1 /* SPDX-License-Identifier: Apache-2.0 */ 2 3 #ifndef _LIBMCTP_H 4 #define _LIBMCTP_H 5 6 #include <stdbool.h> 7 #include <stdint.h> 8 #include <stddef.h> 9 10 typedef uint8_t mctp_eid_t; 11 12 /* MCTP packet definitions */ 13 struct mctp_hdr { 14 uint8_t ver; 15 uint8_t dest; 16 uint8_t src; 17 uint8_t flags_seq_tag; 18 }; 19 20 /* Definitions for flags_seq_tag field */ 21 #define MCTP_HDR_FLAG_SOM (1<<7) 22 #define MCTP_HDR_FLAG_EOM (1<<6) 23 #define MCTP_HDR_FLAG_TO (1<<3) 24 #define MCTP_HDR_SEQ_SHIFT (5) 25 #define MCTP_HDR_SEQ_MASK (0x3) 26 #define MCTP_HDR_TAG_SHIFT (0) 27 #define MCTP_HDR_TAG_MASK (0x7) 28 29 /* Maximum size of *payload* data in a MCTP packet 30 * @todo: dynamic sixing based on channel implementation. 31 */ 32 #define MCTP_MTU 64 33 34 /* packet buffers */ 35 36 /* Allow a little space before the MCTP header in the packet, for bindings that 37 * may add their own header 38 */ 39 #define MCTP_PKTBUF_BINDING_PAD 2 40 41 #define MCTP_PKTBUF_SIZE (MCTP_PKTBUF_BINDING_PAD + \ 42 (sizeof(struct mctp_hdr) + MCTP_MTU)) 43 44 struct mctp_pktbuf { 45 unsigned char data[MCTP_PKTBUF_SIZE]; 46 uint8_t start, end; 47 uint8_t mctp_hdr_off; 48 struct mctp_pktbuf *next; 49 }; 50 51 struct mctp_pktbuf *mctp_pktbuf_alloc(uint8_t len); 52 void mctp_pktbuf_free(struct mctp_pktbuf *pkt); 53 struct mctp_hdr *mctp_pktbuf_hdr(struct mctp_pktbuf *pkt); 54 void *mctp_pktbuf_data(struct mctp_pktbuf *pkt); 55 uint8_t mctp_pktbuf_size(struct mctp_pktbuf *pkt); 56 void *mctp_pktbuf_alloc_start(struct mctp_pktbuf *pkt, uint8_t size); 57 void *mctp_pktbuf_alloc_end(struct mctp_pktbuf *pkt, uint8_t size); 58 int mctp_pktbuf_push(struct mctp_pktbuf *pkt, void *data, uint8_t len); 59 60 /* MCTP core */ 61 struct mctp; 62 struct mctp_bus; 63 struct mctp_binding; 64 65 struct mctp *mctp_init(void); 66 67 /* Register a binding to the MCTP core, and creates a bus (populating 68 * binding->bus). 69 */ 70 int mctp_register_bus(struct mctp *mctp, 71 struct mctp_binding *binding, 72 mctp_eid_t eid); 73 74 typedef void (*mctp_rx_fn)(uint8_t src_eid, void *data, 75 void *msg, size_t len); 76 77 int mctp_set_rx_all(struct mctp *mctp, mctp_rx_fn fn, void *data); 78 79 int mctp_message_tx(struct mctp *mctp, mctp_eid_t eid, 80 void *msg, size_t msg_len); 81 82 /* hardware bindings */ 83 struct mctp_binding { 84 const char *name; 85 uint8_t version; 86 struct mctp_bus *bus; 87 struct mctp *mctp; 88 int (*tx)(struct mctp_binding *binding, 89 struct mctp_pktbuf *pkt); 90 }; 91 92 void mctp_binding_set_tx_enabled(struct mctp_binding *binding, bool enable); 93 94 void mctp_bus_rx(struct mctp_binding *binding, struct mctp_pktbuf *pkt); 95 96 /* environment-specific allocation */ 97 void mctp_set_alloc_ops(void *(*alloc)(size_t), 98 void (*free)(void *), 99 void *(realloc)(void *, size_t)); 100 101 102 #endif /* _LIBMCTP_H */ 103