linux_dsm_epyc7002/drivers/scsi/dtc.c
Finn Thain 0a4e361254 ncr5380: Fix soft lockups
Because of the rudimentary design of the chip, it is necessary to poll the
SCSI bus signals during PIO and this tends to hog the CPU. The driver will
accept new commands while others execute, and this causes a soft lockup
because the workqueue item will not terminate until the issue queue is
emptied.

When exercising dmx3191d using sequential IO from dd, the driver is sent
512 KiB WRITE commands and 128 KiB READs. For a PIO transfer, the rate is
is only about 300 KiB/s, so these are long-running commands. And although
PDMA may run at several MiB/s, interrupts are disabled for the duration
of the transfer.

Fix the unresponsiveness and soft lockup issues by calling cond_resched()
after each command is completed and by limiting max_sectors for drivers
that don't implement real DMA.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-01-06 21:43:09 -05:00

459 lines
12 KiB
C

#define PSEUDO_DMA
#define DONT_USE_INTR
/*
* DTC 3180/3280 driver, by
* Ray Van Tassle rayvt@comm.mot.com
*
* taken from ...
* Trantor T128/T128F/T228 driver by...
*
* Drew Eckhardt
* Visionary Computing
* (Unix and Linux consulting and custom programming)
* drew@colorado.edu
* +1 (303) 440-4894
*/
/*
* The card is detected and initialized in one of several ways :
* 1. Autoprobe (default) - since the board is memory mapped,
* a BIOS signature is scanned for to locate the registers.
* An interrupt is triggered to autoprobe for the interrupt
* line.
*
* 2. With command line overrides - dtc=address,irq may be
* used on the LILO command line to override the defaults.
*
*/
/*----------------------------------------------------------------*/
/* the following will set the monitor border color (useful to find
where something crashed or gets stuck at */
/* 1 = blue
2 = green
3 = cyan
4 = red
5 = magenta
6 = yellow
7 = white
*/
#if 0
#define rtrc(i) {inb(0x3da); outb(0x31, 0x3c0); outb((i), 0x3c0);}
#else
#define rtrc(i) {}
#endif
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <scsi/scsi_host.h>
#include "dtc.h"
#define AUTOPROBE_IRQ
#include "NCR5380.h"
/*
* The DTC3180 & 3280 boards are memory mapped.
*
*/
/*
*/
/* Offset from DTC_5380_OFFSET */
#define DTC_CONTROL_REG 0x100 /* rw */
#define D_CR_ACCESS 0x80 /* ro set=can access 3280 registers */
#define CSR_DIR_READ 0x40 /* rw direction, 1 = read 0 = write */
#define CSR_RESET 0x80 /* wo Resets 53c400 */
#define CSR_5380_REG 0x80 /* ro 5380 registers can be accessed */
#define CSR_TRANS_DIR 0x40 /* rw Data transfer direction */
#define CSR_SCSI_BUFF_INTR 0x20 /* rw Enable int on transfer ready */
#define CSR_5380_INTR 0x10 /* rw Enable 5380 interrupts */
#define CSR_SHARED_INTR 0x08 /* rw Interrupt sharing */
#define CSR_HOST_BUF_NOT_RDY 0x04 /* ro Host buffer not ready */
#define CSR_SCSI_BUF_RDY 0x02 /* ro SCSI buffer ready */
#define CSR_GATED_5380_IRQ 0x01 /* ro Last block xferred */
#define CSR_INT_BASE (CSR_SCSI_BUFF_INTR | CSR_5380_INTR)
#define DTC_BLK_CNT 0x101 /* rw
* # of 128-byte blocks to transfer */
#define D_CR_ACCESS 0x80 /* ro set=can access 3280 registers */
#define DTC_SWITCH_REG 0x3982 /* ro - DIP switches */
#define DTC_RESUME_XFER 0x3982 /* wo - resume data xfer
* after disconnect/reconnect*/
#define DTC_5380_OFFSET 0x3880 /* 8 registers here, see NCR5380.h */
/*!!!! for dtc, it's a 128 byte buffer at 3900 !!! */
#define DTC_DATA_BUF 0x3900 /* rw 128 bytes long */
static struct override {
unsigned int address;
int irq;
} overrides
#ifdef OVERRIDE
[] __initdata = OVERRIDE;
#else
[4] __initdata = {
{ 0, IRQ_AUTO }, { 0, IRQ_AUTO }, { 0, IRQ_AUTO }, { 0, IRQ_AUTO }
};
#endif
#define NO_OVERRIDES ARRAY_SIZE(overrides)
static struct base {
unsigned long address;
int noauto;
} bases[] __initdata = {
{ 0xcc000, 0 },
{ 0xc8000, 0 },
{ 0xdc000, 0 },
{ 0xd8000, 0 }
};
#define NO_BASES ARRAY_SIZE(bases)
static const struct signature {
const char *string;
int offset;
} signatures[] = {
{"DATA TECHNOLOGY CORPORATION BIOS", 0x25},
};
#define NO_SIGNATURES ARRAY_SIZE(signatures)
#ifndef MODULE
/*
* Function : dtc_setup(char *str, int *ints)
*
* Purpose : LILO command line initialization of the overrides array,
*
* Inputs : str - unused, ints - array of integer parameters with ints[0]
* equal to the number of ints.
*
*/
static int __init dtc_setup(char *str)
{
static int commandline_current;
int i;
int ints[10];
get_options(str, ARRAY_SIZE(ints), ints);
if (ints[0] != 2)
printk("dtc_setup: usage dtc=address,irq\n");
else if (commandline_current < NO_OVERRIDES) {
overrides[commandline_current].address = ints[1];
overrides[commandline_current].irq = ints[2];
for (i = 0; i < NO_BASES; ++i)
if (bases[i].address == ints[1]) {
bases[i].noauto = 1;
break;
}
++commandline_current;
}
return 1;
}
__setup("dtc=", dtc_setup);
#endif
/*
* Function : int dtc_detect(struct scsi_host_template * tpnt)
*
* Purpose : detects and initializes DTC 3180/3280 controllers
* that were autoprobed, overridden on the LILO command line,
* or specified at compile time.
*
* Inputs : tpnt - template for this SCSI adapter.
*
* Returns : 1 if a host adapter was found, 0 if not.
*
*/
static int __init dtc_detect(struct scsi_host_template * tpnt)
{
static int current_override, current_base;
struct Scsi_Host *instance;
unsigned int addr;
void __iomem *base;
int sig, count;
for (count = 0; current_override < NO_OVERRIDES; ++current_override) {
addr = 0;
base = NULL;
if (overrides[current_override].address) {
addr = overrides[current_override].address;
base = ioremap(addr, 0x2000);
if (!base)
addr = 0;
} else
for (; !addr && (current_base < NO_BASES); ++current_base) {
dprintk(NDEBUG_INIT, "dtc: probing address 0x%08x\n",
(unsigned int)bases[current_base].address);
if (bases[current_base].noauto)
continue;
base = ioremap(bases[current_base].address, 0x2000);
if (!base)
continue;
for (sig = 0; sig < NO_SIGNATURES; ++sig) {
if (check_signature(base + signatures[sig].offset, signatures[sig].string, strlen(signatures[sig].string))) {
addr = bases[current_base].address;
dprintk(NDEBUG_INIT, "dtc: detected board\n");
goto found;
}
}
iounmap(base);
}
dprintk(NDEBUG_INIT, "dtc: addr = 0x%08x\n", addr);
if (!addr)
break;
found:
instance = scsi_register(tpnt, sizeof(struct NCR5380_hostdata));
if (instance == NULL)
goto out_unmap;
instance->base = addr;
((struct NCR5380_hostdata *)(instance)->hostdata)->base = base;
if (NCR5380_init(instance, FLAG_NO_DMA_FIXUP))
goto out_unregister;
NCR5380_maybe_reset_bus(instance);
NCR5380_write(DTC_CONTROL_REG, CSR_5380_INTR); /* Enable int's */
if (overrides[current_override].irq != IRQ_AUTO)
instance->irq = overrides[current_override].irq;
else
instance->irq = NCR5380_probe_irq(instance, DTC_IRQS);
/* Compatibility with documented NCR5380 kernel parameters */
if (instance->irq == 255)
instance->irq = NO_IRQ;
#ifndef DONT_USE_INTR
/* With interrupts enabled, it will sometimes hang when doing heavy
* reads. So better not enable them until I finger it out. */
if (instance->irq != NO_IRQ)
if (request_irq(instance->irq, dtc_intr, 0,
"dtc", instance)) {
printk(KERN_ERR "scsi%d : IRQ%d not free, interrupts disabled\n", instance->host_no, instance->irq);
instance->irq = NO_IRQ;
}
if (instance->irq == NO_IRQ) {
printk(KERN_WARNING "scsi%d : interrupts not enabled. for better interactive performance,\n", instance->host_no);
printk(KERN_WARNING "scsi%d : please jumper the board for a free IRQ.\n", instance->host_no);
}
#else
if (instance->irq != NO_IRQ)
printk(KERN_WARNING "scsi%d : interrupts not used. Might as well not jumper it.\n", instance->host_no);
instance->irq = NO_IRQ;
#endif
dprintk(NDEBUG_INIT, "scsi%d : irq = %d\n",
instance->host_no, instance->irq);
++current_override;
++count;
}
return count;
out_unregister:
scsi_unregister(instance);
out_unmap:
iounmap(base);
return count;
}
/*
* Function : int dtc_biosparam(Disk * disk, struct block_device *dev, int *ip)
*
* Purpose : Generates a BIOS / DOS compatible H-C-S mapping for
* the specified device / size.
*
* Inputs : size = size of device in sectors (512 bytes), dev = block device
* major / minor, ip[] = {heads, sectors, cylinders}
*
* Returns : always 0 (success), initializes ip
*
*/
/*
* XXX Most SCSI boards use this mapping, I could be incorrect. Some one
* using hard disks on a trantor should verify that this mapping corresponds
* to that used by the BIOS / ASPI driver by running the linux fdisk program
* and matching the H_C_S coordinates to what DOS uses.
*/
static int dtc_biosparam(struct scsi_device *sdev, struct block_device *dev,
sector_t capacity, int *ip)
{
int size = capacity;
ip[0] = 64;
ip[1] = 32;
ip[2] = size >> 11;
return 0;
}
/****************************************************************
* Function : int NCR5380_pread (struct Scsi_Host *instance,
* unsigned char *dst, int len)
*
* Purpose : Fast 5380 pseudo-dma read function, reads len bytes to
* dst
*
* Inputs : dst = destination, len = length in bytes
*
* Returns : 0 on success, non zero on a failure such as a watchdog
* timeout.
*/
static inline int NCR5380_pread(struct Scsi_Host *instance, unsigned char *dst, int len)
{
unsigned char *d = dst;
int i; /* For counting time spent in the poll-loop */
struct NCR5380_hostdata *hostdata = shost_priv(instance);
i = 0;
if (instance->irq == NO_IRQ)
NCR5380_write(DTC_CONTROL_REG, CSR_DIR_READ);
else
NCR5380_write(DTC_CONTROL_REG, CSR_DIR_READ | CSR_INT_BASE);
NCR5380_write(DTC_BLK_CNT, len >> 7); /* Block count */
rtrc(1);
while (len > 0) {
rtrc(2);
while (NCR5380_read(DTC_CONTROL_REG) & CSR_HOST_BUF_NOT_RDY)
++i;
rtrc(3);
memcpy_fromio(d, hostdata->base + DTC_DATA_BUF, 128);
d += 128;
len -= 128;
rtrc(7);
/*** with int's on, it sometimes hangs after here.
* Looks like something makes HBNR go away. */
}
rtrc(4);
while (!(NCR5380_read(DTC_CONTROL_REG) & D_CR_ACCESS))
++i;
rtrc(0);
if (i > hostdata->spin_max_r)
hostdata->spin_max_r = i;
return (0);
}
/****************************************************************
* Function : int NCR5380_pwrite (struct Scsi_Host *instance,
* unsigned char *src, int len)
*
* Purpose : Fast 5380 pseudo-dma write function, transfers len bytes from
* src
*
* Inputs : src = source, len = length in bytes
*
* Returns : 0 on success, non zero on a failure such as a watchdog
* timeout.
*/
static inline int NCR5380_pwrite(struct Scsi_Host *instance, unsigned char *src, int len)
{
int i;
struct NCR5380_hostdata *hostdata = shost_priv(instance);
if (instance->irq == NO_IRQ)
NCR5380_write(DTC_CONTROL_REG, 0);
else
NCR5380_write(DTC_CONTROL_REG, CSR_5380_INTR);
NCR5380_write(DTC_BLK_CNT, len >> 7); /* Block count */
for (i = 0; len > 0; ++i) {
rtrc(5);
/* Poll until the host buffer can accept data. */
while (NCR5380_read(DTC_CONTROL_REG) & CSR_HOST_BUF_NOT_RDY)
++i;
rtrc(3);
memcpy_toio(hostdata->base + DTC_DATA_BUF, src, 128);
src += 128;
len -= 128;
}
rtrc(4);
while (!(NCR5380_read(DTC_CONTROL_REG) & D_CR_ACCESS))
++i;
rtrc(6);
/* Wait until the last byte has been sent to the disk */
while (!(NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT))
++i;
rtrc(7);
/* Check for parity error here. fixme. */
rtrc(0);
if (i > hostdata->spin_max_w)
hostdata->spin_max_w = i;
return (0);
}
static int dtc_dma_xfer_len(struct scsi_cmnd *cmd)
{
int transfersize = cmd->transfersize;
/* Limit transfers to 32K, for xx400 & xx406
* pseudoDMA that transfers in 128 bytes blocks.
*/
if (transfersize > 32 * 1024 && cmd->SCp.this_residual &&
!(cmd->SCp.this_residual % transfersize))
transfersize = 32 * 1024;
return transfersize;
}
MODULE_LICENSE("GPL");
#include "NCR5380.c"
static int dtc_release(struct Scsi_Host *shost)
{
struct NCR5380_hostdata *hostdata = shost_priv(shost);
if (shost->irq != NO_IRQ)
free_irq(shost->irq, shost);
NCR5380_exit(shost);
scsi_unregister(shost);
iounmap(hostdata->base);
return 0;
}
static struct scsi_host_template driver_template = {
.name = "DTC 3180/3280",
.detect = dtc_detect,
.release = dtc_release,
.proc_name = "dtc3x80",
.show_info = dtc_show_info,
.write_info = dtc_write_info,
.info = dtc_info,
.queuecommand = dtc_queue_command,
.eh_abort_handler = dtc_abort,
.eh_bus_reset_handler = dtc_bus_reset,
.bios_param = dtc_biosparam,
.can_queue = 32,
.this_id = 7,
.sg_tablesize = SG_ALL,
.cmd_per_lun = 2,
.use_clustering = DISABLE_CLUSTERING,
.cmd_size = NCR5380_CMD_SIZE,
.max_sectors = 128,
};
#include "scsi_module.c"