/*
 * Copyright (c) 2006, 2007, 2008, 2009 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 <rdma/ib_umem.h>
#include <rdma/ib_smi.h>

#include "qib.h"

/* Fast memory region */
struct qib_fmr {
        struct ib_fmr ibfmr;
        struct qib_mregion mr;        /* must be last */
};

static inline struct qib_fmr *to_ifmr(struct ib_fmr *ibfmr)
{
        return container_of(ibfmr, struct qib_fmr, ibfmr);
}

static int init_qib_mregion(struct qib_mregion *mr, struct ib_pd *pd,
        int count)
{
        int m, i = 0;
        int rval = 0;

        m = (count + QIB_SEGSZ - 1) / QIB_SEGSZ;
        for (; i < m; i++) {
                mr->map[i] = kzalloc(sizeof *mr->map[0], GFP_KERNEL);
                if (!mr->map[i])
                        goto bail;
        }
        mr->mapsz = m;
        init_completion(&mr->comp);
        /* count returning the ptr to user */
        atomic_set(&mr->refcount, 1);
        mr->pd = pd;
        mr->max_segs = count;
out:
        return rval;
bail:
        while (i)
                kfree(mr->map[--i]);
        rval = -ENOMEM;
        goto out;
}

static void deinit_qib_mregion(struct qib_mregion *mr)
{
        int i = mr->mapsz;

        mr->mapsz = 0;
        while (i)
                kfree(mr->map[--i]);
}


/**
 * qib_get_dma_mr - get a DMA memory region
 * @pd: protection domain for this memory region
 * @acc: access flags
 *
 * Returns the memory region on success, otherwise returns an errno.
 * Note that all DMA addresses should be created via the
 * struct ib_dma_mapping_ops functions (see qib_dma.c).
 */
struct ib_mr *qib_get_dma_mr(struct ib_pd *pd, int acc)
{
        struct qib_mr *mr = NULL;
        struct ib_mr *ret;
        int rval;

        if (to_ipd(pd)->user) {
                ret = ERR_PTR(-EPERM);
                goto bail;
        }

        mr = kzalloc(sizeof *mr, GFP_KERNEL);
        if (!mr) {
                ret = ERR_PTR(-ENOMEM);
                goto bail;
        }

        rval = init_qib_mregion(&mr->mr, pd, 0);
        if (rval) {
                ret = ERR_PTR(rval);
                goto bail;
        }


        rval = qib_alloc_lkey(&mr->mr, 1);
        if (rval) {
                ret = ERR_PTR(rval);
                goto bail_mregion;
        }

        mr->mr.access_flags = acc;
        ret = &mr->ibmr;
done:
        return ret;

bail_mregion:
        deinit_qib_mregion(&mr->mr);
bail:
        kfree(mr);
        goto done;
}

static struct qib_mr *alloc_mr(int count, struct ib_pd *pd)
{
        struct qib_mr *mr;
        int rval = -ENOMEM;
        int m;

        /* Allocate struct plus pointers to first level page tables. */
        m = (count + QIB_SEGSZ - 1) / QIB_SEGSZ;
        mr = kzalloc(sizeof *mr + m * sizeof mr->mr.map[0], GFP_KERNEL);
        if (!mr)
                goto bail;

        rval = init_qib_mregion(&mr->mr, pd, count);
        if (rval)
                goto bail;
        /*
         * ib_reg_phys_mr() will initialize mr->ibmr except for
         * lkey and rkey.
         */
        rval = qib_alloc_lkey(&mr->mr, 0);
        if (rval)
                goto bail_mregion;
        mr->ibmr.lkey = mr->mr.lkey;
        mr->ibmr.rkey = mr->mr.lkey;
done:
        return mr;

bail_mregion:
        deinit_qib_mregion(&mr->mr);
bail:
        kfree(mr);
        mr = ERR_PTR(rval);
        goto done;
}

/**
 * qib_reg_phys_mr - register a physical memory region
 * @pd: protection domain for this memory region
 * @buffer_list: pointer to the list of physical buffers to register
 * @num_phys_buf: the number of physical buffers to register
 * @iova_start: the starting address passed over IB which maps to this MR
 *
 * Returns the memory region on success, otherwise returns an errno.
 */
struct ib_mr *qib_reg_phys_mr(struct ib_pd *pd,
                              struct ib_phys_buf *buffer_list,
                              int num_phys_buf, int acc, u64 *iova_start)
{
        struct qib_mr *mr;
        int n, m, i;
        struct ib_mr *ret;

        mr = alloc_mr(num_phys_buf, pd);
        if (IS_ERR(mr)) {
                ret = (struct ib_mr *)mr;
                goto bail;
        }

        mr->mr.user_base = *iova_start;
        mr->mr.iova = *iova_start;
        mr->mr.access_flags = acc;

        m = 0;
        n = 0;
        for (i = 0; i < num_phys_buf; i++) {
                mr->mr.map[m]->segs[n].vaddr = (void *) buffer_list[i].addr;
                mr->mr.map[m]->segs[n].length = buffer_list[i].size;
                mr->mr.length += buffer_list[i].size;
                n++;
                if (n == QIB_SEGSZ) {
                        m++;
                        n = 0;
                }
        }

        ret = &mr->ibmr;

bail:
        return ret;
}

/**
 * qib_reg_user_mr - register a userspace memory region
 * @pd: protection domain for this memory region
 * @start: starting userspace address
 * @length: length of region to register
 * @mr_access_flags: access flags for this memory region
 * @udata: unused by the QLogic_IB driver
 *
 * Returns the memory region on success, otherwise returns an errno.
 */
struct ib_mr *qib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
                              u64 virt_addr, int mr_access_flags,
                              struct ib_udata *udata)
{
        struct qib_mr *mr;
        struct ib_umem *umem;
        struct ib_umem_chunk *chunk;
        int n, m, i;
        struct ib_mr *ret;

        if (length == 0) {
                ret = ERR_PTR(-EINVAL);
                goto bail;
        }

        umem = ib_umem_get(pd->uobject->context, start, length,
                           mr_access_flags, 0);
        if (IS_ERR(umem))
                return (void *) umem;

        n = 0;
        list_for_each_entry(chunk, &umem->chunk_list, list)
                n += chunk->nents;

        mr = alloc_mr(n, pd);
        if (IS_ERR(mr)) {
                ret = (struct ib_mr *)mr;
                ib_umem_release(umem);
                goto bail;
        }

        mr->mr.user_base = start;
        mr->mr.iova = virt_addr;
        mr->mr.length = length;
        mr->mr.offset = umem->offset;
        mr->mr.access_flags = mr_access_flags;
        mr->umem = umem;

        if (is_power_of_2(umem->page_size))
                mr->mr.page_shift = ilog2(umem->page_size);
        m = 0;
        n = 0;
        list_for_each_entry(chunk, &umem->chunk_list, list) {
                for (i = 0; i < chunk->nents; i++) {
                        void *vaddr;

                        vaddr = page_address(sg_page(&chunk->page_list[i]));
                        if (!vaddr) {
                                ret = ERR_PTR(-EINVAL);
                                goto bail;
                        }
                        mr->mr.map[m]->segs[n].vaddr = vaddr;
                        mr->mr.map[m]->segs[n].length = umem->page_size;
                        n++;
                        if (n == QIB_SEGSZ) {
                                m++;
                                n = 0;
                        }
                }
        }
        ret = &mr->ibmr;

bail:
        return ret;
}

/**
 * qib_dereg_mr - unregister and free a memory region
 * @ibmr: the memory region to free
 *
 * Returns 0 on success.
 *
 * Note that this is called to free MRs created by qib_get_dma_mr()
 * or qib_reg_user_mr().
 */
int qib_dereg_mr(struct ib_mr *ibmr)
{
        struct qib_mr *mr = to_imr(ibmr);
        int ret = 0;
        unsigned long timeout;

        qib_free_lkey(&mr->mr);

        qib_put_mr(&mr->mr); /* will set completion if last */
        timeout = wait_for_completion_timeout(&mr->mr.comp,
                5 * HZ);
        if (!timeout) {
                qib_get_mr(&mr->mr);
                ret = -EBUSY;
                goto out;
        }
        deinit_qib_mregion(&mr->mr);
        if (mr->umem)
                ib_umem_release(mr->umem);
        kfree(mr);
out:
        return ret;
}

/*
 * Allocate a memory region usable with the
 * IB_WR_FAST_REG_MR send work request.
 *
 * Return the memory region on success, otherwise return an errno.
 */
struct ib_mr *qib_alloc_fast_reg_mr(struct ib_pd *pd, int max_page_list_len)
{
        struct qib_mr *mr;

        mr = alloc_mr(max_page_list_len, pd);
        if (IS_ERR(mr))
                return (struct ib_mr *)mr;

        return &mr->ibmr;
}

struct ib_fast_reg_page_list *
qib_alloc_fast_reg_page_list(struct ib_device *ibdev, int page_list_len)
{
        unsigned size = page_list_len * sizeof(u64);
        struct ib_fast_reg_page_list *pl;

        if (size > PAGE_SIZE)
                return ERR_PTR(-EINVAL);

        pl = kzalloc(sizeof *pl, GFP_KERNEL);
        if (!pl)
                return ERR_PTR(-ENOMEM);

        pl->page_list = kzalloc(size, GFP_KERNEL);
        if (!pl->page_list)
                goto err_free;

        return pl;

err_free:
        kfree(pl);
        return ERR_PTR(-ENOMEM);
}

void qib_free_fast_reg_page_list(struct ib_fast_reg_page_list *pl)
{
        kfree(pl->page_list);
        kfree(pl);
}

/**
 * qib_alloc_fmr - allocate a fast memory region
 * @pd: the protection domain for this memory region
 * @mr_access_flags: access flags for this memory region
 * @fmr_attr: fast memory region attributes
 *
 * Returns the memory region on success, otherwise returns an errno.
 */
struct ib_fmr *qib_alloc_fmr(struct ib_pd *pd, int mr_access_flags,
                             struct ib_fmr_attr *fmr_attr)
{
        struct qib_fmr *fmr;
        int m;
        struct ib_fmr *ret;
        int rval = -ENOMEM;

        /* Allocate struct plus pointers to first level page tables. */
        m = (fmr_attr->max_pages + QIB_SEGSZ - 1) / QIB_SEGSZ;
        fmr = kzalloc(sizeof *fmr + m * sizeof fmr->mr.map[0], GFP_KERNEL);
        if (!fmr)
                goto bail;

        rval = init_qib_mregion(&fmr->mr, pd, fmr_attr->max_pages);
        if (rval)
                goto bail;

        /*
         * ib_alloc_fmr() will initialize fmr->ibfmr except for lkey &
         * rkey.
         */
        rval = qib_alloc_lkey(&fmr->mr, 0);
        if (rval)
                goto bail_mregion;
        fmr->ibfmr.rkey = fmr->mr.lkey;
        fmr->ibfmr.lkey = fmr->mr.lkey;
        /*
         * Resources are allocated but no valid mapping (RKEY can't be
         * used).
         */
        fmr->mr.access_flags = mr_access_flags;
        fmr->mr.max_segs = fmr_attr->max_pages;
        fmr->mr.page_shift = fmr_attr->page_shift;

        ret = &fmr->ibfmr;
done:
        return ret;

bail_mregion:
        deinit_qib_mregion(&fmr->mr);
bail:
        kfree(fmr);
        ret = ERR_PTR(rval);
        goto done;
}

/**
 * qib_map_phys_fmr - set up a fast memory region
 * @ibmfr: the fast memory region to set up
 * @page_list: the list of pages to associate with the fast memory region
 * @list_len: the number of pages to associate with the fast memory region
 * @iova: the virtual address of the start of the fast memory region
 *
 * This may be called from interrupt context.
 */

int qib_map_phys_fmr(struct ib_fmr *ibfmr, u64 *page_list,
                     int list_len, u64 iova)
{
        struct qib_fmr *fmr = to_ifmr(ibfmr);
        struct qib_lkey_table *rkt;
        unsigned long flags;
        int m, n, i;
        u32 ps;
        int ret;

        i = atomic_read(&fmr->mr.refcount);
        if (i > 2)
                return -EBUSY;

        if (list_len > fmr->mr.max_segs) {
                ret = -EINVAL;
                goto bail;
        }
        rkt = &to_idev(ibfmr->device)->lk_table;
        spin_lock_irqsave(&rkt->lock, flags);
        fmr->mr.user_base = iova;
        fmr->mr.iova = iova;
        ps = 1 << fmr->mr.page_shift;
        fmr->mr.length = list_len * ps;
        m = 0;
        n = 0;
        for (i = 0; i < list_len; i++) {
                fmr->mr.map[m]->segs[n].vaddr = (void *) page_list[i];
                fmr->mr.map[m]->segs[n].length = ps;
                if (++n == QIB_SEGSZ) {
                        m++;
                        n = 0;
                }
        }
        spin_unlock_irqrestore(&rkt->lock, flags);
        ret = 0;

bail:
        return ret;
}

/**
 * qib_unmap_fmr - unmap fast memory regions
 * @fmr_list: the list of fast memory regions to unmap
 *
 * Returns 0 on success.
 */
int qib_unmap_fmr(struct list_head *fmr_list)
{
        struct qib_fmr *fmr;
        struct qib_lkey_table *rkt;
        unsigned long flags;

        list_for_each_entry(fmr, fmr_list, ibfmr.list) {
                rkt = &to_idev(fmr->ibfmr.device)->lk_table;
                spin_lock_irqsave(&rkt->lock, flags);
                fmr->mr.user_base = 0;
                fmr->mr.iova = 0;
                fmr->mr.length = 0;
                spin_unlock_irqrestore(&rkt->lock, flags);
        }
        return 0;
}

/**
 * qib_dealloc_fmr - deallocate a fast memory region
 * @ibfmr: the fast memory region to deallocate
 *
 * Returns 0 on success.
 */
int qib_dealloc_fmr(struct ib_fmr *ibfmr)
{
        struct qib_fmr *fmr = to_ifmr(ibfmr);
        int ret = 0;
        unsigned long timeout;

        qib_free_lkey(&fmr->mr);
        qib_put_mr(&fmr->mr); /* will set completion if last */
        timeout = wait_for_completion_timeout(&fmr->mr.comp,
                5 * HZ);
        if (!timeout) {
                qib_get_mr(&fmr->mr);
                ret = -EBUSY;
                goto out;
        }
        deinit_qib_mregion(&fmr->mr);
        kfree(fmr);
out:
        return ret;
}

void mr_rcu_callback(struct rcu_head *list)
{
        struct qib_mregion *mr = container_of(list, struct qib_mregion, list);

        complete(&mr->comp);
}