aboutsummaryrefslogtreecommitdiffstats
path: root/litmus/litmus_proc.c
blob: 4bf725a36c9cddeeb795d4dd0915f2093b6b0ae1 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
/*
 * litmus_proc.c -- Implementation of the /proc/litmus directory tree.
 */

#include <linux/sched.h>
#include <linux/uaccess.h>

#include <litmus/litmus.h>
#include <litmus/litmus_proc.h>

#include <litmus/clustered.h>

/* in litmus/litmus.c */
extern atomic_t rt_task_count;

static struct proc_dir_entry *litmus_dir = NULL,
	*curr_file = NULL,
	*stat_file = NULL,
	*plugs_dir = NULL,
#ifdef CONFIG_RELEASE_MASTER
	*release_master_file = NULL,
#endif
	*plugs_file = NULL;

/* in litmus/sync.c */
int count_tasks_waiting_for_release(void);

static int proc_read_stats(char *page, char **start,
			   off_t off, int count,
			   int *eof, void *data)
{
	int len;

	len = snprintf(page, PAGE_SIZE,
		       "real-time tasks   = %d\n"
		       "ready for release = %d\n",
		       atomic_read(&rt_task_count),
		       count_tasks_waiting_for_release());
	return len;
}

static int proc_read_plugins(char *page, char **start,
			   off_t off, int count,
			   int *eof, void *data)
{
	int len;

	len = print_sched_plugins(page, PAGE_SIZE);
	return len;
}

static int proc_read_curr(char *page, char **start,
			  off_t off, int count,
			  int *eof, void *data)
{
	int len;

	len = snprintf(page, PAGE_SIZE, "%s\n", litmus->plugin_name);
	return len;
}

/* in litmus/litmus.c */
int switch_sched_plugin(struct sched_plugin*);

static int proc_write_curr(struct file *file,
			   const char *buffer,
			   unsigned long count,
			   void *data)
{
	int len, ret;
	char name[65];
	struct sched_plugin* found;

	len = copy_and_chomp(name, sizeof(name), buffer, count);
	if (len < 0)
		return len;

	found = find_sched_plugin(name);

	if (found) {
		ret = switch_sched_plugin(found);
		if (ret != 0)
			printk(KERN_INFO "Could not switch plugin: %d\n", ret);
	} else
		printk(KERN_INFO "Plugin '%s' is unknown.\n", name);

	return len;
}

#ifdef CONFIG_RELEASE_MASTER
static int proc_read_release_master(char *page, char **start,
				    off_t off, int count,
				    int *eof, void *data)
{
	int len, master;
	master = atomic_read(&release_master_cpu);
	if (master == NO_CPU)
		len = snprintf(page, PAGE_SIZE, "NO_CPU\n");
	else
		len = snprintf(page, PAGE_SIZE, "%d\n", master);
	return len;
}

static int proc_write_release_master(struct file *file,
				     const char *buffer,
				     unsigned long count,
				     void *data)
{
	int cpu, err, len, online = 0;
	char msg[64];

	len = copy_and_chomp(msg, sizeof(msg), buffer, count);

	if (len < 0)
		return len;

	if (strcmp(msg, "NO_CPU") == 0)
		atomic_set(&release_master_cpu, NO_CPU);
	else {
		err = sscanf(msg, "%d", &cpu);
		if (err == 1 && cpu >= 0 && (online = cpu_online(cpu))) {
			atomic_set(&release_master_cpu, cpu);
		} else {
			TRACE("invalid release master: '%s' "
			      "(err:%d cpu:%d online:%d)\n",
			      msg, err, cpu, online);
			len = -EINVAL;
		}
	}
	return len;
}
#endif

int __init init_litmus_proc(void)
{
	litmus_dir = proc_mkdir("litmus", NULL);
	if (!litmus_dir) {
		printk(KERN_ERR "Could not allocate LITMUS^RT procfs entry.\n");
		return -ENOMEM;
	}

	curr_file = create_proc_entry("active_plugin",
				      0644, litmus_dir);
	if (!curr_file) {
		printk(KERN_ERR "Could not allocate active_plugin "
		       "procfs entry.\n");
		return -ENOMEM;
	}
	curr_file->read_proc  = proc_read_curr;
	curr_file->write_proc = proc_write_curr;

#ifdef CONFIG_RELEASE_MASTER
	release_master_file = create_proc_entry("release_master",
						0644, litmus_dir);
	if (!release_master_file) {
		printk(KERN_ERR "Could not allocate release_master "
		       "procfs entry.\n");
		return -ENOMEM;
	}
	release_master_file->read_proc = proc_read_release_master;
	release_master_file->write_proc  = proc_write_release_master;
#endif

	stat_file = create_proc_read_entry("stats", 0444, litmus_dir,
					   proc_read_stats, NULL);

	plugs_dir = proc_mkdir("plugins", litmus_dir);
	if (!plugs_dir){
		printk(KERN_ERR "Could not allocate plugins directory "
				"procfs entry.\n");
		return -ENOMEM;
	}

	plugs_file = create_proc_read_entry("loaded", 0444, plugs_dir,
					   proc_read_plugins, NULL);

	return 0;
}

void exit_litmus_proc(void)
{
	if (plugs_file)
		remove_proc_entry("loaded", plugs_dir);
	if (plugs_dir)
		remove_proc_entry("plugins", litmus_dir);
	if (stat_file)
		remove_proc_entry("stats", litmus_dir);
	if (curr_file)
		remove_proc_entry("active_plugin", litmus_dir);
#ifdef CONFIG_RELEASE_MASTER
	if (release_master_file)
		remove_proc_entry("release_master", litmus_dir);
#endif
	if (litmus_dir)
		remove_proc_entry("litmus", NULL);
}

long make_plugin_proc_dir(struct sched_plugin* plugin,
		struct proc_dir_entry** pde_in)
{
	struct proc_dir_entry *pde_new = NULL;
	long rv;

	if (!plugin || !plugin->plugin_name){
		printk(KERN_ERR "Invalid plugin struct passed to %s.\n",
				__func__);
		rv = -EINVAL;
		goto out_no_pde;
	}

	if (!plugs_dir){
		printk(KERN_ERR "Could not make plugin sub-directory, because "
				"/proc/litmus/plugins does not exist.\n");
		rv = -ENOENT;
		goto out_no_pde;
	}

	pde_new = proc_mkdir(plugin->plugin_name, plugs_dir);
	if (!pde_new){
		printk(KERN_ERR "Could not make plugin sub-directory: "
				"out of memory?.\n");
		rv = -ENOMEM;
		goto out_no_pde;
	}

	rv = 0;
	*pde_in = pde_new;
	goto out_ok;

out_no_pde:
	*pde_in = NULL;
out_ok:
	return rv;
}

void remove_plugin_proc_dir(struct sched_plugin* plugin)
{
	if (!plugin || !plugin->plugin_name){
		printk(KERN_ERR "Invalid plugin struct passed to %s.\n",
				__func__);
		return;
	}
	remove_proc_entry(plugin->plugin_name, plugs_dir);
}



/* misc. I/O helper functions */

int copy_and_chomp(char *kbuf, unsigned long ksize,
		   __user const char* ubuf, unsigned long ulength)
{
	/* caller must provide buffer space */
	BUG_ON(!ksize);

	ksize--; /* leave space for null byte */

	if (ksize > ulength)
		ksize = ulength;

	if(copy_from_user(kbuf, ubuf, ksize))
		return -EFAULT;

	kbuf[ksize] = '\0';

	/* chomp kbuf */
	if (ksize > 0 && kbuf[ksize - 1] == '\n')
		kbuf[ksize - 1] = '\0';

	return ksize;
}

/* helper functions for clustered plugins */
static const char* cache_level_names[] = {
	"ALL",
	"L1",
	"L2",
	"L3",
};

int parse_cache_level(const char *cache_name, enum cache_level *level)
{
	int err = -EINVAL;
	int i;
	/* do a quick and dirty comparison to find the cluster size */
	for (i = GLOBAL_CLUSTER; i <= L3_CLUSTER; i++)
		if (!strcmp(cache_name, cache_level_names[i])) {
			*level = (enum cache_level) i;
			err = 0;
			break;
		}
	return err;
}

const char* cache_level_name(enum cache_level level)
{
	int idx = level;

	if (idx >= GLOBAL_CLUSTER && idx <= L3_CLUSTER)
		return cache_level_names[idx];
	else
		return "INVALID";
}


/* proc file interface to configure the cluster size */
static int proc_read_cluster_size(char *page, char **start,
				  off_t off, int count,
				  int *eof, void *data)
{
	return snprintf(page, PAGE_SIZE, "%s\n",
			cache_level_name(*((enum cache_level*) data)));;
}

static int proc_write_cluster_size(struct file *file,
				   const char *buffer,
				   unsigned long count,
				   void *data)
{
	int len;
	char cache_name[8];

	len = copy_and_chomp(cache_name, sizeof(cache_name), buffer, count);

	if (len > 0 && parse_cache_level(cache_name, (enum cache_level*) data))
		printk(KERN_INFO "Cluster '%s' is unknown.\n", cache_name);

	return len;
}

struct proc_dir_entry* create_cluster_file(struct proc_dir_entry* parent,
					   enum cache_level* level)
{
	struct proc_dir_entry* cluster_file;

	cluster_file = create_proc_entry("cluster", 0644, parent);
	if (!cluster_file) {
		printk(KERN_ERR "Could not allocate %s/cluster "
		       "procfs entry.\n", parent->name);
	} else {
		cluster_file->read_proc = proc_read_cluster_size;
		cluster_file->write_proc = proc_write_cluster_size;
		cluster_file->data = level;
	}
	return cluster_file;
}