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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206/* SPDX-License-Identifier: GPL-2.0+ *//* * SSH message builder functions. * * Copyright (C) 2019-2022 Maximilian Luz <luzmaximilian@gmail.com> */
#ifndef _SURFACE_AGGREGATOR_SSH_MSGB_H#define _SURFACE_AGGREGATOR_SSH_MSGB_H
#include <linux/unaligned.h>#include <linux/types.h>
#include <linux/surface_aggregator/controller.h>#include <linux/surface_aggregator/serial_hub.h>
/** * struct msgbuf - Buffer struct to construct SSH messages. * @begin: Pointer to the beginning of the allocated buffer space. * @end: Pointer to the end (one past last element) of the allocated buffer * space. * @ptr: Pointer to the first free element in the buffer. */struct msgbuf { u8 *begin; u8 *end; u8 *ptr;};
/** * msgb_init() - Initialize the given message buffer struct. * @msgb: The buffer struct to initialize * @ptr: Pointer to the underlying memory by which the buffer will be backed. * @cap: Size of the underlying memory. * * Initialize the given message buffer struct using the provided memory as * backing. */static inline void msgb_init(struct msgbuf *msgb, u8 *ptr, size_t cap){ msgb->begin = ptr; msgb->end = ptr + cap; msgb->ptr = ptr;}
/** * msgb_bytes_used() - Return the current number of bytes used in the buffer. * @msgb: The message buffer. */static inline size_t msgb_bytes_used(const struct msgbuf *msgb){ return msgb->ptr - msgb->begin;}
static inline void __msgb_push_u8(struct msgbuf *msgb, u8 value){ *msgb->ptr = value; msgb->ptr += sizeof(u8);}
static inline void __msgb_push_u16(struct msgbuf *msgb, u16 value){ put_unaligned_le16(value, msgb->ptr); msgb->ptr += sizeof(u16);}
/** * msgb_push_u16() - Push a u16 value to the buffer. * @msgb: The message buffer. * @value: The value to push to the buffer. */static inline void msgb_push_u16(struct msgbuf *msgb, u16 value){ if (WARN_ON(msgb->ptr + sizeof(u16) > msgb->end)) return;
__msgb_push_u16(msgb, value);}
/** * msgb_push_syn() - Push SSH SYN bytes to the buffer. * @msgb: The message buffer. */static inline void msgb_push_syn(struct msgbuf *msgb){ msgb_push_u16(msgb, SSH_MSG_SYN);}
/** * msgb_push_buf() - Push raw data to the buffer. * @msgb: The message buffer. * @buf: The data to push to the buffer. * @len: The length of the data to push to the buffer. */static inline void msgb_push_buf(struct msgbuf *msgb, const u8 *buf, size_t len){ msgb->ptr = memcpy(msgb->ptr, buf, len) + len;}
/** * msgb_push_crc() - Compute CRC and push it to the buffer. * @msgb: The message buffer. * @buf: The data for which the CRC should be computed. * @len: The length of the data for which the CRC should be computed. */static inline void msgb_push_crc(struct msgbuf *msgb, const u8 *buf, size_t len){ msgb_push_u16(msgb, ssh_crc(buf, len));}
/** * msgb_push_frame() - Push a SSH message frame header to the buffer. * @msgb: The message buffer * @ty: The type of the frame. * @len: The length of the payload of the frame. * @seq: The sequence ID of the frame/packet. */static inline void msgb_push_frame(struct msgbuf *msgb, u8 ty, u16 len, u8 seq){ u8 *const begin = msgb->ptr;
if (WARN_ON(msgb->ptr + sizeof(struct ssh_frame) > msgb->end)) return;
__msgb_push_u8(msgb, ty); /* Frame type. */ __msgb_push_u16(msgb, len); /* Frame payload length. */ __msgb_push_u8(msgb, seq); /* Frame sequence ID. */
msgb_push_crc(msgb, begin, msgb->ptr - begin);}
/** * msgb_push_ack() - Push a SSH ACK frame to the buffer. * @msgb: The message buffer * @seq: The sequence ID of the frame/packet to be ACKed. */static inline void msgb_push_ack(struct msgbuf *msgb, u8 seq){ /* SYN. */ msgb_push_syn(msgb);
/* ACK-type frame + CRC. */ msgb_push_frame(msgb, SSH_FRAME_TYPE_ACK, 0x00, seq);
/* Payload CRC (ACK-type frames do not have a payload). */ msgb_push_crc(msgb, msgb->ptr, 0);}
/** * msgb_push_nak() - Push a SSH NAK frame to the buffer. * @msgb: The message buffer */static inline void msgb_push_nak(struct msgbuf *msgb){ /* SYN. */ msgb_push_syn(msgb);
/* NAK-type frame + CRC. */ msgb_push_frame(msgb, SSH_FRAME_TYPE_NAK, 0x00, 0x00);
/* Payload CRC (ACK-type frames do not have a payload). */ msgb_push_crc(msgb, msgb->ptr, 0);}
/** * msgb_push_cmd() - Push a SSH command frame with payload to the buffer. * @msgb: The message buffer. * @seq: The sequence ID (SEQ) of the frame/packet. * @rqid: The request ID (RQID) of the request contained in the frame. * @rqst: The request to wrap in the frame. */static inline void msgb_push_cmd(struct msgbuf *msgb, u8 seq, u16 rqid, const struct ssam_request *rqst){ const u8 type = SSH_FRAME_TYPE_DATA_SEQ; u8 *cmd;
/* SYN. */ msgb_push_syn(msgb);
/* Command frame + CRC. */ msgb_push_frame(msgb, type, sizeof(struct ssh_command) + rqst->length, seq);
/* Frame payload: Command struct + payload. */ if (WARN_ON(msgb->ptr + sizeof(struct ssh_command) > msgb->end)) return;
cmd = msgb->ptr;
__msgb_push_u8(msgb, SSH_PLD_TYPE_CMD); /* Payload type. */ __msgb_push_u8(msgb, rqst->target_category); /* Target category. */ __msgb_push_u8(msgb, rqst->target_id); /* Target ID. */ __msgb_push_u8(msgb, SSAM_SSH_TID_HOST); /* Source ID. */ __msgb_push_u8(msgb, rqst->instance_id); /* Instance ID. */ __msgb_push_u16(msgb, rqid); /* Request ID. */ __msgb_push_u8(msgb, rqst->command_id); /* Command ID. */
/* Command payload. */ msgb_push_buf(msgb, rqst->payload, rqst->length);
/* CRC for command struct + payload. */ msgb_push_crc(msgb, cmd, msgb->ptr - cmd);}
#endif /* _SURFACE_AGGREGATOR_SSH_MSGB_H */