1 /****************************************************************************** 2 * evtchn.h 3 * 4 * Data structures and definitions private to the FreeBSD implementation 5 * of the Xen event channel API. 6 * 7 * Copyright (c) 2004, K A Fraser 8 * Copyright (c) 2012, Spectra Logic Corporation 9 * Copyright © 2022, Elliott Mitchell 10 * 11 * This file may be distributed separately from the Linux kernel, or 12 * incorporated into other software packages, subject to the following license: 13 * 14 * Permission is hereby granted, free of charge, to any person obtaining a copy 15 * of this source file (the "Software"), to deal in the Software without 16 * restriction, including without limitation the rights to use, copy, modify, 17 * merge, publish, distribute, sublicense, and/or sell copies of the Software, 18 * and to permit persons to whom the Software is furnished to do so, subject to 19 * the following conditions: 20 * 21 * The above copyright notice and this permission notice shall be included in 22 * all copies or substantial portions of the Software. 23 * 24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 25 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 26 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 27 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 28 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 29 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 30 * IN THE SOFTWARE. 31 */ 32 33 #ifndef __XEN_EVTCHN_EVTCHNVAR_H__ 34 #define __XEN_EVTCHN_EVTCHNVAR_H__ 35 36 #include <xen/hypervisor.h> 37 #include <contrib/xen/event_channel.h> 38 39 /* Macros for accessing event channel values */ 40 #define EVTCHN_PTR(type, port) ({ \ 41 KASSERT(port < nitems(HYPERVISOR_shared_info->evtchn_##type) * \ 42 sizeof(xen_ulong_t) * 8, ("Invalid event channel port")); \ 43 (HYPERVISOR_shared_info->evtchn_##type + ((port) / __LONG_BIT));\ 44 }) 45 #define EVTCHN_BIT(port) ((port) & (__LONG_BIT - 1)) 46 #define EVTCHN_MASK(port) (1UL << EVTCHN_BIT(port)) 47 48 /** 49 * Disable signal delivery for an event channel port, returning its 50 * previous mask state. 51 * 52 * \param port The event channel port to query and mask. 53 * 54 * \returns 1 if event delivery was previously disabled. Otherwise 0. 55 */ 56 static inline int 57 evtchn_test_and_set_mask(evtchn_port_t port) 58 { 59 60 return (atomic_testandset_xen_ulong(EVTCHN_PTR(mask, port), 61 EVTCHN_BIT(port))); 62 } 63 64 /** 65 * Clear any pending event for the given event channel port. 66 * 67 * \param port The event channel port to clear. 68 */ 69 static inline void 70 evtchn_clear_port(evtchn_port_t port) 71 { 72 73 atomic_clear_xen_ulong(EVTCHN_PTR(pending, port), EVTCHN_MASK(port)); 74 } 75 76 /** 77 * Disable signal delivery for an event channel port. 78 * 79 * \param port The event channel port to mask. 80 */ 81 static inline void 82 evtchn_mask_port(evtchn_port_t port) 83 { 84 85 atomic_set_xen_ulong(EVTCHN_PTR(mask, port), EVTCHN_MASK(port)); 86 } 87 88 /** 89 * Enable signal delivery for an event channel port. 90 * 91 * \param port The event channel port to enable. 92 */ 93 static inline void 94 evtchn_unmask_port(evtchn_port_t port) 95 { 96 evtchn_unmask_t op = { .port = port }; 97 98 HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &op); 99 } 100 101 #endif /* __XEN_EVTCHN_EVTCHNVAR_H__ */ 102