drivers/sbus/char/jsflash.c

   1 /*
   2  * drivers/sbus/char/jsflash.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds    (drivers/char/mem.c)
   5  *  Copyright (C) 1997  Eddie C. Dost           (drivers/sbus/char/flash.c)
   6  *  Copyright (C) 1997-2000 Pavel Machek <pavel@ucw.cz>   (drivers/block/nbd.c)
   7  *  Copyright (C) 1999-2000 Pete Zaitcev
   8  *
   9  * This driver is used to program OS into a Flash SIMM on
  10  * Krups and Espresso platforms.
  11  *
  12  * TODO: do not allow erase/programming if file systems are mounted.
  13  * TODO: Erase/program both banks of a 8MB SIMM.
  14  *
  15  * It is anticipated that programming an OS Flash will be a routine
  16  * procedure. In the same time it is exeedingly dangerous because
  17  * a user can program its OBP flash with OS image and effectively
  18  * kill the machine.
  19  *
  20  * This driver uses an interface different from Eddie's flash.c
  21  * as a silly safeguard.
  22  *
  23  * XXX The flash.c manipulates page caching characteristics in a certain
  24  * dubious way; also it assumes that remap_pfn_range() can remap
  25  * PCI bus locations, which may be false. ioremap() must be used
  26  * instead. We should discuss this.
  27  */
  28
  29 #include <linux/module.h>
  30 #include <linux/types.h>
  31 #include <linux/errno.h>
  32 #include <linux/miscdevice.h>
  33 #include <linux/slab.h>
  34 #include <linux/fcntl.h>
  35 #include <linux/poll.h>
  36 #include <linux/init.h>
  37 #include <linux/string.h>
  38 #include <linux/smp_lock.h>
  39 #include <linux/genhd.h>
  40 #include <linux/blkdev.h>
  41
  42 #define MAJOR_NR        JSFD_MAJOR
  43
  44 #include <asm/uaccess.h>
  45 #include <asm/pgtable.h>
  46 #include <asm/io.h>
  47 #include <asm/pcic.h>
  48 #include <asm/oplib.h>
  49
  50 #include <asm/jsflash.h>                /* ioctl arguments. <linux/> ?? */
  51 #define JSFIDSZ         (sizeof(struct jsflash_ident_arg))
  52 #define JSFPRGSZ        (sizeof(struct jsflash_program_arg))
  53
  54 /*
  55  * Our device numbers have no business in system headers.
  56  * The only thing a user knows is the device name /dev/jsflash.
  57  *
  58  * Block devices are laid out like this:
  59  *   minor+0    - Bootstrap, for 8MB SIMM 0x20400000[0x800000]
  60  *   minor+1    - Filesystem to mount, normally 0x20400400[0x7ffc00]
  61  *   minor+2    - Whole flash area for any case... 0x20000000[0x01000000]
  62  * Total 3 minors per flash device.
  63  *
  64  * It is easier to have static size vectors, so we define
  65  * a total minor range JSF_MAX, which must cover all minors.
  66  */
  67 /* character device */
  68 #define JSF_MINOR       178     /* 178 is registered with hpa */
  69 /* block device */
  70 #define JSF_MAX          3      /* 3 minors wasted total so far. */
  71 #define JSF_NPART        3      /* 3 minors per flash device */
  72 #define JSF_PART_BITS    2      /* 2 bits of minors to cover JSF_NPART */
  73 #define JSF_PART_MASK    0x3    /* 2 bits mask */
  74
  75 /*
  76  * Access functions.
  77  * We could ioremap(), but it's easier this way.
  78  */
  79 static unsigned int jsf_inl(unsigned long addr)
  80 {
  81         unsigned long retval;
  82
  83         __asm__ __volatile__("lda [%1] %2, %0\n\t" :
  84                                 "=r" (retval) :
  85                                 "r" (addr), "i" (ASI_M_BYPASS));
  86         return retval;
  87 }
  88
  89 static void jsf_outl(unsigned long addr, __u32 data)
  90 {
  91
  92         __asm__ __volatile__("sta %0, [%1] %2\n\t" : :
  93                                 "r" (data), "r" (addr), "i" (ASI_M_BYPASS) :
  94                                 "memory");
  95 }
  96
  97 /*
  98  * soft carrier
  99  */
 100
 101 struct jsfd_part {
 102         unsigned long dbase;
 103         unsigned long dsize;
 104 };
 105
 106 struct jsflash {
 107         unsigned long base;
 108         unsigned long size;
 109         unsigned long busy;             /* In use? */
 110         struct jsflash_ident_arg id;
 111         /* int mbase; */                /* Minor base, typically zero */
 112         struct jsfd_part dv[JSF_NPART];
 113 };
 114
 115 /*
 116  * We do not map normal memory or obio as a safety precaution.
 117  * But offsets are real, for ease of userland programming.
 118  */
 119 #define JSF_BASE_TOP    0x30000000
 120 #define JSF_BASE_ALL    0x20000000
 121
 122 #define JSF_BASE_JK     0x20400000
 123
 124 /*
 125  */
 126 static struct gendisk *jsfd_disk[JSF_MAX];
 127
 128 /*
 129  * Let's pretend we may have several of these...
 130  */
 131 static struct jsflash jsf0;
 132
 133 /*
 134  * Wait for AMD to finish its embedded algorithm.
 135  * We use the Toggle bit DQ6 (0x40) because it does not
 136  * depend on the data value as /DATA bit DQ7 does.
 137  *
 138  * XXX Do we need any timeout here? So far it never hanged, beware broken hw.
 139  */
 140 static void jsf_wait(unsigned long p) {
 141         unsigned int x1, x2;
 142
 143         for (;;) {
 144                 x1 = jsf_inl(p);
 145                 x2 = jsf_inl(p);
 146                 if ((x1 & 0x40404040) == (x2 & 0x40404040)) return;
 147         }
 148 }
 149
 150 /*
 151  * Programming will only work if Flash is clean,
 152  * we leave it to the programmer application.
 153  *
 154  * AMD must be programmed one byte at a time;
 155  * thus, Simple Tech SIMM must be written 4 bytes at a time.
 156  *
 157  * Write waits for the chip to become ready after the write
 158  * was finished. This is done so that application would read
 159  * consistent data after the write is done.
 160  */
 161 static void jsf_write4(unsigned long fa, u32 data) {
 162
 163         jsf_outl(fa, 0xAAAAAAAA);               /* Unlock 1 Write 1 */
 164         jsf_outl(fa, 0x55555555);               /* Unlock 1 Write 2 */
 165         jsf_outl(fa, 0xA0A0A0A0);               /* Byte Program */
 166         jsf_outl(fa, data);
 167
 168         jsf_wait(fa);
 169 }
 170
 171 /*
 172  */
 173 static void jsfd_read(char *buf, unsigned long p, size_t togo) {
 174         union byte4 {
 175                 char s[4];
 176                 unsigned int n;
 177         } b;
 178
 179         while (togo >= 4) {
 180                 togo -= 4;
 181                 b.n = jsf_inl(p);
 182                 memcpy(buf, b.s, 4);
 183                 p += 4;
 184                 buf += 4;
 185         }
 186 }
 187
 188 static void jsfd_do_request(request_queue_t *q)
 189 {
 190         struct request *req;
 191
 192         while ((req = elv_next_request(q)) != NULL) {
 193                 struct jsfd_part *jdp = req->rq_disk->private_data;
 194                 unsigned long offset = req->sector << 9;
 195                 size_t len = req->current_nr_sectors << 9;
 196
 197                 if ((offset + len) > jdp->dsize) {
 198                         end_request(req, 0);
 199                         continue;
 200                 }
 201
 202                 if (rq_data_dir(req) != READ) {
 203                         printk(KERN_ERR "jsfd: write\n");
 204                         end_request(req, 0);
 205                         continue;
 206                 }
 207
 208                 if ((jdp->dbase & 0xff000000) != 0x20000000) {
 209                         printk(KERN_ERR "jsfd: bad base %x\n", (int)jdp->dbase);
 210                         end_request(req, 0);
 211                         continue;
 212                 }
 213
 214                 jsfd_read(req->buffer, jdp->dbase + offset, len);
 215
 216                 end_request(req, 1);
 217         }
 218 }
 219
 220 /*
 221  * The memory devices use the full 32/64 bits of the offset, and so we cannot
 222  * check against negative addresses: they are ok. The return value is weird,
 223  * though, in that case (0).
 224  *
 225  * also note that seeking relative to the "end of file" isn't supported:
 226  * it has no meaning, so it returns -EINVAL.
 227  */
 228 static loff_t jsf_lseek(struct file * file, loff_t offset, int orig)
 229 {
 230         loff_t ret;
 231
 232         lock_kernel();
 233         switch (orig) {
 234                 case 0:
 235                         file->f_pos = offset;
 236                         ret = file->f_pos;
 237                         break;
 238                 case 1:
 239                         file->f_pos += offset;
 240                         ret = file->f_pos;
 241                         break;
 242                 default:
 243                         ret = -EINVAL;
 244         }
 245         unlock_kernel();
 246         return ret;
 247 }
 248
 249 /*
 250  * OS SIMM Cannot be read in other size but a 32bits word.
 251  */
 252 static ssize_t jsf_read(struct file * file, char * buf,
 253     size_t togo, loff_t *ppos)
 254 {
 255         unsigned long p = *ppos;
 256         char *tmp = buf;
 257
 258         union byte4 {
 259                 char s[4];
 260                 unsigned int n;
 261         } b;
 262
 263         if (p < JSF_BASE_ALL || p >= JSF_BASE_TOP) {
 264                 return 0;
 265         }
 266
 267         if ((p + togo) < p      /* wrap */
 268            || (p + togo) >= JSF_BASE_TOP) {
 269                 togo = JSF_BASE_TOP - p;
 270         }
 271
 272         if (p < JSF_BASE_ALL && togo != 0) {
 273 #if 0 /* __bzero XXX */
 274                 size_t x = JSF_BASE_ALL - p;
 275                 if (x > togo) x = togo;
 276                 clear_user(tmp, x);
 277                 tmp += x;
 278                 p += x;
 279                 togo -= x;
 280 #else
 281                 /*
 282                  * Implementation of clear_user() calls __bzero
 283                  * without regard to modversions,
 284                  * so we cannot build a module.
 285                  */
 286                 return 0;
 287 #endif
 288         }
 289
 290         while (togo >= 4) {
 291                 togo -= 4;
 292                 b.n = jsf_inl(p);
 293                 if (copy_to_user(tmp, b.s, 4))
 294                         return -EFAULT;
 295                 tmp += 4;
 296                 p += 4;
 297         }
 298
 299         /*
 300          * XXX Small togo may remain if 1 byte is ordered.
 301          * It would be nice if we did a word size read and unpacked it.
 302          */
 303
 304         *ppos = p;
 305         return tmp-buf;
 306 }
 307
 308 static ssize_t jsf_write(struct file * file, const char * buf,
 309     size_t count, loff_t *ppos)
 310 {
 311         return -ENOSPC;
 312 }
 313
 314 /*
 315  */
 316 static int jsf_ioctl_erase(unsigned long arg)
 317 {
 318         unsigned long p;
 319
 320         /* p = jsf0.base;       hits wrong bank */
 321         p = 0x20400000;
 322
 323         jsf_outl(p, 0xAAAAAAAA);                /* Unlock 1 Write 1 */
 324         jsf_outl(p, 0x55555555);                /* Unlock 1 Write 2 */
 325         jsf_outl(p, 0x80808080);                /* Erase setup */
 326         jsf_outl(p, 0xAAAAAAAA);                /* Unlock 2 Write 1 */
 327         jsf_outl(p, 0x55555555);                /* Unlock 2 Write 2 */
 328         jsf_outl(p, 0x10101010);                /* Chip erase */
 329
 330 #if 0
 331         /*
 332          * This code is ok, except that counter based timeout
 333          * has no place in this world. Let's just drop timeouts...
 334          */
 335         {
 336                 int i;
 337                 __u32 x;
 338                 for (i = 0; i < 1000000; i++) {
 339                         x = jsf_inl(p);
 340                         if ((x & 0x80808080) == 0x80808080) break;
 341                 }
 342                 if ((x & 0x80808080) != 0x80808080) {
 343                         printk("jsf0: erase timeout with 0x%08x\n", x);
 344                 } else {
 345                         printk("jsf0: erase done with 0x%08x\n", x);
 346                 }
 347         }
 348 #else
 349         jsf_wait(p);
 350 #endif
 351
 352         return 0;
 353 }
 354
 355 /*
 356  * Program a block of flash.
 357  * Very simple because we can do it byte by byte anyway.
 358  */
 359 static int jsf_ioctl_program(unsigned long arg)
 360 {
 361         struct jsflash_program_arg abuf;
 362         char *uptr;
 363         unsigned long p;
 364         unsigned int togo;
 365         union {
 366                 unsigned int n;
 367                 char s[4];
 368         } b;
 369
 370         if (copy_from_user(&abuf, (char *)arg, JSFPRGSZ))
 371                 return -EFAULT;
 372         p = abuf.off;
 373         togo = abuf.size;
 374         if ((togo & 3) || (p & 3)) return -EINVAL;
 375
 376         uptr = (char *) (unsigned long) abuf.data;
 377         while (togo != 0) {
 378                 togo -= 4;
 379                 if (copy_from_user(&b.s[0], uptr, 4))
 380                         return -EFAULT;
 381                 jsf_write4(p, b.n);
 382                 p += 4;
 383                 uptr += 4;
 384         }
 385
 386         return 0;
 387 }
 388
 389 static int jsf_ioctl(struct inode *inode, struct file *f, unsigned int cmd,
 390     unsigned long arg)
 391 {
 392         int error = -ENOTTY;
 393
 394         if (!capable(CAP_SYS_ADMIN))
 395                 return -EPERM;
 396         switch (cmd) {
 397         case JSFLASH_IDENT:
 398                 if (copy_to_user((void *)arg, &jsf0.id, JSFIDSZ))
 399                         return -EFAULT;
 400                 break;
 401         case JSFLASH_ERASE:
 402                 error = jsf_ioctl_erase(arg);
 403                 break;
 404         case JSFLASH_PROGRAM:
 405                 error = jsf_ioctl_program(arg);
 406                 break;
 407         }
 408
 409         return error;
 410 }
 411
 412 static int jsf_mmap(struct file * file, struct vm_area_struct * vma)
 413 {
 414         return -ENXIO;
 415 }
 416
 417 static int jsf_open(struct inode * inode, struct file * filp)
 418 {
 419
 420         if (jsf0.base == 0) return -ENXIO;
 421         if (test_and_set_bit(0, (void *)&jsf0.busy) != 0)
 422                 return -EBUSY;
 423
 424         return 0;       /* XXX What security? */
 425 }
 426
 427 static int jsf_release(struct inode *inode, struct file *file)
 428 {
 429         jsf0.busy = 0;
 430         return 0;
 431 }
 432
 433 static struct file_operations jsf_fops = {
 434         .owner =        THIS_MODULE,
 435         .llseek =       jsf_lseek,
 436         .read =         jsf_read,
 437         .write =        jsf_write,
 438         .ioctl =        jsf_ioctl,
 439         .mmap =         jsf_mmap,
 440         .open =         jsf_open,
 441         .release =      jsf_release,
 442 };
 443
 444 static struct miscdevice jsf_dev = { JSF_MINOR, "jsflash", &jsf_fops };
 445
 446 static struct block_device_operations jsfd_fops = {
 447         .owner =        THIS_MODULE,
 448 };
 449
 450 static int jsflash_init(void)
 451 {
 452         int rc;
 453         struct jsflash *jsf;
 454         int node;
 455         char banner[128];
 456         struct linux_prom_registers reg0;
 457
 458         node = prom_getchild(prom_root_node);
 459         node = prom_searchsiblings(node, "flash-memory");
 460         if (node != 0 && node != -1) {
 461                 if (prom_getproperty(node, "reg",
 462                     (char *)&reg0, sizeof(reg0)) == -1) {
 463                         printk("jsflash: no \"reg\" property\n");
 464                         return -ENXIO;
 465                 }
 466                 if (reg0.which_io != 0) {
 467                         printk("jsflash: bus number nonzero: 0x%x:%x\n",
 468                             reg0.which_io, reg0.phys_addr);
 469                         return -ENXIO;
 470                 }
 471                 /*
 472                  * Flash may be somewhere else, for instance on Ebus.
 473                  * So, don't do the following check for IIep flash space.
 474                  */
 475 #if 0
 476                 if ((reg0.phys_addr >> 24) != 0x20) {
 477                         printk("jsflash: suspicious address: 0x%x:%x\n",
 478                             reg0.which_io, reg0.phys_addr);
 479                         return -ENXIO;
 480                 }
 481 #endif
 482                 if ((int)reg0.reg_size <= 0) {
 483                         printk("jsflash: bad size 0x%x\n", (int)reg0.reg_size);
 484                         return -ENXIO;
 485                 }
 486         } else {
 487                 /* XXX Remove this code once PROLL ID12 got widespread */
 488                 printk("jsflash: no /flash-memory node, use PROLL >= 12\n");
 489                 prom_getproperty(prom_root_node, "banner-name", banner, 128);
 490                 if (strcmp (banner, "JavaStation-NC") != 0 &&
 491                     strcmp (banner, "JavaStation-E") != 0) {
 492                         return -ENXIO;
 493                 }
 494                 reg0.which_io = 0;
 495                 reg0.phys_addr = 0x20400000;
 496                 reg0.reg_size  = 0x00800000;
 497         }
 498
 499         /* Let us be really paranoid for modifications to probing code. */
 500         /* extern enum sparc_cpu sparc_cpu_model; */ /* in <asm/system.h> */
 501         if (sparc_cpu_model != sun4m) {
 502                 /* We must be on sun4m because we use MMU Bypass ASI. */
 503                 return -ENXIO;
 504         }
 505
 506         if (jsf0.base == 0) {
 507                 jsf = &jsf0;
 508
 509                 jsf->base = reg0.phys_addr;
 510                 jsf->size = reg0.reg_size;
 511
 512                 /* XXX Redo the userland interface. */
 513                 jsf->id.off = JSF_BASE_ALL;
 514                 jsf->id.size = 0x01000000;      /* 16M - all segments */
 515                 strcpy(jsf->id.name, "Krups_all");
 516
 517                 jsf->dv[0].dbase = jsf->base;
 518                 jsf->dv[0].dsize = jsf->size;
 519                 jsf->dv[1].dbase = jsf->base + 1024;
 520                 jsf->dv[1].dsize = jsf->size - 1024;
 521                 jsf->dv[2].dbase = JSF_BASE_ALL;
 522                 jsf->dv[2].dsize = 0x01000000;
 523
 524                 printk("Espresso Flash @0x%lx [%d MB]\n", jsf->base,
 525                     (int) (jsf->size / (1024*1024)));
 526         }
 527
 528         if ((rc = misc_register(&jsf_dev)) != 0) {
 529                 printk(KERN_ERR "jsf: unable to get misc minor %d\n",
 530                     JSF_MINOR);
 531                 jsf0.base = 0;
 532                 return rc;
 533         }
 534
 535         return 0;
 536 }
 537
 538 static struct request_queue *jsf_queue;
 539
 540 static int jsfd_init(void)
 541 {
 542         static DEFINE_SPINLOCK(lock);
 543         struct jsflash *jsf;
 544         struct jsfd_part *jdp;
 545         int err;
 546         int i;
 547
 548         if (jsf0.base == 0)
 549                 return -ENXIO;
 550
 551         err = -ENOMEM;
 552         for (i = 0; i < JSF_MAX; i++) {
 553                 struct gendisk *disk = alloc_disk(1);
 554                 if (!disk)
 555                         goto out;
 556                 jsfd_disk[i] = disk;
 557         }
 558
 559         if (register_blkdev(JSFD_MAJOR, "jsfd")) {
 560                 err = -EIO;
 561                 goto out;
 562         }
 563
 564         jsf_queue = blk_init_queue(jsfd_do_request, &lock);
 565         if (!jsf_queue) {
 566                 err = -ENOMEM;
 567                 unregister_blkdev(JSFD_MAJOR, "jsfd");
 568                 goto out;
 569         }
 570
 571         for (i = 0; i < JSF_MAX; i++) {
 572                 struct gendisk *disk = jsfd_disk[i];
 573                 if ((i & JSF_PART_MASK) >= JSF_NPART) continue;
 574                 jsf = &jsf0;    /* actually, &jsfv[i >> JSF_PART_BITS] */
 575                 jdp = &jsf->dv[i&JSF_PART_MASK];
 576
 577                 disk->major = JSFD_MAJOR;
 578                 disk->first_minor = i;
 579                 sprintf(disk->disk_name, "jsfd%d", i);
 580                 disk->fops = &jsfd_fops;
 581                 set_capacity(disk, jdp->dsize >> 9);
 582                 disk->private_data = jdp;
 583                 disk->queue = jsf_queue;
 584                 add_disk(disk);
 585                 set_disk_ro(disk, 1);
 586         }
 587         return 0;
 588 out:
 589         while (i--)
 590                 put_disk(jsfd_disk[i]);
 591         return err;
 592 }
 593
 594 MODULE_LICENSE("GPL");
 595
 596 static int __init jsflash_init_module(void) {
 597         int rc;
 598
 599         if ((rc = jsflash_init()) == 0) {
 600                 jsfd_init();
 601                 return 0;
 602         }
 603         return rc;
 604 }
 605
 606 static void __exit jsflash_cleanup_module(void)
 607 {
 608         int i;
 609
 610         for (i = 0; i < JSF_MAX; i++) {
 611                 if ((i & JSF_PART_MASK) >= JSF_NPART) continue;
 612                 del_gendisk(jsfd_disk[i]);
 613                 put_disk(jsfd_disk[i]);
 614         }
 615         if (jsf0.busy)
 616                 printk("jsf0: cleaning busy unit\n");
 617         jsf0.base = 0;
 618         jsf0.busy = 0;
 619
 620         misc_deregister(&jsf_dev);
 621         if (unregister_blkdev(JSFD_MAJOR, "jsfd") != 0)
 622                 printk("jsfd: cleanup_module failed\n");
 623         blk_cleanup_queue(jsf_queue);
 624 }
 625
 626 module_init(jsflash_init_module);
 627 module_exit(jsflash_cleanup_module);