1 /* SPDX-License-Identifier: Apache-2.0 */ 2 3 #ifndef _LIBMCTP_H 4 #define _LIBMCTP_H 5 6 #ifdef __cplusplus 7 extern "C" { 8 #endif 9 10 #include <stdbool.h> 11 #include <stdint.h> 12 #include <stddef.h> 13 14 typedef uint8_t mctp_eid_t; 15 16 /* MCTP packet definitions */ 17 struct mctp_hdr { 18 uint8_t ver; 19 uint8_t dest; 20 uint8_t src; 21 uint8_t flags_seq_tag; 22 }; 23 24 /* Definitions for flags_seq_tag field */ 25 #define MCTP_HDR_FLAG_SOM (1<<7) 26 #define MCTP_HDR_FLAG_EOM (1<<6) 27 #define MCTP_HDR_FLAG_TO (1<<3) 28 #define MCTP_HDR_SEQ_SHIFT (4) 29 #define MCTP_HDR_SEQ_MASK (0x3) 30 #define MCTP_HDR_TAG_SHIFT (0) 31 #define MCTP_HDR_TAG_MASK (0x7) 32 33 /* Maximum size of *payload* data in a MCTP packet 34 * @todo: dynamic sixing based on channel implementation. 35 */ 36 #define MCTP_MTU 64 37 38 /* packet buffers */ 39 40 /* Allow a little space before the MCTP header in the packet, for bindings that 41 * may add their own header 42 */ 43 #define MCTP_PKTBUF_BINDING_PAD 2 44 45 #define MCTP_PKTBUF_SIZE (MCTP_PKTBUF_BINDING_PAD + \ 46 (sizeof(struct mctp_hdr) + MCTP_MTU)) 47 48 struct mctp_pktbuf { 49 unsigned char data[MCTP_PKTBUF_SIZE]; 50 uint8_t start, end; 51 uint8_t mctp_hdr_off; 52 struct mctp_pktbuf *next; 53 }; 54 55 struct mctp_pktbuf *mctp_pktbuf_alloc(uint8_t len); 56 void mctp_pktbuf_free(struct mctp_pktbuf *pkt); 57 struct mctp_hdr *mctp_pktbuf_hdr(struct mctp_pktbuf *pkt); 58 void *mctp_pktbuf_data(struct mctp_pktbuf *pkt); 59 uint8_t mctp_pktbuf_size(struct mctp_pktbuf *pkt); 60 void *mctp_pktbuf_alloc_start(struct mctp_pktbuf *pkt, uint8_t size); 61 void *mctp_pktbuf_alloc_end(struct mctp_pktbuf *pkt, uint8_t size); 62 int mctp_pktbuf_push(struct mctp_pktbuf *pkt, void *data, uint8_t len); 63 64 /* MCTP core */ 65 struct mctp; 66 struct mctp_bus; 67 struct mctp_binding; 68 69 struct mctp *mctp_init(void); 70 71 /* Register a binding to the MCTP core, and creates a bus (populating 72 * binding->bus). 73 */ 74 int mctp_register_bus(struct mctp *mctp, 75 struct mctp_binding *binding, 76 mctp_eid_t eid); 77 78 typedef void (*mctp_rx_fn)(uint8_t src_eid, void *data, 79 void *msg, size_t len); 80 81 int mctp_set_rx_all(struct mctp *mctp, mctp_rx_fn fn, void *data); 82 83 int mctp_message_tx(struct mctp *mctp, mctp_eid_t eid, 84 void *msg, size_t msg_len); 85 86 /* hardware bindings */ 87 struct mctp_binding { 88 const char *name; 89 uint8_t version; 90 struct mctp_bus *bus; 91 struct mctp *mctp; 92 int (*tx)(struct mctp_binding *binding, 93 struct mctp_pktbuf *pkt); 94 }; 95 96 void mctp_binding_set_tx_enabled(struct mctp_binding *binding, bool enable); 97 98 void mctp_bus_rx(struct mctp_binding *binding, struct mctp_pktbuf *pkt); 99 100 /* environment-specific allocation */ 101 void mctp_set_alloc_ops(void *(*alloc)(size_t), 102 void (*free)(void *), 103 void *(realloc)(void *, size_t)); 104 105 106 #ifdef __cplusplus 107 } 108 #endif 109 110 #endif /* _LIBMCTP_H */ 111