xref: /openbmc/linux/drivers/misc/hpilo.c (revision b737eecd)
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 struct class *ilo_class;
29 static unsigned int ilo_major;
30 static unsigned int max_ccb = 16;
31 static char ilo_hwdev[MAX_ILO_DEV];
32 static const struct pci_device_id ilo_blacklist[] = {
33 	/* auxiliary iLO */
34 	{PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3307, PCI_VENDOR_ID_HP, 0x1979)},
35 	/* CL */
36 	{PCI_DEVICE_SUB(PCI_VENDOR_ID_HP, 0x3307, PCI_VENDOR_ID_HP_3PAR, 0x0289)},
37 	{}
38 };
39 
40 static inline int get_entry_id(int entry)
41 {
42 	return (entry & ENTRY_MASK_DESCRIPTOR) >> ENTRY_BITPOS_DESCRIPTOR;
43 }
44 
45 static inline int get_entry_len(int entry)
46 {
47 	return ((entry & ENTRY_MASK_QWORDS) >> ENTRY_BITPOS_QWORDS) << 3;
48 }
49 
50 static inline int mk_entry(int id, int len)
51 {
52 	int qlen = len & 7 ? (len >> 3) + 1 : len >> 3;
53 	return id << ENTRY_BITPOS_DESCRIPTOR | qlen << ENTRY_BITPOS_QWORDS;
54 }
55 
56 static inline int desc_mem_sz(int nr_entry)
57 {
58 	return nr_entry << L2_QENTRY_SZ;
59 }
60 
61 /*
62  * FIFO queues, shared with hardware.
63  *
64  * If a queue has empty slots, an entry is added to the queue tail,
65  * and that entry is marked as occupied.
66  * Entries can be dequeued from the head of the list, when the device
67  * has marked the entry as consumed.
68  *
69  * Returns true on successful queue/dequeue, false on failure.
70  */
71 static int fifo_enqueue(struct ilo_hwinfo *hw, char *fifobar, int entry)
72 {
73 	struct fifo *fifo_q = FIFOBARTOHANDLE(fifobar);
74 	unsigned long flags;
75 	int ret = 0;
76 
77 	spin_lock_irqsave(&hw->fifo_lock, flags);
78 	if (!(fifo_q->fifobar[(fifo_q->tail + 1) & fifo_q->imask]
79 	      & ENTRY_MASK_O)) {
80 		fifo_q->fifobar[fifo_q->tail & fifo_q->imask] |=
81 				(entry & ENTRY_MASK_NOSTATE) | fifo_q->merge;
82 		fifo_q->tail += 1;
83 		ret = 1;
84 	}
85 	spin_unlock_irqrestore(&hw->fifo_lock, flags);
86 
87 	return ret;
88 }
89 
90 static int fifo_dequeue(struct ilo_hwinfo *hw, char *fifobar, int *entry)
91 {
92 	struct fifo *fifo_q = FIFOBARTOHANDLE(fifobar);
93 	unsigned long flags;
94 	int ret = 0;
95 	u64 c;
96 
97 	spin_lock_irqsave(&hw->fifo_lock, flags);
98 	c = fifo_q->fifobar[fifo_q->head & fifo_q->imask];
99 	if (c & ENTRY_MASK_C) {
100 		if (entry)
101 			*entry = c & ENTRY_MASK_NOSTATE;
102 
103 		fifo_q->fifobar[fifo_q->head & fifo_q->imask] =
104 							(c | ENTRY_MASK) + 1;
105 		fifo_q->head += 1;
106 		ret = 1;
107 	}
108 	spin_unlock_irqrestore(&hw->fifo_lock, flags);
109 
110 	return ret;
111 }
112 
113 static int fifo_check_recv(struct ilo_hwinfo *hw, char *fifobar)
114 {
115 	struct fifo *fifo_q = FIFOBARTOHANDLE(fifobar);
116 	unsigned long flags;
117 	int ret = 0;
118 	u64 c;
119 
120 	spin_lock_irqsave(&hw->fifo_lock, flags);
121 	c = fifo_q->fifobar[fifo_q->head & fifo_q->imask];
122 	if (c & ENTRY_MASK_C)
123 		ret = 1;
124 	spin_unlock_irqrestore(&hw->fifo_lock, flags);
125 
126 	return ret;
127 }
128 
129 static int ilo_pkt_enqueue(struct ilo_hwinfo *hw, struct ccb *ccb,
130 			   int dir, int id, int len)
131 {
132 	char *fifobar;
133 	int entry;
134 
135 	if (dir == SENDQ)
136 		fifobar = ccb->ccb_u1.send_fifobar;
137 	else
138 		fifobar = ccb->ccb_u3.recv_fifobar;
139 
140 	entry = mk_entry(id, len);
141 	return fifo_enqueue(hw, fifobar, entry);
142 }
143 
144 static int ilo_pkt_dequeue(struct ilo_hwinfo *hw, struct ccb *ccb,
145 			   int dir, int *id, int *len, void **pkt)
146 {
147 	char *fifobar, *desc;
148 	int entry = 0, pkt_id = 0;
149 	int ret;
150 
151 	if (dir == SENDQ) {
152 		fifobar = ccb->ccb_u1.send_fifobar;
153 		desc = ccb->ccb_u2.send_desc;
154 	} else {
155 		fifobar = ccb->ccb_u3.recv_fifobar;
156 		desc = ccb->ccb_u4.recv_desc;
157 	}
158 
159 	ret = fifo_dequeue(hw, fifobar, &entry);
160 	if (ret) {
161 		pkt_id = get_entry_id(entry);
162 		if (id)
163 			*id = pkt_id;
164 		if (len)
165 			*len = get_entry_len(entry);
166 		if (pkt)
167 			*pkt = (void *)(desc + desc_mem_sz(pkt_id));
168 	}
169 
170 	return ret;
171 }
172 
173 static int ilo_pkt_recv(struct ilo_hwinfo *hw, struct ccb *ccb)
174 {
175 	char *fifobar = ccb->ccb_u3.recv_fifobar;
176 
177 	return fifo_check_recv(hw, fifobar);
178 }
179 
180 static inline void doorbell_set(struct ccb *ccb)
181 {
182 	iowrite8(1, ccb->ccb_u5.db_base);
183 }
184 
185 static inline void doorbell_clr(struct ccb *ccb)
186 {
187 	iowrite8(2, ccb->ccb_u5.db_base);
188 }
189 
190 static inline int ctrl_set(int l2sz, int idxmask, int desclim)
191 {
192 	int active = 0, go = 1;
193 	return l2sz << CTRL_BITPOS_L2SZ |
194 	       idxmask << CTRL_BITPOS_FIFOINDEXMASK |
195 	       desclim << CTRL_BITPOS_DESCLIMIT |
196 	       active << CTRL_BITPOS_A |
197 	       go << CTRL_BITPOS_G;
198 }
199 
200 static void ctrl_setup(struct ccb *ccb, int nr_desc, int l2desc_sz)
201 {
202 	/* for simplicity, use the same parameters for send and recv ctrls */
203 	ccb->send_ctrl = ctrl_set(l2desc_sz, nr_desc-1, nr_desc-1);
204 	ccb->recv_ctrl = ctrl_set(l2desc_sz, nr_desc-1, nr_desc-1);
205 }
206 
207 static inline int fifo_sz(int nr_entry)
208 {
209 	/* size of a fifo is determined by the number of entries it contains */
210 	return nr_entry * sizeof(u64) + FIFOHANDLESIZE;
211 }
212 
213 static void fifo_setup(void *base_addr, int nr_entry)
214 {
215 	struct fifo *fifo_q = base_addr;
216 	int i;
217 
218 	/* set up an empty fifo */
219 	fifo_q->head = 0;
220 	fifo_q->tail = 0;
221 	fifo_q->reset = 0;
222 	fifo_q->nrents = nr_entry;
223 	fifo_q->imask = nr_entry - 1;
224 	fifo_q->merge = ENTRY_MASK_O;
225 
226 	for (i = 0; i < nr_entry; i++)
227 		fifo_q->fifobar[i] = 0;
228 }
229 
230 static void ilo_ccb_close(struct pci_dev *pdev, struct ccb_data *data)
231 {
232 	struct ccb *driver_ccb = &data->driver_ccb;
233 	struct ccb __iomem *device_ccb = data->mapped_ccb;
234 	int retries;
235 
236 	/* complicated dance to tell the hw we are stopping */
237 	doorbell_clr(driver_ccb);
238 	iowrite32(ioread32(&device_ccb->send_ctrl) & ~(1 << CTRL_BITPOS_G),
239 		  &device_ccb->send_ctrl);
240 	iowrite32(ioread32(&device_ccb->recv_ctrl) & ~(1 << CTRL_BITPOS_G),
241 		  &device_ccb->recv_ctrl);
242 
243 	/* give iLO some time to process stop request */
244 	for (retries = MAX_WAIT; retries > 0; retries--) {
245 		doorbell_set(driver_ccb);
246 		udelay(WAIT_TIME);
247 		if (!(ioread32(&device_ccb->send_ctrl) & (1 << CTRL_BITPOS_A))
248 		    &&
249 		    !(ioread32(&device_ccb->recv_ctrl) & (1 << CTRL_BITPOS_A)))
250 			break;
251 	}
252 	if (retries == 0)
253 		dev_err(&pdev->dev, "Closing, but controller still active\n");
254 
255 	/* clear the hw ccb */
256 	memset_io(device_ccb, 0, sizeof(struct ccb));
257 
258 	/* free resources used to back send/recv queues */
259 	dma_free_coherent(&pdev->dev, data->dma_size, data->dma_va,
260 			  data->dma_pa);
261 }
262 
263 static int ilo_ccb_setup(struct ilo_hwinfo *hw, struct ccb_data *data, int slot)
264 {
265 	char *dma_va;
266 	dma_addr_t dma_pa;
267 	struct ccb *driver_ccb, *ilo_ccb;
268 
269 	driver_ccb = &data->driver_ccb;
270 	ilo_ccb = &data->ilo_ccb;
271 
272 	data->dma_size = 2 * fifo_sz(NR_QENTRY) +
273 			 2 * desc_mem_sz(NR_QENTRY) +
274 			 ILO_START_ALIGN + ILO_CACHE_SZ;
275 
276 	data->dma_va = dma_alloc_coherent(&hw->ilo_dev->dev, data->dma_size,
277 					  &data->dma_pa, GFP_ATOMIC);
278 	if (!data->dma_va)
279 		return -ENOMEM;
280 
281 	dma_va = (char *)data->dma_va;
282 	dma_pa = data->dma_pa;
283 
284 	dma_va = (char *)roundup((unsigned long)dma_va, ILO_START_ALIGN);
285 	dma_pa = roundup(dma_pa, ILO_START_ALIGN);
286 
287 	/*
288 	 * Create two ccb's, one with virt addrs, one with phys addrs.
289 	 * Copy the phys addr ccb to device shared mem.
290 	 */
291 	ctrl_setup(driver_ccb, NR_QENTRY, L2_QENTRY_SZ);
292 	ctrl_setup(ilo_ccb, NR_QENTRY, L2_QENTRY_SZ);
293 
294 	fifo_setup(dma_va, NR_QENTRY);
295 	driver_ccb->ccb_u1.send_fifobar = dma_va + FIFOHANDLESIZE;
296 	ilo_ccb->ccb_u1.send_fifobar_pa = dma_pa + FIFOHANDLESIZE;
297 	dma_va += fifo_sz(NR_QENTRY);
298 	dma_pa += fifo_sz(NR_QENTRY);
299 
300 	dma_va = (char *)roundup((unsigned long)dma_va, ILO_CACHE_SZ);
301 	dma_pa = roundup(dma_pa, ILO_CACHE_SZ);
302 
303 	fifo_setup(dma_va, NR_QENTRY);
304 	driver_ccb->ccb_u3.recv_fifobar = dma_va + FIFOHANDLESIZE;
305 	ilo_ccb->ccb_u3.recv_fifobar_pa = dma_pa + FIFOHANDLESIZE;
306 	dma_va += fifo_sz(NR_QENTRY);
307 	dma_pa += fifo_sz(NR_QENTRY);
308 
309 	driver_ccb->ccb_u2.send_desc = dma_va;
310 	ilo_ccb->ccb_u2.send_desc_pa = dma_pa;
311 	dma_pa += desc_mem_sz(NR_QENTRY);
312 	dma_va += desc_mem_sz(NR_QENTRY);
313 
314 	driver_ccb->ccb_u4.recv_desc = dma_va;
315 	ilo_ccb->ccb_u4.recv_desc_pa = dma_pa;
316 
317 	driver_ccb->channel = slot;
318 	ilo_ccb->channel = slot;
319 
320 	driver_ccb->ccb_u5.db_base = hw->db_vaddr + (slot << L2_DB_SIZE);
321 	ilo_ccb->ccb_u5.db_base = NULL; /* hw ccb's doorbell is not used */
322 
323 	return 0;
324 }
325 
326 static void ilo_ccb_open(struct ilo_hwinfo *hw, struct ccb_data *data, int slot)
327 {
328 	int pkt_id, pkt_sz;
329 	struct ccb *driver_ccb = &data->driver_ccb;
330 
331 	/* copy the ccb with physical addrs to device memory */
332 	data->mapped_ccb = (struct ccb __iomem *)
333 				(hw->ram_vaddr + (slot * ILOHW_CCB_SZ));
334 	memcpy_toio(data->mapped_ccb, &data->ilo_ccb, sizeof(struct ccb));
335 
336 	/* put packets on the send and receive queues */
337 	pkt_sz = 0;
338 	for (pkt_id = 0; pkt_id < NR_QENTRY; pkt_id++) {
339 		ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, pkt_sz);
340 		doorbell_set(driver_ccb);
341 	}
342 
343 	pkt_sz = desc_mem_sz(1);
344 	for (pkt_id = 0; pkt_id < NR_QENTRY; pkt_id++)
345 		ilo_pkt_enqueue(hw, driver_ccb, RECVQ, pkt_id, pkt_sz);
346 
347 	/* the ccb is ready to use */
348 	doorbell_clr(driver_ccb);
349 }
350 
351 static int ilo_ccb_verify(struct ilo_hwinfo *hw, struct ccb_data *data)
352 {
353 	int pkt_id, i;
354 	struct ccb *driver_ccb = &data->driver_ccb;
355 
356 	/* make sure iLO is really handling requests */
357 	for (i = MAX_WAIT; i > 0; i--) {
358 		if (ilo_pkt_dequeue(hw, driver_ccb, SENDQ, &pkt_id, NULL, NULL))
359 			break;
360 		udelay(WAIT_TIME);
361 	}
362 
363 	if (i == 0) {
364 		dev_err(&hw->ilo_dev->dev, "Open could not dequeue a packet\n");
365 		return -EBUSY;
366 	}
367 
368 	ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, 0);
369 	doorbell_set(driver_ccb);
370 	return 0;
371 }
372 
373 static inline int is_channel_reset(struct ccb *ccb)
374 {
375 	/* check for this particular channel needing a reset */
376 	return FIFOBARTOHANDLE(ccb->ccb_u1.send_fifobar)->reset;
377 }
378 
379 static inline void set_channel_reset(struct ccb *ccb)
380 {
381 	/* set a flag indicating this channel needs a reset */
382 	FIFOBARTOHANDLE(ccb->ccb_u1.send_fifobar)->reset = 1;
383 }
384 
385 static inline int get_device_outbound(struct ilo_hwinfo *hw)
386 {
387 	return ioread32(&hw->mmio_vaddr[DB_OUT]);
388 }
389 
390 static inline int is_db_reset(int db_out)
391 {
392 	return db_out & (1 << DB_RESET);
393 }
394 
395 static inline int is_device_reset(struct ilo_hwinfo *hw)
396 {
397 	/* check for global reset condition */
398 	return is_db_reset(get_device_outbound(hw));
399 }
400 
401 static inline void clear_pending_db(struct ilo_hwinfo *hw, int clr)
402 {
403 	iowrite32(clr, &hw->mmio_vaddr[DB_OUT]);
404 }
405 
406 static inline void clear_device(struct ilo_hwinfo *hw)
407 {
408 	/* clear the device (reset bits, pending channel entries) */
409 	clear_pending_db(hw, -1);
410 }
411 
412 static inline void ilo_enable_interrupts(struct ilo_hwinfo *hw)
413 {
414 	iowrite8(ioread8(&hw->mmio_vaddr[DB_IRQ]) | 1, &hw->mmio_vaddr[DB_IRQ]);
415 }
416 
417 static inline void ilo_disable_interrupts(struct ilo_hwinfo *hw)
418 {
419 	iowrite8(ioread8(&hw->mmio_vaddr[DB_IRQ]) & ~1,
420 		 &hw->mmio_vaddr[DB_IRQ]);
421 }
422 
423 static void ilo_set_reset(struct ilo_hwinfo *hw)
424 {
425 	int slot;
426 
427 	/*
428 	 * Mapped memory is zeroed on ilo reset, so set a per ccb flag
429 	 * to indicate that this ccb needs to be closed and reopened.
430 	 */
431 	for (slot = 0; slot < max_ccb; slot++) {
432 		if (!hw->ccb_alloc[slot])
433 			continue;
434 		set_channel_reset(&hw->ccb_alloc[slot]->driver_ccb);
435 	}
436 }
437 
438 static ssize_t ilo_read(struct file *fp, char __user *buf,
439 			size_t len, loff_t *off)
440 {
441 	int err, found, cnt, pkt_id, pkt_len;
442 	struct ccb_data *data = fp->private_data;
443 	struct ccb *driver_ccb = &data->driver_ccb;
444 	struct ilo_hwinfo *hw = data->ilo_hw;
445 	void *pkt;
446 
447 	if (is_channel_reset(driver_ccb)) {
448 		/*
449 		 * If the device has been reset, applications
450 		 * need to close and reopen all ccbs.
451 		 */
452 		return -ENODEV;
453 	}
454 
455 	/*
456 	 * This function is to be called when data is expected
457 	 * in the channel, and will return an error if no packet is found
458 	 * during the loop below.  The sleep/retry logic is to allow
459 	 * applications to call read() immediately post write(),
460 	 * and give iLO some time to process the sent packet.
461 	 */
462 	cnt = 20;
463 	do {
464 		/* look for a received packet */
465 		found = ilo_pkt_dequeue(hw, driver_ccb, RECVQ, &pkt_id,
466 					&pkt_len, &pkt);
467 		if (found)
468 			break;
469 		cnt--;
470 		msleep(100);
471 	} while (!found && cnt);
472 
473 	if (!found)
474 		return -EAGAIN;
475 
476 	/* only copy the length of the received packet */
477 	if (pkt_len < len)
478 		len = pkt_len;
479 
480 	err = copy_to_user(buf, pkt, len);
481 
482 	/* return the received packet to the queue */
483 	ilo_pkt_enqueue(hw, driver_ccb, RECVQ, pkt_id, desc_mem_sz(1));
484 
485 	return err ? -EFAULT : len;
486 }
487 
488 static ssize_t ilo_write(struct file *fp, const char __user *buf,
489 			 size_t len, loff_t *off)
490 {
491 	int err, pkt_id, pkt_len;
492 	struct ccb_data *data = fp->private_data;
493 	struct ccb *driver_ccb = &data->driver_ccb;
494 	struct ilo_hwinfo *hw = data->ilo_hw;
495 	void *pkt;
496 
497 	if (is_channel_reset(driver_ccb))
498 		return -ENODEV;
499 
500 	/* get a packet to send the user command */
501 	if (!ilo_pkt_dequeue(hw, driver_ccb, SENDQ, &pkt_id, &pkt_len, &pkt))
502 		return -EBUSY;
503 
504 	/* limit the length to the length of the packet */
505 	if (pkt_len < len)
506 		len = pkt_len;
507 
508 	/* on failure, set the len to 0 to return empty packet to the device */
509 	err = copy_from_user(pkt, buf, len);
510 	if (err)
511 		len = 0;
512 
513 	/* send the packet */
514 	ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, len);
515 	doorbell_set(driver_ccb);
516 
517 	return err ? -EFAULT : len;
518 }
519 
520 static __poll_t ilo_poll(struct file *fp, poll_table *wait)
521 {
522 	struct ccb_data *data = fp->private_data;
523 	struct ccb *driver_ccb = &data->driver_ccb;
524 
525 	poll_wait(fp, &data->ccb_waitq, wait);
526 
527 	if (is_channel_reset(driver_ccb))
528 		return EPOLLERR;
529 	else if (ilo_pkt_recv(data->ilo_hw, driver_ccb))
530 		return EPOLLIN | EPOLLRDNORM;
531 
532 	return 0;
533 }
534 
535 static int ilo_close(struct inode *ip, struct file *fp)
536 {
537 	int slot;
538 	struct ccb_data *data;
539 	struct ilo_hwinfo *hw;
540 	unsigned long flags;
541 
542 	slot = iminor(ip) % max_ccb;
543 	hw = container_of(ip->i_cdev, struct ilo_hwinfo, cdev);
544 
545 	spin_lock(&hw->open_lock);
546 
547 	if (hw->ccb_alloc[slot]->ccb_cnt == 1) {
548 
549 		data = fp->private_data;
550 
551 		spin_lock_irqsave(&hw->alloc_lock, flags);
552 		hw->ccb_alloc[slot] = NULL;
553 		spin_unlock_irqrestore(&hw->alloc_lock, flags);
554 
555 		ilo_ccb_close(hw->ilo_dev, data);
556 
557 		kfree(data);
558 	} else
559 		hw->ccb_alloc[slot]->ccb_cnt--;
560 
561 	spin_unlock(&hw->open_lock);
562 
563 	return 0;
564 }
565 
566 static int ilo_open(struct inode *ip, struct file *fp)
567 {
568 	int slot, error;
569 	struct ccb_data *data;
570 	struct ilo_hwinfo *hw;
571 	unsigned long flags;
572 
573 	slot = iminor(ip) % max_ccb;
574 	hw = container_of(ip->i_cdev, struct ilo_hwinfo, cdev);
575 
576 	/* new ccb allocation */
577 	data = kzalloc(sizeof(*data), GFP_KERNEL);
578 	if (!data)
579 		return -ENOMEM;
580 
581 	spin_lock(&hw->open_lock);
582 
583 	/* each fd private_data holds sw/hw view of ccb */
584 	if (hw->ccb_alloc[slot] == NULL) {
585 		/* create a channel control block for this minor */
586 		error = ilo_ccb_setup(hw, data, slot);
587 		if (error) {
588 			kfree(data);
589 			goto out;
590 		}
591 
592 		data->ccb_cnt = 1;
593 		data->ccb_excl = fp->f_flags & O_EXCL;
594 		data->ilo_hw = hw;
595 		init_waitqueue_head(&data->ccb_waitq);
596 
597 		/* write the ccb to hw */
598 		spin_lock_irqsave(&hw->alloc_lock, flags);
599 		ilo_ccb_open(hw, data, slot);
600 		hw->ccb_alloc[slot] = data;
601 		spin_unlock_irqrestore(&hw->alloc_lock, flags);
602 
603 		/* make sure the channel is functional */
604 		error = ilo_ccb_verify(hw, data);
605 		if (error) {
606 
607 			spin_lock_irqsave(&hw->alloc_lock, flags);
608 			hw->ccb_alloc[slot] = NULL;
609 			spin_unlock_irqrestore(&hw->alloc_lock, flags);
610 
611 			ilo_ccb_close(hw->ilo_dev, data);
612 
613 			kfree(data);
614 			goto out;
615 		}
616 
617 	} else {
618 		kfree(data);
619 		if (fp->f_flags & O_EXCL || hw->ccb_alloc[slot]->ccb_excl) {
620 			/*
621 			 * The channel exists, and either this open
622 			 * or a previous open of this channel wants
623 			 * exclusive access.
624 			 */
625 			error = -EBUSY;
626 		} else {
627 			hw->ccb_alloc[slot]->ccb_cnt++;
628 			error = 0;
629 		}
630 	}
631 out:
632 	spin_unlock(&hw->open_lock);
633 
634 	if (!error)
635 		fp->private_data = hw->ccb_alloc[slot];
636 
637 	return error;
638 }
639 
640 static const struct file_operations ilo_fops = {
641 	.owner		= THIS_MODULE,
642 	.read		= ilo_read,
643 	.write		= ilo_write,
644 	.poll		= ilo_poll,
645 	.open 		= ilo_open,
646 	.release 	= ilo_close,
647 	.llseek		= noop_llseek,
648 };
649 
650 static irqreturn_t ilo_isr(int irq, void *data)
651 {
652 	struct ilo_hwinfo *hw = data;
653 	int pending, i;
654 
655 	spin_lock(&hw->alloc_lock);
656 
657 	/* check for ccbs which have data */
658 	pending = get_device_outbound(hw);
659 	if (!pending) {
660 		spin_unlock(&hw->alloc_lock);
661 		return IRQ_NONE;
662 	}
663 
664 	if (is_db_reset(pending)) {
665 		/* wake up all ccbs if the device was reset */
666 		pending = -1;
667 		ilo_set_reset(hw);
668 	}
669 
670 	for (i = 0; i < max_ccb; i++) {
671 		if (!hw->ccb_alloc[i])
672 			continue;
673 		if (pending & (1 << i))
674 			wake_up_interruptible(&hw->ccb_alloc[i]->ccb_waitq);
675 	}
676 
677 	/* clear the device of the channels that have been handled */
678 	clear_pending_db(hw, pending);
679 
680 	spin_unlock(&hw->alloc_lock);
681 
682 	return IRQ_HANDLED;
683 }
684 
685 static void ilo_unmap_device(struct pci_dev *pdev, struct ilo_hwinfo *hw)
686 {
687 	pci_iounmap(pdev, hw->db_vaddr);
688 	pci_iounmap(pdev, hw->ram_vaddr);
689 	pci_iounmap(pdev, hw->mmio_vaddr);
690 }
691 
692 static int ilo_map_device(struct pci_dev *pdev, struct ilo_hwinfo *hw)
693 {
694 	int bar;
695 	unsigned long off;
696 
697 	/* map the memory mapped i/o registers */
698 	hw->mmio_vaddr = pci_iomap(pdev, 1, 0);
699 	if (hw->mmio_vaddr == NULL) {
700 		dev_err(&pdev->dev, "Error mapping mmio\n");
701 		goto out;
702 	}
703 
704 	/* map the adapter shared memory region */
705 	if (pdev->subsystem_device == 0x00E4) {
706 		bar = 5;
707 		/* Last 8k is reserved for CCBs */
708 		off = pci_resource_len(pdev, bar) - 0x2000;
709 	} else {
710 		bar = 2;
711 		off = 0;
712 	}
713 	hw->ram_vaddr = pci_iomap_range(pdev, bar, off, max_ccb * ILOHW_CCB_SZ);
714 	if (hw->ram_vaddr == NULL) {
715 		dev_err(&pdev->dev, "Error mapping shared mem\n");
716 		goto mmio_free;
717 	}
718 
719 	/* map the doorbell aperture */
720 	hw->db_vaddr = pci_iomap(pdev, 3, max_ccb * ONE_DB_SIZE);
721 	if (hw->db_vaddr == NULL) {
722 		dev_err(&pdev->dev, "Error mapping doorbell\n");
723 		goto ram_free;
724 	}
725 
726 	return 0;
727 ram_free:
728 	pci_iounmap(pdev, hw->ram_vaddr);
729 mmio_free:
730 	pci_iounmap(pdev, hw->mmio_vaddr);
731 out:
732 	return -ENOMEM;
733 }
734 
735 static void ilo_remove(struct pci_dev *pdev)
736 {
737 	int i, minor;
738 	struct ilo_hwinfo *ilo_hw = pci_get_drvdata(pdev);
739 
740 	if (!ilo_hw)
741 		return;
742 
743 	clear_device(ilo_hw);
744 
745 	minor = MINOR(ilo_hw->cdev.dev);
746 	for (i = minor; i < minor + max_ccb; i++)
747 		device_destroy(ilo_class, MKDEV(ilo_major, i));
748 
749 	cdev_del(&ilo_hw->cdev);
750 	ilo_disable_interrupts(ilo_hw);
751 	free_irq(pdev->irq, ilo_hw);
752 	ilo_unmap_device(pdev, ilo_hw);
753 	pci_release_regions(pdev);
754 	/*
755 	 * pci_disable_device(pdev) used to be here. But this PCI device has
756 	 * two functions with interrupt lines connected to a single pin. The
757 	 * other one is a USB host controller. So when we disable the PIN here
758 	 * e.g. by rmmod hpilo, the controller stops working. It is because
759 	 * the interrupt link is disabled in ACPI since it is not refcounted
760 	 * yet. See acpi_pci_link_free_irq called from acpi_pci_irq_disable.
761 	 */
762 	kfree(ilo_hw);
763 	ilo_hwdev[(minor / max_ccb)] = 0;
764 }
765 
766 static int ilo_probe(struct pci_dev *pdev,
767 			       const struct pci_device_id *ent)
768 {
769 	int devnum, minor, start, error = 0;
770 	struct ilo_hwinfo *ilo_hw;
771 
772 	if (pci_match_id(ilo_blacklist, pdev)) {
773 		dev_dbg(&pdev->dev, "Not supported on this device\n");
774 		return -ENODEV;
775 	}
776 
777 	if (max_ccb > MAX_CCB)
778 		max_ccb = MAX_CCB;
779 	else if (max_ccb < MIN_CCB)
780 		max_ccb = MIN_CCB;
781 
782 	/* find a free range for device files */
783 	for (devnum = 0; devnum < MAX_ILO_DEV; devnum++) {
784 		if (ilo_hwdev[devnum] == 0) {
785 			ilo_hwdev[devnum] = 1;
786 			break;
787 		}
788 	}
789 
790 	if (devnum == MAX_ILO_DEV) {
791 		dev_err(&pdev->dev, "Error finding free device\n");
792 		return -ENODEV;
793 	}
794 
795 	/* track global allocations for this device */
796 	error = -ENOMEM;
797 	ilo_hw = kzalloc(sizeof(*ilo_hw), GFP_KERNEL);
798 	if (!ilo_hw)
799 		goto out;
800 
801 	ilo_hw->ilo_dev = pdev;
802 	spin_lock_init(&ilo_hw->alloc_lock);
803 	spin_lock_init(&ilo_hw->fifo_lock);
804 	spin_lock_init(&ilo_hw->open_lock);
805 
806 	error = pci_enable_device(pdev);
807 	if (error)
808 		goto free;
809 
810 	pci_set_master(pdev);
811 
812 	error = pci_request_regions(pdev, ILO_NAME);
813 	if (error)
814 		goto disable;
815 
816 	error = ilo_map_device(pdev, ilo_hw);
817 	if (error)
818 		goto free_regions;
819 
820 	pci_set_drvdata(pdev, ilo_hw);
821 	clear_device(ilo_hw);
822 
823 	error = request_irq(pdev->irq, ilo_isr, IRQF_SHARED, "hpilo", ilo_hw);
824 	if (error)
825 		goto unmap;
826 
827 	ilo_enable_interrupts(ilo_hw);
828 
829 	cdev_init(&ilo_hw->cdev, &ilo_fops);
830 	ilo_hw->cdev.owner = THIS_MODULE;
831 	start = devnum * max_ccb;
832 	error = cdev_add(&ilo_hw->cdev, MKDEV(ilo_major, start), max_ccb);
833 	if (error) {
834 		dev_err(&pdev->dev, "Could not add cdev\n");
835 		goto remove_isr;
836 	}
837 
838 	for (minor = 0 ; minor < max_ccb; minor++) {
839 		struct device *dev;
840 		dev = device_create(ilo_class, &pdev->dev,
841 				    MKDEV(ilo_major, minor), NULL,
842 				    "hpilo!d%dccb%d", devnum, minor);
843 		if (IS_ERR(dev))
844 			dev_err(&pdev->dev, "Could not create files\n");
845 	}
846 
847 	return 0;
848 remove_isr:
849 	ilo_disable_interrupts(ilo_hw);
850 	free_irq(pdev->irq, ilo_hw);
851 unmap:
852 	ilo_unmap_device(pdev, ilo_hw);
853 free_regions:
854 	pci_release_regions(pdev);
855 disable:
856 /*	pci_disable_device(pdev);  see comment in ilo_remove */
857 free:
858 	kfree(ilo_hw);
859 out:
860 	ilo_hwdev[devnum] = 0;
861 	return error;
862 }
863 
864 static const struct pci_device_id ilo_devices[] = {
865 	{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB204) },
866 	{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3307) },
867 	{ }
868 };
869 MODULE_DEVICE_TABLE(pci, ilo_devices);
870 
871 static struct pci_driver ilo_driver = {
872 	.name 	  = ILO_NAME,
873 	.id_table = ilo_devices,
874 	.probe 	  = ilo_probe,
875 	.remove   = ilo_remove,
876 };
877 
878 static int __init ilo_init(void)
879 {
880 	int error;
881 	dev_t dev;
882 
883 	ilo_class = class_create(THIS_MODULE, "iLO");
884 	if (IS_ERR(ilo_class)) {
885 		error = PTR_ERR(ilo_class);
886 		goto out;
887 	}
888 
889 	error = alloc_chrdev_region(&dev, 0, MAX_OPEN, ILO_NAME);
890 	if (error)
891 		goto class_destroy;
892 
893 	ilo_major = MAJOR(dev);
894 
895 	error =	pci_register_driver(&ilo_driver);
896 	if (error)
897 		goto chr_remove;
898 
899 	return 0;
900 chr_remove:
901 	unregister_chrdev_region(dev, MAX_OPEN);
902 class_destroy:
903 	class_destroy(ilo_class);
904 out:
905 	return error;
906 }
907 
908 static void __exit ilo_exit(void)
909 {
910 	pci_unregister_driver(&ilo_driver);
911 	unregister_chrdev_region(MKDEV(ilo_major, 0), MAX_OPEN);
912 	class_destroy(ilo_class);
913 }
914 
915 MODULE_VERSION("1.5.0");
916 MODULE_ALIAS(ILO_NAME);
917 MODULE_DESCRIPTION(ILO_NAME);
918 MODULE_AUTHOR("David Altobelli <david.altobelli@hpe.com>");
919 MODULE_LICENSE("GPL v2");
920 
921 module_param(max_ccb, uint, 0444);
922 MODULE_PARM_DESC(max_ccb, "Maximum number of HP iLO channels to attach (8-24)(default=16)");
923 
924 module_init(ilo_init);
925 module_exit(ilo_exit);
926