io/xsvc/xsvc.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright 2016 Joyent, Inc.
 */

#include <sys/errno.h>
#include <sys/types.h>
#include <sys/conf.h>
#include <sys/kmem.h>
#include <sys/ddi.h>
#include <sys/stat.h>
#include <sys/sunddi.h>
#include <sys/file.h>
#include <sys/open.h>
#include <sys/modctl.h>
#include <sys/ddi_impldefs.h>
#include <vm/seg_kmem.h>
#include <sys/vmsystm.h>
#include <sys/sysmacros.h>
#include <sys/ddidevmap.h>
#include <sys/avl.h>
#ifdef __xpv
#include <sys/hypervisor.h>
#endif

#include <sys/xsvc.h>

/* total max memory which can be alloced with ioctl interface */
uint64_t xsvc_max_memory = 10 * 1024 * 1024;

extern void i86_va_map(caddr_t vaddr, struct as *asp, caddr_t kaddr);


static int xsvc_open(dev_t *devp, int flag, int otyp, cred_t *cred);
static int xsvc_close(dev_t devp, int flag, int otyp, cred_t *cred);
static int xsvc_ioctl(dev_t dev, int cmd, intptr_t arg, int mode, cred_t *cred,
    int *rval);
static int xsvc_devmap(dev_t dev, devmap_cookie_t dhp, offset_t off, size_t len,
    size_t *maplen, uint_t model);
static int xsvc_attach(dev_info_t *devi, ddi_attach_cmd_t cmd);
static int xsvc_detach(dev_info_t *devi, ddi_detach_cmd_t cmd);
static int xsvc_getinfo(dev_info_t *dip, ddi_info_cmd_t cmd, void *arg,
    void **result);

static  struct cb_ops xsvc_cb_ops = {
    xsvc_open,      /* cb_open */
    xsvc_close,     /* cb_close */
    nodev,          /* cb_strategy */
    nodev,          /* cb_print */
    nodev,          /* cb_dump */
    nodev,          /* cb_read */
    nodev,          /* cb_write */
    xsvc_ioctl,     /* cb_ioctl */
    xsvc_devmap,        /* cb_devmap */
    NULL,           /* cb_mmap */
    NULL,           /* cb_segmap */
    nochpoll,       /* cb_chpoll */
    ddi_prop_op,        /* cb_prop_op */
    NULL,           /* cb_stream */
    D_NEW | D_MP | D_64BIT | D_DEVMAP,  /* cb_flag */
    CB_REV
};

static struct dev_ops xsvc_dev_ops = {
    DEVO_REV,       /* devo_rev */
    0,          /* devo_refcnt */
    xsvc_getinfo,       /* devo_getinfo */
    nulldev,        /* devo_identify */
    nulldev,        /* devo_probe */
    xsvc_attach,        /* devo_attach */
    xsvc_detach,        /* devo_detach */
    nodev,          /* devo_reset */
    &xsvc_cb_ops,       /* devo_cb_ops */
    NULL,           /* devo_bus_ops */
    NULL,           /* power */
    ddi_quiesce_not_needed,     /* quiesce */
};

static struct modldrv xsvc_modldrv = {
    &mod_driverops,     /* Type of module.  This one is a driver */
    "xsvc driver",      /* Name of the module. */
    &xsvc_dev_ops,      /* driver ops */
};

static struct modlinkage xsvc_modlinkage = {
    MODREV_1,
    (void *) &xsvc_modldrv,
    NULL
};


static int xsvc_ioctl_alloc_memory(xsvc_state_t *state, void *arg, int mode);
static int xsvc_ioctl_flush_memory(xsvc_state_t *state, void *arg, int mode);
static int xsvc_ioctl_free_memory(xsvc_state_t *state, void *arg, int mode);
static int xsvc_mem_alloc(xsvc_state_t *state, uint64_t key,
    xsvc_mem_t **mp);
static void xsvc_mem_free(xsvc_state_t *state, xsvc_mem_t *mp);
static xsvc_mem_t *xsvc_mem_lookup(xsvc_state_t *state,
    uint64_t key);
static int xsvc_mnode_key_compare(const void *q, const void *e);
static int xsvc_umem_cookie_alloc(caddr_t kva, size_t size, int flags,
    ddi_umem_cookie_t *cookiep);
static void xsvc_umem_cookie_free(ddi_umem_cookie_t *cookiep);


void *xsvc_statep;

static ddi_device_acc_attr_t xsvc_device_attr = {
    DDI_DEVICE_ATTR_V0,
    DDI_NEVERSWAP_ACC,
    DDI_STRICTORDER_ACC
};

static int xsvc_devmap_map(devmap_cookie_t dhp, dev_t dev, uint_t flags,
    offset_t off, size_t len, void **pvtp);
static int xsvc_devmap_dup(devmap_cookie_t dhp, void *pvtp,
    devmap_cookie_t new_dhp, void **new_pvtp);
static void xsvc_devmap_unmap(devmap_cookie_t dhp, void *pvtp, offset_t off,
    size_t len, devmap_cookie_t new_dhp1, void **new_pvtp1,
    devmap_cookie_t new_dhp2, void **new_pvtp2);


static struct devmap_callback_ctl xsvc_callbk = {
    DEVMAP_OPS_REV,
    xsvc_devmap_map,
    NULL,
    xsvc_devmap_dup,
    xsvc_devmap_unmap
};


/*
 * _init()
 *
 */
int
_init(void)
{
    int err;

    err = ddi_soft_state_init(&xsvc_statep, sizeof (xsvc_state_t), 1);
    if (err != 0) {
        return (err);
    }

    err = mod_install(&xsvc_modlinkage);
    if (err != 0) {
        ddi_soft_state_fini(&xsvc_statep);
        return (err);
    }

    return (0);
}

/*
 * _info()
 *
 */
int
_info(struct modinfo *modinfop)
{
    return (mod_info(&xsvc_modlinkage, modinfop));
}

/*
 * _fini()
 *
 */
int
_fini(void)
{
    int err;

    err = mod_remove(&xsvc_modlinkage);
    if (err != 0) {
        return (err);
    }

    ddi_soft_state_fini(&xsvc_statep);

    return (0);
}

/*
 * xsvc_attach()
 *
 */
static int
xsvc_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
{
    xsvc_state_t *state;
    int maxallocmem;
    int instance;
    int err;


    switch (cmd) {
    case DDI_ATTACH:
        break;

    case DDI_RESUME:
        return (DDI_SUCCESS);

    default:
        return (DDI_FAILURE);
    }

    instance = ddi_get_instance(dip);
    err = ddi_soft_state_zalloc(xsvc_statep, instance);
    if (err != DDI_SUCCESS) {
        return (DDI_FAILURE);
    }
    state = ddi_get_soft_state(xsvc_statep, instance);
    if (state == NULL) {
        goto attachfail_get_soft_state;
    }

    state->xs_dip = dip;
    state->xs_instance = instance;

    /* Initialize allocation count */
    mutex_init(&state->xs_mutex, NULL, MUTEX_DRIVER, NULL);
    state->xs_currently_alloced = 0;

    mutex_init(&state->xs_cookie_mutex, NULL, MUTEX_DRIVER, NULL);

    /* create the minor node (for the ioctl) */
    err = ddi_create_minor_node(dip, "xsvc", S_IFCHR, instance, DDI_PSEUDO,
        0);
    if (err != DDI_SUCCESS) {
        goto attachfail_minor_node;
    }

    /*
     * the maxallocmem property will override the default (xsvc_max_memory).
     * This is the maximum total memory the ioctl will allow to be alloced.
     */
    maxallocmem = ddi_prop_get_int(DDI_DEV_T_ANY, state->xs_dip,
        DDI_PROP_DONTPASS, "maxallocmem", -1);
    if (maxallocmem >= 0) {
        xsvc_max_memory = maxallocmem * 1024;
    }

    /* Initialize list of memory allocs */
    mutex_init(&state->xs_mlist.ml_mutex, NULL, MUTEX_DRIVER, NULL);
    avl_create(&state->xs_mlist.ml_avl, xsvc_mnode_key_compare,
        sizeof (xsvc_mnode_t), offsetof(xsvc_mnode_t, mn_link));

    /* Report that driver was loaded */
    ddi_report_dev(dip);

    return (DDI_SUCCESS);

attachfail_minor_node:
    mutex_destroy(&state->xs_cookie_mutex);
    mutex_destroy(&state->xs_mutex);
attachfail_get_soft_state:
    (void) ddi_soft_state_free(xsvc_statep, instance);

    return (err);
}

/*
 * xsvc_detach()
 *
 */
static int
xsvc_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
    xsvc_state_t *state;
    xsvc_mnode_t *mnode;
    xsvc_mem_t *mp;
    int instance;


    instance = ddi_get_instance(dip);
    state = ddi_get_soft_state(xsvc_statep, instance);
    if (state == NULL) {
        return (DDI_FAILURE);
    }

    switch (cmd) {
    case DDI_DETACH:
        break;

    case DDI_SUSPEND:
        return (DDI_SUCCESS);

    default:
        return (DDI_FAILURE);
    }

    ddi_remove_minor_node(dip, NULL);

    /* Free any memory on list */
    while ((mnode = avl_first(&state->xs_mlist.ml_avl)) != NULL) {
        mp = mnode->mn_home;
        xsvc_mem_free(state, mp);
    }

    /* remove list */
    avl_destroy(&state->xs_mlist.ml_avl);
    mutex_destroy(&state->xs_mlist.ml_mutex);

    mutex_destroy(&state->xs_cookie_mutex);
    mutex_destroy(&state->xs_mutex);
    (void) ddi_soft_state_free(xsvc_statep, state->xs_instance);
    return (DDI_SUCCESS);
}

/*
 * xsvc_getinfo()
 *
 */
/*ARGSUSED*/
static int
xsvc_getinfo(dev_info_t *dip, ddi_info_cmd_t cmd, void *arg, void **result)
{
    xsvc_state_t *state;
    int instance;
    dev_t dev;
    int err;


    dev = (dev_t)arg;
    instance = getminor(dev);

    switch (cmd) {
    case DDI_INFO_DEVT2DEVINFO:
        state = ddi_get_soft_state(xsvc_statep, instance);
        if (state == NULL) {
            return (DDI_FAILURE);
        }
        *result = (void *)state->xs_dip;
        err = DDI_SUCCESS;
        break;

    case DDI_INFO_DEVT2INSTANCE:
        *result = (void *)(uintptr_t)instance;
        err = DDI_SUCCESS;
        break;

    default:
        err = DDI_FAILURE;
        break;
    }

    return (err);
}


/*
 * xsvc_open()
 *
 */
/*ARGSUSED*/
static int
xsvc_open(dev_t *devp, int flag, int otyp, cred_t *cred)
{
    xsvc_state_t *state;
    int instance;

    instance = getminor(*devp);
    state = ddi_get_soft_state(xsvc_statep, instance);
    if (state == NULL) {
        return (ENXIO);
    }

    return (0);
}

/*
 * xsvc_close()
 *
 */
/*ARGSUSED*/
static int
xsvc_close(dev_t devp, int flag, int otyp, cred_t *cred)
{
    return (0);
}

/*
 * xsvc_ioctl()
 *
 */
/*ARGSUSED*/
static int
xsvc_ioctl(dev_t dev, int cmd, intptr_t arg, int mode, cred_t *cred, int *rval)
{
    xsvc_state_t *state;
    int instance;
    int err;


    err = drv_priv(cred);
    if (err != 0) {
        return (EPERM);
    }
    instance = getminor(dev);
    if (instance == -1) {
        return (EBADF);
    }
    state = ddi_get_soft_state(xsvc_statep, instance);
    if (state == NULL) {
        return (EBADF);
    }

    switch (cmd) {
    case XSVC_ALLOC_MEM:
        err = xsvc_ioctl_alloc_memory(state, (void *)arg, mode);
        break;

    case XSVC_FREE_MEM:
        err = xsvc_ioctl_free_memory(state, (void *)arg, mode);
        break;

    case XSVC_FLUSH_MEM:
        err = xsvc_ioctl_flush_memory(state, (void *)arg, mode);
        break;

    default:
        err = ENXIO;
    }

    return (err);
}

/*
 * xsvc_ioctl_alloc_memory()
 *
 */
static int
xsvc_ioctl_alloc_memory(xsvc_state_t *state, void *arg, int mode)
{
    xsvc_mem_req_32 params32;
    xsvc_mloc_32 *usgl32;
    xsvc_mem_req params;
    xsvc_mloc_32 sgl32;
    xsvc_mloc *usgl;
    xsvc_mem_t *mp;
    xsvc_mloc sgl;
    uint64_t key;
    size_t size;
    int err;
    int i;


    /* Copy in the params, then get the size and key */
    if (ddi_model_convert_from(mode & FMODELS) == DDI_MODEL_ILP32) {
        err = ddi_copyin(arg, &params32, sizeof (xsvc_mem_req_32),
            mode);
        if (err != 0) {
            return (EFAULT);
        }

        key = (uint64_t)params32.xsvc_mem_reqid;
        size = P2ROUNDUP((size_t)params32.xsvc_mem_size, PAGESIZE);
    } else {
        err = ddi_copyin(arg, &params, sizeof (xsvc_mem_req), mode);
        if (err != 0) {
            return (EFAULT);
        }
        key = (uint64_t)params.xsvc_mem_reqid;
        size = P2ROUNDUP(params.xsvc_mem_size, PAGESIZE);
    }

    /*
     * make sure this doesn't put us over the maximum allowed to be
     * allocated
     */
    mutex_enter(&state->xs_mutex);
    if ((state->xs_currently_alloced + size) > xsvc_max_memory) {
        mutex_exit(&state->xs_mutex);
        return (EAGAIN);
    }
    state->xs_currently_alloced += size;
    mutex_exit(&state->xs_mutex);

    /* get state to track this memory */
    err = xsvc_mem_alloc(state, key, &mp);
    if (err != 0) {
        return (err);
    }
    mp->xm_size = size;

    /* allocate and bind the memory */
    mp->xm_dma_attr.dma_attr_version = DMA_ATTR_V0;
    mp->xm_dma_attr.dma_attr_count_max = (uint64_t)0xFFFFFFFF;
    mp->xm_dma_attr.dma_attr_burstsizes = 1;
    mp->xm_dma_attr.dma_attr_minxfer = 1;
    mp->xm_dma_attr.dma_attr_maxxfer = (uint64_t)0xFFFFFFFF;
    mp->xm_dma_attr.dma_attr_seg = (uint64_t)0xFFFFFFFF;
    mp->xm_dma_attr.dma_attr_granular = 1;
    mp->xm_dma_attr.dma_attr_flags = 0;

    /* Finish converting params */
    if (ddi_model_convert_from(mode & FMODELS) == DDI_MODEL_ILP32) {
        mp->xm_dma_attr.dma_attr_addr_lo = params32.xsvc_mem_addr_lo;
        mp->xm_dma_attr.dma_attr_addr_hi = params32.xsvc_mem_addr_hi;
        mp->xm_dma_attr.dma_attr_sgllen = params32.xsvc_mem_sgllen;
        usgl32 = (xsvc_mloc_32 *)(uintptr_t)params32.xsvc_sg_list;
        mp->xm_dma_attr.dma_attr_align = P2ROUNDUP(
            params32.xsvc_mem_align, PAGESIZE);
    } else {
        mp->xm_dma_attr.dma_attr_addr_lo = params.xsvc_mem_addr_lo;
        mp->xm_dma_attr.dma_attr_addr_hi = params.xsvc_mem_addr_hi;
        mp->xm_dma_attr.dma_attr_sgllen = params.xsvc_mem_sgllen;
        usgl = (xsvc_mloc *)(uintptr_t)params.xsvc_sg_list;
        mp->xm_dma_attr.dma_attr_align = P2ROUNDUP(
            params.xsvc_mem_align, PAGESIZE);
    }

    mp->xm_device_attr = xsvc_device_attr;

    err = ddi_dma_alloc_handle(state->xs_dip, &mp->xm_dma_attr,
        DDI_DMA_SLEEP, NULL, &mp->xm_dma_handle);
    if (err != DDI_SUCCESS) {
        err = EINVAL;
        goto allocfail_alloc_handle;
    }

    /* don't sleep here so we don't get stuck in contig alloc */
    err = ddi_dma_mem_alloc(mp->xm_dma_handle, mp->xm_size,
        &mp->xm_device_attr, DDI_DMA_CONSISTENT, DDI_DMA_DONTWAIT, NULL,
        &mp->xm_addr, &mp->xm_real_length, &mp->xm_mem_handle);
    if (err != DDI_SUCCESS) {
        err = EINVAL;
        goto allocfail_alloc_mem;
    }

    err = ddi_dma_addr_bind_handle(mp->xm_dma_handle, NULL, mp->xm_addr,
        mp->xm_size, DDI_DMA_RDWR | DDI_DMA_CONSISTENT, DDI_DMA_SLEEP,
        NULL, &mp->xm_cookie, &mp->xm_cookie_count);
    if (err != DDI_DMA_MAPPED) {
        err = EFAULT;
        goto allocfail_bind;
    }

    /* return sgl */
    for (i = 0; i < mp->xm_cookie_count; i++) {
        if (ddi_model_convert_from(mode & FMODELS) == DDI_MODEL_ILP32) {
            sgl32.mloc_addr = mp->xm_cookie.dmac_laddress;
            sgl32.mloc_size = mp->xm_cookie.dmac_size;
            err = ddi_copyout(&sgl32, &usgl32[i],
                sizeof (xsvc_mloc_32), mode);
            if (err != 0) {
                err = EFAULT;
                goto allocfail_copyout;
            }
        } else {
            sgl.mloc_addr = mp->xm_cookie.dmac_laddress;
            sgl.mloc_size = mp->xm_cookie.dmac_size;
            err = ddi_copyout(&sgl, &usgl[i], sizeof (xsvc_mloc),
                mode);
            if (err != 0) {
                err = EFAULT;
                goto allocfail_copyout;
            }
        }
        ddi_dma_nextcookie(mp->xm_dma_handle, &mp->xm_cookie);
    }

    /* set the last sgl entry to 0 to indicate cookie count */
    if (ddi_model_convert_from(mode & FMODELS) == DDI_MODEL_ILP32) {
        sgl32.mloc_addr = 0;
        sgl32.mloc_size = 0;
        err = ddi_copyout(&sgl32, &usgl32[i], sizeof (xsvc_mloc_32),
            mode);
        if (err != 0) {
            err = EFAULT;
            goto allocfail_copyout;
        }
    } else {
        sgl.mloc_addr = 0;
        sgl.mloc_size = 0;
        err = ddi_copyout(&sgl, &usgl[i], sizeof (xsvc_mloc), mode);
        if (err != 0) {
            err = EFAULT;
            goto allocfail_copyout;
        }
    }

    return (0);

allocfail_copyout:
    (void) ddi_dma_unbind_handle(mp->xm_dma_handle);
allocfail_bind:
    ddi_dma_mem_free(&mp->xm_mem_handle);
allocfail_alloc_mem:
    ddi_dma_free_handle(&mp->xm_dma_handle);
allocfail_alloc_handle:
    mp->xm_dma_handle = NULL;
    xsvc_mem_free(state, mp);

    mutex_enter(&state->xs_mutex);
    state->xs_currently_alloced = state->xs_currently_alloced - size;
    mutex_exit(&state->xs_mutex);

    return (err);
}

/*
 * xsvc_ioctl_flush_memory()
 *
 */
static int
xsvc_ioctl_flush_memory(xsvc_state_t *state, void *arg, int mode)
{
    xsvc_mem_req_32 params32;
    xsvc_mem_req params;
    xsvc_mem_t *mp;
    uint64_t key;
    int err;


    if (ddi_model_convert_from(mode & FMODELS) == DDI_MODEL_ILP32) {
        err = ddi_copyin(arg, &params32, sizeof (xsvc_mem_req_32),
            mode);
        if (err != 0) {
            return (EFAULT);
        }
        key = (uint64_t)params32.xsvc_mem_reqid;
    } else {
        err = ddi_copyin(arg, &params, sizeof (xsvc_mem_req), mode);
        if (err != 0) {
            return (EFAULT);
        }
        key = (uint64_t)params.xsvc_mem_reqid;
    }

    /* find the memory */
    mp = xsvc_mem_lookup(state, key);
    if (mp == NULL) {
        return (EINVAL);
    }

    (void) ddi_dma_sync(mp->xm_dma_handle, 0, 0, DDI_DMA_SYNC_FORCPU);

    return (0);
}


/*
 * xsvc_ioctl_free_memory()
 *
 */
static int
xsvc_ioctl_free_memory(xsvc_state_t *state, void *arg, int mode)
{
    xsvc_mem_req_32 params32;
    xsvc_mem_req params;
    xsvc_mem_t *mp;
    uint64_t key;
    int err;


    if (ddi_model_convert_from(mode & FMODELS) == DDI_MODEL_ILP32) {
        err = ddi_copyin(arg, &params32, sizeof (xsvc_mem_req_32),
            mode);
        if (err != 0) {
            return (EFAULT);
        }
        key = (uint64_t)params32.xsvc_mem_reqid;
    } else {
        err = ddi_copyin(arg, &params, sizeof (xsvc_mem_req), mode);
        if (err != 0) {
            return (EFAULT);
        }
        key = (uint64_t)params.xsvc_mem_reqid;
    }

    /* find the memory */
    mp = xsvc_mem_lookup(state, key);
    if (mp == NULL) {
        return (EINVAL);
    }

    xsvc_mem_free(state, mp);

    return (0);
}

/*
 * xsvc_mem_alloc()
 *
 */
static int
xsvc_mem_alloc(xsvc_state_t *state, uint64_t key, xsvc_mem_t **mp)
{
    xsvc_mem_t *mem;

    mem = xsvc_mem_lookup(state, key);
    if (mem != NULL) {
        xsvc_mem_free(state, mem);
    }

    *mp = kmem_alloc(sizeof (xsvc_mem_t), KM_SLEEP);
    (*mp)->xm_mnode.mn_home = *mp;
    (*mp)->xm_mnode.mn_key = key;

    mutex_enter(&state->xs_mlist.ml_mutex);
    avl_add(&state->xs_mlist.ml_avl, &(*mp)->xm_mnode);
    mutex_exit(&state->xs_mlist.ml_mutex);

    return (0);
}

/*
 * xsvc_mem_free()
 *
 */
static void
xsvc_mem_free(xsvc_state_t *state, xsvc_mem_t *mp)
{
    if (mp->xm_dma_handle != NULL) {
        (void) ddi_dma_unbind_handle(mp->xm_dma_handle);
        ddi_dma_mem_free(&mp->xm_mem_handle);
        ddi_dma_free_handle(&mp->xm_dma_handle);

        mutex_enter(&state->xs_mutex);
        state->xs_currently_alloced = state->xs_currently_alloced -
            mp->xm_size;
        mutex_exit(&state->xs_mutex);
    }

    mutex_enter(&state->xs_mlist.ml_mutex);
    avl_remove(&state->xs_mlist.ml_avl, &mp->xm_mnode);
    mutex_exit(&state->xs_mlist.ml_mutex);

    kmem_free(mp, sizeof (*mp));
}

/*
 * xsvc_mem_lookup()
 *
 */
static xsvc_mem_t *
xsvc_mem_lookup(xsvc_state_t *state, uint64_t key)
{
    xsvc_mnode_t mnode;
    xsvc_mnode_t *mnp;
    avl_index_t where;
    xsvc_mem_t *mp;

    mnode.mn_key = key;
    mutex_enter(&state->xs_mlist.ml_mutex);
    mnp = avl_find(&state->xs_mlist.ml_avl, &mnode, &where);
    mutex_exit(&state->xs_mlist.ml_mutex);

    if (mnp != NULL) {
        mp = mnp->mn_home;
    } else {
        mp = NULL;
    }

    return (mp);
}

/*
 * xsvc_mnode_key_compare()
 *
 */
static int
xsvc_mnode_key_compare(const void *q, const void *e)
{
    xsvc_mnode_t *n1;
    xsvc_mnode_t *n2;

    n1 = (xsvc_mnode_t *)q;
    n2 = (xsvc_mnode_t *)e;

    if (n1->mn_key < n2->mn_key) {
        return (-1);
    } else if (n1->mn_key > n2->mn_key) {
        return (1);
    } else {
        return (0);
    }
}

/*
 * xsvc_devmap()
 *
 */
/*ARGSUSED*/
static int
xsvc_devmap(dev_t dev, devmap_cookie_t dhp, offset_t off, size_t len,
    size_t *maplen, uint_t model)
{
    ddi_umem_cookie_t cookie;
    xsvc_state_t *state;
    offset_t off_align;
    size_t npages;
    caddr_t kvai;
    size_t psize;
    int instance;
    caddr_t kva;
    pfn_t pfn;
    int err;
    int i;


    instance = getminor(dev);
    state = ddi_get_soft_state(xsvc_statep, instance);
    if (state == NULL) {
        return (ENXIO);
    }

    /*
     * On 64-bit kernels, if we have a 32-bit application doing a mmap(),
     * smmap32 will sign extend the offset. We need to undo that since
     * we are passed a physical address in off, not a offset.
     */
#if defined(__amd64)
    if (((model & DDI_MODEL_MASK) == DDI_MODEL_ILP32) &&
        ((off & ~0xFFFFFFFFll) == ~0xFFFFFFFFll)) {
        off = off & 0xFFFFFFFF;
    }
#endif

#ifdef __xpv
    /*
     * we won't allow guest OSes to devmap mfn/pfns. Maybe we'll relax
     * this some later when there is a good reason.
     */
    if (!DOMAIN_IS_INITDOMAIN(xen_info)) {
        return (-1);
    }

    /* we will always treat this as a foreign MFN */
    pfn = xen_assign_pfn(btop(off));
#else
    pfn = btop(off);
#endif
    /* always work with whole pages */

    off_align = P2ALIGN(off, PAGESIZE);
    psize = P2ROUNDUP(off + len, PAGESIZE) - off_align;

    /*
     * if this is memory we're trying to map into user space, we first
     * need to map the PFNs into KVA, then build up a umem cookie, and
     * finally do a umem_setup to map it in.
     */
    if (pf_is_memory(pfn)) {
        npages = btop(psize);

        kva = vmem_alloc(heap_arena, psize, VM_SLEEP);
        if (kva == NULL) {
            return (-1);
        }

        kvai = kva;
        for (i = 0; i < npages; i++) {
            page_t *pp = page_numtopp_nolock(pfn);

            /*
             * Preemptively check for panic conditions from
             * hat_devload and error out instead.
             */
            if (pp != NULL && (PP_ISFREE(pp) ||
                (!PAGE_LOCKED(pp) && !PP_ISNORELOC(pp)))) {
                err = DDI_FAILURE;
                npages = i;
                goto devmapfail_cookie_alloc;
            }

            hat_devload(kas.a_hat, kvai, PAGESIZE, pfn,
                PROT_READ | PROT_WRITE, HAT_LOAD_LOCK);
            pfn++;
            kvai = (caddr_t)((uintptr_t)kvai + PAGESIZE);
        }

        err = xsvc_umem_cookie_alloc(kva, psize, KM_SLEEP, &cookie);
        if (err != 0) {
            goto devmapfail_cookie_alloc;
        }

        if ((err = devmap_umem_setup(dhp, state->xs_dip, &xsvc_callbk,
            cookie, 0, psize, PROT_ALL, 0, &xsvc_device_attr)) < 0) {
            goto devmapfail_umem_setup;
        }
        *maplen = psize;

    /*
     * If this is not memory (or a foreign MFN in i86xpv), go through
     * devmem_setup.
     */
    } else {
        if ((err = devmap_devmem_setup(dhp, state->xs_dip, NULL, 0,
            off_align, psize, PROT_ALL, 0, &xsvc_device_attr)) < 0) {
            return (err);
        }
        *maplen = psize;
    }

    return (0);

devmapfail_umem_setup:
    xsvc_umem_cookie_free(&cookie);

devmapfail_cookie_alloc:
    kvai = kva;
    for (i = 0; i < npages; i++) {
        hat_unload(kas.a_hat, kvai, PAGESIZE,
            HAT_UNLOAD_UNLOCK);
        kvai = (caddr_t)((uintptr_t)kvai + PAGESIZE);
    }
    vmem_free(heap_arena, kva, psize);

    return (err);
}

/*
 * xsvc_umem_cookie_alloc()
 *
 *   allocate a umem cookie to be used in devmap_umem_setup using KVA already
 *   allocated.
 */
int
xsvc_umem_cookie_alloc(caddr_t kva, size_t size, int flags,
    ddi_umem_cookie_t *cookiep)
{
    struct ddi_umem_cookie *umem_cookiep;

    umem_cookiep = kmem_zalloc(sizeof (struct ddi_umem_cookie), flags);
    if (umem_cookiep == NULL) {
        *cookiep = NULL;
        return (-1);
    }

    umem_cookiep->cvaddr = kva;
    umem_cookiep->type = KMEM_NON_PAGEABLE;
    umem_cookiep->size = size;
    *cookiep = (ddi_umem_cookie_t *)umem_cookiep;

    return (0);
}

/*
 * xsvc_umem_cookie_free()
 *
 */
static void
xsvc_umem_cookie_free(ddi_umem_cookie_t *cookiep)
{
    kmem_free(*cookiep, sizeof (struct ddi_umem_cookie));
    *cookiep = NULL;
}


/*
 * xsvc_devmap_map()
 *
 */
/*ARGSUSED*/
static int
xsvc_devmap_map(devmap_cookie_t dhc, dev_t dev, uint_t flags, offset_t off,
    size_t len, void **pvtp)
{
    struct ddi_umem_cookie *cp;
    devmap_handle_t *dhp;
    xsvc_state_t *state;
    int instance;


    instance = getminor(dev);
    state = ddi_get_soft_state(xsvc_statep, instance);
    if (state == NULL) {
        return (ENXIO);
    }

    dhp = (devmap_handle_t *)dhc;
    /* This driver only supports MAP_SHARED, not MAP_PRIVATE */
    if (flags & MAP_PRIVATE) {
        cmn_err(CE_WARN, "!xsvc driver doesn't support MAP_PRIVATE");
        return (EINVAL);
    }

    cp = (struct ddi_umem_cookie *)dhp->dh_cookie;
    cp->cook_refcnt = 1;

    *pvtp = state;
    return (0);
}


/*
 * xsvc_devmap_dup()
 *
 *   keep a reference count for forks so we don't unmap if we have multiple
 *   mappings.
 */
/*ARGSUSED*/
static int
xsvc_devmap_dup(devmap_cookie_t dhc, void *pvtp, devmap_cookie_t new_dhp,
    void **new_pvtp)
{
    struct ddi_umem_cookie *cp;
    devmap_handle_t *dhp;
    xsvc_state_t *state;


    state = (xsvc_state_t *)pvtp;
    dhp = (devmap_handle_t *)dhc;

    mutex_enter(&state->xs_cookie_mutex);
    cp = (struct ddi_umem_cookie *)dhp->dh_cookie;
    if (cp == NULL) {
        mutex_exit(&state->xs_cookie_mutex);
        return (ENOMEM);
    }

    cp->cook_refcnt++;
    mutex_exit(&state->xs_cookie_mutex);

    *new_pvtp = state;
    return (0);
}


/*
 * xsvc_devmap_unmap()
 *
 *   This routine is only call if we were mapping in memory in xsvc_devmap().
 *   i.e. we only pass in xsvc_callbk to devmap_umem_setup if pf_is_memory()
 *   was true. It would have been nice if devmap_callback_ctl had an args param.
 *   We wouldn't have had to look into the devmap_handle and into the umem
 *   cookie.
 */
/*ARGSUSED*/
static void
xsvc_devmap_unmap(devmap_cookie_t dhc, void *pvtp, offset_t off, size_t len,
    devmap_cookie_t new_dhp1, void **new_pvtp1, devmap_cookie_t new_dhp2,
    void **new_pvtp2)
{
    struct ddi_umem_cookie *ncp;
    struct ddi_umem_cookie *cp;
    devmap_handle_t *ndhp;
    devmap_handle_t *dhp;
    xsvc_state_t *state;
    size_t npages;
    caddr_t kvai;
    caddr_t kva;
    size_t size;
    int i;


    state = (xsvc_state_t *)pvtp;
    mutex_enter(&state->xs_cookie_mutex);

    /* peek into the umem cookie to figure out what we need to free up */
    dhp = (devmap_handle_t *)dhc;
    cp = (struct ddi_umem_cookie *)dhp->dh_cookie;
    ASSERT(cp != NULL);

    if (new_dhp1 != NULL) {
        ndhp = (devmap_handle_t *)new_dhp1;
        ncp = (struct ddi_umem_cookie *)ndhp->dh_cookie;
        ncp->cook_refcnt++;
        *new_pvtp1 = state;
    }
    if (new_dhp2 != NULL) {
        ndhp = (devmap_handle_t *)new_dhp2;
        ncp = (struct ddi_umem_cookie *)ndhp->dh_cookie;
        ncp->cook_refcnt++;
        *new_pvtp2 = state;
    }

    cp->cook_refcnt--;
    if (cp->cook_refcnt == 0) {
        kva = cp->cvaddr;
        size = cp->size;

        /*
         * free up the umem cookie, then unmap all the pages what we
         * mapped in during devmap, then free up the kva space.
         */
        npages = btop(size);
        xsvc_umem_cookie_free(&dhp->dh_cookie);
        kvai = kva;
        for (i = 0; i < npages; i++) {
            hat_unload(kas.a_hat, kvai, PAGESIZE,
                HAT_UNLOAD_UNLOCK);
            kvai = (caddr_t)((uintptr_t)kvai + PAGESIZE);
        }
        vmem_free(heap_arena, kva, size);
    }

    mutex_exit(&state->xs_cookie_mutex);
}