ipath_keys.c

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/*
 * Copyright (c) 2006, 2007 QLogic Corporation. All rights reserved.
 * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <asm/io.h>

#include "ipath_verbs.h"
#include "ipath_kernel.h"

int ipath_alloc_lkey(struct ipath_lkey_table *rkt, struct ipath_mregion *mr)
{
    unsigned long flags;
    u32 r;
    u32 n;
    int ret;

    spin_lock_irqsave(&rkt->lock, flags);

    /* Find the next available LKEY */
    r = n = rkt->next;
    for (;;) {
        if (rkt->table[r] == NULL)
            break;
        r = (r + 1) & (rkt->max - 1);
        if (r == n) {
            spin_unlock_irqrestore(&rkt->lock, flags);
            ipath_dbg("LKEY table full\n");
            ret = 0;
            goto bail;
        }
    }
    rkt->next = (r + 1) & (rkt->max - 1);
    /*
     * Make sure lkey is never zero which is reserved to indicate an
     * unrestricted LKEY.
     */
    rkt->gen++;
    mr->lkey = (r << (32 - ib_ipath_lkey_table_size)) |
        ((((1 << (24 - ib_ipath_lkey_table_size)) - 1) & rkt->gen)
         << 8);
    if (mr->lkey == 0) {
        mr->lkey |= 1 << 8;
        rkt->gen++;
    }
    rkt->table[r] = mr;
    spin_unlock_irqrestore(&rkt->lock, flags);

    ret = 1;

bail:
    return ret;
}

void ipath_free_lkey(struct ipath_lkey_table *rkt, u32 lkey)
{
    unsigned long flags;
    u32 r;

    if (lkey == 0)
        return;
    r = lkey >> (32 - ib_ipath_lkey_table_size);
    spin_lock_irqsave(&rkt->lock, flags);
    rkt->table[r] = NULL;
    spin_unlock_irqrestore(&rkt->lock, flags);
}

int ipath_lkey_ok(struct ipath_qp *qp, struct ipath_sge *isge,
          struct ib_sge *sge, int acc)
{
    struct ipath_lkey_table *rkt = &to_idev(qp->ibqp.device)->lk_table;
    struct ipath_mregion *mr;
    unsigned n, m;
    size_t off;
    int ret;

    /*
     * We use LKEY == zero for kernel virtual addresses
     * (see ipath_get_dma_mr and ipath_dma.c).
     */
    if (sge->lkey == 0) {
        /* always a kernel port, no locking needed */
        struct ipath_pd *pd = to_ipd(qp->ibqp.pd);

        if (pd->user) {
            ret = 0;
            goto bail;
        }
        isge->mr = NULL;
        isge->vaddr = (void *) sge->addr;
        isge->length = sge->length;
        isge->sge_length = sge->length;
        ret = 1;
        goto bail;
    }
    mr = rkt->table[(sge->lkey >> (32 - ib_ipath_lkey_table_size))];
    if (unlikely(mr == NULL || mr->lkey != sge->lkey ||
             qp->ibqp.pd != mr->pd)) {
        ret = 0;
        goto bail;
    }

    off = sge->addr - mr->user_base;
    if (unlikely(sge->addr < mr->user_base ||
             off + sge->length > mr->length ||
             (mr->access_flags & acc) != acc)) {
        ret = 0;
        goto bail;
    }

    off += mr->offset;
    m = 0;
    n = 0;
    while (off >= mr->map[m]->segs[n].length) {
        off -= mr->map[m]->segs[n].length;
        n++;
        if (n >= IPATH_SEGSZ) {
            m++;
            n = 0;
        }
    }
    isge->mr = mr;
    isge->vaddr = mr->map[m]->segs[n].vaddr + off;
    isge->length = mr->map[m]->segs[n].length - off;
    isge->sge_length = sge->length;
    isge->m = m;
    isge->n = n;

    ret = 1;

bail:
    return ret;
}

int ipath_rkey_ok(struct ipath_qp *qp, struct ipath_sge_state *ss,
          u32 len, u64 vaddr, u32 rkey, int acc)
{
    struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
    struct ipath_lkey_table *rkt = &dev->lk_table;
    struct ipath_sge *sge = &ss->sge;
    struct ipath_mregion *mr;
    unsigned n, m;
    size_t off;
    int ret;

    /*
     * We use RKEY == zero for kernel virtual addresses
     * (see ipath_get_dma_mr and ipath_dma.c).
     */
    if (rkey == 0) {
        /* always a kernel port, no locking needed */
        struct ipath_pd *pd = to_ipd(qp->ibqp.pd);

        if (pd->user) {
            ret = 0;
            goto bail;
        }
        sge->mr = NULL;
        sge->vaddr = (void *) vaddr;
        sge->length = len;
        sge->sge_length = len;
        ss->sg_list = NULL;
        ss->num_sge = 1;
        ret = 1;
        goto bail;
    }

    mr = rkt->table[(rkey >> (32 - ib_ipath_lkey_table_size))];
    if (unlikely(mr == NULL || mr->lkey != rkey ||
             qp->ibqp.pd != mr->pd)) {
        ret = 0;
        goto bail;
    }

    off = vaddr - mr->iova;
    if (unlikely(vaddr < mr->iova || off + len > mr->length ||
             (mr->access_flags & acc) == 0)) {
        ret = 0;
        goto bail;
    }

    off += mr->offset;
    m = 0;
    n = 0;
    while (off >= mr->map[m]->segs[n].length) {
        off -= mr->map[m]->segs[n].length;
        n++;
        if (n >= IPATH_SEGSZ) {
            m++;
            n = 0;
        }
    }
    sge->mr = mr;
    sge->vaddr = mr->map[m]->segs[n].vaddr + off;
    sge->length = mr->map[m]->segs[n].length - off;
    sge->sge_length = len;
    sge->m = m;
    sge->n = n;
    ss->sg_list = NULL;
    ss->num_sge = 1;

    ret = 1;

bail:
    return ret;
}