text: /*
   * 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/mlx5/driver.h>
  
  #include "mlx5_core.h"
  
  struct mlx5_db_pgdir {
  	struct list_head	list;
  	unsigned long	       *bitmap;
  	__be32		       *db_page;
  	dma_addr_t		db_dma;
  };
  
  /* 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 mlx5_priv *priv = &dev->priv;
  	int original_node;
  	void *cpu_handle;
  
  	mutex_lock(&priv->alloc_mutex);
  	original_node = dev_to_node(&dev->pdev->dev);
  	set_dev_node(&dev->pdev->dev, node);
  	cpu_handle = dma_zalloc_coherent(&dev->pdev->dev, size,
  					 dma_handle, GFP_KERNEL);
  	set_dev_node(&dev->pdev->dev, original_node);
  	mutex_unlock(&priv->alloc_mutex);
  	return cpu_handle;
  }
  
  int mlx5_buf_alloc_node(struct mlx5_core_dev *dev, int size,
  			struct mlx5_buf *buf, int node)
  {
  	dma_addr_t t;
  
  	buf->size = size;
  	buf->npages       = 1;
  	buf->page_shift   = (u8)get_order(size) + PAGE_SHIFT;
  	buf->direct.buf   = mlx5_dma_zalloc_coherent_node(dev, size,
  							  &t, node);
  	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;
  }
  
  int mlx5_buf_alloc(struct mlx5_core_dev *dev, int size, struct mlx5_buf *buf)
  {
  	return mlx5_buf_alloc_node(dev, size, buf, dev->priv.numa_node);
  }
  EXPORT_SYMBOL_GPL(mlx5_buf_alloc);
  
  void mlx5_buf_free(struct mlx5_core_dev *dev, struct mlx5_buf *buf)
  {
  	dma_free_coherent(&dev->pdev->dev, buf->size, buf->direct.buf,
  			  buf->direct.map);
  }
  EXPORT_SYMBOL_GPL(mlx5_buf_free);
  
  int mlx5_frag_buf_alloc_node(struct mlx5_core_dev *dev, int size,
  			     struct mlx5_frag_buf *buf, int node)
  {
  	int i;
  
  	buf->size = size;
  	buf->npages = 1 << get_order(size);
  	buf->page_shift = PAGE_SHIFT;
  	buf->frags = kcalloc(buf->npages, sizeof(struct mlx5_buf_list),
  			     GFP_KERNEL);
  	if (!buf->frags)
  		goto err_out;
  
  	for (i = 0; i < buf->npages; i++) {
  		struct mlx5_buf_list *frag = &buf->frags[i];
  		int frag_sz = min_t(int, size, PAGE_SIZE);
  
  		frag->buf = mlx5_dma_zalloc_coherent_node(dev, frag_sz,
  							  &frag->map, node);
  		if (!frag->buf)
  			goto err_free_buf;
  		if (frag->map & ((1 << buf->page_shift) - 1)) {
  			dma_free_coherent(&dev->pdev->dev, frag_sz,
  					  buf->frags[i].buf, buf->frags[i].map);
  			mlx5_core_warn(dev, "unexpected map alignment: %pad, page_shift=%d\n",
  				       &frag->map, buf->page_shift);
  			goto err_free_buf;
  		}
  		size -= frag_sz;
  	}
  
  	return 0;
  
  err_free_buf:
  	while (i--)
  		dma_free_coherent(&dev->pdev->dev, PAGE_SIZE, buf->frags[i].buf,
  				  buf->frags[i].map);
  	kfree(buf->frags);
  err_out:
  	return -ENOMEM;
  }
  
  void mlx5_frag_buf_free(struct mlx5_core_dev *dev, struct mlx5_frag_buf *buf)
  {
  	int size = buf->size;
  	int i;
  
  	for (i = 0; i < buf->npages; i++) {
  		int frag_sz = min_t(int, size, PAGE_SIZE);
  
  		dma_free_coherent(&dev->pdev->dev, frag_sz, buf->frags[i].buf,
  				  buf->frags[i].map);
  		size -= frag_sz;
  	}
  	kfree(buf->frags);
  }
  
  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(sizeof(*pgdir), GFP_KERNEL);
  	if (!pgdir)
  		return NULL;
  
  	pgdir->bitmap = kcalloc(BITS_TO_LONGS(db_per_page),
  				sizeof(unsigned long),
  				GFP_KERNEL);
  
  	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) {
  		kfree(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);
  
  int mlx5_db_alloc(struct mlx5_core_dev *dev, struct mlx5_db *db)
  {
  	return mlx5_db_alloc_node(dev, db, dev->priv.numa_node);
  }
  EXPORT_SYMBOL_GPL(mlx5_db_alloc);
  
  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(&(dev->pdev->dev), PAGE_SIZE,
  				  db->u.pgdir->db_page, db->u.pgdir->db_dma);
  		list_del(&db->u.pgdir->list);
  		kfree(db->u.pgdir->bitmap);
  		kfree(db->u.pgdir);
  	}
  
  	mutex_unlock(&dev->priv.pgdir_mutex);
  }
  EXPORT_SYMBOL_GPL(mlx5_db_free);
  
  
  void mlx5_fill_page_array(struct mlx5_buf *buf, __be64 *pas)
  {
  	u64 addr;
  	int i;
  
  	for (i = 0; i < buf->npages; i++) {
  		addr = buf->direct.map + (i << buf->page_shift);
  
  		pas[i] = cpu_to_be64(addr);
  	}
  }
  EXPORT_SYMBOL_GPL(mlx5_fill_page_array);
  
  void mlx5_fill_page_frag_array(struct mlx5_frag_buf *buf, __be64 *pas)
  {
  	int i;
  
  	for (i = 0; i < buf->npages; i++)
  		pas[i] = cpu_to_be64(buf->frags[i].map);
  }
  EXPORT_SYMBOL_GPL(mlx5_fill_page_frag_array);
  