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1a2a6d7e DCZ |
1 | /* |
2 | * This file is subject to the terms and conditions of the GNU General Public | |
3 | * License. See the file "COPYING" in the main directory of this archive | |
4 | * for more details. | |
5 | * | |
6 | * Copyright (C) 2004, 2005 MIPS Technologies, Inc. All rights reserved. | |
7 | * Copyright (C) 2013 Imagination Technologies Ltd. | |
8 | */ | |
9 | #include <linux/kernel.h> | |
10 | #include <linux/device.h> | |
11 | #include <linux/fs.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/export.h> | |
14 | ||
15 | #include <asm/mipsregs.h> | |
16 | #include <asm/mipsmtregs.h> | |
17 | #include <asm/mips_mt.h> | |
18 | #include <asm/vpe.h> | |
19 | ||
20 | static int major; | |
21 | ||
22 | /* The number of TCs and VPEs physically available on the core */ | |
23 | static int hw_tcs, hw_vpes; | |
24 | ||
25 | /* We are prepared so configure and start the VPE... */ | |
26 | int vpe_run(struct vpe *v) | |
27 | { | |
28 | unsigned long flags, val, dmt_flag; | |
29 | struct vpe_notifications *n; | |
30 | unsigned int vpeflags; | |
31 | struct tc *t; | |
32 | ||
33 | /* check we are the Master VPE */ | |
34 | local_irq_save(flags); | |
35 | val = read_c0_vpeconf0(); | |
36 | if (!(val & VPECONF0_MVP)) { | |
37 | pr_warn("VPE loader: only Master VPE's are able to config MT\n"); | |
38 | local_irq_restore(flags); | |
39 | ||
40 | return -1; | |
41 | } | |
42 | ||
43 | dmt_flag = dmt(); | |
44 | vpeflags = dvpe(); | |
45 | ||
46 | if (list_empty(&v->tc)) { | |
47 | evpe(vpeflags); | |
48 | emt(dmt_flag); | |
49 | local_irq_restore(flags); | |
50 | ||
51 | pr_warn("VPE loader: No TC's associated with VPE %d\n", | |
52 | v->minor); | |
53 | ||
54 | return -ENOEXEC; | |
55 | } | |
56 | ||
57 | t = list_first_entry(&v->tc, struct tc, tc); | |
58 | ||
59 | /* Put MVPE's into 'configuration state' */ | |
60 | set_c0_mvpcontrol(MVPCONTROL_VPC); | |
61 | ||
62 | settc(t->index); | |
63 | ||
64 | /* should check it is halted, and not activated */ | |
65 | if ((read_tc_c0_tcstatus() & TCSTATUS_A) || | |
66 | !(read_tc_c0_tchalt() & TCHALT_H)) { | |
67 | evpe(vpeflags); | |
68 | emt(dmt_flag); | |
69 | local_irq_restore(flags); | |
70 | ||
71 | pr_warn("VPE loader: TC %d is already active!\n", | |
72 | t->index); | |
73 | ||
74 | return -ENOEXEC; | |
75 | } | |
76 | ||
77 | /* | |
78 | * Write the address we want it to start running from in the TCPC | |
79 | * register. | |
80 | */ | |
81 | write_tc_c0_tcrestart((unsigned long)v->__start); | |
82 | write_tc_c0_tccontext((unsigned long)0); | |
83 | ||
84 | /* | |
85 | * Mark the TC as activated, not interrupt exempt and not dynamically | |
86 | * allocatable | |
87 | */ | |
88 | val = read_tc_c0_tcstatus(); | |
89 | val = (val & ~(TCSTATUS_DA | TCSTATUS_IXMT)) | TCSTATUS_A; | |
90 | write_tc_c0_tcstatus(val); | |
91 | ||
92 | write_tc_c0_tchalt(read_tc_c0_tchalt() & ~TCHALT_H); | |
93 | ||
94 | /* | |
95 | * The sde-kit passes 'memsize' to __start in $a3, so set something | |
96 | * here... Or set $a3 to zero and define DFLT_STACK_SIZE and | |
97 | * DFLT_HEAP_SIZE when you compile your program | |
98 | */ | |
99 | mttgpr(6, v->ntcs); | |
100 | mttgpr(7, physical_memsize); | |
101 | ||
102 | /* set up VPE1 */ | |
103 | /* | |
104 | * bind the TC to VPE 1 as late as possible so we only have the final | |
105 | * VPE registers to set up, and so an EJTAG probe can trigger on it | |
106 | */ | |
107 | write_tc_c0_tcbind((read_tc_c0_tcbind() & ~TCBIND_CURVPE) | 1); | |
108 | ||
109 | write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~(VPECONF0_VPA)); | |
110 | ||
111 | back_to_back_c0_hazard(); | |
112 | ||
113 | /* Set up the XTC bit in vpeconf0 to point at our tc */ | |
114 | write_vpe_c0_vpeconf0((read_vpe_c0_vpeconf0() & ~(VPECONF0_XTC)) | |
115 | | (t->index << VPECONF0_XTC_SHIFT)); | |
116 | ||
117 | back_to_back_c0_hazard(); | |
118 | ||
119 | /* enable this VPE */ | |
120 | write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA); | |
121 | ||
122 | /* clear out any left overs from a previous program */ | |
123 | write_vpe_c0_status(0); | |
124 | write_vpe_c0_cause(0); | |
125 | ||
126 | /* take system out of configuration state */ | |
127 | clear_c0_mvpcontrol(MVPCONTROL_VPC); | |
128 | ||
129 | /* | |
130 | * SMTC/SMVP kernels manage VPE enable independently, | |
131 | * but uniprocessor kernels need to turn it on, even | |
132 | * if that wasn't the pre-dvpe() state. | |
133 | */ | |
134 | #ifdef CONFIG_SMP | |
135 | evpe(vpeflags); | |
136 | #else | |
137 | evpe(EVPE_ENABLE); | |
138 | #endif | |
139 | emt(dmt_flag); | |
140 | local_irq_restore(flags); | |
141 | ||
142 | list_for_each_entry(n, &v->notify, list) | |
143 | n->start(VPE_MODULE_MINOR); | |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
148 | void cleanup_tc(struct tc *tc) | |
149 | { | |
150 | unsigned long flags; | |
151 | unsigned int mtflags, vpflags; | |
152 | int tmp; | |
153 | ||
154 | local_irq_save(flags); | |
155 | mtflags = dmt(); | |
156 | vpflags = dvpe(); | |
157 | /* Put MVPE's into 'configuration state' */ | |
158 | set_c0_mvpcontrol(MVPCONTROL_VPC); | |
159 | ||
160 | settc(tc->index); | |
161 | tmp = read_tc_c0_tcstatus(); | |
162 | ||
163 | /* mark not allocated and not dynamically allocatable */ | |
164 | tmp &= ~(TCSTATUS_A | TCSTATUS_DA); | |
165 | tmp |= TCSTATUS_IXMT; /* interrupt exempt */ | |
166 | write_tc_c0_tcstatus(tmp); | |
167 | ||
168 | write_tc_c0_tchalt(TCHALT_H); | |
169 | mips_ihb(); | |
170 | ||
171 | clear_c0_mvpcontrol(MVPCONTROL_VPC); | |
172 | evpe(vpflags); | |
173 | emt(mtflags); | |
174 | local_irq_restore(flags); | |
175 | } | |
176 | ||
177 | /* module wrapper entry points */ | |
178 | /* give me a vpe */ | |
179 | void *vpe_alloc(void) | |
180 | { | |
181 | int i; | |
182 | struct vpe *v; | |
183 | ||
184 | /* find a vpe */ | |
185 | for (i = 1; i < MAX_VPES; i++) { | |
186 | v = get_vpe(i); | |
187 | if (v != NULL) { | |
188 | v->state = VPE_STATE_INUSE; | |
189 | return v; | |
190 | } | |
191 | } | |
192 | return NULL; | |
193 | } | |
194 | EXPORT_SYMBOL(vpe_alloc); | |
195 | ||
196 | /* start running from here */ | |
197 | int vpe_start(void *vpe, unsigned long start) | |
198 | { | |
199 | struct vpe *v = vpe; | |
200 | ||
201 | v->__start = start; | |
202 | return vpe_run(v); | |
203 | } | |
204 | EXPORT_SYMBOL(vpe_start); | |
205 | ||
206 | /* halt it for now */ | |
207 | int vpe_stop(void *vpe) | |
208 | { | |
209 | struct vpe *v = vpe; | |
210 | struct tc *t; | |
211 | unsigned int evpe_flags; | |
212 | ||
213 | evpe_flags = dvpe(); | |
214 | ||
215 | t = list_entry(v->tc.next, struct tc, tc); | |
216 | if (t != NULL) { | |
217 | settc(t->index); | |
218 | write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA); | |
219 | } | |
220 | ||
221 | evpe(evpe_flags); | |
222 | ||
223 | return 0; | |
224 | } | |
225 | EXPORT_SYMBOL(vpe_stop); | |
226 | ||
227 | /* I've done with it thank you */ | |
228 | int vpe_free(void *vpe) | |
229 | { | |
230 | struct vpe *v = vpe; | |
231 | struct tc *t; | |
232 | unsigned int evpe_flags; | |
233 | ||
234 | t = list_entry(v->tc.next, struct tc, tc); | |
235 | if (t == NULL) | |
236 | return -ENOEXEC; | |
237 | ||
238 | evpe_flags = dvpe(); | |
239 | ||
240 | /* Put MVPE's into 'configuration state' */ | |
241 | set_c0_mvpcontrol(MVPCONTROL_VPC); | |
242 | ||
243 | settc(t->index); | |
244 | write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA); | |
245 | ||
246 | /* halt the TC */ | |
247 | write_tc_c0_tchalt(TCHALT_H); | |
248 | mips_ihb(); | |
249 | ||
250 | /* mark the TC unallocated */ | |
251 | write_tc_c0_tcstatus(read_tc_c0_tcstatus() & ~TCSTATUS_A); | |
252 | ||
253 | v->state = VPE_STATE_UNUSED; | |
254 | ||
255 | clear_c0_mvpcontrol(MVPCONTROL_VPC); | |
256 | evpe(evpe_flags); | |
257 | ||
258 | return 0; | |
259 | } | |
260 | EXPORT_SYMBOL(vpe_free); | |
261 | ||
262 | static ssize_t store_kill(struct device *dev, struct device_attribute *attr, | |
263 | const char *buf, size_t len) | |
264 | { | |
265 | struct vpe *vpe = get_vpe(aprp_cpu_index()); | |
266 | struct vpe_notifications *notifier; | |
267 | ||
268 | list_for_each_entry(notifier, &vpe->notify, list) | |
269 | notifier->stop(aprp_cpu_index()); | |
270 | ||
271 | release_progmem(vpe->load_addr); | |
272 | cleanup_tc(get_tc(aprp_cpu_index())); | |
273 | vpe_stop(vpe); | |
274 | vpe_free(vpe); | |
275 | ||
276 | return len; | |
277 | } | |
278 | static DEVICE_ATTR(kill, S_IWUSR, NULL, store_kill); | |
279 | ||
280 | static ssize_t ntcs_show(struct device *cd, struct device_attribute *attr, | |
281 | char *buf) | |
282 | { | |
283 | struct vpe *vpe = get_vpe(aprp_cpu_index()); | |
284 | ||
285 | return sprintf(buf, "%d\n", vpe->ntcs); | |
286 | } | |
287 | ||
288 | static ssize_t ntcs_store(struct device *dev, struct device_attribute *attr, | |
289 | const char *buf, size_t len) | |
290 | { | |
291 | struct vpe *vpe = get_vpe(aprp_cpu_index()); | |
292 | unsigned long new; | |
293 | int ret; | |
294 | ||
295 | ret = kstrtoul(buf, 0, &new); | |
296 | if (ret < 0) | |
297 | return ret; | |
298 | ||
299 | if (new == 0 || new > (hw_tcs - aprp_cpu_index())) | |
300 | return -EINVAL; | |
301 | ||
302 | vpe->ntcs = new; | |
303 | ||
304 | return len; | |
305 | } | |
306 | static DEVICE_ATTR_RW(ntcs); | |
307 | ||
308 | static struct attribute *vpe_attrs[] = { | |
309 | &dev_attr_kill.attr, | |
310 | &dev_attr_ntcs.attr, | |
311 | NULL, | |
312 | }; | |
313 | ATTRIBUTE_GROUPS(vpe); | |
314 | ||
315 | static void vpe_device_release(struct device *cd) | |
316 | { | |
317 | kfree(cd); | |
318 | } | |
319 | ||
320 | static struct class vpe_class = { | |
321 | .name = "vpe", | |
322 | .owner = THIS_MODULE, | |
323 | .dev_release = vpe_device_release, | |
324 | .dev_groups = vpe_groups, | |
325 | }; | |
326 | ||
327 | static struct device vpe_device; | |
328 | ||
329 | int __init vpe_module_init(void) | |
330 | { | |
331 | unsigned int mtflags, vpflags; | |
332 | unsigned long flags, val; | |
333 | struct vpe *v = NULL; | |
334 | struct tc *t; | |
335 | int tc, err; | |
336 | ||
337 | if (!cpu_has_mipsmt) { | |
338 | pr_warn("VPE loader: not a MIPS MT capable processor\n"); | |
339 | return -ENODEV; | |
340 | } | |
341 | ||
342 | if (vpelimit == 0) { | |
343 | pr_warn("No VPEs reserved for AP/SP, not initialize VPE loader\n" | |
344 | "Pass maxvpes=<n> argument as kernel argument\n"); | |
345 | ||
346 | return -ENODEV; | |
347 | } | |
348 | ||
349 | if (aprp_cpu_index() == 0) { | |
350 | pr_warn("No TCs reserved for AP/SP, not initialize VPE loader\n" | |
351 | "Pass maxtcs=<n> argument as kernel argument\n"); | |
352 | ||
353 | return -ENODEV; | |
354 | } | |
355 | ||
356 | major = register_chrdev(0, VPE_MODULE_NAME, &vpe_fops); | |
357 | if (major < 0) { | |
358 | pr_warn("VPE loader: unable to register character device\n"); | |
359 | return major; | |
360 | } | |
361 | ||
362 | err = class_register(&vpe_class); | |
363 | if (err) { | |
364 | pr_err("vpe_class registration failed\n"); | |
365 | goto out_chrdev; | |
366 | } | |
367 | ||
368 | device_initialize(&vpe_device); | |
369 | vpe_device.class = &vpe_class, | |
370 | vpe_device.parent = NULL, | |
371 | dev_set_name(&vpe_device, "vpe1"); | |
372 | vpe_device.devt = MKDEV(major, VPE_MODULE_MINOR); | |
373 | err = device_add(&vpe_device); | |
374 | if (err) { | |
375 | pr_err("Adding vpe_device failed\n"); | |
376 | goto out_class; | |
377 | } | |
378 | ||
379 | local_irq_save(flags); | |
380 | mtflags = dmt(); | |
381 | vpflags = dvpe(); | |
382 | ||
383 | /* Put MVPE's into 'configuration state' */ | |
384 | set_c0_mvpcontrol(MVPCONTROL_VPC); | |
385 | ||
386 | val = read_c0_mvpconf0(); | |
387 | hw_tcs = (val & MVPCONF0_PTC) + 1; | |
388 | hw_vpes = ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1; | |
389 | ||
390 | for (tc = aprp_cpu_index(); tc < hw_tcs; tc++) { | |
391 | /* | |
392 | * Must re-enable multithreading temporarily or in case we | |
393 | * reschedule send IPIs or similar we might hang. | |
394 | */ | |
395 | clear_c0_mvpcontrol(MVPCONTROL_VPC); | |
396 | evpe(vpflags); | |
397 | emt(mtflags); | |
398 | local_irq_restore(flags); | |
399 | t = alloc_tc(tc); | |
400 | if (!t) { | |
401 | err = -ENOMEM; | |
402 | goto out_dev; | |
403 | } | |
404 | ||
405 | local_irq_save(flags); | |
406 | mtflags = dmt(); | |
407 | vpflags = dvpe(); | |
408 | set_c0_mvpcontrol(MVPCONTROL_VPC); | |
409 | ||
410 | /* VPE's */ | |
411 | if (tc < hw_tcs) { | |
412 | settc(tc); | |
413 | ||
414 | v = alloc_vpe(tc); | |
415 | if (v == NULL) { | |
416 | pr_warn("VPE: unable to allocate VPE\n"); | |
417 | goto out_reenable; | |
418 | } | |
419 | ||
420 | v->ntcs = hw_tcs - aprp_cpu_index(); | |
421 | ||
422 | /* add the tc to the list of this vpe's tc's. */ | |
423 | list_add(&t->tc, &v->tc); | |
424 | ||
425 | /* deactivate all but vpe0 */ | |
426 | if (tc >= aprp_cpu_index()) { | |
427 | unsigned long tmp = read_vpe_c0_vpeconf0(); | |
428 | ||
429 | tmp &= ~VPECONF0_VPA; | |
430 | ||
431 | /* master VPE */ | |
432 | tmp |= VPECONF0_MVP; | |
433 | write_vpe_c0_vpeconf0(tmp); | |
434 | } | |
435 | ||
436 | /* disable multi-threading with TC's */ | |
437 | write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & | |
438 | ~VPECONTROL_TE); | |
439 | ||
440 | if (tc >= vpelimit) { | |
441 | /* | |
442 | * Set config to be the same as vpe0, | |
443 | * particularly kseg0 coherency alg | |
444 | */ | |
445 | write_vpe_c0_config(read_c0_config()); | |
446 | } | |
447 | } | |
448 | ||
449 | /* TC's */ | |
450 | t->pvpe = v; /* set the parent vpe */ | |
451 | ||
452 | if (tc >= aprp_cpu_index()) { | |
453 | unsigned long tmp; | |
454 | ||
455 | settc(tc); | |
456 | ||
457 | /* Any TC that is bound to VPE0 gets left as is - in | |
458 | * case we are running SMTC on VPE0. A TC that is bound | |
459 | * to any other VPE gets bound to VPE0, ideally I'd like | |
460 | * to make it homeless but it doesn't appear to let me | |
461 | * bind a TC to a non-existent VPE. Which is perfectly | |
462 | * reasonable. | |
463 | * | |
464 | * The (un)bound state is visible to an EJTAG probe so | |
465 | * may notify GDB... | |
466 | */ | |
467 | tmp = read_tc_c0_tcbind(); | |
468 | if (tmp & TCBIND_CURVPE) { | |
469 | /* tc is bound >vpe0 */ | |
470 | write_tc_c0_tcbind(tmp & ~TCBIND_CURVPE); | |
471 | ||
472 | t->pvpe = get_vpe(0); /* set the parent vpe */ | |
473 | } | |
474 | ||
475 | /* halt the TC */ | |
476 | write_tc_c0_tchalt(TCHALT_H); | |
477 | mips_ihb(); | |
478 | ||
479 | tmp = read_tc_c0_tcstatus(); | |
480 | ||
481 | /* mark not activated and not dynamically allocatable */ | |
482 | tmp &= ~(TCSTATUS_A | TCSTATUS_DA); | |
483 | tmp |= TCSTATUS_IXMT; /* interrupt exempt */ | |
484 | write_tc_c0_tcstatus(tmp); | |
485 | } | |
486 | } | |
487 | ||
488 | out_reenable: | |
489 | /* release config state */ | |
490 | clear_c0_mvpcontrol(MVPCONTROL_VPC); | |
491 | ||
492 | evpe(vpflags); | |
493 | emt(mtflags); | |
494 | local_irq_restore(flags); | |
495 | ||
496 | return 0; | |
497 | ||
498 | out_dev: | |
499 | device_del(&vpe_device); | |
500 | ||
501 | out_class: | |
502 | class_unregister(&vpe_class); | |
503 | ||
504 | out_chrdev: | |
505 | unregister_chrdev(major, VPE_MODULE_NAME); | |
506 | ||
507 | return err; | |
508 | } | |
509 | ||
510 | void __exit vpe_module_exit(void) | |
511 | { | |
512 | struct vpe *v, *n; | |
513 | ||
514 | device_del(&vpe_device); | |
515 | class_unregister(&vpe_class); | |
516 | unregister_chrdev(major, VPE_MODULE_NAME); | |
517 | ||
518 | /* No locking needed here */ | |
519 | list_for_each_entry_safe(v, n, &vpecontrol.vpe_list, list) { | |
520 | if (v->state != VPE_STATE_UNUSED) | |
521 | release_vpe(v); | |
522 | } | |
523 | } |