hwc_rw.c

讲述linux的初始化过程

	int retval = 0;

	subvec = start;

	while (((void *) subvec) < end) {
		subvec = find_gds_subvector (
					 subvec, end, GDS_KEY_SelfDefTextMsg);
		if (!subvec)
			break;
		subvec_data = (gds_subvector_t *)
		    (((unsigned long) subvec) +
		     sizeof (gds_subvector_t));
		subvec_end = (void *)
		    (((unsigned long) subvec) + subvec->length);
		retval += eval_selfdeftextmsg (subvec_data, subvec_end);
		subvec = (gds_subvector_t *) subvec_end;
	}

	return retval;
}

inline static int 
eval_cpmsu (gds_vector_t * start, void *end)
{
	gds_vector_t *vec;
	gds_subvector_t *vec_data;
	void *vec_end;
	int retval = 0;

	vec = start;

	while (((void *) vec) < end) {
		vec = find_gds_vector (vec, end, GDS_ID_TextCmd);
		if (!vec)
			break;
		vec_data = (gds_subvector_t *)
		    (((unsigned long) vec) + sizeof (gds_vector_t));
		vec_end = (void *) (((unsigned long) vec) + vec->length);
		retval += eval_textcmd (vec_data, vec_end);
		vec = (gds_vector_t *) vec_end;
	}

	return retval;
}

inline static int 
eval_mdsmu (gds_vector_t * start, void *end)
{
	gds_vector_t *vec;
	gds_vector_t *vec_data;
	void *vec_end;
	int retval = 0;

	vec = find_gds_vector (start, end, GDS_ID_CPMSU);
	if (vec) {
		vec_data = (gds_vector_t *)
		    (((unsigned long) vec) + sizeof (gds_vector_t));
		vec_end = (void *) (((unsigned long) vec) + vec->length);
		retval = eval_cpmsu (vec_data, vec_end);
	}
	return retval;
}

inline static int 
eval_evbuf (gds_vector_t * start, void *end)
{
	gds_vector_t *vec;
	gds_vector_t *vec_data;
	void *vec_end;
	int retval = 0;

	vec = find_gds_vector (start, end, GDS_ID_MDSMU);
	if (vec) {
		vec_data = (gds_vector_t *)
		    (((unsigned long) vec) + sizeof (gds_vector_t));
		vec_end = (void *) (((unsigned long) vec) + vec->length);
		retval = eval_mdsmu (vec_data, vec_end);
	}
	return retval;
}

static int 
process_evbufs (void *start, void *end)
{
	int retval = 0;
	evbuf_t *evbuf;
	void *evbuf_end;
	gds_vector_t *evbuf_data;

	evbuf = (evbuf_t *) start;
	while (((void *) evbuf) < end) {
		evbuf_data = (gds_vector_t *)
		    (((unsigned long) evbuf) + sizeof (evbuf_t));
		evbuf_end = (void *) (((unsigned long) evbuf) + evbuf->length);
		switch (evbuf->type) {
		case ET_OpCmd:
		case ET_CntlProgOpCmd:
		case ET_PMsgCmd:
#ifdef DUMP_HWCB_INPUT

			internal_print (
					       DELAYED_WRITE,
					       HWC_RW_PRINT_HEADER
					       "event buffer "
					   "at 0x%x up to 0x%x, length: %d\n",
					       (unsigned long) evbuf,
					       (unsigned long) (evbuf_end - 1),
					       evbuf->length);
			dump_storage_area ((void *) evbuf, evbuf->length);
#endif
			retval += eval_evbuf (evbuf_data, evbuf_end);
			break;
		case ET_StateChange:

			retval = -ENOSYS;
			break;
		default:
			printk (
				       KERN_WARNING
				       HWC_RW_PRINT_HEADER
				       "unconditional read: "
				       "unknown event buffer found, "
				       "type 0x%x",
				       evbuf->type);
			retval = -ENOSYS;
		}
		evbuf = (evbuf_t *) evbuf_end;
	}
	return retval;
}

static int 
unconditional_read_1 (void)
{
	unsigned short int condition_code;
	read_hwcb_t *hwcb = (read_hwcb_t *) hwc_data.page;
	int retval;

	if ((!hwc_data.read_prio) && (!hwc_data.read_nonprio))
		return -EOPNOTSUPP;

	if (hwc_data.current_servc)
		return -EBUSY;

	memset (hwcb, 0x00, PAGE_SIZE);
	memcpy (hwcb, &read_hwcb_template, sizeof (read_hwcb_t));

	condition_code = service_call (HWC_CMDW_READDATA, hwc_data.page);

#ifdef DUMP_HWC_READ_ERROR
	if (condition_code == HWC_NOT_OPERATIONAL)
		__asm__ ("LHI 1,0xe40\n\t"
			 "L 2,0(0,%0)\n\t"
			 "LRA 3,0(0,%1)\n\t"
			 "J .+0 \n\t"
	      :
	      :	 "a" (&condition_code), "a" (hwc_data.page)
	      :	 "1", "2", "3");
#endif

	switch (condition_code) {
	case HWC_COMMAND_INITIATED:
		hwc_data.current_servc = HWC_CMDW_READDATA;
		hwc_data.current_hwcb = hwc_data.page;
		retval = condition_code;
		break;
	case HWC_BUSY:
		retval = -EBUSY;
		break;
	default:
		retval = -EIO;
	}

	return retval;
}

static int 
unconditional_read_2 (void)
{
	read_hwcb_t *hwcb = (read_hwcb_t *) hwc_data.page;

#ifdef DUMP_HWC_READ_ERROR
	if ((hwcb->response_code != 0x0020) &&
	    (hwcb->response_code != 0x0220) &&
	    (hwcb->response_code != 0x60F0) &&
	    (hwcb->response_code != 0x62F0))
		__asm__ ("LHI 1,0xe41\n\t"
			 "LRA 2,0(0,%0)\n\t"
			 "L 3,0(0,%1)\n\t"
			 "J .+0\n\t"
	      :
	      :	 "a" (hwc_data.page), "a" (&(hwcb->response_code))
	      :	 "1", "2", "3");
#endif

	hwc_data.current_servc = 0;
	hwc_data.current_hwcb = NULL;

	switch (hwcb->response_code) {

	case 0x0020:
	case 0x0220:
		return process_evbufs (
		     (void *) (((unsigned long) hwcb) + sizeof (read_hwcb_t)),
			    (void *) (((unsigned long) hwcb) + hwcb->length));

	case 0x60F0:
	case 0x62F0:
		return 0;

	case 0x0100:
		internal_print (
				       IMMEDIATE_WRITE,
				       HWC_RW_PRINT_HEADER
			 "unconditional read: HWCB boundary violation - this "
			 "must not occur in a correct driver, please contact "
				       "author\n");
		return -EIO;

	case 0x0300:
		internal_print (
				       IMMEDIATE_WRITE,
				       HWC_RW_PRINT_HEADER
				       "unconditional read: "
			"insufficient HWCB length - this must not occur in a "
				   "correct driver, please contact author\n");
		return -EIO;

	case 0x01F0:
		internal_print (
				       IMMEDIATE_WRITE,
				       HWC_RW_PRINT_HEADER
				       "unconditional read: "
			 "invalid command - this must not occur in a correct "
				       "driver, please contact author\n");
		return -EIO;

	case 0x40F0:
		internal_print (
				       IMMEDIATE_WRITE,
				       HWC_RW_PRINT_HEADER
			   "unconditional read: invalid function code - this "
			 "must not occur in a correct driver, please contact "
				       "author\n");
		return -EIO;

	case 0x70F0:
		internal_print (
				       IMMEDIATE_WRITE,
				       HWC_RW_PRINT_HEADER
			  "unconditional read: invalid selection mask - this "
			 "must not occur in a correct driver, please contact "
				       "author\n");
		return -EIO;

	case 0x0040:
		internal_print (
				       IMMEDIATE_WRITE,
				       HWC_RW_PRINT_HEADER
			    "unconditional read: HWC equipment check - don't "
				       "know how to handle this case\n");
		return -EIO;

	default:
		internal_print (
				       IMMEDIATE_WRITE,
				       HWC_RW_PRINT_HEADER
			"unconditional read: invalid response code %x - this "
			 "must not occur in a correct driver, please contact "
				       "author\n",
				       hwcb->response_code);
		return -EIO;
	}
}

static int 
write_event_mask_1 (void)
{
	unsigned int condition_code;
	int retval;

	memcpy (hwc_data.page, &init_hwcb_template, sizeof (init_hwcb_t));

	condition_code = service_call (HWC_CMDW_WRITEMASK, hwc_data.page);

#ifdef DUMP_HWC_INIT_ERROR

	if (condition_code != HWC_COMMAND_INITIATED)
		__asm__ ("LHI 1,0xe10\n\t"
			 "L 2,0(0,%0)\n\t"
			 "LRA 3,0(0,%1)\n\t"
			 "J .+0\n\t"
	      :
	      :	 "a" (&condition_code), "a" (hwc_data.page)
	      :	 "1", "2", "3");
#endif

	switch (condition_code) {
	case HWC_COMMAND_INITIATED:
		hwc_data.current_servc = HWC_CMDW_WRITEMASK;
		hwc_data.current_hwcb = hwc_data.page;
		retval = condition_code;
		break;
	case HWC_BUSY:
		retval = -EBUSY;
		break;
	default:
		retval = -EIO;
	}

	return retval;
}

static int 
write_event_mask_2 (void)
{
	init_hwcb_t *hwcb = (init_hwcb_t *) hwc_data.page;
	int retval = 0;

	if (hwcb->hwc_receive_mask & ET_Msg_Mask)
		hwc_data.write_nonprio = 1;

	if (hwcb->hwc_receive_mask & ET_PMsgCmd_Mask)
		hwc_data.write_prio = 1;

	if (hwcb->hwc_send_mask & ET_OpCmd_Mask)
		hwc_data.read_nonprio = 1;

	if (hwcb->hwc_send_mask & ET_PMsgCmd_Mask)
		hwc_data.read_nonprio = 1;

	if ((hwcb->response_code != 0x0020) ||
	    (!hwc_data.write_nonprio) ||
	    ((!hwc_data.read_nonprio) && (!hwc_data.read_prio)))
#ifdef DUMP_HWC_INIT_ERROR
		__asm__ ("LHI 1,0xe11\n\t"
			 "LRA 2,0(0,%0)\n\t"
			 "L 3,0(0,%1)\n\t"
			 "J .+0\n\t"
	      :
	      :	 "a" (hwcb), "a" (&(hwcb->response_code))
	      :	 "1", "2", "3");
#else
		retval = -EIO
#endif

		    hwc_data.current_servc = 0;
	hwc_data.current_hwcb = NULL;

	return retval;
}

static int 
set_hwc_ioctls (hwc_ioctls_t * ioctls, char correct)
{
	int retval = 0;
	hwc_ioctls_t tmp;

	if (ioctls->width_htab > MAX_MESSAGE_SIZE) {
		if (correct)
			tmp.width_htab = MAX_MESSAGE_SIZE;
		else
			retval = -EINVAL;
	} else
		tmp.width_htab = ioctls->width_htab;

	tmp.echo = ioctls->echo;

	if (ioctls->columns > MAX_MESSAGE_SIZE) {
		if (correct)
			tmp.columns = MAX_MESSAGE_SIZE;
		else
			retval = -EINVAL;
	} else
		tmp.columns = ioctls->columns;

	switch (ioctls->code) {
	case CODE_EBCDIC:
	case CODE_ASCII:
		tmp.code = ioctls->code;
		break;
	default:
		if (correct)
			tmp.code = CODE_ASCII;
		else
			retval = -EINVAL;
	}

	tmp.final_nl = ioctls->final_nl;

	if (ioctls->max_hwcb < 2) {
		if (correct)
			tmp.max_hwcb = 2;
		else
			retval = -EINVAL;
	} else
		tmp.max_hwcb = ioctls->max_hwcb;

	tmp.tolower = ioctls->tolower;

	if (ioctls->kmem_hwcb > ioctls->max_hwcb) {
		if (correct)
			tmp.kmem_hwcb = ioctls->max_hwcb;
		else
			retval = -EINVAL;
	} else
		tmp.kmem_hwcb = ioctls->kmem_hwcb;

	if (ioctls->kmem_hwcb > MAX_KMEM_PAGES) {
		if (correct)
			ioctls->kmem_hwcb = MAX_KMEM_PAGES;
		else
			retval = -EINVAL;
	}
	if (ioctls->kmem_hwcb < 2) {
		if (correct)
			ioctls->kmem_hwcb = 2;
		else
			retval = -EINVAL;
	}
	tmp.delim = ioctls->delim;

	if (!(retval < 0))
		hwc_data.ioctls = tmp;

	return retval;
}

int 
hwc_init (void)
{
	int retval;
#ifdef BUFFER_STRESS_TEST

	init_hwcb_t *hwcb;
	int i;

#endif

#ifdef CONFIG_3215
	if (MACHINE_IS_VM)
		return 0;
#endif

	spin_lock_init (&hwc_data.lock);

	retval = write_event_mask_1 ();
	if (retval < 0)
		return retval;

#ifdef USE_VM_DETECTION

	if (MACHINE_IS_VM) {

		if (hwc_data.init_ioctls.columns > 76)
			hwc_data.init_ioctls.columns = 76;
		hwc_data.init_ioctls.tolower = 1;
		if (!hwc_data.init_ioctls.delim)
			hwc_data.init_ioctls.delim = DEFAULT_CASE_DELIMITER;
	} else {
		hwc_data.init_ioctls.tolower = 0;
		hwc_data.init_ioctls.delim = 0;
	}
#endif
	retval = set_hwc_ioctls (&hwc_data.init_ioctls, 1);

	hwc_data.kmem_start = (unsigned long)
	    alloc_bootmem_pages (hwc_data.ioctls.kmem_hwcb * PAGE_SIZE);
	hwc_data.kmem_end = hwc_data.kmem_start +
	    hwc_data.ioctls.kmem_hwcb * PAGE_SIZE - 1;

	ctl_set_bit (0, 9);

#ifdef BUFFER_STRESS_TEST

	internal_print (
			       DELAYED_WRITE,
			       HWC_RW_PRINT_HEADER
			       "use %i bytes for buffering.\n",
			       hwc_data.ioctls.kmem_hwcb * PAGE_SIZE);
	for (i = 0; i < 500; i++) {
		hwcb = (init_hwcb_t *) BUF_HWCB;
		internal_print (
				       DELAYED_WRITE,
				       HWC_RW_PRINT_HEADER
			  "This is stress test message #%i, free: %i bytes\n",
				       i,
			     MAX_HWCB_ROOM - (hwcb->length + sizeof (mto_t)));
	}

#endif

	return retval;
}

void 
do_hwc_interrupt (void)
{

	spin_lock (&hwc_data.lock);

	if (!hwc_data.current_servc) {

		unconditional_read_1 ();

	} else {

		switch (hwc_data.current_servc) {

		case HWC_CMDW_WRITEMASK:

			write_event_mask_2 ();
			break;

		case HWC_CMDW_WRITEDATA:

			write_event_data_2 ();
			break;

		case HWC_CMDW_READDATA:

			unconditional_read_2 ();
			break;
		}

		write_event_data_1 ();
	}

	wake_up_hwc_tty ();

	spin_unlock (&hwc_data.lock);
}

int 
hwc_ioctl (unsigned int cmd, unsigned long arg)
{
	hwc_ioctls_t tmp = hwc_data.ioctls;
	int retval = 0;
	unsigned long flags;
	unsigned int obuf;

	spin_lock_irqsave (&hwc_data.lock, flags);

	switch (cmd) {

	case TIOCHWCSHTAB:
		if (get_user (tmp.width_htab, (ioctl_htab_t *) arg))
			goto fault;
		break;

	case TIOCHWCSECHO:
		if (get_user (tmp.echo, (ioctl_echo_t *) arg))
			goto fault;
		break;

	case TIOCHWCSCOLS:
		if (get_user (tmp.columns, (ioctl_cols_t *) arg))
			goto fault;
		break;

	case TIOCHWCSCODE:
		if (get_user (tmp.code, (ioctl_code_t *) arg))
			goto fault;

		break;

	case TIOCHWCSNL:
		if (get_user (tmp.final_nl, (ioctl_nl_t *) arg))
			goto fault;
		break;

	case TIOCHWCSOBUF:
		if (get_user (obuf, (unsigned int *) arg))
			goto fault;
		if (obuf & 0xFFF)
			tmp.max_hwcb = (((obuf | 0xFFF) + 1) >> 12);
		else
			tmp.max_hwcb = (obuf >> 12);
		break;

	case TIOCHWCSCASE:
		if (get_user (tmp.tolower, (ioctl_case_t *) arg))
			goto fault;
		break;

	case TIOCHWCSDELIM:
		if (get_user (tmp.delim, (ioctl_delim_t *) arg))
			goto fault;
		break;

	case TIOCHWCSINIT:
		retval = set_hwc_ioctls (&hwc_data.init_ioctls, 1);
		break;

	case TIOCHWCGHTAB:
		if (put_user (tmp.width_htab, (ioctl_htab_t *) arg))
			goto fault;
		break;

	case TIOCHWCGECHO:
		if (put_user (tmp.echo, (ioctl_echo_t *) arg))
			goto fault;
		break;

	case TIOCHWCGCOLS:
		if (put_user (tmp.columns, (ioctl_cols_t *) arg))
			goto fault;
		break;

	case TIOCHWCGCODE:
		if (put_user (tmp.code, (ioctl_code_t *) arg))
			goto fault;

		break;

	case TIOCHWCGNL:
		if (put_user (tmp.final_nl, (ioctl_nl_t *) arg))
			goto fault;
		break;

	case TIOCHWCGOBUF:
		if (put_user (tmp.max_hwcb, (ioctl_obuf_t *) arg))
			goto fault;
		break;

	case TIOCHWCGKBUF:
		if (put_user (tmp.kmem_hwcb, (ioctl_obuf_t *) arg))
			goto fault;
		break;

	case TIOCHWCGCASE:
		if (put_user (tmp.tolower, (ioctl_case_t *) arg))
			goto fault;
		break;

	case TIOCHWCGDELIM:
		if (put_user (tmp.delim, (ioctl_delim_t *) arg))
			goto fault;
		break;
#if 0

	case TIOCHWCGINIT:
		if (put_user (&hwc_data.init_ioctls, (hwc_ioctls_t *) arg))
			goto fault;
		break;

	case TIOCHWCGCURR:
		if (put_user (&hwc_data.ioctls, (hwc_ioctls_t *) arg))
			goto fault;
		break;
#endif

	default:
		goto noioctlcmd;
	}

	if (_IOC_DIR (cmd) == _IOC_WRITE)
		retval = set_hwc_ioctls (&tmp, 0);

	goto out;

      fault:
	retval = -EFAULT;
	goto out;
      noioctlcmd:
	retval = -ENOIOCTLCMD;
      out:
	spin_unlock_irqrestore (&hwc_data.lock, flags);
	return retval;
}