patch-1.3.94 linux/drivers/scsi/atari_scsi.c
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- Lines: 1164
- Date:
Fri Apr 19 02:35:24 1996
- Orig file:
v1.3.93/linux/drivers/scsi/atari_scsi.c
- Orig date:
Thu Jan 1 02:00:00 1970
diff -u --recursive --new-file v1.3.93/linux/drivers/scsi/atari_scsi.c linux/drivers/scsi/atari_scsi.c
@@ -0,0 +1,1163 @@
+/*
+ * atari_scsi.c -- Device dependant 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 README.legal 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 everytime 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 */
+/* issueing 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 trys 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 noone */
+/* 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 (NDEBUG_DMA) */
+
+#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/blk.h>
+
+#include <asm/bootinfo.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 <asm/bitops.h>
+
+#include "scsi.h"
+#include "hosts.h"
+#include "atari_scsi.h"
+#include "NCR5380.h"
+#include "constants.h"
+#include <asm/atari_stdma.h>
+#include <asm/io.h>
+
+#include<linux/stat.h>
+
+struct proc_dir_entry proc_scsi_atari = {
+ PROC_SCSI_ATARI, 5, "Atari",
+ S_IFDIR | S_IRUGO | S_IXUGO, 2
+};
+
+#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 << 24) | \
+ ((unsigned long)tt_scsi_dma.elt##_hmd << 16) | \
+ ((unsigned long)tt_scsi_dma.elt##_lmd << 8) | \
+ (unsigned long)tt_scsi_dma.elt##_lo)
+
+
+#define SCSI_DMA_SETADR(adr) \
+ do { \
+ unsigned long __adr = (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(); \
+ } while(0)
+
+#define SCSI_DMA_GETADR() ({ \
+ 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(); \
+ __adr; \
+})
+
+#define ENABLE_IRQ() \
+ do { \
+ if (IS_A_TT()) \
+ atari_enable_irq( IRQ_TT_MFP_SCSI ); \
+ else \
+ atari_enable_irq( IRQ_MFP_FSCSI ); \
+ } while(0)
+
+#define DISABLE_IRQ() \
+ do { \
+ if (IS_A_TT()) \
+ atari_disable_irq( IRQ_TT_MFP_SCSI ); \
+ else \
+ atari_disable_irq( IRQ_MFP_FSCSI ); \
+ } while(0)
+
+
+#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 scsi_dma_buserr( int irq, struct pt_regs *fp, void *dummy);
+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 void scsi_tt_intr( int irq, struct pt_regs *fp, void *dummy);
+static void scsi_falcon_intr( int irq, struct pt_regs *fp, void *dummy);
+static void falcon_release_lock_if_possible( struct NCR5380_hostdata *
+ hostdata );
+static void falcon_get_lock( void );
+static void atari_scsi_reset_boot( void );
+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
+
+int setup_can_queue = -1;
+int setup_cmd_per_lun = -1;
+int setup_sg_tablesize = -1;
+#ifdef SUPPORT_TAGS
+int setup_use_tagged_queuing = -1;
+#endif
+int setup_hostid = -1;
+
+
+#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 < boot_info.num_memory; ++i ) {
+ end_addr = boot_info.memory[i].addr +
+ boot_info.memory[i].size;
+ if (end_addr <= addr && addr <= end_addr + 4)
+ return( 1 );
+ }
+ }
+ return( 0 );
+}
+
+
+static void scsi_dma_buserr (int irq, struct pt_regs *fp, void *dummy)
+{
+ 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
+
+
+static void scsi_tt_intr (int irq, struct pt_regs *fp, void *dummy)
+{
+ unsigned long flags;
+#ifdef REAL_DMA
+ int dma_stat;
+#endif
+
+ /* If we got this interrupt, we don't need the other one from the DMA any
+ * more. So clear it. */
+ atari_clear_pending_irq( IRQ_TT_MFP_SCSIDMA );
+ /* After this has been done, we can make this int handler "slow", i.e.
+ * mask the NCR int and lower the IPL, as a slow int would do (see
+ * arch/m68k/atari/ataints.c) */
+ atari_disable_irq( IRQ_TT_MFP_SCSI );
+ save_flags(flags);
+ flags &= 0xf8ff;
+ flags |= fp->sr & 0x0700;
+ restore_flags(flags);
+
+#ifdef REAL_DMA
+ dma_stat = tt_scsi_dma.dma_ctrl;
+
+#if (NDEBUG & NDEBUG_INTR)
+ printk("scsi%d: NCR5380 interrupt, DMA status = %02x\n",
+ atari_scsi_host->host_no, dma_stat & 0xff);
+#endif
+
+ /* Look if it was the DMA that has interrupted: First possibility
+ * is that a bus error occured...
+ */
+ if (dma_stat & 0x80) {
+ if (!scsi_dma_is_ignored_buserr( dma_stat )) {
+ printk( "SCSI DMA caused bus error near 0x%08lx\n",
+ SCSI_DMA_READ_P( dma_addr ));
+ panic( "SCSI DMA bus error -- bad DMA programming!" );
+ }
+ }
+
+ /* If the DMA is active but not finished, we have the the case
+ * that some other 5380 interrupt occured 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);
+#if (NDEBUG & NDEBUG_DMA)
+ printk( "SCSI DMA: There are %ld residual bytes.\n",
+ atari_dma_residual );
+#endif
+ 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) {
+#if (NDEBUG & NDEBUG_DMA)
+ printk("SCSI DMA: DMA bug corrected, difference %ld bytes\n",
+ 512 - (atari_dma_residual & 0x1ff));
+#endif
+ 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);
+
+ /* To be sure the int is not masked */
+ atari_enable_irq( IRQ_TT_MFP_SCSI );
+}
+
+
+static void scsi_falcon_intr (int irq, struct pt_regs *fp, void *dummy)
+{
+#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( "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( "SCSI DMA error: %ld bytes lost in ST-DMA fifo :-((\n",
+ transferred & 15 );
+
+ atari_dma_residual = HOSTDATA_DMALEN - transferred;
+#if (NDEBUG & NDEBUG_DMA)
+ printk( "SCSI DMA: There are %ld residual bytes.\n",
+ atari_dma_residual );
+#endif
+ }
+ 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, (void *)PTOV(atari_dma_startaddr),
+ HOSTDATA_DMALEN - atari_dma_residual );
+ atari_dma_orig_addr = NULL;
+ }
+
+#endif /* REAL_DMA */
+
+ NCR5380_intr (0, 0, 0);
+}
+
+
+#ifdef REAL_DMA
+static void atari_scsi_fetch_restbytes( void )
+{
+ int nr;
+ char *src, *dst;
+
+ /* fetch rest bytes in the DMA register */
+ dst = (char *)SCSI_DMA_READ_P( dma_addr );
+ if ((nr = ((long)dst & 3))) {
+ /* there are 'nr' bytes left for the last long address before the
+ DMA pointer */
+ dst = (char *)( (unsigned long)dst & ~3 );
+#if (NDEBUG & NDEBUG_DMA)
+ printk( "SCSI DMA: there are %d rest bytes for phys addr 0x%08lx",
+ nr, (long)dst );
+#endif
+ dst = (char *)PTOV(dst); /* The content of the DMA pointer
+ * is a physical address! */
+#if (NDEBUG & NDEBUG_DMA)
+ printk( " = virt addr 0x%08lx\n", (long)dst );
+#endif
+ for( src = (char *)&tt_scsi_dma.dma_restdata; nr > 0; --nr )
+ *dst++ = *src++;
+ }
+}
+#endif /* REAL_DMA */
+
+
+static int falcon_got_lock = 0;
+static struct wait_queue *falcon_fairness_wait = NULL;
+static int falcon_trying_lock = 0;
+static struct wait_queue *falcon_try_wait = NULL;
+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 oldflags;
+
+ if (IS_A_TT()) return;
+
+ save_flags(oldflags);
+ cli();
+
+ 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
+ restore_flags(oldflags);
+ return;
+ }
+ falcon_got_lock = 0;
+ stdma_release();
+ wake_up( &falcon_fairness_wait );
+ }
+
+ restore_flags(oldflags);
+}
+
+/* This function manages the locking of the ST-DMA.
+ * If the DMA isn't locked already for SCSI, it trys 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 oldflags;
+
+ if (IS_A_TT()) return;
+
+ save_flags(oldflags);
+ cli();
+
+ while( intr_count == 0 && falcon_got_lock && stdma_others_waiting() )
+ sleep_on( &falcon_fairness_wait );
+
+ while (!falcon_got_lock) {
+ if (intr_count > 0)
+ 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 );
+ }
+ }
+
+ restore_flags(oldflags);
+ if (!falcon_got_lock)
+ panic("Falcon SCSI: someone stole the lock :-(\n");
+}
+
+
+/* This is the wrapper function for NCR5380_queue_command(). It just
+ * trys 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
+
+
+#define RTC_READ(reg) \
+ ({ unsigned char __val; \
+ outb(reg,&tt_rtc.regsel); \
+ __val = tt_rtc.data; \
+ __val; \
+ })
+
+#define RTC_WRITE(reg,val) \
+ do { \
+ outb(reg,&tt_rtc.regsel); \
+ tt_rtc.data = (val); \
+ } while(0)
+
+
+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_dir = &proc_scsi_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)) {
+ unsigned char sum = 0, b;
+ int i;
+
+ /* Make checksum */
+ for( i = 14; i < 62; ++i )
+ sum += RTC_READ(i);
+
+ if (/* NV-Ram checksum valid? */
+ RTC_READ(62) == sum && RTC_READ(63) == ~sum &&
+ /* Arbitration enabled? (for TOS) */
+ (b = RTC_READ( 30 )) & 0x80) {
+ host->this_id = b & 7;
+ }
+ }
+ }
+
+#ifdef SUPPORT_TAGS
+ if (setup_use_tagged_queuing < 0)
+ setup_use_tagged_queuing = DEFAULT_USE_TAGGED_QUEUING;
+#endif
+
+ /* 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) && boot_info.num_memory > 1) {
+ atari_dma_buffer = scsi_init_malloc(STRAM_BUFFER_SIZE,
+ GFP_ATOMIC | GFP_DMA);
+ atari_dma_phys_buffer = VTOP( atari_dma_buffer );
+ atari_dma_orig_addr = 0;
+ }
+
+ instance = scsi_register (host, sizeof (struct NCR5380_hostdata));
+ atari_scsi_host = instance;
+ instance->irq = IS_A_TT() ? IRQ_TT_MFP_SCSI : IRQ_MFP_FSCSI;
+
+ atari_scsi_reset_boot();
+ 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. */
+ add_isr(IRQ_TT_MFP_SCSI, scsi_tt_intr, IRQ_TYPE_PRIO,
+ NULL, "SCSI NCR5380");
+ tt_mfp.active_edge |= 0x80; /* SCSI int on L->H */
+#ifdef REAL_DMA
+ /* On the TT, we got a second interrupt for DMA ready and DMA buserror.
+ * Since on DMA ready we get a "normal" interrupt, too, the service
+ * routine for the second int just checks for buserrs.
+ */
+ add_isr(IRQ_TT_MFP_SCSIDMA, scsi_dma_buserr, IRQ_TYPE_SLOW,
+ NULL, "SCSI DMA");
+ tt_mfp.active_edge &= ~0x20; /* DMA int on H->L */
+
+ tt_scsi_dma.dma_ctrl = 0;
+ atari_dma_residual = 0;
+#endif /* REAL_DMA */
+
+ if (is_medusa) {
+ /* 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;
+ }
+
+ }
+ 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( "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()) {
+ remove_isr (IRQ_TT_MFP_SCSI, scsi_tt_intr);
+#ifdef REAL_DMA
+ remove_isr (IRQ_TT_MFP_SCSIDMA, scsi_dma_buserr);
+#endif
+ }
+ if (atari_dma_bufffer)
+ scsi_init_free (atari_dma_buffer, STRAM_BUFFER_SIZE);
+ return 1;
+}
+#endif
+
+void 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.
+ */
+
+ /* Grmbl... the standard parameter parsing can't handle negative numbers
+ * :-( So let's do it ourselves!
+ */
+
+ int i = ints[0]+1, fact;
+
+ while( str && (isdigit(*str) || *str == '-') && i <= 10) {
+ if (*str == '-')
+ fact = -1, ++str;
+ else
+ fact = 1;
+ ints[i++] = simple_strtoul( str, NULL, 0 ) * fact;
+ if ((str = strchr( str, ',' )) != NULL)
+ ++str;
+ }
+ ints[0] = i-1;
+
+ 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_reset( Scsi_Cmnd *cmd )
+{
+ int rv;
+ struct NCR5380_hostdata *hostdata =
+ (struct NCR5380_hostdata *)cmd->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_reset( cmd );
+
+ /* Re-enable ints */
+ if (IS_A_TT()) {
+ atari_turnon_irq( IRQ_TT_MFP_SCSI );
+ }
+ else {
+ atari_turnon_irq( IRQ_MFP_FSCSI );
+ }
+ falcon_release_lock_if_possible(hostdata);
+
+ return( rv );
+}
+
+
+static void 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 );
+
+ for( end = jiffies + AFTER_RESET_DELAY; jiffies < end; )
+ barrier();
+
+ printk( " done\n" );
+}
+
+
+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 = VTOP( data );
+
+#if (NDEBUG & NDEBUG_DMA)
+ printk ("scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, dir = %d\n",
+ instance->host_no, data, addr, count, dir);
+#endif
+
+ 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_maintainance( addr, count, dir );
+
+ if (count == 0)
+ printk("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;
+
+ 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( VTOP(cmd->SCp.ptr) )) ?
+ STRAM_BUFFER_SIZE : 255*512;
+ if (possible_len > limit)
+ possible_len = limit;
+
+#if (NDEBUG & NDEBUG_DMA)
+ if (possible_len != wanted_len)
+ printk( "Sorry, must cut DMA transfer size to %ld bytes instead of %ld\n",
+ possible_len, wanted_len );
+#endif
+
+ 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"
+
+#ifdef MODULE
+Scsi_Host_Template driver_template = ATARI_SCSI;
+
+#include "scsi_module.c"
+#endif
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen, slshen@lbl.gov
with Sam's (original) version of this