[net-next-2.6.git] / drivers / net / enic / cq_desc.h

/*
 * Copyright 2008-2010 Cisco Systems, Inc.  All rights reserved.
 * Copyright 2007 Nuova Systems, Inc.  All rights reserved.
 *
 * This program is free software; you may redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * 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.
 *
 */

#ifndef _CQ_DESC_H_
#define _CQ_DESC_H_

/*
 * Completion queue descriptor types
 */
enum cq_desc_types {
	CQ_DESC_TYPE_WQ_ENET = 0,
	CQ_DESC_TYPE_DESC_COPY = 1,
	CQ_DESC_TYPE_WQ_EXCH = 2,
	CQ_DESC_TYPE_RQ_ENET = 3,
	CQ_DESC_TYPE_RQ_FCP = 4,
};

/* Completion queue descriptor: 16B
 *
 * All completion queues have this basic layout.  The
 * type_specfic area is unique for each completion
 * queue type.
 */
struct cq_desc {
	__le16 completed_index;
	__le16 q_number;
	u8 type_specfic[11];
	u8 type_color;
};

#define CQ_DESC_TYPE_BITS        4
#define CQ_DESC_TYPE_MASK        ((1 << CQ_DESC_TYPE_BITS) - 1)
#define CQ_DESC_COLOR_MASK       1
#define CQ_DESC_COLOR_SHIFT      7
#define CQ_DESC_Q_NUM_BITS       10
#define CQ_DESC_Q_NUM_MASK       ((1 << CQ_DESC_Q_NUM_BITS) - 1)
#define CQ_DESC_COMP_NDX_BITS    12
#define CQ_DESC_COMP_NDX_MASK    ((1 << CQ_DESC_COMP_NDX_BITS) - 1)

static inline void cq_desc_dec(const struct cq_desc *desc_arg,
	u8 *type, u8 *color, u16 *q_number, u16 *completed_index)
{
	const struct cq_desc *desc = desc_arg;
	const u8 type_color = desc->type_color;

	*color = (type_color >> CQ_DESC_COLOR_SHIFT) & CQ_DESC_COLOR_MASK;

	/*
	 * Make sure color bit is read from desc *before* other fields
	 * are read from desc.  Hardware guarantees color bit is last
	 * bit (byte) written.  Adding the rmb() prevents the compiler
	 * and/or CPU from reordering the reads which would potentially
	 * result in reading stale values.
	 */

	rmb();

	*type = type_color & CQ_DESC_TYPE_MASK;
	*q_number = le16_to_cpu(desc->q_number) & CQ_DESC_Q_NUM_MASK;
	*completed_index = le16_to_cpu(desc->completed_index) &
		CQ_DESC_COMP_NDX_MASK;
}

#endif /* _CQ_DESC_H_ */
Commit	Line	Data
01f2e4ea	1	/*
29046f9b	2	* Copyright 2008-2010 Cisco Systems, Inc. All rights reserved.
01f2e4ea SF	3	* Copyright 2007 Nuova Systems, Inc. All rights reserved.
	4	*
	5	* This program is free software; you may redistribute it and/or modify
	6	* it under the terms of the GNU General Public License as published by
	7	* the Free Software Foundation; version 2 of the License.
	8	*
	9	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	10	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	11	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	12	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
	13	* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
	14	* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	15	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	16	* SOFTWARE.
	17	*
	18	*/
	19
	20	#ifndef _CQ_DESC_H_
	21	#define _CQ_DESC_H_
	22
	23	/*
	24	* Completion queue descriptor types
	25	*/
	26	enum cq_desc_types {
	27	CQ_DESC_TYPE_WQ_ENET = 0,
	28	CQ_DESC_TYPE_DESC_COPY = 1,
	29	CQ_DESC_TYPE_WQ_EXCH = 2,
	30	CQ_DESC_TYPE_RQ_ENET = 3,
	31	CQ_DESC_TYPE_RQ_FCP = 4,
	32	};
	33
	34	/* Completion queue descriptor: 16B
	35	*
	36	* All completion queues have this basic layout. The
	37	* type_specfic area is unique for each completion
	38	* queue type.
	39	*/
	40	struct cq_desc {
	41	__le16 completed_index;
	42	__le16 q_number;
	43	u8 type_specfic[11];
	44	u8 type_color;
	45	};
	46
cb3c7669	47	#define CQ_DESC_TYPE_BITS 4
01f2e4ea SF	48	#define CQ_DESC_TYPE_MASK ((1 << CQ_DESC_TYPE_BITS) - 1)
01f2e4ea SF	49	#define CQ_DESC_COLOR_MASK 1
cb3c7669	50	#define CQ_DESC_COLOR_SHIFT 7
01f2e4ea SF	51	#define CQ_DESC_Q_NUM_BITS 10
	52	#define CQ_DESC_Q_NUM_MASK ((1 << CQ_DESC_Q_NUM_BITS) - 1)
	53	#define CQ_DESC_COMP_NDX_BITS 12
	54	#define CQ_DESC_COMP_NDX_MASK ((1 << CQ_DESC_COMP_NDX_BITS) - 1)
	55
	56	static inline void cq_desc_dec(const struct cq_desc *desc_arg,
	57	u8 type, u8 color, u16 q_number, u16 completed_index)
	58	{
	59	const struct cq_desc *desc = desc_arg;
	60	const u8 type_color = desc->type_color;
	61
cb3c7669	62	*color = (type_color >> CQ_DESC_COLOR_SHIFT) & CQ_DESC_COLOR_MASK;
01f2e4ea SF	63
	64	/*
	65	* Make sure color bit is read from desc before other fields
	66	* are read from desc. Hardware guarantees color bit is last
	67	* bit (byte) written. Adding the rmb() prevents the compiler
	68	* and/or CPU from reordering the reads which would potentially
	69	* result in reading stale values.
	70	*/
	71
	72	rmb();
	73
	74	*type = type_color & CQ_DESC_TYPE_MASK;
	75	*q_number = le16_to_cpu(desc->q_number) & CQ_DESC_Q_NUM_MASK;
	76	*completed_index = le16_to_cpu(desc->completed_index) &
	77	CQ_DESC_COMP_NDX_MASK;
	78	}
	79
	80	#endif /* _CQ_DESC_H_ */