/* * Drew Eckhardt's excellent 'Generic NCR5380' sources from Linux-PC * provided much of the inspiration and some of the code for this * driver. Everything I know about Amiga DMA was gleaned from careful * reading of Hamish Mcdonald's original wd33c93 driver; in fact, I * borrowed shamelessly from all over that source. Thanks Hamish! * * _This_ driver is (I feel) an improvement over the old one in * several respects: * * - Target Disconnection/Reconnection is now supported. Any * system with more than one device active on the SCSI bus * will benefit from this. The driver defaults to what I * call 'adaptive disconnect' - meaning that each command * is evaluated individually as to whether or not it should * be run with the option to disconnect/reselect (if the * device chooses), or as a "SCSI-bus-hog". * * - Synchronous data transfers are now supported. Because of * a few devices that choke after telling the driver that * they can do sync transfers, we don't automatically use * this faster protocol - it can be enabled via the command- * line on a device-by-device basis. * * - Runtime operating parameters can now be specified through * the 'amiboot' or the 'insmod' command line. For amiboot do: * "amiboot [usual stuff] wd33c93=blah,blah,blah" * The defaults should be good for most people. See the comment * for 'setup_strings' below for more details. * * - The old driver relied exclusively on what the Western Digital * docs call "Combination Level 2 Commands", which are a great * idea in that the CPU is relieved of a lot of interrupt * overhead. However, by accepting a certain (user-settable) * amount of additional interrupts, this driver achieves * better control over the SCSI bus, and data transfers are * almost as fast while being much easier to define, track, * and debug. * * * TODO: * more speed. linked commands. * * * People with bug reports, wish-lists, complaints, comments, * or improvements are asked to pah-leeez email me (John Shifflett) * at john@geolog.com or jshiffle@netcom.com! I'm anxious to get * this thing into as good a shape as possible, and I'm positive * there are lots of lurking bugs and "Stupid Places". * * Updates: * * Added support for pre -A chips, which don't have advanced features * and will generate CSR_RESEL rather than CSR_RESEL_AM. * Richard Hirst <richard@sleepie.demon.co.uk> August 2000 * * Added support for Burst Mode DMA and Fast SCSI. Enabled the use of * default_sx_per for asynchronous data transfers. Added adjustment * of transfer periods in sx_table to the actual input-clock. * peter fuerst <post@pfrst.de> February 2007
*/
/* * 'setup_strings' is a single string used to pass operating parameters and * settings from the kernel/module command-line to the driver. 'setup_args[]' * is an array of strings that define the compile-time default values for * these settings. If Linux boots with an amiboot or insmod command-line, * those settings are combined with 'setup_args[]'. Note that amiboot * command-lines are prefixed with "wd33c93=" while insmod uses a * "setup_strings=" prefix. The driver recognizes the following keywords * (lower case required) and arguments: * * - nosync:bitmask -bitmask is a byte where the 1st 7 bits correspond with * the 7 possible SCSI devices. Set a bit to negotiate for * asynchronous transfers on that device. To maintain * backwards compatibility, a command-line such as * "wd33c93=255" will be automatically translated to * "wd33c93=nosync:0xff". * - nodma:x -x = 1 to disable DMA, x = 0 to enable it. Argument is * optional - if not present, same as "nodma:1". * - period:ns -ns is the minimum # of nanoseconds in a SCSI data transfer * period. Default is 500; acceptable values are 250 - 1000. * - disconnect:x -x = 0 to never allow disconnects, 2 to always allow them. * x = 1 does 'adaptive' disconnects, which is the default * and generally the best choice. * - debug:x -If 'DEBUGGING_ON' is defined, x is a bit mask that causes * various types of debug output to printed - see the DB_xxx * defines in wd33c93.h * - clock:x -x = clock input in MHz for WD33c93 chip. Normal values * would be from 8 through 20. Default is 8. * - burst:x -x = 1 to use Burst Mode (or Demand-Mode) DMA, x = 0 to use * Single Byte DMA, which is the default. Argument is * optional - if not present, same as "burst:1". * - fast:x -x = 1 to enable Fast SCSI, which is only effective with * input-clock divisor 4 (WD33C93_FS_16_20), x = 0 to disable * it, which is the default. Argument is optional - if not * present, same as "fast:1". * - next -No argument. Used to separate blocks of keywords when * there's more than one host adapter in the system. * * Syntax Notes: * - Numeric arguments can be decimal or the '0x' form of hex notation. There * _must_ be a colon between a keyword and its numeric argument, with no * spaces. * - Keywords are separated by commas, no spaces, in the standard kernel * command-line manner. * - A keyword in the 'nth' comma-separated command-line member will overwrite * the 'nth' element of setup_args[]. A blank command-line member (in * other words, a comma with no preceding keyword) will _not_ overwrite * the corresponding setup_args[] element. * - If a keyword is used more than once, the first one applies to the first * SCSI host found, the second to the second card, etc, unless the 'next' * keyword is used to change the order. * * Some amiboot examples (for insmod, use 'setup_strings' instead of 'wd33c93'): * - wd33c93=nosync:255 * - wd33c93=nodma * - wd33c93=nodma:1 * - wd33c93=disconnect:2,nosync:0x08,period:250 * - wd33c93=debug:0x1c
*/
/* * Calculate Synchronous Transfer Register value from SDTR code.
*/ static uchar
calc_sync_xfer(unsignedint period, unsignedint offset, unsignedint fast, conststruct sx_period *sx_table)
{ /* When doing Fast SCSI synchronous data transfers, the corresponding * value in 'sx_table' is two times the actually used transfer period.
*/
uchar result;
if (offset && fast) {
fast = STR_FSS;
period *= 2;
} else {
fast = 0;
}
period *= 4; /* convert SDTR code to ns */
result = sx_table[round_period(period,sx_table)].reg_value;
result |= (offset < OPTIMUM_SX_OFF) ? offset : OPTIMUM_SX_OFF;
result |= fast; return result;
}
/* * Calculate SDTR code bytes [3],[4] from period and offset.
*/ staticinlinevoid
calc_sync_msg(unsignedint period, unsignedint offset, unsignedint fast,
uchar msg[2])
{ /* 'period' is a "normal"-mode value, like the ones in 'sx_table'. The * actually used transfer period for Fast SCSI synchronous data * transfers is half that value.
*/
period /= 4; if (offset && fast)
period /= 2;
msg[0] = period;
msg[1] = offset;
}
/* Set up a few fields in the scsi_cmnd structure for our own use: * - host_scribble is the pointer to the next cmd in the input queue * - result is what you'd expect
*/
cmd->host_scribble = NULL;
cmd->result = 0;
/* We use the Scsi_Pointer structure that's included with each command * as a scratchpad (as it's intended to be used!). The handy thing about * the SCp.xxx fields is that they're always associated with a given * cmd, and are preserved across disconnect-reselect. This means we * can pretty much ignore SAVE_POINTERS and RESTORE_POINTERS messages * if we keep all the critical pointers and counters in SCp: * - SCp.ptr is the pointer into the RAM buffer * - SCp.this_residual is the size of that buffer * - SCp.buffer points to the current scatter-gather buffer * - SCp.buffers_residual tells us how many S.G. buffers there are * - SCp.have_data_in is not used * - SCp.sent_command is not used * - SCp.phase records this command's SRCID_ER bit setting
*/
/* WD docs state that at the conclusion of a "LEVEL2" command, the * status byte can be retrieved from the LUN register. Apparently, * this is the case only for *uninterrupted* LEVEL2 commands! If * there are any unexpected phases entered, even if they are 100% * legal (different devices may choose to do things differently), * the LEVEL2 command sequence is exited. This often occurs prior * to receiving the status byte, in which case the driver does a * status phase interrupt and gets the status byte on its own. * While such a command can then be "resumed" (ie restarted to * finish up as a LEVEL2 command), the LUN register will NOT be * a valid status byte at the command's conclusion, and we must * use the byte obtained during the earlier interrupt. Here, we * preset SCp.Status to an illegal value (0xff) so that when * this command finally completes, we can tell where the actual * status byte is stored.
*/
scsi_pointer->Status = ILLEGAL_STATUS_BYTE;
/* * Add the cmd to the end of 'input_Q'. Note that REQUEST SENSE * commands are added to the head of the queue so that the desired * sense data is not lost before REQUEST_SENSE executes.
*/
spin_lock_irq(&hostdata->lock);
if (!(hostdata->input_Q) || (cmd->cmnd[0] == REQUEST_SENSE)) {
cmd->host_scribble = (uchar *) hostdata->input_Q;
hostdata->input_Q = cmd;
} else { /* find the end of the queue */ for (tmp = (struct scsi_cmnd *) hostdata->input_Q;
tmp->host_scribble;
tmp = (struct scsi_cmnd *) tmp->host_scribble) ;
tmp->host_scribble = (uchar *) cmd;
}
/* We know that there's at least one command in 'input_Q' now. * Go see if any of them are runnable!
*/
wd33c93_execute(cmd->device->host);
DB(DB_QUEUE_COMMAND, printk(")Q "))
spin_unlock_irq(&hostdata->lock); return 0;
}
DEF_SCSI_QCMD(wd33c93_queuecommand)
/* * This routine attempts to start a scsi command. If the host_card is * already connected, we give up immediately. Otherwise, look through * the input_Q, using the first command we find that's intended * for a currently non-busy target/lun. * * wd33c93_execute() is always called with interrupts disabled or from * the wd33c93_intr itself, which means that a wd33c93 interrupt * cannot occur while we are in here.
*/ staticvoid
wd33c93_execute(struct Scsi_Host *instance)
{ struct scsi_pointer *scsi_pointer; struct WD33C93_hostdata *hostdata =
(struct WD33C93_hostdata *) instance->hostdata; const wd33c93_regs regs = hostdata->regs; struct scsi_cmnd *cmd, *prev;
/* Now we need to figure out whether or not this command is a good * candidate for disconnect/reselect. We guess to the best of our * ability, based on a set of hierarchical rules. When several * devices are operating simultaneously, disconnects are usually * an advantage. In a single device system, or if only 1 device * is being accessed, transfers usually go faster if disconnects * are not allowed: * * + Commands should NEVER disconnect if hostdata->disconnect = * DIS_NEVER (this holds for tape drives also), and ALWAYS * disconnect if hostdata->disconnect = DIS_ALWAYS. * + Tape drive commands should always be allowed to disconnect. * + Disconnect should be allowed if disconnected_Q isn't empty. * + Commands should NOT disconnect if input_Q is empty. * + Disconnect should be allowed if there are commands in input_Q * for a different target/lun. In this case, the other commands * should be made disconnect-able, if not already. * * I know, I know - this code would flunk me out of any * "C Programming 101" class ever offered. But it's easy * to change around and experiment with for now.
*/
scsi_pointer = WD33C93_scsi_pointer(cmd);
scsi_pointer->phase = 0; /* assume no disconnect */ if (hostdata->disconnect == DIS_NEVER) goto no; if (hostdata->disconnect == DIS_ALWAYS) goto yes; if (cmd->device->type == 1) /* tape drive? */ goto yes; if (hostdata->disconnected_Q) /* other commands disconnected? */ goto yes; if (!(hostdata->input_Q)) /* input_Q empty? */ goto no; for (prev = (struct scsi_cmnd *) hostdata->input_Q; prev;
prev = (struct scsi_cmnd *) prev->host_scribble) { if ((prev->device->id != cmd->device->id) ||
(prev->device->lun != cmd->device->lun)) { for (prev = (struct scsi_cmnd *) hostdata->input_Q; prev;
prev = (struct scsi_cmnd *) prev->host_scribble)
WD33C93_scsi_pointer(prev)->phase = 1; goto yes;
}
}
if ((hostdata->level2 == L2_NONE) ||
(hostdata->sync_stat[cmd->device->id] == SS_UNSET)) {
/* * Do a 'Select-With-ATN' command. This will end with * one of the following interrupts: * CSR_RESEL_AM: failure - can try again later. * CSR_TIMEOUT: failure - give up. * CSR_SELECT: success - proceed.
*/
hostdata->selecting = cmd;
/* Every target has its own synchronous transfer setting, kept in the * sync_xfer array, and a corresponding status byte in sync_stat[]. * Each target's sync_stat[] entry is initialized to SX_UNSET, and its * sync_xfer[] entry is initialized to the default/safe value. SS_UNSET * means that the parameters are undetermined as yet, and that we * need to send an SDTR message to this device after selection is * complete: We set SS_FIRST to tell the interrupt routine to do so. * If we've been asked not to try synchronous transfers on this * target (and _all_ luns within it), we'll still send the SDTR message * later, but at that time we'll negotiate for async by specifying a * sync fifo depth of 0.
*/ if (hostdata->sync_stat[cmd->device->id] == SS_UNSET)
hostdata->sync_stat[cmd->device->id] = SS_FIRST;
hostdata->state = S_SELECTING;
write_wd33c93_count(regs, 0); /* guarantee a DATA_PHASE interrupt */
write_wd33c93_cmd(regs, WD_CMD_SEL_ATN);
} else {
/* * Do a 'Select-With-ATN-Xfer' command. This will end with * one of the following interrupts: * CSR_RESEL_AM: failure - can try again later. * CSR_TIMEOUT: failure - give up. * anything else: success - proceed.
*/
/* copy command_descriptor_block into WD chip * (take advantage of auto-incrementing)
*/
write_wd33c93_cdb(regs, cmd->cmd_len, cmd->cmnd);
/* The wd33c93 only knows about Group 0, 1, and 5 commands when * it's doing a 'select-and-transfer'. To be safe, we write the * size of the CDB into the OWN_ID register for every case. This * way there won't be problems with vendor-unique, audio, etc.
*/
write_wd33c93(regs, WD_OWN_ID, cmd->cmd_len);
/* When doing a non-disconnect command with DMA, we can save * ourselves a DATA phase interrupt later by setting everything * up ahead of time.
*/
/* * Since the SCSI bus can handle only 1 connection at a time, * we get out of here now. If the selection fails, or when * the command disconnects, we'll come back to this routine * to search the input_Q again...
*/
write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
write_wd33c93_count(regs, cnt);
write_wd33c93_cmd(regs, WD_CMD_TRANS_INFO); if (data_in_dir) { do {
asr = read_aux_stat(regs); if (asr & ASR_DBR)
*buf++ = read_wd33c93(regs, WD_DATA);
} while (!(asr & ASR_INT));
} else { do {
asr = read_aux_stat(regs); if (asr & ASR_DBR)
write_wd33c93(regs, WD_DATA, *buf++);
} while (!(asr & ASR_INT));
}
/* Note: we are returning with the interrupt UN-cleared. * Since (presumably) an entire I/O operation has * completed, the bus phase is probably different, and * the interrupt routine will discover this when it * responds to the uncleared int.
*/
/* Normally, you'd expect 'this_residual' to be non-zero here. * In a series of scatter-gather transfers, however, this * routine will usually be called with 'this_residual' equal * to 0 and 'buffers_residual' non-zero. This means that a * previous transfer completed, clearing 'this_residual', and * now we need to setup the next scatter-gather buffer as the * source or destination for THIS transfer.
*/ if (!scsi_pointer->this_residual && scsi_pointer->buffers_residual) {
scsi_pointer->buffer = sg_next(scsi_pointer->buffer);
--scsi_pointer->buffers_residual;
scsi_pointer->this_residual = scsi_pointer->buffer->length;
scsi_pointer->ptr = sg_virt(scsi_pointer->buffer);
} if (!scsi_pointer->this_residual) /* avoid bogus setups */ return;
/* We are able to do DMA (in fact, the Amiga hardware is * already going!), so start up the wd33c93 in DMA mode. * We set 'hostdata->dma' = D_DMA_RUNNING so that when the * transfer completes and causes an interrupt, we're * reminded to tell the Amiga to shut down its end. We'll * postpone the updating of 'this_residual' and 'ptr' * until then.
*/
/* After starting a DMA transfer, the next interrupt * is guaranteed to be in response to completion of * the transfer. Since the Amiga DMA hardware runs in * in an open-ended fashion, it needs to be told when * to stop; do that here if D_DMA_RUNNING is true. * Also, we have to update 'this_residual' and 'ptr' * based on the contents of the TRANSFER_COUNT register, * in case the device decided to do an intermediate * disconnect (a device may do this if it has to do a * seek, or just to be nice and let other devices have * some bus time during long transfers). After doing * whatever is needed, we go on and service the WD3393 * interrupt normally.
*/ if (hostdata->dma == D_DMA_RUNNING) {
DB(DB_TRANSFER,
printk("[%p/%d:", scsi_pointer->ptr, scsi_pointer->this_residual))
hostdata->dma_stop(cmd->device->host, cmd, 1);
hostdata->dma = D_DMA_OFF;
length = scsi_pointer->this_residual;
scsi_pointer->this_residual = read_wd33c93_count(regs);
scsi_pointer->ptr += length - scsi_pointer->this_residual;
DB(DB_TRANSFER,
printk("%p/%d]", scsi_pointer->ptr, scsi_pointer->this_residual))
}
/* Respond to the specific WD3393 interrupt - there are quite a few! */ switch (sr) { case CSR_TIMEOUT:
DB(DB_INTR, printk("TIMEOUT"))
if (hostdata->state == S_RUNNING_LEVEL2)
hostdata->connected = NULL; else {
cmd = (struct scsi_cmnd *) hostdata->selecting; /* get a valid cmd */
hostdata->selecting = NULL;
}
/* From esp.c: * There is a window of time within the scsi_done() path * of execution where interrupts are turned back on full * blast and left that way. During that time we could * reconnect to a disconnected command, then we'd bomb * out below. We could also end up executing two commands * at _once_. ...just so you know why the restore_flags() * is here...
*/
spin_unlock_irqrestore(&hostdata->lock, flags);
/* We are not connected to a target - check to see if there * are commands waiting to be executed.
*/
wd33c93_execute(instance); break;
/* Note: this interrupt should not occur in a LEVEL2 command */
/* Tack on a 2nd message to ask about synchronous transfers. If we've * been asked to do only asynchronous transfers on this device, we * request a fifo depth of 0, which is equivalent to async - should * solve the problems some people have had with GVP's Guru ROM.
*/
switch (ucp[2]) { /* what's the EXTENDED code? */ case EXTENDED_SDTR: /* default to default async period */
id = calc_sync_xfer(hostdata->
default_sx_per / 4, 0,
0, hostdata->sx_table); if (hostdata->sync_stat[cmd->device->id] !=
SS_WAITING) {
/* A device has sent an unsolicited SDTR message; rather than go * through the effort of decoding it and then figuring out what * our reply should be, we're just gonna say that we have a * synchronous fifo depth of 0. This will result in asynchronous * transfers - not ideal but so much easier. * Actually, this is OK because it assures us that if we don't * specifically ask for sync transfers, we won't do any.
*/
/* We are no longer connected to a target - check to see if * there are commands waiting to be executed.
*/
spin_unlock_irqrestore(&hostdata->lock, flags);
wd33c93_execute(instance);
} else {
printk
("%02x:%02x:%02x: Unknown SEL_XFER_DONE phase!!---",
asr, sr, phs);
spin_unlock_irqrestore(&hostdata->lock, flags);
} break;
/* Note: this interrupt will occur only after a LEVEL2 command */
case CSR_XFER_DONE | PHS_MESS_OUT: case CSR_UNEXP | PHS_MESS_OUT: case CSR_SRV_REQ | PHS_MESS_OUT:
DB(DB_INTR, printk("MSG_OUT="))
/* To get here, we've probably requested MESSAGE_OUT and have * already put the correct bytes in outgoing_msg[] and filled * in outgoing_len. We simply send them out to the SCSI bus. * Sometimes we get MESSAGE_OUT phase when we're not expecting * it - like when our SDTR message is rejected by a target. Some * targets send the REJECT before receiving all of the extended * message, and then seem to go back to MESSAGE_OUT for a byte * or two. Not sure why, or if I'm doing something wrong to * cause this to happen. Regardless, it seems that sending * NOP messages in these situations results in no harm and * makes everyone happy.
*/ if (hostdata->outgoing_len == 0) {
hostdata->outgoing_len = 1;
hostdata->outgoing_msg[0] = NOP;
}
transfer_pio(regs, hostdata->outgoing_msg,
hostdata->outgoing_len, DATA_OUT_DIR, hostdata);
DB(DB_INTR, printk("%02x", hostdata->outgoing_msg[0]))
hostdata->outgoing_len = 0;
hostdata->state = S_CONNECTED;
spin_unlock_irqrestore(&hostdata->lock, flags); break;
case CSR_UNEXP_DISC:
/* I think I've seen this after a request-sense that was in response * to an error condition, but not sure. We certainly need to do * something when we get this interrupt - the question is 'what?'. * Let's think positively, and assume some command has finished * in a legal manner (like a command that provokes a request-sense), * so we treat it as a normal command-complete-disconnect.
*/
/* Make sure that reselection is enabled at this point - it may * have been turned off for the command that just completed.
*/
/* We are no longer connected to a target - check to see if * there are commands waiting to be executed.
*/ /* look above for comments on scsi_done() */
spin_unlock_irqrestore(&hostdata->lock, flags);
wd33c93_execute(instance); break;
case CSR_DISC:
/* Make sure that reselection is enabled at this point - it may * have been turned off for the command that just completed.
*/
/* We are no longer connected to a target - check to see if * there are commands waiting to be executed.
*/
spin_unlock_irqrestore(&hostdata->lock, flags);
wd33c93_execute(instance); break;
case CSR_RESEL_AM: case CSR_RESEL:
DB(DB_INTR, printk("RESEL%s", sr == CSR_RESEL_AM ? "_AM" : ""))
/* Old chips (pre -A ???) don't have advanced features and will * generate CSR_RESEL. In that case we have to extract the LUN the * hard way (see below). * First we have to make sure this reselection didn't * happen during Arbitration/Selection of some other device. * If yes, put losing command back on top of input_Q.
*/ if (hostdata->level2 <= L2_NONE) {
id = read_wd33c93(regs, WD_SOURCE_ID);
id &= SRCID_MASK;
/* and extract the lun from the ID message. (Note that we don't * bother to check for a valid message here - I guess this is * not the right way to go, but...)
*/
if (sr == CSR_RESEL_AM) {
lun = read_wd33c93(regs, WD_DATA); if (hostdata->level2 < L2_RESELECT)
write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
lun &= 7;
} else { /* Old chip; wait for msgin phase to pick up the LUN. */ for (lun = 255; lun; lun--) { if ((asr = read_aux_stat(regs)) & ASR_INT) break;
udelay(10);
} if (!(asr & ASR_INT)) {
printk
("wd33c93: Reselected without IDENTIFY\n");
lun = 0;
} else { /* Verify this is a change to MSG_IN and read the message */
sr = read_wd33c93(regs, WD_SCSI_STATUS);
udelay(7); if (sr == (CSR_ABORT | PHS_MESS_IN) ||
sr == (CSR_UNEXP | PHS_MESS_IN) ||
sr == (CSR_SRV_REQ | PHS_MESS_IN)) { /* Got MSG_IN, grab target LUN */
lun = read_1_byte(regs); /* Now we expect a 'paused with ACK asserted' int.. */
asr = read_aux_stat(regs); if (!(asr & ASR_INT)) {
udelay(10);
asr = read_aux_stat(regs); if (!(asr & ASR_INT))
printk
("wd33c93: No int after LUN on RESEL (%02x)\n",
asr);
}
sr = read_wd33c93(regs, WD_SCSI_STATUS);
udelay(7); if (sr != CSR_MSGIN)
printk
("wd33c93: Not paused with ACK on RESEL (%02x)\n",
sr);
lun &= 7;
write_wd33c93_cmd(regs,
WD_CMD_NEGATE_ACK);
} else {
printk
("wd33c93: Not MSG_IN on reselect (%02x)\n",
sr);
lun = 0;
}
}
}
/* Now we look for the command that's reconnecting. */
/* We don't need to worry about 'initialize_SCp()' or 'hostdata->busy[]' * because these things are preserved over a disconnect. * But we DO need to fix the DPD bit so it's correct for this command.
*/
if (cmd->sc_data_direction == DMA_TO_DEVICE)
write_wd33c93(regs, WD_DESTINATION_ID, cmd->device->id); else
write_wd33c93(regs, WD_DESTINATION_ID,
cmd->device->id | DSTID_DPD); if (hostdata->level2 >= L2_RESELECT) {
write_wd33c93_count(regs, 0); /* we want a DATA_PHASE interrupt */
write_wd33c93(regs, WD_COMMAND_PHASE, 0x45);
write_wd33c93_cmd(regs, WD_CMD_SEL_ATN_XFER);
hostdata->state = S_RUNNING_LEVEL2;
} else
hostdata->state = S_CONNECTED;
#ifdef CONFIG_SGI_IP22
{ int busycount = 0; externvoid sgiwd93_reset(unsignedlong); /* wait 'til the chip gets some time for us */ while ((read_aux_stat(regs) & ASR_BSY) && busycount++ < 100)
udelay (10); /* * there are scsi devices out there, which manage to lock up * the wd33c93 in a busy condition. In this state it won't * accept the reset command. The only way to solve this is to * give the chip a hardware reset (if possible). The code below * does this for the SGI Indy, where this is possible
*/ /* still busy ? */ if (read_aux_stat(regs) & ASR_BSY)
sgiwd93_reset(instance->base); /* yeah, give it the hard one */
} #endif
/* * Case 2 : If the command is connected, we're going to fail the abort * and let the high level SCSI driver retry at a later time or * issue a reset. * * Timeouts, and therefore aborted commands, will be highly unlikely * and handling them cleanly in this situation would make the common * case of noresets less efficient, and would pollute our code. So, * we fail.
*/
if (hostdata->connected == cmd) {
uchar sr, asr; unsignedlong timeout;
/* * Case 3: If the command is currently disconnected from the bus, * we're not going to expend much effort here: Let's just return * an ABORT_SNOOZE and hope for the best...
*/
tmp = (struct scsi_cmnd *) hostdata->disconnected_Q; while (tmp) { if (tmp == cmd) {
printk
("scsi%d: Abort - command found on disconnected_Q - ",
instance->host_no);
printk("Abort SNOOZE. ");
enable_irq(cmd->device->host->irq); return FAILED;
}
tmp = (struct scsi_cmnd *) tmp->host_scribble;
}
/* * Case 4 : If we reached this point, the command was not found in any of * the queues. * * We probably reached this point because of an unlikely race condition * between the command completing successfully and the abortion code, * so we won't panic, but we will notify the user in case something really * broke.
*/
staticint
wd33c93_setup(char *str)
{ int i; char *p1, *p2;
/* The kernel does some processing of the command-line before calling * this function: If it begins with any decimal or hex number arguments, * ints[0] = how many numbers found and ints[1] through [n] are the values * themselves. str points to where the non-numeric arguments (if any) * start: We do our own parsing of those. We construct synthetic 'nosync' * keywords out of numeric args (to maintain compatibility with older * versions) and then add the rest of the arguments.
*/
p1 = setup_buffer;
*p1 = '\0'; if (str)
strscpy(p1, str, SETUP_BUFFER_SIZE);
i = 0; while (*p1 && (i < MAX_SETUP_ARGS)) {
p2 = strchr(p1, ','); if (p2) {
*p2 = '\0'; if (p1 != p2)
setup_args[i] = p1;
p1 = p2 + 1;
i++;
} else {
setup_args[i] = p1; break;
}
} for (i = 0; i < MAX_SETUP_ARGS; i++)
setup_used[i] = 0;
done_setup = 1;
return 1;
}
__setup("wd33c93=", wd33c93_setup);
/* check_setup_args() returns index if key found, 0 if not
*/ staticint
check_setup_args(char *key, int *flags, int *val, char *buf)
{ int x; char *cp;
for (x = 0; x < MAX_SETUP_ARGS; x++) { if (setup_used[x]) continue; if (!strncmp(setup_args[x], key, strlen(key))) break; if (!strncmp(setup_args[x], "next", strlen("next"))) return 0;
} if (x == MAX_SETUP_ARGS) return 0;
setup_used[x] = 1;
cp = setup_args[x] + strlen(key);
*val = -1; if (*cp != ':') return ++x;
cp++; if ((*cp >= '0') && (*cp <= '9')) {
*val = simple_strtoul(cp, NULL, 0);
} return ++x;
}
/* * Calculate internal data-transfer-clock cycle from input-clock * frequency (/MHz) and fill 'sx_table'. * * The original driver used to rely on a fixed sx_table, containing periods * for (only) the lower limits of the respective input-clock-frequency ranges * (8-10/12-15/16-20 MHz). Although it seems, that no problems occurred with * this setting so far, it might be desirable to adjust the transfer periods * closer to the really attached, possibly 25% higher, input-clock, since * - the wd33c93 may really use a significant shorter period, than it has * negotiated (eg. thrashing the target, which expects 4/8MHz, with 5/10MHz * instead). * - the wd33c93 may ask the target for a lower transfer rate, than the target * is capable of (eg. negotiating for an assumed minimum of 252ns instead of * possible 200ns, which indeed shows up in tests as an approx. 10% lower * transfer rate).
*/ staticinlineunsignedint
round_4(unsignedint x)
{ switch (x & 3) { case 1: --x; break; case 2: ++x;
fallthrough; case 3: ++x;
} return x;
}
staticvoid
calc_sx_table(unsignedint mhz, struct sx_period sx_table[9])
{ unsignedint d, i; if (mhz < 11)
d = 2; /* divisor for 8-10 MHz input-clock */ elseif (mhz < 16)
d = 3; /* divisor for 12-15 MHz input-clock */ else
d = 4; /* divisor for 16-20 MHz input-clock */
d = (100000 * d) / 2 / mhz; /* 100 x DTCC / nanosec */
/* * check and, maybe, map an init- or "clock:"- argument.
*/ static uchar
set_clk_freq(int freq, int *mhz)
{ int x = freq; if (WD33C93_FS_8_10 == freq)
freq = 8; elseif (WD33C93_FS_12_15 == freq)
freq = 12; elseif (WD33C93_FS_16_20 == freq)
freq = 16; elseif (freq > 7 && freq < 11)
x = WD33C93_FS_8_10; elseif (freq > 11 && freq < 16)
x = WD33C93_FS_12_15; elseif (freq > 15 && freq < 21)
x = WD33C93_FS_16_20; else { /* Hmm, wouldn't it be safer to assume highest freq here? */
x = WD33C93_FS_8_10;
freq = 8;
}
*mhz = freq; return x;
}
/* * to be used with the resync: fast: ... options
*/ staticinlinevoid set_resync ( struct WD33C93_hostdata *hd, int mask )
{ int i; for (i = 0; i < 8; i++) if (mask & (1 << i))
hd->sync_stat[i] = SS_UNSET;
}
void
wd33c93_init(struct Scsi_Host *instance, const wd33c93_regs regs,
dma_setup_t setup, dma_stop_t stop, int clock_freq)
{ struct WD33C93_hostdata *hostdata; int i; int flags; int val; char buf[32];
if (!done_setup && setup_strings)
wd33c93_setup(setup_strings);
int wd33c93_write_info(struct Scsi_Host *instance, char *buf, int len)
{ #ifdef PROC_INTERFACE char *bp; struct WD33C93_hostdata *hd; int x;
hd = (struct WD33C93_hostdata *) instance->hostdata;
/* We accept the following * keywords (same format as command-line, but arguments are not optional): * debug * disconnect * period * resync * proc * nodma * level2 * burst * fast * nosync
*/
Die Informationen auf dieser Webseite wurden
nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit,
noch Qualität der bereit gestellten Informationen zugesichert.
Bemerkung:
Die farbliche Syntaxdarstellung und die Messung sind noch experimentell.
