devtime.c revision 2665:a124942bacb8 
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 * Authors: Ali Saidi
29 */
30
31#include <linux/module.h>
32#include <linux/config.h>
33#include <linux/moduleparam.h>
34#include <linux/init.h>
35#include <linux/fs.h>
36#include <asm/uaccess.h>
37#include <linux/kernel.h>
38#include <asm/io.h>
39#include <asm/page.h>
40#include <linux/netdevice.h>
41
42#ifdef __i386__
43#include <asm/processor.h>
44#include <asm/msr.h>
45#endif
46
47#define DRIVER_AUTHOR "Ali Saidi"
48#define DRIVER_DESC   "Interface to time uncacachable read and writes to device registers"
49#define DRIVER_VER    "0.1"
50
51static char *dataAddr = NULL;
52static int count = 0;
53#ifdef __alpha__
54static int memTest = 0;
55#endif
56
57static inline uint32_t cycleCounter(uint32_t dep);
58
59static int __init devtime_start(void)
60{
61    uint64_t addr;
62    uint32_t t1, t2;
63    uint32_t trash;
64    int x;
65    uint32_t *times;
66    uint32_t num = 0;
67    struct net_device *dev;
68
69    printk("Devtime Driver Version %s Loaded...\n", DRIVER_VER);
70
71#ifdef __alpha__
72    if (memTest) {
73           addr = 0xfffffc0000000000;
74//         addr += 16*1024*1024;
75
76            printk("Preparing memory test.\n");
77
78            t1 = cycleCounter(trash);
79            for (x = 0; x < count; x++) {
80                trash = readl(addr);
81                t2 = cycleCounter(trash);
82                times[num++] = t2 - t1;
83                t1 = t2;
84               addr += 4096;
85            }
86
87            printk("Measurements:\n");
88            for (x = 0; x < count; x++) {
89                printk("%d ", times[x]);
90                if (((x + 1) % 10) == 0)
91                    printk("\n");
92            }
93            printk("\nDone.\n");
94    } else
95#endif
96    if (dataAddr != 0 && count != 0) {
97        addr = simple_strtoull(dataAddr, NULL, 0);
98
99        addr = ioremap(addr, PAGE_SIZE);
100        /**
101         * Make sure that the remapping actually worked. On alpha we have
102         * linear addressing, so its not a problem. But it can fail in x86
103         * if physical memory is mapped to this address.
104         */
105        times = kmalloc(sizeof(uint32_t) * count, GFP_USER);
106        if (!times) {
107            printk("Could not allocate memory... Try again later.\n");
108            return -1;
109        }
110
111        if (addr) {
112            printk("Preparing to read %#llx %d times.\n", addr, count);
113
114            t1 = cycleCounter(trash);
115            for (x = 0; x < count; x++) {
116                trash = readl(addr);
117                t2 = cycleCounter(trash);
118                times[num++] = t2 - t1;
119                t1 = t2;
120            }
121
122            /**
123             * Unmap the address.
124             */
125            iounmap(addr);
126
127            printk("Measurements:\n");
128            for (x = 0; x < count; x++) {
129                printk("%d ", times[x]);
130                if (((x + 1) % 10) == 0)
131                    printk("\n");
132            }
133            printk("\nDone.\n");
134        } else {
135            printk("Unable to remap address. Please try again later.\n");
136        }
137    } else {
138        dev = dev_get_by_name("eth0");
139        if (dev) {
140            printk("Eth0: MemStart: %#lx MemEnd: %#lx I/O Addr: %#lx\n",
141                   dev->mem_start, dev->mem_end, dev->base_addr);
142            dev_put(dev);
143        }
144        dev = 0;
145        dev = dev_get_by_name("eth1");
146        if (dev) {
147            printk("Eth1: MemStart: %#lx MemEnd: %#lx I/O Addr: %#lx\n",
148                   dev->mem_start, dev->mem_end, dev->base_addr);
149            dev_put(dev);
150        }
151
152        printk("Required information not supplied.\n");
153    }
154
155    return 0;
156}
157
158#ifdef __i386__
159
160static inline uint32_t cycleCounter(uint32_t dep)
161{
162    uint32_t time;
163    cpuid_eax(0);
164    rdtscl(time);
165    cpuid_eax(0);
166    return time;
167}
168
169#elif __alpha__
170
171inline uint32_t cycleCounter(uint32_t dep)
172{
173    uint32_t res;
174    asm volatile ("rpcc %0, %1" : "=r"(res) : "r" (dep) : "memory");
175    return res;
176}
177#else
178#error Architecture NOT SUPPORTED
179#endif
180
181static void __exit devtime_end(void)
182{
183    printk("Devtime Driver Version %s Unloaded...\n", DRIVER_VER);
184}
185
186
187module_init(devtime_start);
188module_exit(devtime_end);
189
190MODULE_LICENSE("Dual BSD/GPL");
191MODULE_AUTHOR(DRIVER_AUTHOR);
192MODULE_DESCRIPTION(DRIVER_DESC);
193module_param(dataAddr, charp, 0);
194module_param(count, int, 0);
195#ifdef __alpha__
196module_param(memTest, int, 0);
197#endif
198