899 lines · c
1/*2 * atari_scsi.c -- Device dependent functions for the Atari generic SCSI port3 *4 * Copyright 1994 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>5 *6 * Loosely based on the work of Robert De Vries' team and added:7 * - working real DMA8 * - Falcon support (untested yet!) ++bjoern fixed and now it works9 * - lots of extensions and bug fixes.10 *11 * This file is subject to the terms and conditions of the GNU General Public12 * License. See the file COPYING in the main directory of this archive13 * for more details.14 *15 */16 17/*18 * Notes for Falcon SCSI DMA19 *20 * The 5380 device is one of several that all share the DMA chip. Hence21 * "locking" and "unlocking" access to this chip is required.22 *23 * Two possible schemes for ST DMA acquisition by atari_scsi are:24 * 1) The lock is taken for each command separately (i.e. can_queue == 1).25 * 2) The lock is taken when the first command arrives and released26 * when the last command is finished (i.e. can_queue > 1).27 *28 * The first alternative limits SCSI bus utilization, since interleaving29 * commands is not possible. The second gives better performance but is30 * unfair to other drivers needing to use the ST DMA chip. In order to31 * allow the IDE and floppy drivers equal access to the ST DMA chip32 * the default is can_queue == 1.33 */34 35#include <linux/module.h>36#include <linux/types.h>37#include <linux/blkdev.h>38#include <linux/interrupt.h>39#include <linux/init.h>40#include <linux/nvram.h>41#include <linux/bitops.h>42#include <linux/wait.h>43#include <linux/platform_device.h>44 45#include <asm/setup.h>46#include <asm/atarihw.h>47#include <asm/atariints.h>48#include <asm/atari_stdma.h>49#include <asm/atari_stram.h>50#include <asm/io.h>51 52#include <scsi/scsi_host.h>53 54#define DMA_MIN_SIZE 3255 56/* Definitions for the core NCR5380 driver. */57 58#define NCR5380_implementation_fields /* none */59 60static u8 (*atari_scsi_reg_read)(unsigned int);61static void (*atari_scsi_reg_write)(unsigned int, u8);62 63#define NCR5380_read(reg) atari_scsi_reg_read(reg)64#define NCR5380_write(reg, value) atari_scsi_reg_write(reg, value)65 66#define NCR5380_queue_command atari_scsi_queue_command67#define NCR5380_abort atari_scsi_abort68#define NCR5380_info atari_scsi_info69 70#define NCR5380_dma_xfer_len atari_scsi_dma_xfer_len71#define NCR5380_dma_recv_setup atari_scsi_dma_recv_setup72#define NCR5380_dma_send_setup atari_scsi_dma_send_setup73#define NCR5380_dma_residual atari_scsi_dma_residual74 75#define NCR5380_acquire_dma_irq(instance) falcon_get_lock(instance)76#define NCR5380_release_dma_irq(instance) falcon_release_lock()77 78#include "NCR5380.h"79 80 81#define IS_A_TT() ATARIHW_PRESENT(TT_SCSI)82 83#define SCSI_DMA_WRITE_P(elt,val) \84 do { \85 unsigned long v = val; \86 tt_scsi_dma.elt##_lo = v & 0xff; \87 v >>= 8; \88 tt_scsi_dma.elt##_lmd = v & 0xff; \89 v >>= 8; \90 tt_scsi_dma.elt##_hmd = v & 0xff; \91 v >>= 8; \92 tt_scsi_dma.elt##_hi = v & 0xff; \93 } while(0)94 95#define SCSI_DMA_READ_P(elt) \96 (((((((unsigned long)tt_scsi_dma.elt##_hi << 8) | \97 (unsigned long)tt_scsi_dma.elt##_hmd) << 8) | \98 (unsigned long)tt_scsi_dma.elt##_lmd) << 8) | \99 (unsigned long)tt_scsi_dma.elt##_lo)100 101 102static inline void SCSI_DMA_SETADR(unsigned long adr)103{104 st_dma.dma_lo = (unsigned char)adr;105 MFPDELAY();106 adr >>= 8;107 st_dma.dma_md = (unsigned char)adr;108 MFPDELAY();109 adr >>= 8;110 st_dma.dma_hi = (unsigned char)adr;111 MFPDELAY();112}113 114static inline unsigned long SCSI_DMA_GETADR(void)115{116 unsigned long adr;117 adr = st_dma.dma_lo;118 MFPDELAY();119 adr |= (st_dma.dma_md & 0xff) << 8;120 MFPDELAY();121 adr |= (st_dma.dma_hi & 0xff) << 16;122 MFPDELAY();123 return adr;124}125 126static void atari_scsi_fetch_restbytes(void);127 128static unsigned long atari_dma_residual, atari_dma_startaddr;129static short atari_dma_active;130/* pointer to the dribble buffer */131static char *atari_dma_buffer;132/* precalculated physical address of the dribble buffer */133static unsigned long atari_dma_phys_buffer;134/* != 0 tells the Falcon int handler to copy data from the dribble buffer */135static char *atari_dma_orig_addr;136/* size of the dribble buffer; 4k seems enough, since the Falcon cannot use137 * scatter-gather anyway, so most transfers are 1024 byte only. In the rare138 * cases where requests to physical contiguous buffers have been merged, this139 * request is <= 4k (one page). So I don't think we have to split transfers140 * just due to this buffer size...141 */142#define STRAM_BUFFER_SIZE (4096)143/* mask for address bits that can't be used with the ST-DMA */144static unsigned long atari_dma_stram_mask;145#define STRAM_ADDR(a) (((a) & atari_dma_stram_mask) == 0)146 147static int setup_can_queue = -1;148module_param(setup_can_queue, int, 0);149static int setup_cmd_per_lun = -1;150module_param(setup_cmd_per_lun, int, 0);151static int setup_sg_tablesize = -1;152module_param(setup_sg_tablesize, int, 0);153static int setup_hostid = -1;154module_param(setup_hostid, int, 0);155static int setup_toshiba_delay = -1;156module_param(setup_toshiba_delay, int, 0);157 158 159static int scsi_dma_is_ignored_buserr(unsigned char dma_stat)160{161 int i;162 unsigned long addr = SCSI_DMA_READ_P(dma_addr), end_addr;163 164 if (dma_stat & 0x01) {165 166 /* A bus error happens when DMA-ing from the last page of a167 * physical memory chunk (DMA prefetch!), but that doesn't hurt.168 * Check for this case:169 */170 171 for (i = 0; i < m68k_num_memory; ++i) {172 end_addr = m68k_memory[i].addr + m68k_memory[i].size;173 if (end_addr <= addr && addr <= end_addr + 4)174 return 1;175 }176 }177 return 0;178}179 180 181static irqreturn_t scsi_tt_intr(int irq, void *dev)182{183 struct Scsi_Host *instance = dev;184 struct NCR5380_hostdata *hostdata = shost_priv(instance);185 int dma_stat;186 187 dma_stat = tt_scsi_dma.dma_ctrl;188 189 dsprintk(NDEBUG_INTR, instance, "NCR5380 interrupt, DMA status = %02x\n",190 dma_stat & 0xff);191 192 /* Look if it was the DMA that has interrupted: First possibility193 * is that a bus error occurred...194 */195 if (dma_stat & 0x80) {196 if (!scsi_dma_is_ignored_buserr(dma_stat)) {197 printk(KERN_ERR "SCSI DMA caused bus error near 0x%08lx\n",198 SCSI_DMA_READ_P(dma_addr));199 printk(KERN_CRIT "SCSI DMA bus error -- bad DMA programming!");200 }201 }202 203 /* If the DMA is active but not finished, we have the case204 * that some other 5380 interrupt occurred within the DMA transfer.205 * This means we have residual bytes, if the desired end address206 * is not yet reached. Maybe we have to fetch some bytes from the207 * rest data register, too. The residual must be calculated from208 * the address pointer, not the counter register, because only the209 * addr reg counts bytes not yet written and pending in the rest210 * data reg!211 */212 if ((dma_stat & 0x02) && !(dma_stat & 0x40)) {213 atari_dma_residual = hostdata->dma_len -214 (SCSI_DMA_READ_P(dma_addr) - atari_dma_startaddr);215 216 dprintk(NDEBUG_DMA, "SCSI DMA: There are %ld residual bytes.\n",217 atari_dma_residual);218 219 if ((signed int)atari_dma_residual < 0)220 atari_dma_residual = 0;221 if ((dma_stat & 1) == 0) {222 /*223 * After read operations, we maybe have to224 * transport some rest bytes225 */226 atari_scsi_fetch_restbytes();227 } else {228 /*229 * There seems to be a nasty bug in some SCSI-DMA/NCR230 * combinations: If a target disconnects while a write231 * operation is going on, the address register of the232 * DMA may be a few bytes farer than it actually read.233 * This is probably due to DMA prefetching and a delay234 * between DMA and NCR. Experiments showed that the235 * dma_addr is 9 bytes to high, but this could vary.236 * The problem is, that the residual is thus calculated237 * wrong and the next transfer will start behind where238 * it should. So we round up the residual to the next239 * multiple of a sector size, if it isn't already a240 * multiple and the originally expected transfer size241 * was. The latter condition is there to ensure that242 * the correction is taken only for "real" data243 * transfers and not for, e.g., the parameters of some244 * other command. These shouldn't disconnect anyway.245 */246 if (atari_dma_residual & 0x1ff) {247 dprintk(NDEBUG_DMA, "SCSI DMA: DMA bug corrected, "248 "difference %ld bytes\n",249 512 - (atari_dma_residual & 0x1ff));250 atari_dma_residual = (atari_dma_residual + 511) & ~0x1ff;251 }252 }253 tt_scsi_dma.dma_ctrl = 0;254 }255 256 /* If the DMA is finished, fetch the rest bytes and turn it off */257 if (dma_stat & 0x40) {258 atari_dma_residual = 0;259 if ((dma_stat & 1) == 0)260 atari_scsi_fetch_restbytes();261 tt_scsi_dma.dma_ctrl = 0;262 }263 264 NCR5380_intr(irq, dev);265 266 return IRQ_HANDLED;267}268 269 270static irqreturn_t scsi_falcon_intr(int irq, void *dev)271{272 struct Scsi_Host *instance = dev;273 struct NCR5380_hostdata *hostdata = shost_priv(instance);274 int dma_stat;275 276 /* Turn off DMA and select sector counter register before277 * accessing the status register (Atari recommendation!)278 */279 st_dma.dma_mode_status = 0x90;280 dma_stat = st_dma.dma_mode_status;281 282 /* Bit 0 indicates some error in the DMA process... don't know283 * what happened exactly (no further docu).284 */285 if (!(dma_stat & 0x01)) {286 /* DMA error */287 printk(KERN_CRIT "SCSI DMA error near 0x%08lx!\n", SCSI_DMA_GETADR());288 }289 290 /* If the DMA was active, but now bit 1 is not clear, it is some291 * other 5380 interrupt that finishes the DMA transfer. We have to292 * calculate the number of residual bytes and give a warning if293 * bytes are stuck in the ST-DMA fifo (there's no way to reach them!)294 */295 if (atari_dma_active && (dma_stat & 0x02)) {296 unsigned long transferred;297 298 transferred = SCSI_DMA_GETADR() - atari_dma_startaddr;299 /* The ST-DMA address is incremented in 2-byte steps, but the300 * data are written only in 16-byte chunks. If the number of301 * transferred bytes is not divisible by 16, the remainder is302 * lost somewhere in outer space.303 */304 if (transferred & 15)305 printk(KERN_ERR "SCSI DMA error: %ld bytes lost in "306 "ST-DMA fifo\n", transferred & 15);307 308 atari_dma_residual = hostdata->dma_len - transferred;309 dprintk(NDEBUG_DMA, "SCSI DMA: There are %ld residual bytes.\n",310 atari_dma_residual);311 } else312 atari_dma_residual = 0;313 atari_dma_active = 0;314 315 if (atari_dma_orig_addr) {316 /* If the dribble buffer was used on a read operation, copy the DMA-ed317 * data to the original destination address.318 */319 memcpy(atari_dma_orig_addr, phys_to_virt(atari_dma_startaddr),320 hostdata->dma_len - atari_dma_residual);321 atari_dma_orig_addr = NULL;322 }323 324 NCR5380_intr(irq, dev);325 326 return IRQ_HANDLED;327}328 329 330static void atari_scsi_fetch_restbytes(void)331{332 int nr;333 char *src, *dst;334 unsigned long phys_dst;335 336 /* fetch rest bytes in the DMA register */337 phys_dst = SCSI_DMA_READ_P(dma_addr);338 nr = phys_dst & 3;339 if (nr) {340 /* there are 'nr' bytes left for the last long address341 before the DMA pointer */342 phys_dst ^= nr;343 dprintk(NDEBUG_DMA, "SCSI DMA: there are %d rest bytes for phys addr 0x%08lx",344 nr, phys_dst);345 /* The content of the DMA pointer is a physical address! */346 dst = phys_to_virt(phys_dst);347 dprintk(NDEBUG_DMA, " = virt addr %p\n", dst);348 for (src = (char *)&tt_scsi_dma.dma_restdata; nr != 0; --nr)349 *dst++ = *src++;350 }351}352 353 354/* This function releases the lock on the DMA chip if there is no355 * connected command and the disconnected queue is empty.356 */357 358static void falcon_release_lock(void)359{360 if (IS_A_TT())361 return;362 363 if (stdma_is_locked_by(scsi_falcon_intr))364 stdma_release();365}366 367/* This function manages the locking of the ST-DMA.368 * If the DMA isn't locked already for SCSI, it tries to lock it by369 * calling stdma_lock(). But if the DMA is locked by the SCSI code and370 * there are other drivers waiting for the chip, we do not issue the371 * command immediately but tell the SCSI mid-layer to defer.372 */373 374static int falcon_get_lock(struct Scsi_Host *instance)375{376 if (IS_A_TT())377 return 1;378 379 if (stdma_is_locked_by(scsi_falcon_intr))380 return 1;381 382 /* stdma_lock() may sleep which means it can't be used here */383 return stdma_try_lock(scsi_falcon_intr, instance);384}385 386#ifndef MODULE387static int __init atari_scsi_setup(char *str)388{389 /* Format of atascsi parameter is:390 * atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>391 * Defaults depend on TT or Falcon, determined at run time.392 * Negative values mean don't change.393 */394 int ints[8];395 396 get_options(str, ARRAY_SIZE(ints), ints);397 398 if (ints[0] < 1) {399 printk("atari_scsi_setup: no arguments!\n");400 return 0;401 }402 if (ints[0] >= 1)403 setup_can_queue = ints[1];404 if (ints[0] >= 2)405 setup_cmd_per_lun = ints[2];406 if (ints[0] >= 3)407 setup_sg_tablesize = ints[3];408 if (ints[0] >= 4)409 setup_hostid = ints[4];410 /* ints[5] (use_tagged_queuing) is ignored */411 /* ints[6] (use_pdma) is ignored */412 if (ints[0] >= 7)413 setup_toshiba_delay = ints[7];414 415 return 1;416}417 418__setup("atascsi=", atari_scsi_setup);419#endif /* !MODULE */420 421static unsigned long atari_scsi_dma_setup(struct NCR5380_hostdata *hostdata,422 void *data, unsigned long count,423 int dir)424{425 unsigned long addr = virt_to_phys(data);426 427 dprintk(NDEBUG_DMA, "scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, dir = %d\n",428 hostdata->host->host_no, data, addr, count, dir);429 430 if (!IS_A_TT() && !STRAM_ADDR(addr)) {431 /* If we have a non-DMAable address on a Falcon, use the dribble432 * buffer; 'orig_addr' != 0 in the read case tells the interrupt433 * handler to copy data from the dribble buffer to the originally434 * wanted address.435 */436 if (dir)437 memcpy(atari_dma_buffer, data, count);438 else439 atari_dma_orig_addr = data;440 addr = atari_dma_phys_buffer;441 }442 443 atari_dma_startaddr = addr; /* Needed for calculating residual later. */444 445 /* Cache cleanup stuff: On writes, push any dirty cache out before sending446 * it to the peripheral. (Must be done before DMA setup, since at least447 * the ST-DMA begins to fill internal buffers right after setup. For448 * reads, invalidate any cache, may be altered after DMA without CPU449 * knowledge.450 *451 * ++roman: For the Medusa, there's no need at all for that cache stuff,452 * because the hardware does bus snooping (fine!).453 */454 dma_cache_maintenance(addr, count, dir);455 456 if (IS_A_TT()) {457 tt_scsi_dma.dma_ctrl = dir;458 SCSI_DMA_WRITE_P(dma_addr, addr);459 SCSI_DMA_WRITE_P(dma_cnt, count);460 tt_scsi_dma.dma_ctrl = dir | 2;461 } else { /* ! IS_A_TT */462 463 /* set address */464 SCSI_DMA_SETADR(addr);465 466 /* toggle direction bit to clear FIFO and set DMA direction */467 dir <<= 8;468 st_dma.dma_mode_status = 0x90 | dir;469 st_dma.dma_mode_status = 0x90 | (dir ^ 0x100);470 st_dma.dma_mode_status = 0x90 | dir;471 udelay(40);472 /* On writes, round up the transfer length to the next multiple of 512473 * (see also comment at atari_dma_xfer_len()). */474 st_dma.fdc_acces_seccount = (count + (dir ? 511 : 0)) >> 9;475 udelay(40);476 st_dma.dma_mode_status = 0x10 | dir;477 udelay(40);478 /* need not restore value of dir, only boolean value is tested */479 atari_dma_active = 1;480 }481 482 return count;483}484 485static inline int atari_scsi_dma_recv_setup(struct NCR5380_hostdata *hostdata,486 unsigned char *data, int count)487{488 return atari_scsi_dma_setup(hostdata, data, count, 0);489}490 491static inline int atari_scsi_dma_send_setup(struct NCR5380_hostdata *hostdata,492 unsigned char *data, int count)493{494 return atari_scsi_dma_setup(hostdata, data, count, 1);495}496 497static int atari_scsi_dma_residual(struct NCR5380_hostdata *hostdata)498{499 return atari_dma_residual;500}501 502 503#define CMD_SURELY_BLOCK_MODE 0504#define CMD_SURELY_BYTE_MODE 1505#define CMD_MODE_UNKNOWN 2506 507static int falcon_classify_cmd(struct scsi_cmnd *cmd)508{509 unsigned char opcode = cmd->cmnd[0];510 511 if (opcode == READ_DEFECT_DATA || opcode == READ_LONG ||512 opcode == READ_BUFFER)513 return CMD_SURELY_BYTE_MODE;514 else if (opcode == READ_6 || opcode == READ_10 ||515 opcode == 0xa8 /* READ_12 */ || opcode == READ_REVERSE ||516 opcode == RECOVER_BUFFERED_DATA) {517 /* In case of a sequential-access target (tape), special care is518 * needed here: The transfer is block-mode only if the 'fixed' bit is519 * set! */520 if (cmd->device->type == TYPE_TAPE && !(cmd->cmnd[1] & 1))521 return CMD_SURELY_BYTE_MODE;522 else523 return CMD_SURELY_BLOCK_MODE;524 } else525 return CMD_MODE_UNKNOWN;526}527 528 529/* This function calculates the number of bytes that can be transferred via530 * DMA. On the TT, this is arbitrary, but on the Falcon we have to use the531 * ST-DMA chip. There are only multiples of 512 bytes possible and max.532 * 255*512 bytes :-( This means also, that defining READ_OVERRUNS is not533 * possible on the Falcon, since that would require to program the DMA for534 * n*512 - atari_read_overrun bytes. But it seems that the Falcon doesn't have535 * the overrun problem, so this question is academic :-)536 */537 538static int atari_scsi_dma_xfer_len(struct NCR5380_hostdata *hostdata,539 struct scsi_cmnd *cmd)540{541 int wanted_len = NCR5380_to_ncmd(cmd)->this_residual;542 int possible_len, limit;543 544 if (wanted_len < DMA_MIN_SIZE)545 return 0;546 547 if (IS_A_TT())548 /* TT SCSI DMA can transfer arbitrary #bytes */549 return wanted_len;550 551 /* ST DMA chip is stupid -- only multiples of 512 bytes! (and max.552 * 255*512 bytes, but this should be enough)553 *554 * ++roman: Aaargl! Another Falcon-SCSI problem... There are some commands555 * that return a number of bytes which cannot be known beforehand. In this556 * case, the given transfer length is an "allocation length". Now it557 * can happen that this allocation length is a multiple of 512 bytes and558 * the DMA is used. But if not n*512 bytes really arrive, some input data559 * will be lost in the ST-DMA's FIFO :-( Thus, we have to distinguish560 * between commands that do block transfers and those that do byte561 * transfers. But this isn't easy... there are lots of vendor specific562 * commands, and the user can issue any command via the563 * SCSI_IOCTL_SEND_COMMAND.564 *565 * The solution: We classify SCSI commands in 1) surely block-mode cmd.s,566 * 2) surely byte-mode cmd.s and 3) cmd.s with unknown mode. In case 1)567 * and 3), the thing to do is obvious: allow any number of blocks via DMA568 * or none. In case 2), we apply some heuristic: Byte mode is assumed if569 * the transfer (allocation) length is < 1024, hoping that no cmd. not570 * explicitly known as byte mode have such big allocation lengths...571 * BTW, all the discussion above applies only to reads. DMA writes are572 * unproblematic anyways, since the targets aborts the transfer after573 * receiving a sufficient number of bytes.574 *575 * Another point: If the transfer is from/to an non-ST-RAM address, we576 * use the dribble buffer and thus can do only STRAM_BUFFER_SIZE bytes.577 */578 579 if (cmd->sc_data_direction == DMA_TO_DEVICE) {580 /* Write operation can always use the DMA, but the transfer size must581 * be rounded up to the next multiple of 512 (atari_dma_setup() does582 * this).583 */584 possible_len = wanted_len;585 } else {586 /* Read operations: if the wanted transfer length is not a multiple of587 * 512, we cannot use DMA, since the ST-DMA cannot split transfers588 * (no interrupt on DMA finished!)589 */590 if (wanted_len & 0x1ff)591 possible_len = 0;592 else {593 /* Now classify the command (see above) and decide whether it is594 * allowed to do DMA at all */595 switch (falcon_classify_cmd(cmd)) {596 case CMD_SURELY_BLOCK_MODE:597 possible_len = wanted_len;598 break;599 case CMD_SURELY_BYTE_MODE:600 possible_len = 0; /* DMA prohibited */601 break;602 case CMD_MODE_UNKNOWN:603 default:604 /* For unknown commands assume block transfers if the transfer605 * size/allocation length is >= 1024 */606 possible_len = (wanted_len < 1024) ? 0 : wanted_len;607 break;608 }609 }610 }611 612 /* Last step: apply the hard limit on DMA transfers */613 limit = (atari_dma_buffer && !STRAM_ADDR(virt_to_phys(NCR5380_to_ncmd(cmd)->ptr))) ?614 STRAM_BUFFER_SIZE : 255*512;615 if (possible_len > limit)616 possible_len = limit;617 618 if (possible_len != wanted_len)619 dprintk(NDEBUG_DMA, "DMA transfer now %d bytes instead of %d\n",620 possible_len, wanted_len);621 622 return possible_len;623}624 625 626/* NCR5380 register access functions627 *628 * There are separate functions for TT and Falcon, because the access629 * methods are quite different. The calling macros NCR5380_read and630 * NCR5380_write call these functions via function pointers.631 */632 633static u8 atari_scsi_tt_reg_read(unsigned int reg)634{635 return tt_scsi_regp[reg * 2];636}637 638static void atari_scsi_tt_reg_write(unsigned int reg, u8 value)639{640 tt_scsi_regp[reg * 2] = value;641}642 643static u8 atari_scsi_falcon_reg_read(unsigned int reg)644{645 unsigned long flags;646 u8 result;647 648 reg += 0x88;649 local_irq_save(flags);650 dma_wd.dma_mode_status = (u_short)reg;651 result = (u8)dma_wd.fdc_acces_seccount;652 local_irq_restore(flags);653 return result;654}655 656static void atari_scsi_falcon_reg_write(unsigned int reg, u8 value)657{658 unsigned long flags;659 660 reg += 0x88;661 local_irq_save(flags);662 dma_wd.dma_mode_status = (u_short)reg;663 dma_wd.fdc_acces_seccount = (u_short)value;664 local_irq_restore(flags);665}666 667 668#include "NCR5380.c"669 670static int atari_scsi_host_reset(struct scsi_cmnd *cmd)671{672 int rv;673 unsigned long flags;674 675 local_irq_save(flags);676 677 /* Abort a maybe active DMA transfer */678 if (IS_A_TT()) {679 tt_scsi_dma.dma_ctrl = 0;680 } else {681 if (stdma_is_locked_by(scsi_falcon_intr))682 st_dma.dma_mode_status = 0x90;683 atari_dma_active = 0;684 atari_dma_orig_addr = NULL;685 }686 687 rv = NCR5380_host_reset(cmd);688 689 /* The 5380 raises its IRQ line while _RST is active but the ST DMA690 * "lock" has been released so this interrupt may end up handled by691 * floppy or IDE driver (if one of them holds the lock). The NCR5380692 * interrupt flag has been cleared already.693 */694 695 local_irq_restore(flags);696 697 return rv;698}699 700#define DRV_MODULE_NAME "atari_scsi"701#define PFX DRV_MODULE_NAME ": "702 703static struct scsi_host_template atari_scsi_template = {704 .module = THIS_MODULE,705 .proc_name = DRV_MODULE_NAME,706 .name = "Atari native SCSI",707 .info = atari_scsi_info,708 .queuecommand = atari_scsi_queue_command,709 .eh_abort_handler = atari_scsi_abort,710 .eh_host_reset_handler = atari_scsi_host_reset,711 .this_id = 7,712 .cmd_per_lun = 2,713 .dma_boundary = PAGE_SIZE - 1,714 .cmd_size = sizeof(struct NCR5380_cmd),715};716 717static int __init atari_scsi_probe(struct platform_device *pdev)718{719 struct Scsi_Host *instance;720 int error;721 struct resource *irq;722 int host_flags = 0;723 724 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);725 if (!irq)726 return -ENODEV;727 728 if (ATARIHW_PRESENT(TT_SCSI)) {729 atari_scsi_reg_read = atari_scsi_tt_reg_read;730 atari_scsi_reg_write = atari_scsi_tt_reg_write;731 } else {732 atari_scsi_reg_read = atari_scsi_falcon_reg_read;733 atari_scsi_reg_write = atari_scsi_falcon_reg_write;734 }735 736 if (ATARIHW_PRESENT(TT_SCSI)) {737 atari_scsi_template.can_queue = 16;738 atari_scsi_template.sg_tablesize = SG_ALL;739 } else {740 atari_scsi_template.can_queue = 1;741 atari_scsi_template.sg_tablesize = 1;742 }743 744 if (setup_can_queue > 0)745 atari_scsi_template.can_queue = setup_can_queue;746 747 if (setup_cmd_per_lun > 0)748 atari_scsi_template.cmd_per_lun = setup_cmd_per_lun;749 750 /* Don't increase sg_tablesize on Falcon! */751 if (ATARIHW_PRESENT(TT_SCSI) && setup_sg_tablesize > 0)752 atari_scsi_template.sg_tablesize = setup_sg_tablesize;753 754 if (setup_hostid >= 0) {755 atari_scsi_template.this_id = setup_hostid & 7;756 } else if (IS_REACHABLE(CONFIG_NVRAM)) {757 /* Test if a host id is set in the NVRam */758 if (ATARIHW_PRESENT(TT_CLK)) {759 unsigned char b;760 loff_t offset = 16;761 ssize_t count = nvram_read(&b, 1, &offset);762 763 /* Arbitration enabled? (for TOS)764 * If yes, use configured host ID765 */766 if ((count == 1) && (b & 0x80))767 atari_scsi_template.this_id = b & 7;768 }769 }770 771 /* If running on a Falcon and if there's TT-Ram (i.e., more than one772 * memory block, since there's always ST-Ram in a Falcon), then773 * allocate a STRAM_BUFFER_SIZE byte dribble buffer for transfers774 * from/to alternative Ram.775 */776 if (ATARIHW_PRESENT(ST_SCSI) && !ATARIHW_PRESENT(EXTD_DMA) &&777 m68k_realnum_memory > 1) {778 atari_dma_buffer = atari_stram_alloc(STRAM_BUFFER_SIZE, "SCSI");779 if (!atari_dma_buffer) {780 pr_err(PFX "can't allocate ST-RAM double buffer\n");781 return -ENOMEM;782 }783 atari_dma_phys_buffer = atari_stram_to_phys(atari_dma_buffer);784 atari_dma_orig_addr = NULL;785 }786 787 instance = scsi_host_alloc(&atari_scsi_template,788 sizeof(struct NCR5380_hostdata));789 if (!instance) {790 error = -ENOMEM;791 goto fail_alloc;792 }793 794 instance->irq = irq->start;795 796 host_flags |= IS_A_TT() ? 0 : FLAG_LATE_DMA_SETUP;797 host_flags |= setup_toshiba_delay > 0 ? FLAG_TOSHIBA_DELAY : 0;798 799 error = NCR5380_init(instance, host_flags);800 if (error)801 goto fail_init;802 803 if (IS_A_TT()) {804 error = request_irq(instance->irq, scsi_tt_intr, 0,805 "NCR5380", instance);806 if (error) {807 pr_err(PFX "request irq %d failed, aborting\n",808 instance->irq);809 goto fail_irq;810 }811 tt_mfp.active_edge |= 0x80; /* SCSI int on L->H */812 813 tt_scsi_dma.dma_ctrl = 0;814 atari_dma_residual = 0;815 816 /* While the read overruns (described by Drew Eckhardt in817 * NCR5380.c) never happened on TTs, they do in fact on the818 * Medusa (This was the cause why SCSI didn't work right for819 * so long there.) Since handling the overruns slows down820 * a bit, I turned the #ifdef's into a runtime condition.821 *822 * In principle it should be sufficient to do max. 1 byte with823 * PIO, but there is another problem on the Medusa with the DMA824 * rest data register. So read_overruns is currently set825 * to 4 to avoid having transfers that aren't a multiple of 4.826 * If the rest data bug is fixed, this can be lowered to 1.827 */828 if (MACH_IS_MEDUSA) {829 struct NCR5380_hostdata *hostdata =830 shost_priv(instance);831 832 hostdata->read_overruns = 4;833 }834 } else {835 /* Nothing to do for the interrupt: the ST-DMA is initialized836 * already.837 */838 atari_dma_residual = 0;839 atari_dma_active = 0;840 atari_dma_stram_mask = (ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000841 : 0xff000000);842 }843 844 NCR5380_maybe_reset_bus(instance);845 846 error = scsi_add_host(instance, NULL);847 if (error)848 goto fail_host;849 850 platform_set_drvdata(pdev, instance);851 852 scsi_scan_host(instance);853 return 0;854 855fail_host:856 if (IS_A_TT())857 free_irq(instance->irq, instance);858fail_irq:859 NCR5380_exit(instance);860fail_init:861 scsi_host_put(instance);862fail_alloc:863 if (atari_dma_buffer)864 atari_stram_free(atari_dma_buffer);865 return error;866}867 868static void __exit atari_scsi_remove(struct platform_device *pdev)869{870 struct Scsi_Host *instance = platform_get_drvdata(pdev);871 872 scsi_remove_host(instance);873 if (IS_A_TT())874 free_irq(instance->irq, instance);875 NCR5380_exit(instance);876 scsi_host_put(instance);877 if (atari_dma_buffer)878 atari_stram_free(atari_dma_buffer);879}880 881/*882 * atari_scsi_remove() lives in .exit.text. For drivers registered via883 * module_platform_driver_probe() this is ok because they cannot get unbound at884 * runtime. So mark the driver struct with __refdata to prevent modpost885 * triggering a section mismatch warning.886 */887static struct platform_driver atari_scsi_driver __refdata = {888 .remove_new = __exit_p(atari_scsi_remove),889 .driver = {890 .name = DRV_MODULE_NAME,891 },892};893 894module_platform_driver_probe(atari_scsi_driver, atari_scsi_probe);895 896MODULE_ALIAS("platform:" DRV_MODULE_NAME);897MODULE_DESCRIPTION("Atari TT/Falcon NCR5380 SCSI driver");898MODULE_LICENSE("GPL");899