/*
 * 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, 2000,2002-2007 Silicon Graphics, Inc. All rights reserved.
 */

#include <linux/types.h>
#include <linux/interrupt.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 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;

        if (is_shub1()) {
                SAL_CALL_NOLOCK(ret_stuff, SN_SAL_HUB_ERROR_INTERRUPT,
                        (u64) nasid, 0, 0, 0, 0, 0, 0);

                if ((int)ret_stuff.v0)
                        panic("%s: Fatal %s Error", __func__,
                                ((nasid & 1) ? "TIO" : "HUBII"));

                if (!(nasid & 1)) /* Not a TIO, handle CRB errors */
                        (void)hubiio_crb_error_handler(hubdev_info);
        } else
                if (nasid & 1) {        /* TIO errors */
                        SAL_CALL_NOLOCK(ret_stuff, SN_SAL_HUB_ERROR_INTERRUPT,
                                (u64) nasid, 0, 0, 0, 0, 0, 0);

                        if ((int)ret_stuff.v0)
                                panic("%s: Fatal TIO Error", __func__);
                } else
                        bte_error_handler((unsigned long)NODEPDA(nasid_to_cnodeid(nasid)));

        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)
                cpu_relax();

}

/*
 * 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, hub_eint_handler, IRQF_SHARED,
                        "SN_hub_error", hubdev_info)) {
                printk(KERN_ERR "hub_error_init: Failed to request_irq for 0x%p\n",
                    hubdev_info);
                return;
        }
        sn_set_err_irq_affinity(SGI_II_ERROR);
}


/*
 * 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, IRQF_SHARED, "SN_TIO_error",
             (void *)hubdev_info)) {
                printk("ice_error_init: request_irq() error hubdev_info 0x%p\n",
                       hubdev_info);
                return;
        }
        sn_set_err_irq_affinity(SGI_TIO_ERROR);
}