mca.c

讲述linux的初始化过程

EXPORT_SYMBOL(mca_read_stored_pos);

/*--------------------------------------------------------------------*/

/**
 *	mca_read_pos - read POS register from card
 *	@slot: slot number to read from
 *	@reg:  register to read from
 *
 *	Fetch a POS value directly from the hardware to obtain the
 *	current value. This is much slower than mca_read_stored_pos and
 *	may not be invoked from interrupt context. It handles the
 *	deep magic required for onboard devices transparently.
 */

unsigned char mca_read_pos(int slot, int reg)
{
	unsigned int byte = 0;
	unsigned long flags;

	if(slot < 0 || slot >= MCA_NUMADAPTERS || mca_info == NULL) return 0;
	if(reg < 0 || reg >= 8) return 0;

	save_flags(flags);
	cli();

	/* Make sure motherboard setup is off */

	outb_p(0xff, MCA_MOTHERBOARD_SETUP_REG);

	/* Read in the appropriate register */

	if(slot == MCA_INTEGSCSI && mca_info->which_scsi) {

		/* Disable adapter setup, enable motherboard setup */

		outb_p(0, MCA_ADAPTER_SETUP_REG);
		outb_p(mca_info->which_scsi, MCA_MOTHERBOARD_SETUP_REG);

		byte = inb_p(MCA_POS_REG(reg));
		outb_p(0xff, MCA_MOTHERBOARD_SETUP_REG);
	} else if(slot == MCA_INTEGVIDEO) {

		/* Disable adapter setup, enable motherboard setup */

		outb_p(0, MCA_ADAPTER_SETUP_REG);
		outb_p(0xdf, MCA_MOTHERBOARD_SETUP_REG);

		byte = inb_p(MCA_POS_REG(reg));
		outb_p(0xff, MCA_MOTHERBOARD_SETUP_REG);
	} else if(slot == MCA_MOTHERBOARD) {

		/* Disable adapter setup, enable motherboard setup */
		outb_p(0, MCA_ADAPTER_SETUP_REG);
		outb_p(0x7f, MCA_MOTHERBOARD_SETUP_REG);

		byte = inb_p(MCA_POS_REG(reg));
		outb_p(0xff, MCA_MOTHERBOARD_SETUP_REG);
	} else if(slot < MCA_MAX_SLOT_NR) {

		/* Make sure motherboard setup is off */

		outb_p(0xff, MCA_MOTHERBOARD_SETUP_REG);

		/* Read the appropriate register */

		outb_p(0x8|(slot&0xf), MCA_ADAPTER_SETUP_REG);
		byte = inb_p(MCA_POS_REG(reg));
		outb_p(0, MCA_ADAPTER_SETUP_REG);
	}

	/* Make sure the stored values are consistent, while we're here */

	mca_info->slot[slot].pos[reg] = byte;

	restore_flags(flags);

	return byte;
} /* mca_read_pos() */

EXPORT_SYMBOL(mca_read_pos);

/*--------------------------------------------------------------------*/

/**
 *	mca_write_pos - read POS register from card
 *	@slot: slot number to read from
 *	@reg:  register to read from
 *	@byte: byte to write to the POS registers
 *
 *	Store a POS value directly from the hardware. You should not
 *	normally need to use this function and should have a very good
 *	knowledge of MCA bus before you do so. Doing this wrongly can
 *	damage the hardware.
 *
 *	This function may not be used from interrupt context.
 *
 *	Note that this a technically a Bad Thing, as IBM tech stuff says
 *	you should only set POS values through their utilities.
 *	However, some devices such as the 3c523 recommend that you write
 *	back some data to make sure the configuration is consistent.
 *	I'd say that IBM is right, but I like my drivers to work.
 *
 *	This function can't do checks to see if multiple devices end up
 *	with the same resources, so you might see magic smoke if someone
 *	screws up.
 */

void mca_write_pos(int slot, int reg, unsigned char byte)
{
	unsigned long flags;

	if(slot < 0 || slot >= MCA_MAX_SLOT_NR)
		return;
	if(reg < 0 || reg >= 8)
		return;
	if(mca_info == NULL)
		return;

	save_flags(flags);
	cli();

	/* Make sure motherboard setup is off */

	outb_p(0xff, MCA_MOTHERBOARD_SETUP_REG);

	/* Read in the appropriate register */

	outb_p(0x8|(slot&0xf), MCA_ADAPTER_SETUP_REG);
	outb_p(byte, MCA_POS_REG(reg));
	outb_p(0, MCA_ADAPTER_SETUP_REG);

	restore_flags(flags);

	/* Update the global register list, while we have the byte */

	mca_info->slot[slot].pos[reg] = byte;
} /* mca_write_pos() */

EXPORT_SYMBOL(mca_write_pos);

/*--------------------------------------------------------------------*/

/**
 *	mca_set_adapter_name - Set the description of the card
 *	@slot: slot to name
 *	@name: text string for the namen
 *
 *	This function sets the name reported via /proc for this
 *	adapter slot. This is for user information only. Setting a
 *	name deletes any previous name.
 */

void mca_set_adapter_name(int slot, char* name)
{
	if(mca_info == NULL) return;

	if(slot >= 0 && slot < MCA_NUMADAPTERS) {
		if(name != NULL) {
			strncpy(mca_info->slot[slot].name, name,
				sizeof(mca_info->slot[slot].name)-1);
			mca_info->slot[slot].name[
				sizeof(mca_info->slot[slot].name)-1] = 0;
		} else {
			mca_info->slot[slot].name[0] = 0;
		}
	}
}

EXPORT_SYMBOL(mca_set_adapter_name);

/**
 *	mca_set_adapter_procfn - Set the /proc callback
 *	@slot: slot to configure
 *	@procfn: callback function to call for /proc
 *	@dev: device information passed to the callback
 *
 *	This sets up an information callback for /proc/mca/slot?.  The
 *	function is called with the buffer, slot, and device pointer (or
 *	some equally informative context information, or nothing, if you
 *	prefer), and is expected to put useful information into the
 *	buffer.  The adapter name, ID, and POS registers get printed
 *	before this is called though, so don't do it again.
 *
 *	This should be called with a %NULL @procfn when a module
 *	unregisters, thus preventing kernel crashes and other such
 *	nastiness.
 */

void mca_set_adapter_procfn(int slot, MCA_ProcFn procfn, void* dev)
{
	if(mca_info == NULL) return;

	if(slot >= 0 && slot < MCA_NUMADAPTERS) {
		mca_info->slot[slot].procfn = procfn;
		mca_info->slot[slot].dev = dev;
	}
}

EXPORT_SYMBOL(mca_set_adapter_procfn);

/**
 *	mca_is_adapter_used - check if claimed by driver
 *	@slot:	slot to check
 *
 *	Returns 1 if the slot has been claimed by a driver
 */

int mca_is_adapter_used(int slot)
{
	return mca_info->slot[slot].driver_loaded;
}

EXPORT_SYMBOL(mca_is_adapter_used);

/**
 *	mca_mark_as_used - claim an MCA device
 *	@slot:	slot to claim
 *	FIXME:  should we make this threadsafe
 *
 *	Claim an MCA slot for a device driver. If the
 *	slot is already taken the function returns 1,
 *	if it is not taken it is claimed and 0 is
 *	returned.
 */

int mca_mark_as_used(int slot)
{
	if(mca_info->slot[slot].driver_loaded) return 1;
	mca_info->slot[slot].driver_loaded = 1;
	return 0;
}

EXPORT_SYMBOL(mca_mark_as_used);

/**
 *	mca_mark_as_unused - release an MCA device
 *	@slot:	slot to claim
 *
 *	Release the slot for other drives to use.
 */

void mca_mark_as_unused(int slot)
{
	mca_info->slot[slot].driver_loaded = 0;
}

EXPORT_SYMBOL(mca_mark_as_unused);

/**
 *	mca_get_adapter_name - get the adapter description
 *	@slot:	slot to query
 *
 *	Return the adapter description if set. If it has not been
 *	set or the slot is out range then return NULL.
 */

char *mca_get_adapter_name(int slot)
{
	if(mca_info == NULL) return 0;

	if(slot >= 0 && slot < MCA_NUMADAPTERS) {
		return mca_info->slot[slot].name;
	}

	return 0;
}

EXPORT_SYMBOL(mca_get_adapter_name);

/**
 *	mca_isadapter - check if the slot holds an adapter
 *	@slot:	slot to query
 *
 *	Returns zero if the slot does not hold an adapter, non zero if
 *	it does.
 */

int mca_isadapter(int slot)
{
	if(mca_info == NULL) return 0;

	if(slot >= 0 && slot < MCA_NUMADAPTERS) {
		return ((mca_info->slot[slot].status == MCA_ADAPTER_NORMAL)
			|| (mca_info->slot[slot].status == MCA_ADAPTER_DISABLED));
	}

	return 0;
}

EXPORT_SYMBOL(mca_isadapter);


/**
 *	mca_isadapter - check if the slot holds an adapter
 *	@slot:	slot to query
 *
 *	Returns a non zero value if the slot holds an enabled adapter
 *	and zero for any other case.
 */

int mca_isenabled(int slot)
{
	if(mca_info == NULL) return 0;

	if(slot >= 0 && slot < MCA_NUMADAPTERS) {
		return (mca_info->slot[slot].status == MCA_ADAPTER_NORMAL);
	}

	return 0;
}

EXPORT_SYMBOL(mca_isenabled);

/*--------------------------------------------------------------------*/

#ifdef CONFIG_PROC_FS

int get_mca_info(char *page, char **start, off_t off,
				 int count, int *eof, void *data)
{
	int i, j, len = 0;

	if(MCA_bus && mca_info != NULL) {
		/* Format POS registers of eight MCA slots */

		for(i=0; i<MCA_MAX_SLOT_NR; i++) {
			len += sprintf(page+len, "Slot %d: ", i+1);
			for(j=0; j<8; j++)
				len += sprintf(page+len, "%02x ", mca_info->slot[i].pos[j]);
			len += sprintf(page+len, " %s\n", mca_info->slot[i].name);
		}

		/* Format POS registers of integrated video subsystem */

		len += sprintf(page+len, "Video : ");
		for(j=0; j<8; j++)
			len += sprintf(page+len, "%02x ", mca_info->slot[MCA_INTEGVIDEO].pos[j]);
		len += sprintf(page+len, " %s\n", mca_info->slot[MCA_INTEGVIDEO].name);

		/* Format POS registers of integrated SCSI subsystem */

		len += sprintf(page+len, "SCSI  : ");
		for(j=0; j<8; j++)
			len += sprintf(page+len, "%02x ", mca_info->slot[MCA_INTEGSCSI].pos[j]);
		len += sprintf(page+len, " %s\n", mca_info->slot[MCA_INTEGSCSI].name);

		/* Format POS registers of motherboard */

		len += sprintf(page+len, "Planar: ");
		for(j=0; j<8; j++)
			len += sprintf(page+len, "%02x ", mca_info->slot[MCA_MOTHERBOARD].pos[j]);
		len += sprintf(page+len, " %s\n", mca_info->slot[MCA_MOTHERBOARD].name);
	} else {
		/* Leave it empty if MCA not detected - this should *never*
		 * happen!
		 */
	}

	if (len <= off+count) *eof = 1;
	*start = page + off;
	len -= off;
	if (len>count) len = count;
	if (len<0) len = 0;
	return len;
}

/*--------------------------------------------------------------------*/

static int mca_default_procfn(char* buf, struct MCA_adapter *p)
{
	int len = 0, i;
	int slot = p - mca_info->slot;

	/* Print out the basic information */

	if(slot < MCA_MAX_SLOT_NR) {
		len += sprintf(buf+len, "Slot: %d\n", slot+1);
	} else if(slot == MCA_INTEGSCSI) {
		len += sprintf(buf+len, "Integrated SCSI Adapter\n");
	} else if(slot == MCA_INTEGVIDEO) {
		len += sprintf(buf+len, "Integrated Video Adapter\n");
	} else if(slot == MCA_MOTHERBOARD) {
		len += sprintf(buf+len, "Motherboard\n");
	}
	if(p->name[0]) {

		/* Drivers might register a name without /proc handler... */

		len += sprintf(buf+len, "Adapter Name: %s\n",
			p->name);
	} else {
		len += sprintf(buf+len, "Adapter Name: Unknown\n");
	}
	len += sprintf(buf+len, "Id: %02x%02x\n",
		p->pos[1], p->pos[0]);
	len += sprintf(buf+len, "Enabled: %s\nPOS: ",
		mca_isenabled(slot) ? "Yes" : "No");
	for(i=0; i<8; i++) {
		len += sprintf(buf+len, "%02x ", p->pos[i]);
	}
	len += sprintf(buf+len, "\nDriver Installed: %s",
		mca_is_adapter_used(slot) ? "Yes" : "No");
	buf[len++] = '\n';
	buf[len] = 0;

	return len;
} /* mca_default_procfn() */

static int get_mca_machine_info(char* page, char **start, off_t off,
				 int count, int *eof, void *data)
{
	int len = 0;

	len += sprintf(page+len, "Model Id: 0x%x\n", machine_id);
	len += sprintf(page+len, "Submodel Id: 0x%x\n", machine_submodel_id);
	len += sprintf(page+len, "BIOS Revision: 0x%x\n", BIOS_revision);

	if (len <= off+count) *eof = 1;
	*start = page + off;
	len -= off;
	if (len>count) len = count;
	if (len<0) len = 0;
	return len;
}

static int mca_read_proc(char *page, char **start, off_t off,
				 int count, int *eof, void *data)
{
	struct MCA_adapter *p = (struct MCA_adapter *)data;
	int len = 0;

	/* Get the standard info */

	len = mca_default_procfn(page, p);

	/* Do any device-specific processing, if there is any */

	if(p->procfn) {
		len += p->procfn(page+len, p-mca_info->slot, p->dev);
	}
	if (len <= off+count) *eof = 1;
	*start = page + off;
	len -= off;
	if (len>count) len = count;
	if (len<0) len = 0;
	return len;
} /* mca_read_proc() */

/*--------------------------------------------------------------------*/

void __init mca_do_proc_init(void)
{
	int i;
	struct proc_dir_entry *proc_mca;
	struct proc_dir_entry* node = NULL;
	struct MCA_adapter *p;

	if(mca_info == NULL) return;	/* Should never happen */

	proc_mca = proc_mkdir("mca", &proc_root);
	create_proc_read_entry("pos",0,proc_mca,get_mca_info,NULL);
	create_proc_read_entry("machine",0,proc_mca,get_mca_machine_info,NULL);

	/* Initialize /proc/mca entries for existing adapters */

	for(i = 0; i < MCA_NUMADAPTERS; i++) {
		p = &mca_info->slot[i];
		p->procfn = 0;

		if(i < MCA_MAX_SLOT_NR) sprintf(p->procname,"slot%d", i+1);
		else if(i == MCA_INTEGVIDEO) sprintf(p->procname,"video");
		else if(i == MCA_INTEGSCSI) sprintf(p->procname,"scsi");
		else if(i == MCA_MOTHERBOARD) sprintf(p->procname,"planar");

		if(!mca_isadapter(i)) continue;

		node = create_proc_read_entry(p->procname, 0, proc_mca,
						mca_read_proc, (void *)p);

		if(node == NULL) {
			printk("Failed to allocate memory for MCA proc-entries!");
			return;
		}
	}

} /* mca_do_proc_init() */

#endif