/*
 * Copyright (c) 2013-2015, 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 <linux/nodemask.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/mlx5/driver.h>

#include "mlx5_core.h"

#define MLX5_FRAG_BUF_POOL_MIN_BLOCK_SHIFT      MLX5_ADAPTER_PAGE_SHIFT
#define MLX5_FRAG_BUF_POOLS_NUM \
        (PAGE_SHIFT - MLX5_FRAG_BUF_POOL_MIN_BLOCK_SHIFT + 1)

struct mlx5_db_pgdir {
        struct list_head        list;
        unsigned long          *bitmap;
        __be32                 *db_page;
        dma_addr_t              db_dma;
};

struct mlx5_dma_pool {
        /* Protects page_list and per-page allocation bitmaps. */
        struct mutex lock;
        struct list_head page_list;
        struct mlx5_core_dev *dev;
        int node;
        u8 block_shift;
};

struct mlx5_dma_pool_page {
        struct mlx5_dma_pool *pool;
        struct list_head pool_link;
        unsigned long *bitmap;
        void *buf;
        dma_addr_t dma;
};

struct mlx5_frag_buf_node_pools {
        struct mlx5_dma_pool *pools[MLX5_FRAG_BUF_POOLS_NUM];
};

struct mlx5_dma_pool_stats {
        int node;
        size_t block_size;
        size_t used_blocks;
        size_t allocated_blocks;
};

/* Handling for queue buffers -- we allocate a bunch of memory and
 * register it in a memory region at HCA virtual address 0.
 */

static void *mlx5_dma_zalloc_coherent_node(struct mlx5_core_dev *dev,
                                           size_t size, dma_addr_t *dma_handle,
                                           int node)
{
        struct device *device = mlx5_core_dma_dev(dev);
        struct mlx5_priv *priv = &dev->priv;
        int original_node;
        void *cpu_handle;

        mutex_lock(&priv->alloc_mutex);
        original_node = dev_to_node(device);
        set_dev_node(device, node);
        cpu_handle = dma_alloc_coherent(device, size, dma_handle,
                                        GFP_KERNEL);
        set_dev_node(device, original_node);
        mutex_unlock(&priv->alloc_mutex);
        return cpu_handle;
}

static void mlx5_dma_pool_destroy(struct mlx5_dma_pool *pool)
{
        mutex_destroy(&pool->lock);
        kfree(pool);
}

static struct mlx5_dma_pool *mlx5_dma_pool_create(struct mlx5_core_dev *dev,
                                                  int node, u8 block_shift)
{
        struct mlx5_dma_pool *pool;

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

        INIT_LIST_HEAD(&pool->page_list);
        mutex_init(&pool->lock);
        pool->dev = dev;
        pool->node = node;
        pool->block_shift = block_shift;
        return pool;
}

static struct mlx5_dma_pool_page *
mlx5_dma_pool_page_alloc(struct mlx5_dma_pool *pool)
{
        int blocks_per_page = BIT(PAGE_SHIFT - pool->block_shift);
        struct mlx5_dma_pool_page *page;

        page = kzalloc_obj(*page);
        if (!page)
                goto err_out;

        page->pool = pool;
        page->bitmap = bitmap_zalloc(blocks_per_page, GFP_KERNEL);
        if (!page->bitmap)
                goto err_free_page;

        bitmap_fill(page->bitmap, blocks_per_page);
        page->buf = mlx5_dma_zalloc_coherent_node(pool->dev, PAGE_SIZE,
                                                  &page->dma, pool->node);
        if (!page->buf)
                goto err_free_bitmap;

        return page;

err_free_bitmap:
        bitmap_free(page->bitmap);
err_free_page:
        kfree(page);
err_out:
        return NULL;
}

static void mlx5_dma_pool_page_free(struct mlx5_core_dev *dev,
                                    struct mlx5_dma_pool_page *page)
{
        dma_free_coherent(mlx5_core_dma_dev(dev), PAGE_SIZE, page->buf,
                          page->dma);
        bitmap_free(page->bitmap);
        kfree(page);
}

static int mlx5_dma_pool_alloc_from_page(struct mlx5_dma_pool *pool,
                                         struct mlx5_dma_pool_page *page,
                                         unsigned long *idx_out)
{
        int blocks_per_page = BIT(PAGE_SHIFT - pool->block_shift);

        *idx_out = find_first_bit(page->bitmap, blocks_per_page);
        if (*idx_out >= blocks_per_page)
                return -ENOMEM;

        __clear_bit(*idx_out, page->bitmap);

        if (bitmap_empty(page->bitmap, blocks_per_page))
                list_move_tail(&page->pool_link, &pool->page_list);

        return 0;
}

static struct mlx5_dma_pool_page *
mlx5_dma_pool_alloc(struct mlx5_dma_pool *pool, unsigned long *idx_out)
{
        struct mlx5_dma_pool_page *page;

        mutex_lock(&pool->lock);

        page = list_first_entry_or_null(&pool->page_list,
                                        struct mlx5_dma_pool_page, pool_link);
        if (page && !mlx5_dma_pool_alloc_from_page(pool, page, idx_out))
                goto unlock; /* successfully allocated from existing page */

        page = mlx5_dma_pool_page_alloc(pool);
        if (!page)
                goto unlock;

        list_add(&page->pool_link, &pool->page_list);
        mlx5_dma_pool_alloc_from_page(pool, page, idx_out);

unlock:
        mutex_unlock(&pool->lock);
        return page;
}

static void mlx5_dma_pool_free(struct mlx5_dma_pool *pool,
                               struct mlx5_dma_pool_page *page,
                               unsigned long idx)
{
        int blocks_per_page = BIT(PAGE_SHIFT - pool->block_shift);
        bool was_full;

        mutex_lock(&pool->lock);
        was_full = bitmap_empty(page->bitmap, blocks_per_page);
        __set_bit(idx, page->bitmap);

        if (bitmap_full(page->bitmap, blocks_per_page)) {
                list_del(&page->pool_link);
                mlx5_dma_pool_page_free(pool->dev, page);
        } else {
                memset((u8 *)page->buf + (idx << pool->block_shift), 0,
                       BIT(pool->block_shift));
                if (was_full)
                        list_move(&page->pool_link, &pool->page_list);
        }
        mutex_unlock(&pool->lock);
}

static void mlx5_dma_pool_debugfs_get_stats(struct mlx5_dma_pool *pool,
                                            struct mlx5_dma_pool_stats *stats)
{
        int blocks_per_page = BIT(PAGE_SHIFT - pool->block_shift);
        struct mlx5_dma_pool_page *page;
        size_t free_blocks = 0;
        size_t pages = 0;

        mutex_lock(&pool->lock);
        list_for_each_entry(page, &pool->page_list, pool_link) {
                pages++;
                free_blocks += bitmap_weight(page->bitmap, blocks_per_page);
        }
        mutex_unlock(&pool->lock);

        stats->node = pool->node;
        stats->block_size = BIT(pool->block_shift);
        stats->allocated_blocks = pages * blocks_per_page;
        stats->used_blocks = stats->allocated_blocks - free_blocks;
}

static void mlx5_dma_pool_debugfs_stats_print(struct seq_file *file,
                                              struct mlx5_dma_pool *pool)
{
        struct mlx5_dma_pool_stats stats = {};

        mlx5_dma_pool_debugfs_get_stats(pool, &stats);
        seq_printf(file, "%4d       %5zu      %7zu           %7zu\n",
                   stats.node, stats.block_size, stats.used_blocks,
                   stats.allocated_blocks);
}

static void mlx5_dma_pools_debugfs_print_header(struct seq_file *file)
{
        seq_puts(file, "node  block_size  used_blocks  allocated_blocks\n");
}

static void
mlx5_frag_buf_node_pools_destroy(struct mlx5_frag_buf_node_pools *node_pools)
{
        for (int i = 0; i < MLX5_FRAG_BUF_POOLS_NUM; i++)
                if (node_pools->pools[i])
                        mlx5_dma_pool_destroy(node_pools->pools[i]);
        kfree(node_pools);
}

static struct mlx5_frag_buf_node_pools *
mlx5_frag_buf_node_pools_create(struct mlx5_core_dev *dev, int node)
{
        struct mlx5_frag_buf_node_pools *node_pools;

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

        for (int i = 0; i < MLX5_FRAG_BUF_POOLS_NUM; i++) {
                u8 block_shift = MLX5_FRAG_BUF_POOL_MIN_BLOCK_SHIFT + i;

                node_pools->pools[i] = mlx5_dma_pool_create(dev, node,
                                                            block_shift);
                if (!node_pools->pools[i]) {
                        mlx5_frag_buf_node_pools_destroy(node_pools);
                        return NULL;
                }
        }

        return node_pools;
}

static int
mlx5_frag_buf_dma_pools_debugfs_show(struct seq_file *file, void *priv)
{
        struct mlx5_core_dev *dev = file->private;
        int node;

        mlx5_dma_pools_debugfs_print_header(file);

        if (!dev->priv.frag_buf_node_pools)
                return 0;

        for_each_node_state(node, N_POSSIBLE) {
                struct mlx5_frag_buf_node_pools *node_pools;

                node_pools = dev->priv.frag_buf_node_pools[node];
                if (!node_pools)
                        continue;

                for (int i = 0; i < MLX5_FRAG_BUF_POOLS_NUM; i++) {
                        struct mlx5_dma_pool *pool = node_pools->pools[i];

                        if (!pool)
                                continue;

                        mlx5_dma_pool_debugfs_stats_print(file, pool);
                }
        }

        return 0;
}
DEFINE_SHOW_ATTRIBUTE(mlx5_frag_buf_dma_pools_debugfs);

void mlx5_frag_buf_pools_cleanup(struct mlx5_core_dev *dev)
{
        struct mlx5_priv *priv = &dev->priv;
        int node;

        debugfs_remove(priv->dbg.frag_buf_dma_pools_debugfs);
        priv->dbg.frag_buf_dma_pools_debugfs = NULL;

        for_each_node_state(node, N_POSSIBLE) {
                struct mlx5_frag_buf_node_pools *node_pools;

                node_pools = priv->frag_buf_node_pools[node];
                if (!node_pools)
                        continue;
                mlx5_frag_buf_node_pools_destroy(node_pools);
        }

        kfree(priv->frag_buf_node_pools);
        priv->frag_buf_node_pools = NULL;
}

int mlx5_frag_buf_pools_init(struct mlx5_core_dev *dev)
{
        struct mlx5_priv *priv = &dev->priv;
        int node;

        priv->frag_buf_node_pools = kzalloc_objs(*priv->frag_buf_node_pools,
                                                 nr_node_ids);
        if (!priv->frag_buf_node_pools)
                return -ENOMEM;

        for_each_node_state(node, N_POSSIBLE) {
                struct mlx5_frag_buf_node_pools *node_pools;

                node_pools = mlx5_frag_buf_node_pools_create(dev, node);
                if (!node_pools) {
                        mlx5_frag_buf_pools_cleanup(dev);
                        return -ENOMEM;
                }
                priv->frag_buf_node_pools[node] = node_pools;
        }

        priv->dbg.frag_buf_dma_pools_debugfs =
                debugfs_create_file("frag_buf_dma_pools", 0444,
                                    priv->dbg.dbg_root, dev,
                                    &mlx5_frag_buf_dma_pools_debugfs_fops);

        return 0;
}

int mlx5_frag_buf_alloc_node(struct mlx5_core_dev *dev, int size,
                             struct mlx5_frag_buf *buf, int node)
{
        struct mlx5_dma_pool *pool;
        int pool_idx;

        node = node == NUMA_NO_NODE ? numa_mem_id() : node;

        buf->size = size;
        buf->npages = DIV_ROUND_UP(size, PAGE_SIZE);
        buf->page_shift = clamp_t(int, order_base_2(size),
                                  MLX5_FRAG_BUF_POOL_MIN_BLOCK_SHIFT,
                                  PAGE_SHIFT);
        buf->frags = kcalloc_node(buf->npages, sizeof(*buf->frags),
                                  GFP_KERNEL, node);
        if (!buf->frags)
                return -ENOMEM;

        pool_idx = buf->page_shift - MLX5_FRAG_BUF_POOL_MIN_BLOCK_SHIFT;
        pool = dev->priv.frag_buf_node_pools[node]->pools[pool_idx];
        for (int i = 0; i < buf->npages; i++) {
                struct mlx5_buf_list *frag = &buf->frags[i];
                struct mlx5_dma_pool_page *page;
                unsigned long idx;

                page = mlx5_dma_pool_alloc(pool, &idx);
                if (!page) {
                        mlx5_frag_buf_free(dev, buf);
                        return -ENOMEM;
                }
                frag->buf = (u8 *)page->buf + (idx << pool->block_shift);
                frag->map = page->dma + (idx << pool->block_shift);
                frag->frag_page = page;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(mlx5_frag_buf_alloc_node);

void mlx5_frag_buf_free(struct mlx5_core_dev *dev, struct mlx5_frag_buf *buf)
{
        for (int i = 0; i < buf->npages; i++) {
                struct mlx5_buf_list *frag = &buf->frags[i];
                struct mlx5_dma_pool_page *page;
                struct mlx5_dma_pool *pool;
                unsigned long idx;

                if (!frag->buf)
                        continue;

                page = frag->frag_page;
                pool = page->pool;
                idx = (frag->map - page->dma) >> pool->block_shift;
                mlx5_dma_pool_free(pool, page, idx);
        }
        kfree(buf->frags);
}
EXPORT_SYMBOL_GPL(mlx5_frag_buf_free);

static struct mlx5_db_pgdir *mlx5_alloc_db_pgdir(struct mlx5_core_dev *dev,
                                                 int node)
{
        u32 db_per_page = PAGE_SIZE / cache_line_size();
        struct mlx5_db_pgdir *pgdir;

        pgdir = kzalloc_node(sizeof(*pgdir), GFP_KERNEL, node);
        if (!pgdir)
                return NULL;

        pgdir->bitmap = bitmap_zalloc_node(db_per_page, GFP_KERNEL, node);
        if (!pgdir->bitmap) {
                kfree(pgdir);
                return NULL;
        }

        bitmap_fill(pgdir->bitmap, db_per_page);

        pgdir->db_page = mlx5_dma_zalloc_coherent_node(dev, PAGE_SIZE,
                                                       &pgdir->db_dma, node);
        if (!pgdir->db_page) {
                bitmap_free(pgdir->bitmap);
                kfree(pgdir);
                return NULL;
        }

        return pgdir;
}

static int mlx5_alloc_db_from_pgdir(struct mlx5_db_pgdir *pgdir,
                                    struct mlx5_db *db)
{
        u32 db_per_page = PAGE_SIZE / cache_line_size();
        int offset;
        int i;

        i = find_first_bit(pgdir->bitmap, db_per_page);
        if (i >= db_per_page)
                return -ENOMEM;

        __clear_bit(i, pgdir->bitmap);

        db->u.pgdir = pgdir;
        db->index   = i;
        offset = db->index * cache_line_size();
        db->db      = pgdir->db_page + offset / sizeof(*pgdir->db_page);
        db->dma     = pgdir->db_dma  + offset;

        db->db[0] = 0;
        db->db[1] = 0;

        return 0;
}

int mlx5_db_alloc_node(struct mlx5_core_dev *dev, struct mlx5_db *db, int node)
{
        struct mlx5_db_pgdir *pgdir;
        int ret = 0;

        mutex_lock(&dev->priv.pgdir_mutex);

        list_for_each_entry(pgdir, &dev->priv.pgdir_list, list)
                if (!mlx5_alloc_db_from_pgdir(pgdir, db))
                        goto out;

        pgdir = mlx5_alloc_db_pgdir(dev, node);
        if (!pgdir) {
                ret = -ENOMEM;
                goto out;
        }

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

        /* This should never fail -- we just allocated an empty page: */
        WARN_ON(mlx5_alloc_db_from_pgdir(pgdir, db));

out:
        mutex_unlock(&dev->priv.pgdir_mutex);

        return ret;
}
EXPORT_SYMBOL_GPL(mlx5_db_alloc_node);

void mlx5_db_free(struct mlx5_core_dev *dev, struct mlx5_db *db)
{
        u32 db_per_page = PAGE_SIZE / cache_line_size();

        mutex_lock(&dev->priv.pgdir_mutex);

        __set_bit(db->index, db->u.pgdir->bitmap);

        if (bitmap_full(db->u.pgdir->bitmap, db_per_page)) {
                dma_free_coherent(mlx5_core_dma_dev(dev), PAGE_SIZE,
                                  db->u.pgdir->db_page, db->u.pgdir->db_dma);
                list_del(&db->u.pgdir->list);
                bitmap_free(db->u.pgdir->bitmap);
                kfree(db->u.pgdir);
        }

        mutex_unlock(&dev->priv.pgdir_mutex);
}
EXPORT_SYMBOL_GPL(mlx5_db_free);

void mlx5_fill_page_frag_array_perm(struct mlx5_frag_buf *buf, __be64 *pas, u8 perm)
{
        int i;

        WARN_ON(perm & 0xfc);
        for (i = 0; i < buf->npages; i++)
                pas[i] = cpu_to_be64(buf->frags[i].map | perm);
}
EXPORT_SYMBOL_GPL(mlx5_fill_page_frag_array_perm);

void mlx5_fill_page_frag_array(struct mlx5_frag_buf *buf, __be64 *pas)
{
        mlx5_fill_page_frag_array_perm(buf, pas, 0);
}
EXPORT_SYMBOL_GPL(mlx5_fill_page_frag_array);