devtime.c revision 1051:d71e55bdc654
1/* 2 * Copyright (c) 2004 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29#include <linux/module.h> 30#include <linux/config.h> 31#include <linux/moduleparam.h> 32#include <linux/init.h> 33#include <linux/fs.h> 34#include <asm/uaccess.h> 35#include <linux/kernel.h> 36#include <asm/io.h> 37#include <asm/page.h> 38#include <linux/netdevice.h> 39 40#ifdef __i386__ 41#include <asm/processor.h> 42#include <asm/msr.h> 43#endif 44 45#define DRIVER_AUTHOR "Ali Saidi" 46#define DRIVER_DESC "Interface to time uncacachable read and writes to device registers" 47#define DRIVER_VER "0.1" 48 49static char *dataAddr = NULL; 50static int count = 0; 51 52static inline uint32_t cycleCounter(uint32_t dep); 53 54static int __init devtime_start(void) 55{ 56 uint64_t addr; 57 uint32_t t1, t2; 58 uint32_t trash; 59 int x; 60 uint32_t *times; 61 uint32_t num = 0; 62 struct net_device *dev; 63 64 65 printk("Devtime Driver Version %s Loaded...\n", DRIVER_VER); 66 67 if ((dataAddr != 0) && (count != 0)) 68 { 69 addr = simple_strtoull(dataAddr, NULL, 0); 70 71 addr = ioremap(addr, PAGE_SIZE); 72 /** 73 * Make sure that the remapping actually worked. On alpha we have 74 * linear addressing, so its not a problem. But it can fail in x86 75 * if physical memory is mapped to this address. 76 */ 77 times = kmalloc(sizeof(uint32_t) * count, GFP_USER); 78 if (!times) 79 { 80 printk("Could not allocate memory... Try again later.\n"); 81 return -1; 82 } 83 84 if (addr) 85 { 86 printk("Preparing to read %#llx %d times.\n", addr, count); 87 88 t1 = cycleCounter(trash); 89 for (x=0; x < count; x++) 90 { 91 trash = readl(addr); 92 t2 = cycleCounter(trash); 93 times[num++] = t2 - t1; 94 t1 = t2; 95 } 96 97 /** 98 * Unmap the address. 99 */ 100 iounmap(addr); 101 102 printk("Measurements:\n"); 103 for (x = 0; x < count; x++) 104 { 105 printk("%d ", times[x]); 106 if (((x+1) % 10) == 0) 107 printk("\n"); 108 } 109 printk("\nDone.\n"); 110 111 112 } 113 else 114 printk("Unable to remap address. Please try again later.\n"); 115 } else { 116 dev = dev_get_by_name("eth0"); 117 if (dev) 118 { 119 printk("Eth0: MemStart: %#lx MemEnd: %#lx I/O Addr: %#lx\n", dev->mem_start, 120 dev->mem_end, dev->base_addr); 121 dev_put(dev); 122 } 123 dev = 0; 124 dev = dev_get_by_name("eth1"); 125 if (dev) 126 { 127 printk("Eth1: MemStart: %#lx MemEnd: %#lx I/O Addr: %#lx\n", dev->mem_start, 128 dev->mem_end, dev->base_addr); 129 dev_put(dev); 130 } 131 132 133 printk("Required information not supplied.\n"); 134 } 135 136 return 0; 137} 138 139#ifdef __i386__ 140 141static inline uint32_t cycleCounter(uint32_t dep) 142{ 143 uint32_t time; 144 cpuid_eax(0); 145 rdtscl(time); 146 cpuid_eax(0); 147 return time; 148} 149 150#elif __alpha__ 151 152inline uint32_t cycleCounter(uint32_t dep) 153{ 154 uint32_t res; 155 asm volatile ("rpcc %0, %1" : "=r"(res) : "r" (dep) : "memory"); 156 return res; 157} 158#else 159#error Architecture NOT SUPPORTE 160#endif 161 162static void __exit devtime_end(void) { 163 printk("Devtime Driver Version %s Unloaded...\n", DRIVER_VER); 164} 165 166 167module_init(devtime_start); 168module_exit(devtime_end); 169 170MODULE_LICENSE("Dual BSD/GPL"); 171MODULE_AUTHOR(DRIVER_AUTHOR); 172MODULE_DESCRIPTION(DRIVER_DESC); 173module_param(dataAddr, charp, 0); 174module_param(count, int, 0); 175