wd7000.c

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/* $Id: $
 *  linux/drivers/scsi/wd7000.c
 *
 *  Copyright (C) 1992  Thomas Wuensche
 *	closely related to the aha1542 driver from Tommy Thorn
 *	( as close as different hardware allows on a lowlevel-driver :-) )
 *
 *  Revised (and renamed) by John Boyd <[e-mail]> to
 *  accommodate Eric Youngdale's modifications to scsi.c.  Nov 1992.
 *
 *  Additional changes to support scatter/gather.  Dec. 1992.  tw/jb
 *
 *  No longer tries to reset SCSI bus at boot (it wasn't working anyway).
 *  Rewritten to support multiple host adapters.
 *  Miscellaneous cleanup.
 *  So far, still doesn't do reset or abort correctly, since I have no idea
 *  how to do them with this board (8^(.                      Jan 1994 jb
 *
 * This driver now supports both of the two standard configurations (per
 * the 3.36 Owner's Manual, my latest reference) by the same method as
 * before; namely, by looking for a BIOS signature.  Thus, the location of
 * the BIOS signature determines the board configuration.  Until I have
 * time to do something more flexible, users should stick to one of the
 * following:
 *
 * Standard configuration for single-adapter systems:
 *    - BIOS at CE00h
 *    - I/O base address 350h
 *    - IRQ level 15
 *    - DMA channel 6
 * Standard configuration for a second adapter in a system:
 *    - BIOS at C800h
 *    - I/O base address 330h
 *    - IRQ level 11
 *    - DMA channel 5
 *
 * Anyone who can recompile the kernel is welcome to add others as need
 * arises, but unpredictable results may occur if there are conflicts.
 * In any event, if there are multiple adapters in a system, they MUST
 * use different I/O bases, IRQ levels, and DMA channels, since they will be
 * indistinguishable (and in direct conflict) otherwise.
 *
 *   As a point of information, the NO_OP command toggles the CMD_RDY bit
 * of the status port, and this fact could be used as a test for the I/O
 * base address (or more generally, board detection).  There is an interrupt
 * status port, so IRQ probing could also be done.  I suppose the full
 * DMA diagnostic could be used to detect the DMA channel being used.  I
 * haven't done any of this, though, because I think there's too much of
 * a chance that such explorations could be destructive, if some other
 * board's resources are used inadvertently.  So, call me a wimp, but I
 * don't want to try it.  The only kind of exploration I trust is memory
 * exploration, since it's more certain that reading memory won't be
 * destructive.
 *
 * More to my liking would be a LILO boot command line specification, such
 * as is used by the aha152x driver (and possibly others).  I'll look into
 * it, as I have time...
 *
 *   I get mail occasionally from people who either are using or are
 * considering using a WD7000 with Linux.  There is a variety of
 * nomenclature describing WD7000's.  To the best of my knowledge, the
 * following is a brief summary (from an old WD doc - I don't work for
 * them or anything like that):
 *
 * WD7000-FASST2: This is a WD7000 board with the real-mode SST ROM BIOS
 *        installed.  Last I heard, the BIOS was actually done by Columbia
 *        Data Products.  The BIOS is only used by this driver (and thus
 *        by Linux) to identify the board; none of it can be executed under
 *        Linux.
 *
 * WD7000-ASC: This is the original adapter board, with or without BIOS.
 *        The board uses a WD33C93 or WD33C93A SBIC, which in turn is
 *        controlled by an onboard Z80 processor.  The board interface
 *        visible to the host CPU is defined effectively by the Z80's
 *        firmware, and it is this firmware's revision level that is
 *        determined and reported by this driver.  (The version of the
 *        on-board BIOS is of no interest whatsoever.)  The host CPU has
 *        no access to the SBIC; hence the fact that it is a WD33C93 is
 *        also of no interest to this driver.
 *
 * WD7000-AX:
 * WD7000-MX:
 * WD7000-EX: These are newer versions of the WD7000-ASC.  The -ASC is
 *        largely built from discrete components; these boards use more
 *        integration.  The -AX is an ISA bus board (like the -ASC),
 *        the -MX is an MCA (i.e., PS/2) bus board), and the -EX is an
 *        EISA bus board.
 *
 *  At the time of my documentation, the -?X boards were "future" products,
 *  and were not yet available.  However, I vaguely recall that Thomas
 *  Wuensche had an -AX, so I believe at least it is supported by this
 *  driver.  I have no personal knowledge of either -MX or -EX boards.
 *
 *  P.S. Just recently, I've discovered (directly from WD and Future
 *  Domain) that all but the WD7000-EX have been out of production for
 *  two years now.  FD has production rights to the 7000-EX, and are
 *  producing it under a new name, and with a new BIOS.  If anyone has
 *  one of the FD boards, it would be nice to come up with a signature
 *  for it.
 *                                                           J.B. Jan 1994.
 *
 *
 *  Revisions by Miroslav Zagorac <[e-mail]>
 *
 *  08/24/1996.
 *
 *  Enhancement for wd7000_detect function has been made, so you don't have
 *  to enter BIOS ROM address in initialisation data (see struct Config).
 *  We cannot detect IRQ, DMA and I/O base address for now, so we have to
 *  enter them as arguments while wd_7000 is detected. If someone has IRQ,
 *  DMA or I/O base address set to some other value, he can enter them in
 *  configuration without any problem. Also I wrote a function wd7000_setup,
 *  so now you can enter WD-7000 definition as kernel arguments,
 *  as in lilo.conf:
 *
 *     append="wd7000=IRQ,DMA,IO"
 *
 *  PS: If card BIOS ROM is disabled, function wd7000_detect now will recognize
 *      adapter, unlike the old one. Anyway, BIOS ROM from WD7000 adapter is
 *      useless for Linux. B^)
 *
 *
 *  09/06/1996.
 *
 *  Autodetecting of I/O base address from wd7000_detect function is removed,
 *  some little bugs removed, etc...
 *
 *  Thanks to Roger Scott for driver debugging.
 *
 *  06/07/1997
 *
 *  Added support for /proc file system (/proc/scsi/wd7000/[0...] files).
 *  Now, driver can handle hard disks with capacity >1GB.
 *
 *  01/15/1998
 *
 *  Added support for BUS_ON and BUS_OFF parameters in config line.
 *  Miscellaneous cleanup.
 *
 *  03/01/1998
 *
 *  WD7000 driver now work on kernels >= 2.1.x
 */

#ifdef MODULE
#include <linux/module.h>
#endif

#include <stdarg.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/malloc.h>
#include <linux/spinlock.h>
#include <asm/system.h>
#include <asm/dma.h>
#include <asm/io.h>
#include <linux/ioport.h>
#include <linux/proc_fs.h>
#include <linux/blk.h>
#include <linux/version.h>
#include <linux/init.h>
#include "scsi.h"
#include "hosts.h"
#include "sd.h"
#include <scsi/scsicam.h>

#define ANY2SCSI_INLINE		/* undef this to use old macros */
#undef  WD7000_DEBUG		/* general debug                */

#include "wd7000.h"
#include <linux/stat.h>

/*
 *  Mailbox structure sizes.
 *  I prefer to keep the number of ICMBs much larger than the number of
 *  OGMBs.  OGMBs are used very quickly by the driver to start one or
 *  more commands, while ICMBs are used by the host adapter per command.
 */
#define OGMB_CNT	16
#define ICMB_CNT	32

/*
 *  Scb's are shared by all active adapters.  So, if they all become busy,
 *  callers may be made to wait in alloc_scbs for them to free.  That can
 *  be avoided by setting MAX_SCBS to NUM_CONFIG * WD7000_Q.  If you'd
 *  rather conserve memory, use a smaller number (> 0, of course) - things
 *  will should still work OK.
 */
#define MAX_SCBS        32

/*
 *  WD7000-specific mailbox structure
 *
 */
typedef volatile struct mailbox {
    unchar status;
    unchar scbptr[3];		/* SCSI-style - MSB first (big endian) */
} Mailbox;

/*
 *  This structure should contain all per-adapter global data.  I.e., any
 *  new global per-adapter data should put in here.
 */
typedef struct adapter {
    struct Scsi_Host *sh;	/* Pointer to Scsi_Host structure    */
    int iobase;			/* This adapter's I/O base address   */
    int irq;			/* This adapter's IRQ level          */
    int dma;			/* This adapter's DMA channel        */
    int int_counter;		/* This adapter's interrupt counter  */
    int bus_on;			/* This adapter's BUS_ON time        */
    int bus_off;		/* This adapter's BUS_OFF time       */
    struct {			/* This adapter's mailboxes          */
	Mailbox ogmb[OGMB_CNT];	/* Outgoing mailboxes                */
	Mailbox icmb[ICMB_CNT];	/* Incoming mailboxes                */
    } mb;
    int next_ogmb;		/* to reduce contention at mailboxes */
    unchar control;		/* shadows CONTROL port value        */
    unchar rev1, rev2;		/* filled in by wd7000_revision      */
} Adapter;

/*
 * (linear) base address for ROM BIOS
 */
static const long wd7000_biosaddr[] =
{
    0xc0000, 0xc2000, 0xc4000, 0xc6000, 0xc8000, 0xca000, 0xcc000, 0xce000,
    0xd0000, 0xd2000, 0xd4000, 0xd6000, 0xd8000, 0xda000, 0xdc000, 0xde000
};
#define NUM_ADDRS (sizeof(wd7000_biosaddr)/sizeof(long))

static const unsigned short wd7000_iobase[] =
{
    0x0300, 0x0308, 0x0310, 0x0318, 0x0320, 0x0328, 0x0330, 0x0338,
    0x0340, 0x0348, 0x0350, 0x0358, 0x0360, 0x0368, 0x0370, 0x0378,
    0x0380, 0x0388, 0x0390, 0x0398, 0x03a0, 0x03a8, 0x03b0, 0x03b8,
    0x03c0, 0x03c8, 0x03d0, 0x03d8, 0x03e0, 0x03e8, 0x03f0, 0x03f8
};
#define NUM_IOPORTS (sizeof(wd7000_iobase)/sizeof(unsigned short))

static const short wd7000_irq[] = { 3, 4, 5, 7, 9, 10, 11, 12, 14, 15 };
#define NUM_IRQS (sizeof(wd7000_irq)/sizeof(short))

static const short wd7000_dma[] = { 5, 6, 7 };
#define NUM_DMAS (sizeof(wd7000_dma)/sizeof(short))

/*
 * possible irq range
 */
#define IRQ_MIN   3
#define IRQ_MAX   15
#define IRQS      (IRQ_MAX - IRQ_MIN + 1)

/*
 * The following is set up by wd7000_detect, and used thereafter by
 * wd7000_intr_handle to map the irq level to the corresponding Adapter.
 * Note that if SA_INTERRUPT is not used, wd7000_intr_handle must be
 * changed to pick up the IRQ level correctly.
 */
static struct Scsi_Host *wd7000_host[IRQS];

#define BUS_ON    64	/* x 125ns = 8000ns (BIOS default) */
#define BUS_OFF   15	/* x 125ns = 1875ns (BIOS default) */

/*
 *  Standard Adapter Configurations - used by wd7000_detect
 */
typedef struct {
    short irq;		/* IRQ level                                  */
    short dma;		/* DMA channel                                */
    unsigned iobase;	/* I/O base address                           */
    short bus_on;	/* Time that WD7000 spends on the AT-bus when */
			/* transferring data. BIOS default is 8000ns. */
    short bus_off;	/* Time that WD7000 spends OFF THE BUS after  */
			/* while it is transferring data.             */
			/* BIOS default is 1875ns                     */
} Config;

/*
 * Add here your configuration...
 */
static Config configs[] =
{
    { 15,  6, 0x350, BUS_ON, BUS_OFF },	/* defaults for single adapter */
    { 11,  5, 0x320, BUS_ON, BUS_OFF },	/* defaults for second adapter */
    {  7,  6, 0x350, BUS_ON, BUS_OFF },	/* My configuration (Zaga)     */
    { -1, -1, 0x0,   BUS_ON, BUS_OFF }	/* Empty slot                  */
};
#define NUM_CONFIGS (sizeof(configs)/sizeof(Config))

/*
 *  The following list defines strings to look for in the BIOS that identify
 *  it as the WD7000-FASST2 SST BIOS.  I suspect that something should be
 *  added for the Future Domain version.
 */
typedef struct signature {
    const char *sig;		/* String to look for            */
    unsigned long ofs;		/* offset from BIOS base address */
    unsigned len;		/* length of string              */
} Signature;

static const Signature signatures[] =
{
    {"SSTBIOS", 0x0000d, 7}	/* "SSTBIOS" @ offset 0x0000d */
};
#define NUM_SIGNATURES (sizeof(signatures)/sizeof(Signature))


/*
 *  I/O Port Offsets and Bit Definitions
 *  4 addresses are used.  Those not defined here are reserved.
 */
#define ASC_STAT        0	/* Status,  Read          */
#define ASC_COMMAND     0	/* Command, Write         */
#define ASC_INTR_STAT   1	/* Interrupt Status, Read */
#define ASC_INTR_ACK    1	/* Acknowledge, Write     */
#define ASC_CONTROL     2	/* Control, Write         */

/*
 * ASC Status Port
 */
#define INT_IM		0x80	/* Interrupt Image Flag           */
#define CMD_RDY		0x40	/* Command Port Ready             */
#define CMD_REJ		0x20	/* Command Port Byte Rejected     */
#define ASC_INIT        0x10	/* ASC Initialized Flag           */
#define ASC_STATMASK    0xf0	/* The lower 4 Bytes are reserved */

/*
 * COMMAND opcodes
 *
 *  Unfortunately, I have no idea how to properly use some of these commands,
 *  as the OEM manual does not make it clear.  I have not been able to use
 *  enable/disable unsolicited interrupts or the reset commands with any
 *  discernible effect whatsoever.  I think they may be related to certain
 *  ICB commands, but again, the OEM manual doesn't make that clear.
 */
#define NO_OP             0	/* NO-OP toggles CMD_RDY bit in ASC_STAT  */
#define INITIALIZATION    1	/* initialization (10 bytes)              */
#define DISABLE_UNS_INTR  2	/* disable unsolicited interrupts         */
#define ENABLE_UNS_INTR   3	/* enable unsolicited interrupts          */
#define INTR_ON_FREE_OGMB 4	/* interrupt on free OGMB                 */
#define SOFT_RESET        5	/* SCSI bus soft reset                    */
#define HARD_RESET_ACK    6	/* SCSI bus hard reset acknowledge        */
#define START_OGMB        0x80	/* start command in OGMB (n)              */
#define SCAN_OGMBS        0xc0	/* start multiple commands, signature (n) */
				/*    where (n) = lower 6 bits            */
/*
 * For INITIALIZATION:
 */
typedef struct initCmd {
    unchar op;			/* command opcode (= 1)                    */
    unchar ID;			/* Adapter's SCSI ID                       */
    unchar bus_on;		/* Bus on time, x 125ns (see below)        */
    unchar bus_off;		/* Bus off time, ""         ""             */
    unchar rsvd;		/* Reserved                                */
    unchar mailboxes[3];	/* Address of Mailboxes, MSB first         */
    unchar ogmbs;		/* Number of outgoing MBs, max 64, 0,1 = 1 */
    unchar icmbs;		/* Number of incoming MBs,   ""       ""   */
} InitCmd;

/*
 * Interrupt Status Port - also returns diagnostic codes at ASC reset
 *
 * if msb is zero, the lower bits are diagnostic status
 * Diagnostics:
 * 01   No diagnostic error occurred
 * 02   RAM failure
 * 03   FIFO R/W failed
 * 04   SBIC register read/write failed
 * 05   Initialization D-FF failed
 * 06   Host IRQ D-FF failed
 * 07   ROM checksum error
 * Interrupt status (bitwise):
 * 10NNNNNN   outgoing mailbox NNNNNN is free
 * 11NNNNNN   incoming mailbox NNNNNN needs service
 */
#define MB_INTR    0xC0		/* Mailbox Service possible/required */
#define IMB_INTR   0x40		/* 1 Incoming / 0 Outgoing           */
#define MB_MASK    0x3f		/* mask for mailbox number           */

/*
 * CONTROL port bits
 */
#define INT_EN     0x08		/* Interrupt Enable */
#define DMA_EN     0x04		/* DMA Enable       */
#define SCSI_RES   0x02		/* SCSI Reset       */
#define ASC_RES    0x01		/* ASC Reset        */

/*
 * Driver data structures:
 *   - mb and scbs are required for interfacing with the host adapter.
 *     An SCB has extra fields not visible to the adapter; mb's
 *     _cannot_ do this, since the adapter assumes they are contiguous in
 *     memory, 4 bytes each, with ICMBs following OGMBs, and uses this fact
 *     to access them.
 *   - An icb is for host-only (non-SCSI) commands.  ICBs are 16 bytes each;
 *     the additional bytes are used only by the driver.
 *   - For now, a pool of SCBs are kept in global storage by this driver,
 *     and are allocated and freed as needed.
 *
 *  The 7000-FASST2 marks OGMBs empty as soon as it has _started_ a command,
 *  not when it has finished.  Since the SCB must be around for completion,
 *  problems arise when SCBs correspond to OGMBs, which may be reallocated
 *  earlier (or delayed unnecessarily until a command completes).
 *  Mailboxes are used as transient data structures, simply for
 *  carrying SCB addresses to/from the 7000-FASST2.
 *
 *  Note also since SCBs are not "permanently" associated with mailboxes,
 *  there is no need to keep a global list of Scsi_Cmnd pointers indexed
 *  by OGMB.   Again, SCBs reference their Scsi_Cmnds directly, so mailbox
 *  indices need not be involved.
 */

/*
 *  WD7000-specific scatter/gather element structure
 */
typedef struct sgb {
    unchar len[3];
    unchar ptr[3];		/* Also SCSI-style - MSB first */
} Sgb;

typedef struct scb {		/* Command Control Block 5.4.1               */
    unchar op;			/* Command Control Block Operation Code      */
    unchar idlun;		/* op=0,2:Target Id, op=1:Initiator Id       */
				/* Outbound data transfer, length is checked */
				/* Inbound data transfer, length is checked  */
				/* Logical Unit Number                       */
    unchar cdb[12];		/* SCSI Command Block                        */
    volatile unchar status;	/* SCSI Return Status                        */
    volatile unchar vue;	/* Vendor Unique Error Code                  */
    unchar maxlen[3];		/* Maximum Data Transfer Length              */
    unchar dataptr[3];		/* SCSI Data Block Pointer                   */
    unchar linkptr[3];		/* Next Command Link Pointer                 */
    unchar direc;		/* Transfer Direction                        */
    unchar reserved2[6];	/* SCSI Command Descriptor Block             */
				/* end of hardware SCB                       */
    Scsi_Cmnd *SCpnt;		/* Scsi_Cmnd using this SCB                  */
    Sgb sgb[WD7000_SG];		/* Scatter/gather list for this SCB          */
    Adapter *host;		/* host adapter                              */
    struct scb *next;		/* for lists of scbs                         */
} Scb;

/*
 *  This driver is written to allow host-only commands to be executed.
 *  These use a 16-byte block called an ICB.  The format is extended by the
 *  driver to 18 bytes, to support the status returned in the ICMB and