/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1992 - 1997, 2000,2002-2004 Silicon Graphics, Inc. All rights reserved.
 */

#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <asm/delay.h>
#include <asm/sn/sn_sal.h>
#include "ioerror.h"
#include <asm/sn/addrs.h>
#include <asm/sn/shubio.h>
#include <asm/sn/geo.h>
#include "xtalk/xwidgetdev.h"
#include "xtalk/hubdev.h"
#include <asm/sn/bte.h>

void hubiio_crb_error_handler(struct hubdev_info *hubdev_info);
extern void bte_crb_error_handler(cnodeid_t, int, int, ioerror_t *,
				  int);
static irqreturn_t hub_eint_handler(int irq, void *arg, struct pt_regs *ep)
{
	struct hubdev_info *hubdev_info;
	struct ia64_sal_retval ret_stuff;
	nasid_t nasid;

	ret_stuff.status = 0;
	ret_stuff.v0 = 0;
	hubdev_info = (struct hubdev_info *)arg;
	nasid = hubdev_info->hdi_nasid;
	SAL_CALL_NOLOCK(ret_stuff, SN_SAL_HUB_ERROR_INTERRUPT,
			(u64) nasid, 0, 0, 0, 0, 0, 0);

	if ((int)ret_stuff.v0)
		panic("hubii_eint_handler(): Fatal TIO Error");

	if (!(nasid & 1)) /* Not a TIO, handle CRB errors */
		(void)hubiio_crb_error_handler(hubdev_info);

	return IRQ_HANDLED;
}

/*
 * Free the hub CRB "crbnum" which encountered an error.
 * Assumption is, error handling was successfully done,
 * and we now want to return the CRB back to Hub for normal usage.
 *
 * In order to free the CRB, all that's needed is to de-allocate it
 *
 * Assumption:
 *      No other processor is mucking around with the hub control register.
 *      So, upper layer has to single thread this.
 */
void hubiio_crb_free(struct hubdev_info *hubdev_info, int crbnum)
{
	ii_icrb0_b_u_t icrbb;

	/*
	 * The hardware does NOT clear the mark bit, so it must get cleared
	 * here to be sure the error is not processed twice.
	 */
	icrbb.ii_icrb0_b_regval = REMOTE_HUB_L(hubdev_info->hdi_nasid,
					       IIO_ICRB_B(crbnum));
	icrbb.b_mark = 0;
	REMOTE_HUB_S(hubdev_info->hdi_nasid, IIO_ICRB_B(crbnum),
		     icrbb.ii_icrb0_b_regval);
	/*
	 * Deallocate the register wait till hub indicates it's done.
	 */
	REMOTE_HUB_S(hubdev_info->hdi_nasid, IIO_ICDR, (IIO_ICDR_PND | crbnum));
	while (REMOTE_HUB_L(hubdev_info->hdi_nasid, IIO_ICDR) & IIO_ICDR_PND)
		udelay(1);

}

/*
 * hubiio_crb_error_handler
 *
 *	This routine gets invoked when a hub gets an error 
 *	interrupt. So, the routine is running in interrupt context
 *	at error interrupt level.
 * Action:
 *	It's responsible for identifying ALL the CRBs that are marked
 *	with error, and process them. 
 *	
 * 	If you find the CRB that's marked with error, map this to the
 *	reason it caused error, and invoke appropriate error handler.
 *
 *	XXX Be aware of the information in the context register.
 *
 * NOTE:
 *	Use REMOTE_HUB_* macro instead of LOCAL_HUB_* so that the interrupt
 *	handler can be run on any node. (not necessarily the node 
 *	corresponding to the hub that encountered error).
 */

void hubiio_crb_error_handler(struct hubdev_info *hubdev_info)
{
	nasid_t nasid;
	ii_icrb0_a_u_t icrba;	/* II CRB Register A */
	ii_icrb0_b_u_t icrbb;	/* II CRB Register B */
	ii_icrb0_c_u_t icrbc;	/* II CRB Register C */
	ii_icrb0_d_u_t icrbd;	/* II CRB Register D */
	ii_icrb0_e_u_t icrbe;	/* II CRB Register D */
	int i;
	int num_errors = 0;	/* Num of errors handled */
	ioerror_t ioerror;

	nasid = hubdev_info->hdi_nasid;

	/*
	 * XXX - Add locking for any recovery actions
	 */
	/*
	 * Scan through all CRBs in the Hub, and handle the errors
	 * in any of the CRBs marked.
	 */
	for (i = 0; i < IIO_NUM_CRBS; i++) {
		/* Check this crb entry to see if it is in error. */
		icrbb.ii_icrb0_b_regval = REMOTE_HUB_L(nasid, IIO_ICRB_B(i));

		if (icrbb.b_mark == 0) {
			continue;
		}

		icrba.ii_icrb0_a_regval = REMOTE_HUB_L(nasid, IIO_ICRB_A(i));

		IOERROR_INIT(&ioerror);

		/* read other CRB error registers. */
		icrbc.ii_icrb0_c_regval = REMOTE_HUB_L(nasid, IIO_ICRB_C(i));
		icrbd.ii_icrb0_d_regval = REMOTE_HUB_L(nasid, IIO_ICRB_D(i));
		icrbe.ii_icrb0_e_regval = REMOTE_HUB_L(nasid, IIO_ICRB_E(i));

		IOERROR_SETVALUE(&ioerror, errortype, icrbb.b_ecode);

		/* Check if this error is due to BTE operation,
		 * and handle it separately.
		 */
		if (icrbd.d_bteop ||
		    ((icrbb.b_initiator == IIO_ICRB_INIT_BTE0 ||
		      icrbb.b_initiator == IIO_ICRB_INIT_BTE1) &&
		     (icrbb.b_imsgtype == IIO_ICRB_IMSGT_BTE ||
		      icrbb.b_imsgtype == IIO_ICRB_IMSGT_SN1NET))) {

			int bte_num;

			if (icrbd.d_bteop)
				bte_num = icrbc.c_btenum;
			else	/* b_initiator bit 2 gives BTE number */
				bte_num = (icrbb.b_initiator & 0x4) >> 2;

			hubiio_crb_free(hubdev_info, i);

			bte_crb_error_handler(nasid_to_cnodeid(nasid), bte_num,
					      i, &ioerror, icrbd.d_bteop);
			num_errors++;
			continue;
		}
	}
}

/*
 * Function	: hub_error_init
 * Purpose	: initialize the error handling requirements for a given hub.
 * Parameters	: cnode, the compact nodeid.
 * Assumptions	: Called only once per hub, either by a local cpu. Or by a
 *			remote cpu, when this hub is headless.(cpuless)
 * Returns	: None
 */
void hub_error_init(struct hubdev_info *hubdev_info)
{
	if (request_irq(SGI_II_ERROR, (void *)hub_eint_handler, SA_SHIRQ,
			"SN_hub_error", (void *)hubdev_info))
		printk("hub_error_init: Failed to request_irq for 0x%p\n",
		    hubdev_info);
	return;
}


/*
 * Function	: ice_error_init
 * Purpose	: initialize the error handling requirements for a given tio.
 * Parameters	: cnode, the compact nodeid.
 * Assumptions	: Called only once per tio.
 * Returns	: None
 */
void ice_error_init(struct hubdev_info *hubdev_info)
{
        if (request_irq
            (SGI_TIO_ERROR, (void *)hub_eint_handler, SA_SHIRQ, "SN_TIO_error",
             (void *)hubdev_info))
                printk("ice_error_init: request_irq() error hubdev_info 0x%p\n",
                       hubdev_info);
        return;
}