| 1 | /* |
| 2 | * NCR 5380 generic driver routines. These should make it *trivial* |
| 3 | * to implement 5380 SCSI drivers under Linux with a non-trantor |
| 4 | * architecture. |
| 5 | * |
| 6 | * Note that these routines also work with NR53c400 family chips. |
| 7 | * |
| 8 | * Copyright 1993, Drew Eckhardt |
| 9 | * Visionary Computing |
| 10 | * (Unix and Linux consulting and custom programming) |
| 11 | * drew@colorado.edu |
| 12 | * +1 (303) 666-5836 |
| 13 | * |
| 14 | * DISTRIBUTION RELEASE 6. |
| 15 | * |
| 16 | * For more information, please consult |
| 17 | * |
| 18 | * NCR 5380 Family |
| 19 | * SCSI Protocol Controller |
| 20 | * Databook |
| 21 | * |
| 22 | * NCR Microelectronics |
| 23 | * 1635 Aeroplaza Drive |
| 24 | * Colorado Springs, CO 80916 |
| 25 | * 1+ (719) 578-3400 |
| 26 | * 1+ (800) 334-5454 |
| 27 | */ |
| 28 | |
| 29 | /* |
| 30 | * ++roman: To port the 5380 driver to the Atari, I had to do some changes in |
| 31 | * this file, too: |
| 32 | * |
| 33 | * - Some of the debug statements were incorrect (undefined variables and the |
| 34 | * like). I fixed that. |
| 35 | * |
| 36 | * - In information_transfer(), I think a #ifdef was wrong. Looking at the |
| 37 | * possible DMA transfer size should also happen for REAL_DMA. I added this |
| 38 | * in the #if statement. |
| 39 | * |
| 40 | * - When using real DMA, information_transfer() should return in a DATAOUT |
| 41 | * phase after starting the DMA. It has nothing more to do. |
| 42 | * |
| 43 | * - The interrupt service routine should run main after end of DMA, too (not |
| 44 | * only after RESELECTION interrupts). Additionally, it should _not_ test |
| 45 | * for more interrupts after running main, since a DMA process may have |
| 46 | * been started and interrupts are turned on now. The new int could happen |
| 47 | * inside the execution of NCR5380_intr(), leading to recursive |
| 48 | * calls. |
| 49 | * |
| 50 | * - I've added a function merge_contiguous_buffers() that tries to |
| 51 | * merge scatter-gather buffers that are located at contiguous |
| 52 | * physical addresses and can be processed with the same DMA setup. |
| 53 | * Since most scatter-gather operations work on a page (4K) of |
| 54 | * 4 buffers (1K), in more than 90% of all cases three interrupts and |
| 55 | * DMA setup actions are saved. |
| 56 | * |
| 57 | * - I've deleted all the stuff for AUTOPROBE_IRQ, REAL_DMA_POLL, PSEUDO_DMA |
| 58 | * and USLEEP, because these were messing up readability and will never be |
| 59 | * needed for Atari SCSI. |
| 60 | * |
| 61 | * - I've revised the NCR5380_main() calling scheme (relax the 'main_running' |
| 62 | * stuff), and 'main' is executed in a bottom half if awoken by an |
| 63 | * interrupt. |
| 64 | * |
| 65 | * - The code was quite cluttered up by "#if (NDEBUG & NDEBUG_*) printk..." |
| 66 | * constructs. In my eyes, this made the source rather unreadable, so I |
| 67 | * finally replaced that by the *_PRINTK() macros. |
| 68 | * |
| 69 | */ |
| 70 | |
| 71 | /* |
| 72 | * Further development / testing that should be done : |
| 73 | * 1. Test linked command handling code after Eric is ready with |
| 74 | * the high level code. |
| 75 | */ |
| 76 | #include <scsi/scsi_dbg.h> |
| 77 | #include <scsi/scsi_transport_spi.h> |
| 78 | |
| 79 | #if (NDEBUG & NDEBUG_LISTS) |
| 80 | #define LIST(x,y) \ |
| 81 | { printk("LINE:%d Adding %p to %p\n", __LINE__, (void*)(x), (void*)(y)); \ |
| 82 | if ((x)==(y)) udelay(5); } |
| 83 | #define REMOVE(w,x,y,z) \ |
| 84 | { printk("LINE:%d Removing: %p->%p %p->%p \n", __LINE__, \ |
| 85 | (void*)(w), (void*)(x), (void*)(y), (void*)(z)); \ |
| 86 | if ((x)==(y)) udelay(5); } |
| 87 | #else |
| 88 | #define LIST(x,y) |
| 89 | #define REMOVE(w,x,y,z) |
| 90 | #endif |
| 91 | |
| 92 | #ifndef notyet |
| 93 | #undef LINKED |
| 94 | #endif |
| 95 | |
| 96 | /* |
| 97 | * Design |
| 98 | * Issues : |
| 99 | * |
| 100 | * The other Linux SCSI drivers were written when Linux was Intel PC-only, |
| 101 | * and specifically for each board rather than each chip. This makes their |
| 102 | * adaptation to platforms like the Mac (Some of which use NCR5380's) |
| 103 | * more difficult than it has to be. |
| 104 | * |
| 105 | * Also, many of the SCSI drivers were written before the command queuing |
| 106 | * routines were implemented, meaning their implementations of queued |
| 107 | * commands were hacked on rather than designed in from the start. |
| 108 | * |
| 109 | * When I designed the Linux SCSI drivers I figured that |
| 110 | * while having two different SCSI boards in a system might be useful |
| 111 | * for debugging things, two of the same type wouldn't be used. |
| 112 | * Well, I was wrong and a number of users have mailed me about running |
| 113 | * multiple high-performance SCSI boards in a server. |
| 114 | * |
| 115 | * Finally, when I get questions from users, I have no idea what |
| 116 | * revision of my driver they are running. |
| 117 | * |
| 118 | * This driver attempts to address these problems : |
| 119 | * This is a generic 5380 driver. To use it on a different platform, |
| 120 | * one simply writes appropriate system specific macros (ie, data |
| 121 | * transfer - some PC's will use the I/O bus, 68K's must use |
| 122 | * memory mapped) and drops this file in their 'C' wrapper. |
| 123 | * |
| 124 | * As far as command queueing, two queues are maintained for |
| 125 | * each 5380 in the system - commands that haven't been issued yet, |
| 126 | * and commands that are currently executing. This means that an |
| 127 | * unlimited number of commands may be queued, letting |
| 128 | * more commands propagate from the higher driver levels giving higher |
| 129 | * throughput. Note that both I_T_L and I_T_L_Q nexuses are supported, |
| 130 | * allowing multiple commands to propagate all the way to a SCSI-II device |
| 131 | * while a command is already executing. |
| 132 | * |
| 133 | * To solve the multiple-boards-in-the-same-system problem, |
| 134 | * there is a separate instance structure for each instance |
| 135 | * of a 5380 in the system. So, multiple NCR5380 drivers will |
| 136 | * be able to coexist with appropriate changes to the high level |
| 137 | * SCSI code. |
| 138 | * |
| 139 | * A NCR5380_PUBLIC_REVISION macro is provided, with the release |
| 140 | * number (updated for each public release) printed by the |
| 141 | * NCR5380_print_options command, which should be called from the |
| 142 | * wrapper detect function, so that I know what release of the driver |
| 143 | * users are using. |
| 144 | * |
| 145 | * Issues specific to the NCR5380 : |
| 146 | * |
| 147 | * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead |
| 148 | * piece of hardware that requires you to sit in a loop polling for |
| 149 | * the REQ signal as long as you are connected. Some devices are |
| 150 | * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect |
| 151 | * while doing long seek operations. |
| 152 | * |
| 153 | * The workaround for this is to keep track of devices that have |
| 154 | * disconnected. If the device hasn't disconnected, for commands that |
| 155 | * should disconnect, we do something like |
| 156 | * |
| 157 | * while (!REQ is asserted) { sleep for N usecs; poll for M usecs } |
| 158 | * |
| 159 | * Some tweaking of N and M needs to be done. An algorithm based |
| 160 | * on "time to data" would give the best results as long as short time |
| 161 | * to datas (ie, on the same track) were considered, however these |
| 162 | * broken devices are the exception rather than the rule and I'd rather |
| 163 | * spend my time optimizing for the normal case. |
| 164 | * |
| 165 | * Architecture : |
| 166 | * |
| 167 | * At the heart of the design is a coroutine, NCR5380_main, |
| 168 | * which is started when not running by the interrupt handler, |
| 169 | * timer, and queue command function. It attempts to establish |
| 170 | * I_T_L or I_T_L_Q nexuses by removing the commands from the |
| 171 | * issue queue and calling NCR5380_select() if a nexus |
| 172 | * is not established. |
| 173 | * |
| 174 | * Once a nexus is established, the NCR5380_information_transfer() |
| 175 | * phase goes through the various phases as instructed by the target. |
| 176 | * if the target goes into MSG IN and sends a DISCONNECT message, |
| 177 | * the command structure is placed into the per instance disconnected |
| 178 | * queue, and NCR5380_main tries to find more work. If USLEEP |
| 179 | * was defined, and the target is idle for too long, the system |
| 180 | * will try to sleep. |
| 181 | * |
| 182 | * If a command has disconnected, eventually an interrupt will trigger, |
| 183 | * calling NCR5380_intr() which will in turn call NCR5380_reselect |
| 184 | * to reestablish a nexus. This will run main if necessary. |
| 185 | * |
| 186 | * On command termination, the done function will be called as |
| 187 | * appropriate. |
| 188 | * |
| 189 | * SCSI pointers are maintained in the SCp field of SCSI command |
| 190 | * structures, being initialized after the command is connected |
| 191 | * in NCR5380_select, and set as appropriate in NCR5380_information_transfer. |
| 192 | * Note that in violation of the standard, an implicit SAVE POINTERS operation |
| 193 | * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS. |
| 194 | */ |
| 195 | |
| 196 | /* |
| 197 | * Using this file : |
| 198 | * This file a skeleton Linux SCSI driver for the NCR 5380 series |
| 199 | * of chips. To use it, you write an architecture specific functions |
| 200 | * and macros and include this file in your driver. |
| 201 | * |
| 202 | * These macros control options : |
| 203 | * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically |
| 204 | * for commands that return with a CHECK CONDITION status. |
| 205 | * |
| 206 | * LINKED - if defined, linked commands are supported. |
| 207 | * |
| 208 | * REAL_DMA - if defined, REAL DMA is used during the data transfer phases. |
| 209 | * |
| 210 | * SUPPORT_TAGS - if defined, SCSI-2 tagged queuing is used where possible |
| 211 | * |
| 212 | * These macros MUST be defined : |
| 213 | * |
| 214 | * NCR5380_read(register) - read from the specified register |
| 215 | * |
| 216 | * NCR5380_write(register, value) - write to the specific register |
| 217 | * |
| 218 | * Either real DMA *or* pseudo DMA may be implemented |
| 219 | * REAL functions : |
| 220 | * NCR5380_REAL_DMA should be defined if real DMA is to be used. |
| 221 | * Note that the DMA setup functions should return the number of bytes |
| 222 | * that they were able to program the controller for. |
| 223 | * |
| 224 | * Also note that generic i386/PC versions of these macros are |
| 225 | * available as NCR5380_i386_dma_write_setup, |
| 226 | * NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual. |
| 227 | * |
| 228 | * NCR5380_dma_write_setup(instance, src, count) - initialize |
| 229 | * NCR5380_dma_read_setup(instance, dst, count) - initialize |
| 230 | * NCR5380_dma_residual(instance); - residual count |
| 231 | * |
| 232 | * PSEUDO functions : |
| 233 | * NCR5380_pwrite(instance, src, count) |
| 234 | * NCR5380_pread(instance, dst, count); |
| 235 | * |
| 236 | * If nothing specific to this implementation needs doing (ie, with external |
| 237 | * hardware), you must also define |
| 238 | * |
| 239 | * NCR5380_queue_command |
| 240 | * NCR5380_reset |
| 241 | * NCR5380_abort |
| 242 | * NCR5380_proc_info |
| 243 | * |
| 244 | * to be the global entry points into the specific driver, ie |
| 245 | * #define NCR5380_queue_command t128_queue_command. |
| 246 | * |
| 247 | * If this is not done, the routines will be defined as static functions |
| 248 | * with the NCR5380* names and the user must provide a globally |
| 249 | * accessible wrapper function. |
| 250 | * |
| 251 | * The generic driver is initialized by calling NCR5380_init(instance), |
| 252 | * after setting the appropriate host specific fields and ID. If the |
| 253 | * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance, |
| 254 | * possible) function may be used. Before the specific driver initialization |
| 255 | * code finishes, NCR5380_print_options should be called. |
| 256 | */ |
| 257 | |
| 258 | static struct Scsi_Host *first_instance = NULL; |
| 259 | static struct scsi_host_template *the_template = NULL; |
| 260 | |
| 261 | /* Macros ease life... :-) */ |
| 262 | #define SETUP_HOSTDATA(in) \ |
| 263 | struct NCR5380_hostdata *hostdata = \ |
| 264 | (struct NCR5380_hostdata *)(in)->hostdata |
| 265 | #define HOSTDATA(in) ((struct NCR5380_hostdata *)(in)->hostdata) |
| 266 | |
| 267 | #define NEXT(cmd) ((Scsi_Cmnd *)((cmd)->host_scribble)) |
| 268 | #define NEXTADDR(cmd) ((Scsi_Cmnd **)&((cmd)->host_scribble)) |
| 269 | |
| 270 | #define HOSTNO instance->host_no |
| 271 | #define H_NO(cmd) (cmd)->device->host->host_no |
| 272 | |
| 273 | #ifdef SUPPORT_TAGS |
| 274 | |
| 275 | /* |
| 276 | * Functions for handling tagged queuing |
| 277 | * ===================================== |
| 278 | * |
| 279 | * ++roman (01/96): Now I've implemented SCSI-2 tagged queuing. Some notes: |
| 280 | * |
| 281 | * Using consecutive numbers for the tags is no good idea in my eyes. There |
| 282 | * could be wrong re-usings if the counter (8 bit!) wraps and some early |
| 283 | * command has been preempted for a long time. My solution: a bitfield for |
| 284 | * remembering used tags. |
| 285 | * |
| 286 | * There's also the problem that each target has a certain queue size, but we |
| 287 | * cannot know it in advance :-( We just see a QUEUE_FULL status being |
| 288 | * returned. So, in this case, the driver internal queue size assumption is |
| 289 | * reduced to the number of active tags if QUEUE_FULL is returned by the |
| 290 | * target. The command is returned to the mid-level, but with status changed |
| 291 | * to BUSY, since --as I've seen-- the mid-level can't handle QUEUE_FULL |
| 292 | * correctly. |
| 293 | * |
| 294 | * We're also not allowed running tagged commands as long as an untagged |
| 295 | * command is active. And REQUEST SENSE commands after a contingent allegiance |
| 296 | * condition _must_ be untagged. To keep track whether an untagged command has |
| 297 | * been issued, the host->busy array is still employed, as it is without |
| 298 | * support for tagged queuing. |
| 299 | * |
| 300 | * One could suspect that there are possible race conditions between |
| 301 | * is_lun_busy(), cmd_get_tag() and cmd_free_tag(). But I think this isn't the |
| 302 | * case: is_lun_busy() and cmd_get_tag() are both called from NCR5380_main(), |
| 303 | * which already guaranteed to be running at most once. It is also the only |
| 304 | * place where tags/LUNs are allocated. So no other allocation can slip |
| 305 | * between that pair, there could only happen a reselection, which can free a |
| 306 | * tag, but that doesn't hurt. Only the sequence in cmd_free_tag() becomes |
| 307 | * important: the tag bit must be cleared before 'nr_allocated' is decreased. |
| 308 | */ |
| 309 | |
| 310 | /* -1 for TAG_NONE is not possible with unsigned char cmd->tag */ |
| 311 | #undef TAG_NONE |
| 312 | #define TAG_NONE 0xff |
| 313 | |
| 314 | typedef struct { |
| 315 | DECLARE_BITMAP(allocated, MAX_TAGS); |
| 316 | int nr_allocated; |
| 317 | int queue_size; |
| 318 | } TAG_ALLOC; |
| 319 | |
| 320 | static TAG_ALLOC TagAlloc[8][8]; /* 8 targets and 8 LUNs */ |
| 321 | |
| 322 | |
| 323 | static void __init init_tags( void ) |
| 324 | { |
| 325 | int target, lun; |
| 326 | TAG_ALLOC *ta; |
| 327 | |
| 328 | if (!setup_use_tagged_queuing) |
| 329 | return; |
| 330 | |
| 331 | for( target = 0; target < 8; ++target ) { |
| 332 | for( lun = 0; lun < 8; ++lun ) { |
| 333 | ta = &TagAlloc[target][lun]; |
| 334 | bitmap_zero(ta->allocated, MAX_TAGS); |
| 335 | ta->nr_allocated = 0; |
| 336 | /* At the beginning, assume the maximum queue size we could |
| 337 | * support (MAX_TAGS). This value will be decreased if the target |
| 338 | * returns QUEUE_FULL status. |
| 339 | */ |
| 340 | ta->queue_size = MAX_TAGS; |
| 341 | } |
| 342 | } |
| 343 | } |
| 344 | |
| 345 | |
| 346 | /* Check if we can issue a command to this LUN: First see if the LUN is marked |
| 347 | * busy by an untagged command. If the command should use tagged queuing, also |
| 348 | * check that there is a free tag and the target's queue won't overflow. This |
| 349 | * function should be called with interrupts disabled to avoid race |
| 350 | * conditions. |
| 351 | */ |
| 352 | |
| 353 | static int is_lun_busy( Scsi_Cmnd *cmd, int should_be_tagged ) |
| 354 | { |
| 355 | SETUP_HOSTDATA(cmd->device->host); |
| 356 | |
| 357 | if (hostdata->busy[cmd->device->id] & (1 << cmd->device->lun)) |
| 358 | return( 1 ); |
| 359 | if (!should_be_tagged || |
| 360 | !setup_use_tagged_queuing || !cmd->device->tagged_supported) |
| 361 | return( 0 ); |
| 362 | if (TagAlloc[cmd->device->id][cmd->device->lun].nr_allocated >= |
| 363 | TagAlloc[cmd->device->id][cmd->device->lun].queue_size ) { |
| 364 | TAG_PRINTK( "scsi%d: target %d lun %d: no free tags\n", |
| 365 | H_NO(cmd), cmd->device->id, cmd->device->lun ); |
| 366 | return( 1 ); |
| 367 | } |
| 368 | return( 0 ); |
| 369 | } |
| 370 | |
| 371 | |
| 372 | /* Allocate a tag for a command (there are no checks anymore, check_lun_busy() |
| 373 | * must be called before!), or reserve the LUN in 'busy' if the command is |
| 374 | * untagged. |
| 375 | */ |
| 376 | |
| 377 | static void cmd_get_tag( Scsi_Cmnd *cmd, int should_be_tagged ) |
| 378 | { |
| 379 | SETUP_HOSTDATA(cmd->device->host); |
| 380 | |
| 381 | /* If we or the target don't support tagged queuing, allocate the LUN for |
| 382 | * an untagged command. |
| 383 | */ |
| 384 | if (!should_be_tagged || |
| 385 | !setup_use_tagged_queuing || !cmd->device->tagged_supported) { |
| 386 | cmd->tag = TAG_NONE; |
| 387 | hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun); |
| 388 | TAG_PRINTK( "scsi%d: target %d lun %d now allocated by untagged " |
| 389 | "command\n", H_NO(cmd), cmd->device->id, cmd->device->lun ); |
| 390 | } |
| 391 | else { |
| 392 | TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun]; |
| 393 | |
| 394 | cmd->tag = find_first_zero_bit( ta->allocated, MAX_TAGS ); |
| 395 | set_bit( cmd->tag, ta->allocated ); |
| 396 | ta->nr_allocated++; |
| 397 | TAG_PRINTK( "scsi%d: using tag %d for target %d lun %d " |
| 398 | "(now %d tags in use)\n", |
| 399 | H_NO(cmd), cmd->tag, cmd->device->id, cmd->device->lun, |
| 400 | ta->nr_allocated ); |
| 401 | } |
| 402 | } |
| 403 | |
| 404 | |
| 405 | /* Mark the tag of command 'cmd' as free, or in case of an untagged command, |
| 406 | * unlock the LUN. |
| 407 | */ |
| 408 | |
| 409 | static void cmd_free_tag( Scsi_Cmnd *cmd ) |
| 410 | { |
| 411 | SETUP_HOSTDATA(cmd->device->host); |
| 412 | |
| 413 | if (cmd->tag == TAG_NONE) { |
| 414 | hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun); |
| 415 | TAG_PRINTK( "scsi%d: target %d lun %d untagged cmd finished\n", |
| 416 | H_NO(cmd), cmd->device->id, cmd->device->lun ); |
| 417 | } |
| 418 | else if (cmd->tag >= MAX_TAGS) { |
| 419 | printk(KERN_NOTICE "scsi%d: trying to free bad tag %d!\n", |
| 420 | H_NO(cmd), cmd->tag ); |
| 421 | } |
| 422 | else { |
| 423 | TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun]; |
| 424 | clear_bit( cmd->tag, ta->allocated ); |
| 425 | ta->nr_allocated--; |
| 426 | TAG_PRINTK( "scsi%d: freed tag %d for target %d lun %d\n", |
| 427 | H_NO(cmd), cmd->tag, cmd->device->id, cmd->device->lun ); |
| 428 | } |
| 429 | } |
| 430 | |
| 431 | |
| 432 | static void free_all_tags( void ) |
| 433 | { |
| 434 | int target, lun; |
| 435 | TAG_ALLOC *ta; |
| 436 | |
| 437 | if (!setup_use_tagged_queuing) |
| 438 | return; |
| 439 | |
| 440 | for( target = 0; target < 8; ++target ) { |
| 441 | for( lun = 0; lun < 8; ++lun ) { |
| 442 | ta = &TagAlloc[target][lun]; |
| 443 | bitmap_zero(ta->allocated, MAX_TAGS); |
| 444 | ta->nr_allocated = 0; |
| 445 | } |
| 446 | } |
| 447 | } |
| 448 | |
| 449 | #endif /* SUPPORT_TAGS */ |
| 450 | |
| 451 | |
| 452 | /* |
| 453 | * Function: void merge_contiguous_buffers( Scsi_Cmnd *cmd ) |
| 454 | * |
| 455 | * Purpose: Try to merge several scatter-gather requests into one DMA |
| 456 | * transfer. This is possible if the scatter buffers lie on |
| 457 | * physical contiguous addresses. |
| 458 | * |
| 459 | * Parameters: Scsi_Cmnd *cmd |
| 460 | * The command to work on. The first scatter buffer's data are |
| 461 | * assumed to be already transfered into ptr/this_residual. |
| 462 | */ |
| 463 | |
| 464 | static void merge_contiguous_buffers( Scsi_Cmnd *cmd ) |
| 465 | { |
| 466 | unsigned long endaddr; |
| 467 | #if (NDEBUG & NDEBUG_MERGING) |
| 468 | unsigned long oldlen = cmd->SCp.this_residual; |
| 469 | int cnt = 1; |
| 470 | #endif |
| 471 | |
| 472 | for (endaddr = virt_to_phys(cmd->SCp.ptr + cmd->SCp.this_residual - 1) + 1; |
| 473 | cmd->SCp.buffers_residual && |
| 474 | virt_to_phys(page_address(cmd->SCp.buffer[1].page)+ |
| 475 | cmd->SCp.buffer[1].offset) == endaddr; ) { |
| 476 | MER_PRINTK("VTOP(%p) == %08lx -> merging\n", |
| 477 | cmd->SCp.buffer[1].address, endaddr); |
| 478 | #if (NDEBUG & NDEBUG_MERGING) |
| 479 | ++cnt; |
| 480 | #endif |
| 481 | ++cmd->SCp.buffer; |
| 482 | --cmd->SCp.buffers_residual; |
| 483 | cmd->SCp.this_residual += cmd->SCp.buffer->length; |
| 484 | endaddr += cmd->SCp.buffer->length; |
| 485 | } |
| 486 | #if (NDEBUG & NDEBUG_MERGING) |
| 487 | if (oldlen != cmd->SCp.this_residual) |
| 488 | MER_PRINTK("merged %d buffers from %p, new length %08x\n", |
| 489 | cnt, cmd->SCp.ptr, cmd->SCp.this_residual); |
| 490 | #endif |
| 491 | } |
| 492 | |
| 493 | /* |
| 494 | * Function : void initialize_SCp(Scsi_Cmnd *cmd) |
| 495 | * |
| 496 | * Purpose : initialize the saved data pointers for cmd to point to the |
| 497 | * start of the buffer. |
| 498 | * |
| 499 | * Inputs : cmd - Scsi_Cmnd structure to have pointers reset. |
| 500 | */ |
| 501 | |
| 502 | static __inline__ void initialize_SCp(Scsi_Cmnd *cmd) |
| 503 | { |
| 504 | /* |
| 505 | * Initialize the Scsi Pointer field so that all of the commands in the |
| 506 | * various queues are valid. |
| 507 | */ |
| 508 | |
| 509 | if (cmd->use_sg) { |
| 510 | cmd->SCp.buffer = (struct scatterlist *) cmd->request_buffer; |
| 511 | cmd->SCp.buffers_residual = cmd->use_sg - 1; |
| 512 | cmd->SCp.ptr = (char *)page_address(cmd->SCp.buffer->page)+ |
| 513 | cmd->SCp.buffer->offset; |
| 514 | cmd->SCp.this_residual = cmd->SCp.buffer->length; |
| 515 | /* ++roman: Try to merge some scatter-buffers if they are at |
| 516 | * contiguous physical addresses. |
| 517 | */ |
| 518 | merge_contiguous_buffers( cmd ); |
| 519 | } else { |
| 520 | cmd->SCp.buffer = NULL; |
| 521 | cmd->SCp.buffers_residual = 0; |
| 522 | cmd->SCp.ptr = (char *) cmd->request_buffer; |
| 523 | cmd->SCp.this_residual = cmd->request_bufflen; |
| 524 | } |
| 525 | } |
| 526 | |
| 527 | #include <linux/delay.h> |
| 528 | |
| 529 | #if NDEBUG |
| 530 | static struct { |
| 531 | unsigned char mask; |
| 532 | const char * name;} |
| 533 | signals[] = {{ SR_DBP, "PARITY"}, { SR_RST, "RST" }, { SR_BSY, "BSY" }, |
| 534 | { SR_REQ, "REQ" }, { SR_MSG, "MSG" }, { SR_CD, "CD" }, { SR_IO, "IO" }, |
| 535 | { SR_SEL, "SEL" }, {0, NULL}}, |
| 536 | basrs[] = {{BASR_ATN, "ATN"}, {BASR_ACK, "ACK"}, {0, NULL}}, |
| 537 | icrs[] = {{ICR_ASSERT_RST, "ASSERT RST"},{ICR_ASSERT_ACK, "ASSERT ACK"}, |
| 538 | {ICR_ASSERT_BSY, "ASSERT BSY"}, {ICR_ASSERT_SEL, "ASSERT SEL"}, |
| 539 | {ICR_ASSERT_ATN, "ASSERT ATN"}, {ICR_ASSERT_DATA, "ASSERT DATA"}, |
| 540 | {0, NULL}}, |
| 541 | mrs[] = {{MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"}, {MR_TARGET, "MODE TARGET"}, |
| 542 | {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, {MR_ENABLE_PAR_INTR, |
| 543 | "MODE PARITY INTR"}, {MR_ENABLE_EOP_INTR,"MODE EOP INTR"}, |
| 544 | {MR_MONITOR_BSY, "MODE MONITOR BSY"}, |
| 545 | {MR_DMA_MODE, "MODE DMA"}, {MR_ARBITRATE, "MODE ARBITRATION"}, |
| 546 | {0, NULL}}; |
| 547 | |
| 548 | /* |
| 549 | * Function : void NCR5380_print(struct Scsi_Host *instance) |
| 550 | * |
| 551 | * Purpose : print the SCSI bus signals for debugging purposes |
| 552 | * |
| 553 | * Input : instance - which NCR5380 |
| 554 | */ |
| 555 | |
| 556 | static void NCR5380_print(struct Scsi_Host *instance) { |
| 557 | unsigned char status, data, basr, mr, icr, i; |
| 558 | unsigned long flags; |
| 559 | |
| 560 | local_irq_save(flags); |
| 561 | data = NCR5380_read(CURRENT_SCSI_DATA_REG); |
| 562 | status = NCR5380_read(STATUS_REG); |
| 563 | mr = NCR5380_read(MODE_REG); |
| 564 | icr = NCR5380_read(INITIATOR_COMMAND_REG); |
| 565 | basr = NCR5380_read(BUS_AND_STATUS_REG); |
| 566 | local_irq_restore(flags); |
| 567 | printk("STATUS_REG: %02x ", status); |
| 568 | for (i = 0; signals[i].mask ; ++i) |
| 569 | if (status & signals[i].mask) |
| 570 | printk(",%s", signals[i].name); |
| 571 | printk("\nBASR: %02x ", basr); |
| 572 | for (i = 0; basrs[i].mask ; ++i) |
| 573 | if (basr & basrs[i].mask) |
| 574 | printk(",%s", basrs[i].name); |
| 575 | printk("\nICR: %02x ", icr); |
| 576 | for (i = 0; icrs[i].mask; ++i) |
| 577 | if (icr & icrs[i].mask) |
| 578 | printk(",%s", icrs[i].name); |
| 579 | printk("\nMODE: %02x ", mr); |
| 580 | for (i = 0; mrs[i].mask; ++i) |
| 581 | if (mr & mrs[i].mask) |
| 582 | printk(",%s", mrs[i].name); |
| 583 | printk("\n"); |
| 584 | } |
| 585 | |
| 586 | static struct { |
| 587 | unsigned char value; |
| 588 | const char *name; |
| 589 | } phases[] = { |
| 590 | {PHASE_DATAOUT, "DATAOUT"}, {PHASE_DATAIN, "DATAIN"}, {PHASE_CMDOUT, "CMDOUT"}, |
| 591 | {PHASE_STATIN, "STATIN"}, {PHASE_MSGOUT, "MSGOUT"}, {PHASE_MSGIN, "MSGIN"}, |
| 592 | {PHASE_UNKNOWN, "UNKNOWN"}}; |
| 593 | |
| 594 | /* |
| 595 | * Function : void NCR5380_print_phase(struct Scsi_Host *instance) |
| 596 | * |
| 597 | * Purpose : print the current SCSI phase for debugging purposes |
| 598 | * |
| 599 | * Input : instance - which NCR5380 |
| 600 | */ |
| 601 | |
| 602 | static void NCR5380_print_phase(struct Scsi_Host *instance) |
| 603 | { |
| 604 | unsigned char status; |
| 605 | int i; |
| 606 | |
| 607 | status = NCR5380_read(STATUS_REG); |
| 608 | if (!(status & SR_REQ)) |
| 609 | printk(KERN_DEBUG "scsi%d: REQ not asserted, phase unknown.\n", HOSTNO); |
| 610 | else { |
| 611 | for (i = 0; (phases[i].value != PHASE_UNKNOWN) && |
| 612 | (phases[i].value != (status & PHASE_MASK)); ++i); |
| 613 | printk(KERN_DEBUG "scsi%d: phase %s\n", HOSTNO, phases[i].name); |
| 614 | } |
| 615 | } |
| 616 | |
| 617 | #else /* !NDEBUG */ |
| 618 | |
| 619 | /* dummies... */ |
| 620 | __inline__ void NCR5380_print(struct Scsi_Host *instance) { }; |
| 621 | __inline__ void NCR5380_print_phase(struct Scsi_Host *instance) { }; |
| 622 | |
| 623 | #endif |
| 624 | |
| 625 | /* |
| 626 | * ++roman: New scheme of calling NCR5380_main() |
| 627 | * |
| 628 | * If we're not in an interrupt, we can call our main directly, it cannot be |
| 629 | * already running. Else, we queue it on a task queue, if not 'main_running' |
| 630 | * tells us that a lower level is already executing it. This way, |
| 631 | * 'main_running' needs not be protected in a special way. |
| 632 | * |
| 633 | * queue_main() is a utility function for putting our main onto the task |
| 634 | * queue, if main_running is false. It should be called only from a |
| 635 | * interrupt or bottom half. |
| 636 | */ |
| 637 | |
| 638 | #include <linux/workqueue.h> |
| 639 | #include <linux/interrupt.h> |
| 640 | |
| 641 | static volatile int main_running = 0; |
| 642 | static DECLARE_WORK(NCR5380_tqueue, (void (*)(void*))NCR5380_main, NULL); |
| 643 | |
| 644 | static __inline__ void queue_main(void) |
| 645 | { |
| 646 | if (!main_running) { |
| 647 | /* If in interrupt and NCR5380_main() not already running, |
| 648 | queue it on the 'immediate' task queue, to be processed |
| 649 | immediately after the current interrupt processing has |
| 650 | finished. */ |
| 651 | schedule_work(&NCR5380_tqueue); |
| 652 | } |
| 653 | /* else: nothing to do: the running NCR5380_main() will pick up |
| 654 | any newly queued command. */ |
| 655 | } |
| 656 | |
| 657 | |
| 658 | static inline void NCR5380_all_init (void) |
| 659 | { |
| 660 | static int done = 0; |
| 661 | if (!done) { |
| 662 | INI_PRINTK("scsi : NCR5380_all_init()\n"); |
| 663 | done = 1; |
| 664 | } |
| 665 | } |
| 666 | |
| 667 | |
| 668 | /* |
| 669 | * Function : void NCR58380_print_options (struct Scsi_Host *instance) |
| 670 | * |
| 671 | * Purpose : called by probe code indicating the NCR5380 driver |
| 672 | * options that were selected. |
| 673 | * |
| 674 | * Inputs : instance, pointer to this instance. Unused. |
| 675 | */ |
| 676 | |
| 677 | static void __init NCR5380_print_options (struct Scsi_Host *instance) |
| 678 | { |
| 679 | printk(" generic options" |
| 680 | #ifdef AUTOSENSE |
| 681 | " AUTOSENSE" |
| 682 | #endif |
| 683 | #ifdef REAL_DMA |
| 684 | " REAL DMA" |
| 685 | #endif |
| 686 | #ifdef PARITY |
| 687 | " PARITY" |
| 688 | #endif |
| 689 | #ifdef SUPPORT_TAGS |
| 690 | " SCSI-2 TAGGED QUEUING" |
| 691 | #endif |
| 692 | ); |
| 693 | printk(" generic release=%d", NCR5380_PUBLIC_RELEASE); |
| 694 | } |
| 695 | |
| 696 | /* |
| 697 | * Function : void NCR5380_print_status (struct Scsi_Host *instance) |
| 698 | * |
| 699 | * Purpose : print commands in the various queues, called from |
| 700 | * NCR5380_abort and NCR5380_debug to aid debugging. |
| 701 | * |
| 702 | * Inputs : instance, pointer to this instance. |
| 703 | */ |
| 704 | |
| 705 | static void NCR5380_print_status (struct Scsi_Host *instance) |
| 706 | { |
| 707 | char *pr_bfr; |
| 708 | char *start; |
| 709 | int len; |
| 710 | |
| 711 | NCR_PRINT(NDEBUG_ANY); |
| 712 | NCR_PRINT_PHASE(NDEBUG_ANY); |
| 713 | |
| 714 | pr_bfr = (char *) __get_free_page(GFP_ATOMIC); |
| 715 | if (!pr_bfr) { |
| 716 | printk("NCR5380_print_status: no memory for print buffer\n"); |
| 717 | return; |
| 718 | } |
| 719 | len = NCR5380_proc_info(pr_bfr, &start, 0, PAGE_SIZE, HOSTNO, 0); |
| 720 | pr_bfr[len] = 0; |
| 721 | printk("\n%s\n", pr_bfr); |
| 722 | free_page((unsigned long) pr_bfr); |
| 723 | } |
| 724 | |
| 725 | |
| 726 | /******************************************/ |
| 727 | /* |
| 728 | * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED] |
| 729 | * |
| 730 | * *buffer: I/O buffer |
| 731 | * **start: if inout == FALSE pointer into buffer where user read should start |
| 732 | * offset: current offset |
| 733 | * length: length of buffer |
| 734 | * hostno: Scsi_Host host_no |
| 735 | * inout: TRUE - user is writing; FALSE - user is reading |
| 736 | * |
| 737 | * Return the number of bytes read from or written |
| 738 | */ |
| 739 | |
| 740 | #undef SPRINTF |
| 741 | #define SPRINTF(fmt,args...) \ |
| 742 | do { if (pos + strlen(fmt) + 20 /* slop */ < buffer + length) \ |
| 743 | pos += sprintf(pos, fmt , ## args); } while(0) |
| 744 | static |
| 745 | char *lprint_Scsi_Cmnd (Scsi_Cmnd *cmd, char *pos, char *buffer, int length); |
| 746 | |
| 747 | static |
| 748 | int NCR5380_proc_info (struct Scsi_Host *instance, char *buffer, char **start, off_t offset, |
| 749 | int length, int inout) |
| 750 | { |
| 751 | char *pos = buffer; |
| 752 | struct NCR5380_hostdata *hostdata; |
| 753 | Scsi_Cmnd *ptr; |
| 754 | unsigned long flags; |
| 755 | off_t begin = 0; |
| 756 | #define check_offset() \ |
| 757 | do { \ |
| 758 | if (pos - buffer < offset - begin) { \ |
| 759 | begin += pos - buffer; \ |
| 760 | pos = buffer; \ |
| 761 | } \ |
| 762 | } while (0) |
| 763 | |
| 764 | hostdata = (struct NCR5380_hostdata *)instance->hostdata; |
| 765 | |
| 766 | if (inout) { /* Has data been written to the file ? */ |
| 767 | return(-ENOSYS); /* Currently this is a no-op */ |
| 768 | } |
| 769 | SPRINTF("NCR5380 core release=%d.\n", NCR5380_PUBLIC_RELEASE); |
| 770 | check_offset(); |
| 771 | local_irq_save(flags); |
| 772 | SPRINTF("NCR5380: coroutine is%s running.\n", main_running ? "" : "n't"); |
| 773 | check_offset(); |
| 774 | if (!hostdata->connected) |
| 775 | SPRINTF("scsi%d: no currently connected command\n", HOSTNO); |
| 776 | else |
| 777 | pos = lprint_Scsi_Cmnd ((Scsi_Cmnd *) hostdata->connected, |
| 778 | pos, buffer, length); |
| 779 | SPRINTF("scsi%d: issue_queue\n", HOSTNO); |
| 780 | check_offset(); |
| 781 | for (ptr = (Scsi_Cmnd *) hostdata->issue_queue; ptr; ptr = NEXT(ptr)) { |
| 782 | pos = lprint_Scsi_Cmnd (ptr, pos, buffer, length); |
| 783 | check_offset(); |
| 784 | } |
| 785 | |
| 786 | SPRINTF("scsi%d: disconnected_queue\n", HOSTNO); |
| 787 | check_offset(); |
| 788 | for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr; |
| 789 | ptr = NEXT(ptr)) { |
| 790 | pos = lprint_Scsi_Cmnd (ptr, pos, buffer, length); |
| 791 | check_offset(); |
| 792 | } |
| 793 | |
| 794 | local_irq_restore(flags); |
| 795 | *start = buffer + (offset - begin); |
| 796 | if (pos - buffer < offset - begin) |
| 797 | return 0; |
| 798 | else if (pos - buffer - (offset - begin) < length) |
| 799 | return pos - buffer - (offset - begin); |
| 800 | return length; |
| 801 | } |
| 802 | |
| 803 | static char * |
| 804 | lprint_Scsi_Cmnd (Scsi_Cmnd *cmd, char *pos, char *buffer, int length) |
| 805 | { |
| 806 | int i, s; |
| 807 | unsigned char *command; |
| 808 | SPRINTF("scsi%d: destination target %d, lun %d\n", |
| 809 | H_NO(cmd), cmd->device->id, cmd->device->lun); |
| 810 | SPRINTF(" command = "); |
| 811 | command = cmd->cmnd; |
| 812 | SPRINTF("%2d (0x%02x)", command[0], command[0]); |
| 813 | for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i) |
| 814 | SPRINTF(" %02x", command[i]); |
| 815 | SPRINTF("\n"); |
| 816 | return pos; |
| 817 | } |
| 818 | |
| 819 | |
| 820 | /* |
| 821 | * Function : void NCR5380_init (struct Scsi_Host *instance) |
| 822 | * |
| 823 | * Purpose : initializes *instance and corresponding 5380 chip. |
| 824 | * |
| 825 | * Inputs : instance - instantiation of the 5380 driver. |
| 826 | * |
| 827 | * Notes : I assume that the host, hostno, and id bits have been |
| 828 | * set correctly. I don't care about the irq and other fields. |
| 829 | * |
| 830 | */ |
| 831 | |
| 832 | static int NCR5380_init (struct Scsi_Host *instance, int flags) |
| 833 | { |
| 834 | int i; |
| 835 | SETUP_HOSTDATA(instance); |
| 836 | |
| 837 | NCR5380_all_init(); |
| 838 | |
| 839 | hostdata->aborted = 0; |
| 840 | hostdata->id_mask = 1 << instance->this_id; |
| 841 | hostdata->id_higher_mask = 0; |
| 842 | for (i = hostdata->id_mask; i <= 0x80; i <<= 1) |
| 843 | if (i > hostdata->id_mask) |
| 844 | hostdata->id_higher_mask |= i; |
| 845 | for (i = 0; i < 8; ++i) |
| 846 | hostdata->busy[i] = 0; |
| 847 | #ifdef SUPPORT_TAGS |
| 848 | init_tags(); |
| 849 | #endif |
| 850 | #if defined (REAL_DMA) |
| 851 | hostdata->dma_len = 0; |
| 852 | #endif |
| 853 | hostdata->targets_present = 0; |
| 854 | hostdata->connected = NULL; |
| 855 | hostdata->issue_queue = NULL; |
| 856 | hostdata->disconnected_queue = NULL; |
| 857 | hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT; |
| 858 | |
| 859 | if (!the_template) { |
| 860 | the_template = instance->hostt; |
| 861 | first_instance = instance; |
| 862 | } |
| 863 | |
| 864 | |
| 865 | #ifndef AUTOSENSE |
| 866 | if ((instance->cmd_per_lun > 1) || (instance->can_queue > 1)) |
| 867 | printk("scsi%d: WARNING : support for multiple outstanding commands enabled\n" |
| 868 | " without AUTOSENSE option, contingent allegiance conditions may\n" |
| 869 | " be incorrectly cleared.\n", HOSTNO); |
| 870 | #endif /* def AUTOSENSE */ |
| 871 | |
| 872 | NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); |
| 873 | NCR5380_write(MODE_REG, MR_BASE); |
| 874 | NCR5380_write(TARGET_COMMAND_REG, 0); |
| 875 | NCR5380_write(SELECT_ENABLE_REG, 0); |
| 876 | |
| 877 | return 0; |
| 878 | } |
| 879 | |
| 880 | /* |
| 881 | * Function : int NCR5380_queue_command (Scsi_Cmnd *cmd, |
| 882 | * void (*done)(Scsi_Cmnd *)) |
| 883 | * |
| 884 | * Purpose : enqueues a SCSI command |
| 885 | * |
| 886 | * Inputs : cmd - SCSI command, done - function called on completion, with |
| 887 | * a pointer to the command descriptor. |
| 888 | * |
| 889 | * Returns : 0 |
| 890 | * |
| 891 | * Side effects : |
| 892 | * cmd is added to the per instance issue_queue, with minor |
| 893 | * twiddling done to the host specific fields of cmd. If the |
| 894 | * main coroutine is not running, it is restarted. |
| 895 | * |
| 896 | */ |
| 897 | |
| 898 | static |
| 899 | int NCR5380_queue_command (Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *)) |
| 900 | { |
| 901 | SETUP_HOSTDATA(cmd->device->host); |
| 902 | Scsi_Cmnd *tmp; |
| 903 | int oldto; |
| 904 | unsigned long flags; |
| 905 | extern int update_timeout(Scsi_Cmnd * SCset, int timeout); |
| 906 | |
| 907 | #if (NDEBUG & NDEBUG_NO_WRITE) |
| 908 | switch (cmd->cmnd[0]) { |
| 909 | case WRITE_6: |
| 910 | case WRITE_10: |
| 911 | printk(KERN_NOTICE "scsi%d: WRITE attempted with NO_WRITE debugging flag set\n", |
| 912 | H_NO(cmd)); |
| 913 | cmd->result = (DID_ERROR << 16); |
| 914 | done(cmd); |
| 915 | return 0; |
| 916 | } |
| 917 | #endif /* (NDEBUG & NDEBUG_NO_WRITE) */ |
| 918 | |
| 919 | |
| 920 | #ifdef NCR5380_STATS |
| 921 | # if 0 |
| 922 | if (!hostdata->connected && !hostdata->issue_queue && |
| 923 | !hostdata->disconnected_queue) { |
| 924 | hostdata->timebase = jiffies; |
| 925 | } |
| 926 | # endif |
| 927 | # ifdef NCR5380_STAT_LIMIT |
| 928 | if (cmd->request_bufflen > NCR5380_STAT_LIMIT) |
| 929 | # endif |
| 930 | switch (cmd->cmnd[0]) |
| 931 | { |
| 932 | case WRITE: |
| 933 | case WRITE_6: |
| 934 | case WRITE_10: |
| 935 | hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase); |
| 936 | hostdata->bytes_write[cmd->device->id] += cmd->request_bufflen; |
| 937 | hostdata->pendingw++; |
| 938 | break; |
| 939 | case READ: |
| 940 | case READ_6: |
| 941 | case READ_10: |
| 942 | hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase); |
| 943 | hostdata->bytes_read[cmd->device->id] += cmd->request_bufflen; |
| 944 | hostdata->pendingr++; |
| 945 | break; |
| 946 | } |
| 947 | #endif |
| 948 | |
| 949 | /* |
| 950 | * We use the host_scribble field as a pointer to the next command |
| 951 | * in a queue |
| 952 | */ |
| 953 | |
| 954 | NEXT(cmd) = NULL; |
| 955 | cmd->scsi_done = done; |
| 956 | |
| 957 | cmd->result = 0; |
| 958 | |
| 959 | |
| 960 | /* |
| 961 | * Insert the cmd into the issue queue. Note that REQUEST SENSE |
| 962 | * commands are added to the head of the queue since any command will |
| 963 | * clear the contingent allegiance condition that exists and the |
| 964 | * sense data is only guaranteed to be valid while the condition exists. |
| 965 | */ |
| 966 | |
| 967 | local_irq_save(flags); |
| 968 | /* ++guenther: now that the issue queue is being set up, we can lock ST-DMA. |
| 969 | * Otherwise a running NCR5380_main may steal the lock. |
| 970 | * Lock before actually inserting due to fairness reasons explained in |
| 971 | * atari_scsi.c. If we insert first, then it's impossible for this driver |
| 972 | * to release the lock. |
| 973 | * Stop timer for this command while waiting for the lock, or timeouts |
| 974 | * may happen (and they really do), and it's no good if the command doesn't |
| 975 | * appear in any of the queues. |
| 976 | * ++roman: Just disabling the NCR interrupt isn't sufficient here, |
| 977 | * because also a timer int can trigger an abort or reset, which would |
| 978 | * alter queues and touch the lock. |
| 979 | */ |
| 980 | if (!IS_A_TT()) { |
| 981 | oldto = update_timeout(cmd, 0); |
| 982 | falcon_get_lock(); |
| 983 | update_timeout(cmd, oldto); |
| 984 | } |
| 985 | if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) { |
| 986 | LIST(cmd, hostdata->issue_queue); |
| 987 | NEXT(cmd) = hostdata->issue_queue; |
| 988 | hostdata->issue_queue = cmd; |
| 989 | } else { |
| 990 | for (tmp = (Scsi_Cmnd *)hostdata->issue_queue; |
| 991 | NEXT(tmp); tmp = NEXT(tmp)) |
| 992 | ; |
| 993 | LIST(cmd, tmp); |
| 994 | NEXT(tmp) = cmd; |
| 995 | } |
| 996 | local_irq_restore(flags); |
| 997 | |
| 998 | QU_PRINTK("scsi%d: command added to %s of queue\n", H_NO(cmd), |
| 999 | (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail"); |
| 1000 | |
| 1001 | /* If queue_command() is called from an interrupt (real one or bottom |
| 1002 | * half), we let queue_main() do the job of taking care about main. If it |
| 1003 | * is already running, this is a no-op, else main will be queued. |
| 1004 | * |
| 1005 | * If we're not in an interrupt, we can call NCR5380_main() |
| 1006 | * unconditionally, because it cannot be already running. |
| 1007 | */ |
| 1008 | if (in_interrupt() || ((flags >> 8) & 7) >= 6) |
| 1009 | queue_main(); |
| 1010 | else |
| 1011 | NCR5380_main(NULL); |
| 1012 | return 0; |
| 1013 | } |
| 1014 | |
| 1015 | /* |
| 1016 | * Function : NCR5380_main (void) |
| 1017 | * |
| 1018 | * Purpose : NCR5380_main is a coroutine that runs as long as more work can |
| 1019 | * be done on the NCR5380 host adapters in a system. Both |
| 1020 | * NCR5380_queue_command() and NCR5380_intr() will try to start it |
| 1021 | * in case it is not running. |
| 1022 | * |
| 1023 | * NOTE : NCR5380_main exits with interrupts *disabled*, the caller should |
| 1024 | * reenable them. This prevents reentrancy and kernel stack overflow. |
| 1025 | */ |
| 1026 | |
| 1027 | static void NCR5380_main (void *bl) |
| 1028 | { |
| 1029 | Scsi_Cmnd *tmp, *prev; |
| 1030 | struct Scsi_Host *instance = first_instance; |
| 1031 | struct NCR5380_hostdata *hostdata = HOSTDATA(instance); |
| 1032 | int done; |
| 1033 | unsigned long flags; |
| 1034 | |
| 1035 | /* |
| 1036 | * We run (with interrupts disabled) until we're sure that none of |
| 1037 | * the host adapters have anything that can be done, at which point |
| 1038 | * we set main_running to 0 and exit. |
| 1039 | * |
| 1040 | * Interrupts are enabled before doing various other internal |
| 1041 | * instructions, after we've decided that we need to run through |
| 1042 | * the loop again. |
| 1043 | * |
| 1044 | * this should prevent any race conditions. |
| 1045 | * |
| 1046 | * ++roman: Just disabling the NCR interrupt isn't sufficient here, |
| 1047 | * because also a timer int can trigger an abort or reset, which can |
| 1048 | * alter queues and touch the Falcon lock. |
| 1049 | */ |
| 1050 | |
| 1051 | /* Tell int handlers main() is now already executing. Note that |
| 1052 | no races are possible here. If an int comes in before |
| 1053 | 'main_running' is set here, and queues/executes main via the |
| 1054 | task queue, it doesn't do any harm, just this instance of main |
| 1055 | won't find any work left to do. */ |
| 1056 | if (main_running) |
| 1057 | return; |
| 1058 | main_running = 1; |
| 1059 | |
| 1060 | local_save_flags(flags); |
| 1061 | do { |
| 1062 | local_irq_disable(); /* Freeze request queues */ |
| 1063 | done = 1; |
| 1064 | |
| 1065 | if (!hostdata->connected) { |
| 1066 | MAIN_PRINTK( "scsi%d: not connected\n", HOSTNO ); |
| 1067 | /* |
| 1068 | * Search through the issue_queue for a command destined |
| 1069 | * for a target that's not busy. |
| 1070 | */ |
| 1071 | #if (NDEBUG & NDEBUG_LISTS) |
| 1072 | for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL; |
| 1073 | tmp && (tmp != prev); prev = tmp, tmp = NEXT(tmp)) |
| 1074 | ; |
| 1075 | /*printk("%p ", tmp);*/ |
| 1076 | if ((tmp == prev) && tmp) printk(" LOOP\n");/* else printk("\n");*/ |
| 1077 | #endif |
| 1078 | for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, |
| 1079 | prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp) ) { |
| 1080 | |
| 1081 | #if (NDEBUG & NDEBUG_LISTS) |
| 1082 | if (prev != tmp) |
| 1083 | printk("MAIN tmp=%p target=%d busy=%d lun=%d\n", |
| 1084 | tmp, tmp->device->id, hostdata->busy[tmp->device->id], |
| 1085 | tmp->device->lun); |
| 1086 | #endif |
| 1087 | /* When we find one, remove it from the issue queue. */ |
| 1088 | /* ++guenther: possible race with Falcon locking */ |
| 1089 | if ( |
| 1090 | #ifdef SUPPORT_TAGS |
| 1091 | !is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE) |
| 1092 | #else |
| 1093 | !(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun)) |
| 1094 | #endif |
| 1095 | ) { |
| 1096 | /* ++guenther: just to be sure, this must be atomic */ |
| 1097 | local_irq_disable(); |
| 1098 | if (prev) { |
| 1099 | REMOVE(prev, NEXT(prev), tmp, NEXT(tmp)); |
| 1100 | NEXT(prev) = NEXT(tmp); |
| 1101 | } else { |
| 1102 | REMOVE(-1, hostdata->issue_queue, tmp, NEXT(tmp)); |
| 1103 | hostdata->issue_queue = NEXT(tmp); |
| 1104 | } |
| 1105 | NEXT(tmp) = NULL; |
| 1106 | falcon_dont_release++; |
| 1107 | |
| 1108 | /* reenable interrupts after finding one */ |
| 1109 | local_irq_restore(flags); |
| 1110 | |
| 1111 | /* |
| 1112 | * Attempt to establish an I_T_L nexus here. |
| 1113 | * On success, instance->hostdata->connected is set. |
| 1114 | * On failure, we must add the command back to the |
| 1115 | * issue queue so we can keep trying. |
| 1116 | */ |
| 1117 | MAIN_PRINTK("scsi%d: main(): command for target %d " |
| 1118 | "lun %d removed from issue_queue\n", |
| 1119 | HOSTNO, tmp->device->id, tmp->device->lun); |
| 1120 | /* |
| 1121 | * REQUEST SENSE commands are issued without tagged |
| 1122 | * queueing, even on SCSI-II devices because the |
| 1123 | * contingent allegiance condition exists for the |
| 1124 | * entire unit. |
| 1125 | */ |
| 1126 | /* ++roman: ...and the standard also requires that |
| 1127 | * REQUEST SENSE command are untagged. |
| 1128 | */ |
| 1129 | |
| 1130 | #ifdef SUPPORT_TAGS |
| 1131 | cmd_get_tag( tmp, tmp->cmnd[0] != REQUEST_SENSE ); |
| 1132 | #endif |
| 1133 | if (!NCR5380_select(instance, tmp, |
| 1134 | (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE : |
| 1135 | TAG_NEXT)) { |
| 1136 | falcon_dont_release--; |
| 1137 | /* release if target did not response! */ |
| 1138 | falcon_release_lock_if_possible( hostdata ); |
| 1139 | break; |
| 1140 | } else { |
| 1141 | local_irq_disable(); |
| 1142 | LIST(tmp, hostdata->issue_queue); |
| 1143 | NEXT(tmp) = hostdata->issue_queue; |
| 1144 | hostdata->issue_queue = tmp; |
| 1145 | #ifdef SUPPORT_TAGS |
| 1146 | cmd_free_tag( tmp ); |
| 1147 | #endif |
| 1148 | falcon_dont_release--; |
| 1149 | local_irq_restore(flags); |
| 1150 | MAIN_PRINTK("scsi%d: main(): select() failed, " |
| 1151 | "returned to issue_queue\n", HOSTNO); |
| 1152 | if (hostdata->connected) |
| 1153 | break; |
| 1154 | } |
| 1155 | } /* if target/lun/target queue is not busy */ |
| 1156 | } /* for issue_queue */ |
| 1157 | } /* if (!hostdata->connected) */ |
| 1158 | |
| 1159 | if (hostdata->connected |
| 1160 | #ifdef REAL_DMA |
| 1161 | && !hostdata->dma_len |
| 1162 | #endif |
| 1163 | ) { |
| 1164 | local_irq_restore(flags); |
| 1165 | MAIN_PRINTK("scsi%d: main: performing information transfer\n", |
| 1166 | HOSTNO); |
| 1167 | NCR5380_information_transfer(instance); |
| 1168 | MAIN_PRINTK("scsi%d: main: done set false\n", HOSTNO); |
| 1169 | done = 0; |
| 1170 | } |
| 1171 | } while (!done); |
| 1172 | |
| 1173 | /* Better allow ints _after_ 'main_running' has been cleared, else |
| 1174 | an interrupt could believe we'll pick up the work it left for |
| 1175 | us, but we won't see it anymore here... */ |
| 1176 | main_running = 0; |
| 1177 | local_irq_restore(flags); |
| 1178 | } |
| 1179 | |
| 1180 | |
| 1181 | #ifdef REAL_DMA |
| 1182 | /* |
| 1183 | * Function : void NCR5380_dma_complete (struct Scsi_Host *instance) |
| 1184 | * |
| 1185 | * Purpose : Called by interrupt handler when DMA finishes or a phase |
| 1186 | * mismatch occurs (which would finish the DMA transfer). |
| 1187 | * |
| 1188 | * Inputs : instance - this instance of the NCR5380. |
| 1189 | * |
| 1190 | */ |
| 1191 | |
| 1192 | static void NCR5380_dma_complete( struct Scsi_Host *instance ) |
| 1193 | { |
| 1194 | SETUP_HOSTDATA(instance); |
| 1195 | int transfered, saved_data = 0, overrun = 0, cnt, toPIO; |
| 1196 | unsigned char **data, p; |
| 1197 | volatile int *count; |
| 1198 | |
| 1199 | if (!hostdata->connected) { |
| 1200 | printk(KERN_WARNING "scsi%d: received end of DMA interrupt with " |
| 1201 | "no connected cmd\n", HOSTNO); |
| 1202 | return; |
| 1203 | } |
| 1204 | |
| 1205 | if (atari_read_overruns) { |
| 1206 | p = hostdata->connected->SCp.phase; |
| 1207 | if (p & SR_IO) { |
| 1208 | udelay(10); |
| 1209 | if ((((NCR5380_read(BUS_AND_STATUS_REG)) & |
| 1210 | (BASR_PHASE_MATCH|BASR_ACK)) == |
| 1211 | (BASR_PHASE_MATCH|BASR_ACK))) { |
| 1212 | saved_data = NCR5380_read(INPUT_DATA_REG); |
| 1213 | overrun = 1; |
| 1214 | DMA_PRINTK("scsi%d: read overrun handled\n", HOSTNO); |
| 1215 | } |
| 1216 | } |
| 1217 | } |
| 1218 | |
| 1219 | DMA_PRINTK("scsi%d: real DMA transfer complete, basr 0x%X, sr 0x%X\n", |
| 1220 | HOSTNO, NCR5380_read(BUS_AND_STATUS_REG), |
| 1221 | NCR5380_read(STATUS_REG)); |
| 1222 | |
| 1223 | (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG); |
| 1224 | NCR5380_write(MODE_REG, MR_BASE); |
| 1225 | NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); |
| 1226 | |
| 1227 | transfered = hostdata->dma_len - NCR5380_dma_residual(instance); |
| 1228 | hostdata->dma_len = 0; |
| 1229 | |
| 1230 | data = (unsigned char **) &(hostdata->connected->SCp.ptr); |
| 1231 | count = &(hostdata->connected->SCp.this_residual); |
| 1232 | *data += transfered; |
| 1233 | *count -= transfered; |
| 1234 | |
| 1235 | if (atari_read_overruns) { |
| 1236 | if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) { |
| 1237 | cnt = toPIO = atari_read_overruns; |
| 1238 | if (overrun) { |
| 1239 | DMA_PRINTK("Got an input overrun, using saved byte\n"); |
| 1240 | *(*data)++ = saved_data; |
| 1241 | (*count)--; |
| 1242 | cnt--; |
| 1243 | toPIO--; |
| 1244 | } |
| 1245 | DMA_PRINTK("Doing %d-byte PIO to 0x%08lx\n", cnt, (long)*data); |
| 1246 | NCR5380_transfer_pio(instance, &p, &cnt, data); |
| 1247 | *count -= toPIO - cnt; |
| 1248 | } |
| 1249 | } |
| 1250 | } |
| 1251 | #endif /* REAL_DMA */ |
| 1252 | |
| 1253 | |
| 1254 | /* |
| 1255 | * Function : void NCR5380_intr (int irq) |
| 1256 | * |
| 1257 | * Purpose : handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses |
| 1258 | * from the disconnected queue, and restarting NCR5380_main() |
| 1259 | * as required. |
| 1260 | * |
| 1261 | * Inputs : int irq, irq that caused this interrupt. |
| 1262 | * |
| 1263 | */ |
| 1264 | |
| 1265 | static irqreturn_t NCR5380_intr (int irq, void *dev_id) |
| 1266 | { |
| 1267 | struct Scsi_Host *instance = first_instance; |
| 1268 | int done = 1, handled = 0; |
| 1269 | unsigned char basr; |
| 1270 | |
| 1271 | INT_PRINTK("scsi%d: NCR5380 irq triggered\n", HOSTNO); |
| 1272 | |
| 1273 | /* Look for pending interrupts */ |
| 1274 | basr = NCR5380_read(BUS_AND_STATUS_REG); |
| 1275 | INT_PRINTK("scsi%d: BASR=%02x\n", HOSTNO, basr); |
| 1276 | /* dispatch to appropriate routine if found and done=0 */ |
| 1277 | if (basr & BASR_IRQ) { |
| 1278 | NCR_PRINT(NDEBUG_INTR); |
| 1279 | if ((NCR5380_read(STATUS_REG) & (SR_SEL|SR_IO)) == (SR_SEL|SR_IO)) { |
| 1280 | done = 0; |
| 1281 | ENABLE_IRQ(); |
| 1282 | INT_PRINTK("scsi%d: SEL interrupt\n", HOSTNO); |
| 1283 | NCR5380_reselect(instance); |
| 1284 | (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG); |
| 1285 | } |
| 1286 | else if (basr & BASR_PARITY_ERROR) { |
| 1287 | INT_PRINTK("scsi%d: PARITY interrupt\n", HOSTNO); |
| 1288 | (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG); |
| 1289 | } |
| 1290 | else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) { |
| 1291 | INT_PRINTK("scsi%d: RESET interrupt\n", HOSTNO); |
| 1292 | (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG); |
| 1293 | } |
| 1294 | else { |
| 1295 | /* |
| 1296 | * The rest of the interrupt conditions can occur only during a |
| 1297 | * DMA transfer |
| 1298 | */ |
| 1299 | |
| 1300 | #if defined(REAL_DMA) |
| 1301 | /* |
| 1302 | * We should only get PHASE MISMATCH and EOP interrupts if we have |
| 1303 | * DMA enabled, so do a sanity check based on the current setting |
| 1304 | * of the MODE register. |
| 1305 | */ |
| 1306 | |
| 1307 | if ((NCR5380_read(MODE_REG) & MR_DMA_MODE) && |
| 1308 | ((basr & BASR_END_DMA_TRANSFER) || |
| 1309 | !(basr & BASR_PHASE_MATCH))) { |
| 1310 | |
| 1311 | INT_PRINTK("scsi%d: PHASE MISM or EOP interrupt\n", HOSTNO); |
| 1312 | NCR5380_dma_complete( instance ); |
| 1313 | done = 0; |
| 1314 | ENABLE_IRQ(); |
| 1315 | } else |
| 1316 | #endif /* REAL_DMA */ |
| 1317 | { |
| 1318 | /* MS: Ignore unknown phase mismatch interrupts (caused by EOP interrupt) */ |
| 1319 | if (basr & BASR_PHASE_MATCH) |
| 1320 | printk(KERN_NOTICE "scsi%d: unknown interrupt, " |
| 1321 | "BASR 0x%x, MR 0x%x, SR 0x%x\n", |
| 1322 | HOSTNO, basr, NCR5380_read(MODE_REG), |
| 1323 | NCR5380_read(STATUS_REG)); |
| 1324 | (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG); |
| 1325 | } |
| 1326 | } /* if !(SELECTION || PARITY) */ |
| 1327 | handled = 1; |
| 1328 | } /* BASR & IRQ */ |
| 1329 | else { |
| 1330 | printk(KERN_NOTICE "scsi%d: interrupt without IRQ bit set in BASR, " |
| 1331 | "BASR 0x%X, MR 0x%X, SR 0x%x\n", HOSTNO, basr, |
| 1332 | NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG)); |
| 1333 | (void) NCR5380_read(RESET_PARITY_INTERRUPT_REG); |
| 1334 | } |
| 1335 | |
| 1336 | if (!done) { |
| 1337 | INT_PRINTK("scsi%d: in int routine, calling main\n", HOSTNO); |
| 1338 | /* Put a call to NCR5380_main() on the queue... */ |
| 1339 | queue_main(); |
| 1340 | } |
| 1341 | return IRQ_RETVAL(handled); |
| 1342 | } |
| 1343 | |
| 1344 | #ifdef NCR5380_STATS |
| 1345 | static void collect_stats(struct NCR5380_hostdata* hostdata, Scsi_Cmnd* cmd) |
| 1346 | { |
| 1347 | # ifdef NCR5380_STAT_LIMIT |
| 1348 | if (cmd->request_bufflen > NCR5380_STAT_LIMIT) |
| 1349 | # endif |
| 1350 | switch (cmd->cmnd[0]) |
| 1351 | { |
| 1352 | case WRITE: |
| 1353 | case WRITE_6: |
| 1354 | case WRITE_10: |
| 1355 | hostdata->time_write[cmd->device->id] += (jiffies - hostdata->timebase); |
| 1356 | /*hostdata->bytes_write[cmd->device->id] += cmd->request_bufflen;*/ |
| 1357 | hostdata->pendingw--; |
| 1358 | break; |
| 1359 | case READ: |
| 1360 | case READ_6: |
| 1361 | case READ_10: |
| 1362 | hostdata->time_read[cmd->device->id] += (jiffies - hostdata->timebase); |
| 1363 | /*hostdata->bytes_read[cmd->device->id] += cmd->request_bufflen;*/ |
| 1364 | hostdata->pendingr--; |
| 1365 | break; |
| 1366 | } |
| 1367 | } |
| 1368 | #endif |
| 1369 | |
| 1370 | /* |
| 1371 | * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd, |
| 1372 | * int tag); |
| 1373 | * |
| 1374 | * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command, |
| 1375 | * including ARBITRATION, SELECTION, and initial message out for |
| 1376 | * IDENTIFY and queue messages. |
| 1377 | * |
| 1378 | * Inputs : instance - instantiation of the 5380 driver on which this |
| 1379 | * target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for |
| 1380 | * new tag, TAG_NONE for untagged queueing, otherwise set to the tag for |
| 1381 | * the command that is presently connected. |
| 1382 | * |
| 1383 | * Returns : -1 if selection could not execute for some reason, |
| 1384 | * 0 if selection succeeded or failed because the target |
| 1385 | * did not respond. |
| 1386 | * |
| 1387 | * Side effects : |
| 1388 | * If bus busy, arbitration failed, etc, NCR5380_select() will exit |
| 1389 | * with registers as they should have been on entry - ie |
| 1390 | * SELECT_ENABLE will be set appropriately, the NCR5380 |
| 1391 | * will cease to drive any SCSI bus signals. |
| 1392 | * |
| 1393 | * If successful : I_T_L or I_T_L_Q nexus will be established, |
| 1394 | * instance->connected will be set to cmd. |
| 1395 | * SELECT interrupt will be disabled. |
| 1396 | * |
| 1397 | * If failed (no target) : cmd->scsi_done() will be called, and the |
| 1398 | * cmd->result host byte set to DID_BAD_TARGET. |
| 1399 | */ |
| 1400 | |
| 1401 | static int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd, int tag) |
| 1402 | { |
| 1403 | SETUP_HOSTDATA(instance); |
| 1404 | unsigned char tmp[3], phase; |
| 1405 | unsigned char *data; |
| 1406 | int len; |
| 1407 | unsigned long timeout; |
| 1408 | unsigned long flags; |
| 1409 | |
| 1410 | hostdata->restart_select = 0; |
| 1411 | NCR_PRINT(NDEBUG_ARBITRATION); |
| 1412 | ARB_PRINTK("scsi%d: starting arbitration, id = %d\n", HOSTNO, |
| 1413 | instance->this_id); |
| 1414 | |
| 1415 | /* |
| 1416 | * Set the phase bits to 0, otherwise the NCR5380 won't drive the |
| 1417 | * data bus during SELECTION. |
| 1418 | */ |
| 1419 | |
| 1420 | local_irq_save(flags); |
| 1421 | if (hostdata->connected) { |
| 1422 | local_irq_restore(flags); |
| 1423 | return -1; |
| 1424 | } |
| 1425 | NCR5380_write(TARGET_COMMAND_REG, 0); |
| 1426 | |
| 1427 | |
| 1428 | /* |
| 1429 | * Start arbitration. |
| 1430 | */ |
| 1431 | |
| 1432 | NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask); |
| 1433 | NCR5380_write(MODE_REG, MR_ARBITRATE); |
| 1434 | |
| 1435 | local_irq_restore(flags); |
| 1436 | |
| 1437 | /* Wait for arbitration logic to complete */ |
| 1438 | #if NCR_TIMEOUT |
| 1439 | { |
| 1440 | unsigned long timeout = jiffies + 2*NCR_TIMEOUT; |
| 1441 | |
| 1442 | while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) |
| 1443 | && time_before(jiffies, timeout) && !hostdata->connected) |
| 1444 | ; |
| 1445 | if (time_after_eq(jiffies, timeout)) |
| 1446 | { |
| 1447 | printk("scsi : arbitration timeout at %d\n", __LINE__); |
| 1448 | NCR5380_write(MODE_REG, MR_BASE); |
| 1449 | NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask); |
| 1450 | return -1; |
| 1451 | } |
| 1452 | } |
| 1453 | #else /* NCR_TIMEOUT */ |
| 1454 | while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) |
| 1455 | && !hostdata->connected); |
| 1456 | #endif |
| 1457 | |
| 1458 | ARB_PRINTK("scsi%d: arbitration complete\n", HOSTNO); |
| 1459 | |
| 1460 | if (hostdata->connected) { |
| 1461 | NCR5380_write(MODE_REG, MR_BASE); |
| 1462 | return -1; |
| 1463 | } |
| 1464 | /* |
| 1465 | * The arbitration delay is 2.2us, but this is a minimum and there is |
| 1466 | * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate |
| 1467 | * the integral nature of udelay(). |
| 1468 | * |
| 1469 | */ |
| 1470 | |
| 1471 | udelay(3); |
| 1472 | |
| 1473 | /* Check for lost arbitration */ |
| 1474 | if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) || |
| 1475 | (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) || |
| 1476 | (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) || |
| 1477 | hostdata->connected) { |
| 1478 | NCR5380_write(MODE_REG, MR_BASE); |
| 1479 | ARB_PRINTK("scsi%d: lost arbitration, deasserting MR_ARBITRATE\n", |
| 1480 | HOSTNO); |
| 1481 | return -1; |
| 1482 | } |
| 1483 | |
| 1484 | /* after/during arbitration, BSY should be asserted. |
| 1485 | IBM DPES-31080 Version S31Q works now */ |
| 1486 | /* Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman) */ |
| 1487 | NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_SEL | |
| 1488 | ICR_ASSERT_BSY ) ; |
| 1489 | |
| 1490 | if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) || |
| 1491 | hostdata->connected) { |
| 1492 | NCR5380_write(MODE_REG, MR_BASE); |
| 1493 | NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); |
| 1494 | ARB_PRINTK("scsi%d: lost arbitration, deasserting ICR_ASSERT_SEL\n", |
| 1495 | HOSTNO); |
| 1496 | return -1; |
| 1497 | } |
| 1498 | |
| 1499 | /* |
| 1500 | * Again, bus clear + bus settle time is 1.2us, however, this is |
| 1501 | * a minimum so we'll udelay ceil(1.2) |
| 1502 | */ |
| 1503 | |
| 1504 | #ifdef CONFIG_ATARI_SCSI_TOSHIBA_DELAY |
| 1505 | /* ++roman: But some targets (see above :-) seem to need a bit more... */ |
| 1506 | udelay(15); |
| 1507 | #else |
| 1508 | udelay(2); |
| 1509 | #endif |
| 1510 | |
| 1511 | if (hostdata->connected) { |
| 1512 | NCR5380_write(MODE_REG, MR_BASE); |
| 1513 | NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); |
| 1514 | return -1; |
| 1515 | } |
| 1516 | |
| 1517 | ARB_PRINTK("scsi%d: won arbitration\n", HOSTNO); |
| 1518 | |
| 1519 | /* |
| 1520 | * Now that we have won arbitration, start Selection process, asserting |
| 1521 | * the host and target ID's on the SCSI bus. |
| 1522 | */ |
| 1523 | |
| 1524 | NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << cmd->device->id))); |
| 1525 | |
| 1526 | /* |
| 1527 | * Raise ATN while SEL is true before BSY goes false from arbitration, |
| 1528 | * since this is the only way to guarantee that we'll get a MESSAGE OUT |
| 1529 | * phase immediately after selection. |
| 1530 | */ |
| 1531 | |
| 1532 | NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY | |
| 1533 | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL )); |
| 1534 | NCR5380_write(MODE_REG, MR_BASE); |
| 1535 | |
| 1536 | /* |
| 1537 | * Reselect interrupts must be turned off prior to the dropping of BSY, |
| 1538 | * otherwise we will trigger an interrupt. |
| 1539 | */ |
| 1540 | |
| 1541 | if (hostdata->connected) { |
| 1542 | NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); |
| 1543 | return -1; |
| 1544 | } |
| 1545 | |
| 1546 | NCR5380_write(SELECT_ENABLE_REG, 0); |
| 1547 | |
| 1548 | /* |
| 1549 | * The initiator shall then wait at least two deskew delays and release |
| 1550 | * the BSY signal. |
| 1551 | */ |
| 1552 | udelay(1); /* wingel -- wait two bus deskew delay >2*45ns */ |
| 1553 | |
| 1554 | /* Reset BSY */ |
| 1555 | NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA | |
| 1556 | ICR_ASSERT_ATN | ICR_ASSERT_SEL)); |
| 1557 | |
| 1558 | /* |
| 1559 | * Something weird happens when we cease to drive BSY - looks |
| 1560 | * like the board/chip is letting us do another read before the |
| 1561 | * appropriate propagation delay has expired, and we're confusing |
| 1562 | * a BSY signal from ourselves as the target's response to SELECTION. |
| 1563 | * |
| 1564 | * A small delay (the 'C++' frontend breaks the pipeline with an |
| 1565 | * unnecessary jump, making it work on my 386-33/Trantor T128, the |
| 1566 | * tighter 'C' code breaks and requires this) solves the problem - |
| 1567 | * the 1 us delay is arbitrary, and only used because this delay will |
| 1568 | * be the same on other platforms and since it works here, it should |
| 1569 | * work there. |
| 1570 | * |
| 1571 | * wingel suggests that this could be due to failing to wait |
| 1572 | * one deskew delay. |
| 1573 | */ |
| 1574 | |
| 1575 | udelay(1); |
| 1576 | |
| 1577 | SEL_PRINTK("scsi%d: selecting target %d\n", HOSTNO, cmd->device->id); |
| 1578 | |
| 1579 | /* |
| 1580 | * The SCSI specification calls for a 250 ms timeout for the actual |
| 1581 | * selection. |
| 1582 | */ |
| 1583 | |
| 1584 | timeout = jiffies + 25; |
| 1585 | |
| 1586 | /* |
| 1587 | * XXX very interesting - we're seeing a bounce where the BSY we |
| 1588 | * asserted is being reflected / still asserted (propagation delay?) |
| 1589 | * and it's detecting as true. Sigh. |
| 1590 | */ |
| 1591 | |
| 1592 | #if 0 |
| 1593 | /* ++roman: If a target conformed to the SCSI standard, it wouldn't assert |
| 1594 | * IO while SEL is true. But again, there are some disks out the in the |
| 1595 | * world that do that nevertheless. (Somebody claimed that this announces |
| 1596 | * reselection capability of the target.) So we better skip that test and |
| 1597 |