1 /* 2 * Copyright (c) 2015 Carlos Pizano-Uribe cpu@chromium.org 3 * 4 * Use of this source code is governed by a MIT-style 5 * license that can be found in the LICENSE file or at 6 * https://opensource.org/licenses/MIT 7 */ 8 #pragma once 9 10 #include <lk/compiler.h> 11 #include <sys/types.h> 12 13 __BEGIN_CDECLS 14 15 /* Ports are named, opaque objects and come in three flavors, the 16 * write-side, the read-side and a port group which is a collection 17 * of read-side ports. 18 */ 19 20 #define PORT_NAME_LEN 12 21 22 typedef void *port_t; 23 24 /* A Port packet is wide enough to carry two full words of data */ 25 #define PORT_PACKET_LEN (sizeof(void *) * 2) 26 typedef struct { 27 char value[PORT_PACKET_LEN]; 28 } port_packet_t; 29 30 typedef struct { 31 void *ctx; 32 port_packet_t packet; 33 } port_result_t; 34 35 typedef enum { 36 PORT_MODE_BROADCAST = 0, 37 PORT_MODE_UNICAST = 1, 38 PORT_MODE_BIG_BUFFER = 2, 39 } port_mode_t; 40 41 /* Inits the port subsystem 42 */ 43 void port_init(void); 44 45 /* Make a named write-side port. broadcast ports can be opened by any 46 * number of read-clients. |name| can be up to PORT_NAME_LEN chars. If 47 * the write port exists it is returned even if the |mode| does not match. 48 */ 49 status_t port_create(const char *name, port_mode_t mode, port_t *port); 50 51 /* Make a read-side port. Only non-destroyed existing write ports can 52 * be opened with this api. Unicast ports can only be opened once. For 53 * broadcast ports, each call if successful returns a new port. 54 */ 55 status_t port_open(const char *name, void *ctx, port_t *port); 56 57 /* Creates a read-side port group which behaves just like a regular 58 * read-side port. A given port can only be assoicated with one port group. 59 */ 60 status_t port_group(port_t *ports, size_t count, port_t *group); 61 62 /* Adds a read-side port to an existing port group. 63 */ 64 status_t port_group_add(port_t group, port_t port); 65 66 /* Removes a read-side port to an existing port group. 67 */ 68 status_t port_group_remove(port_t group, port_t port); 69 70 /* Write to a port |count| packets, non-blocking, all or none atomic success. 71 */ 72 status_t port_write(port_t port, const port_packet_t *pk, size_t count); 73 74 /* Read one packet from the port or port group, blocking. The |result| contains 75 * the port that the message was read from. If |timeout| is zero the call 76 * does not block. 77 */ 78 status_t port_read(port_t port, lk_time_t timeout, port_result_t *result); 79 80 /* Destroy the write-side port, flush queued packets and release all resources, 81 * all calls will now fail on that port. Only a closed port can be destroyed. 82 */ 83 status_t port_destroy(port_t port); 84 85 /* Close the read-side port or the write side port. A closed write side port 86 * can be opened and the pending packets read. closing a port group does not 87 * close the included ports. 88 */ 89 status_t port_close(port_t port); 90 91 __END_CDECLS 92