path: root/drivers/scsi/ultrastor.c

/*
 *	ultrastor.c	Copyright (C) 1992 David B. Gentzel
 *	Low-level SCSI driver for UltraStor 14F, 24F, and 34F
 *	by David B. Gentzel, Whitfield Software Services, Carnegie, PA
 *	    (gentzel@nova.enet.dec.com)
 *  scatter/gather added by Scott Taylor (n217cg@tamuts.tamu.edu)
 *  24F and multiple command support by John F. Carr (jfc@athena.mit.edu)
 *    John's work modified by Caleb Epstein (cae@jpmorgan.com) and 
 *    Eric Youngdale (ericy@cais.com).
 *	Thanks to UltraStor for providing the necessary documentation
 *
 *  This is an old driver, for the 14F and 34F you should be using the
 *  u14-34f driver instead.
 */

/*
 * TODO:
 *	1. Find out why scatter/gather is limited to 16 requests per command.
 *         This is fixed, at least on the 24F, as of version 1.12 - CAE.
 *	2. Look at command linking (mscp.command_link and
 *	   mscp.command_link_id).  (Does not work with many disks, 
 *				and no performance increase.  ERY).
 *	3. Allow multiple adapters.
 */

/*
 * NOTES:
 *    The UltraStor 14F, 24F, and 34F are a family of intelligent, high
 *    performance SCSI-2 host adapters.  They all support command queueing
 *    and scatter/gather I/O.  Some of them can also emulate the standard
 *    WD1003 interface for use with OS's which don't support SCSI.  Here
 *    is the scoop on the various models:
 *	14F - ISA first-party DMA HA with floppy support and WD1003 emulation.
 *	14N - ISA HA with floppy support.  I think that this is a non-DMA
 *	      HA.  Nothing further known.
 *	24F - EISA Bus Master HA with floppy support and WD1003 emulation.
 *	34F - VL-Bus Bus Master HA with floppy support (no WD1003 emulation).
 *
 *    The 14F, 24F, and 34F are supported by this driver.
 *
 *    Places flagged with a triple question-mark are things which are either
 *    unfinished, questionable, or wrong.
 */

/* Changes from version 1.11 alpha to 1.12
 *
 * Increased the size of the scatter-gather list to 33 entries for
 * the 24F adapter (it was 16).  I don't have the specs for the 14F
 * or the 34F, so they may support larger s-g lists as well.
 *
 * Caleb Epstein <cae@jpmorgan.com>
 */

/* Changes from version 1.9 to 1.11
 *
 * Patches to bring this driver up to speed with the default kernel
 * driver which supports only the 14F and 34F adapters.  This version
 * should compile cleanly into 0.99.13, 0.99.12 and probably 0.99.11.
 *
 * Fixes from Eric Youngdale to fix a few possible race conditions and
 * several problems with bit testing operations (insufficient
 * parentheses).
 *
 * Removed the ultrastor_abort() and ultrastor_reset() functions
 * (enclosed them in #if 0 / #endif).  These functions, at least on
 * the 24F, cause the SCSI bus to do odd things and generally lead to
 * kernel panics and machine hangs.  This is like the Adaptec code.
 *
 * Use check/snarf_region for 14f, 34f to avoid I/O space address conflicts.
 */

/* Changes from version 1.8 to version 1.9
 *
 *  0.99.11 patches (cae@jpmorgan.com) */

/* Changes from version 1.7 to version 1.8
 *
 * Better error reporting.
 */

/* Changes from version 1.6 to version 1.7
 *
 * Removed CSIR command code.
 *
 * Better race condition avoidance (xchgb function added).
 *
 * Set ICM and OGM status to zero at probe (24F)
 *
 * reset sends soft reset to UltraStor adapter
 *
 * reset adapter if adapter interrupts with an invalid MSCP address
 *
 * handle aborted command interrupt (24F)
 *
 */

/* Changes from version 1.5 to version 1.6:
 *
 * Read MSCP address from ICM _before_ clearing the interrupt flag.
 * This fixes a race condition.
 */

/* Changes from version 1.4 to version 1.5:
 *
 * Abort now calls done when multiple commands are enabled.
 *
 * Clear busy when aborted command finishes, not when abort is called.
 *
 * More debugging messages for aborts.
 */

/* Changes from version 1.3 to version 1.4:
 *
 * Enable automatic request of sense data on error (requires newer version
 * of scsi.c to be useful).
 *
 * Fix PORT_OVERRIDE for 14F.
 *
 * Fix abort and reset to work properly (config.aborted wasn't cleared
 * after it was tested, so after a command abort no further commands would
 * work).
 *
 * Boot time test to enable SCSI bus reset (defaults to not allowing reset).
 *
 * Fix test for OGM busy -- the busy bit is in different places on the 24F.
 *
 * Release ICM slot by clearing first byte on 24F.
 */

#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/interrupt.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/ioport.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/stat.h>
#include <linux/bitops.h>

#include <asm/io.h>
#include <asm/system.h>
#include <asm/dma.h>

#define ULTRASTOR_PRIVATE	/* Get the private stuff from ultrastor.h */
#include "scsi.h"
#include <scsi/scsi_host.h>
#include "ultrastor.h"

#define FALSE 0
#define TRUE 1

#ifndef ULTRASTOR_DEBUG
#define ULTRASTOR_DEBUG (UD_ABORT|UD_CSIR|UD_RESET)
#endif

#define VERSION "1.12"

#define PACKED		__attribute__((packed))
#define ALIGNED(x)	__attribute__((aligned(x)))


/* The 14F uses an array of 4-byte ints for its scatter/gather list.
   The data can be unaligned, but need not be.  It's easier to give
   the list normal alignment since it doesn't need to fit into a
   packed structure.  */

typedef struct {
  u32 address;
  u32 num_bytes;
} ultrastor_sg_list;


/* MailBox SCSI Command Packet.  Basic command structure for communicating
   with controller. */
struct mscp {
  unsigned char opcode: 3;		/* type of command */
  unsigned char xdir: 2;		/* data transfer direction */
  unsigned char dcn: 1;		/* disable disconnect */
  unsigned char ca: 1;		/* use cache (if available) */
  unsigned char sg: 1;		/* scatter/gather operation */
  unsigned char target_id: 3;		/* target SCSI id */
  unsigned char ch_no: 2;		/* SCSI channel (always 0 for 14f) */
  unsigned char lun: 3;		/* logical unit number */
  unsigned int transfer_data PACKED;	/* transfer data pointer */
  unsigned int transfer_data_length PACKED;	/* length in bytes */
  unsigned int command_link PACKED;	/* for linking command chains */
  unsigned char scsi_command_link_id;	/* identifies command in chain */
  unsigned char number_of_sg_list;	/* (if sg is set) 8 bytes per list */
  unsigned char length_of_sense_byte;
  unsigned char length_of_scsi_cdbs;	/* 6, 10, or 12 */
  unsigned char scsi_cdbs[12];	/* SCSI commands */
  uns