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Diffstat (limited to 'drivers/scsi/atari_scsi.c')
| -rw-r--r-- | drivers/scsi/atari_scsi.c | 1163 |
1 files changed, 1163 insertions, 0 deletions
diff --git a/drivers/scsi/atari_scsi.c b/drivers/scsi/atari_scsi.c new file mode 100644 index 00000000000..af8adb629b3 --- /dev/null +++ b/drivers/scsi/atari_scsi.c @@ -0,0 +1,1163 @@ +/* + * 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: */ +/* ---------------------- */ +/* */ +/* Since the Falcon SCSI uses the ST-DMA chip, that is shared among */ +/* several device drivers, locking and unlocking the access to this */ +/* chip is required. But locking is not possible from an interrupt, */ +/* since it puts the process to sleep if the lock is not available. */ +/* This prevents "late" locking of the DMA chip, i.e. locking it just */ +/* before using it, since in case of disconnection-reconnection */ +/* commands, the DMA is started from the reselection interrupt. */ +/* */ +/* Two possible schemes for ST-DMA-locking would be: */ +/* 1) The lock is taken for each command separately and disconnecting */ +/* is forbidden (i.e. can_queue = 1). */ +/* 2) The DMA chip is locked when the first command comes in and */ +/* released when the last command is finished and all queues are */ +/* empty. */ +/* The first alternative would result in bad performance, since the */ +/* interleaving of commands would not be used. The second is unfair to */ +/* other drivers using the ST-DMA, because the queues will seldom be */ +/* totally empty if there is a lot of disk traffic. */ +/* */ +/* For this reasons I decided to employ a more elaborate scheme: */ +/* - First, we give up the lock every time we can (for fairness), this */ +/* means every time a command finishes and there are no other commands */ +/* on the disconnected queue. */ +/* - If there are others waiting to lock the DMA chip, we stop */ +/* issuing commands, i.e. moving them onto the issue queue. */ +/* Because of that, the disconnected queue will run empty in a */ +/* while. Instead we go to sleep on a 'fairness_queue'. */ +/* - If the lock is released, all processes waiting on the fairness */ +/* queue will be woken. The first of them tries to re-lock the DMA, */ +/* the others wait for the first to finish this task. After that, */ +/* they can all run on and do their commands... */ +/* This sounds complicated (and it is it :-(), but it seems to be a */ +/* good compromise between fairness and performance: As long as no one */ +/* else wants to work with the ST-DMA chip, SCSI can go along as */ +/* usual. If now someone else comes, this behaviour is changed to a */ +/* "fairness mode": just already initiated commands are finished and */ +/* then the lock is released. The other one waiting will probably win */ +/* the race for locking the DMA, since it was waiting for longer. And */ +/* after it has finished, SCSI can go ahead again. Finally: I hope I */ +/* have not produced any deadlock possibilities! */ +/* */ +/**************************************************************************/ + + + +#include <linux/config.h> +#include <linux/module.h> + +#define NDEBUG (0) + +#define NDEBUG_ABORT 0x800000 +#define NDEBUG_TAGS 0x1000000 +#define NDEBUG_MERGING 0x2000000 + +#define AUTOSENSE +/* For the Atari version, use only polled IO or REAL_DMA */ +#define REAL_DMA +/* Support tagged queuing? (on devices that are able to... :-) */ +#define SUPPORT_TAGS +#define MAX_TAGS 32 + +#include <linux/types.h> +#include <linux/stddef.h> +#include <linux/ctype.h> +#include <linux/delay.h> +#include <linux/mm.h> +#include <linux/blkdev.h> +#include <linux/sched.h> +#include <linux/interrupt.h> +#include <linux/init.h> +#include <linux/nvram.h> +#include <linux/bitops.h> + +#include <asm/setup.h> +#include <asm/atarihw.h> +#include <asm/atariints.h> +#include <asm/page.h> +#include <asm/pgtable.h> +#include <asm/irq.h> +#include <asm/traps.h> + +#include "scsi.h" +#include <scsi/scsi_host.h> +#include "atari_scsi.h" +#include "NCR5380.h" +#include <asm/atari_stdma.h> +#include <asm/atari_stram.h> +#include <asm/io.h> + +#include <linux/stat.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 inline void ENABLE_IRQ(void) +{ + if (IS_A_TT()) + atari_enable_irq(IRQ_TT_MFP_SCSI); + else + atari_enable_irq(IRQ_MFP_FSCSI); +} + +static inline void DISABLE_IRQ(void) +{ + if (IS_A_TT()) + atari_disable_irq(IRQ_TT_MFP_SCSI); + else + atari_disable_irq(IRQ_MFP_FSCSI); +} + + +#define HOSTDATA_DMALEN (((struct NCR5380_hostdata *) \ + (atari_scsi_host->hostdata))->dma_len) + +/* Time (in jiffies) to wait after a reset; the SCSI standard calls for 250ms, + * we usually do 0.5s to be on the safe side. But Toshiba CD-ROMs once more + * need ten times the standard value... */ +#ifndef CONFIG_ATARI_SCSI_TOSHIBA_DELAY +#define AFTER_RESET_DELAY (HZ/2) +#else +#define AFTER_RESET_DELAY (5*HZ/2) +#endif + +/***************************** Prototypes *****************************/ + +#ifdef REAL_DMA +static int scsi_dma_is_ignored_buserr( unsigned char dma_stat ); +static void atari_scsi_fetch_restbytes( void ); +static long atari_scsi_dma_residual( struct Scsi_Host *instance ); +static int falcon_classify_cmd( Scsi_Cmnd *cmd ); +static unsigned long atari_dma_xfer_len( unsigned long wanted_len, + Scsi_Cmnd *cmd, int write_flag ); +#endif +static irqreturn_t scsi_tt_intr( int irq, void *dummy, struct pt_regs *fp); +static irqreturn_t scsi_falcon_intr( int irq, void *dummy, struct pt_regs *fp); +static void falcon_release_lock_if_possible( struct NCR5380_hostdata * + hostdata ); +static void falcon_get_lock( void ); +#ifdef CONFIG_ATARI_SCSI_RESET_BOOT +static void atari_scsi_reset_boot( void ); +#endif +static unsigned char atari_scsi_tt_reg_read( unsigned char reg ); +static void atari_scsi_tt_reg_write( unsigned char reg, unsigned char value); +static unsigned char atari_scsi_falcon_reg_read( unsigned char reg ); +static void atari_scsi_falcon_reg_write( unsigned char reg, unsigned char value ); + +/************************* End of Prototypes **************************/ + + +static struct Scsi_Host *atari_scsi_host = NULL; +static unsigned char (*atari_scsi_reg_read)( unsigned char reg ); +static void (*atari_scsi_reg_write)( unsigned char reg, unsigned char value ); + +#ifdef REAL_DMA +static unsigned long atari_dma_residual, atari_dma_startaddr; +static short atari_dma_active; +/* pointer to the dribble buffer */ +static char *atari_dma_buffer = NULL; +/* 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) +/* number of bytes to cut from a transfer to handle NCR overruns */ +static int atari_read_overruns = 0; +#endif + +static int setup_can_queue = -1; +MODULE_PARM(setup_can_queue, "i"); +static int setup_cmd_per_lun = -1; +MODULE_PARM(setup_cmd_per_lun, "i"); +static int setup_sg_tablesize = -1; +MODULE_PARM(setup_sg_tablesize, "i"); +#ifdef SUPPORT_TAGS +static int setup_use_tagged_queuing = -1; +MODULE_PARM(setup_use_tagged_queuing, "i"); +#endif +static int setup_hostid = -1; +MODULE_PARM(setup_hostid, "i"); + + +#if defined(CONFIG_TT_DMA_EMUL) +#include "atari_dma_emul.c" +#endif + +#if defined(REAL_DMA) + +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 ); +} + + +#if 0 +/* Dead code... wasn't called anyway :-) and causes some trouble, because at + * end-of-DMA, both SCSI ints are triggered simultaneously, so the NCR int has + * to clear the DMA int pending bit before it allows other level 6 interrupts. + */ +static void scsi_dma_buserr (int irq, void *dummy, struct pt_regs *fp) +{ + unsigned char dma_stat = tt_scsi_dma.dma_ctrl; + + /* Don't do anything if a NCR interrupt is pending. Probably it's just + * masked... */ + if (atari_irq_pending( IRQ_TT_MFP_SCSI )) + return; + + printk("Bad SCSI DMA interrupt! dma_addr=0x%08lx dma_stat=%02x dma_cnt=%08lx\n", + SCSI_DMA_READ_P(dma_addr), dma_stat, SCSI_DMA_READ_P(dma_cnt)); + if (dma_stat & 0x80) { + if (!scsi_dma_is_ignored_buserr( dma_stat )) + printk( "SCSI DMA bus error -- bad DMA programming!\n" ); + } + else { + /* Under normal circumstances we never should get to this point, + * since both interrupts are triggered simultaneously and the 5380 + * int has higher priority. When this irq is handled, that DMA + * interrupt is cleared. So a warning message is printed here. + */ + printk( "SCSI DMA intr ?? -- this shouldn't happen!\n" ); + } +} +#endif + +#endif + + +static irqreturn_t scsi_tt_intr (int irq, void *dummy, struct pt_regs *fp) +{ +#ifdef REAL_DMA + int dma_stat; + + dma_stat = tt_scsi_dma.dma_ctrl; + + INT_PRINTK("scsi%d: NCR5380 interrupt, DMA status = %02x\n", + atari_scsi_host->host_no, 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_DMALEN - (SCSI_DMA_READ_P( dma_addr ) - + atari_dma_startaddr); + + DMA_PRINTK("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) { + DMA_PRINTK("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; + } + +#endif /* REAL_DMA */ + + NCR5380_intr (0, 0, 0); + +#if 0 + /* To be sure the int is not masked */ + atari_enable_irq( IRQ_TT_MFP_SCSI ); +#endif + return IRQ_HANDLED; +} + + +static irqreturn_t scsi_falcon_intr (int irq, void *dummy, struct pt_regs *fp) +{ +#ifdef REAL_DMA + 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_DMALEN - transferred; + DMA_PRINTK("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_DMALEN - atari_dma_residual); + atari_dma_orig_addr = NULL; + } + +#endif /* REAL_DMA */ + + NCR5380_intr (0, 0, 0); + return IRQ_HANDLED; +} + + +#ifdef REAL_DMA +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; + DMA_PRINTK("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); + DMA_PRINTK(" = virt addr %p\n", dst); + for (src = (char *)&tt_scsi_dma.dma_restdata; nr != 0; --nr) + *dst++ = *src++; + } +} +#endif /* REAL_DMA */ + + +static int falcon_got_lock = 0; +static DECLARE_WAIT_QUEUE_HEAD(falcon_fairness_wait); +static int falcon_trying_lock = 0; +static DECLARE_WAIT_QUEUE_HEAD(falcon_try_wait); +static int falcon_dont_release = 0; + +/* This function releases the lock on the DMA chip if there is no + * connected command and the disconnected queue is empty. On + * releasing, instances of falcon_get_lock are awoken, that put + * themselves to sleep for fairness. They can now try to get the lock + * again (but others waiting longer more probably will win). + */ + +static void +falcon_release_lock_if_possible( struct NCR5380_hostdata * hostdata ) +{ + unsigned long flags; + + if (IS_A_TT()) return; + + local_irq_save(flags); + + if (falcon_got_lock && + !hostdata->disconnected_queue && + !hostdata->issue_queue && + !hostdata->connected) { + + if (falcon_dont_release) { +#if 0 + printk("WARNING: Lock release not allowed. Ignored\n"); +#endif + local_irq_restore(flags); + return; + } + falcon_got_lock = 0; + stdma_release(); + wake_up( &falcon_fairness_wait ); + } + + local_irq_restore(flags); +} + +/* 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 wait on 'falcon_fairness_queue'. We will be + * waked up when the DMA is unlocked by some SCSI interrupt. After that + * we try to get the lock again. + * But we must be prepared that more than one instance of + * falcon_get_lock() is waiting on the fairness queue. They should not + * try all at once to call stdma_lock(), one is enough! For that, the + * first one sets 'falcon_trying_lock', others that see that variable + * set wait on the queue 'falcon_try_wait'. + * Complicated, complicated.... Sigh... + */ + +static void falcon_get_lock( void ) +{ + unsigned long flags; + + if (IS_A_TT()) return; + + local_irq_save(flags); + + while( !in_interrupt() && falcon_got_lock && stdma_others_waiting() ) + sleep_on( &falcon_fairness_wait ); + + while (!falcon_got_lock) { + if (in_interrupt()) + panic( "Falcon SCSI hasn't ST-DMA lock in interrupt" ); + if (!falcon_trying_lock) { + falcon_trying_lock = 1; + stdma_lock(scsi_falcon_intr, NULL); + falcon_got_lock = 1; + falcon_trying_lock = 0; + wake_up( &falcon_try_wait ); + } + else { + sleep_on( &falcon_try_wait ); + } + } + + local_irq_restore(flags); + if (!falcon_got_lock) + panic("Falcon SCSI: someone stole the lock :-(\n"); +} + + +/* This is the wrapper function for NCR5380_queue_command(). It just + * tries to get the lock on the ST-DMA (see above) and then calls the + * original function. + */ + +#if 0 +int atari_queue_command (Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *)) +{ + /* falcon_get_lock(); + * ++guenther: moved to NCR5380_queue_command() to prevent + * race condition, see there for an explanation. + */ + return( NCR5380_queue_command( cmd, done ) ); +} +#endif + + +int atari_scsi_detect (Scsi_Host_Template *host) +{ + static int called = 0; + struct Scsi_Host *instance; + + if (!MACH_IS_ATARI || + (!ATARIHW_PRESENT(ST_SCSI) && !ATARIHW_PRESENT(TT_SCSI)) || + called) + return( 0 ); + + host->proc_name = "Atari"; + + atari_scsi_reg_read = IS_A_TT() ? atari_scsi_tt_reg_read : + atari_scsi_falcon_reg_read; + atari_scsi_reg_write = IS_A_TT() ? atari_scsi_tt_reg_write : + atari_scsi_falcon_reg_write; + + /* setup variables */ + host->can_queue = + (setup_can_queue > 0) ? setup_can_queue : + IS_A_TT() ? ATARI_TT_CAN_QUEUE : ATARI_FALCON_CAN_QUEUE; + host->cmd_per_lun = + (setup_cmd_per_lun > 0) ? setup_cmd_per_lun : + IS_A_TT() ? ATARI_TT_CMD_PER_LUN : ATARI_FALCON_CMD_PER_LUN; + /* Force sg_tablesize to 0 on a Falcon! */ + host->sg_tablesize = + !IS_A_TT() ? ATARI_FALCON_SG_TABLESIZE : + (setup_sg_tablesize >= 0) ? setup_sg_tablesize : ATARI_TT_SG_TABLESIZE; + + if (setup_hostid >= 0) + host->this_id = setup_hostid; + else { + /* use 7 as default */ + host->this_id = 7; + /* Test if a host id is set in the NVRam */ + if (ATARIHW_PRESENT(TT_CLK) && nvram_check_checksum()) { + unsigned char b = nvram_read_byte( 14 ); + /* Arbitration enabled? (for TOS) If yes, use configured host ID */ + if (b & 0x80) + host->this_id = b & 7; + } + } + +#ifdef SUPPORT_TAGS + if (setup_use_tagged_queuing < 0) + setup_use_tagged_queuing = DEFAULT_USE_TAGGED_QUEUING; +#endif +#ifdef REAL_DMA + /* 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 (MACH_IS_ATARI && 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) { + printk( KERN_ERR "atari_scsi_detect: can't allocate ST-RAM " + "double buffer\n" ); + return( 0 ); + } + atari_dma_phys_buffer = virt_to_phys( atari_dma_buffer ); + atari_dma_orig_addr = 0; + } +#endif + instance = scsi_register (host, sizeof (struct NCR5380_hostdata)); + if(instance == NULL) + { + atari_stram_free(atari_dma_buffer); + atari_dma_buffer = 0; + return 0; + } + atari_scsi_host = instance; + /* Set irq to 0, to avoid that the mid-level code disables our interrupt + * during queue_command calls. This is completely unnecessary, and even + * worse causes bad problems on the Falcon, where the int is shared with + * IDE and floppy! */ + instance->irq = 0; + +#ifdef CONFIG_ATARI_SCSI_RESET_BOOT + atari_scsi_reset_boot(); +#endif + NCR5380_init (instance, 0); + + if (IS_A_TT()) { + + /* This int is actually "pseudo-slow", i.e. it acts like a slow + * interrupt after having cleared the pending flag for the DMA + * interrupt. */ + if (request_irq(IRQ_TT_MFP_SCSI, scsi_tt_intr, IRQ_TYPE_SLOW, + "SCSI NCR5380", scsi_tt_intr)) { + printk(KERN_ERR "atari_scsi_detect: cannot allocate irq %d, aborting",IRQ_TT_MFP_SCSI); + scsi_unregister(atari_scsi_host); + atari_stram_free(atari_dma_buffer); + atari_dma_buffer = 0; + return 0; + } + tt_mfp.active_edge |= 0x80; /* SCSI int on L->H */ +#ifdef REAL_DMA + tt_scsi_dma.dma_ctrl = 0; + atari_dma_residual = 0; +#ifdef CONFIG_TT_DMA_EMUL + if (MACH_IS_HADES) { + if (request_irq(IRQ_AUTO_2, hades_dma_emulator, + IRQ_TYPE_PRIO, "Hades DMA emulator", + hades_dma_emulator)) { + printk(KERN_ERR "atari_scsi_detect: cannot allocate irq %d, aborting (MACH_IS_HADES)",IRQ_AUTO_2); + free_irq(IRQ_TT_MFP_SCSI, scsi_tt_intr); + scsi_unregister(atari_scsi_host); + atari_stram_free(atari_dma_buffer); + atari_dma_buffer = 0; + return 0; + } + } +#endif + if (MACH_IS_MEDUSA || MACH_IS_HADES) { + /* 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 'atari_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. + */ + atari_read_overruns = 4; + } +#endif /*REAL_DMA*/ + } + else { /* ! IS_A_TT */ + + /* Nothing to do for the interrupt: the ST-DMA is initialized + * already by atari_init_INTS() + */ + +#ifdef REAL_DMA + atari_dma_residual = 0; + atari_dma_active = 0; + atari_dma_stram_mask = (ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000 + : 0xff000000); +#endif + } + + printk(KERN_INFO "scsi%d: options CAN_QUEUE=%d CMD_PER_LUN=%d SCAT-GAT=%d " +#ifdef SUPPORT_TAGS + "TAGGED-QUEUING=%s " +#endif + "HOSTID=%d", + instance->host_no, instance->hostt->can_queue, + instance->hostt->cmd_per_lun, + instance->hostt->sg_tablesize, +#ifdef SUPPORT_TAGS + setup_use_tagged_queuing ? "yes" : "no", +#endif + instance->hostt->this_id ); + NCR5380_print_options (instance); + printk ("\n"); + + called = 1; + return( 1 ); +} + +#ifdef MODULE +int atari_scsi_release (struct Scsi_Host *sh) +{ + if (IS_A_TT()) + free_irq(IRQ_TT_MFP_SCSI, scsi_tt_intr); + if (atari_dma_buffer) + atari_stram_free (atari_dma_buffer); + return 1; +} +#endif + +void __init atari_scsi_setup(char *str, int *ints) +{ + /* Format of atascsi parameter is: + * atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags> + * Defaults depend on TT or Falcon, hostid determined at run time. + * Negative values mean don't change. + */ + + if (ints[0] < 1) { + printk( "atari_scsi_setup: no arguments!\n" ); + return; + } + + if (ints[0] >= 1) { + if (ints[1] > 0) + /* no limits on this, just > 0 */ + setup_can_queue = ints[1]; + } + if (ints[0] >= 2) { + if (ints[2] > 0) + setup_cmd_per_lun = ints[2]; + } + if (ints[0] >= 3) { + if (ints[3] >= 0) { + setup_sg_tablesize = ints[3]; + /* Must be <= SG_ALL (255) */ + if (setup_sg_tablesize > SG_ALL) + setup_sg_tablesize = SG_ALL; + } + } + if (ints[0] >= 4) { + /* Must be between 0 and 7 */ + if (ints[4] >= 0 && ints[4] <= 7) + setup_hostid = ints[4]; + else if (ints[4] > 7) + printk( "atari_scsi_setup: invalid host ID %d !\n", ints[4] ); + } +#ifdef SUPPORT_TAGS + if (ints[0] >= 5) { + if (ints[5] >= 0) + setup_use_tagged_queuing = !!ints[5]; + } +#endif +} + +int atari_scsi_bus_reset(Scsi_Cmnd *cmd) +{ + int rv; + struct NCR5380_hostdata *hostdata = + (struct NCR5380_hostdata *)cmd->device->host->hostdata; + + /* For doing the reset, SCSI interrupts must be disabled first, + * since the 5380 raises its IRQ line while _RST is active and we + * can't disable interrupts completely, since we need the timer. + */ + /* And abort a maybe active DMA transfer */ + if (IS_A_TT()) { + atari_turnoff_irq( IRQ_TT_MFP_SCSI ); +#ifdef REAL_DMA + tt_scsi_dma.dma_ctrl = 0; +#endif /* REAL_DMA */ + } + else { + atari_turnoff_irq( IRQ_MFP_FSCSI ); +#ifdef REAL_DMA + st_dma.dma_mode_status = 0x90; + atari_dma_active = 0; + atari_dma_orig_addr = NULL; +#endif /* REAL_DMA */ + } + + rv = NCR5380_bus_reset(cmd); + + /* Re-enable ints */ + if (IS_A_TT()) { + atari_turnon_irq( IRQ_TT_MFP_SCSI ); + } + else { + atari_turnon_irq( IRQ_MFP_FSCSI ); + } + if ((rv & SCSI_RESET_ACTION) == SCSI_RESET_SUCCESS) + falcon_release_lock_if_possible(hostdata); + + return( rv ); +} + + +#ifdef CONFIG_ATARI_SCSI_RESET_BOOT +static void __init atari_scsi_reset_boot(void) +{ + unsigned long end; + + /* + * Do a SCSI reset to clean up the bus during initialization. No messing + * with the queues, interrupts, or locks necessary here. + */ + + printk( "Atari SCSI: resetting the SCSI bus..." ); + + /* get in phase */ + NCR5380_write( TARGET_COMMAND_REG, + PHASE_SR_TO_TCR( NCR5380_read(STATUS_REG) )); + + /* assert RST */ + NCR5380_write( INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST ); + /* The min. reset hold time is 25us, so 40us should be enough */ + udelay( 50 ); + /* reset RST and interrupt */ + NCR5380_write( INITIATOR_COMMAND_REG, ICR_BASE ); + NCR5380_read( RESET_PARITY_INTERRUPT_REG ); + + end = jiffies + AFTER_RESET_DELAY; + while (time_before(jiffies, end)) + barrier(); + + printk( " done\n" ); +} +#endif + + +const char * atari_scsi_info (struct Scsi_Host *host) +{ + /* atari_scsi_detect() is verbose enough... */ + static const char string[] = "Atari native SCSI"; + return string; +} + + +#if defined(REAL_DMA) + +unsigned long atari_scsi_dma_setup( struct Scsi_Host *instance, void *data, + unsigned long count, int dir ) +{ + unsigned long addr = virt_to_phys( data ); + + DMA_PRINTK("scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, " + "dir = %d\n", instance->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 (count == 0) + printk(KERN_NOTICE "SCSI warning: DMA programmed for 0 bytes !\n"); + + 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 long atari_scsi_dma_residual( struct Scsi_Host *instance ) +{ + 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( 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 unsigned long atari_dma_xfer_len( unsigned long wanted_len, + Scsi_Cmnd *cmd, + int write_flag ) +{ + unsigned long possible_len, limit; +#ifndef CONFIG_TT_DMA_EMUL + if (MACH_IS_HADES) + /* Hades has no SCSI DMA at all :-( Always force use of PIO */ + return( 0 ); +#endif + 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 (write_flag) { + /* 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) + DMA_PRINTK("Sorry, must cut DMA transfer size to %ld bytes " + "instead of %ld\n", possible_len, wanted_len); + + return( possible_len ); +} + + +#endif /* REAL_DMA */ + + +/* 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 unsigned char atari_scsi_tt_reg_read( unsigned char reg ) +{ + return( tt_scsi_regp[reg * 2] ); +} + +static void atari_scsi_tt_reg_write( unsigned char reg, unsigned char value ) +{ + tt_scsi_regp[reg * 2] = value; +} + +static unsigned char atari_scsi_falcon_reg_read( unsigned char reg ) +{ + dma_wd.dma_mode_status= (u_short)(0x88 + reg); + return( (u_char)dma_wd.fdc_acces_seccount ); +} + +static void atari_scsi_falcon_reg_write( unsigned char reg, unsigned char value ) +{ + dma_wd.dma_mode_status = (u_short)(0x88 + reg); + dma_wd.fdc_acces_seccount = (u_short)value; +} + + +#include "atari_NCR5380.c" + +static Scsi_Host_Template driver_template = { + .proc_info = atari_scsi_proc_info, + .name = "Atari native SCSI", + .detect = atari_scsi_detect, + .release = atari_scsi_release, + .info = atari_scsi_info, + .queuecommand = atari_scsi_queue_command, + .eh_abort_handler = atari_scsi_abort, + .eh_bus_reset_handler = atari_scsi_bus_reset, + .can_queue = 0, /* initialized at run-time */ + .this_id = 0, /* initialized at run-time */ + .sg_tablesize = 0, /* initialized at run-time */ + .cmd_per_lun = 0, /* initialized at run-time */ + .use_clustering = DISABLE_CLUSTERING +}; + + +#include "scsi_module.c" + +MODULE_LICENSE("GPL"); |