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Diffstat (limited to 'include/scsi/fc_frame.h')
| -rw-r--r-- | include/scsi/fc_frame.h | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/include/scsi/fc_frame.h b/include/scsi/fc_frame.h new file mode 100644 index 00000000000..04d34a71355 --- /dev/null +++ b/include/scsi/fc_frame.h @@ -0,0 +1,242 @@ +/* + * 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> + +/* + * 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 */ + +/* + * Information about an individual fibre channel frame received or to be sent. + * The buffer may be in up to 4 additional non-contiguous sections, + * but the linear section must hold the frame header. + */ +#define FC_FRAME_SG_LEN 4 /* scatter/gather list maximum length */ + +#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_cmd(fp) (fr_cb(fp)->fr_cmd) +#define fr_dir(fp) (fr_cmd(fp)->sc_data_direction) +#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 scsi_cmnd *fr_cmd; /* for use of scsi command */ + 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 */ +}; + + +/* + * 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); + +/* + * Get frame for sending via port. + */ +static inline struct fc_frame *_fc_frame_alloc(struct fc_lport *dev, + size_t payload_len) +{ + return __fc_frame_alloc(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 % 4) != 0) + fp = fc_frame_alloc_fill(dev, len); + else + fp = _fc_frame_alloc(dev, 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; +} + +static inline bool fc_frame_is_read(const struct fc_frame *fp) +{ + if (fc_frame_is_cmd(fp) && fr_cmd(fp)) + return fr_dir(fp) == DMA_FROM_DEVICE; + return false; +} + +static inline bool fc_frame_is_write(const struct fc_frame *fp) +{ + if (fc_frame_is_cmd(fp) && fr_cmd(fp)) + return fr_dir(fp) == DMA_TO_DEVICE; + return false; +} + +/* + * 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_ */ |