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1/*
2 * Copyright (C) 2005 MIPS Technologies, Inc. All rights reserved.
3 *
4 * This program is free software; you can distribute it and/or modify it
5 * under the terms of the GNU General Public License (Version 2) as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * for more details.
12 *
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
16 *
17 */
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/sched.h>
21#include <linux/unistd.h>
22#include <linux/file.h>
23#include <linux/fdtable.h>
24#include <linux/fs.h>
25#include <linux/syscalls.h>
26#include <linux/workqueue.h>
27#include <linux/errno.h>
28#include <linux/list.h>
29
30#include <asm/vpe.h>
31#include <asm/rtlx.h>
32#include <asm/kspd.h>
33
34static struct workqueue_struct *workqueue;
35static struct work_struct work;
36
37extern unsigned long cpu_khz;
38
39struct mtsp_syscall {
40 int cmd;
41 unsigned char abi;
42 unsigned char size;
43};
44
45struct mtsp_syscall_ret {
46 int retval;
47 int errno;
48};
49
50struct mtsp_syscall_generic {
51 int arg0;
52 int arg1;
53 int arg2;
54 int arg3;
55 int arg4;
56 int arg5;
57 int arg6;
58};
59
60static struct list_head kspd_notifylist;
61static int sp_stopping;
62
63/* these should match with those in the SDE kit */
64#define MTSP_SYSCALL_BASE 0
65#define MTSP_SYSCALL_EXIT (MTSP_SYSCALL_BASE + 0)
66#define MTSP_SYSCALL_OPEN (MTSP_SYSCALL_BASE + 1)
67#define MTSP_SYSCALL_READ (MTSP_SYSCALL_BASE + 2)
68#define MTSP_SYSCALL_WRITE (MTSP_SYSCALL_BASE + 3)
69#define MTSP_SYSCALL_CLOSE (MTSP_SYSCALL_BASE + 4)
70#define MTSP_SYSCALL_LSEEK32 (MTSP_SYSCALL_BASE + 5)
71#define MTSP_SYSCALL_ISATTY (MTSP_SYSCALL_BASE + 6)
72#define MTSP_SYSCALL_GETTIME (MTSP_SYSCALL_BASE + 7)
73#define MTSP_SYSCALL_PIPEFREQ (MTSP_SYSCALL_BASE + 8)
74#define MTSP_SYSCALL_GETTOD (MTSP_SYSCALL_BASE + 9)
75#define MTSP_SYSCALL_IOCTL (MTSP_SYSCALL_BASE + 10)
76
77#define MTSP_O_RDONLY 0x0000
78#define MTSP_O_WRONLY 0x0001
79#define MTSP_O_RDWR 0x0002
80#define MTSP_O_NONBLOCK 0x0004
81#define MTSP_O_APPEND 0x0008
82#define MTSP_O_SHLOCK 0x0010
83#define MTSP_O_EXLOCK 0x0020
84#define MTSP_O_ASYNC 0x0040
85/* XXX: check which of these is actually O_SYNC vs O_DSYNC */
86#define MTSP_O_FSYNC O_SYNC
87#define MTSP_O_NOFOLLOW 0x0100
88#define MTSP_O_SYNC 0x0080
89#define MTSP_O_CREAT 0x0200
90#define MTSP_O_TRUNC 0x0400
91#define MTSP_O_EXCL 0x0800
92#define MTSP_O_BINARY 0x8000
93
94extern int tclimit;
95
96struct apsp_table {
97 int sp;
98 int ap;
99};
100
101/* we might want to do the mode flags too */
102struct apsp_table open_flags_table[] = {
103 { MTSP_O_RDWR, O_RDWR },
104 { MTSP_O_WRONLY, O_WRONLY },
105 { MTSP_O_CREAT, O_CREAT },
106 { MTSP_O_TRUNC, O_TRUNC },
107 { MTSP_O_NONBLOCK, O_NONBLOCK },
108 { MTSP_O_APPEND, O_APPEND },
109 { MTSP_O_NOFOLLOW, O_NOFOLLOW }
110};
111
112struct apsp_table syscall_command_table[] = {
113 { MTSP_SYSCALL_OPEN, __NR_open },
114 { MTSP_SYSCALL_CLOSE, __NR_close },
115 { MTSP_SYSCALL_READ, __NR_read },
116 { MTSP_SYSCALL_WRITE, __NR_write },
117 { MTSP_SYSCALL_LSEEK32, __NR_lseek },
118 { MTSP_SYSCALL_IOCTL, __NR_ioctl }
119};
120
121static int sp_syscall(int num, int arg0, int arg1, int arg2, int arg3)
122{
123 register long int _num __asm__("$2") = num;
124 register long int _arg0 __asm__("$4") = arg0;
125 register long int _arg1 __asm__("$5") = arg1;
126 register long int _arg2 __asm__("$6") = arg2;
127 register long int _arg3 __asm__("$7") = arg3;
128
129 mm_segment_t old_fs;
130
131 old_fs = get_fs();
132 set_fs(KERNEL_DS);
133
134 __asm__ __volatile__ (
135 " syscall \n"
136 : "=r" (_num), "=r" (_arg3)
137 : "r" (_num), "r" (_arg0), "r" (_arg1), "r" (_arg2), "r" (_arg3));
138
139 set_fs(old_fs);
140
141 /* $a3 is error flag */
142 if (_arg3)
143 return -_num;
144
145 return _num;
146}
147
148static int translate_syscall_command(int cmd)
149{
150 int i;
151 int ret = -1;
152
153 for (i = 0; i < ARRAY_SIZE(syscall_command_table); i++) {
154 if ((cmd == syscall_command_table[i].sp))
155 return syscall_command_table[i].ap;
156 }
157
158 return ret;
159}
160
161static unsigned int translate_open_flags(int flags)
162{
163 int i;
164 unsigned int ret = 0;
165
166 for (i = 0; i < ARRAY_SIZE(open_flags_table); i++) {
167 if( (flags & open_flags_table[i].sp) ) {
168 ret |= open_flags_table[i].ap;
169 }
170 }
171
172 return ret;
173}
174
175
176static int sp_setfsuidgid(uid_t uid, gid_t gid)
177{
178 struct cred *new;
179
180 new = prepare_creds();
181 if (!new)
182 return -ENOMEM;
183
184 new->fsuid = uid;
185 new->fsgid = gid;
186
187 commit_creds(new);
188
189 return 0;
190}
191
192/*
193 * Expects a request to be on the sysio channel. Reads it. Decides whether
194 * its a linux syscall and runs it, or whatever. Puts the return code back
195 * into the request and sends the whole thing back.
196 */
197void sp_work_handle_request(void)
198{
199 struct mtsp_syscall sc;
200 struct mtsp_syscall_generic generic;
201 struct mtsp_syscall_ret ret;
202 struct kspd_notifications *n;
203 unsigned long written;
204 mm_segment_t old_fs;
205 struct timeval tv;
206 struct timezone tz;
207 int err, cmd;
208
209 char *vcwd;
210 int size;
211
212 ret.retval = -1;
213
214 old_fs = get_fs();
215 set_fs(KERNEL_DS);
216
217 if (!rtlx_read(RTLX_CHANNEL_SYSIO, &sc, sizeof(struct mtsp_syscall))) {
218 set_fs(old_fs);
219 printk(KERN_ERR "Expected request but nothing to read\n");
220 return;
221 }
222
223 size = sc.size;
224
225 if (size) {
226 if (!rtlx_read(RTLX_CHANNEL_SYSIO, &generic, size)) {
227 set_fs(old_fs);
228 printk(KERN_ERR "Expected request but nothing to read\n");
229 return;
230 }
231 }
232
233 /* Run the syscall at the privilege of the user who loaded the
234 SP program */
235
236 if (vpe_getuid(tclimit)) {
237 err = sp_setfsuidgid(vpe_getuid(tclimit), vpe_getgid(tclimit));
238 if (!err)
239 pr_err("Change of creds failed\n");
240 }
241
242 switch (sc.cmd) {
243 /* needs the flags argument translating from SDE kit to
244 linux */
245 case MTSP_SYSCALL_PIPEFREQ:
246 ret.retval = cpu_khz * 1000;
247 ret.errno = 0;
248 break;
249
250 case MTSP_SYSCALL_GETTOD:
251 memset(&tz, 0, sizeof(tz));
252 if ((ret.retval = sp_syscall(__NR_gettimeofday, (int)&tv,
253 (int)&tz, 0, 0)) == 0)
254 ret.retval = tv.tv_sec;
255 break;
256
257 case MTSP_SYSCALL_EXIT:
258 list_for_each_entry(n, &kspd_notifylist, list)
259 n->kspd_sp_exit(tclimit);
260 sp_stopping = 1;
261
262 printk(KERN_DEBUG "KSPD got exit syscall from SP exitcode %d\n",
263 generic.arg0);
264 break;
265
266 case MTSP_SYSCALL_OPEN:
267 generic.arg1 = translate_open_flags(generic.arg1);
268
269 vcwd = vpe_getcwd(tclimit);
270
271 /* change to cwd of the process that loaded the SP program */
272 old_fs = get_fs();
273 set_fs(KERNEL_DS);
274 sys_chdir(vcwd);
275 set_fs(old_fs);
276
277 sc.cmd = __NR_open;
278
279 /* fall through */
280
281 default:
282 if ((sc.cmd >= __NR_Linux) &&
283 (sc.cmd <= (__NR_Linux + __NR_Linux_syscalls)) )
284 cmd = sc.cmd;
285 else
286 cmd = translate_syscall_command(sc.cmd);
287
288 if (cmd >= 0) {
289 ret.retval = sp_syscall(cmd, generic.arg0, generic.arg1,
290 generic.arg2, generic.arg3);
291 } else
292 printk(KERN_WARNING
293 "KSPD: Unknown SP syscall number %d\n", sc.cmd);
294 break;
295 } /* switch */
296
297 if (vpe_getuid(tclimit)) {
298 err = sp_setfsuidgid(0, 0);
299 if (!err)
300 pr_err("restoring old creds failed\n");
301 }
302
303 old_fs = get_fs();
304 set_fs(KERNEL_DS);
305 written = rtlx_write(RTLX_CHANNEL_SYSIO, &ret, sizeof(ret));
306 set_fs(old_fs);
307 if (written < sizeof(ret))
308 printk("KSPD: sp_work_handle_request failed to send to SP\n");
309}
310
311static void sp_cleanup(void)
312{
313 struct files_struct *files = current->files;
314 int i, j;
315 struct fdtable *fdt;
316
317 j = 0;
318
319 /*
320 * It is safe to dereference the fd table without RCU or
321 * ->file_lock
322 */
323 fdt = files_fdtable(files);
324 for (;;) {
325 unsigned long set;
326 i = j * __NFDBITS;
327 if (i >= fdt->max_fds)
328 break;
329 set = fdt->open_fds->fds_bits[j++];
330 while (set) {
331 if (set & 1) {
332 struct file * file = xchg(&fdt->fd[i], NULL);
333 if (file)
334 filp_close(file, files);
335 }
336 i++;
337 set >>= 1;
338 }
339 }
340
341 /* Put daemon cwd back to root to avoid umount problems */
342 sys_chdir("/");
343}
344
345static int channel_open;
346
347/* the work handler */
348static void sp_work(struct work_struct *unused)
349{
350 if (!channel_open) {
351 if( rtlx_open(RTLX_CHANNEL_SYSIO, 1) != 0) {
352 printk("KSPD: unable to open sp channel\n");
353 sp_stopping = 1;
354 } else {
355 channel_open++;
356 printk(KERN_DEBUG "KSPD: SP channel opened\n");
357 }
358 } else {
359 /* wait for some data, allow it to sleep */
360 rtlx_read_poll(RTLX_CHANNEL_SYSIO, 1);
361
362 /* Check we haven't been woken because we are stopping */
363 if (!sp_stopping)
364 sp_work_handle_request();
365 }
366
367 if (!sp_stopping)
368 queue_work(workqueue, &work);
369 else
370 sp_cleanup();
371}
372
373static void startwork(int vpe)
374{
375 sp_stopping = channel_open = 0;
376
377 if (workqueue == NULL) {
378 if ((workqueue = create_singlethread_workqueue("kspd")) == NULL) {
379 printk(KERN_ERR "unable to start kspd\n");
380 return;
381 }
382
383 INIT_WORK(&work, sp_work);
384 }
385
386 queue_work(workqueue, &work);
387}
388
389static void stopwork(int vpe)
390{
391 sp_stopping = 1;
392
393 printk(KERN_DEBUG "KSPD: SP stopping\n");
394}
395
396void kspd_notify(struct kspd_notifications *notify)
397{
398 list_add(¬ify->list, &kspd_notifylist);
399}
400
401static struct vpe_notifications notify;
402static int kspd_module_init(void)
403{
404 INIT_LIST_HEAD(&kspd_notifylist);
405
406 notify.start = startwork;
407 notify.stop = stopwork;
408 vpe_notify(tclimit, ¬ify);
409
410 return 0;
411}
412
413static void kspd_module_exit(void)
414{
415
416}
417
418module_init(kspd_module_init);
419module_exit(kspd_module_exit);
420
421MODULE_DESCRIPTION("MIPS KSPD");
422MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
423MODULE_LICENSE("GPL");