xpc_uv.c

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/*
 * 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) 2008-2009 Silicon Graphics, Inc.  All Rights Reserved.
 */

/*
 * Cross Partition Communication (XPC) uv-based functions.
 *
 *     Architecture specific implementation of common functions.
 *
 */

#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <asm/uv/uv_hub.h>
#if defined CONFIG_X86_64
#include <asm/uv/bios.h>
#include <asm/uv/uv_irq.h>
#elif defined CONFIG_IA64_GENERIC || defined CONFIG_IA64_SGI_UV
#include <asm/sn/intr.h>
#include <asm/sn/sn_sal.h>
#endif
#include "../sgi-gru/gru.h"
#include "../sgi-gru/grukservices.h"
#include "xpc.h"

#if defined CONFIG_IA64_GENERIC || defined CONFIG_IA64_SGI_UV
struct uv_IO_APIC_route_entry {
    __u64   vector      :  8,
        delivery_mode   :  3,
        dest_mode   :  1,
        delivery_status :  1,
        polarity    :  1,
        __reserved_1    :  1,
        trigger     :  1,
        mask        :  1,
        __reserved_2    : 15,
        dest        : 32;
};
#endif

static struct xpc_heartbeat_uv *xpc_heartbeat_uv;

#define XPC_ACTIVATE_MSG_SIZE_UV    (1 * GRU_CACHE_LINE_BYTES)
#define XPC_ACTIVATE_MQ_SIZE_UV     (4 * XP_MAX_NPARTITIONS_UV * \
                     XPC_ACTIVATE_MSG_SIZE_UV)
#define XPC_ACTIVATE_IRQ_NAME       "xpc_activate"

#define XPC_NOTIFY_MSG_SIZE_UV      (2 * GRU_CACHE_LINE_BYTES)
#define XPC_NOTIFY_MQ_SIZE_UV       (4 * XP_MAX_NPARTITIONS_UV * \
                     XPC_NOTIFY_MSG_SIZE_UV)
#define XPC_NOTIFY_IRQ_NAME     "xpc_notify"

static int xpc_mq_node = -1;

static struct xpc_gru_mq_uv *xpc_activate_mq_uv;
static struct xpc_gru_mq_uv *xpc_notify_mq_uv;

static int
xpc_setup_partitions_uv(void)
{
    short partid;
    struct xpc_partition_uv *part_uv;

    for (partid = 0; partid < XP_MAX_NPARTITIONS_UV; partid++) {
        part_uv = &xpc_partitions[partid].sn.uv;

        mutex_init(&part_uv->cached_activate_gru_mq_desc_mutex);
        spin_lock_init(&part_uv->flags_lock);
        part_uv->remote_act_state = XPC_P_AS_INACTIVE;
    }
    return 0;
}

static void
xpc_teardown_partitions_uv(void)
{
    short partid;
    struct xpc_partition_uv *part_uv;
    unsigned long irq_flags;

    for (partid = 0; partid < XP_MAX_NPARTITIONS_UV; partid++) {
        part_uv = &xpc_partitions[partid].sn.uv;

        if (part_uv->cached_activate_gru_mq_desc != NULL) {
            mutex_lock(&part_uv->cached_activate_gru_mq_desc_mutex);
            spin_lock_irqsave(&part_uv->flags_lock, irq_flags);
            part_uv->flags &= ~XPC_P_CACHED_ACTIVATE_GRU_MQ_DESC_UV;
            spin_unlock_irqrestore(&part_uv->flags_lock, irq_flags);
            kfree(part_uv->cached_activate_gru_mq_desc);
            part_uv->cached_activate_gru_mq_desc = NULL;
            mutex_unlock(&part_uv->
                     cached_activate_gru_mq_desc_mutex);
        }
    }
}

static int
xpc_get_gru_mq_irq_uv(struct xpc_gru_mq_uv *mq, int cpu, char *irq_name)
{
    int mmr_pnode = uv_blade_to_pnode(mq->mmr_blade);

#if defined CONFIG_X86_64
    mq->irq = uv_setup_irq(irq_name, cpu, mq->mmr_blade, mq->mmr_offset,
            UV_AFFINITY_CPU);
    if (mq->irq < 0)
        return mq->irq;

    mq->mmr_value = uv_read_global_mmr64(mmr_pnode, mq->mmr_offset);

#elif defined CONFIG_IA64_GENERIC || defined CONFIG_IA64_SGI_UV
    if (strcmp(irq_name, XPC_ACTIVATE_IRQ_NAME) == 0)
        mq->irq = SGI_XPC_ACTIVATE;
    else if (strcmp(irq_name, XPC_NOTIFY_IRQ_NAME) == 0)
        mq->irq = SGI_XPC_NOTIFY;
    else
        return -EINVAL;

    mq->mmr_value = (unsigned long)cpu_physical_id(cpu) << 32 | mq->irq;
    uv_write_global_mmr64(mmr_pnode, mq->mmr_offset, mq->mmr_value);
#else
    #error not a supported configuration
#endif

    return 0;
}

static void
xpc_release_gru_mq_irq_uv(struct xpc_gru_mq_uv *mq)
{
#if defined CONFIG_X86_64
    uv_teardown_irq(mq->irq);

#elif defined CONFIG_IA64_GENERIC || defined CONFIG_IA64_SGI_UV
    int mmr_pnode;
    unsigned long mmr_value;

    mmr_pnode = uv_blade_to_pnode(mq->mmr_blade);
    mmr_value = 1UL << 16;

    uv_write_global_mmr64(mmr_pnode, mq->mmr_offset, mmr_value);
#else
    #error not a supported configuration
#endif
}

static int
xpc_gru_mq_watchlist_alloc_uv(struct xpc_gru_mq_uv *mq)
{
    int ret;

#if defined CONFIG_IA64_GENERIC || defined CONFIG_IA64_SGI_UV
    int mmr_pnode = uv_blade_to_pnode(mq->mmr_blade);

    ret = sn_mq_watchlist_alloc(mmr_pnode, (void *)uv_gpa(mq->address),
                    mq->order, &mq->mmr_offset);
    if (ret < 0) {
        dev_err(xpc_part, "sn_mq_watchlist_alloc() failed, ret=%d\n",
            ret);
        return -EBUSY;
    }
#elif defined CONFIG_X86_64
    ret = uv_bios_mq_watchlist_alloc(uv_gpa(mq->address),
                     mq->order, &mq->mmr_offset);
    if (ret < 0) {
        dev_err(xpc_part, "uv_bios_mq_watchlist_alloc() failed, "
            "ret=%d\n", ret);
        return ret;
    }
#else
    #error not a supported configuration
#endif

    mq->watchlist_num = ret;
    return 0;
}

static void
xpc_gru_mq_watchlist_free_uv(struct xpc_gru_mq_uv *mq)
{
    int ret;
    int mmr_pnode = uv_blade_to_pnode(mq->mmr_blade);

#if defined CONFIG_X86_64
    ret = uv_bios_mq_watchlist_free(mmr_pnode, mq->watchlist_num);
    BUG_ON(ret != BIOS_STATUS_SUCCESS);
#elif defined CONFIG_IA64_GENERIC || defined CONFIG_IA64_SGI_UV
    ret = sn_mq_watchlist_free(mmr_pnode, mq->watchlist_num);
    BUG_ON(ret != SALRET_OK);
#else
    #error not a supported configuration
#endif
}

static struct xpc_gru_mq_uv *
xpc_create_gru_mq_uv(unsigned int mq_size, int cpu, char *irq_name,
             irq_handler_t irq_handler)
{
    enum xp_retval xp_ret;
    int ret;
    int nid;
    int nasid;
    int pg_order;
    struct page *page;
    struct xpc_gru_mq_uv *mq;
    struct uv_IO_APIC_route_entry *mmr_value;

    mq = kmalloc(sizeof(struct xpc_gru_mq_uv), GFP_KERNEL);
    if (mq == NULL) {
        dev_err(xpc_part, "xpc_create_gru_mq_uv() failed to kmalloc() "
            "a xpc_gru_mq_uv structure\n");
        ret = -ENOMEM;
        goto out_0;
    }

    mq->gru_mq_desc = kzalloc(sizeof(struct gru_message_queue_desc),
                  GFP_KERNEL);
    if (mq->gru_mq_desc == NULL) {
        dev_err(xpc_part, "xpc_create_gru_mq_uv() failed to kmalloc() "
            "a gru_message_queue_desc structure\n");
        ret = -ENOMEM;
        goto out_1;
    }

    pg_order = get_order(mq_size);
    mq->order = pg_order + PAGE_SHIFT;
    mq_size = 1UL << mq->order;

    mq->mmr_blade = uv_cpu_to_blade_id(cpu);

    nid = cpu_to_node(cpu);
    page = alloc_pages_exact_node(nid,
                      GFP_KERNEL | __GFP_ZERO | GFP_THISNODE,
                      pg_order);
    if (page == NULL) {
        dev_err(xpc_part, "xpc_create_gru_mq_uv() failed to alloc %d "
            "bytes of memory on nid=%d for GRU mq\n", mq_size, nid);
        ret = -ENOMEM;
        goto out_2;
    }
    mq->address = page_address(page);

    /* enable generation of irq when GRU mq operation occurs to this mq */
    ret = xpc_gru_mq_watchlist_alloc_uv(mq);
    if (ret != 0)
        goto out_3;

    ret = xpc_get_gru_mq_irq_uv(mq, cpu, irq_name);
    if (ret != 0)
        goto out_4;

    ret = request_irq(mq->irq, irq_handler, 0, irq_name, NULL);
    if (ret != 0) {
        dev_err(xpc_part, "request_irq(irq=%d) returned error=%d\n",
            mq->irq, -ret);
        goto out_5;
    }

    nasid = UV_PNODE_TO_NASID(uv_cpu_to_pnode(cpu));

    mmr_value = (struct uv_IO_APIC_route_entry *)&mq->mmr_value;
    ret = gru_create_message_queue(mq->gru_mq_desc, mq->address, mq_size,
                     nasid, mmr_value->vector, mmr_value->dest);
    if (ret != 0) {
        dev_err(xpc_part, "gru_create_message_queue() returned "
            "error=%d\n", ret);
        ret = -EINVAL;
        goto out_6;
    }

    /* allow other partitions to access this GRU mq */
    xp_ret = xp_expand_memprotect(xp_pa(mq->address), mq_size);
    if (xp_ret != xpSuccess) {
        ret = -EACCES;
        goto out_6;
    }

    return mq;

    /* something went wrong */
out_6:
    free_irq(mq->irq, NULL);
out_5:
    xpc_release_gru_mq_irq_uv(mq);
out_4:
    xpc_gru_mq_watchlist_free_uv(mq);
out_3:
    free_pages((unsigned long)mq->address, pg_order);
out_2:
    kfree(mq->gru_mq_desc);
out_1:
    kfree(mq);
out_0:
    return ERR_PTR(ret);
}

static void
xpc_destroy_gru_mq_uv(struct xpc_gru_mq_uv *mq)
{
    unsigned int mq_size;
    int pg_order;
    int ret;

    /* disallow other partitions to access GRU mq */
    mq_size = 1UL << mq->order;
    ret = xp_restrict_memprotect(xp_pa(mq->address), mq_size);
    BUG_ON(ret != xpSuccess);

    /* unregister irq handler and release mq irq/vector mapping */
    free_irq(mq->irq, NULL);
    xpc_release_gru_mq_irq_uv(mq);

    /* disable generation of irq when GRU mq op occurs to this mq */
    xpc_gru_mq_watchlist_free_uv(mq);

    pg_order = mq->order - PAGE_SHIFT;
    free_pages((unsigned long)mq->address, pg_order);

    kfree(mq);
}

static enum xp_retval
xpc_send_gru_msg(struct gru_message_queue_desc *gru_mq_desc, void *msg,
         size_t msg_size)
{
    enum xp_retval xp_ret;
    int ret;

    while (1) {
        ret = gru_send_message_gpa(gru_mq_desc, msg, msg_size);
        if (ret == MQE_OK) {
            xp_ret = xpSuccess;
            break;
        }

        if (ret == MQE_QUEUE_FULL) {
            dev_dbg(xpc_chan, "gru_send_message_gpa() returned "
                "error=MQE_QUEUE_FULL\n");
            /* !!! handle QLimit reached; delay & try again */
            /* ??? Do we add a limit to the number of retries? */
            (void)msleep_interruptible(10);
        } else if (ret == MQE_CONGESTION) {
            dev_dbg(xpc_chan, "gru_send_message_gpa() returned "
                "error=MQE_CONGESTION\n");
            /* !!! handle LB Overflow; simply try again */
            /* ??? Do we add a limit to the number of retries? */
        } else {
            /* !!! Currently this is MQE_UNEXPECTED_CB_ERR */
            dev_err(xpc_chan, "gru_send_message_gpa() returned "
                "error=%d\n", ret);
            xp_ret = xpGruSendMqError;
            break;
        }
    }
    return xp_ret;
}

static void
xpc_process_activate_IRQ_rcvd_uv(void)
{
    unsigned long irq_flags;
    short partid;
    struct xpc_partition *part;
    u8 act_state_req;

    DBUG_ON(xpc_activate_IRQ_rcvd == 0);

    spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
    for (partid = 0; partid < XP_MAX_NPARTITIONS_UV; partid++) {
        part = &xpc_partitions[partid];

        if (part->sn.uv.act_state_req == 0)
            continue;

        xpc_activate_IRQ_rcvd--;
        BUG_ON(xpc_activate_IRQ_rcvd < 0);

        act_state_req = part->sn.uv.act_state_req;
        part->sn.uv.act_state_req = 0;
        spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);

        if (act_state_req == XPC_P_ASR_ACTIVATE_UV) {
            if (part->act_state == XPC_P_AS_INACTIVE)
                xpc_activate_partition(part);
            else if (part->act_state == XPC_P_AS_DEACTIVATING)
                XPC_DEACTIVATE_PARTITION(part, xpReactivating);

        } else if (act_state_req == XPC_P_ASR_REACTIVATE_UV) {
            if (part->act_state == XPC_P_AS_INACTIVE)
                xpc_activate_partition(part);
            else
                XPC_DEACTIVATE_PARTITION(part, xpReactivating);

        } else if (act_state_req == XPC_P_ASR_DEACTIVATE_UV) {
            XPC_DEACTIVATE_PARTITION(part, part->sn.uv.reason);

        } else {
            BUG();
        }

        spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
        if (xpc_activate_IRQ_rcvd == 0)
            break;
    }
    spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);

}

static void
xpc_handle_activate_mq_msg_uv(struct xpc_partition *part,
                  struct xpc_activate_mq_msghdr_uv *msg_hdr,
                  int part_setup,
                  int *wakeup_hb_checker)
{
    unsigned long irq_flags;
    struct xpc_partition_uv *part_uv = &part->sn.uv;
    struct xpc_openclose_args *args;

    part_uv->remote_act_state = msg_hdr->act_state;

    switch (msg_hdr->type) {
    case XPC_ACTIVATE_MQ_MSG_SYNC_ACT_STATE_UV:
        /* syncing of remote_act_state was just done above */
        break;

    case XPC_ACTIVATE_MQ_MSG_ACTIVATE_REQ_UV: {
        struct xpc_activate_mq_msg_activate_req_uv *msg;

        /*
         * ??? Do we deal here with ts_jiffies being different
         * ??? if act_state != XPC_P_AS_INACTIVE instead of
         * ??? below?
         */
        msg = container_of(msg_hdr, struct
                   xpc_activate_mq_msg_activate_req_uv, hdr);

        spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
        if (part_uv->act_state_req == 0)
            xpc_activate_IRQ_rcvd++;
        part_uv->act_state_req = XPC_P_ASR_ACTIVATE_UV;
        part->remote_rp_pa = msg->rp_gpa; /* !!! _pa is _gpa */
        part->remote_rp_ts_jiffies = msg_hdr->rp_ts_jiffies;
        part_uv->heartbeat_gpa = msg->heartbeat_gpa;

        if (msg->activate_gru_mq_desc_gpa !=
            part_uv->activate_gru_mq_desc_gpa) {
            spin_lock(&part_uv->flags_lock);
            part_uv->flags &= ~XPC_P_CACHED_ACTIVATE_GRU_MQ_DESC_UV;
            spin_unlock(&part_uv->flags_lock);
            part_uv->activate_gru_mq_desc_gpa =
                msg->activate_gru_mq_desc_gpa;
        }
        spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);

        (*wakeup_hb_checker)++;
        break;
    }
    case XPC_ACTIVATE_MQ_MSG_DEACTIVATE_REQ_UV: {
        struct xpc_activate_mq_msg_deactivate_req_uv *msg;

        msg = container_of(msg_hdr, struct
                   xpc_activate_mq_msg_deactivate_req_uv, hdr);

        spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
        if (part_uv->act_state_req == 0)
            xpc_activate_IRQ_rcvd++;
        part_uv->act_state_req = XPC_P_ASR_DEACTIVATE_UV;
        part_uv->reason = msg->reason;
        spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);

        (*wakeup_hb_checker)++;
        return;
    }
    case XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREQUEST_UV: {
        struct xpc_activate_mq_msg_chctl_closerequest_uv *msg;

        if (!part_setup)
            break;

        msg = container_of(msg_hdr, struct
                   xpc_activate_mq_msg_chctl_closerequest_uv,
                   hdr);
        args = &part->remote_openclose_args[msg->ch_number];
        args->reason = msg->reason;

        spin_lock_irqsave(&part->chctl_lock, irq_flags);
        part->chctl.flags[msg->ch_number] |= XPC_CHCTL_CLOSEREQUEST;
        spin_unlock_irqrestore(&part->chctl_lock, irq_flags);

        xpc_wakeup_channel_mgr(part);
        break;
    }
    case XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREPLY_UV: {
        struct xpc_activate_mq_msg_chctl_closereply_uv *msg;

        if (!part_setup)
            break;

        msg = container_of(msg_hdr, struct
                   xpc_activate_mq_msg_chctl_closereply_uv,
                   hdr);

        spin_lock_irqsave(&part->chctl_lock, irq_flags);
        part->chctl.flags[msg->ch_number] |= XPC_CHCTL_CLOSEREPLY;
        spin_unlock_irqrestore(&part->chctl_lock, irq_flags);

        xpc_wakeup_channel_mgr(part);
        break;
    }
    case XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREQUEST_UV: {
        struct xpc_activate_mq_msg_chctl_openrequest_uv *msg;

        if (!part_setup)
            break;

        msg = container_of(msg_hdr, struct
                   xpc_activate_mq_msg_chctl_openrequest_uv,
                   hdr);
        args = &part->remote_openclose_args[msg->ch_number];
        args->entry_size = msg->entry_size;
        args->local_nentries = msg->local_nentries;

        spin_lock_irqsave(&part->chctl_lock, irq_flags);
        part->chctl.flags[msg->ch_number] |= XPC_CHCTL_OPENREQUEST;
        spin_unlock_irqrestore(&part->chctl_lock, irq_flags);

        xpc_wakeup_channel_mgr(part);
        break;
    }
    case XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREPLY_UV: {
        struct xpc_activate_mq_msg_chctl_openreply_uv *msg;

        if (!part_setup)
            break;

        msg = container_of(msg_hdr, struct
                   xpc_activate_mq_msg_chctl_openreply_uv, hdr);
        args = &part->remote_openclose_args[msg->ch_number];
        args->remote_nentries = msg->remote_nentries;
        args->local_nentries = msg->local_nentries;
        args->local_msgqueue_pa = msg->notify_gru_mq_desc_gpa;

        spin_lock_irqsave(&part->chctl_lock, irq_flags);
        part->chctl.flags[msg->ch_number] |= XPC_CHCTL_OPENREPLY;
        spin_unlock_irqrestore(&part->chctl_lock, irq_flags);

        xpc_wakeup_channel_mgr(part);
        break;
    }
    case XPC_ACTIVATE_MQ_MSG_CHCTL_OPENCOMPLETE_UV: {
        struct xpc_activate_mq_msg_chctl_opencomplete_uv *msg;

        if (!part_setup)
            break;

        msg = container_of(msg_hdr, struct
                xpc_activate_mq_msg_chctl_opencomplete_uv, hdr);
        spin_lock_irqsave(&part->chctl_lock, irq_flags);
        part->chctl.flags[msg->ch_number] |= XPC_CHCTL_OPENCOMPLETE;
        spin_unlock_irqrestore(&part->chctl_lock, irq_flags);

        xpc_wakeup_channel_mgr(part);
    }
    case XPC_ACTIVATE_MQ_MSG_MARK_ENGAGED_UV:
        spin_lock_irqsave(&part_uv->flags_lock, irq_flags);
        part_uv->flags |= XPC_P_ENGAGED_UV;
        spin_unlock_irqrestore(&part_uv->flags_lock, irq_flags);
        break;

    case XPC_ACTIVATE_MQ_MSG_MARK_DISENGAGED_UV:
        spin_lock_irqsave(&part_uv->flags_lock, irq_flags);
        part_uv->flags &= ~XPC_P_ENGAGED_UV;
        spin_unlock_irqrestore(&part_uv->flags_lock, irq_flags);
        break;

    default:
        dev_err(xpc_part, "received unknown activate_mq msg type=%d "
            "from partition=%d\n", msg_hdr->type, XPC_PARTID(part));

        /* get hb checker to deactivate from the remote partition */
        spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
        if (part_uv->act_state_req == 0)
            xpc_activate_IRQ_rcvd++;
        part_uv->act_state_req = XPC_P_ASR_DEACTIVATE_UV;
        part_uv->reason = xpBadMsgType;
        spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);

        (*wakeup_hb_checker)++;
        return;
    }

    if (msg_hdr->rp_ts_jiffies != part->remote_rp_ts_jiffies &&
        part->remote_rp_ts_jiffies != 0) {
        /*
         * ??? Does what we do here need to be sensitive to
         * ??? act_state or remote_act_state?
         */
        spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
        if (part_uv->act_state_req == 0)
            xpc_activate_IRQ_rcvd++;
        part_uv->act_state_req = XPC_P_ASR_REACTIVATE_UV;
        spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);

        (*wakeup_hb_checker)++;
    }
}

static irqreturn_t
xpc_handle_activate_IRQ_uv(int irq, void *dev_id)
{
    struct xpc_activate_mq_msghdr_uv *msg_hdr;
    short partid;
    struct xpc_partition *part;
    int wakeup_hb_checker = 0;
    int part_referenced;

    while (1) {
        msg_hdr = gru_get_next_message(xpc_activate_mq_uv->gru_mq_desc);
        if (msg_hdr == NULL)
            break;

        partid = msg_hdr->partid;
        if (partid < 0 || partid >= XP_MAX_NPARTITIONS_UV) {
            dev_err(xpc_part, "xpc_handle_activate_IRQ_uv() "
                "received invalid partid=0x%x in message\n",
                partid);
        } else {
            part = &xpc_partitions[partid];

            part_referenced = xpc_part_ref(part);
            xpc_handle_activate_mq_msg_uv(part, msg_hdr,
                              part_referenced,
                              &wakeup_hb_checker);
            if (part_referenced)
                xpc_part_deref(part);
        }

        gru_free_message(xpc_activate_mq_uv->gru_mq_desc, msg_hdr);
    }

    if (wakeup_hb_checker)
        wake_up_interruptible(&xpc_activate_IRQ_wq);

    return IRQ_HANDLED;
}

static enum xp_retval
xpc_cache_remote_gru_mq_desc_uv(struct gru_message_queue_desc *gru_mq_desc,
                unsigned long gru_mq_desc_gpa)
{
    enum xp_retval ret;

    ret = xp_remote_memcpy(uv_gpa(gru_mq_desc), gru_mq_desc_gpa,
                   sizeof(struct gru_message_queue_desc));
    if (ret == xpSuccess)
        gru_mq_desc->mq = NULL;

    return ret;
}

static enum xp_retval
xpc_send_activate_IRQ_uv(struct xpc_partition *part, void *msg, size_t msg_size,
             int msg_type)
{
    struct xpc_activate_mq_msghdr_uv *msg_hdr = msg;
    struct xpc_partition_uv *part_uv = &part->sn.uv;
    struct gru_message_queue_desc *gru_mq_desc;
    unsigned long irq_flags;
    enum xp_retval ret;

    DBUG_ON(msg_size > XPC_ACTIVATE_MSG_SIZE_UV);

    msg_hdr->type = msg_type;
    msg_hdr->partid = xp_partition_id;
    msg_hdr->act_state = part->act_state;
    msg_hdr->rp_ts_jiffies = xpc_rsvd_page->ts_jiffies;

    mutex_lock(&part_uv->cached_activate_gru_mq_desc_mutex);
again:
    if (!(part_uv->flags & XPC_P_CACHED_ACTIVATE_GRU_MQ_DESC_UV)) {
        gru_mq_desc = part_uv->cached_activate_gru_mq_desc;
        if (gru_mq_desc == NULL) {
            gru_mq_desc = kmalloc(sizeof(struct
                          gru_message_queue_desc),
                          GFP_KERNEL);
            if (gru_mq_desc == NULL) {
                ret = xpNoMemory;
                goto done;
            }
            part_uv->cached_activate_gru_mq_desc = gru_mq_desc;
        }

        ret = xpc_cache_remote_gru_mq_desc_uv(gru_mq_desc,
                              part_uv->
                              activate_gru_mq_desc_gpa);
        if (ret != xpSuccess)
            goto done;

        spin_lock_irqsave(&part_uv->flags_lock, irq_flags);
        part_uv->flags |= XPC_P_CACHED_ACTIVATE_GRU_MQ_DESC_UV;
        spin_unlock_irqrestore(&part_uv->flags_lock, irq_flags);
    }

    /* ??? Is holding a spin_lock (ch->lock) during this call a bad idea? */
    ret = xpc_send_gru_msg(part_uv->cached_activate_gru_mq_desc, msg,
                   msg_size);
    if (ret != xpSuccess) {
        smp_rmb();  /* ensure a fresh copy of part_uv->flags */
        if (!(part_uv->flags & XPC_P_CACHED_ACTIVATE_GRU_MQ_DESC_UV))
            goto again;
    }
done:
    mutex_unlock(&part_uv->cached_activate_gru_mq_desc_mutex);
    return ret;
}

static void
xpc_send_activate_IRQ_part_uv(struct xpc_partition *part, void *msg,
                  size_t msg_size, int msg_type)
{
    enum xp_retval ret;

    ret = xpc_send_activate_IRQ_uv(part, msg, msg_size, msg_type);
    if (unlikely(ret != xpSuccess))
        XPC_DEACTIVATE_PARTITION(part, ret);
}

static void
xpc_send_activate_IRQ_ch_uv(struct xpc_channel *ch, unsigned long *irq_flags,
             void *msg, size_t msg_size, int msg_type)
{
    struct xpc_partition *part = &xpc_partitions[ch->partid];
    enum xp_retval ret;

    ret = xpc_send_activate_IRQ_uv(part, msg, msg_size, msg_type);
    if (unlikely(ret != xpSuccess)) {
        if (irq_flags != NULL)
            spin_unlock_irqrestore(&ch->lock, *irq_flags);

        XPC_DEACTIVATE_PARTITION(part, ret);

        if (irq_flags != NULL)
            spin_lock_irqsave(&ch->lock, *irq_flags);
    }
}

static void
xpc_send_local_activate_IRQ_uv(struct xpc_partition *part, int act_state_req)
{
    unsigned long irq_flags;
    struct xpc_partition_uv *part_uv = &part->sn.uv;

    /*
     * !!! Make our side think that the remote partition sent an activate
     * !!! mq message our way by doing what the activate IRQ handler would
     * !!! do had one really been sent.
     */

    spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
    if (part_uv->act_state_req == 0)
        xpc_activate_IRQ_rcvd++;
    part_uv->act_state_req = act_state_req;
    spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);

    wake_up_interruptible(&xpc_activate_IRQ_wq);
}

static enum xp_retval
xpc_get_partition_rsvd_page_pa_uv(void *buf, u64 *cookie, unsigned long *rp_pa,
                  size_t *len)
{
    s64 status;
    enum xp_retval ret;

#if defined CONFIG_X86_64
    status = uv_bios_reserved_page_pa((u64)buf, cookie, (u64 *)rp_pa,
                      (u64 *)len);
    if (status == BIOS_STATUS_SUCCESS)
        ret = xpSuccess;
    else if (status == BIOS_STATUS_MORE_PASSES)
        ret = xpNeedMoreInfo;
    else
        ret = xpBiosError;

#elif defined CONFIG_IA64_GENERIC || defined CONFIG_IA64_SGI_UV
    status = sn_partition_reserved_page_pa((u64)buf, cookie, rp_pa, len);
    if (status == SALRET_OK)
        ret = xpSuccess;
    else if (status == SALRET_MORE_PASSES)
        ret = xpNeedMoreInfo;
    else
        ret = xpSalError;

#else
    #error not a supported configuration
#endif

    return ret;
}

static int
xpc_setup_rsvd_page_uv(struct xpc_rsvd_page *rp)
{
    xpc_heartbeat_uv =
        &xpc_partitions[sn_partition_id].sn.uv.cached_heartbeat;
    rp->sn.uv.heartbeat_gpa = uv_gpa(xpc_heartbeat_uv);
    rp->sn.uv.activate_gru_mq_desc_gpa =
        uv_gpa(xpc_activate_mq_uv->gru_mq_desc);
    return 0;
}

static void
xpc_allow_hb_uv(short partid)
{
}

static void
xpc_disallow_hb_uv(short partid)
{
}

static void
xpc_disallow_all_hbs_uv(void)
{
}

static void
xpc_increment_heartbeat_uv(void)
{
    xpc_heartbeat_uv->value++;
}

static void
xpc_offline_heartbeat_uv(void)
{
    xpc_increment_heartbeat_uv();
    xpc_heartbeat_uv->offline = 1;
}

static void
xpc_online_heartbeat_uv(void)
{
    xpc_increment_heartbeat_uv();
    xpc_heartbeat_uv->offline = 0;
}

static void
xpc_heartbeat_init_uv(void)
{
    xpc_heartbeat_uv->value = 1;
    xpc_heartbeat_uv->offline = 0;
}

static void
xpc_heartbeat_exit_uv(void)
{
    xpc_offline_heartbeat_uv();
}

static enum xp_retval
xpc_get_remote_heartbeat_uv(struct xpc_partition *part)
{
    struct xpc_partition_uv *part_uv = &part->sn.uv;
    enum xp_retval ret;

    ret = xp_remote_memcpy(uv_gpa(&part_uv->cached_heartbeat),
                   part_uv->heartbeat_gpa,
                   sizeof(struct xpc_heartbeat_uv));
    if (ret != xpSuccess)
        return ret;

    if (part_uv->cached_heartbeat.value == part->last_heartbeat &&
        !part_uv->cached_heartbeat.offline) {

        ret = xpNoHeartbeat;
    } else {
        part->last_heartbeat = part_uv->cached_heartbeat.value;
    }
    return ret;
}

static void
xpc_request_partition_activation_uv(struct xpc_rsvd_page *remote_rp,
                    unsigned long remote_rp_gpa, int nasid)
{
    short partid = remote_rp->SAL_partid;
    struct xpc_partition *part = &xpc_partitions[partid];
    struct xpc_activate_mq_msg_activate_req_uv msg;

    part->remote_rp_pa = remote_rp_gpa; /* !!! _pa here is really _gpa */
    part->remote_rp_ts_jiffies = remote_rp->ts_jiffies;
    part->sn.uv.heartbeat_gpa = remote_rp->sn.uv.heartbeat_gpa;
    part->sn.uv.activate_gru_mq_desc_gpa =
        remote_rp->sn.uv.activate_gru_mq_desc_gpa;

    /*
     * ??? Is it a good idea to make this conditional on what is
     * ??? potentially stale state information?
     */
    if (part->sn.uv.remote_act_state == XPC_P_AS_INACTIVE) {
        msg.rp_gpa = uv_gpa(xpc_rsvd_page);
        msg.heartbeat_gpa = xpc_rsvd_page->sn.uv.heartbeat_gpa;
        msg.activate_gru_mq_desc_gpa =
            xpc_rsvd_page->sn.uv.activate_gru_mq_desc_gpa;
        xpc_send_activate_IRQ_part_uv(part, &msg, sizeof(msg),
                       XPC_ACTIVATE_MQ_MSG_ACTIVATE_REQ_UV);
    }

    if (part->act_state == XPC_P_AS_INACTIVE)
        xpc_send_local_activate_IRQ_uv(part, XPC_P_ASR_ACTIVATE_UV);
}

static void
xpc_request_partition_reactivation_uv(struct xpc_partition *part)
{
    xpc_send_local_activate_IRQ_uv(part, XPC_P_ASR_ACTIVATE_UV);
}

static void
xpc_request_partition_deactivation_uv(struct xpc_partition *part)
{
    struct xpc_activate_mq_msg_deactivate_req_uv msg;

    /*
     * ??? Is it a good idea to make this conditional on what is
     * ??? potentially stale state information?
     */
    if (part->sn.uv.remote_act_state != XPC_P_AS_DEACTIVATING &&
        part->sn.uv.remote_act_state != XPC_P_AS_INACTIVE) {

        msg.reason = part->reason;
        xpc_send_activate_IRQ_part_uv(part, &msg, sizeof(msg),
                     XPC_ACTIVATE_MQ_MSG_DEACTIVATE_REQ_UV);
    }
}

static void
xpc_cancel_partition_deactivation_request_uv(struct xpc_partition *part)
{
    /* nothing needs to be done */
    return;
}

static void
xpc_init_fifo_uv(struct xpc_fifo_head_uv *head)
{
    head->first = NULL;
    head->last = NULL;
    spin_lock_init(&head->lock);
    head->n_entries = 0;
}

static void *
xpc_get_fifo_entry_uv(struct xpc_fifo_head_uv *head)
{
    unsigned long irq_flags;
    struct xpc_fifo_entry_uv *first;

    spin_lock_irqsave(&head->lock, irq_flags);
    first = head->first;
    if (head->first != NULL) {
        head->first = first->next;
        if (head->first == NULL)
            head->last = NULL;

        head->n_entries--;
        BUG_ON(head->n_entries < 0);

        first->next = NULL;
    }
    spin_unlock_irqrestore(&head->lock, irq_flags);
    return first;
}

static void
xpc_put_fifo_entry_uv(struct xpc_fifo_head_uv *head,
              struct xpc_fifo_entry_uv *last)
{
    unsigned long irq_flags;

    last->next = NULL;
    spin_lock_irqsave(&head->lock, irq_flags);
    if (head->last != NULL)
        head->last->next = last;
    else
        head->first = last;
    head->last = last;
    head->n_entries++;
    spin_unlock_irqrestore(&head->lock, irq_flags);
}

static int
xpc_n_of_fifo_entries_uv(struct xpc_fifo_head_uv *head)
{
    return head->n_entries;
}

/*
 * Setup the channel structures that are uv specific.
 */
static enum xp_retval
xpc_setup_ch_structures_uv(struct xpc_partition *part)
{
    struct xpc_channel_uv *ch_uv;
    int ch_number;

    for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
        ch_uv = &part->channels[ch_number].sn.uv;

        xpc_init_fifo_uv(&ch_uv->msg_slot_free_list);
        xpc_init_fifo_uv(&ch_uv->recv_msg_list);
    }

    return xpSuccess;
}

/*
 * Teardown the channel structures that are uv specific.
 */
static void
xpc_teardown_ch_structures_uv(struct xpc_partition *part)
{
    /* nothing needs to be done */
    return;
}

static enum xp_retval
xpc_make_first_contact_uv(struct xpc_partition *part)
{
    struct xpc_activate_mq_msg_uv msg;

    /*
     * We send a sync msg to get the remote partition's remote_act_state
     * updated to our current act_state which at this point should
     * be XPC_P_AS_ACTIVATING.
     */
    xpc_send_activate_IRQ_part_uv(part, &msg, sizeof(msg),
                      XPC_ACTIVATE_MQ_MSG_SYNC_ACT_STATE_UV);

    while (!((part->sn.uv.remote_act_state == XPC_P_AS_ACTIVATING) ||
         (part->sn.uv.remote_act_state == XPC_P_AS_ACTIVE))) {

        dev_dbg(xpc_part, "waiting to make first contact with "
            "partition %d\n", XPC_PARTID(part));

        /* wait a 1/4 of a second or so */
        (void)msleep_interruptible(250);

        if (part->act_state == XPC_P_AS_DEACTIVATING)
            return part->reason;
    }

    return xpSuccess;
}

static u64
xpc_get_chctl_all_flags_uv(struct xpc_partition *part)
{
    unsigned long irq_flags;
    union xpc_channel_ctl_flags chctl;

    spin_lock_irqsave(&part->chctl_lock, irq_flags);
    chctl = part->chctl;
    if (chctl.all_flags != 0)
        part->chctl.all_flags = 0;

    spin_unlock_irqrestore(&part->chctl_lock, irq_flags);
    return chctl.all_flags;
}

static enum xp_retval
xpc_allocate_send_msg_slot_uv(struct xpc_channel *ch)
{
    struct xpc_channel_uv *ch_uv = &ch->sn.uv;
    struct xpc_send_msg_slot_uv *msg_slot;
    unsigned long irq_flags;
    int nentries;
    int entry;
    size_t nbytes;

    for (nentries = ch->local_nentries; nentries > 0; nentries--) {
        nbytes = nentries * sizeof(struct xpc_send_msg_slot_uv);
        ch_uv->send_msg_slots = kzalloc(nbytes, GFP_KERNEL);
        if (ch_uv->send_msg_slots == NULL)
            continue;

        for (entry = 0; entry < nentries; entry++) {
            msg_slot = &ch_uv->send_msg_slots[entry];

            msg_slot->msg_slot_number = entry;
            xpc_put_fifo_entry_uv(&ch_uv->msg_slot_free_list,
                          &msg_slot->next);
        }

        spin_lock_irqsave(&ch->lock, irq_flags);
        if (nentries < ch->local_nentries)
            ch->local_nentries = nentries;
        spin_unlock_irqrestore(&ch->lock, irq_flags);
        return xpSuccess;
    }

    return xpNoMemory;
}

static enum xp_retval
xpc_allocate_recv_msg_slot_uv(struct xpc_channel *ch)
{
    struct xpc_channel_uv *ch_uv = &ch->sn.uv;
    struct xpc_notify_mq_msg_uv *msg_slot;
    unsigned long irq_flags;
    int nentries;
    int entry;
    size_t nbytes;

    for (nentries = ch->remote_nentries; nentries > 0; nentries--) {
        nbytes = nentries * ch->entry_size;
        ch_uv->recv_msg_slots = kzalloc(nbytes, GFP_KERNEL);
        if (ch_uv->recv_msg_slots == NULL)
            continue;

        for (entry = 0; entry < nentries; entry++) {
            msg_slot = ch_uv->recv_msg_slots +
                entry * ch->entry_size;

            msg_slot->hdr.msg_slot_number = entry;
        }

        spin_lock_irqsave(&ch->lock, irq_flags);
        if (nentries < ch->remote_nentries)
            ch->remote_nentries = nentries;
        spin_unlock_irqrestore(&ch->lock, irq_flags);
        return xpSuccess;
    }

    return xpNoMemory;
}

/*
 * Allocate msg_slots associated with the channel.
 */
static enum xp_retval
xpc_setup_msg_structures_uv(struct xpc_channel *ch)
{
    static enum xp_retval ret;
    struct xpc_channel_uv *ch_uv = &ch->sn.uv;

    DBUG_ON(ch->flags & XPC_C_SETUP);

    ch_uv->cached_notify_gru_mq_desc = kmalloc(sizeof(struct
                           gru_message_queue_desc),
                           GFP_KERNEL);
    if (ch_uv->cached_notify_gru_mq_desc == NULL)
        return xpNoMemory;

    ret = xpc_allocate_send_msg_slot_uv(ch);
    if (ret == xpSuccess) {

        ret = xpc_allocate_recv_msg_slot_uv(ch);
        if (ret != xpSuccess) {
            kfree(ch_uv->send_msg_slots);
            xpc_init_fifo_uv(&ch_uv->msg_slot_free_list);
        }
    }
    return ret;
}

/*
 * Free up msg_slots and clear other stuff that were setup for the specified
 * channel.
 */
static void
xpc_teardown_msg_structures_uv(struct xpc_channel *ch)
{
    struct xpc_channel_uv *ch_uv = &ch->sn.uv;

    DBUG_ON(!spin_is_locked(&ch->lock));

    kfree(ch_uv->cached_notify_gru_mq_desc);
    ch_uv->cached_notify_gru_mq_desc = NULL;

    if (ch->flags & XPC_C_SETUP) {
        xpc_init_fifo_uv(&ch_uv->msg_slot_free_list);
        kfree(ch_uv->send_msg_slots);
        xpc_init_fifo_uv(&ch_uv->recv_msg_list);
        kfree(ch_uv->recv_msg_slots);
    }
}

static void
xpc_send_chctl_closerequest_uv(struct xpc_channel *ch, unsigned long *irq_flags)
{
    struct xpc_activate_mq_msg_chctl_closerequest_uv msg;

    msg.ch_number = ch->number;
    msg.reason = ch->reason;
    xpc_send_activate_IRQ_ch_uv(ch, irq_flags, &msg, sizeof(msg),
                    XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREQUEST_UV);
}

static void
xpc_send_chctl_closereply_uv(struct xpc_channel *ch, unsigned long *irq_flags)
{
    struct xpc_activate_mq_msg_chctl_closereply_uv msg;

    msg.ch_number = ch->number;
    xpc_send_activate_IRQ_ch_uv(ch, irq_flags, &msg, sizeof(msg),
                    XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREPLY_UV);
}

static void
xpc_send_chctl_openrequest_uv(struct xpc_channel *ch, unsigned long *irq_flags)
{
    struct xpc_activate_mq_msg_chctl_openrequest_uv msg;

    msg.ch_number = ch->number;
    msg.entry_size = ch->entry_size;
    msg.local_nentries = ch->local_nentries;
    xpc_send_activate_IRQ_ch_uv(ch, irq_flags, &msg, sizeof(msg),
                    XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREQUEST_UV);
}

static void
xpc_send_chctl_openreply_uv(struct xpc_channel *ch, unsigned long *irq_flags)
{
    struct xpc_activate_mq_msg_chctl_openreply_uv msg;

    msg.ch_number = ch->number;
    msg.local_nentries = ch->local_nentries;
    msg.remote_nentries = ch->remote_nentries;
    msg.notify_gru_mq_desc_gpa = uv_gpa(xpc_notify_mq_uv->gru_mq_desc);
    xpc_send_activate_IRQ_ch_uv(ch, irq_flags, &msg, sizeof(msg),
                    XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREPLY_UV);
}

static void
xpc_send_chctl_opencomplete_uv(struct xpc_channel *ch, unsigned long *irq_flags)
{
    struct xpc_activate_mq_msg_chctl_opencomplete_uv msg;

    msg.ch_number = ch->number;
    xpc_send_activate_IRQ_ch_uv(ch, irq_flags, &msg, sizeof(msg),
                    XPC_ACTIVATE_MQ_MSG_CHCTL_OPENCOMPLETE_UV);
}

static void
xpc_send_chctl_local_msgrequest_uv(struct xpc_partition *part, int ch_number)
{
    unsigned long irq_flags;

    spin_lock_irqsave(&part->chctl_lock, irq_flags);
    part->chctl.flags[ch_number] |= XPC_CHCTL_MSGREQUEST;
    spin_unlock_irqrestore(&part->chctl_lock, irq_flags);

    xpc_wakeup_channel_mgr(part);
}

static enum xp_retval
xpc_save_remote_msgqueue_pa_uv(struct xpc_channel *ch,
                   unsigned long gru_mq_desc_gpa)
{
    struct xpc_channel_uv *ch_uv = &ch->sn.uv;

    DBUG_ON(ch_uv->cached_notify_gru_mq_desc == NULL);
    return xpc_cache_remote_gru_mq_desc_uv(ch_uv->cached_notify_gru_mq_desc,
                           gru_mq_desc_gpa);
}

static void
xpc_indicate_partition_engaged_uv(struct xpc_partition *part)
{
    struct xpc_activate_mq_msg_uv msg;

    xpc_send_activate_IRQ_part_uv(part, &msg, sizeof(msg),
                      XPC_ACTIVATE_MQ_MSG_MARK_ENGAGED_UV);
}

static void
xpc_indicate_partition_disengaged_uv(struct xpc_partition *part)
{
    struct xpc_activate_mq_msg_uv msg;

    xpc_send_activate_IRQ_part_uv(part, &msg, sizeof(msg),
                      XPC_ACTIVATE_MQ_MSG_MARK_DISENGAGED_UV);
}

static void
xpc_assume_partition_disengaged_uv(short partid)
{
    struct xpc_partition_uv *part_uv = &xpc_partitions[partid].sn.uv;
    unsigned long irq_flags;

    spin_lock_irqsave(&part_uv->flags_lock, irq_flags);
    part_uv->flags &= ~XPC_P_ENGAGED_UV;
    spin_unlock_irqrestore(&part_uv->flags_lock, irq_flags);
}

static int
xpc_partition_engaged_uv(short partid)
{
    return (xpc_partitions[partid].sn.uv.flags & XPC_P_ENGAGED_UV) != 0;
}

static int
xpc_any_partition_engaged_uv(void)
{
    struct xpc_partition_uv *part_uv;
    short partid;

    for (partid = 0; partid < XP_MAX_NPARTITIONS_UV; partid++) {
        part_uv = &xpc_partitions[partid].sn.uv;
        if ((part_uv->flags & XPC_P_ENGAGED_UV) != 0)
            return 1;
    }
    return 0;
}

static enum xp_retval
xpc_allocate_msg_slot_uv(struct xpc_channel *ch, u32 flags,
             struct xpc_send_msg_slot_uv **address_of_msg_slot)
{
    enum xp_retval ret;
    struct xpc_send_msg_slot_uv *msg_slot;
    struct xpc_fifo_entry_uv *entry;

    while (1) {
        entry = xpc_get_fifo_entry_uv(&ch->sn.uv.msg_slot_free_list);
        if (entry != NULL)
            break;

        if (flags & XPC_NOWAIT)
            return xpNoWait;

        ret = xpc_allocate_msg_wait(ch);
        if (ret != xpInterrupted && ret != xpTimeout)
            return ret;
    }

    msg_slot = container_of(entry, struct xpc_send_msg_slot_uv, next);
    *address_of_msg_slot = msg_slot;
    return xpSuccess;
}

static void
xpc_free_msg_slot_uv(struct xpc_channel *ch,
             struct xpc_send_msg_slot_uv *msg_slot)
{
    xpc_put_fifo_entry_uv(&ch->sn.uv.msg_slot_free_list, &msg_slot->next);

    /* wakeup anyone waiting for a free msg slot */
    if (atomic_read(&ch->n_on_msg_allocate_wq) > 0)
        wake_up(&ch->msg_allocate_wq);
}

static void
xpc_notify_sender_uv(struct xpc_channel *ch,
             struct xpc_send_msg_slot_uv *msg_slot,
             enum xp_retval reason)
{
    xpc_notify_func func = msg_slot->func;

    if (func != NULL && cmpxchg(&msg_slot->func, func, NULL) == func) {

        atomic_dec(&ch->n_to_notify);

        dev_dbg(xpc_chan, "msg_slot->func() called, msg_slot=0x%p "
            "msg_slot_number=%d partid=%d channel=%d\n", msg_slot,
            msg_slot->msg_slot_number, ch->partid, ch->number);

        func(reason, ch->partid, ch->number, msg_slot->key);

        dev_dbg(xpc_chan, "msg_slot->func() returned, msg_slot=0x%p "
            "msg_slot_number=%d partid=%d channel=%d\n", msg_slot,
            msg_slot->msg_slot_number, ch->partid, ch->number);
    }
}

static void
xpc_handle_notify_mq_ack_uv(struct xpc_channel *ch,
                struct xpc_notify_mq_msg_uv *msg)
{
    struct xpc_send_msg_slot_uv *msg_slot;
    int entry = msg->hdr.msg_slot_number % ch->local_nentries;

    msg_slot = &ch->sn.uv.send_msg_slots[entry];

    BUG_ON(msg_slot->msg_slot_number != msg->hdr.msg_slot_number);
    msg_slot->msg_slot_number += ch->local_nentries;

    if (msg_slot->func != NULL)
        xpc_notify_sender_uv(ch, msg_slot, xpMsgDelivered);

    xpc_free_msg_slot_uv(ch, msg_slot);
}

static void
xpc_handle_notify_mq_msg_uv(struct xpc_partition *part,
                struct xpc_notify_mq_msg_uv *msg)
{
    struct xpc_partition_uv *part_uv = &part->sn.uv;
    struct xpc_channel *ch;
    struct xpc_channel_uv *ch_uv;
    struct xpc_notify_mq_msg_uv *msg_slot;
    unsigned long irq_flags;
    int ch_number = msg->hdr.ch_number;

    if (unlikely(ch_number >= part->nchannels)) {
        dev_err(xpc_part, "xpc_handle_notify_IRQ_uv() received invalid "
            "channel number=0x%x in message from partid=%d\n",
            ch_number, XPC_PARTID(part));

        /* get hb checker to deactivate from the remote partition */
        spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
        if (part_uv->act_state_req == 0)
            xpc_activate_IRQ_rcvd++;
        part_uv->act_state_req = XPC_P_ASR_DEACTIVATE_UV;
        part_uv->reason = xpBadChannelNumber;
        spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);

        wake_up_interruptible(&xpc_activate_IRQ_wq);
        return;
    }

    ch = &part->channels[ch_number];
    xpc_msgqueue_ref(ch);

    if (!(ch->flags & XPC_C_CONNECTED)) {
        xpc_msgqueue_deref(ch);
        return;
    }

    /* see if we're really dealing with an ACK for a previously sent msg */
    if (msg->hdr.size == 0) {
        xpc_handle_notify_mq_ack_uv(ch, msg);
        xpc_msgqueue_deref(ch);
        return;
    }

    /* we're dealing with a normal message sent via the notify_mq */
    ch_uv = &ch->sn.uv;

    msg_slot = ch_uv->recv_msg_slots +
        (msg->hdr.msg_slot_number % ch->remote_nentries) * ch->entry_size;

    BUG_ON(msg_slot->hdr.size != 0);

    memcpy(msg_slot, msg, msg->hdr.size);

    xpc_put_fifo_entry_uv(&ch_uv->recv_msg_list, &msg_slot->hdr.u.next);

    if (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) {
        /*
         * If there is an existing idle kthread get it to deliver
         * the payload, otherwise we'll have to get the channel mgr
         * for this partition to create a kthread to do the delivery.
         */
        if (atomic_read(&ch->kthreads_idle) > 0)
            wake_up_nr(&ch->idle_wq, 1);
        else
            xpc_send_chctl_local_msgrequest_uv(part, ch->number);
    }
    xpc_msgqueue_deref(ch);
}

static irqreturn_t
xpc_handle_notify_IRQ_uv(int irq, void *dev_id)
{
    struct xpc_notify_mq_msg_uv *msg;
    short partid;
    struct xpc_partition *part;

    while ((msg = gru_get_next_message(xpc_notify_mq_uv->gru_mq_desc)) !=
           NULL) {

        partid = msg->hdr.partid;
        if (partid < 0 || partid >= XP_MAX_NPARTITIONS_UV) {
            dev_err(xpc_part, "xpc_handle_notify_IRQ_uv() received "
                "invalid partid=0x%x in message\n", partid);
        } else {
            part = &xpc_partitions[partid];

            if (xpc_part_ref(part)) {
                xpc_handle_notify_mq_msg_uv(part, msg);
                xpc_part_deref(part);
            }
        }

        gru_free_message(xpc_notify_mq_uv->gru_mq_desc, msg);
    }

    return IRQ_HANDLED;
}

static int
xpc_n_of_deliverable_payloads_uv(struct xpc_channel *ch)
{
    return xpc_n_of_fifo_entries_uv(&ch->sn.uv.recv_msg_list);
}

static void
xpc_process_msg_chctl_flags_uv(struct xpc_partition *part, int ch_number)
{
    struct xpc_channel *ch = &part->channels[ch_number];
    int ndeliverable_payloads;

    xpc_msgqueue_ref(ch);

    ndeliverable_payloads = xpc_n_of_deliverable_payloads_uv(ch);

    if (ndeliverable_payloads > 0 &&
        (ch->flags & XPC_C_CONNECTED) &&
        (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE)) {

        xpc_activate_kthreads(ch, ndeliverable_payloads);
    }

    xpc_msgqueue_deref(ch);
}

static enum xp_retval
xpc_send_payload_uv(struct xpc_channel *ch, u32 flags, void *payload,
            u16 payload_size, u8 notify_type, xpc_notify_func func,
            void *key)
{
    enum xp_retval ret = xpSuccess;
    struct xpc_send_msg_slot_uv *msg_slot = NULL;
    struct xpc_notify_mq_msg_uv *msg;
    u8 msg_buffer[XPC_NOTIFY_MSG_SIZE_UV];
    size_t msg_size;

    DBUG_ON(notify_type != XPC_N_CALL);

    msg_size = sizeof(struct xpc_notify_mq_msghdr_uv) + payload_size;
    if (msg_size > ch->entry_size)
        return xpPayloadTooBig;

    xpc_msgqueue_ref(ch);

    if (ch->flags & XPC_C_DISCONNECTING) {
        ret = ch->reason;
        goto out_1;
    }
    if (!(ch->flags & XPC_C_CONNECTED)) {
        ret = xpNotConnected;
        goto out_1;
    }

    ret = xpc_allocate_msg_slot_uv(ch, flags, &msg_slot);
    if (ret != xpSuccess)
        goto out_1;

    if (func != NULL) {
        atomic_inc(&ch->n_to_notify);

        msg_slot->key = key;
        smp_wmb(); /* a non-NULL func must hit memory after the key */
        msg_slot->func = func;

        if (ch->flags & XPC_C_DISCONNECTING) {
            ret = ch->reason;
            goto out_2;
        }
    }

    msg = (struct xpc_notify_mq_msg_uv *)&msg_buffer;
    msg->hdr.partid = xp_partition_id;
    msg->hdr.ch_number = ch->number;
    msg->hdr.size = msg_size;
    msg->hdr.msg_slot_number = msg_slot->msg_slot_number;
    memcpy(&msg->payload, payload, payload_size);

    ret = xpc_send_gru_msg(ch->sn.uv.cached_notify_gru_mq_desc, msg,
                   msg_size);
    if (ret == xpSuccess)
        goto out_1;

    XPC_DEACTIVATE_PARTITION(&xpc_partitions[ch->partid], ret);
out_2:
    if (func != NULL) {
        /*
         * Try to NULL the msg_slot's func field. If we fail, then
         * xpc_notify_senders_of_disconnect_uv() beat us to it, in which
         * case we need to pretend we succeeded to send the message
         * since the user will get a callout for the disconnect error
         * by xpc_notify_senders_of_disconnect_uv(), and to also get an
         * error returned here will confuse them. Additionally, since
         * in this case the channel is being disconnected we don't need
         * to put the the msg_slot back on the free list.
         */
        if (cmpxchg(&msg_slot->func, func, NULL) != func) {
            ret = xpSuccess;
            goto out_1;
        }

        msg_slot->key = NULL;
        atomic_dec(&ch->n_to_notify);
    }
    xpc_free_msg_slot_uv(ch, msg_slot);
out_1:
    xpc_msgqueue_deref(ch);
    return ret;
}

/*
 * Tell the callers of xpc_send_notify() that the status of their payloads
 * is unknown because the channel is now disconnecting.
 *
 * We don't worry about putting these msg_slots on the free list since the
 * msg_slots themselves are about to be kfree'd.
 */
static void
xpc_notify_senders_of_disconnect_uv(struct xpc_channel *ch)
{
    struct xpc_send_msg_slot_uv *msg_slot;
    int entry;

    DBUG_ON(!(ch->flags & XPC_C_DISCONNECTING));

    for (entry = 0; entry < ch->local_nentries; entry++) {

        if (atomic_read(&ch->n_to_notify) == 0)
            break;

        msg_slot = &ch->sn.uv.send_msg_slots[entry];
        if (msg_slot->func != NULL)
            xpc_notify_sender_uv(ch, msg_slot, ch->reason);
    }
}

/*
 * Get the next deliverable message's payload.
 */
static void *
xpc_get_deliverable_payload_uv(struct xpc_channel *ch)
{
    struct xpc_fifo_entry_uv *entry;
    struct xpc_notify_mq_msg_uv *msg;
    void *payload = NULL;

    if (!(ch->flags & XPC_C_DISCONNECTING)) {
        entry = xpc_get_fifo_entry_uv(&ch->sn.uv.recv_msg_list);
        if (entry != NULL) {
            msg = container_of(entry, struct xpc_notify_mq_msg_uv,
                       hdr.u.next);
            payload = &msg->payload;
        }
    }
    return payload;
}

static void
xpc_received_payload_uv(struct xpc_channel *ch, void *payload)
{
    struct xpc_notify_mq_msg_uv *msg;
    enum xp_retval ret;

    msg = container_of(payload, struct xpc_notify_mq_msg_uv, payload);

    /* return an ACK to the sender of this message */

    msg->hdr.partid = xp_partition_id;
    msg->hdr.size = 0;  /* size of zero indicates this is an ACK */

    ret = xpc_send_gru_msg(ch->sn.uv.cached_notify_gru_mq_desc, msg,
                   sizeof(struct xpc_notify_mq_msghdr_uv));
    if (ret != xpSuccess)
        XPC_DEACTIVATE_PARTITION(&xpc_partitions[ch->partid], ret);
}

static struct xpc_arch_operations xpc_arch_ops_uv = {
    .setup_partitions = xpc_setup_partitions_uv,
    .teardown_partitions = xpc_teardown_partitions_uv,
    .process_activate_IRQ_rcvd = xpc_process_activate_IRQ_rcvd_uv,
    .get_partition_rsvd_page_pa = xpc_get_partition_rsvd_page_pa_uv,
    .setup_rsvd_page = xpc_setup_rsvd_page_uv,

    .allow_hb = xpc_allow_hb_uv,
    .disallow_hb = xpc_disallow_hb_uv,
    .disallow_all_hbs = xpc_disallow_all_hbs_uv,
    .increment_heartbeat = xpc_increment_heartbeat_uv,
    .offline_heartbeat = xpc_offline_heartbeat_uv,
    .online_heartbeat = xpc_online_heartbeat_uv,
    .heartbeat_init = xpc_heartbeat_init_uv,
    .heartbeat_exit = xpc_heartbeat_exit_uv,
    .get_remote_heartbeat = xpc_get_remote_heartbeat_uv,

    .request_partition_activation =
        xpc_request_partition_activation_uv,
    .request_partition_reactivation =
        xpc_request_partition_reactivation_uv,
    .request_partition_deactivation =
        xpc_request_partition_deactivation_uv,
    .cancel_partition_deactivation_request =
        xpc_cancel_partition_deactivation_request_uv,

    .setup_ch_structures = xpc_setup_ch_structures_uv,
    .teardown_ch_structures = xpc_teardown_ch_structures_uv,

    .make_first_contact = xpc_make_first_contact_uv,

    .get_chctl_all_flags = xpc_get_chctl_all_flags_uv,
    .send_chctl_closerequest = xpc_send_chctl_closerequest_uv,
    .send_chctl_closereply = xpc_send_chctl_closereply_uv,
    .send_chctl_openrequest = xpc_send_chctl_openrequest_uv,
    .send_chctl_openreply = xpc_send_chctl_openreply_uv,
    .send_chctl_opencomplete = xpc_send_chctl_opencomplete_uv,
    .process_msg_chctl_flags = xpc_process_msg_chctl_flags_uv,

    .save_remote_msgqueue_pa = xpc_save_remote_msgqueue_pa_uv,

    .setup_msg_structures = xpc_setup_msg_structures_uv,
    .teardown_msg_structures = xpc_teardown_msg_structures_uv,

    .indicate_partition_engaged = xpc_indicate_partition_engaged_uv,
    .indicate_partition_disengaged = xpc_indicate_partition_disengaged_uv,
    .assume_partition_disengaged = xpc_assume_partition_disengaged_uv,
    .partition_engaged = xpc_partition_engaged_uv,
    .any_partition_engaged = xpc_any_partition_engaged_uv,

    .n_of_deliverable_payloads = xpc_n_of_deliverable_payloads_uv,
    .send_payload = xpc_send_payload_uv,
    .get_deliverable_payload = xpc_get_deliverable_payload_uv,
    .received_payload = xpc_received_payload_uv,
    .notify_senders_of_disconnect = xpc_notify_senders_of_disconnect_uv,
};

static int
xpc_init_mq_node(int nid)
{
    int cpu;

    get_online_cpus();

    for_each_cpu(cpu, cpumask_of_node(nid)) {
        xpc_activate_mq_uv =
            xpc_create_gru_mq_uv(XPC_ACTIVATE_MQ_SIZE_UV, nid,
                         XPC_ACTIVATE_IRQ_NAME,
                         xpc_handle_activate_IRQ_uv);
        if (!IS_ERR(xpc_activate_mq_uv))
            break;
    }
    if (IS_ERR(xpc_activate_mq_uv)) {
        put_online_cpus();
        return PTR_ERR(xpc_activate_mq_uv);
    }

    for_each_cpu(cpu, cpumask_of_node(nid)) {
        xpc_notify_mq_uv =
            xpc_create_gru_mq_uv(XPC_NOTIFY_MQ_SIZE_UV, nid,
                         XPC_NOTIFY_IRQ_NAME,
                         xpc_handle_notify_IRQ_uv);
        if (!IS_ERR(xpc_notify_mq_uv))
            break;
    }
    if (IS_ERR(xpc_notify_mq_uv)) {
        xpc_destroy_gru_mq_uv(xpc_activate_mq_uv);
        put_online_cpus();
        return PTR_ERR(xpc_notify_mq_uv);
    }

    put_online_cpus();
    return 0;
}

int
xpc_init_uv(void)
{
    int nid;
    int ret = 0;

    xpc_arch_ops = xpc_arch_ops_uv;

    if (sizeof(struct xpc_notify_mq_msghdr_uv) > XPC_MSG_HDR_MAX_SIZE) {
        dev_err(xpc_part, "xpc_notify_mq_msghdr_uv is larger than %d\n",
            XPC_MSG_HDR_MAX_SIZE);
        return -E2BIG;
    }

    if (xpc_mq_node < 0)
        for_each_online_node(nid) {
            ret = xpc_init_mq_node(nid);

            if (!ret)
                break;
        }
    else
        ret = xpc_init_mq_node(xpc_mq_node);

    if (ret < 0)
        dev_err(xpc_part, "xpc_init_mq_node() returned error=%d\n",
            -ret);

    return ret;
}

void
xpc_exit_uv(void)
{
    xpc_destroy_gru_mq_uv(xpc_notify_mq_uv);
    xpc_destroy_gru_mq_uv(xpc_activate_mq_uv);
}

module_param(xpc_mq_node, int, 0);
MODULE_PARM_DESC(xpc_mq_node, "Node number on which to allocate message queues.");