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	This patch refactors the IB core umem code and vendor drivers to use a linear (chained) SG table instead of chunk list. With this change the relevant code becomes clearer—no need for nested loops to build and use umem. Signed-off-by: Shachar Raindel <raindel@mellanox.com> Signed-off-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
		
			
				
	
	
		
			96 lines
		
	
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			96 lines
		
	
	
	
		
			2.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright (c) 2007 Cisco Systems, Inc. All rights reserved.
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 *
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 * This software is available to you under a choice of one of two
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 * licenses.  You may choose to be licensed under the terms of the GNU
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 * General Public License (GPL) Version 2, available from the file
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 * COPYING in the main directory of this source tree, or the
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 * OpenIB.org BSD license below:
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 *
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 *     Redistribution and use in source and binary forms, with or
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 *     without modification, are permitted provided that the following
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 *     conditions are met:
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 *
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 *      - Redistributions of source code must retain the above
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 *        copyright notice, this list of conditions and the following
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 *        disclaimer.
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 *
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 *      - Redistributions in binary form must reproduce the above
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 *        copyright notice, this list of conditions and the following
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 *        disclaimer in the documentation and/or other materials
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 *        provided with the distribution.
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 *
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 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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 * SOFTWARE.
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 */
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#include <linux/slab.h>
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#include "mlx4_ib.h"
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struct mlx4_ib_user_db_page {
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	struct list_head	list;
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	struct ib_umem	       *umem;
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	unsigned long		user_virt;
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	int			refcnt;
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};
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int mlx4_ib_db_map_user(struct mlx4_ib_ucontext *context, unsigned long virt,
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			struct mlx4_db *db)
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{
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	struct mlx4_ib_user_db_page *page;
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	int err = 0;
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	mutex_lock(&context->db_page_mutex);
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	list_for_each_entry(page, &context->db_page_list, list)
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		if (page->user_virt == (virt & PAGE_MASK))
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			goto found;
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	page = kmalloc(sizeof *page, GFP_KERNEL);
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	if (!page) {
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		err = -ENOMEM;
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		goto out;
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	}
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	page->user_virt = (virt & PAGE_MASK);
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	page->refcnt    = 0;
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	page->umem      = ib_umem_get(&context->ibucontext, virt & PAGE_MASK,
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				      PAGE_SIZE, 0, 0);
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	if (IS_ERR(page->umem)) {
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		err = PTR_ERR(page->umem);
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		kfree(page);
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		goto out;
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	}
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	list_add(&page->list, &context->db_page_list);
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found:
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	db->dma = sg_dma_address(page->umem->sg_head.sgl) + (virt & ~PAGE_MASK);
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	db->u.user_page = page;
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	++page->refcnt;
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out:
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	mutex_unlock(&context->db_page_mutex);
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	return err;
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}
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void mlx4_ib_db_unmap_user(struct mlx4_ib_ucontext *context, struct mlx4_db *db)
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{
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	mutex_lock(&context->db_page_mutex);
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	if (!--db->u.user_page->refcnt) {
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		list_del(&db->u.user_page->list);
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		ib_umem_release(db->u.user_page->umem);
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		kfree(db->u.user_page);
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	}
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	mutex_unlock(&context->db_page_mutex);
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}
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