linux/drivers/scsi/atari_scsi.c

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/*
* atari_scsi.c -- Device dependent functions for the Atari generic SCSI port
*
* Copyright 1994 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
*
* Loosely based on the work of Robert De Vries' team and added:
* - working real DMA
* - Falcon support (untested yet!) ++bjoern fixed and now it works
* - lots of extensions and bug fixes.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive
* for more details.
*
*/
/*
* Notes for Falcon SCSI DMA
*
* The 5380 device is one of several that all share the DMA chip. Hence
* "locking" and "unlocking" access to this chip is required.
*
* Two possible schemes for ST DMA acquisition by atari_scsi are:
* 1) The lock is taken for each command separately (i.e. can_queue == 1).
* 2) The lock is taken when the first command arrives and released
* when the last command is finished (i.e. can_queue > 1).
*
* The first alternative limits SCSI bus utilization, since interleaving
* commands is not possible. The second gives better performance but is
* unfair to other drivers needing to use the ST DMA chip. In order to
* allow the IDE and floppy drivers equal access to the ST DMA chip
* the default is can_queue == 1.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/blkdev.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/nvram.h>
#include <linux/bitops.h>
#include <linux/wait.h>
#include <linux/platform_device.h>
#include <asm/setup.h>
#include <asm/atarihw.h>
#include <asm/atariints.h>
#include <asm/atari_stdma.h>
#include <asm/atari_stram.h>
#include <asm/io.h>
#include <scsi/scsi_host.h>
#define DMA_MIN_SIZE 32
/* Definitions for the core NCR5380 driver. */
#define NCR5380_implementation_fields /* none */
static u8 (*atari_scsi_reg_read)(unsigned int);
static void (*atari_scsi_reg_write)(unsigned int, u8);
#define NCR5380_read(reg) atari_scsi_reg_read(reg)
#define NCR5380_write(reg, value) atari_scsi_reg_write(reg, value)
#define NCR5380_queue_command atari_scsi_queue_command
#define NCR5380_abort atari_scsi_abort
#define NCR5380_info atari_scsi_info
#define NCR5380_dma_xfer_len atari_scsi_dma_xfer_len
#define NCR5380_dma_recv_setup atari_scsi_dma_recv_setup
#define NCR5380_dma_send_setup atari_scsi_dma_send_setup
#define NCR5380_dma_residual atari_scsi_dma_residual
#define NCR5380_acquire_dma_irq(instance) falcon_get_lock(instance)
#define NCR5380_release_dma_irq(instance) falcon_release_lock()
#include "NCR5380.h"
#define IS_A_TT() ATARIHW_PRESENT(TT_SCSI)
#define SCSI_DMA_WRITE_P(elt,val) \
do { \
unsigned long v = val; \
tt_scsi_dma.elt##_lo = v & 0xff; \
v >>= 8; \
tt_scsi_dma.elt##_lmd = v & 0xff; \
v >>= 8; \
tt_scsi_dma.elt##_hmd = v & 0xff; \
v >>= 8; \
tt_scsi_dma.elt##_hi = v & 0xff; \
} while(0)
#define SCSI_DMA_READ_P(elt) \
(((((((unsigned long)tt_scsi_dma.elt##_hi << 8) | \
(unsigned long)tt_scsi_dma.elt##_hmd) << 8) | \
(unsigned long)tt_scsi_dma.elt##_lmd) << 8) | \
(unsigned long)tt_scsi_dma.elt##_lo)
static inline void SCSI_DMA_SETADR(unsigned long adr)
{
st_dma.dma_lo = (unsigned char)adr;
MFPDELAY();
adr >>= 8;
st_dma.dma_md = (unsigned char)adr;
MFPDELAY();
adr >>= 8;
st_dma.dma_hi = (unsigned char)adr;
MFPDELAY();
}
static inline unsigned long SCSI_DMA_GETADR(void)
{
unsigned long adr;
adr = st_dma.dma_lo;
MFPDELAY();
adr |= (st_dma.dma_md & 0xff) << 8;
MFPDELAY();
adr |= (st_dma.dma_hi & 0xff) << 16;
MFPDELAY();
return adr;
}
static void atari_scsi_fetch_restbytes(void);
static unsigned long atari_dma_residual, atari_dma_startaddr;
static short atari_dma_active;
/* pointer to the dribble buffer */
static char *atari_dma_buffer;
/* precalculated physical address of the dribble buffer */
static unsigned long atari_dma_phys_buffer;
/* != 0 tells the Falcon int handler to copy data from the dribble buffer */
static char *atari_dma_orig_addr;
/* size of the dribble buffer; 4k seems enough, since the Falcon cannot use
* scatter-gather anyway, so most transfers are 1024 byte only. In the rare
* cases where requests to physical contiguous buffers have been merged, this
* request is <= 4k (one page). So I don't think we have to split transfers
* just due to this buffer size...
*/
#define STRAM_BUFFER_SIZE (4096)
/* mask for address bits that can't be used with the ST-DMA */
static unsigned long atari_dma_stram_mask;
#define STRAM_ADDR(a) (((a) & atari_dma_stram_mask) == 0)
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_hostid = -1;
module_param(setup_hostid, int, 0);
static int setup_toshiba_delay = -1;
module_param(setup_toshiba_delay, int, 0);
static int scsi_dma_is_ignored_buserr(unsigned char dma_stat)
{
int i;
unsigned long addr = SCSI_DMA_READ_P(dma_addr), end_addr;
if (dma_stat & 0x01) {
/* A bus error happens when DMA-ing from the last page of a
* physical memory chunk (DMA prefetch!), but that doesn't hurt.
* Check for this case:
*/
for (i = 0; i < m68k_num_memory; ++i) {
end_addr = m68k_memory[i].addr + m68k_memory[i].size;
if (end_addr <= addr && addr <= end_addr + 4)
return 1;
}
}
return 0;
}
static irqreturn_t scsi_tt_intr(int irq, void *dev)
{
struct Scsi_Host *instance = dev;
struct NCR5380_hostdata *hostdata = shost_priv(instance);
int dma_stat;
dma_stat = tt_scsi_dma.dma_ctrl;
dsprintk(NDEBUG_INTR, instance, "NCR5380 interrupt, DMA status = %02x\n",
dma_stat & 0xff);
/* Look if it was the DMA that has interrupted: First possibility
* is that a bus error occurred...
*/
if (dma_stat & 0x80) {
if (!scsi_dma_is_ignored_buserr(dma_stat)) {
printk(KERN_ERR "SCSI DMA caused bus error near 0x%08lx\n",
SCSI_DMA_READ_P(dma_addr));
printk(KERN_CRIT "SCSI DMA bus error -- bad DMA programming!");
}
}
/* If the DMA is active but not finished, we have the case
* that some other 5380 interrupt occurred within the DMA transfer.
* This means we have residual bytes, if the desired end address
* is not yet reached. Maybe we have to fetch some bytes from the
* rest data register, too. The residual must be calculated from
* the address pointer, not the counter register, because only the
* addr reg counts bytes not yet written and pending in the rest
* data reg!
*/
if ((dma_stat & 0x02) && !(dma_stat & 0x40)) {
atari_dma_residual = hostdata->dma_len -
(SCSI_DMA_READ_P(dma_addr) - atari_dma_startaddr);
dprintk(NDEBUG_DMA, "SCSI DMA: There are %ld residual bytes.\n",
atari_dma_residual);
if ((signed int)atari_dma_residual < 0)
atari_dma_residual = 0;
if ((dma_stat & 1) == 0) {
/*
* After read operations, we maybe have to
* transport some rest bytes
*/
atari_scsi_fetch_restbytes();
} else {
/*
* There seems to be a nasty bug in some SCSI-DMA/NCR
* combinations: If a target disconnects while a write
* operation is going on, the address register of the
* DMA may be a few bytes farer than it actually read.
* This is probably due to DMA prefetching and a delay
* between DMA and NCR. Experiments showed that the
* dma_addr is 9 bytes to high, but this could vary.
* The problem is, that the residual is thus calculated
* wrong and the next transfer will start behind where
* it should. So we round up the residual to the next
* multiple of a sector size, if it isn't already a
* multiple and the originally expected transfer size
* was. The latter condition is there to ensure that
* the correction is taken only for "real" data
* transfers and not for, e.g., the parameters of some
* other command. These shouldn't disconnect anyway.
*/
if (atari_dma_residual & 0x1ff) {
dprintk(NDEBUG_DMA, "SCSI DMA: DMA bug corrected, "
"difference %ld bytes\n",
512 - (atari_dma_residual & 0x1ff));
atari_dma_residual = (atari_dma_residual + 511) & ~0x1ff;
}
}
tt_scsi_dma.dma_ctrl = 0;
}
/* If the DMA is finished, fetch the rest bytes and turn it off */
if (dma_stat & 0x40) {
atari_dma_residual = 0;
if ((dma_stat & 1) == 0)
atari_scsi_fetch_restbytes();
tt_scsi_dma.dma_ctrl = 0;
}
NCR5380_intr(irq, dev);
return IRQ_HANDLED;
}
static irqreturn_t scsi_falcon_intr(int irq, void *dev)
{
struct Scsi_Host *instance = dev;
struct NCR5380_hostdata *hostdata = shost_priv(instance);
int dma_stat;
/* Turn off DMA and select sector counter register before
* accessing the status register (Atari recommendation!)
*/
st_dma.dma_mode_status = 0x90;
dma_stat = st_dma.dma_mode_status;
/* Bit 0 indicates some error in the DMA process... don't know
* what happened exactly (no further docu).
*/
if (!(dma_stat & 0x01)) {
/* DMA error */
printk(KERN_CRIT "SCSI DMA error near 0x%08lx!\n", SCSI_DMA_GETADR());
}
/* If the DMA was active, but now bit 1 is not clear, it is some
* other 5380 interrupt that finishes the DMA transfer. We have to
* calculate the number of residual bytes and give a warning if
* bytes are stuck in the ST-DMA fifo (there's no way to reach them!)
*/
if (atari_dma_active && (dma_stat & 0x02)) {
unsigned long transferred;
transferred = SCSI_DMA_GETADR() - atari_dma_startaddr;
/* The ST-DMA address is incremented in 2-byte steps, but the
* data are written only in 16-byte chunks. If the number of
* transferred bytes is not divisible by 16, the remainder is
* lost somewhere in outer space.
*/
if (transferred & 15)
printk(KERN_ERR "SCSI DMA error: %ld bytes lost in "
"ST-DMA fifo\n", transferred & 15);
atari_dma_residual = hostdata->dma_len - transferred;
dprintk(NDEBUG_DMA, "SCSI DMA: There are %ld residual bytes.\n",
atari_dma_residual);
} else
atari_dma_residual = 0;
atari_dma_active = 0;
if (atari_dma_orig_addr) {
/* If the dribble buffer was used on a read operation, copy the DMA-ed
* data to the original destination address.
*/
memcpy(atari_dma_orig_addr, phys_to_virt(atari_dma_startaddr),
hostdata->dma_len - atari_dma_residual);
atari_dma_orig_addr = NULL;
}
NCR5380_intr(irq, dev);
return IRQ_HANDLED;
}
static void atari_scsi_fetch_restbytes(void)
{
int nr;
char *src, *dst;
unsigned long phys_dst;
/* fetch rest bytes in the DMA register */
phys_dst = SCSI_DMA_READ_P(dma_addr);
nr = phys_dst & 3;
if (nr) {
/* there are 'nr' bytes left for the last long address
before the DMA pointer */
phys_dst ^= nr;
dprintk(NDEBUG_DMA, "SCSI DMA: there are %d rest bytes for phys addr 0x%08lx",
nr, phys_dst);
/* The content of the DMA pointer is a physical address! */
dst = phys_to_virt(phys_dst);
dprintk(NDEBUG_DMA, " = virt addr %p\n", dst);
for (src = (char *)&tt_scsi_dma.dma_restdata; nr != 0; --nr)
*dst++ = *src++;
}
}
/* This function releases the lock on the DMA chip if there is no
* connected command and the disconnected queue is empty.
*/
static void falcon_release_lock(void)
{
if (IS_A_TT())
return;
if (stdma_is_locked_by(scsi_falcon_intr))
stdma_release();
}
/* This function manages the locking of the ST-DMA.
* If the DMA isn't locked already for SCSI, it tries to lock it by
* calling stdma_lock(). But if the DMA is locked by the SCSI code and
* there are other drivers waiting for the chip, we do not issue the
* command immediately but tell the SCSI mid-layer to defer.
*/
static int falcon_get_lock(struct Scsi_Host *instance)
{
if (IS_A_TT())
return 1;
if (stdma_is_locked_by(scsi_falcon_intr) &&
instance->hostt->can_queue > 1)
return 1;
if (in_interrupt())
return stdma_try_lock(scsi_falcon_intr, instance);
stdma_lock(scsi_falcon_intr, instance);
return 1;
}
#ifndef MODULE
static int __init atari_scsi_setup(char *str)
{
/* Format of atascsi parameter is:
* atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
* Defaults depend on TT or Falcon, determined at run time.
* Negative values mean don't change.
*/
int ints[8];
get_options(str, ARRAY_SIZE(ints), ints);
if (ints[0] < 1) {
printk("atari_scsi_setup: no arguments!\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];
ncr5380: Remove disused atari_NCR5380.c core driver Now that atari_scsi and sun3_scsi have been converted to use the NCR5380.c core driver, remove atari_NCR5380.c. Also remove the last vestiges of its Tagged Command Queueing implementation from the wrapper drivers. The TCQ support in atari_NCR5380.c is abandoned by this patch. It is not merged into the remaining core driver because, 1) atari_scsi defines SUPPORT_TAGS but leaves FLAG_TAGGED_QUEUING disabled by default, which indicates that it is mostly undesirable. 2) I'm told that it doesn't work correctly when enabled. 3) The algorithm does not make use of block layer tags which it will have to do because scmd->tag is deprecated. 4) sun3_scsi doesn't define SUPPORT_TAGS at all, yet the the SUPPORT_TAGS macro interacts with the CONFIG_SUN3 macro in 'interesting' ways. 5) Compile-time configuration with macros like SUPPORT_TAGS caused the configuration space to explode, leading to untestable and unmaintainable code that is too hard to reason about. The merge_contiguous_buffers() code is also abandoned. This was unused by sun3_scsi. Only atari_scsi used it and then only on TT, because only TT supports scatter/gather. I suspect that the TT would work fine with ENABLE_CLUSTERING instead. If someone can benchmark the difference then perhaps the merge_contiguous_buffers() code can be be justified. Until then we are better off without the extra complexity. Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Tested-by: Ondrej Zary <linux@rainbow-software.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-23 11:10:22 +01:00
/* ints[5] (use_tagged_queuing) is ignored */
/* ints[6] (use_pdma) is ignored */
if (ints[0] >= 7)
setup_toshiba_delay = ints[7];
return 1;
}
__setup("atascsi=", atari_scsi_setup);
#endif /* !MODULE */
static unsigned long atari_scsi_dma_setup(struct NCR5380_hostdata *hostdata,
void *data, unsigned long count,
int dir)
{
unsigned long addr = virt_to_phys(data);
dprintk(NDEBUG_DMA, "scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, dir = %d\n",
hostdata->host->host_no, data, addr, count, dir);
if (!IS_A_TT() && !STRAM_ADDR(addr)) {
/* If we have a non-DMAable address on a Falcon, use the dribble
* buffer; 'orig_addr' != 0 in the read case tells the interrupt
* handler to copy data from the dribble buffer to the originally
* wanted address.
*/
if (dir)
memcpy(atari_dma_buffer, data, count);
else
atari_dma_orig_addr = data;
addr = atari_dma_phys_buffer;
}
atari_dma_startaddr = addr; /* Needed for calculating residual later. */
/* Cache cleanup stuff: On writes, push any dirty cache out before sending
* it to the peripheral. (Must be done before DMA setup, since at least
* the ST-DMA begins to fill internal buffers right after setup. For
* reads, invalidate any cache, may be altered after DMA without CPU
* knowledge.
*
* ++roman: For the Medusa, there's no need at all for that cache stuff,
* because the hardware does bus snooping (fine!).
*/
dma_cache_maintenance(addr, count, dir);
if (IS_A_TT()) {
tt_scsi_dma.dma_ctrl = dir;
SCSI_DMA_WRITE_P(dma_addr, addr);
SCSI_DMA_WRITE_P(dma_cnt, count);
tt_scsi_dma.dma_ctrl = dir | 2;
} else { /* ! IS_A_TT */
/* set address */
SCSI_DMA_SETADR(addr);
/* toggle direction bit to clear FIFO and set DMA direction */
dir <<= 8;
st_dma.dma_mode_status = 0x90 | dir;
st_dma.dma_mode_status = 0x90 | (dir ^ 0x100);
st_dma.dma_mode_status = 0x90 | dir;
udelay(40);
/* On writes, round up the transfer length to the next multiple of 512
* (see also comment at atari_dma_xfer_len()). */
st_dma.fdc_acces_seccount = (count + (dir ? 511 : 0)) >> 9;
udelay(40);
st_dma.dma_mode_status = 0x10 | dir;
udelay(40);
/* need not restore value of dir, only boolean value is tested */
atari_dma_active = 1;
}
return count;
}
static inline int atari_scsi_dma_recv_setup(struct NCR5380_hostdata *hostdata,
unsigned char *data, int count)
{
return atari_scsi_dma_setup(hostdata, data, count, 0);
}
static inline int atari_scsi_dma_send_setup(struct NCR5380_hostdata *hostdata,
unsigned char *data, int count)
{
return atari_scsi_dma_setup(hostdata, data, count, 1);
}
static int atari_scsi_dma_residual(struct NCR5380_hostdata *hostdata)
{
return atari_dma_residual;
}
#define CMD_SURELY_BLOCK_MODE 0
#define CMD_SURELY_BYTE_MODE 1
#define CMD_MODE_UNKNOWN 2
static int falcon_classify_cmd(struct scsi_cmnd *cmd)
{
unsigned char opcode = cmd->cmnd[0];
if (opcode == READ_DEFECT_DATA || opcode == READ_LONG ||
opcode == READ_BUFFER)
return CMD_SURELY_BYTE_MODE;
else if (opcode == READ_6 || opcode == READ_10 ||
opcode == 0xa8 /* READ_12 */ || opcode == READ_REVERSE ||
opcode == RECOVER_BUFFERED_DATA) {
/* In case of a sequential-access target (tape), special care is
* needed here: The transfer is block-mode only if the 'fixed' bit is
* set! */
if (cmd->device->type == TYPE_TAPE && !(cmd->cmnd[1] & 1))
return CMD_SURELY_BYTE_MODE;
else
return CMD_SURELY_BLOCK_MODE;
} else
return CMD_MODE_UNKNOWN;
}
/* This function calculates the number of bytes that can be transferred via
* DMA. On the TT, this is arbitrary, but on the Falcon we have to use the
* ST-DMA chip. There are only multiples of 512 bytes possible and max.
* 255*512 bytes :-( This means also, that defining READ_OVERRUNS is not
* possible on the Falcon, since that would require to program the DMA for
* n*512 - atari_read_overrun bytes. But it seems that the Falcon doesn't have
* the overrun problem, so this question is academic :-)
*/
static int atari_scsi_dma_xfer_len(struct NCR5380_hostdata *hostdata,
struct scsi_cmnd *cmd)
{
int wanted_len = cmd->SCp.this_residual;
int possible_len, limit;
if (wanted_len < DMA_MIN_SIZE)
return 0;
if (IS_A_TT())
/* TT SCSI DMA can transfer arbitrary #bytes */
return wanted_len;
/* ST DMA chip is stupid -- only multiples of 512 bytes! (and max.
* 255*512 bytes, but this should be enough)
*
* ++roman: Aaargl! Another Falcon-SCSI problem... There are some commands
* that return a number of bytes which cannot be known beforehand. In this
* case, the given transfer length is an "allocation length". Now it
* can happen that this allocation length is a multiple of 512 bytes and
* the DMA is used. But if not n*512 bytes really arrive, some input data
* will be lost in the ST-DMA's FIFO :-( Thus, we have to distinguish
* between commands that do block transfers and those that do byte
* transfers. But this isn't easy... there are lots of vendor specific
* commands, and the user can issue any command via the
* SCSI_IOCTL_SEND_COMMAND.
*
* The solution: We classify SCSI commands in 1) surely block-mode cmd.s,
* 2) surely byte-mode cmd.s and 3) cmd.s with unknown mode. In case 1)
* and 3), the thing to do is obvious: allow any number of blocks via DMA
* or none. In case 2), we apply some heuristic: Byte mode is assumed if
* the transfer (allocation) length is < 1024, hoping that no cmd. not
* explicitly known as byte mode have such big allocation lengths...
* BTW, all the discussion above applies only to reads. DMA writes are
* unproblematic anyways, since the targets aborts the transfer after
* receiving a sufficient number of bytes.
*
* Another point: If the transfer is from/to an non-ST-RAM address, we
* use the dribble buffer and thus can do only STRAM_BUFFER_SIZE bytes.
*/
if (cmd->sc_data_direction == DMA_TO_DEVICE) {
/* Write operation can always use the DMA, but the transfer size must
* be rounded up to the next multiple of 512 (atari_dma_setup() does
* this).
*/
possible_len = wanted_len;
} else {
/* Read operations: if the wanted transfer length is not a multiple of
* 512, we cannot use DMA, since the ST-DMA cannot split transfers
* (no interrupt on DMA finished!)
*/
if (wanted_len & 0x1ff)
possible_len = 0;
else {
/* Now classify the command (see above) and decide whether it is
* allowed to do DMA at all */
switch (falcon_classify_cmd(cmd)) {
case CMD_SURELY_BLOCK_MODE:
possible_len = wanted_len;
break;
case CMD_SURELY_BYTE_MODE:
possible_len = 0; /* DMA prohibited */
break;
case CMD_MODE_UNKNOWN:
default:
/* For unknown commands assume block transfers if the transfer
* size/allocation length is >= 1024 */
possible_len = (wanted_len < 1024) ? 0 : wanted_len;
break;
}
}
}
/* Last step: apply the hard limit on DMA transfers */
limit = (atari_dma_buffer && !STRAM_ADDR(virt_to_phys(cmd->SCp.ptr))) ?
STRAM_BUFFER_SIZE : 255*512;
if (possible_len > limit)
possible_len = limit;
if (possible_len != wanted_len)
dprintk(NDEBUG_DMA, "DMA transfer now %d bytes instead of %d\n",
possible_len, wanted_len);
return possible_len;
}
/* NCR5380 register access functions
*
* There are separate functions for TT and Falcon, because the access
* methods are quite different. The calling macros NCR5380_read and
* NCR5380_write call these functions via function pointers.
*/
static u8 atari_scsi_tt_reg_read(unsigned int reg)
{
return tt_scsi_regp[reg * 2];
}
static void atari_scsi_tt_reg_write(unsigned int reg, u8 value)
{
tt_scsi_regp[reg * 2] = value;
}
static u8 atari_scsi_falcon_reg_read(unsigned int reg)
{
unsigned long flags;
u8 result;
reg += 0x88;
local_irq_save(flags);
dma_wd.dma_mode_status = (u_short)reg;
result = (u8)dma_wd.fdc_acces_seccount;
local_irq_restore(flags);
return result;
}
static void atari_scsi_falcon_reg_write(unsigned int reg, u8 value)
{
unsigned long flags;
reg += 0x88;
local_irq_save(flags);
dma_wd.dma_mode_status = (u_short)reg;
dma_wd.fdc_acces_seccount = (u_short)value;
local_irq_restore(flags);
}
#include "NCR5380.c"
static int atari_scsi_bus_reset(struct scsi_cmnd *cmd)
{
int rv;
unsigned long flags;
local_irq_save(flags);
/* Abort a maybe active DMA transfer */
if (IS_A_TT()) {
tt_scsi_dma.dma_ctrl = 0;
} else {
if (stdma_is_locked_by(scsi_falcon_intr))
st_dma.dma_mode_status = 0x90;
atari_dma_active = 0;
atari_dma_orig_addr = NULL;
}
rv = NCR5380_bus_reset(cmd);
/* The 5380 raises its IRQ line while _RST is active but the ST DMA
* "lock" has been released so this interrupt may end up handled by
* floppy or IDE driver (if one of them holds the lock). The NCR5380
* interrupt flag has been cleared already.
*/
local_irq_restore(flags);
return rv;
}
#define DRV_MODULE_NAME "atari_scsi"
#define PFX DRV_MODULE_NAME ": "
static struct scsi_host_template atari_scsi_template = {
.module = THIS_MODULE,
.proc_name = DRV_MODULE_NAME,
.name = "Atari native SCSI",
.info = atari_scsi_info,
.queuecommand = atari_scsi_queue_command,
.eh_abort_handler = atari_scsi_abort,
.eh_bus_reset_handler = atari_scsi_bus_reset,
.this_id = 7,
.cmd_per_lun = 2,
.use_clustering = DISABLE_CLUSTERING,
.cmd_size = NCR5380_CMD_SIZE,
};
static int __init atari_scsi_probe(struct platform_device *pdev)
{
struct Scsi_Host *instance;
int error;
struct resource *irq;
int host_flags = 0;
irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!irq)
return -ENODEV;
if (ATARIHW_PRESENT(TT_SCSI)) {
atari_scsi_reg_read = atari_scsi_tt_reg_read;
atari_scsi_reg_write = atari_scsi_tt_reg_write;
} else {
atari_scsi_reg_read = atari_scsi_falcon_reg_read;
atari_scsi_reg_write = atari_scsi_falcon_reg_write;
}
if (ATARIHW_PRESENT(TT_SCSI)) {
atari_scsi_template.can_queue = 16;
atari_scsi_template.sg_tablesize = SG_ALL;
} else {
atari_scsi_template.can_queue = 1;
atari_scsi_template.sg_tablesize = SG_NONE;
}
if (setup_can_queue > 0)
atari_scsi_template.can_queue = setup_can_queue;
if (setup_cmd_per_lun > 0)
atari_scsi_template.cmd_per_lun = setup_cmd_per_lun;
/* Leave sg_tablesize at 0 on a Falcon! */
if (ATARIHW_PRESENT(TT_SCSI) && setup_sg_tablesize >= 0)
atari_scsi_template.sg_tablesize = setup_sg_tablesize;
if (setup_hostid >= 0) {
atari_scsi_template.this_id = setup_hostid & 7;
} else {
/* Test if a host id is set in the NVRam */
if (ATARIHW_PRESENT(TT_CLK) && nvram_check_checksum()) {
unsigned char b = nvram_read_byte(16);
/* Arbitration enabled? (for TOS)
* If yes, use configured host ID
*/
if (b & 0x80)
atari_scsi_template.this_id = b & 7;
}
}
/* If running on a Falcon and if there's TT-Ram (i.e., more than one
* memory block, since there's always ST-Ram in a Falcon), then
* allocate a STRAM_BUFFER_SIZE byte dribble buffer for transfers
* from/to alternative Ram.
*/
if (ATARIHW_PRESENT(ST_SCSI) && !ATARIHW_PRESENT(EXTD_DMA) &&
m68k_num_memory > 1) {
atari_dma_buffer = atari_stram_alloc(STRAM_BUFFER_SIZE, "SCSI");
if (!atari_dma_buffer) {
pr_err(PFX "can't allocate ST-RAM double buffer\n");
return -ENOMEM;
}
atari_dma_phys_buffer = atari_stram_to_phys(atari_dma_buffer);
atari_dma_orig_addr = NULL;
}
instance = scsi_host_alloc(&atari_scsi_template,
sizeof(struct NCR5380_hostdata));
if (!instance) {
error = -ENOMEM;
goto fail_alloc;
}
instance->irq = irq->start;
host_flags |= IS_A_TT() ? 0 : FLAG_LATE_DMA_SETUP;
host_flags |= setup_toshiba_delay > 0 ? FLAG_TOSHIBA_DELAY : 0;
error = NCR5380_init(instance, host_flags);
if (error)
goto fail_init;
if (IS_A_TT()) {
error = request_irq(instance->irq, scsi_tt_intr, 0,
"NCR5380", instance);
if (error) {
pr_err(PFX "request irq %d failed, aborting\n",
instance->irq);
goto fail_irq;
}
tt_mfp.active_edge |= 0x80; /* SCSI int on L->H */
tt_scsi_dma.dma_ctrl = 0;
atari_dma_residual = 0;
/* While the read overruns (described by Drew Eckhardt in
* NCR5380.c) never happened on TTs, they do in fact on the
* Medusa (This was the cause why SCSI didn't work right for
* so long there.) Since handling the overruns slows down
* a bit, I turned the #ifdef's into a runtime condition.
*
* In principle it should be sufficient to do max. 1 byte with
* PIO, but there is another problem on the Medusa with the DMA
* rest data register. So read_overruns is currently set
* to 4 to avoid having transfers that aren't a multiple of 4.
* If the rest data bug is fixed, this can be lowered to 1.
*/
if (MACH_IS_MEDUSA) {
struct NCR5380_hostdata *hostdata =
shost_priv(instance);
hostdata->read_overruns = 4;
}
} else {
/* Nothing to do for the interrupt: the ST-DMA is initialized
* already.
*/
atari_dma_residual = 0;
atari_dma_active = 0;
atari_dma_stram_mask = (ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000
: 0xff000000);
}
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 (IS_A_TT())
free_irq(instance->irq, instance);
fail_irq:
NCR5380_exit(instance);
fail_init:
scsi_host_put(instance);
fail_alloc:
if (atari_dma_buffer)
atari_stram_free(atari_dma_buffer);
return error;
}
static int __exit atari_scsi_remove(struct platform_device *pdev)
{
struct Scsi_Host *instance = platform_get_drvdata(pdev);
scsi_remove_host(instance);
if (IS_A_TT())
free_irq(instance->irq, instance);
NCR5380_exit(instance);
scsi_host_put(instance);
if (atari_dma_buffer)
atari_stram_free(atari_dma_buffer);
return 0;
}
static struct platform_driver atari_scsi_driver = {
.remove = __exit_p(atari_scsi_remove),
.driver = {
.name = DRV_MODULE_NAME,
},
};
module_platform_driver_probe(atari_scsi_driver, atari_scsi_probe);
MODULE_ALIAS("platform:" DRV_MODULE_NAME);
MODULE_LICENSE("GPL");