devtime.c revision 1068:6330fe678283 
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#ifdef __alpha__
52static int memTest = 0;
53#endif
54
55static inline uint32_t cycleCounter(uint32_t dep);
56
57static int __init devtime_start(void)
58{
59    uint64_t addr;
60    uint32_t t1, t2;
61    uint32_t trash;
62    int x;
63    uint32_t *times;
64    uint32_t num = 0;
65    struct net_device *dev;
66
67    printk("Devtime Driver Version %s Loaded...\n", DRIVER_VER);
68
69#ifdef __alpha__
70    if (memTest) {
71           addr = 0xfffffc0000000000;
72//         addr += 16*1024*1024;
73
74            printk("Preparing memory test.\n");
75
76            t1 = cycleCounter(trash);
77            for (x = 0; x < count; x++) {
78                trash = readl(addr);
79                t2 = cycleCounter(trash);
80                times[num++] = t2 - t1;
81                t1 = t2;
82               addr += 4096;
83            }
84
85            printk("Measurements:\n");
86            for (x = 0; x < count; x++) {
87                printk("%d ", times[x]);
88                if (((x + 1) % 10) == 0)
89                    printk("\n");
90            }
91            printk("\nDone.\n");
92    } else
93#endif
94    if (dataAddr != 0 && count != 0) {
95        addr = simple_strtoull(dataAddr, NULL, 0);
96
97        addr = ioremap(addr, PAGE_SIZE);
98        /**
99         * Make sure that the remapping actually worked. On alpha we have
100         * linear addressing, so its not a problem. But it can fail in x86
101         * if physical memory is mapped to this address.
102         */
103        times = kmalloc(sizeof(uint32_t) * count, GFP_USER);
104        if (!times) {
105            printk("Could not allocate memory... Try again later.\n");
106            return -1;
107        }
108
109        if (addr) {
110            printk("Preparing to read %#llx %d times.\n", addr, count);
111
112            t1 = cycleCounter(trash);
113            for (x = 0; x < count; x++) {
114                trash = readl(addr);
115                t2 = cycleCounter(trash);
116                times[num++] = t2 - t1;
117                t1 = t2;
118            }
119
120            /**
121             * Unmap the address.
122             */
123            iounmap(addr);
124
125            printk("Measurements:\n");
126            for (x = 0; x < count; x++) {
127                printk("%d ", times[x]);
128                if (((x + 1) % 10) == 0)
129                    printk("\n");
130            }
131            printk("\nDone.\n");
132        } else {
133            printk("Unable to remap address. Please try again later.\n");
134        }
135    } else {
136        dev = dev_get_by_name("eth0");
137        if (dev) {
138            printk("Eth0: MemStart: %#lx MemEnd: %#lx I/O Addr: %#lx\n",
139                   dev->mem_start, dev->mem_end, dev->base_addr);
140            dev_put(dev);
141        }
142        dev = 0;
143        dev = dev_get_by_name("eth1");
144        if (dev) {
145            printk("Eth1: MemStart: %#lx MemEnd: %#lx I/O Addr: %#lx\n",
146                   dev->mem_start, dev->mem_end, dev->base_addr);
147            dev_put(dev);
148        }
149
150        printk("Required information not supplied.\n");
151    }
152
153    return 0;
154}
155
156#ifdef __i386__
157
158static inline uint32_t cycleCounter(uint32_t dep)
159{
160    uint32_t time;
161    cpuid_eax(0);
162    rdtscl(time);
163    cpuid_eax(0);
164    return time;
165}
166
167#elif __alpha__
168
169inline uint32_t cycleCounter(uint32_t dep)
170{
171    uint32_t res;
172    asm volatile ("rpcc %0, %1" : "=r"(res) : "r" (dep) : "memory");
173    return res;
174}
175#else
176#error Architecture NOT SUPPORTED
177#endif
178
179static void __exit devtime_end(void)
180{
181    printk("Devtime Driver Version %s Unloaded...\n", DRIVER_VER);
182}
183
184
185module_init(devtime_start);
186module_exit(devtime_end);
187
188MODULE_LICENSE("Dual BSD/GPL");
189MODULE_AUTHOR(DRIVER_AUTHOR);
190MODULE_DESCRIPTION(DRIVER_DESC);
191module_param(dataAddr, charp, 0);
192module_param(count, int, 0);
193#ifdef __alpha__
194module_param(memTest, int, 0);
195#endif
196