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Diffstat (limited to 'drivers/scsi/in2000.c')
| -rw-r--r-- | drivers/scsi/in2000.c | 2323 |
1 files changed, 2323 insertions, 0 deletions
diff --git a/drivers/scsi/in2000.c b/drivers/scsi/in2000.c new file mode 100644 index 00000000000..0bb0369efb2 --- /dev/null +++ b/drivers/scsi/in2000.c @@ -0,0 +1,2323 @@ +/* + * in2000.c - Linux device driver for the + * Always IN2000 ISA SCSI card. + * + * Copyright (c) 1996 John Shifflett, GeoLog Consulting + * john@geolog.com + * jshiffle@netcom.com + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * For the avoidance of doubt the "preferred form" of this code is one which + * is in an open non patent encumbered format. Where cryptographic key signing + * forms part of the process of creating an executable the information + * including keys needed to generate an equivalently functional executable + * are deemed to be part of the source code. + * + * Drew Eckhardt's excellent 'Generic NCR5380' sources provided + * much of the inspiration and some of the code for this driver. + * The Linux IN2000 driver distributed in the Linux kernels through + * version 1.2.13 was an extremely valuable reference on the arcane + * (and still mysterious) workings of the IN2000's fifo. It also + * is where I lifted in2000_biosparam(), the gist of the card + * detection scheme, and other bits of code. Many thanks to the + * talented and courageous people who wrote, contributed to, and + * maintained that driver (including Brad McLean, Shaun Savage, + * Bill Earnest, Larry Doolittle, Roger Sunshine, John Luckey, + * Matt Postiff, Peter Lu, zerucha@shell.portal.com, and Eric + * Youngdale). I should also mention the driver written by + * Hamish Macdonald for the (GASP!) Amiga A2091 card, included + * in the Linux-m68k distribution; it gave me a good initial + * understanding of the proper way to run a WD33c93 chip, and I + * ended up stealing lots of code from it. + * + * _This_ driver is (I feel) an improvement over the old one in + * several respects: + * - All problems relating to the data size of a SCSI request are + * gone (as far as I know). The old driver couldn't handle + * swapping to partitions because that involved 4k blocks, nor + * could it deal with the st.c tape driver unmodified, because + * that usually involved 4k - 32k blocks. The old driver never + * quite got away from a morbid dependence on 2k block sizes - + * which of course is the size of the card's fifo. + * + * - 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'm + * calling '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 there + * are a few devices (and many improperly terminated systems) + * that choke when doing sync, the default is sync DISABLED + * for all devices. This faster protocol can (and should!) + * be enabled on selected devices via the command-line. + * + * - Runtime operating parameters can now be specified through + * either the LILO or the 'insmod' command line. For LILO do: + * "in2000=blah,blah,blah" + * and with insmod go like: + * "insmod /usr/src/linux/modules/in2000.o setup_strings=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. + * + * - You can force detection of a card whose BIOS has been disabled. + * + * - Multiple IN2000 cards might almost be supported. I've tried to + * keep it in mind, but have no way to test... + * + * + * TODO: + * tagged queuing. multiple cards. + * + * + * NOTE: + * When using this or any other SCSI driver as a module, you'll + * find that with the stock kernel, at most _two_ SCSI hard + * drives will be linked into the device list (ie, usable). + * If your IN2000 card has more than 2 disks on its bus, you + * might want to change the define of 'SD_EXTRA_DEVS' in the + * 'hosts.h' file from 2 to whatever is appropriate. It took + * me a while to track down this surprisingly obscure and + * undocumented little "feature". + * + * + * 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". + * + * Updated for Linux 2.5 by Alan Cox <alan@redhat.com> + * - Using new_eh handler + * - Hopefully got all the locking right again + * See "FIXME" notes for items that could do with more work + */ + +#include <linux/module.h> +#include <linux/blkdev.h> +#include <linux/interrupt.h> +#include <linux/string.h> +#include <linux/delay.h> +#include <linux/proc_fs.h> +#include <linux/ioport.h> +#include <linux/stat.h> + +#include <asm/io.h> +#include <asm/system.h> + +#include "scsi.h" +#include <scsi/scsi_host.h> + +#define IN2000_VERSION "1.33-2.5" +#define IN2000_DATE "2002/11/03" + +#include "in2000.h" + + +/* + * '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 a LILO or insmod command-line, those + * settings are combined with 'setup_args[]'. Note that LILO command-lines + * are prefixed with "in2000=" while insmod uses a "setup_strings=" prefix. + * The driver recognizes the following keywords (lower case required) and + * arguments: + * + * - ioport:addr -Where addr is IO address of a (usually ROM-less) card. + * - noreset -No optional args. Prevents SCSI bus reset at boot time. + * - nosync:x -x is a bitmask where the 1st 7 bits correspond with + * the 7 possible SCSI devices (bit 0 for device #0, etc). + * Set a bit to PREVENT sync negotiation on that device. + * The driver default is sync DISABLED on all devices. + * - 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 bitmask that causes + * various types of debug output to printed - see the DB_xxx + * defines in in2000.h + * - proc:x -If 'PROC_INTERFACE' is defined, x is a bitmask that + * determines how the /proc interface works and what it + * does - see the PR_xxx defines in in2000.h + * + * 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. + * + * A few LILO examples (for insmod, use 'setup_strings' instead of 'in2000'): + * - in2000=ioport:0x220,noreset + * - in2000=period:250,disconnect:2,nosync:0x03 + * - in2000=debug:0x1e + * - in2000=proc:3 + */ + +/* Normally, no defaults are specified... */ +static char *setup_args[] = { "", "", "", "", "", "", "", "", "" }; + +/* filled in by 'insmod' */ +static char *setup_strings; + +module_param(setup_strings, charp, 0); + +static inline uchar read_3393(struct IN2000_hostdata *hostdata, uchar reg_num) +{ + write1_io(reg_num, IO_WD_ADDR); + return read1_io(IO_WD_DATA); +} + + +#define READ_AUX_STAT() read1_io(IO_WD_ASR) + + +static inline void write_3393(struct IN2000_hostdata *hostdata, uchar reg_num, uchar value) +{ + write1_io(reg_num, IO_WD_ADDR); + write1_io(value, IO_WD_DATA); +} + + +static inline void write_3393_cmd(struct IN2000_hostdata *hostdata, uchar cmd) +{ +/* while (READ_AUX_STAT() & ASR_CIP) + printk("|");*/ + write1_io(WD_COMMAND, IO_WD_ADDR); + write1_io(cmd, IO_WD_DATA); +} + + +static uchar read_1_byte(struct IN2000_hostdata *hostdata) +{ + uchar asr, x = 0; + + write_3393(hostdata, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED); + write_3393_cmd(hostdata, WD_CMD_TRANS_INFO | 0x80); + do { + asr = READ_AUX_STAT(); + if (asr & ASR_DBR) + x = read_3393(hostdata, WD_DATA); + } while (!(asr & ASR_INT)); + return x; +} + + +static void write_3393_count(struct IN2000_hostdata *hostdata, unsigned long value) +{ + write1_io(WD_TRANSFER_COUNT_MSB, IO_WD_ADDR); + write1_io((value >> 16), IO_WD_DATA); + write1_io((value >> 8), IO_WD_DATA); + write1_io(value, IO_WD_DATA); +} + + +static unsigned long read_3393_count(struct IN2000_hostdata *hostdata) +{ + unsigned long value; + + write1_io(WD_TRANSFER_COUNT_MSB, IO_WD_ADDR); + value = read1_io(IO_WD_DATA) << 16; + value |= read1_io(IO_WD_DATA) << 8; + value |= read1_io(IO_WD_DATA); + return value; +} + + +/* The 33c93 needs to be told which direction a command transfers its + * data; we use this function to figure it out. Returns true if there + * will be a DATA_OUT phase with this command, false otherwise. + * (Thanks to Joerg Dorchain for the research and suggestion.) + */ +static int is_dir_out(Scsi_Cmnd * cmd) +{ + switch (cmd->cmnd[0]) { + case WRITE_6: + case WRITE_10: + case WRITE_12: + case WRITE_LONG: + case WRITE_SAME: + case WRITE_BUFFER: + case WRITE_VERIFY: + case WRITE_VERIFY_12: + case COMPARE: + case COPY: + case COPY_VERIFY: + case SEARCH_EQUAL: + case SEARCH_HIGH: + case SEARCH_LOW: + case SEARCH_EQUAL_12: + case SEARCH_HIGH_12: + case SEARCH_LOW_12: + case FORMAT_UNIT: + case REASSIGN_BLOCKS: + case RESERVE: + case MODE_SELECT: + case MODE_SELECT_10: + case LOG_SELECT: + case SEND_DIAGNOSTIC: + case CHANGE_DEFINITION: + case UPDATE_BLOCK: + case SET_WINDOW: + case MEDIUM_SCAN: + case SEND_VOLUME_TAG: + case 0xea: + return 1; + default: + return 0; + } +} + + + +static struct sx_period sx_table[] = { + {1, 0x20}, + {252, 0x20}, + {376, 0x30}, + {500, 0x40}, + {624, 0x50}, + {752, 0x60}, + {876, 0x70}, + {1000, 0x00}, + {0, 0} +}; + +static int round_period(unsigned int period) +{ + int x; + + for (x = 1; sx_table[x].period_ns; x++) { + if ((period <= sx_table[x - 0].period_ns) && (period > sx_table[x - 1].period_ns)) { + return x; + } + } + return 7; +} + +static uchar calc_sync_xfer(unsigned int period, unsigned int offset) +{ + uchar result; + + period *= 4; /* convert SDTR code to ns */ + result = sx_table[round_period(period)].reg_value; + result |= (offset < OPTIMUM_SX_OFF) ? offset : OPTIMUM_SX_OFF; + return result; +} + + + +static void in2000_execute(struct Scsi_Host *instance); + +static int in2000_queuecommand(Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *)) +{ + struct Scsi_Host *instance; + struct IN2000_hostdata *hostdata; + Scsi_Cmnd *tmp; + + instance = cmd->device->host; + hostdata = (struct IN2000_hostdata *) instance->hostdata; + + DB(DB_QUEUE_COMMAND, printk("Q-%d-%02x-%ld(", cmd->device->id, cmd->cmnd[0], cmd->pid)) + +/* 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 + * - scsi_done points to the routine we call when a cmd is finished + * - result is what you'd expect + */ + cmd->host_scribble = NULL; + cmd->scsi_done = done; + 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 helps keep track of >2048 byte transfers + * - SCp.sent_command is not used + * - SCp.phase records this command's SRCID_ER bit setting + */ + + if (cmd->use_sg) { + cmd->SCp.buffer = (struct scatterlist *) cmd->buffer; + cmd->SCp.buffers_residual = cmd->use_sg - 1; + cmd->SCp.ptr = (char *) page_address(cmd->SCp.buffer->page) + cmd->SCp.buffer->offset; + cmd->SCp.this_residual = cmd->SCp.buffer->length; + } else { + cmd->SCp.buffer = NULL; + cmd->SCp.buffers_residual = 0; + cmd->SCp.ptr = (char *) cmd->request_buffer; + cmd->SCp.this_residual = cmd->request_bufflen; + } + cmd->SCp.have_data_in = 0; + +/* We don't set SCp.phase here - that's done in in2000_execute() */ + +/* 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. + */ + + cmd->SCp.Status = ILLEGAL_STATUS_BYTE; + +/* We need to disable interrupts before messing with the input + * queue and calling in2000_execute(). + */ + + /* + * 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. + */ + + 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 = (Scsi_Cmnd *) hostdata->input_Q; tmp->host_scribble; tmp = (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! + */ + + in2000_execute(cmd->device->host); + + DB(DB_QUEUE_COMMAND, printk(")Q-%ld ", cmd->pid)) + return 0; +} + + + +/* + * 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. + * Note that this function is always called with interrupts already + * disabled (either from in2000_queuecommand() or in2000_intr()). + */ +static void in2000_execute(struct Scsi_Host *instance) +{ + struct IN2000_hostdata *hostdata; + Scsi_Cmnd *cmd, *prev; + int i; + unsigned short *sp; + unsigned short f; + unsigned short flushbuf[16]; + + + hostdata = (struct IN2000_hostdata *) instance->hostdata; + + DB(DB_EXECUTE, printk("EX(")) + + if (hostdata->selecting || hostdata->connected) { + + DB(DB_EXECUTE, printk(")EX-0 ")) + + return; + } + + /* + * Search through the input_Q for a command destined + * for an idle target/lun. + */ + + cmd = (Scsi_Cmnd *) hostdata->input_Q; + prev = NULL; + while (cmd) { + if (!(hostdata->busy[cmd->device->id] & (1 << cmd->device->lun))) + break; + prev = cmd; + cmd = (Scsi_Cmnd *) cmd->host_scribble; + } + + /* quit if queue empty or all possible targets are busy */ + + if (!cmd) { + + DB(DB_EXECUTE, printk(")EX-1 ")) + + return; + } + + /* remove command from queue */ + + if (prev) + prev->host_scribble = cmd->host_scribble; + else + hostdata->input_Q = (Scsi_Cmnd *) cmd->host_scribble; + +#ifdef PROC_STATISTICS + hostdata->cmd_cnt[cmd->device->id]++; +#endif + +/* + * Start the selection process + */ + + if (is_dir_out(cmd)) + write_3393(hostdata, WD_DESTINATION_ID, cmd->device->id); + else + write_3393(hostdata, WD_DESTINATION_ID, cmd->device->id | DSTID_DPD); + +/* 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. + */ + + cmd->SCp.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 = (Scsi_Cmnd *) hostdata->input_Q; prev; prev = (Scsi_Cmnd *) prev->host_scribble) { + if ((prev->device->id != cmd->device->id) || (prev->device->lun != cmd->device->lun)) { + for (prev = (Scsi_Cmnd *) hostdata->input_Q; prev; prev = (Scsi_Cmnd *) prev->host_scribble) + prev->SCp.phase = 1; + goto yes; + } + } + goto no; + + yes: + cmd->SCp.phase = 1; + +#ifdef PROC_STATISTICS + hostdata->disc_allowed_cnt[cmd->device->id]++; +#endif + + no: + write_3393(hostdata, WD_SOURCE_ID, ((cmd->SCp.phase) ? SRCID_ER : 0)); + + write_3393(hostdata, WD_TARGET_LUN, cmd->device->lun); + write_3393(hostdata, WD_SYNCHRONOUS_TRANSFER, hostdata->sync_xfer[cmd->device->id]); + hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun); + + 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 SS_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, + * unless we don't want to even _try_ synchronous transfers: In this + * case we set SS_SET to make the defaults final. + */ + if (hostdata->sync_stat[cmd->device->id] == SS_UNSET) { + if (hostdata->sync_off & (1 << cmd->device->id)) + hostdata->sync_stat[cmd->device->id] = SS_SET; + else + hostdata->sync_stat[cmd->device->id] = SS_FIRST; + } + hostdata->state = S_SELECTING; + write_3393_count(hostdata, 0); /* this guarantees a DATA_PHASE interrupt */ + write_3393_cmd(hostdata, 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. + */ + + hostdata->connected = cmd; + write_3393(hostdata, WD_COMMAND_PHASE, 0); + + /* copy command_descriptor_block into WD chip + * (take advantage of auto-incrementing) + */ + + write1_io(WD_CDB_1, IO_WD_ADDR); + for (i = 0; i < cmd->cmd_len; i++) + write1_io(cmd->cmnd[i], IO_WD_DATA); + + /* 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_3393(hostdata, WD_OWN_ID, cmd->cmd_len); + + /* When doing a non-disconnect command, we can save ourselves a DATA + * phase interrupt later by setting everything up now. With writes we + * need to pre-fill the fifo; if there's room for the 32 flush bytes, + * put them in there too - that'll avoid a fifo interrupt. Reads are + * somewhat simpler. + * KLUDGE NOTE: It seems that you can't completely fill the fifo here: + * This results in the IO_FIFO_COUNT register rolling over to zero, + * and apparently the gate array logic sees this as empty, not full, + * so the 3393 chip is never signalled to start reading from the + * fifo. Or maybe it's seen as a permanent fifo interrupt condition. + * Regardless, we fix this by temporarily pretending that the fifo + * is 16 bytes smaller. (I see now that the old driver has a comment + * about "don't fill completely" in an analogous place - must be the + * same deal.) This results in CDROM, swap partitions, and tape drives + * needing an extra interrupt per write command - I think we can live + * with that! + */ + + if (!(cmd->SCp.phase)) { + write_3393_count(hostdata, cmd->SCp.this_residual); + write_3393(hostdata, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_BUS); + write1_io(0, IO_FIFO_WRITE); /* clear fifo counter, write mode */ + + if (is_dir_out(cmd)) { + hostdata->fifo = FI_FIFO_WRITING; + if ((i = cmd->SCp.this_residual) > (IN2000_FIFO_SIZE - 16)) + i = IN2000_FIFO_SIZE - 16; + cmd->SCp.have_data_in = i; /* this much data in fifo */ + i >>= 1; /* Gulp. Assuming modulo 2. */ + sp = (unsigned short *) cmd->SCp.ptr; + f = hostdata->io_base + IO_FIFO; + +#ifdef FAST_WRITE_IO + + FAST_WRITE2_IO(); +#else + while (i--) + write2_io(*sp++, IO_FIFO); + +#endif + + /* Is there room for the flush bytes? */ + + if (cmd->SCp.have_data_in <= ((IN2000_FIFO_SIZE - 16) - 32)) { + sp = flushbuf; + i = 16; + +#ifdef FAST_WRITE_IO + + FAST_WRITE2_IO(); +#else + while (i--) + write2_io(0, IO_FIFO); + +#endif + + } + } + + else { + write1_io(0, IO_FIFO_READ); /* put fifo in read mode */ + hostdata->fifo = FI_FIFO_READING; + cmd->SCp.have_data_in = 0; /* nothing transferred yet */ + } + + } else { + write_3393_count(hostdata, 0); /* this guarantees a DATA_PHASE interrupt */ + } + hostdata->state = S_RUNNING_LEVEL2; + write_3393_cmd(hostdata, WD_CMD_SEL_ATN_XFER); + } + + /* + * 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... + */ + + DB(DB_EXECUTE, printk("%s%ld)EX-2 ", (cmd->SCp.phase) ? "d:" : "", cmd->pid)) + +} + + + +static void transfer_pio(uchar * buf, int cnt, int data_in_dir, struct IN2000_hostdata *hostdata) +{ + uchar asr; + + DB(DB_TRANSFER, printk("(%p,%d,%s)", buf, cnt, data_in_dir ? "in" : "out")) + + write_3393(hostdata, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED); + write_3393_count(hostdata, cnt); + write_3393_cmd(hostdata, WD_CMD_TRANS_INFO); + if (data_in_dir) { + do { + asr = READ_AUX_STAT(); + if (asr & ASR_DBR) + *buf++ = read_3393(hostdata, WD_DATA); + } while (!(asr & ASR_INT)); + } else { + do { + asr = READ_AUX_STAT(); + if (asr & ASR_DBR) + write_3393(hostdata, 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. + */ + +} + + + +static void transfer_bytes(Scsi_Cmnd * cmd, int data_in_dir) +{ + struct IN2000_hostdata *hostdata; + unsigned short *sp; + unsigned short f; + int i; + + hostdata = (struct IN2000_hostdata *) cmd->device->host->hostdata; + +/* 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 (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) { + ++cmd->SCp.buffer; + --cmd->SCp.buffers_residual; + cmd->SCp.this_residual = cmd->SCp.buffer->length; + cmd->SCp.ptr = page_address(cmd->SCp.buffer->page) + cmd->SCp.buffer->offset; + } + +/* Set up hardware registers */ + + write_3393(hostdata, WD_SYNCHRONOUS_TRANSFER, hostdata->sync_xfer[cmd->device->id]); + write_3393_count(hostdata, cmd->SCp.this_residual); + write_3393(hostdata, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_BUS); + write1_io(0, IO_FIFO_WRITE); /* zero counter, assume write */ + +/* Reading is easy. Just issue the command and return - we'll + * get an interrupt later when we have actual data to worry about. + */ + + if (data_in_dir) { + write1_io(0, IO_FIFO_READ); + if ((hostdata->level2 >= L2_DATA) || (hostdata->level2 == L2_BASIC && cmd->SCp.phase == 0)) { + write_3393(hostdata, WD_COMMAND_PHASE, 0x45); + write_3393_cmd(hostdata, WD_CMD_SEL_ATN_XFER); + hostdata->state = S_RUNNING_LEVEL2; + } else + write_3393_cmd(hostdata, WD_CMD_TRANS_INFO); + hostdata->fifo = FI_FIFO_READING; + cmd->SCp.have_data_in = 0; + return; + } + +/* Writing is more involved - we'll start the WD chip and write as + * much data to the fifo as we can right now. Later interrupts will + * write any bytes that don't make it at this stage. + */ + + if ((hostdata->level2 >= L2_DATA) || (hostdata->level2 == L2_BASIC && cmd->SCp.phase == 0)) { + write_3393(hostdata, WD_COMMAND_PHASE, 0x45); + write_3393_cmd(hostdata, WD_CMD_SEL_ATN_XFER); + hostdata->state = S_RUNNING_LEVEL2; + } else + write_3393_cmd(hostdata, WD_CMD_TRANS_INFO); + hostdata->fifo = FI_FIFO_WRITING; + sp = (unsigned short *) cmd->SCp.ptr; + + if ((i = cmd->SCp.this_residual) > IN2000_FIFO_SIZE) + i = IN2000_FIFO_SIZE; + cmd->SCp.have_data_in = i; + i >>= 1; /* Gulp. We assume this_residual is modulo 2 */ + f = hostdata->io_base + IO_FIFO; + +#ifdef FAST_WRITE_IO + + FAST_WRITE2_IO(); +#else + while (i--) + write2_io(*sp++, IO_FIFO); + +#endif + +} + + +/* We need to use spin_lock_irqsave() & spin_unlock_irqrestore() in this + * function in order to work in an SMP environment. (I'd be surprised + * if the driver is ever used by anyone on a real multi-CPU motherboard, + * but it _does_ need to be able to compile and run in an SMP kernel.) + */ + +static irqreturn_t in2000_intr(int irqnum, void *dev_id, struct pt_regs *ptregs) +{ + struct Scsi_Host *instance = dev_id; + struct IN2000_hostdata *hostdata; + Scsi_Cmnd *patch, *cmd; + uchar asr, sr, phs, id, lun, *ucp, msg; + int i, j; + unsigned long length; + unsigned short *sp; + unsigned short f; + unsigned long flags; + + hostdata = (struct IN2000_hostdata *) instance->hostdata; + +/* Get the spin_lock and disable further ints, for SMP */ + + spin_lock_irqsave(instance->host_lock, flags); + +#ifdef PROC_STATISTICS + hostdata->int_cnt++; +#endif + +/* The IN2000 card has 2 interrupt sources OR'ed onto its IRQ line - the + * WD3393 chip and the 2k fifo (which is actually a dual-port RAM combined + * with a big logic array, so it's a little different than what you might + * expect). As far as I know, there's no reason that BOTH can't be active + * at the same time, but there's a problem: while we can read the 3393 + * to tell if _it_ wants an interrupt, I don't know of a way to ask the + * fifo the same question. The best we can do is check the 3393 and if + * it _isn't_ the source of the interrupt, then we can be pretty sure + * that the fifo is the culprit. + * UPDATE: I have it on good authority (Bill Earnest) that bit 0 of the + * IO_FIFO_COUNT register mirrors the fifo interrupt state. I + * assume that bit clear means interrupt active. As it turns + * out, the driver really doesn't need to check for this after + * all, so my remarks above about a 'problem' can safely be + * ignored. The way the logic is set up, there's no advantage + * (that I can see) to worrying about it. + * + * It seems that the fifo interrupt signal is negated when we extract + * bytes during read or write bytes during write. + * - fifo will interrupt when data is moving from it to the 3393, and + * there are 31 (or less?) bytes left to go. This is sort of short- + * sighted: what if you don't WANT to do more? In any case, our + * response is to push more into the fifo - either actual data or + * dummy bytes if need be. Note that we apparently have to write at + * least 32 additional bytes to the fifo after an interrupt in order + * to get it to release the ones it was holding on to - writing fewer + * than 32 will result in another fifo int. + * UPDATE: Again, info from Bill Earnest makes this more understandable: + * 32 bytes = two counts of the fifo counter register. He tells + * me that the fifo interrupt is a non-latching signal derived + * from a straightforward boolean interpretation of the 7 + * highest bits of the fifo counter and the fifo-read/fifo-write + * state. Who'd a thought? + */ + + write1_io(0, IO_LED_ON); + asr = READ_AUX_STAT(); + if (!(asr & ASR_INT)) { /* no WD33c93 interrupt? */ + +/* Ok. This is definitely a FIFO-only interrupt. + * + * If FI_FIFO_READING is set, there are up to 2048 bytes waiting to be read, + * maybe more to come from the SCSI bus. Read as many as we can out of the + * fifo and into memory at the location of SCp.ptr[SCp.have_data_in], and + * update have_data_in afterwards. + * + * If we have FI_FIFO_WRITING, the FIFO has almost run out of bytes to move + * into the WD3393 chip (I think the interrupt happens when there are 31 + * bytes left, but it may be fewer...). The 3393 is still waiting, so we + * shove some more into the fifo, which gets things moving again. If the + * original SCSI command specified more than 2048 bytes, there may still + * be some of that data left: fine - use it (from SCp.ptr[SCp.have_data_in]). + * Don't forget to update have_data_in. If we've already written out the + * entire buffer, feed 32 dummy bytes to the fifo - they're needed to + * push out the remaining real data. + * (Big thanks to Bill Earnest for getting me out of the mud in here.) + */ + + cmd = (Scsi_Cmnd *) hostdata->connected; /* assume we're connected */ + CHECK_NULL(cmd, "fifo_int") + + if (hostdata->fifo == FI_FIFO_READING) { + + DB(DB_FIFO, printk("{R:%02x} ", read1_io(IO_FIFO_COUNT))) + + sp = (unsigned short *) (cmd->SCp.ptr + cmd->SCp.have_data_in); + i = read1_io(IO_FIFO_COUNT) & 0xfe; + i <<= 2; /* # of words waiting in the fifo */ + f = hostdata->io_base + IO_FIFO; + +#ifdef FAST_READ_IO + + FAST_READ2_IO(); +#else + while (i--) + *sp++ = read2_io(IO_FIFO); + +#endif + + i = sp - (unsigned short *) (cmd->SCp.ptr + cmd->SCp.have_data_in); + i <<= 1; + cmd->SCp.have_data_in += i; + } + + else if (hostdata->fifo == FI_FIFO_WRITING) { + + DB(DB_FIFO, printk("{W:%02x} ", read1_io(IO_FIFO_COUNT))) + +/* If all bytes have been written to the fifo, flush out the stragglers. + * Note that while writing 16 dummy words seems arbitrary, we don't + * have another choice that I can see. What we really want is to read + * the 3393 transfer count register (that would tell us how many bytes + * needed flushing), but the TRANSFER_INFO command hasn't completed + * yet (not enough bytes!) and that register won't be accessible. So, + * we use 16 words - a number obtained through trial and error. + * UPDATE: Bill says this is exactly what Always does, so there. + * More thanks due him for help in this section. + */ + if (cmd->SCp.this_residual == cmd->SCp.have_data_in) { + i = 16; + while (i--) /* write 32 dummy bytes */ + write2_io(0, IO_FIFO); + } + +/* If there are still bytes left in the SCSI buffer, write as many as we + * can out to the fifo. + */ + + else { + sp = (unsigned short *) (cmd->SCp.ptr + cmd->SCp.have_data_in); + i = cmd->SCp.this_residual - cmd->SCp.have_data_in; /* bytes yet to go */ + j = read1_io(IO_FIFO_COUNT) & 0xfe; + j <<= 2; /* how many words the fifo has room for */ + if ((j << 1) > i) + j = (i >> 1); + while (j--) + write2_io(*sp++, IO_FIFO); + + i = sp - (unsigned short *) (cmd->SCp.ptr + cmd->SCp.have_data_in); + i <<= 1; + cmd->SCp.have_data_in += i; + } + } + + else { + printk("*** Spurious FIFO interrupt ***"); + } + + write1_io(0, IO_LED_OFF); + +/* release the SMP spin_lock and restore irq state */ + spin_unlock_irqrestore(instance->host_lock, flags); + return IRQ_HANDLED; + } + +/* This interrupt was triggered by the WD33c93 chip. The fifo interrupt + * may also be asserted, but we don't bother to check it: we get more + * detailed info from FIFO_READING and FIFO_WRITING (see below). + */ + + cmd = (Scsi_Cmnd *) hostdata->connected; /* assume we're connected */ + sr = read_3393(hostdata, WD_SCSI_STATUS); /* clear the interrupt */ + phs = read_3393(hostdata, WD_COMMAND_PHASE); + + if (!cmd && (sr != CSR_RESEL_AM && sr != CSR_TIMEOUT && sr != CSR_SELECT)) { + printk("\nNR:wd-intr-1\n"); + write1_io(0, IO_LED_OFF); + +/* release the SMP spin_lock and restore irq state */ + spin_unlock_irqrestore(instance->host_lock, flags); + return IRQ_HANDLED; + } + + DB(DB_INTR, printk("{%02x:%02x-", asr, sr)) + +/* After starting a FIFO-based transfer, the next _WD3393_ interrupt is + * guaranteed to be in response to the completion of the transfer. + * If we were reading, there's probably data in the fifo that needs + * to be copied into RAM - do that here. 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 necessary with the fifo, we go on and + * |