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[SCSI] wd33c93: Fast SCSI with WD33C93B

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Attached are patches, which help to utilize more of the WD33C93B SCSI
controller's capabilities.

1) Added/changed all the necessary code to enable Burst Mode DMA. Only
   Single Byte DMA was used before.

2) Added/changed all the necessary code to enable Fast-10 SCSI transfers.

3) The original driver inadvertently used a transfer period of 1000-800ns
   (the lowest possible transfer rate) for asynchronous data transfers,
   instead of the (configurable) default period intended for this purpose,
   if the target responded to a SDTR not with a Reject-message, but with
   a zero-SDTR. This issue was fixed.
   Moreover, in case of a Reject the driver used the default-period's
   initialization-value instead of its (maybe smaller) current value. The
   missing assignment was added.

4) The driver's commandline- and proc-file-interface was augmented to
   handle the new options properly.

The WD33C93 manual, found at
http://www.datasheet.in/datasheet-html/W/D/3/WD33C93B_WesternDigital.pdf.html,
was very helpful.

Signed-off-by: peter fuerst <post@pfrst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This commit is contained in:
peter fuerst 2007-02-12 15:20:15 +01:00 committed by James Bottomley
parent 7de970e11f
commit a5d8421b2f
2 changed files with 248 additions and 79 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

321
drivers/scsi/wd33c93.c
View File

@ -69,6 +69,11 @@
* 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
*/
#include <linux/module.h>
@ -86,9 +91,11 @@
#include "wd33c93.h"
#define optimum_sx_per(hostdata) (hostdata)->sx_table[1].period_ns
#define WD33C93_VERSION "1.26"
#define WD33C93_DATE "22/Feb/2003"
#define WD33C93_VERSION "1.26++"
#define WD33C93_DATE "10/Feb/2007"
MODULE_AUTHOR("John Shifflett");
MODULE_DESCRIPTION("Generic WD33C93 SCSI driver");
@ -122,6 +129,13 @@ MODULE_LICENSE("GPL");
* 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.
*
@ -148,7 +162,7 @@ MODULE_LICENSE("GPL");
*/
/* Normally, no defaults are specified */
static char *setup_args[] = { "", "", "", "", "", "", "", "", "" };
static char *setup_args[] = { "", "", "", "", "", "", "", "", "", "" };
static char *setup_strings;
module_param(setup_strings, charp, 0);
@ -298,20 +312,8 @@ read_1_byte(const wd33c93_regs regs)
return x;
}
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)
round_period(unsigned int period, const struct sx_period *sx_table)
{
int x;
@ -324,17 +326,49 @@ round_period(unsigned int period)
return 7;
}
/*
* Calculate Synchronous Transfer Register value from SDTR code.
*/
static uchar
calc_sync_xfer(unsigned int period, unsigned int offset)
calc_sync_xfer(unsigned int period, unsigned int offset, unsigned int fast,
const struct 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)].reg_value;
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.
*/
static inline void
calc_sync_msg(unsigned int period, unsigned int offset, unsigned int 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;
}
int
wd33c93_queuecommand(struct scsi_cmnd *cmd,
void (*done)(struct scsi_cmnd *))
@ -632,7 +666,7 @@ wd33c93_execute(struct Scsi_Host *instance)
write_wd33c93_count(regs,
cmd->SCp.this_residual);
write_wd33c93(regs, WD_CONTROL,
CTRL_IDI | CTRL_EDI | CTRL_DMA);
CTRL_IDI | CTRL_EDI | hostdata->dma_mode);
hostdata->dma = D_DMA_RUNNING;
}
} else
@ -712,6 +746,8 @@ transfer_bytes(const wd33c93_regs regs, struct scsi_cmnd *cmd,
cmd->SCp.ptr = page_address(cmd->SCp.buffer->page) +
cmd->SCp.buffer->offset;
}
if (!cmd->SCp.this_residual) /* avoid bogus setups */
return;
write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
hostdata->sync_xfer[cmd->device->id]);
@ -744,7 +780,7 @@ transfer_bytes(const wd33c93_regs regs, struct scsi_cmnd *cmd,
#ifdef PROC_STATISTICS
hostdata->dma_cnt++;
#endif
write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_DMA);
write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | hostdata->dma_mode);
write_wd33c93_count(regs, cmd->SCp.this_residual);
if ((hostdata->level2 >= L2_DATA) ||
@ -862,9 +898,6 @@ wd33c93_intr(struct Scsi_Host *instance)
hostdata->outgoing_msg[0] |= 0x40;
if (hostdata->sync_stat[cmd->device->id] == SS_FIRST) {
#ifdef SYNC_DEBUG
printk(" sending SDTR ");
#endif
hostdata->sync_stat[cmd->device->id] = SS_WAITING;
@ -878,14 +911,20 @@ wd33c93_intr(struct Scsi_Host *instance)
hostdata->outgoing_msg[2] = 3;
hostdata->outgoing_msg[3] = EXTENDED_SDTR;
if (hostdata->no_sync & (1 << cmd->device->id)) {
hostdata->outgoing_msg[4] =
hostdata->default_sx_per / 4;
hostdata->outgoing_msg[5] = 0;
calc_sync_msg(hostdata->default_sx_per, 0,
0, hostdata->outgoing_msg + 4);
} else {
hostdata->outgoing_msg[4] = OPTIMUM_SX_PER / 4;
hostdata->outgoing_msg[5] = OPTIMUM_SX_OFF;
calc_sync_msg(optimum_sx_per(hostdata),
OPTIMUM_SX_OFF,
hostdata->fast,
hostdata->outgoing_msg + 4);
}
hostdata->outgoing_len = 6;
#ifdef SYNC_DEBUG
ucp = hostdata->outgoing_msg + 1;
printk(" sending SDTR %02x03%02x%02x%02x ",
ucp[0], ucp[2], ucp[3], ucp[4]);
#endif
} else
hostdata->outgoing_len = 1;
@ -1001,8 +1040,13 @@ wd33c93_intr(struct Scsi_Host *instance)
#ifdef SYNC_DEBUG
printk("-REJ-");
#endif
if (hostdata->sync_stat[cmd->device->id] == SS_WAITING)
if (hostdata->sync_stat[cmd->device->id] == SS_WAITING) {
hostdata->sync_stat[cmd->device->id] = SS_SET;
/* we want default_sx_per, not DEFAULT_SX_PER */
hostdata->sync_xfer[cmd->device->id] =
calc_sync_xfer(hostdata->default_sx_per
/ 4, 0, 0, hostdata->sx_table);
}
write_wd33c93_cmd(regs, WD_CMD_NEGATE_ACK);
hostdata->state = S_CONNECTED;
break;
@ -1022,7 +1066,10 @@ wd33c93_intr(struct Scsi_Host *instance)
switch (ucp[2]) { /* what's the EXTENDED code? */
case EXTENDED_SDTR:
id = calc_sync_xfer(ucp[3], ucp[4]);
/* 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) {
@ -1041,20 +1088,22 @@ wd33c93_intr(struct Scsi_Host *instance)
hostdata->outgoing_msg[1] = 3;
hostdata->outgoing_msg[2] =
EXTENDED_SDTR;
hostdata->outgoing_msg[3] =
hostdata->default_sx_per /
4;
hostdata->outgoing_msg[4] = 0;
calc_sync_msg(hostdata->
default_sx_per, 0,
0, hostdata->outgoing_msg + 3);
hostdata->outgoing_len = 5;
hostdata->sync_xfer[cmd->device->id] =
calc_sync_xfer(hostdata->
default_sx_per
/ 4, 0);
} else {
hostdata->sync_xfer[cmd->device->id] = id;
if (ucp[4]) /* well, sync transfer */
id = calc_sync_xfer(ucp[3], ucp[4],
hostdata->fast,
hostdata->sx_table);
else if (ucp[3]) /* very unlikely... */
id = calc_sync_xfer(ucp[3], ucp[4],
0, hostdata->sx_table);
}
hostdata->sync_xfer[cmd->device->id] = id;
#ifdef SYNC_DEBUG
printk("sync_xfer=%02x",
printk(" sync_xfer=%02x\n",
hostdata->sync_xfer[cmd->device->id]);
#endif
hostdata->sync_stat[cmd->device->id] =
@ -1486,7 +1535,7 @@ reset_wd33c93(struct Scsi_Host *instance)
write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
write_wd33c93(regs, WD_SYNCHRONOUS_TRANSFER,
calc_sync_xfer(hostdata->default_sx_per / 4,
DEFAULT_SX_OFF));
DEFAULT_SX_OFF, 0, hostdata->sx_table));
write_wd33c93(regs, WD_COMMAND, WD_CMD_RESET);
@ -1512,6 +1561,9 @@ reset_wd33c93(struct Scsi_Host *instance)
} else
hostdata->chip = C_UNKNOWN_CHIP;
if (hostdata->chip != C_WD33C93B) /* Fast SCSI unavailable */
hostdata->fast = 0;
write_wd33c93(regs, WD_TIMEOUT_PERIOD, TIMEOUT_PERIOD_VALUE);
write_wd33c93(regs, WD_CONTROL, CTRL_IDI | CTRL_EDI | CTRL_POLLED);
}
@ -1533,7 +1585,8 @@ wd33c93_host_reset(struct scsi_cmnd * SCpnt)
for (i = 0; i < 8; i++) {
hostdata->busy[i] = 0;
hostdata->sync_xfer[i] =
calc_sync_xfer(DEFAULT_SX_PER / 4, DEFAULT_SX_OFF);
calc_sync_xfer(DEFAULT_SX_PER / 4, DEFAULT_SX_OFF,
0, hostdata->sx_table);
hostdata->sync_stat[i] = SS_UNSET; /* using default sync values */
}
hostdata->input_Q = NULL;
@ -1782,6 +1835,98 @@ check_setup_args(char *key, int *flags, int *val, char *buf)
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 ocurred 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).
*/
static inline unsigned int
round_4(unsigned int x)
{
switch (x & 3) {
case 1: --x;
break;
case 2: ++x;
case 3: ++x;
}
return x;
}
static void
calc_sx_table(unsigned int mhz, struct sx_period sx_table[9])
{
unsigned int d, i;
if (mhz < 11)
d = 2; /* divisor for 8-10 MHz input-clock */
else if (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 */
sx_table[0].period_ns = 1;
sx_table[0].reg_value = 0x20;
for (i = 1; i < 8; i++) {
sx_table[i].period_ns = round_4((i+1)*d / 100);
sx_table[i].reg_value = (i+1)*0x10;
}
sx_table[7].reg_value = 0;
sx_table[8].period_ns = 0;
sx_table[8].reg_value = 0;
}
/*
* 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;
else if (WD33C93_FS_12_15 == freq)
freq = 12;
else if (WD33C93_FS_16_20 == freq)
freq = 16;
else if (freq > 7 && freq < 11)
x = WD33C93_FS_8_10;
else if (freq > 11 && freq < 16)
x = WD33C93_FS_12_15;
else if (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
*/
static inline void 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)
@ -1798,7 +1943,8 @@ wd33c93_init(struct Scsi_Host *instance, const wd33c93_regs regs,
hostdata = (struct WD33C93_hostdata *) instance->hostdata;
hostdata->regs = regs;
hostdata->clock_freq = clock_freq;
hostdata->clock_freq = set_clk_freq(clock_freq, &i);
calc_sx_table(i, hostdata->sx_table);
hostdata->dma_setup = setup;
hostdata->dma_stop = stop;
hostdata->dma_bounce_buffer = NULL;
@ -1806,7 +1952,8 @@ wd33c93_init(struct Scsi_Host *instance, const wd33c93_regs regs,
for (i = 0; i < 8; i++) {
hostdata->busy[i] = 0;
hostdata->sync_xfer[i] =
calc_sync_xfer(DEFAULT_SX_PER / 4, DEFAULT_SX_OFF);
calc_sync_xfer(DEFAULT_SX_PER / 4, DEFAULT_SX_OFF,
0, hostdata->sx_table);
hostdata->sync_stat[i] = SS_UNSET; /* using default sync values */
#ifdef PROC_STATISTICS
hostdata->cmd_cnt[i] = 0;
@ -1828,6 +1975,8 @@ wd33c93_init(struct Scsi_Host *instance, const wd33c93_regs regs,
hostdata->default_sx_per = DEFAULT_SX_PER;
hostdata->no_sync = 0xff; /* sync defaults to off */
hostdata->no_dma = 0; /* default is DMA enabled */
hostdata->fast = 0; /* default is Fast SCSI transfers disabled */
hostdata->dma_mode = CTRL_DMA; /* default is Single Byte DMA */
#ifdef PROC_INTERFACE
hostdata->proc = PR_VERSION | PR_INFO | PR_STATISTICS |
@ -1839,6 +1988,11 @@ wd33c93_init(struct Scsi_Host *instance, const wd33c93_regs regs,
#endif
#endif
if (check_setup_args("clock", &flags, &val, buf)) {
hostdata->clock_freq = set_clk_freq(val, &val);
calc_sx_table(val, hostdata->sx_table);
}
if (check_setup_args("nosync", &flags, &val, buf))
hostdata->no_sync = val;
@ -1847,7 +2001,8 @@ wd33c93_init(struct Scsi_Host *instance, const wd33c93_regs regs,
if (check_setup_args("period", &flags, &val, buf))
hostdata->default_sx_per =
sx_table[round_period((unsigned int) val)].period_ns;
hostdata->sx_table[round_period((unsigned int) val,
hostdata->sx_table)].period_ns;
if (check_setup_args("disconnect", &flags, &val, buf)) {
if ((val >= DIS_NEVER) && (val <= DIS_ALWAYS))
@ -1862,17 +2017,12 @@ wd33c93_init(struct Scsi_Host *instance, const wd33c93_regs regs,
if (check_setup_args("debug", &flags, &val, buf))
hostdata->args = val & DB_MASK;
if (check_setup_args("clock", &flags, &val, buf)) {
if (val > 7 && val < 11)
val = WD33C93_FS_8_10;
else if (val > 11 && val < 16)
val = WD33C93_FS_12_15;
else if (val > 15 && val < 21)
val = WD33C93_FS_16_20;
else
val = WD33C93_FS_8_10;
hostdata->clock_freq = val;
}
if (check_setup_args("burst", &flags, &val, buf))
hostdata->dma_mode = val ? CTRL_BURST:CTRL_DMA;
if (WD33C93_FS_16_20 == hostdata->clock_freq /* divisor 4 */
&& check_setup_args("fast", &flags, &val, buf))
hostdata->fast = !!val;
if ((i = check_setup_args("next", &flags, &val, buf))) {
while (i)
@ -1917,53 +2067,65 @@ wd33c93_proc_info(struct Scsi_Host *instance, char *buf, char **start, off_t off
char tbuf[128];
struct WD33C93_hostdata *hd;
struct scsi_cmnd *cmd;
int x, i;
int x;
static int stop = 0;
hd = (struct WD33C93_hostdata *) instance->hostdata;
/* If 'in' is TRUE we need to _read_ the proc file. We accept the following
* keywords (same format as command-line, but only ONE per read):
* keywords (same format as command-line, but arguments are not optional):
* debug
* disconnect
* period
* resync
* proc
* nodma
* level2
* burst
* fast
* nosync
*/
if (in) {
buf[len] = '\0';
bp = buf;
for (bp = buf; *bp; ) {
while (',' == *bp || ' ' == *bp)
++bp;
if (!strncmp(bp, "debug:", 6)) {
bp += 6;
hd->args = simple_strtoul(bp, NULL, 0) & DB_MASK;
hd->args = simple_strtoul(bp+6, &bp, 0) & DB_MASK;
} else if (!strncmp(bp, "disconnect:", 11)) {
bp += 11;
x = simple_strtoul(bp, NULL, 0);
x = simple_strtoul(bp+11, &bp, 0);
if (x < DIS_NEVER || x > DIS_ALWAYS)
x = DIS_ADAPTIVE;
hd->disconnect = x;
} else if (!strncmp(bp, "period:", 7)) {
bp += 7;
x = simple_strtoul(bp, NULL, 0);
x = simple_strtoul(bp+7, &bp, 0);
hd->default_sx_per =
sx_table[round_period((unsigned int) x)].period_ns;
hd->sx_table[round_period((unsigned int) x,
hd->sx_table)].period_ns;
} else if (!strncmp(bp, "resync:", 7)) {
bp += 7;
x = simple_strtoul(bp, NULL, 0);
for (i = 0; i < 7; i++)
if (x & (1 << i))
hd->sync_stat[i] = SS_UNSET;
set_resync(hd, (int)simple_strtoul(bp+7, &bp, 0));
} else if (!strncmp(bp, "proc:", 5)) {
bp += 5;
hd->proc = simple_strtoul(bp, NULL, 0);
hd->proc = simple_strtoul(bp+5, &bp, 0);
} else if (!strncmp(bp, "nodma:", 6)) {
bp += 6;
hd->no_dma = simple_strtoul(bp, NULL, 0);
hd->no_dma = simple_strtoul(bp+6, &bp, 0);
} else if (!strncmp(bp, "level2:", 7)) {
bp += 7;
hd->level2 = simple_strtoul(bp, NULL, 0);
hd->level2 = simple_strtoul(bp+7, &bp, 0);
} else if (!strncmp(bp, "burst:", 6)) {
hd->dma_mode =
simple_strtol(bp+6, &bp, 0) ? CTRL_BURST:CTRL_DMA;
} else if (!strncmp(bp, "fast:", 5)) {
x = !!simple_strtol(bp+5, &bp, 0);
if (x != hd->fast)
set_resync(hd, 0xff);
hd->fast = x;
} else if (!strncmp(bp, "nosync:", 7)) {
x = simple_strtoul(bp+7, &bp, 0);
set_resync(hd, x ^ hd->no_sync);
hd->no_sync = x;
} else {
break; /* unknown keyword,syntax-error,... */
}
}
return len;
}
@ -1977,8 +2139,9 @@ wd33c93_proc_info(struct Scsi_Host *instance, char *buf, char **start, off_t off
strcat(bp, tbuf);
}
if (hd->proc & PR_INFO) {
sprintf(tbuf, "\nclock_freq=%02x no_sync=%02x no_dma=%d",
hd->clock_freq, hd->no_sync, hd->no_dma);
sprintf(tbuf, "\nclock_freq=%02x no_sync=%02x no_dma=%d"
" dma_mode=%02x fast=%d",
hd->clock_freq, hd->no_sync, hd->no_dma, hd->dma_mode, hd->fast);
strcat(bp, tbuf);
strcat(bp, "\nsync_xfer[] = ");
for (x = 0; x < 7; x++) {

6
drivers/scsi/wd33c93.h
View File

@ -155,6 +155,9 @@
#define WD33C93_FS_12_15 OWNID_FS_12
#define WD33C93_FS_16_20 OWNID_FS_16
/* pass input-clock explicitely. accepted mhz values are 8-10,12-20 */
#define WD33C93_FS_MHZ(mhz) (mhz)
/* Control register */
#define CTRL_HSP 0x01
#define CTRL_HA 0x02
@ -253,6 +256,9 @@ struct WD33C93_hostdata {
uchar sync_stat[8]; /* status of sync negotiation per target */
uchar no_sync; /* bitmask: don't do sync on these targets */
uchar no_dma; /* set this flag to disable DMA */
uchar dma_mode; /* DMA Burst Mode or Single Byte DMA */
uchar fast; /* set this flag to enable Fast SCSI */
struct sx_period sx_table[9]; /* transfer periods for actual DTC-setting */
#ifdef PROC_INTERFACE
uchar proc; /* bitmask: what's in proc output */
#ifdef PROC_STATISTICS