linux/drivers/scsi/mac_scsi.c
Finn Thain 7c1f3e3447 scsi: mac_scsi: Treat Last Byte Sent time-out as failure
A system bus error during a PDMA send operation can result in bytes being
lost. Theoretically that could cause the target to remain in DATA OUT phase
and the initiator (expecting a phase change) would time-out waiting for the
Last Byte Sent flag. Should that happen, fail the transfer so the core
driver will stop using PDMA with this target.

Cc: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-06-20 15:37:03 -04:00

547 lines
16 KiB
C

/*
* Generic Macintosh NCR5380 driver
*
* Copyright 1998, Michael Schmitz <mschmitz@lbl.gov>
*
* Copyright 2019 Finn Thain
*
* derived in part from:
*/
/*
* Generic Generic NCR5380 driver
*
* Copyright 1995, Russell King
*/
#include <linux/delay.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <asm/hwtest.h>
#include <asm/io.h>
#include <asm/macintosh.h>
#include <asm/macints.h>
#include <asm/setup.h>
#include <scsi/scsi_host.h>
/* Definitions for the core NCR5380 driver. */
#define NCR5380_implementation_fields int pdma_residual
#define NCR5380_read(reg) in_8(hostdata->io + ((reg) << 4))
#define NCR5380_write(reg, value) out_8(hostdata->io + ((reg) << 4), value)
#define NCR5380_dma_xfer_len macscsi_dma_xfer_len
#define NCR5380_dma_recv_setup macscsi_pread
#define NCR5380_dma_send_setup macscsi_pwrite
#define NCR5380_dma_residual macscsi_dma_residual
#define NCR5380_intr macscsi_intr
#define NCR5380_queue_command macscsi_queue_command
#define NCR5380_abort macscsi_abort
#define NCR5380_host_reset macscsi_host_reset
#define NCR5380_info macscsi_info
#include "NCR5380.h"
static int setup_can_queue = -1;
module_param(setup_can_queue, int, 0);
static int setup_cmd_per_lun = -1;
module_param(setup_cmd_per_lun, int, 0);
static int setup_sg_tablesize = -1;
module_param(setup_sg_tablesize, int, 0);
static int setup_use_pdma = 512;
module_param(setup_use_pdma, int, 0);
static int setup_hostid = -1;
module_param(setup_hostid, int, 0);
static int setup_toshiba_delay = -1;
module_param(setup_toshiba_delay, int, 0);
#ifndef MODULE
static int __init mac_scsi_setup(char *str)
{
int ints[8];
(void)get_options(str, ARRAY_SIZE(ints), ints);
if (ints[0] < 1) {
pr_err("Usage: mac5380=<can_queue>[,<cmd_per_lun>[,<sg_tablesize>[,<hostid>[,<use_tags>[,<use_pdma>[,<toshiba_delay>]]]]]]\n");
return 0;
}
if (ints[0] >= 1)
setup_can_queue = ints[1];
if (ints[0] >= 2)
setup_cmd_per_lun = ints[2];
if (ints[0] >= 3)
setup_sg_tablesize = ints[3];
if (ints[0] >= 4)
setup_hostid = ints[4];
/* ints[5] (use_tagged_queuing) is ignored */
if (ints[0] >= 6)
setup_use_pdma = ints[6];
if (ints[0] >= 7)
setup_toshiba_delay = ints[7];
return 1;
}
__setup("mac5380=", mac_scsi_setup);
#endif /* !MODULE */
/*
* According to "Inside Macintosh: Devices", Mac OS requires disk drivers to
* specify the number of bytes between the delays expected from a SCSI target.
* This allows the operating system to "prevent bus errors when a target fails
* to deliver the next byte within the processor bus error timeout period."
* Linux SCSI drivers lack knowledge of the timing behaviour of SCSI targets
* so bus errors are unavoidable.
*
* If a MOVE.B instruction faults, we assume that zero bytes were transferred
* and simply retry. That assumption probably depends on target behaviour but
* seems to hold up okay. The NOP provides synchronization: without it the
* fault can sometimes occur after the program counter has moved past the
* offending instruction. Post-increment addressing can't be used.
*/
#define MOVE_BYTE(operands) \
asm volatile ( \
"1: moveb " operands " \n" \
"11: nop \n" \
" addq #1,%0 \n" \
" subq #1,%1 \n" \
"40: \n" \
" \n" \
".section .fixup,\"ax\" \n" \
".even \n" \
"90: movel #1, %2 \n" \
" jra 40b \n" \
".previous \n" \
" \n" \
".section __ex_table,\"a\" \n" \
".align 4 \n" \
".long 1b,90b \n" \
".long 11b,90b \n" \
".previous \n" \
: "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
/*
* If a MOVE.W (or MOVE.L) instruction faults, it cannot be retried because
* the residual byte count would be uncertain. In that situation the MOVE_WORD
* macro clears n in the fixup section to abort the transfer.
*/
#define MOVE_WORD(operands) \
asm volatile ( \
"1: movew " operands " \n" \
"11: nop \n" \
" subq #2,%1 \n" \
"40: \n" \
" \n" \
".section .fixup,\"ax\" \n" \
".even \n" \
"90: movel #0, %1 \n" \
" movel #2, %2 \n" \
" jra 40b \n" \
".previous \n" \
" \n" \
".section __ex_table,\"a\" \n" \
".align 4 \n" \
".long 1b,90b \n" \
".long 11b,90b \n" \
".previous \n" \
: "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
#define MOVE_16_WORDS(operands) \
asm volatile ( \
"1: movew " operands " \n" \
"2: movew " operands " \n" \
"3: movew " operands " \n" \
"4: movew " operands " \n" \
"5: movew " operands " \n" \
"6: movew " operands " \n" \
"7: movew " operands " \n" \
"8: movew " operands " \n" \
"9: movew " operands " \n" \
"10: movew " operands " \n" \
"11: movew " operands " \n" \
"12: movew " operands " \n" \
"13: movew " operands " \n" \
"14: movew " operands " \n" \
"15: movew " operands " \n" \
"16: movew " operands " \n" \
"17: nop \n" \
" subl #32,%1 \n" \
"40: \n" \
" \n" \
".section .fixup,\"ax\" \n" \
".even \n" \
"90: movel #0, %1 \n" \
" movel #2, %2 \n" \
" jra 40b \n" \
".previous \n" \
" \n" \
".section __ex_table,\"a\" \n" \
".align 4 \n" \
".long 1b,90b \n" \
".long 2b,90b \n" \
".long 3b,90b \n" \
".long 4b,90b \n" \
".long 5b,90b \n" \
".long 6b,90b \n" \
".long 7b,90b \n" \
".long 8b,90b \n" \
".long 9b,90b \n" \
".long 10b,90b \n" \
".long 11b,90b \n" \
".long 12b,90b \n" \
".long 13b,90b \n" \
".long 14b,90b \n" \
".long 15b,90b \n" \
".long 16b,90b \n" \
".long 17b,90b \n" \
".previous \n" \
: "+a" (addr), "+r" (n), "+r" (result) : "a" (io))
#define MAC_PDMA_DELAY 32
static inline int mac_pdma_recv(void __iomem *io, unsigned char *start, int n)
{
unsigned char *addr = start;
int result = 0;
if (n >= 1) {
MOVE_BYTE("%3@,%0@");
if (result)
goto out;
}
if (n >= 1 && ((unsigned long)addr & 1)) {
MOVE_BYTE("%3@,%0@");
if (result)
goto out;
}
while (n >= 32)
MOVE_16_WORDS("%3@,%0@+");
while (n >= 2)
MOVE_WORD("%3@,%0@+");
if (result)
return start - addr; /* Negated to indicate uncertain length */
if (n == 1)
MOVE_BYTE("%3@,%0@");
out:
return addr - start;
}
static inline int mac_pdma_send(unsigned char *start, void __iomem *io, int n)
{
unsigned char *addr = start;
int result = 0;
if (n >= 1) {
MOVE_BYTE("%0@,%3@");
if (result)
goto out;
}
if (n >= 1 && ((unsigned long)addr & 1)) {
MOVE_BYTE("%0@,%3@");
if (result)
goto out;
}
while (n >= 32)
MOVE_16_WORDS("%0@+,%3@");
while (n >= 2)
MOVE_WORD("%0@+,%3@");
if (result)
return start - addr; /* Negated to indicate uncertain length */
if (n == 1)
MOVE_BYTE("%0@,%3@");
out:
return addr - start;
}
/* The "SCSI DMA" chip on the IIfx implements this register. */
#define CTRL_REG 0x8
#define CTRL_INTERRUPTS_ENABLE BIT(1)
#define CTRL_HANDSHAKE_MODE BIT(3)
static inline void write_ctrl_reg(struct NCR5380_hostdata *hostdata, u32 value)
{
out_be32(hostdata->io + (CTRL_REG << 4), value);
}
static inline int macscsi_pread(struct NCR5380_hostdata *hostdata,
unsigned char *dst, int len)
{
u8 __iomem *s = hostdata->pdma_io + (INPUT_DATA_REG << 4);
unsigned char *d = dst;
int result = 0;
hostdata->pdma_residual = len;
while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
BASR_DRQ | BASR_PHASE_MATCH,
BASR_DRQ | BASR_PHASE_MATCH, HZ / 64)) {
int bytes;
if (macintosh_config->ident == MAC_MODEL_IIFX)
write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE |
CTRL_INTERRUPTS_ENABLE);
bytes = mac_pdma_recv(s, d, min(hostdata->pdma_residual, 512));
if (bytes > 0) {
d += bytes;
hostdata->pdma_residual -= bytes;
}
if (hostdata->pdma_residual == 0)
goto out;
if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ,
BUS_AND_STATUS_REG, BASR_ACK,
BASR_ACK, HZ / 64) < 0)
scmd_printk(KERN_DEBUG, hostdata->connected,
"%s: !REQ and !ACK\n", __func__);
if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH))
goto out;
if (bytes == 0)
udelay(MAC_PDMA_DELAY);
if (bytes >= 0)
continue;
dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
"%s: bus error (%d/%d)\n", __func__, d - dst, len);
NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
result = -1;
goto out;
}
scmd_printk(KERN_ERR, hostdata->connected,
"%s: phase mismatch or !DRQ\n", __func__);
NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
result = -1;
out:
if (macintosh_config->ident == MAC_MODEL_IIFX)
write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
return result;
}
static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata,
unsigned char *src, int len)
{
unsigned char *s = src;
u8 __iomem *d = hostdata->pdma_io + (OUTPUT_DATA_REG << 4);
int result = 0;
hostdata->pdma_residual = len;
while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG,
BASR_DRQ | BASR_PHASE_MATCH,
BASR_DRQ | BASR_PHASE_MATCH, HZ / 64)) {
int bytes;
if (macintosh_config->ident == MAC_MODEL_IIFX)
write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE |
CTRL_INTERRUPTS_ENABLE);
bytes = mac_pdma_send(s, d, min(hostdata->pdma_residual, 512));
if (bytes > 0) {
s += bytes;
hostdata->pdma_residual -= bytes;
}
if (hostdata->pdma_residual == 0) {
if (NCR5380_poll_politely(hostdata, TARGET_COMMAND_REG,
TCR_LAST_BYTE_SENT,
TCR_LAST_BYTE_SENT,
HZ / 64) < 0) {
scmd_printk(KERN_ERR, hostdata->connected,
"%s: Last Byte Sent timeout\n", __func__);
result = -1;
}
goto out;
}
if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ,
BUS_AND_STATUS_REG, BASR_ACK,
BASR_ACK, HZ / 64) < 0)
scmd_printk(KERN_DEBUG, hostdata->connected,
"%s: !REQ and !ACK\n", __func__);
if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH))
goto out;
if (bytes == 0)
udelay(MAC_PDMA_DELAY);
if (bytes >= 0)
continue;
dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host,
"%s: bus error (%d/%d)\n", __func__, s - src, len);
NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
result = -1;
goto out;
}
scmd_printk(KERN_ERR, hostdata->connected,
"%s: phase mismatch or !DRQ\n", __func__);
NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host);
result = -1;
out:
if (macintosh_config->ident == MAC_MODEL_IIFX)
write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE);
return result;
}
static int macscsi_dma_xfer_len(struct NCR5380_hostdata *hostdata,
struct scsi_cmnd *cmd)
{
if (hostdata->flags & FLAG_NO_PSEUDO_DMA ||
cmd->SCp.this_residual < setup_use_pdma)
return 0;
return cmd->SCp.this_residual;
}
static int macscsi_dma_residual(struct NCR5380_hostdata *hostdata)
{
return hostdata->pdma_residual;
}
#include "NCR5380.c"
#define DRV_MODULE_NAME "mac_scsi"
#define PFX DRV_MODULE_NAME ": "
static struct scsi_host_template mac_scsi_template = {
.module = THIS_MODULE,
.proc_name = DRV_MODULE_NAME,
.name = "Macintosh NCR5380 SCSI",
.info = macscsi_info,
.queuecommand = macscsi_queue_command,
.eh_abort_handler = macscsi_abort,
.eh_host_reset_handler = macscsi_host_reset,
.can_queue = 16,
.this_id = 7,
.sg_tablesize = 1,
.cmd_per_lun = 2,
.dma_boundary = PAGE_SIZE - 1,
.cmd_size = NCR5380_CMD_SIZE,
.max_sectors = 128,
};
static int __init mac_scsi_probe(struct platform_device *pdev)
{
struct Scsi_Host *instance;
struct NCR5380_hostdata *hostdata;
int error;
int host_flags = 0;
struct resource *irq, *pio_mem, *pdma_mem = NULL;
pio_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!pio_mem)
return -ENODEV;
pdma_mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!hwreg_present((unsigned char *)pio_mem->start +
(STATUS_REG << 4))) {
pr_info(PFX "no device detected at %pap\n", &pio_mem->start);
return -ENODEV;
}
if (setup_can_queue > 0)
mac_scsi_template.can_queue = setup_can_queue;
if (setup_cmd_per_lun > 0)
mac_scsi_template.cmd_per_lun = setup_cmd_per_lun;
if (setup_sg_tablesize >= 0)
mac_scsi_template.sg_tablesize = setup_sg_tablesize;
if (setup_hostid >= 0)
mac_scsi_template.this_id = setup_hostid & 7;
instance = scsi_host_alloc(&mac_scsi_template,
sizeof(struct NCR5380_hostdata));
if (!instance)
return -ENOMEM;
if (irq)
instance->irq = irq->start;
else
instance->irq = NO_IRQ;
hostdata = shost_priv(instance);
hostdata->base = pio_mem->start;
hostdata->io = (u8 __iomem *)pio_mem->start;
if (pdma_mem && setup_use_pdma)
hostdata->pdma_io = (u8 __iomem *)pdma_mem->start;
else
host_flags |= FLAG_NO_PSEUDO_DMA;
host_flags |= setup_toshiba_delay > 0 ? FLAG_TOSHIBA_DELAY : 0;
error = NCR5380_init(instance, host_flags | FLAG_LATE_DMA_SETUP);
if (error)
goto fail_init;
if (instance->irq != NO_IRQ) {
error = request_irq(instance->irq, macscsi_intr, IRQF_SHARED,
"NCR5380", instance);
if (error)
goto fail_irq;
}
NCR5380_maybe_reset_bus(instance);
error = scsi_add_host(instance, NULL);
if (error)
goto fail_host;
platform_set_drvdata(pdev, instance);
scsi_scan_host(instance);
return 0;
fail_host:
if (instance->irq != NO_IRQ)
free_irq(instance->irq, instance);
fail_irq:
NCR5380_exit(instance);
fail_init:
scsi_host_put(instance);
return error;
}
static int __exit mac_scsi_remove(struct platform_device *pdev)
{
struct Scsi_Host *instance = platform_get_drvdata(pdev);
scsi_remove_host(instance);
if (instance->irq != NO_IRQ)
free_irq(instance->irq, instance);
NCR5380_exit(instance);
scsi_host_put(instance);
return 0;
}
static struct platform_driver mac_scsi_driver = {
.remove = __exit_p(mac_scsi_remove),
.driver = {
.name = DRV_MODULE_NAME,
},
};
module_platform_driver_probe(mac_scsi_driver, mac_scsi_probe);
MODULE_ALIAS("platform:" DRV_MODULE_NAME);
MODULE_LICENSE("GPL");