ibmmca.c

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/*
 Low Level Linux Driver for the IBM Microchannel SCSI Subsystem for
 Linux Kernel >= 2.4.0.
 Copyright (c) 1995 Strom Systems, Inc. under the terms of the GNU
 General Public License. Written by Martin Kolinek, December 1995.
 Further development by: Chris Beauregard, Klaus Kudielka, Michael Lang
 See the file README.ibmmca for a detailed description of this driver,
 the commandline arguments and the history of its development.
 See the WWW-page: http://www.uni-mainz.de/~langm000/linux.html for latest
 updates, info and ADF-files for adapters supported by this driver.
*/

#ifndef LINUX_VERSION_CODE
#include <linux/version.h>
#endif
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,0)
#error "This driver works only with kernel 2.4.0 or higher!"
#endif
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/ctype.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/blk.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/mca.h>
#include <asm/system.h>
#include <linux/spinlock.h>
#include <asm/io.h>
#include <linux/init.h>
#include "sd.h"
#include "scsi.h"
#include "hosts.h"
#include "ibmmca.h"
#include <linux/config.h>

/* current version of this driver-source: */
#define IBMMCA_SCSI_DRIVER_VERSION "4.0a"

#define IBMLOCK spin_lock_irqsave(&io_request_lock, flags);
#define IBMUNLOCK spin_unlock_irqrestore(&io_request_lock, flags);

/* driver configuration */
#define IM_MAX_HOSTS     8 /* maximum number of host adapters */
#define IM_RESET_DELAY	60 /* seconds allowed for a reset */

/* driver debugging - #undef all for normal operation */
/* if defined: count interrupts and ignore this special one: */
#undef	IM_DEBUG_TIMEOUT	50            
#define TIMEOUT_PUN	0
#define TIMEOUT_LUN	0
/* verbose interrupt: */
#undef IM_DEBUG_INT                   
/* verbose queuecommand: */
#undef IM_DEBUG_CMD    
/* verbose queucommand for specific SCSI-device type: */
#undef IM_DEBUG_CMD_SPEC_DEV
/* verbose device probing */
#undef IM_DEBUG_PROBE

/* device type that shall be displayed on syslog (only during debugging): */
#define IM_DEBUG_CMD_DEVICE	TYPE_TAPE

/* relative addresses of hardware registers on a subsystem */
#define IM_CMD_REG(hi)	(hosts[(hi)]->io_port)   /*Command Interface, (4 bytes long) */
#define IM_ATTN_REG(hi)	(hosts[(hi)]->io_port+4) /*Attention (1 byte) */
#define IM_CTR_REG(hi)	(hosts[(hi)]->io_port+5) /*Basic Control (1 byte) */
#define IM_INTR_REG(hi)	(hosts[(hi)]->io_port+6) /*Interrupt Status (1 byte, r/o) */
#define IM_STAT_REG(hi)	(hosts[(hi)]->io_port+7) /*Basic Status (1 byte, read only) */

/* basic I/O-port of first adapter */
#define IM_IO_PORT	0x3540
/* maximum number of hosts that can be found */
#define IM_N_IO_PORT	8

/*requests going into the upper nibble of the Attention register */
/*note: the lower nibble specifies the device(0-14), or subsystem(15) */
#define IM_IMM_CMD	0x10	/*immediate command */
#define IM_SCB		0x30	/*Subsystem Control Block command */
#define IM_LONG_SCB	0x40	/*long Subsystem Control Block command */
#define IM_EOI		0xe0	/*end-of-interrupt request */

/*values for bits 7,1,0 of Basic Control reg. (bits 6-2 reserved) */
#define IM_HW_RESET	0x80	/*hardware reset */
#define IM_ENABLE_DMA	0x02	/*enable subsystem's busmaster DMA */
#define IM_ENABLE_INTR	0x01	/*enable interrupts to the system */

/*to interpret the upper nibble of Interrupt Status register */
/*note: the lower nibble specifies the device(0-14), or subsystem(15) */
#define IM_SCB_CMD_COMPLETED			0x10
#define IM_SCB_CMD_COMPLETED_WITH_RETRIES	0x50
#define IM_LOOP_SCATTER_BUFFER_FULL		0x60
#define IM_ADAPTER_HW_FAILURE			0x70
#define IM_IMMEDIATE_CMD_COMPLETED		0xa0
#define IM_CMD_COMPLETED_WITH_FAILURE		0xc0
#define IM_CMD_ERROR				0xe0
#define IM_SOFTWARE_SEQUENCING_ERROR		0xf0

/*to interpret bits 3-0 of Basic Status register (bits 7-4 reserved) */
#define IM_CMD_REG_FULL		0x08
#define IM_CMD_REG_EMPTY	0x04
#define IM_INTR_REQUEST		0x02
#define IM_BUSY			0x01

/*immediate commands (word written into low 2 bytes of command reg) */
#define IM_RESET_IMM_CMD	0x0400
#define IM_FEATURE_CTR_IMM_CMD	0x040c
#define IM_DMA_PACING_IMM_CMD	0x040d
#define IM_ASSIGN_IMM_CMD	0x040e
#define IM_ABORT_IMM_CMD	0x040f
#define IM_FORMAT_PREP_IMM_CMD	0x0417

/*SCB (Subsystem Control Block) structure */
struct im_scb {
   unsigned short command; /*command word (read, etc.) */
   unsigned short enable; /*enable word, modifies cmd */
   union {
      unsigned long log_blk_adr; /*block address on SCSI device */
      unsigned char scsi_cmd_length; /*6,10,12, for other scsi cmd */
   } u1;
   unsigned long sys_buf_adr; /*physical system memory adr */
   unsigned long sys_buf_length; /*size of sys mem buffer */
   unsigned long tsb_adr; /*Termination Status Block adr */
   unsigned long scb_chain_adr;	/*optional SCB chain address */
   union {
      struct {
	 unsigned short count; /*block count, on SCSI device */
	 unsigned short length;	/*block length, on SCSI device */
      } blk;
      unsigned char scsi_command[12]; /*other scsi command */
   } u2;
};

/*structure scatter-gather element (for list of system memory areas) */
struct im_sge {
   void *address;
   unsigned long byte_length;
};

/*structure returned by a get_pos_info command: */
struct im_pos_info {
   unsigned short pos_id;         /* adapter id */
   unsigned char pos_3a;          /* pos 3 (if pos 6 = 0) */
   unsigned char pos_2;           /* pos 2 */
   unsigned char int_level;       /* interrupt level IRQ 11 or 14 */
   unsigned char pos_4a;          /* pos 4 (if pos 6 = 0) */
   unsigned short connector_size; /* MCA connector size: 16 or 32 Bit */
   unsigned char num_luns;        /* number of supported luns per device */
   unsigned char num_puns;        /* number of supported puns */
   unsigned char pacing_factor;   /* pacing factor */
   unsigned char num_ldns;        /* number of ldns available */
   unsigned char eoi_off;         /* time EOI and interrupt inactive */
   unsigned char max_busy;        /* time between reset and busy on */
   unsigned short cache_stat;     /* ldn cachestat. Bit=1 = not cached */
   unsigned short retry_stat;     /* retry status of ldns. Bit=1=disabled */
   unsigned char pos_4b;          /* pos 4 (if pos 6 = 1) */
   unsigned char pos_3b;          /* pos 3 (if pos 6 = 1) */
   unsigned char pos_6;           /* pos 6 */
   unsigned char pos_5;           /* pos 5 */ 
   unsigned short max_overlap;    /* maximum overlapping requests */
   unsigned short num_bus;        /* number of SCSI-busses */
};

/*values for SCB command word */
#define IM_NO_SYNCHRONOUS      0x0040	/*flag for any command */
#define IM_NO_DISCONNECT       0x0080	/*flag for any command */
#define IM_READ_DATA_CMD       0x1c01
#define IM_WRITE_DATA_CMD      0x1c02
#define IM_READ_VERIFY_CMD     0x1c03
#define IM_WRITE_VERIFY_CMD    0x1c04
#define IM_REQUEST_SENSE_CMD   0x1c08
#define IM_READ_CAPACITY_CMD   0x1c09
#define IM_DEVICE_INQUIRY_CMD  0x1c0b
#define IM_READ_LOGICAL_CMD    0x1c2a
#define IM_OTHER_SCSI_CMD_CMD  0x241f

/* unused, but supported, SCB commands */
#define IM_GET_COMMAND_COMPLETE_STATUS_CMD   0x1c07 /* command status */
#define IM_GET_POS_INFO_CMD                  0x1c0a /* returns neat stuff */
#define IM_READ_PREFETCH_CMD                 0x1c31 /* caching controller only */
#define IM_FOMAT_UNIT_CMD                    0x1c16 /* format unit */
#define IM_REASSIGN_BLOCK_CMD                0x1c18 /* in case of error */

/*values to set bits in the enable word of SCB */
#define IM_READ_CONTROL              0x8000
#define IM_REPORT_TSB_ONLY_ON_ERROR  0x4000
#define IM_RETRY_ENABLE              0x2000
#define IM_POINTER_TO_LIST           0x1000
#define IM_SUPRESS_EXCEPTION_SHORT   0x0400
#define IM_BYPASS_BUFFER             0x0200
#define IM_CHAIN_ON_NO_ERROR         0x0001

/*TSB (Termination Status Block) structure */
struct im_tsb {
   unsigned short end_status;
   unsigned short reserved1;
   unsigned long residual_byte_count;
   unsigned long sg_list_element_adr;
   unsigned short status_length;
   unsigned char dev_status;
   unsigned char cmd_status;
   unsigned char dev_error;
   unsigned char cmd_error;
   unsigned short reserved2;
   unsigned short reserved3;
   unsigned short low_of_last_scb_adr;
   unsigned short high_of_last_scb_adr;
};

/*subsystem uses interrupt request level 14 */
#define IM_IRQ     14
/*SCSI-2 F/W may evade to interrupt 11 */
#define IM_IRQ_FW  11

/* Model 95 has an additional alphanumeric display, which can be used
   to display SCSI-activities. 8595 models do not have any disk led, which
   makes this feature quite useful.
   The regular PS/2 disk led is turned on/off by bits 6,7 of system
   control port. */

/* LED display-port (actually, last LED on display) */
#define MOD95_LED_PORT	   0x108
/* system-control-register of PS/2s with diskindicator */
#define PS2_SYS_CTR        0x92
/* activity displaying methods */
#define LED_DISP           1
#define LED_ADISP          2
#define LED_ACTIVITY       4
/* failed intr */
#define CMD_FAIL           255

/* The SCSI-ID(!) of the accessed SCSI-device is shown on PS/2-95 machines' LED
   displays. ldn is no longer displayed here, because the ldn mapping is now 
   done dynamically and the ldn <-> pun,lun maps can be looked-up at boottime 
   or during uptime in /proc/scsi/ibmmca/<host_no> in case of trouble, 
   interest, debugging or just for having fun. The left number gives the
   host-adapter number and the right shows the accessed SCSI-ID. */

/* display_mode is set by the ibmmcascsi= command line arg */
static int display_mode = 0;
/* set default adapter timeout */
static unsigned int adapter_timeout = 45;
/* for probing on feature-command: */
static unsigned int global_command_error_excuse = 0;
/* global setting by command line for adapter_speed */
static int global_adapter_speed = 0; /* full speed by default */

/* Panel / LED on, do it right for F/W addressin, too. adisplay will
 * just ignore ids>7, as the panel has only 7 digits available */
#define PS2_DISK_LED_ON(ad,id) { if (display_mode & LED_DISP) { if (id>9) \
    outw((ad+48)|((id+55)<<8), MOD95_LED_PORT ); else \
    outw((ad+48)|((id+48)<<8), MOD95_LED_PORT ); } else \
    if (display_mode & LED_ADISP) { if (id<7) outb((char)(id+48),MOD95_LED_PORT+1+id); \
    outb((char)(ad+48), MOD95_LED_PORT); } \
    if ((display_mode & LED_ACTIVITY)||(!display_mode)) \
    outb(inb(PS2_SYS_CTR) | 0xc0, PS2_SYS_CTR); }

/* Panel / LED off */
/* bug fixed, Dec 15, 1997, where | was replaced by & here */
#define PS2_DISK_LED_OFF() { if (display_mode & LED_DISP) \
    outw(0x2020, MOD95_LED_PORT ); else if (display_mode & LED_ADISP) { \
    outl(0x20202020,MOD95_LED_PORT); outl(0x20202020,MOD95_LED_PORT+4); } \
    if ((display_mode & LED_ACTIVITY)||(!display_mode)) \
    outb(inb(PS2_SYS_CTR) & 0x3f, PS2_SYS_CTR); }

/*list of supported subsystems */
struct subsys_list_struct {
   unsigned short mca_id;
   char *description;
};

/* types of different supported hardware that goes to hostdata special */
#define IBM_SCSI2_FW     0
#define IBM_7568_WCACHE  1
#define IBM_EXP_UNIT     2
#define IBM_SCSI_WCACHE  3
#define IBM_SCSI         4

/* other special flags for hostdata structure */
#define FORCED_DETECTION         100
#define INTEGRATED_SCSI          101

/* List of possible IBM-SCSI-adapters */
struct subsys_list_struct subsys_list[] = {
 {0x8efc,"IBM SCSI-2 F/W Adapter"}, /* special = 0 */
 {0x8efd,"IBM 7568 Industrial Computer SCSI Adapter w/Cache"}, /* special = 1 */
 {0x8ef8,"IBM Expansion Unit SCSI Controller"},/* special = 2 */
 {0x8eff,"IBM SCSI Adapter w/Cache"}, /* special = 3 */
 {0x8efe,"IBM SCSI Adapter"}, /* special = 4 */
};

/* Max number of logical devices (can be up from 0 to 14).  15 is the address
of the adapter itself. */
#define MAX_LOG_DEV  15

/*local data for a logical device */
struct logical_device {
   struct im_scb scb; /* SCSI-subsystem-control-block structure */
   struct im_tsb tsb; /* SCSI command complete status block structure */
   struct im_sge sge[16]; /* scatter gather list structure */
   unsigned char buf[256]; /* SCSI command return data buffer */
   Scsi_Cmnd *cmd;  /* SCSI-command that is currently in progress */
   int device_type; /* type of the SCSI-device. See include/scsi/scsi.h
		       for interpretation of the possible values */
   int block_length; /* blocksize of a particular logical SCSI-device */
   int cache_flag; /* 1 if this is uncached, 0 if cache is present for ldn */
   int retry_flag; /* 1 if adapter retry is disabled, 0 if enabled */
};

/* statistics of the driver during operations (for proc_info) */
struct Driver_Statistics {
   /* SCSI statistics on the adapter */
   int ldn_access[MAX_LOG_DEV+1];         /* total accesses on a ldn */
   int ldn_read_access[MAX_LOG_DEV+1];    /* total read-access on a ldn */
   int ldn_write_access[MAX_LOG_DEV+1];   /* total write-access on a ldn */
   int ldn_inquiry_access[MAX_LOG_DEV+1]; /* total inquiries on a ldn */
   int ldn_modeselect_access[MAX_LOG_DEV+1]; /* total mode selects on ldn */
   int scbs;                              /* short SCBs queued */
   int long_scbs;                         /* long SCBs queued */
   int total_accesses;                    /* total accesses on all ldns */
   int total_interrupts;                  /* total interrupts (should be
					     same as total_accesses) */
   int total_errors;                      /* command completed with error */
   /* dynamical assignment statistics */
   int total_scsi_devices;                /* number of physical pun,lun */
   int dyn_flag;                          /* flag showing dynamical mode */
   int dynamical_assignments;             /* number of remappings of ldns */
   int ldn_assignments[MAX_LOG_DEV+1];    /* number of remappings of each
					     ldn */
};

/* data structure for each host adapter */
struct ibmmca_hostdata {
   /* array of logical devices: */