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seagate.c
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seagate.c
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/*
* seagate.c Copyright (C) 1992, 1993 Drew Eckhardt
* low level scsi driver for ST01/ST02, Future Domain TMC-885,
* TMC-950 by Drew Eckhardt <drew@colorado.edu>
*
* Note : TMC-880 boards don't work because they have two bits in
* the status register flipped, I'll fix this "RSN"
* [why do I have strong feeling that above message is from 1993? :-)
* pavel@ucw.cz]
*
* This card does all the I/O via memory mapped I/O, so there is no need
* to check or allocate a region of the I/O address space.
*/
/* 1996 - to use new read{b,w,l}, write{b,w,l}, and phys_to_virt
* macros, replaced assembler routines with C. There's probably a
* performance hit, but I only have a cdrom and can't tell. Define
* SEAGATE_USE_ASM if you want the old assembler code -- SJT
*
* 1998-jul-29 - created DPRINTK macros and made it work under
* linux 2.1.112, simplified some #defines etc. <pavel@ucw.cz>
*
* Aug 2000 - aeb - deleted seagate_st0x_biosparam(). It would try to
* read the physical disk geometry, a bad mistake. Of course it doesn't
* matter much what geometry one invents, but on large disks it
* returned 256 (or more) heads, causing all kind of failures.
* Of course this means that people might see a different geometry now,
* so boot parameters may be necessary in some cases.
*/
/*
* Configuration :
* To use without BIOS -DOVERRIDE=base_address -DCONTROLLER=FD or SEAGATE
* -DIRQ will override the default of 5.
* Note: You can now set these options from the kernel's "command line".
* The syntax is:
*
* st0x=ADDRESS,IRQ (for a Seagate controller)
* or:
* tmc8xx=ADDRESS,IRQ (for a TMC-8xx or TMC-950 controller)
* eg:
* tmc8xx=0xC8000,15
*
* will configure the driver for a TMC-8xx style controller using IRQ 15
* with a base address of 0xC8000.
*
* -DARBITRATE
* Will cause the host adapter to arbitrate for the
* bus for better SCSI-II compatibility, rather than just
* waiting for BUS FREE and then doing its thing. Should
* let us do one command per Lun when I integrate my
* reorganization changes into the distribution sources.
*
* -DDEBUG=65535
* Will activate debug code.
*
* -DFAST or -DFAST32
* Will use blind transfers where possible
*
* -DPARITY
* This will enable parity.
*
* -DSEAGATE_USE_ASM
* Will use older seagate assembly code. should be (very small amount)
* Faster.
*
* -DSLOW_RATE=50
* Will allow compatibility with broken devices that don't
* handshake fast enough (ie, some CD ROM's) for the Seagate
* code.
*
* 50 is some number, It will let you specify a default
* transfer rate if handshaking isn't working correctly.
*
* -DOLDCNTDATASCEME There is a new sceme to set the CONTROL
* and DATA reigsters which complies more closely
* with the SCSI2 standard. This hopefully eliminates
* the need to swap the order these registers are
* 'messed' with. It makes the following two options
* obsolete. To reenable the old sceme define this.
*
* The following to options are patches from the SCSI.HOWTO
*
* -DSWAPSTAT This will swap the definitions for STAT_MSG and STAT_CD.
*
* -DSWAPCNTDATA This will swap the order that seagate.c messes with
* the CONTROL an DATA registers.
*/
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/signal.h>
#include <linux/string.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/stat.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_host.h>
#ifdef DEBUG
#define DPRINTK( when, msg... ) do { if ( (DEBUG & (when)) == (when) ) printk( msg ); } while (0)
#else
#define DPRINTK( when, msg... ) do { } while (0)
#endif
#define DANY( msg... ) DPRINTK( 0xffff, msg );
#ifndef IRQ
#define IRQ 5
#endif
#ifdef FAST32
#define FAST
#endif
#undef LINKED /* Linked commands are currently broken! */
#if defined(OVERRIDE) && !defined(CONTROLLER)
#error Please use -DCONTROLLER=SEAGATE or -DCONTROLLER=FD to override controller type
#endif
#ifndef __i386__
#undef SEAGATE_USE_ASM
#endif
/*
Thanks to Brian Antoine for the example code in his Messy-Loss ST-01
driver, and Mitsugu Suzuki for information on the ST-01
SCSI host.
*/
/*
CONTROL defines
*/
#define CMD_RST 0x01
#define CMD_SEL 0x02
#define CMD_BSY 0x04
#define CMD_ATTN 0x08
#define CMD_START_ARB 0x10
#define CMD_EN_PARITY 0x20
#define CMD_INTR 0x40
#define CMD_DRVR_ENABLE 0x80
/*
STATUS
*/
#ifdef SWAPSTAT
#define STAT_MSG 0x08
#define STAT_CD 0x02
#else
#define STAT_MSG 0x02
#define STAT_CD 0x08
#endif
#define STAT_BSY 0x01
#define STAT_IO 0x04
#define STAT_REQ 0x10
#define STAT_SEL 0x20
#define STAT_PARITY 0x40
#define STAT_ARB_CMPL 0x80
/*
REQUESTS
*/
#define REQ_MASK (STAT_CD | STAT_IO | STAT_MSG)
#define REQ_DATAOUT 0
#define REQ_DATAIN STAT_IO
#define REQ_CMDOUT STAT_CD
#define REQ_STATIN (STAT_CD | STAT_IO)
#define REQ_MSGOUT (STAT_MSG | STAT_CD)
#define REQ_MSGIN (STAT_MSG | STAT_CD | STAT_IO)
extern volatile int seagate_st0x_timeout;
#ifdef PARITY
#define BASE_CMD CMD_EN_PARITY
#else
#define BASE_CMD 0
#endif
/*
Debugging code
*/
#define PHASE_BUS_FREE 1
#define PHASE_ARBITRATION 2
#define PHASE_SELECTION 4
#define PHASE_DATAIN 8
#define PHASE_DATAOUT 0x10
#define PHASE_CMDOUT 0x20
#define PHASE_MSGIN 0x40
#define PHASE_MSGOUT 0x80
#define PHASE_STATUSIN 0x100
#define PHASE_ETC (PHASE_DATAIN | PHASE_DATAOUT | PHASE_CMDOUT | PHASE_MSGIN | PHASE_MSGOUT | PHASE_STATUSIN)
#define PRINT_COMMAND 0x200
#define PHASE_EXIT 0x400
#define PHASE_RESELECT 0x800
#define DEBUG_FAST 0x1000
#define DEBUG_SG 0x2000
#define DEBUG_LINKED 0x4000
#define DEBUG_BORKEN 0x8000
/*
* Control options - these are timeouts specified in .01 seconds.
*/
/* 30, 20 work */
#define ST0X_BUS_FREE_DELAY 25
#define ST0X_SELECTION_DELAY 25
#define SEAGATE 1 /* these determine the type of the controller */
#define FD 2
#define ST0X_ID_STR "Seagate ST-01/ST-02"
#define FD_ID_STR "TMC-8XX/TMC-950"
static int internal_command (unsigned char target, unsigned char lun,
const void *cmnd,
void *buff, int bufflen, int reselect);
static int incommand; /* set if arbitration has finished
and we are in some command phase. */
static unsigned int base_address = 0; /* Where the card ROM starts, used to
calculate memory mapped register
location. */
static void __iomem *st0x_cr_sr; /* control register write, status
register read. 256 bytes in
length.
Read is status of SCSI BUS, as per
STAT masks. */
static void __iomem *st0x_dr; /* data register, read write 256
bytes in length. */
static volatile int st0x_aborted = 0; /* set when we are aborted, ie by a
time out, etc. */
static unsigned char controller_type = 0; /* set to SEAGATE for ST0x
boards or FD for TMC-8xx
boards */
static int irq = IRQ;
module_param(base_address, uint, 0);
module_param(controller_type, byte, 0);
module_param(irq, int, 0);
MODULE_LICENSE("GPL");
#define retcode(result) (((result) << 16) | (message << 8) | status)
#define STATUS ((u8) readb(st0x_cr_sr))
#define DATA ((u8) readb(st0x_dr))
#define WRITE_CONTROL(d) { writeb((d), st0x_cr_sr); }
#define WRITE_DATA(d) { writeb((d), st0x_dr); }
#ifndef OVERRIDE
static unsigned int seagate_bases[] = {
0xc8000, 0xca000, 0xcc000,
0xce000, 0xdc000, 0xde000
};
typedef struct {
const unsigned char *signature;
unsigned offset;
unsigned length;
unsigned char type;
} Signature;
static Signature __initdata signatures[] = {
{"ST01 v1.7 (C) Copyright 1987 Seagate", 15, 37, SEAGATE},
{"SCSI BIOS 2.00 (C) Copyright 1987 Seagate", 15, 40, SEAGATE},
/*
* The following two lines are NOT mistakes. One detects ROM revision
* 3.0.0, the other 3.2. Since seagate has only one type of SCSI adapter,
* and this is not going to change, the "SEAGATE" and "SCSI" together
* are probably "good enough"
*/
{"SEAGATE SCSI BIOS ", 16, 17, SEAGATE},
{"SEAGATE SCSI BIOS ", 17, 17, SEAGATE},
/*
* However, future domain makes several incompatible SCSI boards, so specific
* signatures must be used.
*/
{"FUTURE DOMAIN CORP. (C) 1986-1989 V5.0C2/14/89", 5, 46, FD},
{"FUTURE DOMAIN CORP. (C) 1986-1989 V6.0A7/28/89", 5, 46, FD},
{"FUTURE DOMAIN CORP. (C) 1986-1990 V6.0105/31/90", 5, 47, FD},
{"FUTURE DOMAIN CORP. (C) 1986-1990 V6.0209/18/90", 5, 47, FD},
{"FUTURE DOMAIN CORP. (C) 1986-1990 V7.009/18/90", 5, 46, FD},
{"FUTURE DOMAIN CORP. (C) 1992 V8.00.004/02/92", 5, 44, FD},
{"IBM F1 BIOS V1.1004/30/92", 5, 25, FD},
{"FUTURE DOMAIN TMC-950", 5, 21, FD},
/* Added for 2.2.16 by Matthias_Heidbrink@b.maus.de */
{"IBM F1 V1.2009/22/93", 5, 25, FD},
};
#define NUM_SIGNATURES ARRAY_SIZE(signatures)
#endif /* n OVERRIDE */
/*
* hostno stores the hostnumber, as told to us by the init routine.
*/
static int hostno = -1;
static void seagate_reconnect_intr (int, void *);
static irqreturn_t do_seagate_reconnect_intr (int, void *);
static int seagate_st0x_bus_reset(struct scsi_cmnd *);
#ifdef FAST
static int fast = 1;
#else
#define fast 0
#endif
#ifdef SLOW_RATE
/*
* Support for broken devices :
* The Seagate board has a handshaking problem. Namely, a lack
* thereof for slow devices. You can blast 600K/second through
* it if you are polling for each byte, more if you do a blind
* transfer. In the first case, with a fast device, REQ will
* transition high-low or high-low-high before your loop restarts
* and you'll have no problems. In the second case, the board
* will insert wait states for up to 13.2 usecs for REQ to
* transition low->high, and everything will work.
*
* However, there's nothing in the state machine that says
* you *HAVE* to see a high-low-high set of transitions before
* sending the next byte, and slow things like the Trantor CD ROMS
* will break because of this.
*
* So, we need to slow things down, which isn't as simple as it
* seems. We can't slow things down period, because then people
* who don't recompile their kernels will shoot me for ruining
* their performance. We need to do it on a case per case basis.
*
* The best for performance will be to, only for borken devices
* (this is stored on a per-target basis in the scsi_devices array)
*
* Wait for a low->high transition before continuing with that
* transfer. If we timeout, continue anyways. We don't need
* a long timeout, because REQ should only be asserted until the
* corresponding ACK is received and processed.
*
* Note that we can't use the system timer for this, because of
* resolution, and we *really* can't use the timer chip since
* gettimeofday() and the beeper routines use that. So,
* the best thing for us to do will be to calibrate a timing
* loop in the initialization code using the timer chip before
* gettimeofday() can screw with it.
*
* FIXME: this is broken (not borken :-). Empty loop costs less than
* loop with ISA access in it! -- pavel@ucw.cz
*/
static int borken_calibration = 0;
static void __init borken_init (void)
{
register int count = 0, start = jiffies + 1, stop = start + 25;
/* FIXME: There may be a better approach, this is a straight port for
now */
preempt_disable();
while (time_before (jiffies, start))
cpu_relax();
for (; time_before (jiffies, stop); ++count)
cpu_relax();
preempt_enable();
/*
* Ok, we now have a count for .25 seconds. Convert to a
* count per second and divide by transfer rate in K. */
borken_calibration = (count * 4) / (SLOW_RATE * 1024);
if (borken_calibration < 1)
borken_calibration = 1;
}
static inline void borken_wait (void)
{
register int count;
for (count = borken_calibration; count && (STATUS & STAT_REQ); --count)
cpu_relax();
#if (DEBUG & DEBUG_BORKEN)
if (count)
printk ("scsi%d : borken timeout\n", hostno);
#endif
}
#endif /* def SLOW_RATE */
/* These beasts only live on ISA, and ISA means 8MHz. Each ULOOP()
* contains at least one ISA access, which takes more than 0.125
* usec. So if we loop 8 times time in usec, we are safe.
*/
#define ULOOP( i ) for (clock = i*8;;)
#define TIMEOUT (!(clock--))
int __init seagate_st0x_detect (struct scsi_host_template * tpnt)
{
struct Scsi_Host *instance;
int i, j;
unsigned long cr, dr;
tpnt->proc_name = "seagate";
/*
* First, we try for the manual override.
*/
DANY ("Autodetecting ST0x / TMC-8xx\n");
if (hostno != -1) {
printk (KERN_ERR "seagate_st0x_detect() called twice?!\n");
return 0;
}
/* If the user specified the controller type from the command line,
controller_type will be non-zero, so don't try to detect one */
if (!controller_type) {
#ifdef OVERRIDE
base_address = OVERRIDE;
controller_type = CONTROLLER;
DANY ("Base address overridden to %x, controller type is %s\n",
base_address,
controller_type == SEAGATE ? "SEAGATE" : "FD");
#else /* OVERRIDE */
/*
* To detect this card, we simply look for the signature
* from the BIOS version notice in all the possible locations
* of the ROM's. This has a nice side effect of not trashing
* any register locations that might be used by something else.
*
* XXX - note that we probably should be probing the address
* space for the on-board RAM instead.
*/
for (i = 0; i < ARRAY_SIZE(seagate_bases); ++i) {
void __iomem *p = ioremap(seagate_bases[i], 0x2000);
if (!p)
continue;
for (j = 0; j < NUM_SIGNATURES; ++j)
if (check_signature(p + signatures[j].offset, signatures[j].signature, signatures[j].length)) {
base_address = seagate_bases[i];
controller_type = signatures[j].type;
break;
}
iounmap(p);
}
#endif /* OVERRIDE */
}
/* (! controller_type) */
tpnt->this_id = (controller_type == SEAGATE) ? 7 : 6;
tpnt->name = (controller_type == SEAGATE) ? ST0X_ID_STR : FD_ID_STR;
if (!base_address) {
printk(KERN_INFO "seagate: ST0x/TMC-8xx not detected.\n");
return 0;
}
cr = base_address + (controller_type == SEAGATE ? 0x1a00 : 0x1c00);
dr = cr + 0x200;
st0x_cr_sr = ioremap(cr, 0x100);
st0x_dr = ioremap(dr, 0x100);
DANY("%s detected. Base address = %x, cr = %x, dr = %x\n",
tpnt->name, base_address, cr, dr);
/*
* At all times, we will use IRQ 5. Should also check for IRQ3
* if we lose our first interrupt.
*/
instance = scsi_register (tpnt, 0);
if (instance == NULL)
return 0;
hostno = instance->host_no;
if (request_irq (irq, do_seagate_reconnect_intr, IRQF_DISABLED, (controller_type == SEAGATE) ? "seagate" : "tmc-8xx", instance)) {
printk(KERN_ERR "scsi%d : unable to allocate IRQ%d\n", hostno, irq);
return 0;
}
instance->irq = irq;
instance->io_port = base_address;
#ifdef SLOW_RATE
printk(KERN_INFO "Calibrating borken timer... ");
borken_init();
printk(" %d cycles per transfer\n", borken_calibration);
#endif
printk (KERN_INFO "This is one second... ");
{
int clock;
ULOOP (1 * 1000 * 1000) {
STATUS;
if (TIMEOUT)
break;
}
}
printk ("done, %s options:"
#ifdef ARBITRATE
" ARBITRATE"
#endif
#ifdef DEBUG
" DEBUG"
#endif
#ifdef FAST
" FAST"
#ifdef FAST32
"32"
#endif
#endif
#ifdef LINKED
" LINKED"
#endif
#ifdef PARITY
" PARITY"
#endif
#ifdef SEAGATE_USE_ASM
" SEAGATE_USE_ASM"
#endif
#ifdef SLOW_RATE
" SLOW_RATE"
#endif
#ifdef SWAPSTAT
" SWAPSTAT"
#endif
#ifdef SWAPCNTDATA
" SWAPCNTDATA"
#endif
"\n", tpnt->name);
return 1;
}
static const char *seagate_st0x_info (struct Scsi_Host *shpnt)
{
static char buffer[64];
snprintf(buffer, 64, "%s at irq %d, address 0x%05X",
(controller_type == SEAGATE) ? ST0X_ID_STR : FD_ID_STR,
irq, base_address);
return buffer;
}
/*
* These are our saved pointers for the outstanding command that is
* waiting for a reconnect
*/
static unsigned char current_target, current_lun;
static unsigned char *current_cmnd, *current_data;
static int current_nobuffs;
static struct scatterlist *current_buffer;
static int current_bufflen;
#ifdef LINKED
/*
* linked_connected indicates whether or not we are currently connected to
* linked_target, linked_lun and in an INFORMATION TRANSFER phase,
* using linked commands.
*/
static int linked_connected = 0;
static unsigned char linked_target, linked_lun;
#endif
static void (*done_fn) (struct scsi_cmnd *) = NULL;
static struct scsi_cmnd *SCint = NULL;
/*
* These control whether or not disconnect / reconnect will be attempted,
* or are being attempted.
*/
#define NO_RECONNECT 0
#define RECONNECT_NOW 1
#define CAN_RECONNECT 2
/*
* LINKED_RIGHT indicates that we are currently connected to the correct target
* for this command, LINKED_WRONG indicates that we are connected to the wrong
* target. Note that these imply CAN_RECONNECT and require defined(LINKED).
*/
#define LINKED_RIGHT 3
#define LINKED_WRONG 4
/*
* This determines if we are expecting to reconnect or not.
*/
static int should_reconnect = 0;
/*
* The seagate_reconnect_intr routine is called when a target reselects the
* host adapter. This occurs on the interrupt triggered by the target
* asserting SEL.
*/
static irqreturn_t do_seagate_reconnect_intr(int irq, void *dev_id)
{
unsigned long flags;
struct Scsi_Host *dev = dev_id;
spin_lock_irqsave (dev->host_lock, flags);
seagate_reconnect_intr (irq, dev_id);
spin_unlock_irqrestore (dev->host_lock, flags);
return IRQ_HANDLED;
}
static void seagate_reconnect_intr (int irq, void *dev_id)
{
int temp;
struct scsi_cmnd *SCtmp;
DPRINTK (PHASE_RESELECT, "scsi%d : seagate_reconnect_intr() called\n", hostno);
if (!should_reconnect)
printk(KERN_WARNING "scsi%d: unexpected interrupt.\n", hostno);
else {
should_reconnect = 0;
DPRINTK (PHASE_RESELECT, "scsi%d : internal_command(%d, %08x, %08x, RECONNECT_NOW\n",
hostno, current_target, current_data, current_bufflen);
temp = internal_command (current_target, current_lun, current_cmnd, current_data, current_bufflen, RECONNECT_NOW);
if (msg_byte(temp) != DISCONNECT) {
if (done_fn) {
DPRINTK(PHASE_RESELECT, "scsi%d : done_fn(%d,%08x)", hostno, hostno, temp);
if (!SCint)
panic ("SCint == NULL in seagate");
SCtmp = SCint;
SCint = NULL;
SCtmp->result = temp;
done_fn(SCtmp);
} else
printk(KERN_ERR "done_fn() not defined.\n");
}
}
}
/*
* The seagate_st0x_queue_command() function provides a queued interface
* to the seagate SCSI driver. Basically, it just passes control onto the
* seagate_command() function, after fixing it so that the done_fn()
* is set to the one passed to the function. We have to be very careful,
* because there are some commands on some devices that do not disconnect,
* and if we simply call the done_fn when the command is done then another
* command is started and queue_command is called again... We end up
* overflowing the kernel stack, and this tends not to be such a good idea.
*/
static int recursion_depth = 0;
static int seagate_st0x_queue_command(struct scsi_cmnd * SCpnt,
void (*done) (struct scsi_cmnd *))
{
int result, reconnect;
struct scsi_cmnd *SCtmp;
DANY ("seagate: que_command");
done_fn = done;
current_target = SCpnt->device->id;
current_lun = SCpnt->device->lun;
current_cmnd = SCpnt->cmnd;
current_data = (unsigned char *) SCpnt->request_buffer;
current_bufflen = SCpnt->request_bufflen;
SCint = SCpnt;
if (recursion_depth)
return 1;
recursion_depth++;
do {
#ifdef LINKED
/*
* Set linked command bit in control field of SCSI command.
*/
current_cmnd[SCpnt->cmd_len] |= 0x01;
if (linked_connected) {
DPRINTK (DEBUG_LINKED, "scsi%d : using linked commands, current I_T_L nexus is ", hostno);
if (linked_target == current_target && linked_lun == current_lun)
{
DPRINTK(DEBUG_LINKED, "correct\n");
reconnect = LINKED_RIGHT;
} else {
DPRINTK(DEBUG_LINKED, "incorrect\n");
reconnect = LINKED_WRONG;
}
} else
#endif /* LINKED */
reconnect = CAN_RECONNECT;
result = internal_command(SCint->device->id, SCint->device->lun, SCint->cmnd,
SCint->request_buffer, SCint->request_bufflen, reconnect);
if (msg_byte(result) == DISCONNECT)
break;
SCtmp = SCint;
SCint = NULL;
SCtmp->result = result;
done_fn(SCtmp);
}
while (SCint);
recursion_depth--;
return 0;
}
static int internal_command (unsigned char target, unsigned char lun,
const void *cmnd, void *buff, int bufflen, int reselect)
{
unsigned char *data = NULL;
struct scatterlist *buffer = NULL;
int clock, temp, nobuffs = 0, done = 0, len = 0;
#ifdef DEBUG
int transfered = 0, phase = 0, newphase;
#endif
register unsigned char status_read;
unsigned char tmp_data, tmp_control, status = 0, message = 0;
unsigned transfersize = 0, underflow = 0;
#ifdef SLOW_RATE
int borken = (int) SCint->device->borken; /* Does the current target require
Very Slow I/O ? */
#endif
incommand = 0;
st0x_aborted = 0;
#if (DEBUG & PRINT_COMMAND)
printk("scsi%d : target = %d, command = ", hostno, target);
__scsi_print_command((unsigned char *) cmnd);
#endif
#if (DEBUG & PHASE_RESELECT)
switch (reselect) {
case RECONNECT_NOW:
printk("scsi%d : reconnecting\n", hostno);
break;
#ifdef LINKED
case LINKED_RIGHT:
printk("scsi%d : connected, can reconnect\n", hostno);
break;
case LINKED_WRONG:
printk("scsi%d : connected to wrong target, can reconnect\n",
hostno);
break;
#endif
case CAN_RECONNECT:
printk("scsi%d : allowed to reconnect\n", hostno);
break;
default:
printk("scsi%d : not allowed to reconnect\n", hostno);
}
#endif
if (target == (controller_type == SEAGATE ? 7 : 6))
return DID_BAD_TARGET;
/*
* We work it differently depending on if this is is "the first time,"
* or a reconnect. If this is a reselect phase, then SEL will
* be asserted, and we must skip selection / arbitration phases.
*/
switch (reselect) {
case RECONNECT_NOW:
DPRINTK (PHASE_RESELECT, "scsi%d : phase RESELECT \n", hostno);
/*
* At this point, we should find the logical or of our ID
* and the original target's ID on the BUS, with BSY, SEL,
* and I/O signals asserted.
*
* After ARBITRATION phase is completed, only SEL, BSY,
* and the target ID are asserted. A valid initiator ID
* is not on the bus until IO is asserted, so we must wait
* for that.
*/
ULOOP (100 * 1000) {
temp = STATUS;
if ((temp & STAT_IO) && !(temp & STAT_BSY))
break;
if (TIMEOUT) {
DPRINTK (PHASE_RESELECT, "scsi%d : RESELECT timed out while waiting for IO .\n", hostno);
return (DID_BAD_INTR << 16);
}
}
/*
* After I/O is asserted by the target, we can read our ID
* and its ID off of the BUS.
*/
if (!((temp = DATA) & (controller_type == SEAGATE ? 0x80 : 0x40))) {
DPRINTK (PHASE_RESELECT, "scsi%d : detected reconnect request to different target.\n\tData bus = %d\n", hostno, temp);
return (DID_BAD_INTR << 16);
}
if (!(temp & (1 << current_target))) {
printk(KERN_WARNING "scsi%d : Unexpected reselect interrupt. Data bus = %d\n", hostno, temp);
return (DID_BAD_INTR << 16);
}
buffer = current_buffer;
cmnd = current_cmnd; /* WDE add */
data = current_data; /* WDE add */
len = current_bufflen; /* WDE add */
nobuffs = current_nobuffs;
/*
* We have determined that we have been selected. At this
* point, we must respond to the reselection by asserting
* BSY ourselves
*/
#if 1
WRITE_CONTROL (BASE_CMD | CMD_DRVR_ENABLE | CMD_BSY);
#else
WRITE_CONTROL (BASE_CMD | CMD_BSY);
#endif
/*
* The target will drop SEL, and raise BSY, at which time
* we must drop BSY.
*/
ULOOP (100 * 1000) {
if (!(STATUS & STAT_SEL))
break;
if (TIMEOUT) {
WRITE_CONTROL (BASE_CMD | CMD_INTR);
DPRINTK (PHASE_RESELECT, "scsi%d : RESELECT timed out while waiting for SEL.\n", hostno);
return (DID_BAD_INTR << 16);
}
}
WRITE_CONTROL (BASE_CMD);
/*
* At this point, we have connected with the target
* and can get on with our lives.
*/
break;
case CAN_RECONNECT:
#ifdef LINKED
/*
* This is a bletcherous hack, just as bad as the Unix #!
* interpreter stuff. If it turns out we are using the wrong
* I_T_L nexus, the easiest way to deal with it is to go into
* our INFORMATION TRANSFER PHASE code, send a ABORT
* message on MESSAGE OUT phase, and then loop back to here.
*/
connect_loop:
#endif
DPRINTK (PHASE_BUS_FREE, "scsi%d : phase = BUS FREE \n", hostno);
/*
* BUS FREE PHASE
*
* On entry, we make sure that the BUS is in a BUS FREE
* phase, by insuring that both BSY and SEL are low for
* at least one bus settle delay. Several reads help
* eliminate wire glitch.
*/
#ifndef ARBITRATE
#error FIXME: this is broken: we may not use jiffies here - we are under cli(). It will hardlock.
clock = jiffies + ST0X_BUS_FREE_DELAY;
while (((STATUS | STATUS | STATUS) & (STAT_BSY | STAT_SEL)) && (!st0x_aborted) && time_before (jiffies, clock))
cpu_relax();
if (time_after (jiffies, clock))
return retcode (DID_BUS_BUSY);
else if (st0x_aborted)
return retcode (st0x_aborted);
#endif
DPRINTK (PHASE_SELECTION, "scsi%d : phase = SELECTION\n", hostno);
clock = jiffies + ST0X_SELECTION_DELAY;
/*
* Arbitration/selection procedure :
* 1. Disable drivers
* 2. Write HOST adapter address bit
* 3. Set start arbitration.
* 4. We get either ARBITRATION COMPLETE or SELECT at this
* point.
* 5. OR our ID and targets on bus.
* 6. Enable SCSI drivers and asserted SEL and ATTN
*/
#ifdef ARBITRATE
/* FIXME: verify host lock is always held here */
WRITE_CONTROL(0);
WRITE_DATA((controller_type == SEAGATE) ? 0x80 : 0x40);
WRITE_CONTROL(CMD_START_ARB);
ULOOP (ST0X_SELECTION_DELAY * 10000) {
status_read = STATUS;
if (status_read & STAT_ARB_CMPL)
break;
if (st0x_aborted) /* FIXME: What? We are going to do something even after abort? */
break;
if (TIMEOUT || (status_read & STAT_SEL)) {
printk(KERN_WARNING "scsi%d : arbitration lost or timeout.\n", hostno);
WRITE_CONTROL (BASE_CMD);
return retcode (DID_NO_CONNECT);
}
}
DPRINTK (PHASE_SELECTION, "scsi%d : arbitration complete\n", hostno);
#endif
/*
* When the SCSI device decides that we're gawking at it,
* it will respond by asserting BUSY on the bus.
*
* Note : the Seagate ST-01/02 product manual says that we
* should twiddle the DATA register before the control
* register. However, this does not work reliably so we do
* it the other way around.
*
* Probably could be a problem with arbitration too, we
* really should try this with a SCSI protocol or logic
* analyzer to see what is going on.
*/
tmp_data = (unsigned char) ((1 << target) | (controller_type == SEAGATE ? 0x80 : 0x40));
tmp_control = BASE_CMD | CMD_DRVR_ENABLE | CMD_SEL | (reselect ? CMD_ATTN : 0);
/* FIXME: verify host lock is always held here */
#ifdef OLDCNTDATASCEME
#ifdef SWAPCNTDATA
WRITE_CONTROL (tmp_control);
WRITE_DATA (tmp_data);
#else
WRITE_DATA (tmp_data);
WRITE_CONTROL (tmp_control);
#endif
#else
tmp_control ^= CMD_BSY; /* This is guesswork. What used to be in driver */
WRITE_CONTROL (tmp_control); /* could never work: it sent data into control */
WRITE_DATA (tmp_data); /* register and control info into data. Hopefully */
tmp_control ^= CMD_BSY; /* fixed, but order of first two may be wrong. */
WRITE_CONTROL (tmp_control); /* -- pavel@ucw.cz */
#endif
ULOOP (250 * 1000) {
if (st0x_aborted) {
/*
* If we have been aborted, and we have a
* command in progress, IE the target
* still has BSY asserted, then we will
* reset the bus, and notify the midlevel
* driver to expect sense.
*/
WRITE_CONTROL (BASE_CMD);
if (STATUS & STAT_BSY) {
printk(KERN_WARNING "scsi%d : BST asserted after we've been aborted.\n", hostno);
seagate_st0x_bus_reset(NULL);
return retcode (DID_RESET);
}
return retcode (st0x_aborted);
}
if (STATUS & STAT_BSY)
break;
if (TIMEOUT) {
DPRINTK (PHASE_SELECTION, "scsi%d : NO CONNECT with target %d, stat = %x \n", hostno, target, STATUS);
return retcode (DID_NO_CONNECT);
}
}
/* Establish current pointers. Take into account scatter / gather */
if ((nobuffs = SCint->use_sg)) {
#if (DEBUG & DEBUG_SG)
{
int i;
printk("scsi%d : scatter gather requested, using %d buffers.\n", hostno, nobuffs);
for (i = 0; i < nobuffs; ++i)
printk("scsi%d : buffer %d address = %p length = %d\n",
hostno, i,