Oleksandr Andrushchenko | 673fd82 | 2020-08-06 12:42:49 +0300 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * (C) 2003 - Rolf Neugebauer - Intel Research Cambridge |
| 4 | * (C) 2005 - Grzegorz Milos - Intel Research Cambridge |
| 5 | * (C) 2020 - EPAM Systems Inc. |
| 6 | * |
| 7 | * File: events.c [1] |
| 8 | * Author: Rolf Neugebauer (neugebar@dcs.gla.ac.uk) |
| 9 | * Changes: Grzegorz Milos (gm281@cam.ac.uk) |
| 10 | * |
| 11 | * Date: Jul 2003, changes Jun 2005 |
| 12 | * |
| 13 | * Description: Deals with events received on event channels |
| 14 | * |
| 15 | * [1] - http://xenbits.xen.org/gitweb/?p=mini-os.git;a=summary |
| 16 | */ |
| 17 | #include <common.h> |
| 18 | #include <log.h> |
| 19 | |
| 20 | #include <asm/io.h> |
| 21 | #include <asm/xen/system.h> |
| 22 | |
| 23 | #include <xen/events.h> |
| 24 | #include <xen/hvm.h> |
| 25 | |
Peng Fan | 384d5cf | 2020-08-06 12:42:50 +0300 | [diff] [blame^] | 26 | extern u32 console_evtchn; |
| 27 | |
Oleksandr Andrushchenko | 673fd82 | 2020-08-06 12:42:49 +0300 | [diff] [blame] | 28 | #define NR_EVS 1024 |
| 29 | |
| 30 | /** |
| 31 | * struct _ev_action - represents a event handler. |
| 32 | * |
| 33 | * Chaining or sharing is not allowed |
| 34 | */ |
| 35 | struct _ev_action { |
| 36 | void (*handler)(evtchn_port_t port, struct pt_regs *regs, void *data); |
| 37 | void *data; |
| 38 | u32 count; |
| 39 | }; |
| 40 | |
| 41 | static struct _ev_action ev_actions[NR_EVS]; |
| 42 | void default_handler(evtchn_port_t port, struct pt_regs *regs, void *data); |
| 43 | |
| 44 | static unsigned long bound_ports[NR_EVS / (8 * sizeof(unsigned long))]; |
| 45 | |
| 46 | void unbind_all_ports(void) |
| 47 | { |
| 48 | int i; |
| 49 | int cpu = 0; |
| 50 | struct shared_info *s = HYPERVISOR_shared_info; |
| 51 | struct vcpu_info *vcpu_info = &s->vcpu_info[cpu]; |
| 52 | |
| 53 | for (i = 0; i < NR_EVS; i++) { |
Peng Fan | 384d5cf | 2020-08-06 12:42:50 +0300 | [diff] [blame^] | 54 | if (i == console_evtchn) |
| 55 | continue; |
Oleksandr Andrushchenko | 673fd82 | 2020-08-06 12:42:49 +0300 | [diff] [blame] | 56 | if (test_and_clear_bit(i, bound_ports)) { |
| 57 | printf("port %d still bound!\n", i); |
| 58 | unbind_evtchn(i); |
| 59 | } |
| 60 | } |
| 61 | vcpu_info->evtchn_upcall_pending = 0; |
| 62 | vcpu_info->evtchn_pending_sel = 0; |
| 63 | } |
| 64 | |
| 65 | int do_event(evtchn_port_t port, struct pt_regs *regs) |
| 66 | { |
| 67 | struct _ev_action *action; |
| 68 | |
| 69 | clear_evtchn(port); |
| 70 | |
| 71 | if (port >= NR_EVS) { |
| 72 | printk("WARN: do_event(): Port number too large: %d\n", port); |
| 73 | return 1; |
| 74 | } |
| 75 | |
| 76 | action = &ev_actions[port]; |
| 77 | action->count++; |
| 78 | |
| 79 | /* call the handler */ |
| 80 | action->handler(port, regs, action->data); |
| 81 | |
| 82 | return 1; |
| 83 | } |
| 84 | |
| 85 | evtchn_port_t bind_evtchn(evtchn_port_t port, |
| 86 | void (*handler)(evtchn_port_t, struct pt_regs *, void *), |
| 87 | void *data) |
| 88 | { |
| 89 | if (ev_actions[port].handler != default_handler) |
| 90 | printf("WARN: Handler for port %d already registered, replacing\n", |
| 91 | port); |
| 92 | |
| 93 | ev_actions[port].data = data; |
| 94 | wmb(); |
| 95 | ev_actions[port].handler = handler; |
| 96 | synch_set_bit(port, bound_ports); |
| 97 | |
| 98 | return port; |
| 99 | } |
| 100 | |
| 101 | /** |
| 102 | * unbind_evtchn() - Unbind event channel for selected port |
| 103 | */ |
| 104 | void unbind_evtchn(evtchn_port_t port) |
| 105 | { |
| 106 | struct evtchn_close close; |
| 107 | int rc; |
| 108 | |
| 109 | if (ev_actions[port].handler == default_handler) |
| 110 | printf("WARN: No handler for port %d when unbinding\n", port); |
| 111 | mask_evtchn(port); |
| 112 | clear_evtchn(port); |
| 113 | |
| 114 | ev_actions[port].handler = default_handler; |
| 115 | wmb(); |
| 116 | ev_actions[port].data = NULL; |
| 117 | synch_clear_bit(port, bound_ports); |
| 118 | |
| 119 | close.port = port; |
| 120 | rc = HYPERVISOR_event_channel_op(EVTCHNOP_close, &close); |
| 121 | if (rc) |
| 122 | printf("WARN: close_port %d failed rc=%d. ignored\n", port, rc); |
| 123 | } |
| 124 | |
| 125 | void default_handler(evtchn_port_t port, struct pt_regs *regs, void *ignore) |
| 126 | { |
| 127 | debug("[Port %d] - event received\n", port); |
| 128 | } |
| 129 | |
| 130 | /** |
| 131 | * evtchn_alloc_unbound() - Create a port available to the pal for |
| 132 | * exchanging notifications. |
| 133 | * |
| 134 | * Unfortunate confusion of terminology: the port is unbound as far |
| 135 | * as Xen is concerned, but we automatically bind a handler to it. |
| 136 | * |
| 137 | * Return: The result of the hypervisor call. |
| 138 | */ |
| 139 | int evtchn_alloc_unbound(domid_t pal, |
| 140 | void (*handler)(evtchn_port_t, struct pt_regs *, void *), |
| 141 | void *data, evtchn_port_t *port) |
| 142 | { |
| 143 | int rc; |
| 144 | |
| 145 | struct evtchn_alloc_unbound op; |
| 146 | |
| 147 | op.dom = DOMID_SELF; |
| 148 | op.remote_dom = pal; |
| 149 | rc = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound, &op); |
| 150 | if (rc) { |
| 151 | printf("ERROR: alloc_unbound failed with rc=%d", rc); |
| 152 | return rc; |
| 153 | } |
| 154 | if (!handler) |
| 155 | handler = default_handler; |
| 156 | *port = bind_evtchn(op.port, handler, data); |
| 157 | return rc; |
| 158 | } |
| 159 | |
| 160 | /** |
| 161 | * eventchn_poll() - Event channel polling function |
| 162 | * |
| 163 | * Check and process any pending events |
| 164 | */ |
| 165 | void eventchn_poll(void) |
| 166 | { |
| 167 | do_hypervisor_callback(NULL); |
| 168 | } |
| 169 | |
| 170 | /** |
| 171 | * init_events() - Initialize event handler |
| 172 | * |
| 173 | * Initially all events are without a handler and disabled. |
| 174 | */ |
| 175 | void init_events(void) |
| 176 | { |
| 177 | int i; |
| 178 | |
| 179 | debug("%s\n", __func__); |
| 180 | |
| 181 | for (i = 0; i < NR_EVS; i++) { |
| 182 | ev_actions[i].handler = default_handler; |
| 183 | mask_evtchn(i); |
| 184 | } |
| 185 | } |
| 186 | |
| 187 | /** |
| 188 | * fini_events() - Close all ports |
| 189 | * |
| 190 | * Mask and clear event channels. Close port using EVTCHNOP_close |
| 191 | * hypercall. |
| 192 | */ |
| 193 | void fini_events(void) |
| 194 | { |
| 195 | debug("%s\n", __func__); |
| 196 | /* Dealloc all events */ |
| 197 | unbind_all_ports(); |
| 198 | } |
| 199 | |