drivers/misc/hpilo.c

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