xref: /openbmc/linux/drivers/misc/hpilo.c (revision 9b93eb47)
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 	pci_free_consistent(pdev, data->dma_size, data->dma_va, data->dma_pa);
260 }
261 
262 static int ilo_ccb_setup(struct ilo_hwinfo *hw, struct ccb_data *data, int slot)
263 {
264 	char *dma_va;
265 	dma_addr_t dma_pa;
266 	struct ccb *driver_ccb, *ilo_ccb;
267 
268 	driver_ccb = &data->driver_ccb;
269 	ilo_ccb = &data->ilo_ccb;
270 
271 	data->dma_size = 2 * fifo_sz(NR_QENTRY) +
272 			 2 * desc_mem_sz(NR_QENTRY) +
273 			 ILO_START_ALIGN + ILO_CACHE_SZ;
274 
275 	data->dma_va = pci_alloc_consistent(hw->ilo_dev, data->dma_size,
276 					    &data->dma_pa);
277 	if (!data->dma_va)
278 		return -ENOMEM;
279 
280 	dma_va = (char *)data->dma_va;
281 	dma_pa = data->dma_pa;
282 
283 	memset(dma_va, 0, data->dma_size);
284 
285 	dma_va = (char *)roundup((unsigned long)dma_va, ILO_START_ALIGN);
286 	dma_pa = roundup(dma_pa, ILO_START_ALIGN);
287 
288 	/*
289 	 * Create two ccb's, one with virt addrs, one with phys addrs.
290 	 * Copy the phys addr ccb to device shared mem.
291 	 */
292 	ctrl_setup(driver_ccb, NR_QENTRY, L2_QENTRY_SZ);
293 	ctrl_setup(ilo_ccb, NR_QENTRY, L2_QENTRY_SZ);
294 
295 	fifo_setup(dma_va, NR_QENTRY);
296 	driver_ccb->ccb_u1.send_fifobar = dma_va + FIFOHANDLESIZE;
297 	ilo_ccb->ccb_u1.send_fifobar_pa = dma_pa + FIFOHANDLESIZE;
298 	dma_va += fifo_sz(NR_QENTRY);
299 	dma_pa += fifo_sz(NR_QENTRY);
300 
301 	dma_va = (char *)roundup((unsigned long)dma_va, ILO_CACHE_SZ);
302 	dma_pa = roundup(dma_pa, ILO_CACHE_SZ);
303 
304 	fifo_setup(dma_va, NR_QENTRY);
305 	driver_ccb->ccb_u3.recv_fifobar = dma_va + FIFOHANDLESIZE;
306 	ilo_ccb->ccb_u3.recv_fifobar_pa = dma_pa + FIFOHANDLESIZE;
307 	dma_va += fifo_sz(NR_QENTRY);
308 	dma_pa += fifo_sz(NR_QENTRY);
309 
310 	driver_ccb->ccb_u2.send_desc = dma_va;
311 	ilo_ccb->ccb_u2.send_desc_pa = dma_pa;
312 	dma_pa += desc_mem_sz(NR_QENTRY);
313 	dma_va += desc_mem_sz(NR_QENTRY);
314 
315 	driver_ccb->ccb_u4.recv_desc = dma_va;
316 	ilo_ccb->ccb_u4.recv_desc_pa = dma_pa;
317 
318 	driver_ccb->channel = slot;
319 	ilo_ccb->channel = slot;
320 
321 	driver_ccb->ccb_u5.db_base = hw->db_vaddr + (slot << L2_DB_SIZE);
322 	ilo_ccb->ccb_u5.db_base = NULL; /* hw ccb's doorbell is not used */
323 
324 	return 0;
325 }
326 
327 static void ilo_ccb_open(struct ilo_hwinfo *hw, struct ccb_data *data, int slot)
328 {
329 	int pkt_id, pkt_sz;
330 	struct ccb *driver_ccb = &data->driver_ccb;
331 
332 	/* copy the ccb with physical addrs to device memory */
333 	data->mapped_ccb = (struct ccb __iomem *)
334 				(hw->ram_vaddr + (slot * ILOHW_CCB_SZ));
335 	memcpy_toio(data->mapped_ccb, &data->ilo_ccb, sizeof(struct ccb));
336 
337 	/* put packets on the send and receive queues */
338 	pkt_sz = 0;
339 	for (pkt_id = 0; pkt_id < NR_QENTRY; pkt_id++) {
340 		ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, pkt_sz);
341 		doorbell_set(driver_ccb);
342 	}
343 
344 	pkt_sz = desc_mem_sz(1);
345 	for (pkt_id = 0; pkt_id < NR_QENTRY; pkt_id++)
346 		ilo_pkt_enqueue(hw, driver_ccb, RECVQ, pkt_id, pkt_sz);
347 
348 	/* the ccb is ready to use */
349 	doorbell_clr(driver_ccb);
350 }
351 
352 static int ilo_ccb_verify(struct ilo_hwinfo *hw, struct ccb_data *data)
353 {
354 	int pkt_id, i;
355 	struct ccb *driver_ccb = &data->driver_ccb;
356 
357 	/* make sure iLO is really handling requests */
358 	for (i = MAX_WAIT; i > 0; i--) {
359 		if (ilo_pkt_dequeue(hw, driver_ccb, SENDQ, &pkt_id, NULL, NULL))
360 			break;
361 		udelay(WAIT_TIME);
362 	}
363 
364 	if (i == 0) {
365 		dev_err(&hw->ilo_dev->dev, "Open could not dequeue a packet\n");
366 		return -EBUSY;
367 	}
368 
369 	ilo_pkt_enqueue(hw, driver_ccb, SENDQ, pkt_id, 0);
370 	doorbell_set(driver_ccb);
371 	return 0;
372 }
373 
374 static inline int is_channel_reset(struct ccb *ccb)
375 {
376 	/* check for this particular channel needing a reset */
377 	return FIFOBARTOHANDLE(ccb->ccb_u1.send_fifobar)->reset;
378 }
379 
380 static inline void set_channel_reset(struct ccb *ccb)
381 {
382 	/* set a flag indicating this channel needs a reset */
383 	FIFOBARTOHANDLE(ccb->ccb_u1.send_fifobar)->reset = 1;
384 }
385 
386 static inline int get_device_outbound(struct ilo_hwinfo *hw)
387 {
388 	return ioread32(&hw->mmio_vaddr[DB_OUT]);
389 }
390 
391 static inline int is_db_reset(int db_out)
392 {
393 	return db_out & (1 << DB_RESET);
394 }
395 
396 static inline int is_device_reset(struct ilo_hwinfo *hw)
397 {
398 	/* check for global reset condition */
399 	return is_db_reset(get_device_outbound(hw));
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(sizeof(*data), GFP_KERNEL);
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 
698 	/* map the memory mapped i/o registers */
699 	hw->mmio_vaddr = pci_iomap(pdev, 1, 0);
700 	if (hw->mmio_vaddr == NULL) {
701 		dev_err(&pdev->dev, "Error mapping mmio\n");
702 		goto out;
703 	}
704 
705 	/* map the adapter shared memory region */
706 	if (pdev->subsystem_device == 0x00E4) {
707 		bar = 5;
708 		/* Last 8k is reserved for CCBs */
709 		off = pci_resource_len(pdev, bar) - 0x2000;
710 	} else {
711 		bar = 2;
712 		off = 0;
713 	}
714 	hw->ram_vaddr = pci_iomap_range(pdev, bar, off, max_ccb * ILOHW_CCB_SZ);
715 	if (hw->ram_vaddr == NULL) {
716 		dev_err(&pdev->dev, "Error mapping shared mem\n");
717 		goto mmio_free;
718 	}
719 
720 	/* map the doorbell aperture */
721 	hw->db_vaddr = pci_iomap(pdev, 3, max_ccb * ONE_DB_SIZE);
722 	if (hw->db_vaddr == NULL) {
723 		dev_err(&pdev->dev, "Error mapping doorbell\n");
724 		goto ram_free;
725 	}
726 
727 	return 0;
728 ram_free:
729 	pci_iounmap(pdev, hw->ram_vaddr);
730 mmio_free:
731 	pci_iounmap(pdev, hw->mmio_vaddr);
732 out:
733 	return -ENOMEM;
734 }
735 
736 static void ilo_remove(struct pci_dev *pdev)
737 {
738 	int i, minor;
739 	struct ilo_hwinfo *ilo_hw = pci_get_drvdata(pdev);
740 
741 	if (!ilo_hw)
742 		return;
743 
744 	clear_device(ilo_hw);
745 
746 	minor = MINOR(ilo_hw->cdev.dev);
747 	for (i = minor; i < minor + max_ccb; i++)
748 		device_destroy(ilo_class, MKDEV(ilo_major, i));
749 
750 	cdev_del(&ilo_hw->cdev);
751 	ilo_disable_interrupts(ilo_hw);
752 	free_irq(pdev->irq, ilo_hw);
753 	ilo_unmap_device(pdev, ilo_hw);
754 	pci_release_regions(pdev);
755 	/*
756 	 * pci_disable_device(pdev) used to be here. But this PCI device has
757 	 * two functions with interrupt lines connected to a single pin. The
758 	 * other one is a USB host controller. So when we disable the PIN here
759 	 * e.g. by rmmod hpilo, the controller stops working. It is because
760 	 * the interrupt link is disabled in ACPI since it is not refcounted
761 	 * yet. See acpi_pci_link_free_irq called from acpi_pci_irq_disable.
762 	 */
763 	kfree(ilo_hw);
764 	ilo_hwdev[(minor / max_ccb)] = 0;
765 }
766 
767 static int ilo_probe(struct pci_dev *pdev,
768 			       const struct pci_device_id *ent)
769 {
770 	int devnum, minor, start, error = 0;
771 	struct ilo_hwinfo *ilo_hw;
772 
773 	if (pci_match_id(ilo_blacklist, pdev)) {
774 		dev_dbg(&pdev->dev, "Not supported on this device\n");
775 		return -ENODEV;
776 	}
777 
778 	if (max_ccb > MAX_CCB)
779 		max_ccb = MAX_CCB;
780 	else if (max_ccb < MIN_CCB)
781 		max_ccb = MIN_CCB;
782 
783 	/* find a free range for device files */
784 	for (devnum = 0; devnum < MAX_ILO_DEV; devnum++) {
785 		if (ilo_hwdev[devnum] == 0) {
786 			ilo_hwdev[devnum] = 1;
787 			break;
788 		}
789 	}
790 
791 	if (devnum == MAX_ILO_DEV) {
792 		dev_err(&pdev->dev, "Error finding free device\n");
793 		return -ENODEV;
794 	}
795 
796 	/* track global allocations for this device */
797 	error = -ENOMEM;
798 	ilo_hw = kzalloc(sizeof(*ilo_hw), GFP_KERNEL);
799 	if (!ilo_hw)
800 		goto out;
801 
802 	ilo_hw->ilo_dev = pdev;
803 	spin_lock_init(&ilo_hw->alloc_lock);
804 	spin_lock_init(&ilo_hw->fifo_lock);
805 	spin_lock_init(&ilo_hw->open_lock);
806 
807 	error = pci_enable_device(pdev);
808 	if (error)
809 		goto free;
810 
811 	pci_set_master(pdev);
812 
813 	error = pci_request_regions(pdev, ILO_NAME);
814 	if (error)
815 		goto disable;
816 
817 	error = ilo_map_device(pdev, ilo_hw);
818 	if (error)
819 		goto free_regions;
820 
821 	pci_set_drvdata(pdev, ilo_hw);
822 	clear_device(ilo_hw);
823 
824 	error = request_irq(pdev->irq, ilo_isr, IRQF_SHARED, "hpilo", ilo_hw);
825 	if (error)
826 		goto unmap;
827 
828 	ilo_enable_interrupts(ilo_hw);
829 
830 	cdev_init(&ilo_hw->cdev, &ilo_fops);
831 	ilo_hw->cdev.owner = THIS_MODULE;
832 	start = devnum * max_ccb;
833 	error = cdev_add(&ilo_hw->cdev, MKDEV(ilo_major, start), max_ccb);
834 	if (error) {
835 		dev_err(&pdev->dev, "Could not add cdev\n");
836 		goto remove_isr;
837 	}
838 
839 	for (minor = 0 ; minor < max_ccb; minor++) {
840 		struct device *dev;
841 		dev = device_create(ilo_class, &pdev->dev,
842 				    MKDEV(ilo_major, minor), NULL,
843 				    "hpilo!d%dccb%d", devnum, minor);
844 		if (IS_ERR(dev))
845 			dev_err(&pdev->dev, "Could not create files\n");
846 	}
847 
848 	return 0;
849 remove_isr:
850 	ilo_disable_interrupts(ilo_hw);
851 	free_irq(pdev->irq, ilo_hw);
852 unmap:
853 	ilo_unmap_device(pdev, ilo_hw);
854 free_regions:
855 	pci_release_regions(pdev);
856 disable:
857 /*	pci_disable_device(pdev);  see comment in ilo_remove */
858 free:
859 	kfree(ilo_hw);
860 out:
861 	ilo_hwdev[devnum] = 0;
862 	return error;
863 }
864 
865 static const struct pci_device_id ilo_devices[] = {
866 	{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB204) },
867 	{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3307) },
868 	{ }
869 };
870 MODULE_DEVICE_TABLE(pci, ilo_devices);
871 
872 static struct pci_driver ilo_driver = {
873 	.name 	  = ILO_NAME,
874 	.id_table = ilo_devices,
875 	.probe 	  = ilo_probe,
876 	.remove   = ilo_remove,
877 };
878 
879 static int __init ilo_init(void)
880 {
881 	int error;
882 	dev_t dev;
883 
884 	ilo_class = class_create(THIS_MODULE, "iLO");
885 	if (IS_ERR(ilo_class)) {
886 		error = PTR_ERR(ilo_class);
887 		goto out;
888 	}
889 
890 	error = alloc_chrdev_region(&dev, 0, MAX_OPEN, ILO_NAME);
891 	if (error)
892 		goto class_destroy;
893 
894 	ilo_major = MAJOR(dev);
895 
896 	error =	pci_register_driver(&ilo_driver);
897 	if (error)
898 		goto chr_remove;
899 
900 	return 0;
901 chr_remove:
902 	unregister_chrdev_region(dev, MAX_OPEN);
903 class_destroy:
904 	class_destroy(ilo_class);
905 out:
906 	return error;
907 }
908 
909 static void __exit ilo_exit(void)
910 {
911 	pci_unregister_driver(&ilo_driver);
912 	unregister_chrdev_region(MKDEV(ilo_major, 0), MAX_OPEN);
913 	class_destroy(ilo_class);
914 }
915 
916 MODULE_VERSION("1.5.0");
917 MODULE_ALIAS(ILO_NAME);
918 MODULE_DESCRIPTION(ILO_NAME);
919 MODULE_AUTHOR("David Altobelli <david.altobelli@hpe.com>");
920 MODULE_LICENSE("GPL v2");
921 
922 module_param(max_ccb, uint, 0444);
923 MODULE_PARM_DESC(max_ccb, "Maximum number of HP iLO channels to attach (8-24)(default=16)");
924 
925 module_init(ilo_init);
926 module_exit(ilo_exit);
927