mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
892 lines
26 KiB
892 lines
26 KiB
/* |
|
* atari_scsi.c -- Device dependent functions for the Atari generic SCSI port |
|
* |
|
* Copyright 1994 Roman Hodek <[email protected]> |
|
* |
|
* 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)) |
|
return 1; |
|
|
|
/* stdma_lock() may sleep which means it can't be used here */ |
|
return stdma_try_lock(scsi_falcon_intr, instance); |
|
} |
|
|
|
#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]; |
|
/* 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 = NCR5380_to_ncmd(cmd)->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(NCR5380_to_ncmd(cmd)->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_host_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_host_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_host_reset_handler = atari_scsi_host_reset, |
|
.this_id = 7, |
|
.cmd_per_lun = 2, |
|
.dma_boundary = PAGE_SIZE - 1, |
|
.cmd_size = sizeof(struct NCR5380_cmd), |
|
}; |
|
|
|
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 = 1; |
|
} |
|
|
|
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; |
|
|
|
/* Don't increase sg_tablesize on 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 if (IS_REACHABLE(CONFIG_NVRAM)) { |
|
/* Test if a host id is set in the NVRam */ |
|
if (ATARIHW_PRESENT(TT_CLK)) { |
|
unsigned char b; |
|
loff_t offset = 16; |
|
ssize_t count = nvram_read(&b, 1, &offset); |
|
|
|
/* Arbitration enabled? (for TOS) |
|
* If yes, use configured host ID |
|
*/ |
|
if ((count == 1) && (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_realnum_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");
|
|
|