/*
 * 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 <linux/slab.h>

#include <rdma/ib_umem.h>
#include <rdma/ib_pack.h>
#include <rdma/ib_smi.h>

#include "ipath_verbs.h"

/* Fast memory region */
struct ipath_fmr {
        struct ib_fmr ibfmr;
        u8 page_shift;
        struct ipath_mregion mr;        /* must be last */
};

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

/**
 * ipath_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 ipath_dma.c).
 */
struct ib_mr *ipath_get_dma_mr(struct ib_pd *pd, int acc)
{
        struct ipath_mr *mr;
        struct ib_mr *ret;

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

        mr->mr.access_flags = acc;
        ret = &mr->ibmr;

bail:
        return ret;
}

static struct ipath_mr *alloc_mr(int count,
                                 struct ipath_lkey_table *lk_table)
{
        struct ipath_mr *mr;
        int m, i = 0;

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

        /* Allocate first level page tables. */
        for (; i < m; i++) {
                mr->mr.map[i] = kmalloc(sizeof *mr->mr.map[0], GFP_KERNEL);
                if (!mr->mr.map[i])
                        goto bail;
        }
        mr->mr.mapsz = m;

        /*
         * ib_reg_phys_mr() will initialize mr->ibmr except for
         * lkey and rkey.
         */
        if (!ipath_alloc_lkey(lk_table, &mr->mr))
                goto bail;
        mr->ibmr.rkey = mr->ibmr.lkey = mr->mr.lkey;

        goto done;

bail:
        while (i) {
                i--;
                kfree(mr->mr.map[i]);
        }
        kfree(mr);
        mr = NULL;

done:
        return mr;
}

/**
 * ipath_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 *ipath_reg_phys_mr(struct ib_pd *pd,
                                struct ib_phys_buf *buffer_list,
                                int num_phys_buf, int acc, u64 *iova_start)
{
        struct ipath_mr *mr;
        int n, m, i;
        struct ib_mr *ret;

        mr = alloc_mr(num_phys_buf, &to_idev(pd->device)->lk_table);
        if (mr == NULL) {
                ret = ERR_PTR(-ENOMEM);
                goto bail;
        }

        mr->mr.pd = pd;
        mr->mr.user_base = *iova_start;
        mr->mr.iova = *iova_start;
        mr->mr.length = 0;
        mr->mr.offset = 0;
        mr->mr.access_flags = acc;
        mr->mr.max_segs = num_phys_buf;
        mr->umem = NULL;

        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 == IPATH_SEGSZ) {
                        m++;
                        n = 0;
                }
        }

        ret = &mr->ibmr;

bail:
        return ret;
}

/**
 * ipath_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
 * @virt_addr: virtual address to use (from HCA's point of view)
 * @mr_access_flags: access flags for this memory region
 * @udata: unused by the InfiniPath driver
 *
 * Returns the memory region on success, otherwise returns an errno.
 */
struct ib_mr *ipath_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
                                u64 virt_addr, int mr_access_flags,
                                struct ib_udata *udata)
{
        struct ipath_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, &to_idev(pd->device)->lk_table);
        if (!mr) {
                ret = ERR_PTR(-ENOMEM);
                ib_umem_release(umem);
                goto bail;
        }

        mr->mr.pd = pd;
        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->mr.max_segs = n;
        mr->umem = umem;

        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 == IPATH_SEGSZ) {
                                m++;
                                n = 0;
                        }
                }
        }
        ret = &mr->ibmr;

bail:
        return ret;
}

/**
 * ipath_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 ipath_get_dma_mr()
 * or ipath_reg_user_mr().
 */
int ipath_dereg_mr(struct ib_mr *ibmr)
{
        struct ipath_mr *mr = to_imr(ibmr);
        int i;

        ipath_free_lkey(&to_idev(ibmr->device)->lk_table, ibmr->lkey);
        i = mr->mr.mapsz;
        while (i) {
                i--;
                kfree(mr->mr.map[i]);
        }

        if (mr->umem)
                ib_umem_release(mr->umem);

        kfree(mr);
        return 0;
}

/**
 * ipath_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 *ipath_alloc_fmr(struct ib_pd *pd, int mr_access_flags,
                               struct ib_fmr_attr *fmr_attr)
{
        struct ipath_fmr *fmr;
        int m, i = 0;
        struct ib_fmr *ret;

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

        /* Allocate first level page tables. */
        for (; i < m; i++) {
                fmr->mr.map[i] = kmalloc(sizeof *fmr->mr.map[0],
                                         GFP_KERNEL);
                if (!fmr->mr.map[i])
                        goto bail;
        }
        fmr->mr.mapsz = m;

        /*
         * ib_alloc_fmr() will initialize fmr->ibfmr except for lkey &
         * rkey.
         */
        if (!ipath_alloc_lkey(&to_idev(pd->device)->lk_table, &fmr->mr))
                goto bail;
        fmr->ibfmr.rkey = fmr->ibfmr.lkey = fmr->mr.lkey;
        /*
         * Resources are allocated but no valid mapping (RKEY can't be
         * used).
         */
        fmr->mr.pd = pd;
        fmr->mr.user_base = 0;
        fmr->mr.iova = 0;
        fmr->mr.length = 0;
        fmr->mr.offset = 0;
        fmr->mr.access_flags = mr_access_flags;
        fmr->mr.max_segs = fmr_attr->max_pages;
        fmr->page_shift = fmr_attr->page_shift;

        ret = &fmr->ibfmr;
        goto done;

bail:
        while (i)
                kfree(fmr->mr.map[--i]);
        kfree(fmr);
        ret = ERR_PTR(-ENOMEM);

done:
        return ret;
}

/**
 * ipath_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 ipath_map_phys_fmr(struct ib_fmr *ibfmr, u64 * page_list,
                       int list_len, u64 iova)
{
        struct ipath_fmr *fmr = to_ifmr(ibfmr);
        struct ipath_lkey_table *rkt;
        unsigned long flags;
        int m, n, i;
        u32 ps;
        int ret;

        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->page_shift;
        fmr->mr.length = list_len * ps;
        m = 0;
        n = 0;
        ps = 1 << fmr->page_shift;
        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 == IPATH_SEGSZ) {
                        m++;
                        n = 0;
                }
        }
        spin_unlock_irqrestore(&rkt->lock, flags);
        ret = 0;

bail:
        return ret;
}

/**
 * ipath_unmap_fmr - unmap fast memory regions
 * @fmr_list: the list of fast memory regions to unmap
 *
 * Returns 0 on success.
 */
int ipath_unmap_fmr(struct list_head *fmr_list)
{
        struct ipath_fmr *fmr;
        struct ipath_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;
}

/**
 * ipath_dealloc_fmr - deallocate a fast memory region
 * @ibfmr: the fast memory region to deallocate
 *
 * Returns 0 on success.
 */
int ipath_dealloc_fmr(struct ib_fmr *ibfmr)
{
        struct ipath_fmr *fmr = to_ifmr(ibfmr);
        int i;

        ipath_free_lkey(&to_idev(ibfmr->device)->lk_table, ibfmr->lkey);
        i = fmr->mr.mapsz;
        while (i)
                kfree(fmr->mr.map[--i]);
        kfree(fmr);
        return 0;
}