scsi_debug.c

基于组件方式开发操作系统的OSKIT源代码

/* $Id: scsi_debug.c,v 1.1 1992/07/24 06:27:38 root Exp root $
 *  linux/kernel/scsi_debug.c
 *
 *  Copyright (C) 1992  Eric Youngdale
 *  Simulate a host adapter with 2 disks attached.  Do a lot of checking
 *  to make sure that we are not getting blocks mixed up, and panic if
 *  anything out of the ordinary is seen.
 */

#include <linux/module.h>

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/genhd.h>
#include <linux/fs.h>
#include <linux/proc_fs.h>

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

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

#include <linux/blk.h>
#include "scsi.h"
#include "hosts.h"

#include "sd.h"

#include<linux/stat.h>

struct proc_dir_entry proc_scsi_scsi_debug = {
    PROC_SCSI_SCSI_DEBUG, 10, "scsi_debug",
    S_IFDIR | S_IRUGO | S_IXUGO, 2
};


/* A few options that we want selected */

#define NR_HOSTS_PRESENT 20
#define NR_FAKE_DISKS   6
#define N_HEAD          32
#define N_SECTOR        64
#define DISK_READONLY(TGT)      (1)
#define DISK_REMOVEABLE(TGT)    (1)

/* Do not attempt to use a timer to simulate a real disk with latency */
/* Only use this in the actual kernel, not in the simulator. */
/* #define IMMEDIATE */

/* Skip some consistency checking.  Good for benchmarking */
#define SPEEDY
/* Read return zeros. Undefine for benchmarking */
#define CLEAR

/* Number of real scsi disks that will be detected ahead of time */
static int NR_REAL=-1;

#define NR_BLK_DEV  12
#ifndef MAJOR_NR
#define MAJOR_NR 8
#endif
#define START_PARTITION 4

/* Number of jiffies to wait before completing a command */
#define DISK_SPEED     10
#define CAPACITY (0x80000)

static int starts[] = {N_HEAD, N_HEAD * N_SECTOR, 50000, CAPACITY, 0};
static int npart = 0;

#include "scsi_debug.h"
#ifdef DEBUG
#define DEB(x) x
#else
#define DEB(x)
#endif

#ifdef SPEEDY
#define VERIFY1_DEBUG(RW) 
#define VERIFY_DEBUG(RW) 
#else

#define VERIFY1_DEBUG(RW)                           \
    if (bufflen != 1024) {printk("%d", bufflen); panic("(1)Bad bufflen");};         \
    start = 0;                          \
    if ((MINOR(SCpnt->request.rq_dev) & 0xf) != 0) start = starts[(MINOR(SCpnt->request.rq_dev) & 0xf) - 1];        \
    if (bh){                            \
	if (bh->b_size != 1024) panic ("Wrong bh size");    \
	if ((bh->b_blocknr << 1) + start != block)          \
	{   printk("Wrong bh block# %d %d ",bh->b_blocknr, block);  \
	    panic ("Wrong bh block#"); \
	};  \
	if (bh->b_dev != SCpnt->request.rq_dev)  \
	    panic ("Bad bh target"); \
    };

#define VERIFY_DEBUG(RW)                            \
    if (bufflen != 1024 && (!SCpnt->use_sg)) {printk("%x %d\n ",bufflen, SCpnt->use_sg); panic("Bad bufflen");};    \
    start = 0;                          \
    if ((MINOR(SCpnt->request.rq_dev) & 0xf) > npart) panic ("Bad partition");    \
    if ((MINOR(SCpnt->request.rq_dev) & 0xf) != 0) start = starts[(MINOR(SCpnt->request.rq_dev) & 0xf) - 1];        \
    if (SCpnt->request.cmd != RW) panic ("Wrong  operation");       \
    if (SCpnt->request.sector + start != block) panic("Wrong block.");  \
    if (SCpnt->request.current_nr_sectors != 2 && (!SCpnt->use_sg)) panic ("Wrong # blocks");   \
    if (SCpnt->request.bh){                         \
	if (SCpnt->request.bh->b_size != 1024) panic ("Wrong bh size"); \
	if ((SCpnt->request.bh->b_blocknr << 1) + start != block)           \
	{   printk("Wrong bh block# %d %d ",SCpnt->request.bh->b_blocknr, block);  \
	    panic ("Wrong bh block#"); \
	};  \
	if (SCpnt->request.bh->b_dev != SCpnt->request.rq_dev) \
	    panic ("Bad bh target");\
    };
#endif

typedef void (*done_fct_t)(Scsi_Cmnd *);

static volatile done_fct_t do_done[SCSI_DEBUG_MAILBOXES] = {NULL, };

static void scsi_debug_intr_handle(unsigned long);

static struct timer_list timeout[SCSI_DEBUG_MAILBOXES];

Scsi_Cmnd * SCint[SCSI_DEBUG_MAILBOXES] = {NULL,};
static char SCrst[SCSI_DEBUG_MAILBOXES] = {0,};

/*
 * Semaphore used to simulate bus lockups.
 */
static int scsi_debug_lockup = 0;

static char sense_buffer[128] = {0,};

static void scsi_dump(Scsi_Cmnd * SCpnt, int flag){
    int i;
#if 0
    unsigned char * pnt;
#endif
    unsigned int * lpnt;
    struct scatterlist * sgpnt = NULL;
    printk("use_sg: %d",SCpnt->use_sg);
    if (SCpnt->use_sg){
	sgpnt = (struct scatterlist *) SCpnt->buffer;
	for(i=0; i<SCpnt->use_sg; i++) {
	    lpnt = (int *) sgpnt[i].alt_address;
	    printk(":%p %p %d\n",sgpnt[i].alt_address, sgpnt[i].address, sgpnt[i].length);
	    if (lpnt) printk(" (Alt %x) ",lpnt[15]);
	};
    } else {
	printk("nosg: %p %p %d\n",SCpnt->request.buffer, SCpnt->buffer,
	       SCpnt->bufflen);
	lpnt = (int *) SCpnt->request.buffer;
	if (lpnt) printk(" (Alt %x) ",lpnt[15]);
    };
    lpnt = (unsigned int *) SCpnt;
    for (i=0;i<sizeof(Scsi_Cmnd)/4+1; i++) {
	if ((i & 7) == 0) printk("\n");
	printk("%x ",*lpnt++);
    };
    printk("\n");
    if (flag == 0) return;
    lpnt = (unsigned int *) sgpnt[0].alt_address;
    for (i=0;i<sizeof(Scsi_Cmnd)/4+1; i++) {
	if ((i & 7) == 0) printk("\n");
	printk("%x ",*lpnt++);
    };
#if 0
    printk("\n");
    lpnt = (unsigned int *) sgpnt[0].address;
    for (i=0;i<sizeof(Scsi_Cmnd)/4+1; i++) {
	if ((i & 7) == 0) printk("\n");
	printk("%x ",*lpnt++);
    };
    printk("\n");
#endif
    printk("DMA free %d sectors.\n", scsi_dma_free_sectors);
}

int scsi_debug_queuecommand(Scsi_Cmnd * SCpnt, void (*done)(Scsi_Cmnd *))
{
    unchar *cmd = (unchar *) SCpnt->cmnd;
    struct partition * p;
    int block;
    struct buffer_head * bh = NULL;
    unsigned char * buff;
    int nbytes, sgcount;
    int scsi_debug_errsts;
    struct scatterlist * sgpnt;
    int target = SCpnt->target;
    int bufflen = SCpnt->request_bufflen;
    unsigned long flags;
    int i;
    sgcount = 0;
    sgpnt = NULL;
    
    /*
     * If we are being notified of the mid-level reposessing a command due to timeout,
     * just return.
     */
    if( done == NULL )
    {
        return 0;
    }

    DEB(if (target >= NR_FAKE_DISKS) 
        { 
            SCpnt->result = DID_TIME_OUT << 16;done(SCpnt);return 0;
        });
    
    buff = (unsigned char *) SCpnt->request_buffer;
    
    if(target>=NR_FAKE_DISKS || SCpnt->lun != 0) 
    {
	SCpnt->result =  DID_NO_CONNECT << 16;
	done(SCpnt);
	return 0;
    }
    
    if( SCrst[target] != 0 && !scsi_debug_lockup )
    {
        SCrst[target] = 0;
        memset(SCpnt->sense_buffer, 0, sizeof(SCpnt->sense_buffer));
        SCpnt->sense_buffer[0] = 0x70;
        SCpnt->sense_buffer[2] = UNIT_ATTENTION;
	SCpnt->result = (CHECK_CONDITION << 1);
	done(SCpnt);         
    }
    switch(*cmd){
    case REQUEST_SENSE:
	SCSI_LOG_LLQUEUE(3,printk("Request sense...\n"));
#ifndef DEBUG
	{ 
	    int i;
	    printk("scsi_debug: Requesting sense buffer (%p %p %p %d):", SCpnt, buff, done, bufflen);
	    for(i=0;i<12;i++) printk("%d ",sense_buffer[i]);
	    printk("\n");
	};
#endif
	memset(buff, 0, bufflen);
	memcpy(buff, sense_buffer, bufflen);
	memset(sense_buffer, 0, sizeof(sense_buffer));
	SCpnt->result = 0;
	done(SCpnt); 
	return 0;
    case ALLOW_MEDIUM_REMOVAL:
	if(cmd[4]) 
        {
            SCSI_LOG_LLQUEUE(2,printk("Medium removal inhibited..."));
        }
	else
        {
            SCSI_LOG_LLQUEUE(2,printk("Medium removal enabled..."));
        }
	scsi_debug_errsts = 0;
	break;
    case INQUIRY:
	SCSI_LOG_LLQUEUE(3,printk("Inquiry...(%p %d)\n", buff, bufflen));
	memset(buff, 0, bufflen);
	buff[0] = TYPE_DISK;
	buff[1] = DISK_REMOVEABLE(target) ? 0x80 : 0;  /* Removable disk */
	buff[2] = 1;
	buff[4] = 33 - 5;
	memcpy(&buff[8],"Foo Inc",7);
	memcpy(&buff[16],"XYZZY",5);
	memcpy(&buff[32],"1",1);
	scsi_debug_errsts = 0;
	break;
    case TEST_UNIT_READY:
	SCSI_LOG_LLQUEUE(3,printk("Test unit ready(%p %d)\n", buff, bufflen));
	if (buff)
	    memset(buff, 0, bufflen);
	scsi_debug_errsts = 0;
	break;
    case READ_CAPACITY:
	SCSI_LOG_LLQUEUE(3,printk("Read Capacity\n"));
	if(NR_REAL < 0) NR_REAL = (MINOR(SCpnt->request.rq_dev) >> 4) & 0x0f;
	memset(buff, 0, bufflen);
	buff[0] = (CAPACITY >> 24);
	buff[1] = (CAPACITY >> 16) & 0xff;
	buff[2] = (CAPACITY >> 8) & 0xff;
	buff[3] = CAPACITY & 0xff;
	buff[6] = 2; /* 512 byte sectors */
	scsi_debug_errsts = 0;
	break;
    case READ_10:
    case READ_6:
#ifdef DEBUG
	printk("Read...");
#endif
	if ((*cmd) == READ_10)
	    block = cmd[5] + (cmd[4] << 8) + (cmd[3] << 16) + (cmd[2] << 24); 
	else 
	    block = cmd[3] + (cmd[2] << 8) + ((cmd[1] & 0x1f) << 16);
	VERIFY_DEBUG(READ);
#if defined(SCSI_SETUP_LATENCY) || defined(SCSI_DATARATE)
    {
	int delay = SCSI_SETUP_LATENCY;
	
	delay += SCpnt->request.nr_sectors * SCSI_DATARATE;
	if(delay) usleep(delay);
    };
#endif
	
#ifdef DEBUG
	printk("(r%d)",SCpnt->request.nr_sectors);
#endif
	nbytes = bufflen;
	if(SCpnt->use_sg){
	    sgcount = 0;
	    sgpnt = (struct scatterlist *) buff;
	    buff = sgpnt[sgcount].address;
	    bufflen = sgpnt[sgcount].length;
	    bh = SCpnt->request.bh;
	};
	scsi_debug_errsts = 0;
	do{
	    VERIFY1_DEBUG(READ);
	    /* For the speedy test, we do not even want to fill the buffer with anything */
#ifdef CLEAR
	    memset(buff, 0, bufflen);
#endif
	    /* If this is block 0, then we want to read the partition table for this
	     * device.  Let's make one up */
	    if(block == 0) {
	    	int i;
                memset(buff, 0, bufflen);
		*((unsigned short *) (buff+510)) = 0xAA55;
		p = (struct partition* ) (buff + 0x1be);
		i = 0;
		while(starts[i+1]){
		    p->start_sect = starts[i];
		    p->nr_sects = starts[i+1] - starts [i];
		    p->sys_ind = 0x81;  /* Linux partition */
                    p->head       = (i == 0 ? 1 : 0);
                    p->sector     = 1;
                    p->cyl        = starts[i] / N_HEAD / N_SECTOR;
                    p->end_head   = N_HEAD - 1;
                    p->end_sector = N_SECTOR;
                    p->end_cyl    = starts[i + 1] / N_HEAD / N_SECTOR;
		    p++;
		    i++;
		};
		if (!npart) npart = i;
		scsi_debug_errsts = 0;
		break;
	    };
#ifdef DEBUG
	    if (SCpnt->use_sg) printk("Block %x (%d %d)\n",block, SCpnt->request.nr_sectors,
				      SCpnt->request.current_nr_sectors);
#endif
	    
#if 0
	    /* Simulate a disk change */
	    if(block == 0xfff0) {
		sense_buffer[0] = 0x70;
		sense_buffer[2] = UNIT_ATTENTION;
		starts[0] += 10;