arch/mips/jazz/jazzdma.c

   1 /*
   2  * Mips Jazz DMA controller support
   3  * Copyright (C) 1995, 1996 by Andreas Busse
   4  *
   5  * NOTE: Some of the argument checking could be removed when
   6  * things have settled down. Also, instead of returning 0xffffffff
   7  * on failure of vdma_alloc() one could leave page #0 unused
   8  * and return the more usual NULL pointer as logical address.
   9  */
  10 #include <linux/kernel.h>
  11 #include <linux/init.h>
  12 #include <linux/module.h>
  13 #include <linux/errno.h>
  14 #include <linux/mm.h>
  15 #include <linux/bootmem.h>
  16 #include <linux/spinlock.h>
  17 #include <asm/mipsregs.h>
  18 #include <asm/jazz.h>
  19 #include <asm/io.h>
  20 #include <asm/uaccess.h>
  21 #include <asm/dma.h>
  22 #include <asm/jazzdma.h>
  23 #include <asm/pgtable.h>
  24
  25 /*
  26  * Set this to one to enable additional vdma debug code.
  27  */
  28 #define CONF_DEBUG_VDMA 0
  29
  30 static unsigned long vdma_pagetable_start;
  31
  32 static spinlock_t vdma_lock = SPIN_LOCK_UNLOCKED;
  33
  34 /*
  35  * Debug stuff
  36  */
  37 #define vdma_debug     ((CONF_DEBUG_VDMA) ? debuglvl : 0)
  38
  39 static int debuglvl = 3;
  40
  41 /*
  42  * Initialize the pagetable with a one-to-one mapping of
  43  * the first 16 Mbytes of main memory and declare all
  44  * entries to be unused. Using this method will at least
  45  * allow some early device driver operations to work.
  46  */
  47 static inline void vdma_pgtbl_init(void)
  48 {
  49         VDMA_PGTBL_ENTRY *pgtbl = (VDMA_PGTBL_ENTRY *) vdma_pagetable_start;
  50         unsigned long paddr = 0;
  51         int i;
  52
  53         for (i = 0; i < VDMA_PGTBL_ENTRIES; i++) {
  54                 pgtbl[i].frame = paddr;
  55                 pgtbl[i].owner = VDMA_PAGE_EMPTY;
  56                 paddr += VDMA_PAGESIZE;
  57         }
  58 }
  59
  60 /*
  61  * Initialize the Jazz R4030 dma controller
  62  */
  63 void __init vdma_init(void)
  64 {
  65         /*
  66          * Allocate 32k of memory for DMA page tables.  This needs to be page
  67          * aligned and should be uncached to avoid cache flushing after every
  68          * update.
  69          */
  70         vdma_pagetable_start = alloc_bootmem_low_pages(VDMA_PGTBL_SIZE);
  71         if (!vdma_pagetable_start)
  72                 BUG();
  73         dma_cache_wback_inv(vdma_pagetable_start, VDMA_PGTBL_SIZE);
  74         vdma_pagetable_start = KSEG1ADDR(vdma_pagetable_start);
  75
  76         /*
  77          * Clear the R4030 translation table
  78          */
  79         vdma_pgtbl_init();
  80
  81         r4030_write_reg32(JAZZ_R4030_TRSTBL_BASE,
  82                           CPHYSADDR(vdma_pagetable_start));
  83         r4030_write_reg32(JAZZ_R4030_TRSTBL_LIM, VDMA_PGTBL_SIZE);
  84         r4030_write_reg32(JAZZ_R4030_TRSTBL_INV, 0);
  85
  86         printk("VDMA: R4030 DMA pagetables initialized.\n");
  87 }
  88
  89 /*
  90  * Allocate DMA pagetables using a simple first-fit algorithm
  91  */
  92 unsigned long vdma_alloc(unsigned long paddr, unsigned long size)
  93 {
  94         VDMA_PGTBL_ENTRY *entry = (VDMA_PGTBL_ENTRY *) vdma_pagetable_start;
  95         int first, last, pages, frame, i;
  96         unsigned long laddr, flags;
  97
  98         /* check arguments */
  99
 100         if (paddr > 0x1fffffff) {
 101                 if (vdma_debug)
 102                         printk("vdma_alloc: Invalid physical address: %08lx\n",
 103                                paddr);
 104                 return VDMA_ERROR;      /* invalid physical address */
 105         }
 106         if (size > 0x400000 || size == 0) {
 107                 if (vdma_debug)
 108                         printk("vdma_alloc: Invalid size: %08lx\n", size);
 109                 return VDMA_ERROR;      /* invalid physical address */
 110         }
 111
 112         spin_lock_irqsave(&vdma_lock, flags);
 113         /*
 114          * Find free chunk
 115          */
 116         pages = (size + 4095) >> 12;    /* no. of pages to allocate */
 117         first = 0;
 118         while (1) {
 119                 while (entry[first].owner != VDMA_PAGE_EMPTY &&
 120                        first < VDMA_PGTBL_ENTRIES) first++;
 121                 if (first + pages > VDMA_PGTBL_ENTRIES) {       /* nothing free */
 122                         spin_unlock_irqrestore(&vdma_lock, flags);
 123                         return VDMA_ERROR;
 124                 }
 125
 126                 last = first + 1;
 127                 while (entry[last].owner == VDMA_PAGE_EMPTY
 128                        && last - first < pages)
 129                         last++;
 130
 131                 if (last - first == pages)
 132                         break;  /* found */
 133         }
 134
 135         /*
 136          * Mark pages as allocated
 137          */
 138         laddr = (first << 12) + (paddr & (VDMA_PAGESIZE - 1));
 139         frame = paddr & ~(VDMA_PAGESIZE - 1);
 140
 141         for (i = first; i < last; i++) {
 142                 entry[i].frame = frame;
 143                 entry[i].owner = laddr;
 144                 frame += VDMA_PAGESIZE;
 145         }
 146
 147         /*
 148          * Update translation table and return logical start address
 149          */
 150         r4030_write_reg32(JAZZ_R4030_TRSTBL_INV, 0);
 151
 152         if (vdma_debug > 1)
 153                 printk("vdma_alloc: Allocated %d pages starting from %08lx\n",
 154                      pages, laddr);
 155
 156         if (vdma_debug > 2) {
 157                 printk("LADDR: ");
 158                 for (i = first; i < last; i++)
 159                         printk("%08x ", i << 12);
 160                 printk("\nPADDR: ");
 161                 for (i = first; i < last; i++)
 162                         printk("%08x ", entry[i].frame);
 163                 printk("\nOWNER: ");
 164                 for (i = first; i < last; i++)
 165                         printk("%08x ", entry[i].owner);
 166                 printk("\n");
 167         }
 168
 169         spin_unlock_irqrestore(&vdma_lock, flags);
 170
 171         return laddr;
 172 }
 173
 174 EXPORT_SYMBOL(vdma_alloc);
 175
 176 /*
 177  * Free previously allocated dma translation pages
 178  * Note that this does NOT change the translation table,
 179  * it just marks the free'd pages as unused!
 180  */
 181 int vdma_free(unsigned long laddr)
 182 {
 183         VDMA_PGTBL_ENTRY *pgtbl = (VDMA_PGTBL_ENTRY *) vdma_pagetable_start;
 184         int i;
 185
 186         i = laddr >> 12;
 187
 188         if (pgtbl[i].owner != laddr) {
 189                 printk
 190                     ("vdma_free: trying to free other's dma pages, laddr=%8lx\n",
 191                      laddr);
 192                 return -1;
 193         }
 194
 195         while (pgtbl[i].owner == laddr && i < VDMA_PGTBL_ENTRIES) {
 196                 pgtbl[i].owner = VDMA_PAGE_EMPTY;
 197                 i++;
 198         }
 199
 200         if (vdma_debug > 1)
 201                 printk("vdma_free: freed %ld pages starting from %08lx\n",
 202                        i - (laddr >> 12), laddr);
 203
 204         return 0;
 205 }
 206
 207 EXPORT_SYMBOL(vdma_free);
 208
 209 /*
 210  * Map certain page(s) to another physical address.
 211  * Caller must have allocated the page(s) before.
 212  */
 213 int vdma_remap(unsigned long laddr, unsigned long paddr, unsigned long size)
 214 {
 215         VDMA_PGTBL_ENTRY *pgtbl =
 216             (VDMA_PGTBL_ENTRY *) vdma_pagetable_start;
 217         int first, pages, npages;
 218
 219         if (laddr > 0xffffff) {
 220                 if (vdma_debug)
 221                         printk
 222                             ("vdma_map: Invalid logical address: %08lx\n",
 223                              laddr);
 224                 return -EINVAL; /* invalid logical address */
 225         }
 226         if (paddr > 0x1fffffff) {
 227                 if (vdma_debug)
 228                         printk
 229                             ("vdma_map: Invalid physical address: %08lx\n",
 230                              paddr);
 231                 return -EINVAL; /* invalid physical address */
 232         }
 233
 234         npages = pages =
 235             (((paddr & (VDMA_PAGESIZE - 1)) + size) >> 12) + 1;
 236         first = laddr >> 12;
 237         if (vdma_debug)
 238                 printk("vdma_remap: first=%x, pages=%x\n", first, pages);
 239         if (first + pages > VDMA_PGTBL_ENTRIES) {
 240                 if (vdma_debug)
 241                         printk("vdma_alloc: Invalid size: %08lx\n", size);
 242                 return -EINVAL;
 243         }
 244
 245         paddr &= ~(VDMA_PAGESIZE - 1);
 246         while (pages > 0 && first < VDMA_PGTBL_ENTRIES) {
 247                 if (pgtbl[first].owner != laddr) {
 248                         if (vdma_debug)
 249                                 printk("Trying to remap other's pages.\n");
 250                         return -EPERM;  /* not owner */
 251                 }
 252                 pgtbl[first].frame = paddr;
 253                 paddr += VDMA_PAGESIZE;
 254                 first++;
 255                 pages--;
 256         }
 257
 258         /*
 259          * Update translation table
 260          */
 261         r4030_write_reg32(JAZZ_R4030_TRSTBL_INV, 0);
 262
 263         if (vdma_debug > 2) {
 264                 int i;
 265                 pages = (((paddr & (VDMA_PAGESIZE - 1)) + size) >> 12) + 1;
 266                 first = laddr >> 12;
 267                 printk("LADDR: ");
 268                 for (i = first; i < first + pages; i++)
 269                         printk("%08x ", i << 12);
 270                 printk("\nPADDR: ");
 271                 for (i = first; i < first + pages; i++)
 272                         printk("%08x ", pgtbl[i].frame);
 273                 printk("\nOWNER: ");
 274                 for (i = first; i < first + pages; i++)
 275                         printk("%08x ", pgtbl[i].owner);
 276                 printk("\n");
 277         }
 278
 279         return 0;
 280 }
 281
 282 /*
 283  * Translate a physical address to a logical address.
 284  * This will return the logical address of the first
 285  * match.
 286  */
 287 unsigned long vdma_phys2log(unsigned long paddr)
 288 {
 289         int i;
 290         int frame;
 291         VDMA_PGTBL_ENTRY *pgtbl =
 292             (VDMA_PGTBL_ENTRY *) vdma_pagetable_start;
 293
 294         frame = paddr & ~(VDMA_PAGESIZE - 1);
 295
 296         for (i = 0; i < VDMA_PGTBL_ENTRIES; i++) {
 297                 if (pgtbl[i].frame == frame)
 298                         break;
 299         }
 300
 301         if (i == VDMA_PGTBL_ENTRIES)
 302                 return ~0UL;
 303
 304         return (i << 12) + (paddr & (VDMA_PAGESIZE - 1));
 305 }
 306
 307 /*
 308  * Translate a logical DMA address to a physical address
 309  */
 310 unsigned long vdma_log2phys(unsigned long laddr)
 311 {
 312         VDMA_PGTBL_ENTRY *pgtbl =
 313             (VDMA_PGTBL_ENTRY *) vdma_pagetable_start;
 314
 315         return pgtbl[laddr >> 12].frame + (laddr & (VDMA_PAGESIZE - 1));
 316 }
 317
 318 EXPORT_SYMBOL(vdma_log2phys);
 319
 320 /*
 321  * Print DMA statistics
 322  */
 323 void vdma_stats(void)
 324 {
 325         int i;
 326
 327         printk("vdma_stats: CONFIG: %08x\n",
 328                r4030_read_reg32(JAZZ_R4030_CONFIG));
 329         printk("R4030 translation table base: %08x\n",
 330                r4030_read_reg32(JAZZ_R4030_TRSTBL_BASE));
 331         printk("R4030 translation table limit: %08x\n",
 332                r4030_read_reg32(JAZZ_R4030_TRSTBL_LIM));
 333         printk("vdma_stats: INV_ADDR: %08x\n",
 334                r4030_read_reg32(JAZZ_R4030_INV_ADDR));
 335         printk("vdma_stats: R_FAIL_ADDR: %08x\n",
 336                r4030_read_reg32(JAZZ_R4030_R_FAIL_ADDR));
 337         printk("vdma_stats: M_FAIL_ADDR: %08x\n",
 338                r4030_read_reg32(JAZZ_R4030_M_FAIL_ADDR));
 339         printk("vdma_stats: IRQ_SOURCE: %08x\n",
 340                r4030_read_reg32(JAZZ_R4030_IRQ_SOURCE));
 341         printk("vdma_stats: I386_ERROR: %08x\n",
 342                r4030_read_reg32(JAZZ_R4030_I386_ERROR));
 343         printk("vdma_chnl_modes:   ");
 344         for (i = 0; i < 8; i++)
 345                 printk("%04x ",
 346                        (unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_MODE +
 347                                                    (i << 5)));
 348         printk("\n");
 349         printk("vdma_chnl_enables: ");
 350         for (i = 0; i < 8; i++)
 351                 printk("%04x ",
 352                        (unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 353                                                    (i << 5)));
 354         printk("\n");
 355 }
 356
 357 /*
 358  * DMA transfer functions
 359  */
 360
 361 /*
 362  * Enable a DMA channel. Also clear any error conditions.
 363  */
 364 void vdma_enable(int channel)
 365 {
 366         int status;
 367
 368         if (vdma_debug)
 369                 printk("vdma_enable: channel %d\n", channel);
 370
 371         /*
 372          * Check error conditions first
 373          */
 374         status = r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5));
 375         if (status & 0x400)
 376                 printk("VDMA: Channel %d: Address error!\n", channel);
 377         if (status & 0x200)
 378                 printk("VDMA: Channel %d: Memory error!\n", channel);
 379
 380         /*
 381          * Clear all interrupt flags
 382          */
 383         r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
 384                           r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 385                                            (channel << 5)) | R4030_TC_INTR
 386                           | R4030_MEM_INTR | R4030_ADDR_INTR);
 387
 388         /*
 389          * Enable the desired channel
 390          */
 391         r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
 392                           r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 393                                            (channel << 5)) |
 394                           R4030_CHNL_ENABLE);
 395 }
 396
 397 /*
 398  * Disable a DMA channel
 399  */
 400 void vdma_disable(int channel)
 401 {
 402         if (vdma_debug) {
 403                 int status =
 404                     r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 405                                      (channel << 5));
 406
 407                 printk("vdma_disable: channel %d\n", channel);
 408                 printk("VDMA: channel %d status: %04x (%s) mode: "
 409                        "%02x addr: %06x count: %06x\n",
 410                        channel, status,
 411                        ((status & 0x600) ? "ERROR" : "OK"),
 412                        (unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_MODE +
 413                                                    (channel << 5)),
 414                        (unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_ADDR +
 415                                                    (channel << 5)),
 416                        (unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_COUNT +
 417                                                    (channel << 5)));
 418         }
 419
 420         r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
 421                           r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 422                                            (channel << 5)) &
 423                           ~R4030_CHNL_ENABLE);
 424
 425         /*
 426          * After disabling a DMA channel a remote bus register should be
 427          * read to ensure that the current DMA acknowledge cycle is completed.
 428          */
 429         *((volatile unsigned int *) JAZZ_DUMMY_DEVICE);
 430 }
 431
 432 /*
 433  * Set DMA mode. This function accepts the mode values used
 434  * to set a PC-style DMA controller. For the SCSI and FDC
 435  * channels, we also set the default modes each time we're
 436  * called.
 437  * NOTE: The FAST and BURST dma modes are supported by the
 438  * R4030 Rev. 2 and PICA chipsets only. I leave them disabled
 439  * for now.
 440  */
 441 void vdma_set_mode(int channel, int mode)
 442 {
 443         if (vdma_debug)
 444                 printk("vdma_set_mode: channel %d, mode 0x%x\n", channel,
 445                        mode);
 446
 447         switch (channel) {
 448         case JAZZ_SCSI_DMA:     /* scsi */
 449                 r4030_write_reg32(JAZZ_R4030_CHNL_MODE + (channel << 5),
 450 /*                        R4030_MODE_FAST | */
 451 /*                        R4030_MODE_BURST | */
 452                                   R4030_MODE_INTR_EN |
 453                                   R4030_MODE_WIDTH_16 |
 454                                   R4030_MODE_ATIME_80);
 455                 break;
 456
 457         case JAZZ_FLOPPY_DMA:   /* floppy */
 458                 r4030_write_reg32(JAZZ_R4030_CHNL_MODE + (channel << 5),
 459 /*                        R4030_MODE_FAST | */
 460 /*                        R4030_MODE_BURST | */
 461                                   R4030_MODE_INTR_EN |
 462                                   R4030_MODE_WIDTH_8 |
 463                                   R4030_MODE_ATIME_120);
 464                 break;
 465
 466         case JAZZ_AUDIOL_DMA:
 467         case JAZZ_AUDIOR_DMA:
 468                 printk("VDMA: Audio DMA not supported yet.\n");
 469                 break;
 470
 471         default:
 472                 printk
 473                     ("VDMA: vdma_set_mode() called with unsupported channel %d!\n",
 474                      channel);
 475         }
 476
 477         switch (mode) {
 478         case DMA_MODE_READ:
 479                 r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
 480                                   r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 481                                                    (channel << 5)) &
 482                                   ~R4030_CHNL_WRITE);
 483                 break;
 484
 485         case DMA_MODE_WRITE:
 486                 r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
 487                                   r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 488                                                    (channel << 5)) |
 489                                   R4030_CHNL_WRITE);
 490                 break;
 491
 492         default:
 493                 printk
 494                     ("VDMA: vdma_set_mode() called with unknown dma mode 0x%x\n",
 495                      mode);
 496         }
 497 }
 498
 499 /*
 500  * Set Transfer Address
 501  */
 502 void vdma_set_addr(int channel, long addr)
 503 {
 504         if (vdma_debug)
 505                 printk("vdma_set_addr: channel %d, addr %lx\n", channel,
 506                        addr);
 507
 508         r4030_write_reg32(JAZZ_R4030_CHNL_ADDR + (channel << 5), addr);
 509 }
 510
 511 /*
 512  * Set Transfer Count
 513  */
 514 void vdma_set_count(int channel, int count)
 515 {
 516         if (vdma_debug)
 517                 printk("vdma_set_count: channel %d, count %08x\n", channel,
 518                        (unsigned) count);
 519
 520         r4030_write_reg32(JAZZ_R4030_CHNL_COUNT + (channel << 5), count);
 521 }
 522
 523 /*
 524  * Get Residual
 525  */
 526 int vdma_get_residue(int channel)
 527 {
 528         int residual;
 529
 530         residual = r4030_read_reg32(JAZZ_R4030_CHNL_COUNT + (channel << 5));
 531
 532         if (vdma_debug)
 533                 printk("vdma_get_residual: channel %d: residual=%d\n",
 534                        channel, residual);
 535
 536         return residual;
 537 }
 538
 539 /*
 540  * Get DMA channel enable register
 541  */
 542 int vdma_get_enable(int channel)
 543 {
 544         int enable;
 545
 546         enable = r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5));
 547
 548         if (vdma_debug)
 549                 printk("vdma_get_enable: channel %d: enable=%d\n", channel,
 550                        enable);
 551
 552         return enable;
 553 }