| 1 | /* |
| 2 | * Copyright (C) 2008 - Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca) |
| 3 | * |
| 4 | * This library is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU Lesser General Public |
| 6 | * License as published by the Free Software Foundation; either |
| 7 | * version 2.1 of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * This library is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | * Lesser General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU Lesser General Public |
| 15 | * License along with this library; if not, write to the Free Software |
| 16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 17 | */ |
| 18 | |
| 19 | #ifndef UST_HEADER_INLINE_H |
| 20 | #define UST_HEADER_INLINE_H |
| 21 | |
| 22 | #include <ust/core.h> |
| 23 | |
| 24 | /* |
| 25 | * ust_get_header_size |
| 26 | * |
| 27 | * Calculate alignment offset to 32-bits. This is the alignment offset of the |
| 28 | * event header. |
| 29 | * |
| 30 | * Important note : |
| 31 | * The event header must be 32-bits. The total offset calculated here : |
| 32 | * |
| 33 | * Alignment of header struct on 32 bits (min arch size, header size) |
| 34 | * + sizeof(header struct) (32-bits) |
| 35 | * + (opt) u16 (ext. event id) |
| 36 | * + (opt) u16 (event_size) (if event_size == 0xFFFFUL, has ext. event size) |
| 37 | * + (opt) u32 (ext. event size) |
| 38 | * + (opt) u64 full TSC (aligned on min(64-bits, arch size)) |
| 39 | * |
| 40 | * The payload must itself determine its own alignment from the biggest type it |
| 41 | * contains. |
| 42 | * */ |
| 43 | static __inline__ unsigned char ust_get_header_size( |
| 44 | struct ust_channel *channel, |
| 45 | size_t offset, |
| 46 | size_t data_size, |
| 47 | size_t *before_hdr_pad, |
| 48 | unsigned int rflags) |
| 49 | { |
| 50 | size_t orig_offset = offset; |
| 51 | size_t padding; |
| 52 | |
| 53 | padding = ltt_align(offset, sizeof(struct ltt_event_header)); |
| 54 | offset += padding; |
| 55 | offset += sizeof(struct ltt_event_header); |
| 56 | |
| 57 | if(unlikely(rflags)) { |
| 58 | switch (rflags) { |
| 59 | case LTT_RFLAG_ID_SIZE_TSC: |
| 60 | offset += sizeof(u16) + sizeof(u16); |
| 61 | if (data_size >= 0xFFFFU) |
| 62 | offset += sizeof(u32); |
| 63 | offset += ltt_align(offset, sizeof(u64)); |
| 64 | offset += sizeof(u64); |
| 65 | break; |
| 66 | case LTT_RFLAG_ID_SIZE: |
| 67 | offset += sizeof(u16) + sizeof(u16); |
| 68 | if (data_size >= 0xFFFFU) |
| 69 | offset += sizeof(u32); |
| 70 | break; |
| 71 | case LTT_RFLAG_ID: |
| 72 | offset += sizeof(u16); |
| 73 | break; |
| 74 | } |
| 75 | } |
| 76 | |
| 77 | *before_hdr_pad = padding; |
| 78 | return offset - orig_offset; |
| 79 | } |
| 80 | |
| 81 | #endif /* UST_HEADER_INLINE_H */ |