drivers/scsi/mac_scsi.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Generic Macintosh NCR5380 driver
   4  *
   5  * Copyright 1998, Michael Schmitz <[email protected]>
   6  *
   7  * Copyright 2019 Finn Thain
   8  *
   9  * derived in part from:
  10  */
  11 /*
  12  * Generic Generic NCR5380 driver
  13  *
  14  * Copyright 1995, Russell King
  15  */
  16
  17 #include <linux/delay.h>
  18 #include <linux/types.h>
  19 #include <linux/module.h>
  20 #include <linux/ioport.h>
  21 #include <linux/init.h>
  22 #include <linux/blkdev.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/platform_device.h>
  25
  26 #include <asm/hwtest.h>
  27 #include <asm/io.h>
  28 #include <asm/macintosh.h>
  29 #include <asm/macints.h>
  30 #include <asm/setup.h>
  31
  32 #include <scsi/scsi_host.h>
  33
  34 /* Definitions for the core NCR5380 driver. */
  35
  36 #define NCR5380_implementation_fields   int pdma_residual
  37
  38 #define NCR5380_read(reg)           in_8(hostdata->io + ((reg) << 4))
  39 #define NCR5380_write(reg, value)   out_8(hostdata->io + ((reg) << 4), value)
  40
  41 #define NCR5380_dma_xfer_len            macscsi_dma_xfer_len
  42 #define NCR5380_dma_recv_setup          macscsi_pread
  43 #define NCR5380_dma_send_setup          macscsi_pwrite
  44 #define NCR5380_dma_residual            macscsi_dma_residual
  45
  46 #define NCR5380_intr                    macscsi_intr
  47 #define NCR5380_queue_command           macscsi_queue_command
  48 #define NCR5380_abort                   macscsi_abort
  49 #define NCR5380_host_reset              macscsi_host_reset
  50 #define NCR5380_info                    macscsi_info
  51
  52 #include "NCR5380.h"
  53
  54 static int setup_can_queue = -1;
  55 module_param(setup_can_queue, int, 0);
  56 static int setup_cmd_per_lun = -1;
  57 module_param(setup_cmd_per_lun, int, 0);
  58 static int setup_sg_tablesize = -1;
  59 module_param(setup_sg_tablesize, int, 0);
  60 static int setup_use_pdma = 512;
  61 module_param(setup_use_pdma, int, 0);
  62 static int setup_hostid = -1;
  63 module_param(setup_hostid, int, 0);
  64 static int setup_toshiba_delay = -1;
  65 module_param(setup_toshiba_delay, int, 0);
  66
  67 #ifndef MODULE
  68 static int __init mac_scsi_setup(char *str)
  69 {
  70         int ints[8];
  71
  72         (void)get_options(str, ARRAY_SIZE(ints), ints);
  73
  74         if (ints[0] < 1) {
  75                 pr_err("Usage: mac5380=<can_queue>[,<cmd_per_lun>[,<sg_tablesize>[,<hostid>[,<use_tags>[,<use_pdma>[,<toshiba_delay>]]]]]]\n");
  76                 return 0;
  77         }
  78         if (ints[0] >= 1)
  79                 setup_can_queue = ints[1];
  80         if (ints[0] >= 2)
  81                 setup_cmd_per_lun = ints[2];
  82         if (ints[0] >= 3)
  83                 setup_sg_tablesize = ints[3];
  84         if (ints[0] >= 4)
  85                 setup_hostid = ints[4];
  86         /* ints[5] (use_tagged_queuing) is ignored */
  87         if (ints[0] >= 6)
  88                 setup_use_pdma = ints[6];
  89         if (ints[0] >= 7)
  90                 setup_toshiba_delay = ints[7];
  91         return 1;
  92 }
  93
  94 __setup("mac5380=", mac_scsi_setup);
  95 #endif /* !MODULE */
  96
  97 /*
  98  * According to "Inside Macintosh: Devices", Mac OS requires disk drivers to
  99  * specify the number of bytes between the delays expected from a SCSI target.
 100  * This allows the operating system to "prevent bus errors when a target fails
 101  * to deliver the next byte within the processor bus error timeout period."
 102  * Linux SCSI drivers lack knowledge of the timing behaviour of SCSI targets
 103  * so bus errors are unavoidable.
 104  *
 105  * If a MOVE.B instruction faults during a receive operation, we assume the
 106  * target sent nothing and try again. That assumption probably depends on
 107  * target firmware but it seems to hold up okay. If a fault happens during a
 108  * send operation, the target may or may not have seen /ACK and got the byte.
 109  * It's uncertain so the whole SCSI command gets retried.
 110  *
 111  * The NOP is needed for synchronization because the fault address in the
 112  * exception stack frame may or may not be the instruction that actually
 113  * caused the bus error. Post-increment addressing can't be used.
 114  */
 115
 116 #define MOVE_BYTE(operands) \
 117         asm volatile ( \
 118                 "1:     moveb " operands "     \n" \
 119                 "11:    nop                    \n" \
 120                 "       addq #1,%0             \n" \
 121                 "       subq #1,%1             \n" \
 122                 "40:                           \n" \
 123                 "                              \n" \
 124                 ".section .fixup,\"ax\"        \n" \
 125                 ".even                         \n" \
 126                 "90:    movel #1, %2           \n" \
 127                 "       jra 40b                \n" \
 128                 ".previous                     \n" \
 129                 "                              \n" \
 130                 ".section __ex_table,\"a\"     \n" \
 131                 ".align  4                     \n" \
 132                 ".long   1b,90b                \n" \
 133                 ".long  11b,90b                \n" \
 134                 ".previous                     \n" \
 135                 : "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
 136
 137 /*
 138  * If a MOVE.W (or MOVE.L) instruction faults, it cannot be retried because
 139  * the residual byte count would be uncertain. In that situation the MOVE_WORD
 140  * macro clears n in the fixup section to abort the transfer.
 141  */
 142
 143 #define MOVE_WORD(operands) \
 144         asm volatile ( \
 145                 "1:     movew " operands "     \n" \
 146                 "11:    nop                    \n" \
 147                 "       subq #2,%1             \n" \
 148                 "40:                           \n" \
 149                 "                              \n" \
 150                 ".section .fixup,\"ax\"        \n" \
 151                 ".even                         \n" \
 152                 "90:    movel #0, %1           \n" \
 153                 "       movel #2, %2           \n" \
 154                 "       jra 40b                \n" \
 155                 ".previous                     \n" \
 156                 "                              \n" \
 157                 ".section __ex_table,\"a\"     \n" \
 158                 ".align  4                     \n" \
 159                 ".long   1b,90b                \n" \
 160                 ".long  11b,90b                \n" \
 161                 ".previous                     \n" \
 162                 : "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
 163
 164 #define MOVE_16_WORDS(operands) \
 165         asm volatile ( \
 166                 "1:     movew " operands "     \n" \
 167                 "2:     movew " operands "     \n" \
 168                 "3:     movew " operands "     \n" \
 169                 "4:     movew " operands "     \n" \
 170                 "5:     movew " operands "     \n" \
 171                 "6:     movew " operands "     \n" \
 172                 "7:     movew " operands "     \n" \
 173                 "8:     movew " operands "     \n" \
 174                 "9:     movew " operands "     \n" \
 175                 "10:    movew " operands "     \n" \
 176                 "11:    movew " operands "     \n" \
 177                 "12:    movew " operands "     \n" \
 178                 "13:    movew " operands "     \n" \
 179                 "14:    movew " operands "     \n" \
 180                 "15:    movew " operands "     \n" \
 181                 "16:    movew " operands "     \n" \
 182                 "17:    nop                    \n" \
 183                 "       subl  #32,%1           \n" \
 184                 "40:                           \n" \
 185                 "                              \n" \
 186                 ".section .fixup,\"ax\"        \n" \
 187                 ".even                         \n" \
 188                 "90:    movel #0, %1           \n" \
 189                 "       movel #2, %2           \n" \
 190                 "       jra 40b                \n" \
 191                 ".previous                     \n" \
 192                 "                              \n" \
 193                 ".section __ex_table,\"a\"     \n" \
 194                 ".align  4                     \n" \
 195                 ".long   1b,90b                \n" \
 196                 ".long   2b,90b                \n" \
 197                 ".long   3b,90b                \n" \
 198                 ".long   4b,90b                \n" \
 199                 ".long   5b,90b                \n" \
 200                 ".long   6b,90b                \n" \
 201                 ".long   7b,90b                \n" \
 202                 ".long   8b,90b                \n" \
 203                 ".long   9b,90b                \n" \
 204                 ".long  10b,90b                \n" \
 205                 ".long  11b,90b                \n" \
 206                 ".long  12b,90b                \n" \
 207                 ".long  13b,90b                \n" \
 208                 ".long  14b,90b                \n" \
 209                 ".long  15b,90b                \n" \
 210                 ".long  16b,90b                \n" \
 211                 ".long  17b,90b                \n" \
 212                 ".previous                     \n" \
 213                 : "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
 214
 215 static inline int mac_pdma_recv(void __iomem *io, unsigned char *start, int n)
 216 {
 217         unsigned char *addr = start;
 218         int result = 0;
 219
 220         if (n >= 1) {
 221                 MOVE_BYTE("%3@,%0@");
 222                 if (result)
 223                         goto out;
 224         }
 225         if (n >= 1 && ((unsigned long)addr & 1)) {
 226                 MOVE_BYTE("%3@,%0@");
 227                 if (result)
 228                         goto out;
 229         }
 230         while (n >= 32)
 231                 MOVE_16_WORDS("%3@,%0@+");
 232         while (n >= 2)
 233                 MOVE_WORD("%3@,%0@+");
 234         if (result)
 235                 return start - addr; /* Negated to indicate uncertain length */
 236         if (n == 1)
 237                 MOVE_BYTE("%3@,%0@");
 238 out:
 239         return addr - start;
 240 }
 241
 242 static inline int mac_pdma_send(unsigned char *start, void __iomem *io, int n)
 243 {
 244         unsigned char *addr = start;
 245         int result = 0;
 246
 247         if (n >= 1) {
 248                 MOVE_BYTE("%0@,%3@");
 249                 if (result)
 250                         return -1;
 251         }
 252         if (n >= 1 && ((unsigned long)addr & 1)) {
 253                 MOVE_BYTE("%0@,%3@");
 254                 if (result)
 255                         return -2;
 256         }
 257         while (n >= 32)
 258                 MOVE_16_WORDS("%0@+,%3@");
 259         while (n >= 2)
 260                 MOVE_WORD("%0@+,%3@");
 261         if (result)
 262                 return start - addr - 1; /* Negated to indicate uncertain length */
 263         if (n == 1)
 264                 MOVE_BYTE("%0@,%3@");
 265         return addr - start;
 266 }
 267
 268 /* The "SCSI DMA" chip on the IIfx implements this register. */
 269 #define CTRL_REG                0x8
 270 #define CTRL_INTERRUPTS_ENABLE  BIT(1)
 271 #define CTRL_HANDSHAKE_MODE     BIT(3)
 272
 273 static inline void write_ctrl_reg(struct NCR5380_hostdata *hostdata, u32 value)
 274 {
 275         out_be32(hostdata->io + (CTRL_REG << 4), value);
 276 }
 277
 278 static inline int macscsi_wait_for_drq(struct NCR5380_hostdata *hostdata)
 279 {
 280         unsigned int n = 1; /* effectively multiplies NCR5380_REG_POLL_TIME */
 281         unsigned char basr;
 282
 283 again:
 284         basr = NCR5380_read(BUS_AND_STATUS_REG);
 285
 286         if (!(basr & BASR_PHASE_MATCH))
 287                 return 1;
 288
 289         if (basr & BASR_IRQ)
 290                 return -1;
 291
 292         if (basr & BASR_DRQ)
 293                 return 0;
 294
 295         if (n-- == 0) {
 296                 NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
 297                 dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
 298                          "%s: DRQ timeout\n", __func__);
 299                 return -1;
 300         }
 301
 302         NCR5380_poll_politely2(hostdata,
 303                                BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
 304                                BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, 0);
 305         goto again;
 306 }
 307
 308 static inline int macscsi_pread(struct NCR5380_hostdata *hostdata,
 309                                 unsigned char *dst, int len)
 310 {
 311         u8 __iomem *s = hostdata->pdma_io + (INPUT_DATA_REG << 4);
 312         unsigned char *d = dst;
 313
 314         hostdata->pdma_residual = len;
 315
 316         while (macscsi_wait_for_drq(hostdata) == 0) {
 317                 int bytes, chunk_bytes;
 318
 319                 if (macintosh_config->ident == MAC_MODEL_IIFX)
 320                         write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE |
 321                                                  CTRL_INTERRUPTS_ENABLE);
 322
 323                 chunk_bytes = min(hostdata->pdma_residual, 512);
 324                 bytes = mac_pdma_recv(s, d, chunk_bytes);
 325
 326                 if (macintosh_config->ident == MAC_MODEL_IIFX)
 327                         write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
 328
 329                 if (bytes > 0) {
 330                         d += bytes;
 331                         hostdata->pdma_residual -= bytes;
 332                 }
 333
 334                 if (hostdata->pdma_residual == 0)
 335                         break;
 336
 337                 if (bytes > 0)
 338                         continue;
 339
 340                 NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
 341                 dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
 342                          "%s: bus error [%d/%d] (%d/%d)\n",
 343                          __func__, d - dst, len, bytes, chunk_bytes);
 344
 345                 if (bytes == 0)
 346                         continue;
 347
 348                 if (macscsi_wait_for_drq(hostdata) <= 0)
 349                         set_host_byte(hostdata->connected, DID_ERROR);
 350                 break;
 351         }
 352
 353         return 0;
 354 }
 355
 356 static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata,
 357                                  unsigned char *src, int len)
 358 {
 359         unsigned char *s = src;
 360         u8 __iomem *d = hostdata->pdma_io + (OUTPUT_DATA_REG << 4);
 361
 362         hostdata->pdma_residual = len;
 363
 364         while (macscsi_wait_for_drq(hostdata) == 0) {
 365                 int bytes, chunk_bytes;
 366
 367                 if (macintosh_config->ident == MAC_MODEL_IIFX)
 368                         write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE |
 369                                                  CTRL_INTERRUPTS_ENABLE);
 370
 371                 chunk_bytes = min(hostdata->pdma_residual, 512);
 372                 bytes = mac_pdma_send(s, d, chunk_bytes);
 373
 374                 if (macintosh_config->ident == MAC_MODEL_IIFX)
 375                         write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
 376
 377                 if (bytes > 0) {
 378                         s += bytes;
 379                         hostdata->pdma_residual -= bytes;
 380                 }
 381
 382                 if (hostdata->pdma_residual == 0)
 383                         break;
 384
 385                 if (bytes > 0)
 386                         continue;
 387
 388                 NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
 389                 dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
 390                          "%s: bus error [%d/%d] (%d/%d)\n",
 391                          __func__, s - src, len, bytes, chunk_bytes);
 392
 393                 if (bytes == 0)
 394                         continue;
 395
 396                 if (macscsi_wait_for_drq(hostdata) <= 0)
 397                         set_host_byte(hostdata->connected, DID_ERROR);
 398                 break;
 399         }
 400
 401         return 0;
 402 }
 403
 404 static int macscsi_dma_xfer_len(struct NCR5380_hostdata *hostdata,
 405                                 struct scsi_cmnd *cmd)
 406 {
 407         int resid = NCR5380_to_ncmd(cmd)->this_residual;
 408
 409         if (hostdata->flags & FLAG_NO_PSEUDO_DMA || resid < setup_use_pdma)
 410                 return 0;
 411
 412         return resid;
 413 }
 414
 415 static int macscsi_dma_residual(struct NCR5380_hostdata *hostdata)
 416 {
 417         return hostdata->pdma_residual;
 418 }
 419
 420 #include "NCR5380.c"
 421
 422 #define DRV_MODULE_NAME         "mac_scsi"
 423 #define PFX                     DRV_MODULE_NAME ": "
 424
 425 static struct scsi_host_template mac_scsi_template = {
 426         .module                 = THIS_MODULE,
 427         .proc_name              = DRV_MODULE_NAME,
 428         .name                   = "Macintosh NCR5380 SCSI",
 429         .info                   = macscsi_info,
 430         .queuecommand           = macscsi_queue_command,
 431         .eh_abort_handler       = macscsi_abort,
 432         .eh_host_reset_handler  = macscsi_host_reset,
 433         .can_queue              = 16,
 434         .this_id                = 7,
 435         .sg_tablesize           = SG_ALL,
 436         .cmd_per_lun            = 2,
 437         .dma_boundary           = PAGE_SIZE - 1,
 438         .cmd_size               = sizeof(struct NCR5380_cmd),
 439         .max_sectors            = 128,
 440 };
 441
 442 static int __init mac_scsi_probe(struct platform_device *pdev)
 443 {
 444         struct Scsi_Host *instance;
 445         struct NCR5380_hostdata *hostdata;
 446         int error;
 447         int host_flags = 0;
 448         struct resource *irq, *pio_mem, *pdma_mem = NULL;
 449
 450         pio_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 451         if (!pio_mem)
 452                 return -ENODEV;
 453
 454         pdma_mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 455
 456         irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 457
 458         if (!hwreg_present((unsigned char *)pio_mem->start +
 459                            (STATUS_REG << 4))) {
 460                 pr_info(PFX "no device detected at %pap\n", &pio_mem->start);
 461                 return -ENODEV;
 462         }
 463
 464         if (setup_can_queue > 0)
 465                 mac_scsi_template.can_queue = setup_can_queue;
 466         if (setup_cmd_per_lun > 0)
 467                 mac_scsi_template.cmd_per_lun = setup_cmd_per_lun;
 468         if (setup_sg_tablesize > 0)
 469                 mac_scsi_template.sg_tablesize = setup_sg_tablesize;
 470         if (setup_hostid >= 0)
 471                 mac_scsi_template.this_id = setup_hostid & 7;
 472
 473         if (macintosh_config->ident == MAC_MODEL_IIFX)
 474                 mac_scsi_template.sg_tablesize = 1;
 475
 476         instance = scsi_host_alloc(&mac_scsi_template,
 477                                    sizeof(struct NCR5380_hostdata));
 478         if (!instance)
 479                 return -ENOMEM;
 480
 481         if (irq)
 482                 instance->irq = irq->start;
 483         else
 484                 instance->irq = NO_IRQ;
 485
 486         hostdata = shost_priv(instance);
 487         hostdata->base = pio_mem->start;
 488         hostdata->io = (u8 __iomem *)pio_mem->start;
 489
 490         if (pdma_mem && setup_use_pdma)
 491                 hostdata->pdma_io = (u8 __iomem *)pdma_mem->start;
 492         else
 493                 host_flags |= FLAG_NO_PSEUDO_DMA;
 494
 495         host_flags |= setup_toshiba_delay > 0 ? FLAG_TOSHIBA_DELAY : 0;
 496
 497         if (instance->sg_tablesize > 1)
 498                 host_flags |= FLAG_DMA_FIXUP;
 499
 500         error = NCR5380_init(instance, host_flags | FLAG_LATE_DMA_SETUP);
 501         if (error)
 502                 goto fail_init;
 503
 504         if (instance->irq != NO_IRQ) {
 505                 error = request_irq(instance->irq, macscsi_intr, IRQF_SHARED,
 506                                     "NCR5380", instance);
 507                 if (error)
 508                         goto fail_irq;
 509         }
 510
 511         NCR5380_maybe_reset_bus(instance);
 512
 513         error = scsi_add_host(instance, NULL);
 514         if (error)
 515                 goto fail_host;
 516
 517         platform_set_drvdata(pdev, instance);
 518
 519         scsi_scan_host(instance);
 520         return 0;
 521
 522 fail_host:
 523         if (instance->irq != NO_IRQ)
 524                 free_irq(instance->irq, instance);
 525 fail_irq:
 526         NCR5380_exit(instance);
 527 fail_init:
 528         scsi_host_put(instance);
 529         return error;
 530 }
 531
 532 static void __exit mac_scsi_remove(struct platform_device *pdev)
 533 {
 534         struct Scsi_Host *instance = platform_get_drvdata(pdev);
 535
 536         scsi_remove_host(instance);
 537         if (instance->irq != NO_IRQ)
 538                 free_irq(instance->irq, instance);
 539         NCR5380_exit(instance);
 540         scsi_host_put(instance);
 541 }
 542
 543 /*
 544  * mac_scsi_remove() lives in .exit.text. For drivers registered via
 545  * module_platform_driver_probe() this is ok because they cannot get unbound at
 546  * runtime. So mark the driver struct with __refdata to prevent modpost
 547  * triggering a section mismatch warning.
 548  */
 549 static struct platform_driver mac_scsi_driver __refdata = {
 550         .remove = __exit_p(mac_scsi_remove),
 551         .driver = {
 552                 .name   = DRV_MODULE_NAME,
 553         },
 554 };
 555
 556 module_platform_driver_probe(mac_scsi_driver, mac_scsi_probe);
 557
 558 MODULE_ALIAS("platform:" DRV_MODULE_NAME);
 559 MODULE_DESCRIPTION("Macintosh NCR5380 SCSI driver");
 560 MODULE_LICENSE("GPL");