/*
 * Copyright (c) 2006, 2007 Cisco Systems, Inc.  All rights reserved.
 * Copyright (c) 2007, 2008 Mellanox Technologies. 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/errno.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/export.h>
#include <linux/bitmap.h>
#include <linux/dma-mapping.h>
#include <linux/vmalloc.h>

#include "mlx4.h"

u32 mlx4_bitmap_alloc(struct mlx4_bitmap *bitmap)
{
        u32 obj;

        spin_lock(&bitmap->lock);

        obj = find_next_zero_bit(bitmap->table, bitmap->max, bitmap->last);
        if (obj >= bitmap->max) {
                bitmap->top = (bitmap->top + bitmap->max + bitmap->reserved_top)
                                & bitmap->mask;
                obj = find_first_zero_bit(bitmap->table, bitmap->max);
        }

        if (obj < bitmap->max) {
                set_bit(obj, bitmap->table);
                bitmap->last = (obj + 1);
                if (bitmap->last == bitmap->max)
                        bitmap->last = 0;
                obj |= bitmap->top;
        } else
                obj = -1;

        if (obj != -1)
                --bitmap->avail;

        spin_unlock(&bitmap->lock);

        return obj;
}

void mlx4_bitmap_free(struct mlx4_bitmap *bitmap, u32 obj, int use_rr)
{
        mlx4_bitmap_free_range(bitmap, obj, 1, use_rr);
}

static unsigned long find_aligned_range(unsigned long *bitmap,
                                        u32 start, u32 nbits,
                                        int len, int align, u32 skip_mask)
{
        unsigned long end, i;

again:
        start = ALIGN(start, align);

        while ((start < nbits) && (test_bit(start, bitmap) ||
                                   (start & skip_mask)))
                start += align;

        if (start >= nbits)
                return -1;

        end = start+len;
        if (end > nbits)
                return -1;

        for (i = start + 1; i < end; i++) {
                if (test_bit(i, bitmap) || ((u32)i & skip_mask)) {
                        start = i + 1;
                        goto again;
                }
        }

        return start;
}

u32 mlx4_bitmap_alloc_range(struct mlx4_bitmap *bitmap, int cnt,
                            int align, u32 skip_mask)
{
        u32 obj;

        if (likely(cnt == 1 && align == 1 && !skip_mask))
                return mlx4_bitmap_alloc(bitmap);

        spin_lock(&bitmap->lock);

        obj = find_aligned_range(bitmap->table, bitmap->last,
                                 bitmap->max, cnt, align, skip_mask);
        if (obj >= bitmap->max) {
                bitmap->top = (bitmap->top + bitmap->max + bitmap->reserved_top)
                                & bitmap->mask;
                obj = find_aligned_range(bitmap->table, 0, bitmap->max,
                                         cnt, align, skip_mask);
        }

        if (obj < bitmap->max) {
                bitmap_set(bitmap->table, obj, cnt);
                if (obj == bitmap->last) {
                        bitmap->last = (obj + cnt);
                        if (bitmap->last >= bitmap->max)
                                bitmap->last = 0;
                }
                obj |= bitmap->top;
        } else
                obj = -1;

        if (obj != -1)
                bitmap->avail -= cnt;

        spin_unlock(&bitmap->lock);

        return obj;
}

u32 mlx4_bitmap_avail(struct mlx4_bitmap *bitmap)
{
        return bitmap->avail;
}

static u32 mlx4_bitmap_masked_value(struct mlx4_bitmap *bitmap, u32 obj)
{
        return obj & (bitmap->max + bitmap->reserved_top - 1);
}

void mlx4_bitmap_free_range(struct mlx4_bitmap *bitmap, u32 obj, int cnt,
                            int use_rr)
{
        obj &= bitmap->max + bitmap->reserved_top - 1;

        spin_lock(&bitmap->lock);
        if (!use_rr) {
                bitmap->last = min(bitmap->last, obj);
                bitmap->top = (bitmap->top + bitmap->max + bitmap->reserved_top)
                                & bitmap->mask;
        }
        bitmap_clear(bitmap->table, obj, cnt);
        bitmap->avail += cnt;
        spin_unlock(&bitmap->lock);
}

int mlx4_bitmap_init(struct mlx4_bitmap *bitmap, u32 num, u32 mask,
                     u32 reserved_bot, u32 reserved_top)
{
        /* num must be a power of 2 */
        if (num != roundup_pow_of_two(num))
                return -EINVAL;

        bitmap->last = 0;
        bitmap->top  = 0;
        bitmap->max  = num - reserved_top;
        bitmap->mask = mask;
        bitmap->reserved_top = reserved_top;
        bitmap->avail = num - reserved_top - reserved_bot;
        bitmap->effective_len = bitmap->avail;
        spin_lock_init(&bitmap->lock);
        bitmap->table = bitmap_zalloc(bitmap->max, GFP_KERNEL);
        if (!bitmap->table)
                return -ENOMEM;

        bitmap_set(bitmap->table, 0, reserved_bot);

        return 0;
}

void mlx4_bitmap_cleanup(struct mlx4_bitmap *bitmap)
{
        bitmap_free(bitmap->table);
}

struct mlx4_zone_allocator {
        struct list_head                entries;
        struct list_head                prios;
        u32                             last_uid;
        u32                             mask;
        /* protect the zone_allocator from concurrent accesses */
        spinlock_t                      lock;
        enum mlx4_zone_alloc_flags      flags;
};

struct mlx4_zone_entry {
        struct list_head                list;
        struct list_head                prio_list;
        u32                             uid;
        struct mlx4_zone_allocator      *allocator;
        struct mlx4_bitmap              *bitmap;
        int                             use_rr;
        int                             priority;
        int                             offset;
        enum mlx4_zone_flags            flags;
};

struct mlx4_zone_allocator *mlx4_zone_allocator_create(enum mlx4_zone_alloc_flags flags)
{
        struct mlx4_zone_allocator *zones = kmalloc_obj(*zones);

        if (NULL == zones)
                return NULL;

        INIT_LIST_HEAD(&zones->entries);
        INIT_LIST_HEAD(&zones->prios);
        spin_lock_init(&zones->lock);
        zones->last_uid = 0;
        zones->mask = 0;
        zones->flags = flags;

        return zones;
}

int mlx4_zone_add_one(struct mlx4_zone_allocator *zone_alloc,
                      struct mlx4_bitmap *bitmap,
                      u32 flags,
                      int priority,
                      int offset,
                      u32 *puid)
{
        u32 mask = mlx4_bitmap_masked_value(bitmap, (u32)-1);
        struct mlx4_zone_entry *it;
        struct mlx4_zone_entry *zone = kmalloc_obj(*zone);

        if (NULL == zone)
                return -ENOMEM;

        zone->flags = flags;
        zone->bitmap = bitmap;
        zone->use_rr = (flags & MLX4_ZONE_USE_RR) ? MLX4_USE_RR : 0;
        zone->priority = priority;
        zone->offset = offset;

        spin_lock(&zone_alloc->lock);

        zone->uid = zone_alloc->last_uid++;
        zone->allocator = zone_alloc;

        if (zone_alloc->mask < mask)
                zone_alloc->mask = mask;

        list_for_each_entry(it, &zone_alloc->prios, prio_list)
                if (it->priority >= priority)
                        break;

        if (&it->prio_list == &zone_alloc->prios || it->priority > priority)
                list_add_tail(&zone->prio_list, &it->prio_list);
        list_add_tail(&zone->list, &it->list);

        spin_unlock(&zone_alloc->lock);

        *puid = zone->uid;

        return 0;
}

/* Should be called under a lock */
static void __mlx4_zone_remove_one_entry(struct mlx4_zone_entry *entry)
{
        struct mlx4_zone_allocator *zone_alloc = entry->allocator;

        if (!list_empty(&entry->prio_list)) {
                /* Check if we need to add an alternative node to the prio list */
                if (!list_is_last(&entry->list, &zone_alloc->entries)) {
                        struct mlx4_zone_entry *next = list_first_entry(&entry->list,
                                                                        typeof(*next),
                                                                        list);

                        if (next->priority == entry->priority)
                                list_add_tail(&next->prio_list, &entry->prio_list);
                }

                list_del(&entry->prio_list);
        }

        list_del(&entry->list);

        if (zone_alloc->flags & MLX4_ZONE_ALLOC_FLAGS_NO_OVERLAP) {
                u32 mask = 0;
                struct mlx4_zone_entry *it;

                list_for_each_entry(it, &zone_alloc->prios, prio_list) {
                        u32 cur_mask = mlx4_bitmap_masked_value(it->bitmap, (u32)-1);

                        if (mask < cur_mask)
                                mask = cur_mask;
                }
                zone_alloc->mask = mask;
        }
}

void mlx4_zone_allocator_destroy(struct mlx4_zone_allocator *zone_alloc)
{
        struct mlx4_zone_entry *zone, *tmp;

        spin_lock(&zone_alloc->lock);

        list_for_each_entry_safe(zone, tmp, &zone_alloc->entries, list) {
                list_del(&zone->list);
                list_del(&zone->prio_list);
                kfree(zone);
        }

        spin_unlock(&zone_alloc->lock);
        kfree(zone_alloc);
}

/* Should be called under a lock */
static u32 __mlx4_alloc_from_zone(struct mlx4_zone_entry *zone, int count,
                                  int align, u32 skip_mask, u32 *puid)
{
        u32 uid = 0;
        u32 res;
        struct mlx4_zone_allocator *zone_alloc = zone->allocator;
        struct mlx4_zone_entry *curr_node;

        res = mlx4_bitmap_alloc_range(zone->bitmap, count,
                                      align, skip_mask);

        if (res != (u32)-1) {
                res += zone->offset;
                uid = zone->uid;
                goto out;
        }

        list_for_each_entry(curr_node, &zone_alloc->prios, prio_list) {
                if (unlikely(curr_node->priority == zone->priority))
                        break;
        }

        if (zone->flags & MLX4_ZONE_ALLOW_ALLOC_FROM_LOWER_PRIO) {
                struct mlx4_zone_entry *it = curr_node;

                list_for_each_entry_continue_reverse(it, &zone_alloc->entries, list) {
                        res = mlx4_bitmap_alloc_range(it->bitmap, count,
                                                      align, skip_mask);
                        if (res != (u32)-1) {
                                res += it->offset;
                                uid = it->uid;
                                goto out;
                        }
                }
        }

        if (zone->flags & MLX4_ZONE_ALLOW_ALLOC_FROM_EQ_PRIO) {
                struct mlx4_zone_entry *it = curr_node;

                list_for_each_entry_from(it, &zone_alloc->entries, list) {
                        if (unlikely(it == zone))
                                continue;

                        if (unlikely(it->priority != curr_node->priority))
                                break;

                        res = mlx4_bitmap_alloc_range(it->bitmap, count,
                                                      align, skip_mask);
                        if (res != (u32)-1) {
                                res += it->offset;
                                uid = it->uid;
                                goto out;
                        }
                }
        }

        if (zone->flags & MLX4_ZONE_FALLBACK_TO_HIGHER_PRIO) {
                if (list_is_last(&curr_node->prio_list, &zone_alloc->prios))
                        goto out;

                curr_node = list_first_entry(&curr_node->prio_list,
                                             typeof(*curr_node),
                                             prio_list);

                list_for_each_entry_from(curr_node, &zone_alloc->entries, list) {
                        res = mlx4_bitmap_alloc_range(curr_node->bitmap, count,
                                                      align, skip_mask);
                        if (res != (u32)-1) {
                                res += curr_node->offset;
                                uid = curr_node->uid;
                                goto out;
                        }
                }
        }

out:
        if (NULL != puid && res != (u32)-1)
                *puid = uid;
        return res;
}

/* Should be called under a lock */
static void __mlx4_free_from_zone(struct mlx4_zone_entry *zone, u32 obj,
                                  u32 count)
{
        mlx4_bitmap_free_range(zone->bitmap, obj - zone->offset, count, zone->use_rr);
}

/* Should be called under a lock */
static struct mlx4_zone_entry *__mlx4_find_zone_by_uid(
                struct mlx4_zone_allocator *zones, u32 uid)
{
        struct mlx4_zone_entry *zone;

        list_for_each_entry(zone, &zones->entries, list) {
                if (zone->uid == uid)
                        return zone;
        }

        return NULL;
}

struct mlx4_bitmap *mlx4_zone_get_bitmap(struct mlx4_zone_allocator *zones, u32 uid)
{
        struct mlx4_zone_entry *zone;
        struct mlx4_bitmap *bitmap;

        spin_lock(&zones->lock);

        zone = __mlx4_find_zone_by_uid(zones, uid);

        bitmap = zone == NULL ? NULL : zone->bitmap;

        spin_unlock(&zones->lock);

        return bitmap;
}

int mlx4_zone_remove_one(struct mlx4_zone_allocator *zones, u32 uid)
{
        struct mlx4_zone_entry *zone;
        int res = 0;

        spin_lock(&zones->lock);

        zone = __mlx4_find_zone_by_uid(zones, uid);

        if (NULL == zone) {
                res = -1;
                goto out;
        }

        __mlx4_zone_remove_one_entry(zone);

out:
        spin_unlock(&zones->lock);
        kfree(zone);

        return res;
}

/* Should be called under a lock */
static struct mlx4_zone_entry *__mlx4_find_zone_by_uid_unique(
                struct mlx4_zone_allocator *zones, u32 obj)
{
        struct mlx4_zone_entry *zone, *zone_candidate = NULL;
        u32 dist = (u32)-1;

        /* Search for the smallest zone that this obj could be
         * allocated from. This is done in order to handle
         * situations when small bitmaps are allocated from bigger
         * bitmaps (and the allocated space is marked as reserved in
         * the bigger bitmap.
         */
        list_for_each_entry(zone, &zones->entries, list) {
                if (obj >= zone->offset) {
                        u32 mobj = (obj - zone->offset) & zones->mask;

                        if (mobj < zone->bitmap->max) {
                                u32 curr_dist = zone->bitmap->effective_len;

                                if (curr_dist < dist) {
                                        dist = curr_dist;
                                        zone_candidate = zone;
                                }
                        }
                }
        }

        return zone_candidate;
}

u32 mlx4_zone_alloc_entries(struct mlx4_zone_allocator *zones, u32 uid, int count,
                            int align, u32 skip_mask, u32 *puid)
{
        struct mlx4_zone_entry *zone;
        int res = -1;

        spin_lock(&zones->lock);

        zone = __mlx4_find_zone_by_uid(zones, uid);

        if (NULL == zone)
                goto out;

        res = __mlx4_alloc_from_zone(zone, count, align, skip_mask, puid);

out:
        spin_unlock(&zones->lock);

        return res;
}

u32 mlx4_zone_free_entries_unique(struct mlx4_zone_allocator *zones, u32 obj, u32 count)
{
        struct mlx4_zone_entry *zone;
        int res;

        if (!(zones->flags & MLX4_ZONE_ALLOC_FLAGS_NO_OVERLAP))
                return -EFAULT;

        spin_lock(&zones->lock);

        zone = __mlx4_find_zone_by_uid_unique(zones, obj);

        if (NULL == zone) {
                res = -1;
                goto out;
        }

        __mlx4_free_from_zone(zone, obj, count);
        res = 0;

out:
        spin_unlock(&zones->lock);

        return res;
}

static int mlx4_buf_direct_alloc(struct mlx4_dev *dev, int size,
                                 struct mlx4_buf *buf)
{
        dma_addr_t t;

        buf->nbufs        = 1;
        buf->npages       = 1;
        buf->page_shift   = get_order(size) + PAGE_SHIFT;
        buf->direct.buf   =
                dma_alloc_coherent(&dev->persist->pdev->dev, size, &t,
                                   GFP_KERNEL);
        if (!buf->direct.buf)
                return -ENOMEM;

        buf->direct.map = t;

        while (t & ((1 << buf->page_shift) - 1)) {
                --buf->page_shift;
                buf->npages *= 2;
        }

        return 0;
}

/* Handling for queue buffers -- we allocate a bunch of memory and
 * register it in a memory region at HCA virtual address 0. If the
 *  requested size is > max_direct, we split the allocation into
 *  multiple pages, so we don't require too much contiguous memory.
 */
int mlx4_buf_alloc(struct mlx4_dev *dev, int size, int max_direct,
                   struct mlx4_buf *buf)
{
        if (size <= max_direct) {
                return mlx4_buf_direct_alloc(dev, size, buf);
        } else {
                dma_addr_t t;
                int i;

                buf->direct.buf = NULL;
                buf->nbufs      = DIV_ROUND_UP(size, PAGE_SIZE);
                buf->npages     = buf->nbufs;
                buf->page_shift  = PAGE_SHIFT;
                buf->page_list   = kzalloc_objs(*buf->page_list, buf->nbufs);
                if (!buf->page_list)
                        return -ENOMEM;

                for (i = 0; i < buf->nbufs; ++i) {
                        buf->page_list[i].buf =
                                dma_alloc_coherent(&dev->persist->pdev->dev,
                                                   PAGE_SIZE, &t, GFP_KERNEL);
                        if (!buf->page_list[i].buf)
                                goto err_free;

                        buf->page_list[i].map = t;
                }
        }

        return 0;

err_free:
        mlx4_buf_free(dev, size, buf);

        return -ENOMEM;
}
EXPORT_SYMBOL_GPL(mlx4_buf_alloc);

void mlx4_buf_free(struct mlx4_dev *dev, int size, struct mlx4_buf *buf)
{
        if (buf->nbufs == 1) {
                dma_free_coherent(&dev->persist->pdev->dev, size,
                                  buf->direct.buf, buf->direct.map);
        } else {
                int i;

                for (i = 0; i < buf->nbufs; ++i)
                        if (buf->page_list[i].buf)
                                dma_free_coherent(&dev->persist->pdev->dev,
                                                  PAGE_SIZE,
                                                  buf->page_list[i].buf,
                                                  buf->page_list[i].map);
                kfree(buf->page_list);
        }
}
EXPORT_SYMBOL_GPL(mlx4_buf_free);

static struct mlx4_db_pgdir *mlx4_alloc_db_pgdir(struct device *dma_device)
{
        struct mlx4_db_pgdir *pgdir;

        pgdir = kzalloc_obj(*pgdir);
        if (!pgdir)
                return NULL;

        bitmap_fill(pgdir->order1, MLX4_DB_PER_PAGE / 2);
        pgdir->bits[0] = pgdir->order0;
        pgdir->bits[1] = pgdir->order1;
        pgdir->db_page = dma_alloc_coherent(dma_device, PAGE_SIZE,
                                            &pgdir->db_dma, GFP_KERNEL);
        if (!pgdir->db_page) {
                kfree(pgdir);
                return NULL;
        }

        return pgdir;
}

static int mlx4_alloc_db_from_pgdir(struct mlx4_db_pgdir *pgdir,
                                    struct mlx4_db *db, unsigned int order)
{
        unsigned int o;
        int i;

        for (o = order; o <= 1; ++o) {
                i = find_first_bit(pgdir->bits[o], MLX4_DB_PER_PAGE >> o);
                if (i < MLX4_DB_PER_PAGE >> o)
                        goto found;
        }

        return -ENOMEM;

found:
        clear_bit(i, pgdir->bits[o]);

        i <<= o;

        if (o > order)
                set_bit(i ^ 1, pgdir->bits[order]);

        db->u.pgdir = pgdir;
        db->index   = i;
        db->db      = pgdir->db_page + db->index;
        db->dma     = pgdir->db_dma  + db->index * 4;
        db->order   = order;

        return 0;
}

int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, unsigned int order)
{
        struct mlx4_priv *priv = mlx4_priv(dev);
        struct mlx4_db_pgdir *pgdir;
        int ret = 0;

        mutex_lock(&priv->pgdir_mutex);

        list_for_each_entry(pgdir, &priv->pgdir_list, list)
                if (!mlx4_alloc_db_from_pgdir(pgdir, db, order))
                        goto out;

        pgdir = mlx4_alloc_db_pgdir(&dev->persist->pdev->dev);
        if (!pgdir) {
                ret = -ENOMEM;
                goto out;
        }

        list_add(&pgdir->list, &priv->pgdir_list);

        /* This should never fail -- we just allocated an empty page: */
        WARN_ON(mlx4_alloc_db_from_pgdir(pgdir, db, order));

out:
        mutex_unlock(&priv->pgdir_mutex);

        return ret;
}
EXPORT_SYMBOL_GPL(mlx4_db_alloc);

void mlx4_db_free(struct mlx4_dev *dev, struct mlx4_db *db)
{
        struct mlx4_priv *priv = mlx4_priv(dev);
        int o;
        int i;

        mutex_lock(&priv->pgdir_mutex);

        o = db->order;
        i = db->index;

        if (db->order == 0 && test_bit(i ^ 1, db->u.pgdir->order0)) {
                clear_bit(i ^ 1, db->u.pgdir->order0);
                ++o;
        }
        i >>= o;
        set_bit(i, db->u.pgdir->bits[o]);

        if (bitmap_full(db->u.pgdir->order1, MLX4_DB_PER_PAGE / 2)) {
                dma_free_coherent(&dev->persist->pdev->dev, PAGE_SIZE,
                                  db->u.pgdir->db_page, db->u.pgdir->db_dma);
                list_del(&db->u.pgdir->list);
                kfree(db->u.pgdir);
        }

        mutex_unlock(&priv->pgdir_mutex);
}
EXPORT_SYMBOL_GPL(mlx4_db_free);

int mlx4_alloc_hwq_res(struct mlx4_dev *dev, struct mlx4_hwq_resources *wqres,
                       int size)
{
        int err;

        err = mlx4_db_alloc(dev, &wqres->db, 1);
        if (err)
                return err;

        *wqres->db.db = 0;

        err = mlx4_buf_direct_alloc(dev, size, &wqres->buf);
        if (err)
                goto err_db;

        err = mlx4_mtt_init(dev, wqres->buf.npages, wqres->buf.page_shift,
                            &wqres->mtt);
        if (err)
                goto err_buf;

        err = mlx4_buf_write_mtt(dev, &wqres->mtt, &wqres->buf);
        if (err)
                goto err_mtt;

        return 0;

err_mtt:
        mlx4_mtt_cleanup(dev, &wqres->mtt);
err_buf:
        mlx4_buf_free(dev, size, &wqres->buf);
err_db:
        mlx4_db_free(dev, &wqres->db);

        return err;
}
EXPORT_SYMBOL_GPL(mlx4_alloc_hwq_res);

void mlx4_free_hwq_res(struct mlx4_dev *dev, struct mlx4_hwq_resources *wqres,
                       int size)
{
        mlx4_mtt_cleanup(dev, &wqres->mtt);
        mlx4_buf_free(dev, size, &wqres->buf);
        mlx4_db_free(dev, &wqres->db);
}
EXPORT_SYMBOL_GPL(mlx4_free_hwq_res);