arch/mips/jazz/jazzdma.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Mips Jazz DMA controller support
   4  * Copyright (C) 1995, 1996 by Andreas Busse
   5  *
   6  * NOTE: Some of the argument checking could be removed when
   7  * things have settled down. Also, instead of returning 0xffffffff
   8  * on failure of vdma_alloc() one could leave page #0 unused
   9  * and return the more usual NULL pointer as logical address.
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13 #include <linux/export.h>
  14 #include <linux/errno.h>
  15 #include <linux/mm.h>
  16 #include <linux/bootmem.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/gfp.h>
  19 #include <asm/mipsregs.h>
  20 #include <asm/jazz.h>
  21 #include <asm/io.h>
  22 #include <linux/uaccess.h>
  23 #include <asm/dma.h>
  24 #include <asm/jazzdma.h>
  25 #include <asm/pgtable.h>
  26
  27 /*
  28  * Set this to one to enable additional vdma debug code.
  29  */
  30 #define CONF_DEBUG_VDMA 0
  31
  32 static VDMA_PGTBL_ENTRY *pgtbl;
  33
  34 static DEFINE_SPINLOCK(vdma_lock);
  35
  36 /*
  37  * Debug stuff
  38  */
  39 #define vdma_debug     ((CONF_DEBUG_VDMA) ? debuglvl : 0)
  40
  41 static int debuglvl = 3;
  42
  43 /*
  44  * Initialize the pagetable with a one-to-one mapping of
  45  * the first 16 Mbytes of main memory and declare all
  46  * entries to be unused. Using this method will at least
  47  * allow some early device driver operations to work.
  48  */
  49 static inline void vdma_pgtbl_init(void)
  50 {
  51         unsigned long paddr = 0;
  52         int i;
  53
  54         for (i = 0; i < VDMA_PGTBL_ENTRIES; i++) {
  55                 pgtbl[i].frame = paddr;
  56                 pgtbl[i].owner = VDMA_PAGE_EMPTY;
  57                 paddr += VDMA_PAGESIZE;
  58         }
  59 }
  60
  61 /*
  62  * Initialize the Jazz R4030 dma controller
  63  */
  64 static int __init vdma_init(void)
  65 {
  66         /*
  67          * Allocate 32k of memory for DMA page tables.  This needs to be page
  68          * aligned and should be uncached to avoid cache flushing after every
  69          * update.
  70          */
  71         pgtbl = (VDMA_PGTBL_ENTRY *)__get_free_pages(GFP_KERNEL | GFP_DMA,
  72                                                     get_order(VDMA_PGTBL_SIZE));
  73         BUG_ON(!pgtbl);
  74         dma_cache_wback_inv((unsigned long)pgtbl, VDMA_PGTBL_SIZE);
  75         pgtbl = (VDMA_PGTBL_ENTRY *)KSEG1ADDR(pgtbl);
  76
  77         /*
  78          * Clear the R4030 translation table
  79          */
  80         vdma_pgtbl_init();
  81
  82         r4030_write_reg32(JAZZ_R4030_TRSTBL_BASE, CPHYSADDR(pgtbl));
  83         r4030_write_reg32(JAZZ_R4030_TRSTBL_LIM, VDMA_PGTBL_SIZE);
  84         r4030_write_reg32(JAZZ_R4030_TRSTBL_INV, 0);
  85
  86         printk(KERN_INFO "VDMA: R4030 DMA pagetables initialized.\n");
  87         return 0;
  88 }
  89
  90 /*
  91  * Allocate DMA pagetables using a simple first-fit algorithm
  92  */
  93 unsigned long vdma_alloc(unsigned long paddr, unsigned long size)
  94 {
  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 = VDMA_PAGE(paddr + size) - VDMA_PAGE(paddr) + 1;
 117         first = 0;
 118         while (1) {
 119                 while (pgtbl[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 (pgtbl[last].owner == VDMA_PAGE_EMPTY
 128                        && last - first < pages)
 129                         last++;
 130
 131                 if (last - first == pages)
 132                         break;  /* found */
 133                 first = last + 1;
 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                 pgtbl[i].frame = frame;
 144                 pgtbl[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 ", pgtbl[i].frame);
 164                 printk("\nOWNER: ");
 165                 for (i = first; i < last; i++)
 166                         printk("%08x ", pgtbl[i].owner);
 167                 printk("\n");
 168         }
 169
 170         spin_unlock_irqrestore(&vdma_lock, flags);
 171
 172         return laddr;
 173 }
 174
 175 EXPORT_SYMBOL(vdma_alloc);
 176
 177 /*
 178  * Free previously allocated dma translation pages
 179  * Note that this does NOT change the translation table,
 180  * it just marks the free'd pages as unused!
 181  */
 182 int vdma_free(unsigned long laddr)
 183 {
 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 (i < VDMA_PGTBL_ENTRIES && pgtbl[i].owner == laddr) {
 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         int first, pages;
 216
 217         if (laddr > 0xffffff) {
 218                 if (vdma_debug)
 219                         printk
 220                             ("vdma_map: Invalid logical address: %08lx\n",
 221                              laddr);
 222                 return -EINVAL; /* invalid logical address */
 223         }
 224         if (paddr > 0x1fffffff) {
 225                 if (vdma_debug)
 226                         printk
 227                             ("vdma_map: Invalid physical address: %08lx\n",
 228                              paddr);
 229                 return -EINVAL; /* invalid physical address */
 230         }
 231
 232         pages = (((paddr & (VDMA_PAGESIZE - 1)) + size) >> 12) + 1;
 233         first = laddr >> 12;
 234         if (vdma_debug)
 235                 printk("vdma_remap: first=%x, pages=%x\n", first, pages);
 236         if (first + pages > VDMA_PGTBL_ENTRIES) {
 237                 if (vdma_debug)
 238                         printk("vdma_alloc: Invalid size: %08lx\n", size);
 239                 return -EINVAL;
 240         }
 241
 242         paddr &= ~(VDMA_PAGESIZE - 1);
 243         while (pages > 0 && first < VDMA_PGTBL_ENTRIES) {
 244                 if (pgtbl[first].owner != laddr) {
 245                         if (vdma_debug)
 246                                 printk("Trying to remap other's pages.\n");
 247                         return -EPERM;  /* not owner */
 248                 }
 249                 pgtbl[first].frame = paddr;
 250                 paddr += VDMA_PAGESIZE;
 251                 first++;
 252                 pages--;
 253         }
 254
 255         /*
 256          * Update translation table
 257          */
 258         r4030_write_reg32(JAZZ_R4030_TRSTBL_INV, 0);
 259
 260         if (vdma_debug > 2) {
 261                 int i;
 262                 pages = (((paddr & (VDMA_PAGESIZE - 1)) + size) >> 12) + 1;
 263                 first = laddr >> 12;
 264                 printk("LADDR: ");
 265                 for (i = first; i < first + pages; i++)
 266                         printk("%08x ", i << 12);
 267                 printk("\nPADDR: ");
 268                 for (i = first; i < first + pages; i++)
 269                         printk("%08x ", pgtbl[i].frame);
 270                 printk("\nOWNER: ");
 271                 for (i = first; i < first + pages; i++)
 272                         printk("%08x ", pgtbl[i].owner);
 273                 printk("\n");
 274         }
 275
 276         return 0;
 277 }
 278
 279 /*
 280  * Translate a physical address to a logical address.
 281  * This will return the logical address of the first
 282  * match.
 283  */
 284 unsigned long vdma_phys2log(unsigned long paddr)
 285 {
 286         int i;
 287         int frame;
 288
 289         frame = paddr & ~(VDMA_PAGESIZE - 1);
 290
 291         for (i = 0; i < VDMA_PGTBL_ENTRIES; i++) {
 292                 if (pgtbl[i].frame == frame)
 293                         break;
 294         }
 295
 296         if (i == VDMA_PGTBL_ENTRIES)
 297                 return ~0UL;
 298
 299         return (i << 12) + (paddr & (VDMA_PAGESIZE - 1));
 300 }
 301
 302 EXPORT_SYMBOL(vdma_phys2log);
 303
 304 /*
 305  * Translate a logical DMA address to a physical address
 306  */
 307 unsigned long vdma_log2phys(unsigned long laddr)
 308 {
 309         return pgtbl[laddr >> 12].frame + (laddr & (VDMA_PAGESIZE - 1));
 310 }
 311
 312 EXPORT_SYMBOL(vdma_log2phys);
 313
 314 /*
 315  * Print DMA statistics
 316  */
 317 void vdma_stats(void)
 318 {
 319         int i;
 320
 321         printk("vdma_stats: CONFIG: %08x\n",
 322                r4030_read_reg32(JAZZ_R4030_CONFIG));
 323         printk("R4030 translation table base: %08x\n",
 324                r4030_read_reg32(JAZZ_R4030_TRSTBL_BASE));
 325         printk("R4030 translation table limit: %08x\n",
 326                r4030_read_reg32(JAZZ_R4030_TRSTBL_LIM));
 327         printk("vdma_stats: INV_ADDR: %08x\n",
 328                r4030_read_reg32(JAZZ_R4030_INV_ADDR));
 329         printk("vdma_stats: R_FAIL_ADDR: %08x\n",
 330                r4030_read_reg32(JAZZ_R4030_R_FAIL_ADDR));
 331         printk("vdma_stats: M_FAIL_ADDR: %08x\n",
 332                r4030_read_reg32(JAZZ_R4030_M_FAIL_ADDR));
 333         printk("vdma_stats: IRQ_SOURCE: %08x\n",
 334                r4030_read_reg32(JAZZ_R4030_IRQ_SOURCE));
 335         printk("vdma_stats: I386_ERROR: %08x\n",
 336                r4030_read_reg32(JAZZ_R4030_I386_ERROR));
 337         printk("vdma_chnl_modes:   ");
 338         for (i = 0; i < 8; i++)
 339                 printk("%04x ",
 340                        (unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_MODE +
 341                                                    (i << 5)));
 342         printk("\n");
 343         printk("vdma_chnl_enables: ");
 344         for (i = 0; i < 8; i++)
 345                 printk("%04x ",
 346                        (unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 347                                                    (i << 5)));
 348         printk("\n");
 349 }
 350
 351 /*
 352  * DMA transfer functions
 353  */
 354
 355 /*
 356  * Enable a DMA channel. Also clear any error conditions.
 357  */
 358 void vdma_enable(int channel)
 359 {
 360         int status;
 361
 362         if (vdma_debug)
 363                 printk("vdma_enable: channel %d\n", channel);
 364
 365         /*
 366          * Check error conditions first
 367          */
 368         status = r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5));
 369         if (status & 0x400)
 370                 printk("VDMA: Channel %d: Address error!\n", channel);
 371         if (status & 0x200)
 372                 printk("VDMA: Channel %d: Memory error!\n", channel);
 373
 374         /*
 375          * Clear all interrupt flags
 376          */
 377         r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
 378                           r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 379                                            (channel << 5)) | R4030_TC_INTR
 380                           | R4030_MEM_INTR | R4030_ADDR_INTR);
 381
 382         /*
 383          * Enable the desired channel
 384          */
 385         r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
 386                           r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 387                                            (channel << 5)) |
 388                           R4030_CHNL_ENABLE);
 389 }
 390
 391 EXPORT_SYMBOL(vdma_enable);
 392
 393 /*
 394  * Disable a DMA channel
 395  */
 396 void vdma_disable(int channel)
 397 {
 398         if (vdma_debug) {
 399                 int status =
 400                     r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 401                                      (channel << 5));
 402
 403                 printk("vdma_disable: channel %d\n", channel);
 404                 printk("VDMA: channel %d status: %04x (%s) mode: "
 405                        "%02x addr: %06x count: %06x\n",
 406                        channel, status,
 407                        ((status & 0x600) ? "ERROR" : "OK"),
 408                        (unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_MODE +
 409                                                    (channel << 5)),
 410                        (unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_ADDR +
 411                                                    (channel << 5)),
 412                        (unsigned) r4030_read_reg32(JAZZ_R4030_CHNL_COUNT +
 413                                                    (channel << 5)));
 414         }
 415
 416         r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
 417                           r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 418                                            (channel << 5)) &
 419                           ~R4030_CHNL_ENABLE);
 420
 421         /*
 422          * After disabling a DMA channel a remote bus register should be
 423          * read to ensure that the current DMA acknowledge cycle is completed.
 424          */
 425         *((volatile unsigned int *) JAZZ_DUMMY_DEVICE);
 426 }
 427
 428 EXPORT_SYMBOL(vdma_disable);
 429
 430 /*
 431  * Set DMA mode. This function accepts the mode values used
 432  * to set a PC-style DMA controller. For the SCSI and FDC
 433  * channels, we also set the default modes each time we're
 434  * called.
 435  * NOTE: The FAST and BURST dma modes are supported by the
 436  * R4030 Rev. 2 and PICA chipsets only. I leave them disabled
 437  * for now.
 438  */
 439 void vdma_set_mode(int channel, int mode)
 440 {
 441         if (vdma_debug)
 442                 printk("vdma_set_mode: channel %d, mode 0x%x\n", channel,
 443                        mode);
 444
 445         switch (channel) {
 446         case JAZZ_SCSI_DMA:     /* scsi */
 447                 r4030_write_reg32(JAZZ_R4030_CHNL_MODE + (channel << 5),
 448 /*                        R4030_MODE_FAST | */
 449 /*                        R4030_MODE_BURST | */
 450                                   R4030_MODE_INTR_EN |
 451                                   R4030_MODE_WIDTH_16 |
 452                                   R4030_MODE_ATIME_80);
 453                 break;
 454
 455         case JAZZ_FLOPPY_DMA:   /* floppy */
 456                 r4030_write_reg32(JAZZ_R4030_CHNL_MODE + (channel << 5),
 457 /*                        R4030_MODE_FAST | */
 458 /*                        R4030_MODE_BURST | */
 459                                   R4030_MODE_INTR_EN |
 460                                   R4030_MODE_WIDTH_8 |
 461                                   R4030_MODE_ATIME_120);
 462                 break;
 463
 464         case JAZZ_AUDIOL_DMA:
 465         case JAZZ_AUDIOR_DMA:
 466                 printk("VDMA: Audio DMA not supported yet.\n");
 467                 break;
 468
 469         default:
 470                 printk
 471                     ("VDMA: vdma_set_mode() called with unsupported channel %d!\n",
 472                      channel);
 473         }
 474
 475         switch (mode) {
 476         case DMA_MODE_READ:
 477                 r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
 478                                   r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 479                                                    (channel << 5)) &
 480                                   ~R4030_CHNL_WRITE);
 481                 break;
 482
 483         case DMA_MODE_WRITE:
 484                 r4030_write_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5),
 485                                   r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE +
 486                                                    (channel << 5)) |
 487                                   R4030_CHNL_WRITE);
 488                 break;
 489
 490         default:
 491                 printk
 492                     ("VDMA: vdma_set_mode() called with unknown dma mode 0x%x\n",
 493                      mode);
 494         }
 495 }
 496
 497 EXPORT_SYMBOL(vdma_set_mode);
 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 EXPORT_SYMBOL(vdma_set_addr);
 512
 513 /*
 514  * Set Transfer Count
 515  */
 516 void vdma_set_count(int channel, int count)
 517 {
 518         if (vdma_debug)
 519                 printk("vdma_set_count: channel %d, count %08x\n", channel,
 520                        (unsigned) count);
 521
 522         r4030_write_reg32(JAZZ_R4030_CHNL_COUNT + (channel << 5), count);
 523 }
 524
 525 EXPORT_SYMBOL(vdma_set_count);
 526
 527 /*
 528  * Get Residual
 529  */
 530 int vdma_get_residue(int channel)
 531 {
 532         int residual;
 533
 534         residual = r4030_read_reg32(JAZZ_R4030_CHNL_COUNT + (channel << 5));
 535
 536         if (vdma_debug)
 537                 printk("vdma_get_residual: channel %d: residual=%d\n",
 538                        channel, residual);
 539
 540         return residual;
 541 }
 542
 543 /*
 544  * Get DMA channel enable register
 545  */
 546 int vdma_get_enable(int channel)
 547 {
 548         int enable;
 549
 550         enable = r4030_read_reg32(JAZZ_R4030_CHNL_ENABLE + (channel << 5));
 551
 552         if (vdma_debug)
 553                 printk("vdma_get_enable: channel %d: enable=%d\n", channel,
 554                        enable);
 555
 556         return enable;
 557 }
 558
 559 arch_initcall(vdma_init);