| 1 | /* |
| 2 | * ========== Copyright Header Begin ========================================== |
| 3 | * |
| 4 | * OpenSPARC T2 Processor File: vtracer_async_queue.h |
| 5 | * Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved. |
| 6 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES. |
| 7 | * |
| 8 | * The above named program is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU General Public |
| 10 | * License version 2 as published by the Free Software Foundation. |
| 11 | * |
| 12 | * The above named program is distributed in the hope that it will be |
| 13 | * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public |
| 18 | * License along with this work; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. |
| 20 | * |
| 21 | * ========== Copyright Header End ============================================ |
| 22 | */ |
| 23 | //////////////////////////////////////////////////////////// |
| 24 | // |
| 25 | // File: vtracer_async_queue.h |
| 26 | // |
| 27 | // Copyright (C) 2001-2006 Sun Microsystems, Inc. |
| 28 | // All rights reserved. |
| 29 | // |
| 30 | |
| 31 | |
| 32 | // re-entrant queue structure for devices to send dma's, strings etc to the tracer |
| 33 | // this is the interface between blaze, the vcpu and devices (not relevant to tracer) |
| 34 | |
| 35 | // use dd if=/dev/random | od -XN 8 to get the random suffix |
| 36 | #ifndef _vtracer_async_queue_h_8b214547ac275755_ |
| 37 | #define _vtracer_async_queue_h_8b214547ac275755_ |
| 38 | |
| 39 | class vtracer_async_queue_el { |
| 40 | public: |
| 41 | |
| 42 | vtracer_async_queue_el(const union vtracer_async_data_u * arg_data) { |
| 43 | memcpy(&data, arg_data, sizeof(union vtracer_async_data_u)); |
| 44 | next = NULL; |
| 45 | } |
| 46 | |
| 47 | union vtracer_async_data_u data; |
| 48 | vtracer_async_queue_el * next; |
| 49 | }; // struct vtracer_async_queue_el |
| 50 | |
| 51 | |
| 52 | class vtracer_async_queue { |
| 53 | |
| 54 | public: |
| 55 | vtracer_async_queue() { |
| 56 | mutex_init(&mu, NULL, NULL); |
| 57 | head = tail = NULL; |
| 58 | qsize = 0; |
| 59 | } |
| 60 | |
| 61 | // for fast, non-locking "single reader" use |
| 62 | // example: if (trace_async_queue->getsize()) { dequeue(...); if (rtype_DMA) vtracer->dma(...); } |
| 63 | // this avoids the lock/unlock operations when the queue is empty, which is the common case |
| 64 | int getsize() { |
| 65 | return qsize; |
| 66 | } |
| 67 | |
| 68 | // use dequeue() in conjunction with getsize() for fast single-reader use |
| 69 | // if multiple threads wish to dequeue, they must call mt_dequeue() instead of getsize() and dequeue() |
| 70 | |
| 71 | // WARNING: precondition: head != NULL. must enforce by calling is_empty before calling dequeue |
| 72 | // WARNING: only one thread can "own" the queue - ie call is_empty() and dequeue(). |
| 73 | void dequeue(vtracer_async_data_u * data) { |
| 74 | volatile vtracer_async_queue_el * el = head; |
| 75 | |
| 76 | mutex_lock(&mu); |
| 77 | head = el->next; |
| 78 | if (head == NULL) tail = NULL; |
| 79 | qsize --; |
| 80 | mutex_unlock(&mu); |
| 81 | |
| 82 | memcpy((void *) data, (void *) &el->data, sizeof(vtracer_async_data_u)); |
| 83 | delete el; |
| 84 | } // void dequeue(int &iswrite, uint64_t &paddr, int64_t &nbytes) |
| 85 | |
| 86 | |
| 87 | // enqueue is called by (multiple) writer threads to add async records |
| 88 | void enqueue(vtracer_async_data_u * data) { |
| 89 | vtracer_async_queue_el * el = new vtracer_async_queue_el(data); |
| 90 | |
| 91 | mutex_lock(&mu); |
| 92 | if (tail != NULL) { |
| 93 | tail->next = el; |
| 94 | } else { |
| 95 | head = el; |
| 96 | } |
| 97 | tail = el; |
| 98 | qsize ++; |
| 99 | mutex_unlock(&mu); |
| 100 | |
| 101 | } // void enqueue(int iswrite, uint64_t paddr, int64_t nbytes) |
| 102 | |
| 103 | |
| 104 | // mt_dequeue atomically checks if the async queue is empty and dequeues the head if non-empty. |
| 105 | // Use it if multiple threads want to read out of the queue. |
| 106 | // Returns zero if queue was empty, positive otherwise. The number of records remaining is (return_value-1) or 0 if empty |
| 107 | // |
| 108 | // example: if (mt_dequeue(...)) if (dma) vtracer->dma(...); etc |
| 109 | int mt_dequeue(vtracer_async_data_u * data) { |
| 110 | mutex_lock(&mu); |
| 111 | int rv = qsize; |
| 112 | if (qsize) { |
| 113 | volatile vtracer_async_queue_el * el = head; |
| 114 | head = el->next; |
| 115 | if (head == NULL) tail = NULL; |
| 116 | qsize--; |
| 117 | memcpy((void *) data, (void *) &el->data, sizeof(vtracer_async_data_u)); |
| 118 | delete el; |
| 119 | } |
| 120 | mutex_unlock(&mu); |
| 121 | return rv; |
| 122 | } // int mt_dequeue(vtracer_async_data_u * data) |
| 123 | |
| 124 | private: |
| 125 | mutex_t mu; |
| 126 | |
| 127 | volatile int qsize; |
| 128 | volatile vtracer_async_queue_el * head; |
| 129 | volatile vtracer_async_queue_el * tail; |
| 130 | }; // class vtracer_async_queue |
| 131 | |
| 132 | // this is instantiated elsewhere in blaze initialization code |
| 133 | extern vtracer_async_queue * trace_async_queue; |
| 134 | |
| 135 | #define TRACE_DMA(TD_iswrite, TD_nbytes, TD_pa, TD_devid) \ |
| 136 | if (g_vcpu[g_vcpu_id_max]->config.trace_on) { \ |
| 137 | vtracer_async_data_u ad = {0}; \ |
| 138 | ad.dma.rtype = vtracer_async_data_u::rtype_DMA; \ |
| 139 | ad.dma.iswrite = TD_iswrite; \ |
| 140 | ad.dma.nbytes = TD_nbytes; \ |
| 141 | ad.dma.pa = TD_pa; \ |
| 142 | ad.dma.devid = TD_devid; \ |
| 143 | trace_async_queue->enqueue(&ad); \ |
| 144 | } |
| 145 | |
| 146 | |
| 147 | #endif // _vtracer_async_queue_h_8b214547ac275755_ |