/*
 * 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"

/**
 * ipath_alloc_lkey - allocate an lkey
 * @rkt: lkey table in which to allocate the lkey
 * @mr: memory region that this lkey protects
 *
 * Returns 1 if successful, otherwise returns 0.
 */

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;
}

/**
 * ipath_free_lkey - free an lkey
 * @rkt: table from which to free the lkey
 * @lkey: lkey id to free
 */
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);
}

/**
 * ipath_lkey_ok - check IB SGE for validity and initialize
 * @rkt: table containing lkey to check SGE against
 * @isge: outgoing internal SGE
 * @sge: SGE to check
 * @acc: access flags
 *
 * Return 1 if valid and successful, otherwise returns 0.
 *
 * Check the IB SGE for validity and initialize our internal version
 * of it.
 */
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;
}

/**
 * ipath_rkey_ok - check the IB virtual address, length, and RKEY
 * @dev: infiniband device
 * @ss: SGE state
 * @len: length of data
 * @vaddr: virtual address to place data
 * @rkey: rkey to check
 * @acc: access flags
 *
 * Return 1 if successful, otherwise 0.
 */
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;
}