1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (C) 2017 - Cambridge Greys Ltd |
4 | * Copyright (C) 2011 - 2014 Cisco Systems Inc |
5 | * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
6 | */ |
7 | |
8 | #include <stdlib.h> |
9 | #include <errno.h> |
10 | #include <sys/epoll.h> |
11 | #include <signal.h> |
12 | #include <string.h> |
13 | #include <irq_user.h> |
14 | #include <os.h> |
15 | #include <um_malloc.h> |
16 | |
17 | /* Epoll support */ |
18 | |
19 | static int epollfd = -1; |
20 | |
21 | #define MAX_EPOLL_EVENTS 64 |
22 | |
23 | static struct epoll_event epoll_events[MAX_EPOLL_EVENTS]; |
24 | |
25 | /* Helper to return an Epoll data pointer from an epoll event structure. |
26 | * We need to keep this one on the userspace side to keep includes separate |
27 | */ |
28 | |
29 | void *os_epoll_get_data_pointer(int index) |
30 | { |
31 | return epoll_events[index].data.ptr; |
32 | } |
33 | |
34 | /* Helper to compare events versus the events in the epoll structure. |
35 | * Same as above - needs to be on the userspace side |
36 | */ |
37 | |
38 | |
39 | int os_epoll_triggered(int index, int events) |
40 | { |
41 | return epoll_events[index].events & events; |
42 | } |
43 | /* Helper to set the event mask. |
44 | * The event mask is opaque to the kernel side, because it does not have |
45 | * access to the right includes/defines for EPOLL constants. |
46 | */ |
47 | |
48 | int os_event_mask(enum um_irq_type irq_type) |
49 | { |
50 | if (irq_type == IRQ_READ) |
51 | return EPOLLIN | EPOLLPRI | EPOLLERR | EPOLLHUP | EPOLLRDHUP; |
52 | if (irq_type == IRQ_WRITE) |
53 | return EPOLLOUT; |
54 | return 0; |
55 | } |
56 | |
57 | /* |
58 | * Initial Epoll Setup |
59 | */ |
60 | int os_setup_epoll(void) |
61 | { |
62 | epollfd = epoll_create(MAX_EPOLL_EVENTS); |
63 | return epollfd; |
64 | } |
65 | |
66 | /* |
67 | * Helper to run the actual epoll_wait |
68 | */ |
69 | int os_waiting_for_events_epoll(void) |
70 | { |
71 | int n, err; |
72 | |
73 | n = epoll_wait(epollfd, |
74 | (struct epoll_event *) &epoll_events, MAX_EPOLL_EVENTS, 0); |
75 | if (n < 0) { |
76 | err = -errno; |
77 | if (errno != EINTR) |
78 | printk( |
79 | UM_KERN_ERR "os_waiting_for_events:" |
80 | " epoll returned %d, error = %s\n" , n, |
81 | strerror(errno) |
82 | ); |
83 | return err; |
84 | } |
85 | return n; |
86 | } |
87 | |
88 | |
89 | /* |
90 | * Helper to add a fd to epoll |
91 | */ |
92 | int os_add_epoll_fd(int events, int fd, void *data) |
93 | { |
94 | struct epoll_event event; |
95 | int result; |
96 | |
97 | event.data.ptr = data; |
98 | event.events = events | EPOLLET; |
99 | result = epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &event); |
100 | if ((result) && (errno == EEXIST)) |
101 | result = os_mod_epoll_fd(events, fd, data); |
102 | if (result) |
103 | printk("epollctl add err fd %d, %s\n" , fd, strerror(errno)); |
104 | return result; |
105 | } |
106 | |
107 | /* |
108 | * Helper to mod the fd event mask and/or data backreference |
109 | */ |
110 | int os_mod_epoll_fd(int events, int fd, void *data) |
111 | { |
112 | struct epoll_event event; |
113 | int result; |
114 | |
115 | event.data.ptr = data; |
116 | event.events = events; |
117 | result = epoll_ctl(epollfd, EPOLL_CTL_MOD, fd, &event); |
118 | if (result) |
119 | printk(UM_KERN_ERR |
120 | "epollctl mod err fd %d, %s\n" , fd, strerror(errno)); |
121 | return result; |
122 | } |
123 | |
124 | /* |
125 | * Helper to delete the epoll fd |
126 | */ |
127 | int os_del_epoll_fd(int fd) |
128 | { |
129 | struct epoll_event event; |
130 | /* This is quiet as we use this as IO ON/OFF - so it is often |
131 | * invoked on a non-existent fd |
132 | */ |
133 | return epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, &event); |
134 | } |
135 | |
136 | void os_set_ioignore(void) |
137 | { |
138 | signal(SIGIO, SIG_IGN); |
139 | } |
140 | |
141 | void os_close_epoll_fd(void) |
142 | { |
143 | /* Needed so we do not leak an fd when rebooting */ |
144 | os_close_file(epollfd); |
145 | } |
146 | |