1 /* 2 * This file and its contents are supplied under the terms of the 3 * Common Development and Distribution License ("CDDL"), version 1.0. 4 * You may only use this file in accordance with the terms of version 5 * 1.0 of the CDDL. 6 * 7 * A full copy of the text of the CDDL should have accompanied this 8 * source. A copy of the CDDL is also available via the Internet at 9 * http://www.illumos.org/license/CDDL. 10 */ 11 12 /* 13 * Copyright 2016 Joyent, Inc. 14 * Copyright 2025 Oxide Computer Company 15 */ 16 17 #ifndef _COMM_PAGE_H 18 #define _COMM_PAGE_H 19 20 #ifndef _ASM 21 #include <sys/types.h> 22 #include <sys/param.h> 23 #include <sys/time.h> 24 #include <sys/sysmacros.h> 25 #endif /* _ASM */ 26 27 #ifdef __cplusplus 28 extern "C" { 29 #endif 30 31 #ifndef _ASM 32 33 /* 34 * x86 comm page 35 * 36 * This struct defines the data format for the "comm page": kernel data made 37 * directly available to userspace for read-only operations. This enables 38 * facilities such as clock_gettime to operate entirely in userspace without 39 * the need for a trap or fasttrap. 40 * 41 * A note about 32-bit/64-bit compatibility: 42 * The current format of the comm page is designed to be consistent for both 43 * 32-bit and 64-bit programs running in a 64-bit kernel. On 32-bit kernels, 44 * the comm page is not exposed to userspace due to the difference in 45 * timespec_t sizing. 46 * 47 * This struct is instantiated "by hand" in assembly to preserve the global 48 * symbols it contains. That layout must be kept in sync with the structure 49 * defined here. 50 * See: "uts/i86pc/ml/comm_page.S" 51 */ 52 typedef struct comm_page_s { 53 hrtime_t cp_tsc_last; 54 hrtime_t cp_tsc_hrtime_base; 55 hrtime_t cp_tsc_resume_cap; 56 uint32_t cp_tsc_type; 57 uint32_t cp_tsc_max_delta; 58 59 volatile uint32_t cp_hres_lock; /* must be 8-byte aligned */ 60 uint32_t cp_nsec_scale; 61 int64_t cp_hrestime_adj; 62 hrtime_t cp_hres_last_tick; 63 uint32_t cp_tsc_ncpu; 64 uint32_t _cp_pad0; 65 volatile int64_t cp_hrestime[2]; 66 uint64_t _cp_pad1[502]; /* pad to page boundary */ 67 #if defined(_MACHDEP) 68 hrtime_t cp_tsc_sync_tick_delta[NCPU]; 69 /* fill any remaining space in page with padding */ 70 #define _CP_PAD2_SZ P2ROUNDUP(NCPU, PAGESIZE / sizeof (hrtime_t)) - NCPU 71 uint64_t _cp_pad2[_CP_PAD2_SZ]; 72 #else 73 /* length resides in cp_tsc_ncpu */ 74 hrtime_t cp_tsc_sync_tick_delta[]; 75 #endif /* defined(_MACHDEP) */ 76 } comm_page_t; 77 78 #if defined(_KERNEL) 79 extern comm_page_t comm_page; 80 81 #if defined(_MACHDEP) 82 83 #include <sys/debug.h> 84 CTASSERT((offsetof(comm_page_t, cp_tsc_sync_tick_delta) & PAGEOFFSET) == 0); 85 CTASSERT((sizeof (comm_page_t) & PAGEOFFSET) == 0); 86 87 extern hrtime_t tsc_last; 88 extern hrtime_t tsc_hrtime_base; 89 extern hrtime_t tsc_resume_cap; 90 extern uint32_t tsc_type; 91 extern uint32_t tsc_max_delta; 92 extern volatile uint32_t hres_lock; 93 extern uint32_t nsec_scale; 94 extern int64_t hrestime_adj; 95 extern hrtime_t hres_last_tick; 96 extern uint32_t tsc_ncpu; 97 extern volatile timestruc_t hrestime; 98 extern hrtime_t tsc_sync_tick_delta[NCPU]; 99 100 #endif /* defined(_MACHDEP) */ 101 #endif /* defined(_KERNEL) */ 102 103 #endif /* _ASM */ 104 105 #ifdef __cplusplus 106 } 107 #endif 108 109 #endif /* _COMM_PAGE_H */ 110