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