[linux-2.6-block.git] / include / scsi / fc_frame.h

/*
 * Copyright(c) 2007 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Maintained at www.Open-FCoE.org
 */

#ifndef _FC_FRAME_H_
#define _FC_FRAME_H_

#include <linux/scatterlist.h>
#include <linux/skbuff.h>
#include <scsi/scsi_cmnd.h>

#include <scsi/fc/fc_fs.h>
#include <scsi/fc/fc_fcp.h>
#include <scsi/fc/fc_encaps.h>

#include <linux/if_ether.h>

/*
 * The fc_frame interface is used to pass frame data between functions.
 * The frame includes the data buffer, length, and SOF / EOF delimiter types.
 * A pointer to the port structure of the receiving port is also includeded.
 */

#define	FC_FRAME_HEADROOM	32	/* headroom for VLAN + FCoE headers */
#define	FC_FRAME_TAILROOM	8	/* trailer space for FCoE */

/* Max number of skb frags allowed, reserving one for fcoe_crc_eof page */
#define FC_FRAME_SG_LEN		(MAX_SKB_FRAGS - 1)

#define fp_skb(fp)	(&((fp)->skb))
#define fr_hdr(fp)	((fp)->skb.data)
#define fr_len(fp)	((fp)->skb.len)
#define fr_cb(fp)	((struct fcoe_rcv_info *)&((fp)->skb.cb[0]))
#define fr_dev(fp)	(fr_cb(fp)->fr_dev)
#define fr_seq(fp)	(fr_cb(fp)->fr_seq)
#define fr_sof(fp)	(fr_cb(fp)->fr_sof)
#define fr_eof(fp)	(fr_cb(fp)->fr_eof)
#define fr_flags(fp)	(fr_cb(fp)->fr_flags)
#define fr_max_payload(fp)	(fr_cb(fp)->fr_max_payload)
#define fr_fsp(fp)	(fr_cb(fp)->fr_fsp)
#define fr_crc(fp)	(fr_cb(fp)->fr_crc)

struct fc_frame {
	struct sk_buff skb;
};

struct fcoe_rcv_info {
	struct packet_type  *ptype;
	struct fc_lport	*fr_dev;	/* transport layer private pointer */
	struct fc_seq	*fr_seq;	/* for use with exchange manager */
	struct fc_fcp_pkt *fr_fsp;	/* for the corresponding fcp I/O */
	u32		fr_crc;
	u16		fr_max_payload;	/* max FC payload */
	enum fc_sof	fr_sof;		/* start of frame delimiter */
	enum fc_eof	fr_eof;		/* end of frame delimiter */
	u8		fr_flags;	/* flags - see below */
	u8		granted_mac[ETH_ALEN]; /* FCoE MAC address */
};


/*
 * Get fc_frame pointer for an skb that's already been imported.
 */
static inline struct fcoe_rcv_info *fcoe_dev_from_skb(const struct sk_buff *skb)
{
	BUILD_BUG_ON(sizeof(struct fcoe_rcv_info) > sizeof(skb->cb));
	return (struct fcoe_rcv_info *) skb->cb;
}

/*
 * fr_flags.
 */
#define	FCPHF_CRC_UNCHECKED	0x01	/* CRC not computed, still appended */

/*
 * Initialize a frame.
 * We don't do a complete memset here for performance reasons.
 * The caller must set fr_free, fr_hdr, fr_len, fr_sof, and fr_eof eventually.
 */
static inline void fc_frame_init(struct fc_frame *fp)
{
	fr_dev(fp) = NULL;
	fr_seq(fp) = NULL;
	fr_flags(fp) = 0;
}

struct fc_frame *fc_frame_alloc_fill(struct fc_lport *, size_t payload_len);
struct fc_frame *_fc_frame_alloc(size_t payload_len);

/*
 * Allocate fc_frame structure and buffer.  Set the initial length to
 * payload_size + sizeof (struct fc_frame_header).
 */
static inline struct fc_frame *fc_frame_alloc(struct fc_lport *dev, size_t len)
{
	struct fc_frame *fp;

	/*
	 * Note: Since len will often be a constant multiple of 4,
	 * this check will usually be evaluated and eliminated at compile time.
	 */
	if (len && len % 4)
		fp = fc_frame_alloc_fill(dev, len);
	else
		fp = _fc_frame_alloc(len);
	return fp;
}

/*
 * Free the fc_frame structure and buffer.
 */
static inline void fc_frame_free(struct fc_frame *fp)
{
	kfree_skb(fp_skb(fp));
}

static inline int fc_frame_is_linear(struct fc_frame *fp)
{
	return !skb_is_nonlinear(fp_skb(fp));
}

/*
 * Get frame header from message in fc_frame structure.
 * This hides a cast and provides a place to add some checking.
 */
static inline
struct fc_frame_header *fc_frame_header_get(const struct fc_frame *fp)
{
	WARN_ON(fr_len(fp) < sizeof(struct fc_frame_header));
	return (struct fc_frame_header *) fr_hdr(fp);
}

/*
 * Get frame payload from message in fc_frame structure.
 * This hides a cast and provides a place to add some checking.
 * The len parameter is the minimum length for the payload portion.
 * Returns NULL if the frame is too short.
 *
 * This assumes the interesting part of the payload is in the first part
 * of the buffer for received data.  This may not be appropriate to use for
 * buffers being transmitted.
 */
static inline void *fc_frame_payload_get(const struct fc_frame *fp,
					 size_t len)
{
	void *pp = NULL;

	if (fr_len(fp) >= sizeof(struct fc_frame_header) + len)
		pp = fc_frame_header_get(fp) + 1;
	return pp;
}

/*
 * Get frame payload opcode (first byte) from message in fc_frame structure.
 * This hides a cast and provides a place to add some checking. Return 0
 * if the frame has no payload.
 */
static inline u8 fc_frame_payload_op(const struct fc_frame *fp)
{
	u8 *cp;

	cp = fc_frame_payload_get(fp, sizeof(u8));
	if (!cp)
		return 0;
	return *cp;

}

/*
 * Get FC class from frame.
 */
static inline enum fc_class fc_frame_class(const struct fc_frame *fp)
{
	return fc_sof_class(fr_sof(fp));
}

/*
 * Check the CRC in a frame.
 * The CRC immediately follows the last data item *AFTER* the length.
 * The return value is zero if the CRC matches.
 */
u32 fc_frame_crc_check(struct fc_frame *);

static inline u8 fc_frame_rctl(const struct fc_frame *fp)
{
	return fc_frame_header_get(fp)->fh_r_ctl;
}

static inline bool fc_frame_is_cmd(const struct fc_frame *fp)
{
	return fc_frame_rctl(fp) == FC_RCTL_DD_UNSOL_CMD;
}

/*
 * Check for leaks.
 * Print the frame header of any currently allocated frame, assuming there
 * should be none at this point.
 */
void fc_frame_leak_check(void);

#endif /* _FC_FRAME_H_ */
Commit	Line	Data
42e9a92f RL	1	/*
	2	* Copyright(c) 2007 Intel Corporation. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or modify it
	5	* under the terms and conditions of the GNU General Public License,
	6	* version 2, as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope it will be useful, but WITHOUT
	9	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	10	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	11	* more details.
	12	*
	13	* You should have received a copy of the GNU General Public License along with
	14	* this program; if not, write to the Free Software Foundation, Inc.,
	15	* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
	16	*
	17	* Maintained at www.Open-FCoE.org
	18	*/
	19
	20	#ifndef _FC_FRAME_H_
	21	#define _FC_FRAME_H_
	22
	23	#include <linux/scatterlist.h>
	24	#include <linux/skbuff.h>
	25	#include <scsi/scsi_cmnd.h>
	26
	27	#include <scsi/fc/fc_fs.h>
	28	#include <scsi/fc/fc_fcp.h>
	29	#include <scsi/fc/fc_encaps.h>
	30
11b56188 CL	31	#include <linux/if_ether.h>
11b56188 CL	32
42e9a92f RL	33	/*
	34	* The fc_frame interface is used to pass frame data between functions.
	35	* The frame includes the data buffer, length, and SOF / EOF delimiter types.
	36	* A pointer to the port structure of the receiving port is also includeded.
	37	*/
	38
	39	#define FC_FRAME_HEADROOM 32 /* headroom for VLAN + FCoE headers */
	40	#define FC_FRAME_TAILROOM 8 /* trailer space for FCoE */
	41
d37322a4 YZ	42	/* Max number of skb frags allowed, reserving one for fcoe_crc_eof page */
	43	#define FC_FRAME_SG_LEN (MAX_SKB_FRAGS - 1)
	44
42e9a92f RL	45	#define fp_skb(fp) (&((fp)->skb))
	46	#define fr_hdr(fp) ((fp)->skb.data)
	47	#define fr_len(fp) ((fp)->skb.len)
	48	#define fr_cb(fp) ((struct fcoe_rcv_info *)&((fp)->skb.cb[0]))
	49	#define fr_dev(fp) (fr_cb(fp)->fr_dev)
	50	#define fr_seq(fp) (fr_cb(fp)->fr_seq)
	51	#define fr_sof(fp) (fr_cb(fp)->fr_sof)
	52	#define fr_eof(fp) (fr_cb(fp)->fr_eof)
	53	#define fr_flags(fp) (fr_cb(fp)->fr_flags)
	54	#define fr_max_payload(fp) (fr_cb(fp)->fr_max_payload)
b277d2aa	55	#define fr_fsp(fp) (fr_cb(fp)->fr_fsp)
42e9a92f RL	56	#define fr_crc(fp) (fr_cb(fp)->fr_crc)
	57
	58	struct fc_frame {
	59	struct sk_buff skb;
	60	};
	61
	62	struct fcoe_rcv_info {
	63	struct packet_type *ptype;
	64	struct fc_lport fr_dev; / transport layer private pointer */
	65	struct fc_seq fr_seq; / for use with exchange manager */
b277d2aa	66	struct fc_fcp_pkt fr_fsp; / for the corresponding fcp I/O */
42e9a92f RL	67	u32 fr_crc;
	68	u16 fr_max_payload; /* max FC payload */
	69	enum fc_sof fr_sof; /* start of frame delimiter */
	70	enum fc_eof fr_eof; /* end of frame delimiter */
	71	u8 fr_flags; /* flags - see below */
11b56188	72	u8 granted_mac[ETH_ALEN]; /* FCoE MAC address */
42e9a92f RL	73	};
	74
	75
	76	/*
	77	* Get fc_frame pointer for an skb that's already been imported.
	78	*/
	79	static inline struct fcoe_rcv_info fcoe_dev_from_skb(const struct sk_buff skb)
	80	{
	81	BUILD_BUG_ON(sizeof(struct fcoe_rcv_info) > sizeof(skb->cb));
	82	return (struct fcoe_rcv_info *) skb->cb;
	83	}
	84
	85	/*
	86	* fr_flags.
	87	*/
	88	#define FCPHF_CRC_UNCHECKED 0x01 /* CRC not computed, still appended */
	89
	90	/*
	91	* Initialize a frame.
	92	* We don't do a complete memset here for performance reasons.
	93	* The caller must set fr_free, fr_hdr, fr_len, fr_sof, and fr_eof eventually.
	94	*/
	95	static inline void fc_frame_init(struct fc_frame *fp)
	96	{
	97	fr_dev(fp) = NULL;
	98	fr_seq(fp) = NULL;
	99	fr_flags(fp) = 0;
	100	}
	101
	102	struct fc_frame fc_frame_alloc_fill(struct fc_lport , size_t payload_len);
a7bbc7f4	103	struct fc_frame *_fc_frame_alloc(size_t payload_len);
42e9a92f RL	104
	105	/*
	106	* Allocate fc_frame structure and buffer. Set the initial length to
	107	* payload_size + sizeof (struct fc_frame_header).
	108	*/
	109	static inline struct fc_frame fc_frame_alloc(struct fc_lport dev, size_t len)
	110	{
	111	struct fc_frame *fp;
	112
	113	/*
	114	* Note: Since len will often be a constant multiple of 4,
	115	* this check will usually be evaluated and eliminated at compile time.
	116	*/
a7bbc7f4	117	if (len && len % 4)
42e9a92f RL	118	fp = fc_frame_alloc_fill(dev, len);
42e9a92f RL	119	else
a7bbc7f4	120	fp = _fc_frame_alloc(len);
42e9a92f RL	121	return fp;
	122	}
	123
	124	/*
	125	* Free the fc_frame structure and buffer.
	126	*/
	127	static inline void fc_frame_free(struct fc_frame *fp)
	128	{
	129	kfree_skb(fp_skb(fp));
	130	}
	131
	132	static inline int fc_frame_is_linear(struct fc_frame *fp)
	133	{
	134	return !skb_is_nonlinear(fp_skb(fp));
	135	}
	136
	137	/*
	138	* Get frame header from message in fc_frame structure.
	139	* This hides a cast and provides a place to add some checking.
	140	*/
	141	static inline
	142	struct fc_frame_header fc_frame_header_get(const struct fc_frame fp)
	143	{
	144	WARN_ON(fr_len(fp) < sizeof(struct fc_frame_header));
	145	return (struct fc_frame_header *) fr_hdr(fp);
	146	}
	147
	148	/*
	149	* Get frame payload from message in fc_frame structure.
	150	* This hides a cast and provides a place to add some checking.
	151	* The len parameter is the minimum length for the payload portion.
	152	* Returns NULL if the frame is too short.
	153	*
	154	* This assumes the interesting part of the payload is in the first part
	155	* of the buffer for received data. This may not be appropriate to use for
	156	* buffers being transmitted.
	157	*/
	158	static inline void fc_frame_payload_get(const struct fc_frame fp,
	159	size_t len)
	160	{
	161	void *pp = NULL;
	162
	163	if (fr_len(fp) >= sizeof(struct fc_frame_header) + len)
	164	pp = fc_frame_header_get(fp) + 1;
	165	return pp;
	166	}
	167
	168	/*
	169	* Get frame payload opcode (first byte) from message in fc_frame structure.
	170	* This hides a cast and provides a place to add some checking. Return 0
	171	* if the frame has no payload.
	172	*/
	173	static inline u8 fc_frame_payload_op(const struct fc_frame *fp)
	174	{
	175	u8 *cp;
	176
	177	cp = fc_frame_payload_get(fp, sizeof(u8));
	178	if (!cp)
	179	return 0;
	180	return *cp;
	181
	182	}
	183
	184	/*
185	* Get FC class from frame.
186	*/
187	static inline enum fc_class fc_frame_class(const struct fc_frame *fp)
188	{
189	return fc_sof_class(fr_sof(fp));
190	}
191
192	/*
193	* Check the CRC in a frame.
194	* The CRC immediately follows the last data item AFTER the length.
195	* The return value is zero if the CRC matches.
196	*/
197	u32 fc_frame_crc_check(struct fc_frame *);
198
199	static inline u8 fc_frame_rctl(const struct fc_frame *fp)
200	{
201	return fc_frame_header_get(fp)->fh_r_ctl;
202	}
203
204	static inline bool fc_frame_is_cmd(const struct fc_frame *fp)
205	{
206	return fc_frame_rctl(fp) == FC_RCTL_DD_UNSOL_CMD;
207	}
208
42e9a92f RL	209	/*
	210	* Check for leaks.
	211	* Print the frame header of any currently allocated frame, assuming there
	212	* should be none at this point.
	213	*/
	214	void fc_frame_leak_check(void);
	215
	216	#endif /* _FC_FRAME_H_ */