr);
686 	pci_iounmap(pdev, hw->mmio_vaddr);
687 }
688 
689 static int ilo_map_device(struct pci_dev *pdev, struct ilo_hwinfo *hw)
690 {
691 	int error = -ENOMEM;
692 
693 	/* map the memory mapped i/o registers */
694 	hw->mmio_vaddr = pci_iomap(pdev, 1, 0);
695 	if (hw->mmio_vaddr == NULL) {
696 		dev_err(&pdev->dev, "Error mapping mmio\n");
697 		goto out;
698 	}
699 
700 	/* map the adapter shared memory region */
701 	hw->ram_vaddr = pci_iomap(pdev, 2, max_ccb * ILOHW_CCB_SZ);
702 	if (hw->ram_vaddr == NULL) {
703 		dev_err(&pdev->dev, "Error mapping shared mem\n");
704 		goto mmio_free;
705 	}
706 
707 	/* map the doorbell aperture */
708 	hw->db_vaddr = pci_iomap(pdev, 3, max_ccb * ONE_DB_SIZE);
709 	if (hw->db_vaddr == NULL) {
710 		dev_err(&pdev->dev, "Error mapping doorbell\n");
711 		goto ram_free;
712 	}
713 
714 	return 0;
715 ram_free:
716 	pci_iounmap(pdev, hw->ram_vaddr);
717 mmio_free:
718 	pci_iounmap(pdev, hw->mmio_vaddr);
719 out:
720 	return error;
721 }
722 
723 static void ilo_remove(struct pci_dev *pdev)
724 {
725 	int i, minor;
726 	struct ilo_hwinfo *ilo_hw = pci_get_drvdata(pdev);
727 
728 	if (!ilo_hw)
729 		return;
730 
731 	clear_device(ilo_hw);
732 
733 	minor = MINOR(ilo_hw->cdev.dev);
734 	for (i = minor; i < minor + max_ccb; i++)
735 		device_destroy(ilo_class, MKDEV(ilo_major, i));
736 
737 	cdev_del(&ilo_hw->cdev);
738 	ilo_disable_interrupts(ilo_hw);
739 	free_irq(pdev->irq, ilo_hw);
740 	ilo_unmap_device(pdev, ilo_hw);
741 	pci_release_regions(pdev);
742 	/*
743 	 * pci_disable_device(pdev) used to be here. But this PCI device has
744 	 * two functions with interrupt lines connected to a single pin. The
745 	 * other one is a USB host controller. So when we disable the PIN here
746 	 * e.g. by rmmod hpilo, the controller stops working. It is because
747 	 * the interrupt link is disabled in ACPI since it is not refcounted
748 	 * yet. See acpi_pci_link_free_irq called from acpi_pci_irq_disable.
749 	 */
750 	kfree(ilo_hw);
751 	ilo_hwdev[(minor / max_ccb)] = 0;
752 }
753 
754 static int ilo_probe(struct pci_dev *pdev,
755 			       const struct pci_device_id *ent)
756 {
757 	int devnum, minor, start, error = 0;
758 	struct ilo_hwinfo *ilo_hw;
759 
760 	/* Ignore subsystem_device = 0x1979 (set by BIOS)  */
761 	if (pdev->subsystem_device == 0x1979)
762 		return 0;
763 
764 	if (max_ccb > MAX_CCB)
765 		max_ccb = MAX_CCB;
766 	else if (max_ccb < MIN_CCB)
767 		max_ccb = MIN_CCB;
768 
769 	/* find a free range for device files */
770 	for (devnum = 0; devnum < MAX_ILO_DEV; devnum++) {
771 		if (ilo_hwdev[devnum] == 0) {
772 			ilo_hwdev[devnum] = 1;
773 			break;
774 		}
775 	}
776 
777 	if (devnum == MAX_ILO_DEV) {
778 		dev_err(&pdev->dev, "Error finding free device\n");
779 		return -ENODEV;
780 	}
781 
782 	/* track global allocations for this device */
783 	error = -ENOMEM;
784 	ilo_hw = kzalloc(sizeof(*ilo_hw), GFP_KERNEL);
785 	if (!ilo_hw)
786 		goto out;
787 
788 	ilo_hw->ilo_dev = pdev;
789 	spin_lock_init(&ilo_hw->alloc_lock);
790 	spin_lock_init(&ilo_hw->fifo_lock);
791 	spin_lock_init(&ilo_hw->open_lock);
792 
793 	error = pci_enable_device(pdev);
794 	if (error)
795 		goto free;
796 
797 	pci_set_master(pdev);
798 
799 	error = pci_request_regions(pdev, ILO_NAME);
800 	if (error)
801 		goto disable;
802 
803 	error = ilo_map_device(pdev, ilo_hw);
804 	if (error)
805 		goto free_regions;
806 
807 	pci_set_drvdata(pdev, ilo_hw);
808 	clear_device(ilo_hw);
809 
810 	error = request_irq(pdev->irq, ilo_isr, IRQF_SHARED, "hpilo", ilo_hw);
811 	if (error)
812 		goto unmap;
813 
814 	ilo_enable_interrupts(ilo_hw);
815 
816 	cdev_init(&ilo_hw->cdev, &ilo_fops);
817 	ilo_hw->cdev.owner = THIS_MODULE;
818 	start = devnum * max_ccb;
819 	error = cdev_add(&ilo_hw->cdev, MKDEV(ilo_major, start), max_ccb);
820 	if (error) {
821 		dev_err(&pdev->dev, "Could not add cdev\n");
822 		goto remove_isr;
823 	}
824 
825 	for (minor = 0 ; minor < max_ccb; minor++) {
826 		struct device *dev;
827 		dev = device_create(ilo_class, &pdev->dev,
828 				    MKDEV(ilo_major, minor), NULL,
829 				    "hpilo!d%dccb%d", devnum, minor);
830 		if (IS_ERR(dev))
831 			dev_err(&pdev->dev, "Could not create files\n");
832 	}
833 
834 	return 0;
835 remove_isr:
836 	ilo_disable_interrupts(ilo_hw);
837 	free_irq(pdev->irq, ilo_hw);
838 unmap:
839 	ilo_unmap_device(pdev, ilo_hw);
840 free_regions:
841 	pci_release_regions(pdev);
842 disable:
843 /*	pci_disable_device(pdev);  see comment in ilo_remove */
844 free:
845 	kfree(ilo_hw);
846 out:
847 	ilo_hwdev[devnum] = 0;
848 	return error;
849 }
850 
851 static struct pci_device_id ilo_devices[] = {
852 	{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB204) },
853 	{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3307) },
854 	{ }
855 };
856 MODULE_DEVICE_TABLE(pci, ilo_devices);
857 
858 static struct pci_driver ilo_driver = {
859 	.name 	  = ILO_NAME,
860 	.id_table = ilo_devices,
861 	.probe 	  = ilo_probe,
862 	.remove   = ilo_remove,
863 };
864 
865 static int __init ilo_init(void)
866 {
867 	int error;
868 	dev_t dev;
869 
870 	ilo_class = class_create(THIS_MODULE, "iLO");
871 	if (IS_ERR(ilo_class)) {
872 		error = PTR_ERR(ilo_class);
873 		goto out;
874 	}
875 
876 	error = alloc_chrdev_region(&dev, 0, MAX_OPEN, ILO_NAME);
877 	if (error)
878 		goto class_destroy;
879 
880 	ilo_major = MAJOR(dev);
881 
882 	error =	pci_register_driver(&ilo_driver);
883 	if (error)
884 		goto chr_remove;
885 
886 	return 0;
887 chr_remove:
888 	unregister_chrdev_region(dev, MAX_OPEN);
889 class_destroy:
890 	class_destroy(ilo_class);
891 out:
892 	return error;
893 }
894 
895 static void __exit ilo_exit(void)
896 {
897 	pci_unregister_driver(&ilo_driver);
898 	unregister_chrdev_region(MKDEV(ilo_major, 0), MAX_OPEN);
899 	class_destroy(ilo_class);
900 }
901 
902 MODULE_VERSION("1.4.1");
903 MODULE_ALIAS(ILO_NAME);
904 MODULE_DESCRIPTION(ILO_NAME);
905 MODULE_AUTHOR("David Altobelli <david.altobelli@hpe.com>");
906 MODULE_LICENSE("GPL v2");
907 
908 module_param(max_ccb, uint, 0444);
909 MODULE_PARM_DESC(max_ccb, "Maximum number of HP iLO channels to attach (8-24)(default=16)");
910 
911 module_init(ilo_init);
912 module_exit(ilo_exit);
913