53c78xx.c

GNU Mach 微内核源代码, 基于美国卡内基美隆大学的 Mach 研究项目

/* 
 * Function : static int normal_init(Scsi_Host_Template *tpnt, int board, 
 *	int chip, u32 base, int io_port, int irq, int dma, int pcivalid,
 *	unsigned char pci_bus, unsigned char pci_device_fn,
 *	long long options);
 *
 * Purpose : initializes a NCR53c7,8x0 based on base addresses,
 *	IRQ, and DMA channel.	
 *	
 *	Useful where a new NCR chip is backwards compatible with
 *	a supported chip, but the DEVICE ID has changed so it 
 *	doesn't show up when the autoprobe does a pcibios_find_device.
 *
 * Inputs : tpnt - Template for this SCSI adapter, board - board level
 *	product, chip - 810, 820, or 825, bus - PCI bus, device_fn -
 *	device and function encoding as used by PCI BIOS calls.
 * 
 * Returns : 0 on success, -1 on failure.
 *
 */

static int 
normal_init (Scsi_Host_Template *tpnt, int board, int chip, 
    u32 base, int io_port, int irq, int dma, int pci_valid, 
    unsigned char pci_bus, unsigned char pci_device_fn, long long options) {
    struct Scsi_Host *instance;
    struct NCR53c7x0_hostdata *hostdata;
    char chip_str[80];
    int script_len = 0, dsa_len = 0, size = 0, max_cmd_size = 0, 
	schedule_size = 0, ok = 0;
    void *tmp;

    options |= perm_options;

    switch (chip) {
    case 825:
    case 820:
    case 815:
    case 810:
	schedule_size = (tpnt->can_queue + 1) * 8 /* JUMP instruction size */;
	script_len = NCR53c8xx_script_len;
    	dsa_len = NCR53c8xx_dsa_len;
    	options |= OPTION_INTFLY;
    	sprintf (chip_str, "NCR53c%d", chip);
    	break;
    default:
    	printk("scsi-ncr53c7,8xx : unsupported SCSI chip %d\n", chip);
    	return -1;
    }

    printk("scsi-ncr53c7,8xx : %s at memory 0x%x, io 0x%x, irq %d",
    	chip_str, (unsigned) base, io_port, irq);
    if (dma == DMA_NONE)
    	printk("\n");
    else 
    	printk(", dma %d\n", dma);

    if ((chip / 100 == 8) && !pci_valid) 
	printk ("scsi-ncr53c7,8xx : for better reliability and performance, please use the\n" 
		"        PCI override instead.\n"
		"	 Syntax : ncr53c8{10,15,20,25}=pci,<bus>,<device>,<function>\n"
		"                 <bus> and <device> are usually 0.\n");

    if (options & OPTION_DEBUG_PROBE_ONLY) {
    	printk ("scsi-ncr53c7,8xx : probe only enabled, aborting initialization\n");
    	return -1;
    }

    max_cmd_size = sizeof(struct NCR53c7x0_cmd) + dsa_len +
    	/* Size of dynamic part of command structure : */
	2 * /* Worst case : we don't know if we need DATA IN or DATA out */
		( 2 * /* Current instructions per scatter/gather segment */ 
        	  tpnt->sg_tablesize + 
                  3 /* Current startup / termination required per phase */
		) *
	8 /* Each instruction is eight bytes */;

    /* Allocate fixed part of hostdata, dynamic part to hold appropriate
       SCSI SCRIPT(tm) plus a single, maximum-sized NCR53c7x0_cmd structure.

       We need a NCR53c7x0_cmd structure for scan_scsis() when we are 
       not loaded as a module, and when we're loaded as a module, we 
       can't use a non-dynamically allocated structure because modules
       are vmalloc()'d, which can allow structures to cross page 
       boundaries and breaks our physical/virtual address assumptions
       for DMA.

       So, we stick it past the end of our hostdata structure.

       ASSUMPTION : 
       	 Regardless of how many simultaneous SCSI commands we allow,
	 the probe code only executes a _single_ instruction at a time,
	 so we only need one here, and don't need to allocate NCR53c7x0_cmd
	 structures for each target until we are no longer in scan_scsis
	 and kmalloc() has become functional (memory_init() happens 
	 after all device driver initialization).
    */

    size = sizeof(struct NCR53c7x0_hostdata) + script_len + 
    /* Note that alignment will be guaranteed, since we put the command
       allocated at probe time after the fixed-up SCSI script, which 
       consists of 32 bit words, aligned on a 32 bit boundary.  But
       on a 64bit machine we need 8 byte alignment for hostdata->free, so
       we add in another 4 bytes to take care of potential misalignment
       */
	(sizeof(void *) - sizeof(u32)) + max_cmd_size + schedule_size;

    instance = scsi_register (tpnt, size);
    if (!instance)
	return -1;

    /* FIXME : if we ever support an ISA NCR53c7xx based board, we
       need to check if the chip is running in a 16 bit mode, and if so 
       unregister it if it is past the 16M (0x1000000) mark */
   	
    hostdata = (struct NCR53c7x0_hostdata *) 
    	instance->hostdata;
    hostdata->size = size;
    hostdata->script_count = script_len / sizeof(u32);
    hostdata = (struct NCR53c7x0_hostdata *) instance->hostdata;
    hostdata->board = board;
    hostdata->chip = chip;
    if ((hostdata->pci_valid = pci_valid)) {
	hostdata->pci_bus = pci_bus;
	hostdata->pci_device_fn = pci_device_fn;
    }

    /*
     * Being memory mapped is more desirable, since 
     *
     * - Memory accesses may be faster.
     *
     * - The destination and source address spaces are the same for 
     *	 all instructions, meaning we don't have to twiddle dmode or 
     *	 any other registers.
     *
     * So, we try for memory mapped, and if we don't get it,
     * we go for port mapped, and that failing we tell the user
     * it can't work.
     */

    if (base) {
	instance->base = (unsigned char *) (unsigned long) base;
	/* Check for forced I/O mapping */
    	if (!(options & OPTION_IO_MAPPED)) {
	    options |= OPTION_MEMORY_MAPPED;
	    ok = 1;
	}
    } else {
	options &= ~OPTION_MEMORY_MAPPED;
    }

    if (io_port) {
	instance->io_port = io_port;
	options |= OPTION_IO_MAPPED;
	ok = 1;
    } else {
	options &= ~OPTION_IO_MAPPED;
    }

    if (!ok) {
	printk ("scsi%d : not initializing, no I/O or memory mapping known \n",
	    instance->host_no);
	scsi_unregister (instance);
	return -1;
    }
    instance->irq = irq;
    instance->dma_channel = dma;

    hostdata->options = options;
    hostdata->dsa_len = dsa_len;
    hostdata->max_cmd_size = max_cmd_size;
    hostdata->num_cmds = 1;
    /* Initialize single command */
    tmp = (hostdata->script + hostdata->script_count);
    hostdata->free = ROUNDUP(tmp, void *);
    hostdata->free->real = tmp;
    hostdata->free->size = max_cmd_size;
    hostdata->free->free = NULL;
    hostdata->free->next = NULL;
    hostdata->extra_allocate = 0;

    /* Allocate command start code space */
    hostdata->schedule = (chip == 700 || chip == 70066) ?
	NULL : (u32 *) ((char *)hostdata->free + max_cmd_size);

/* 
 * For diagnostic purposes, we don't really care how fast things blaze.
 * For profiling, we want to access the 800ns resolution system clock,
 * using a 'C' call on the host processor.
 *
 * Therefore, there's no need for the NCR chip to directly manipulate
 * this data, and we should put it wherever is most convenient for 
 * Linux.
 */
    if (track_events) 
	hostdata->events = (struct NCR53c7x0_event *) (track_events ? 
	    vmalloc (sizeof (struct NCR53c7x0_event) * track_events) : NULL);
    else
	hostdata->events = NULL;

    if (hostdata->events) {
	memset ((void *) hostdata->events, 0, sizeof(struct NCR53c7x0_event) *
	    track_events);	
	hostdata->event_size = track_events;
	hostdata->event_index = 0;
    } else 
	hostdata->event_size = 0;

    return NCR53c7x0_init(instance);
}


/* 
 * Function : static int ncr_pci_init(Scsi_Host_Template *tpnt, int board, 
 *	int chip, int bus, int device_fn, long long options)
 *
 * Purpose : initializes a NCR53c800 family based on the PCI
 *	bus, device, and function location of it.  Allows 
 * 	reprogramming of latency timer and determining addresses
 *	and whether bus mastering, etc. are OK.
 *	
 *	Useful where a new NCR chip is backwards compatible with
 *	a supported chip, but the DEVICE ID has changed so it 
 *	doesn't show up when the autoprobe does a pcibios_find_device.
 *
 * Inputs : tpnt - Template for this SCSI adapter, board - board level
 *	product, chip - 810, 820, or 825, bus - PCI bus, device_fn -
 *	device and function encoding as used by PCI BIOS calls.
 * 
 * Returns : 0 on success, -1 on failure.
 *
 */

static int 
ncr_pci_init (Scsi_Host_Template *tpnt, int board, int chip, 
    unsigned char bus, unsigned char device_fn, long long options) {
    unsigned short vendor_id, device_id, command;
#ifdef LINUX_1_2
    unsigned long
#else
    unsigned int 
#endif
	base, io_port; 
    unsigned char irq, revision;
    int error, expected_chip;
    int expected_id = -1, max_revision = -1, min_revision = -1;
    int i;

    printk("scsi-ncr53c7,8xx : at PCI bus %d, device %d,  function %d\n",
	bus, (int) (device_fn & 0xf8) >> 3, 
    	(int) device_fn & 7);

    if (!pcibios_present()) {
	printk("scsi-ncr53c7,8xx : not initializing due to lack of PCI BIOS,\n"
	       "        try using memory, port, irq override instead.\n");
	return -1;
    }

    if ((error = pcibios_read_config_word (bus, device_fn, PCI_VENDOR_ID, 
	&vendor_id)) ||
	(error = pcibios_read_config_word (bus, device_fn, PCI_DEVICE_ID, 
	    &device_id)) ||
	(error = pcibios_read_config_word (bus, device_fn, PCI_COMMAND, 
	    &command)) ||
	(error = pcibios_read_config_dword (bus, device_fn, 
	    PCI_BASE_ADDRESS_0, &io_port)) || 
	(error = pcibios_read_config_dword (bus, device_fn, 
	    PCI_BASE_ADDRESS_1, &base)) ||
	(error = pcibios_read_config_byte (bus, device_fn, PCI_CLASS_REVISION,
	    &revision)) ||
	(error = pcibios_read_config_byte (bus, device_fn, PCI_INTERRUPT_LINE,
	    &irq))) {
	printk ("scsi-ncr53c7,8xx : error %s not initializing due to error reading configuration space\n"
		"	 perhaps you specified an incorrect PCI bus, device, or function.\n"
		, pcibios_strerror(error));
	return -1;
    }

    /* If any one ever clones the NCR chips, this will have to change */

    if (vendor_id != PCI_VENDOR_ID_NCR) {
	printk ("scsi-ncr53c7,8xx : not initializing, 0x%04x is not NCR vendor ID\n",
	    (int) vendor_id);
	return -1;
    }


    /* 
     * Bit 0 is the address space indicator and must be one for I/O
     * space mappings, bit 1 is reserved, discard them after checking
     * that they have the correct value of 1.
     */

    if (command & PCI_COMMAND_IO) { 
	if ((io_port & 3) != 1) {
	    printk ("scsi-ncr53c7,8xx : disabling I/O mapping since base address 0 (0x%x)\n"
    	    	    "        bits 0..1 indicate a non-IO mapping\n",
		(unsigned) io_port);
	    io_port = 0;
	} else
	    io_port &= PCI_BASE_ADDRESS_IO_MASK;
    } else {
    	io_port = 0;
    }

    if (command & PCI_COMMAND_MEMORY) {
	if ((base & PCI_BASE_ADDRESS_SPACE) != PCI_BASE_ADDRESS_SPACE_MEMORY) {
	    printk("scsi-ncr53c7,8xx : disabling memory mapping since base address 1\n"
		   "        contains a non-memory mapping\n");
	    base = 0;
	} else 
	    base &= PCI_BASE_ADDRESS_MEM_MASK;
    } else {
	base = 0;
    }
	
    if (!io_port && !base) {
	printk ("scsi-ncr53c7,8xx : not initializing, both I/O and memory mappings disabled\n");
	return -1;
    }
	
    if (!(command & PCI_COMMAND_MASTER)) {
	printk ("scsi-ncr53c7,8xx : not initializing, BUS MASTERING was disabled\n");
	return -1;
    }

    for (i = 0; i < NPCI_CHIP_IDS; ++i) {
	if (device_id == pci_chip_ids[i].pci_device_id) {
	    max_revision = pci_chip_ids[i].max_revision;
	    min_revision = pci_chip_ids[i].min_revision;
	    expected_chip = pci_chip_ids[i].chip;
	}
	if (chip == pci_chip_ids[i].chip)
	    expected_id = pci_chip_ids[i].pci_device_id;
    }

    if (chip && device_id != expected_id) 
	printk ("scsi-ncr53c7,8xx : warning : device id of 0x%04x doesn't\n"
                "                   match expected 0x%04x\n",
	    (unsigned int) device_id, (unsigned int) expected_id );
    
    if (max_revision != -1 && revision > max_revision) 
	printk ("scsi-ncr53c7,8xx : warning : revision of %d is greater than %d.\n",
	    (int) revision, max_revision);
    else if (min_revision != -1 && revision < min_revision)
	printk ("scsi-ncr53c7,8xx : warning : revision of %d is less than %d.\n",
	    (int) revision, min_revision);

    if (io_port && check_region (io_port, 128)) {
	printk ("scsi-ncr53c7,8xx : IO region 0x%x to 0x%x is in use\n",
	    (unsigned) io_port, (unsigned) io_port + 127);
	return -1;
    }

    return normal_init (tpnt, board, chip, (int) base, io_port, 
	(int) irq, DMA_NONE, 1, bus, device_fn, options);
}


/* 
 * Function : int NCR53c7xx_detect(Scsi_Host_Template *tpnt)
 *
 * Purpose : detects and initializes NCR53c7,8x0 SCSI chips
 *	that were autoprobed, overridden on the LILO command line, 
 *	or specified at compile time.
 *
 * Inputs : tpnt - template for this SCSI adapter
 * 
 * Returns : number of host adapters detected
 *
 */

int 
NCR53c7xx_detect(Scsi_Host_Template *tpnt) {
    int i;
    int current_override;
    int count;			/* Number of boards detected */
    unsigned char pci_bus, pci_device_fn;
    static short pci_index=0;	/* Device index to PCI BIOS calls */

#ifndef LINUX_1_2
    tpnt->proc_dir = &proc_scsi_ncr53c7xx;
#endif

    for (current_override = count = 0; current_override < OVERRIDE_LIMIT; 
	 ++current_override) {
	 if (overrides[current_override].pci ? 
	    !ncr_pci_init (tpnt, overrides[current_override].board,