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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; | |
5792bf64 | 29 | struct vpe_notifications *notifier; |
1a2a6d7e DCZ |
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 | /* | |
b633648c RB |
130 | * SMVP kernels manage VPE enable independently, but uniprocessor |
131 | * kernels need to turn it on, even if that wasn't the pre-dvpe() state. | |
1a2a6d7e DCZ |
132 | */ |
133 | #ifdef CONFIG_SMP | |
134 | evpe(vpeflags); | |
135 | #else | |
136 | evpe(EVPE_ENABLE); | |
137 | #endif | |
138 | emt(dmt_flag); | |
139 | local_irq_restore(flags); | |
140 | ||
5792bf64 SH |
141 | list_for_each_entry(notifier, &v->notify, list) |
142 | notifier->start(VPE_MODULE_MINOR); | |
1a2a6d7e DCZ |
143 | |
144 | return 0; | |
145 | } | |
146 | ||
147 | void cleanup_tc(struct tc *tc) | |
148 | { | |
149 | unsigned long flags; | |
150 | unsigned int mtflags, vpflags; | |
151 | int tmp; | |
152 | ||
153 | local_irq_save(flags); | |
154 | mtflags = dmt(); | |
155 | vpflags = dvpe(); | |
156 | /* Put MVPE's into 'configuration state' */ | |
157 | set_c0_mvpcontrol(MVPCONTROL_VPC); | |
158 | ||
159 | settc(tc->index); | |
160 | tmp = read_tc_c0_tcstatus(); | |
161 | ||
162 | /* mark not allocated and not dynamically allocatable */ | |
163 | tmp &= ~(TCSTATUS_A | TCSTATUS_DA); | |
164 | tmp |= TCSTATUS_IXMT; /* interrupt exempt */ | |
165 | write_tc_c0_tcstatus(tmp); | |
166 | ||
167 | write_tc_c0_tchalt(TCHALT_H); | |
168 | mips_ihb(); | |
169 | ||
170 | clear_c0_mvpcontrol(MVPCONTROL_VPC); | |
171 | evpe(vpflags); | |
172 | emt(mtflags); | |
173 | local_irq_restore(flags); | |
174 | } | |
175 | ||
176 | /* module wrapper entry points */ | |
177 | /* give me a vpe */ | |
178 | void *vpe_alloc(void) | |
179 | { | |
180 | int i; | |
181 | struct vpe *v; | |
182 | ||
183 | /* find a vpe */ | |
184 | for (i = 1; i < MAX_VPES; i++) { | |
185 | v = get_vpe(i); | |
186 | if (v != NULL) { | |
187 | v->state = VPE_STATE_INUSE; | |
188 | return v; | |
189 | } | |
190 | } | |
191 | return NULL; | |
192 | } | |
193 | EXPORT_SYMBOL(vpe_alloc); | |
194 | ||
195 | /* start running from here */ | |
196 | int vpe_start(void *vpe, unsigned long start) | |
197 | { | |
198 | struct vpe *v = vpe; | |
199 | ||
200 | v->__start = start; | |
201 | return vpe_run(v); | |
202 | } | |
203 | EXPORT_SYMBOL(vpe_start); | |
204 | ||
205 | /* halt it for now */ | |
206 | int vpe_stop(void *vpe) | |
207 | { | |
208 | struct vpe *v = vpe; | |
209 | struct tc *t; | |
210 | unsigned int evpe_flags; | |
211 | ||
212 | evpe_flags = dvpe(); | |
213 | ||
214 | t = list_entry(v->tc.next, struct tc, tc); | |
215 | if (t != NULL) { | |
216 | settc(t->index); | |
217 | write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA); | |
218 | } | |
219 | ||
220 | evpe(evpe_flags); | |
221 | ||
222 | return 0; | |
223 | } | |
224 | EXPORT_SYMBOL(vpe_stop); | |
225 | ||
226 | /* I've done with it thank you */ | |
227 | int vpe_free(void *vpe) | |
228 | { | |
229 | struct vpe *v = vpe; | |
230 | struct tc *t; | |
231 | unsigned int evpe_flags; | |
232 | ||
233 | t = list_entry(v->tc.next, struct tc, tc); | |
234 | if (t == NULL) | |
235 | return -ENOEXEC; | |
236 | ||
237 | evpe_flags = dvpe(); | |
238 | ||
239 | /* Put MVPE's into 'configuration state' */ | |
240 | set_c0_mvpcontrol(MVPCONTROL_VPC); | |
241 | ||
242 | settc(t->index); | |
243 | write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA); | |
244 | ||
245 | /* halt the TC */ | |
246 | write_tc_c0_tchalt(TCHALT_H); | |
247 | mips_ihb(); | |
248 | ||
249 | /* mark the TC unallocated */ | |
250 | write_tc_c0_tcstatus(read_tc_c0_tcstatus() & ~TCSTATUS_A); | |
251 | ||
252 | v->state = VPE_STATE_UNUSED; | |
253 | ||
254 | clear_c0_mvpcontrol(MVPCONTROL_VPC); | |
255 | evpe(evpe_flags); | |
256 | ||
257 | return 0; | |
258 | } | |
259 | EXPORT_SYMBOL(vpe_free); | |
260 | ||
261 | static ssize_t store_kill(struct device *dev, struct device_attribute *attr, | |
262 | const char *buf, size_t len) | |
263 | { | |
264 | struct vpe *vpe = get_vpe(aprp_cpu_index()); | |
265 | struct vpe_notifications *notifier; | |
266 | ||
267 | list_for_each_entry(notifier, &vpe->notify, list) | |
268 | notifier->stop(aprp_cpu_index()); | |
269 | ||
270 | release_progmem(vpe->load_addr); | |
271 | cleanup_tc(get_tc(aprp_cpu_index())); | |
272 | vpe_stop(vpe); | |
273 | vpe_free(vpe); | |
274 | ||
275 | return len; | |
276 | } | |
277 | static DEVICE_ATTR(kill, S_IWUSR, NULL, store_kill); | |
278 | ||
279 | static ssize_t ntcs_show(struct device *cd, struct device_attribute *attr, | |
280 | char *buf) | |
281 | { | |
282 | struct vpe *vpe = get_vpe(aprp_cpu_index()); | |
283 | ||
284 | return sprintf(buf, "%d\n", vpe->ntcs); | |
285 | } | |
286 | ||
287 | static ssize_t ntcs_store(struct device *dev, struct device_attribute *attr, | |
288 | const char *buf, size_t len) | |
289 | { | |
290 | struct vpe *vpe = get_vpe(aprp_cpu_index()); | |
291 | unsigned long new; | |
292 | int ret; | |
293 | ||
294 | ret = kstrtoul(buf, 0, &new); | |
295 | if (ret < 0) | |
296 | return ret; | |
297 | ||
298 | if (new == 0 || new > (hw_tcs - aprp_cpu_index())) | |
299 | return -EINVAL; | |
300 | ||
301 | vpe->ntcs = new; | |
302 | ||
303 | return len; | |
304 | } | |
305 | static DEVICE_ATTR_RW(ntcs); | |
306 | ||
307 | static struct attribute *vpe_attrs[] = { | |
308 | &dev_attr_kill.attr, | |
309 | &dev_attr_ntcs.attr, | |
310 | NULL, | |
311 | }; | |
312 | ATTRIBUTE_GROUPS(vpe); | |
313 | ||
314 | static void vpe_device_release(struct device *cd) | |
315 | { | |
316 | kfree(cd); | |
317 | } | |
318 | ||
319 | static struct class vpe_class = { | |
320 | .name = "vpe", | |
321 | .owner = THIS_MODULE, | |
322 | .dev_release = vpe_device_release, | |
323 | .dev_groups = vpe_groups, | |
324 | }; | |
325 | ||
326 | static struct device vpe_device; | |
327 | ||
328 | int __init vpe_module_init(void) | |
329 | { | |
330 | unsigned int mtflags, vpflags; | |
331 | unsigned long flags, val; | |
332 | struct vpe *v = NULL; | |
333 | struct tc *t; | |
334 | int tc, err; | |
335 | ||
336 | if (!cpu_has_mipsmt) { | |
337 | pr_warn("VPE loader: not a MIPS MT capable processor\n"); | |
338 | return -ENODEV; | |
339 | } | |
340 | ||
341 | if (vpelimit == 0) { | |
342 | pr_warn("No VPEs reserved for AP/SP, not initialize VPE loader\n" | |
343 | "Pass maxvpes=<n> argument as kernel argument\n"); | |
344 | ||
345 | return -ENODEV; | |
346 | } | |
347 | ||
348 | if (aprp_cpu_index() == 0) { | |
349 | pr_warn("No TCs reserved for AP/SP, not initialize VPE loader\n" | |
350 | "Pass maxtcs=<n> argument as kernel argument\n"); | |
351 | ||
352 | return -ENODEV; | |
353 | } | |
354 | ||
355 | major = register_chrdev(0, VPE_MODULE_NAME, &vpe_fops); | |
356 | if (major < 0) { | |
357 | pr_warn("VPE loader: unable to register character device\n"); | |
358 | return major; | |
359 | } | |
360 | ||
361 | err = class_register(&vpe_class); | |
362 | if (err) { | |
363 | pr_err("vpe_class registration failed\n"); | |
364 | goto out_chrdev; | |
365 | } | |
366 | ||
367 | device_initialize(&vpe_device); | |
368 | vpe_device.class = &vpe_class, | |
369 | vpe_device.parent = NULL, | |
370 | dev_set_name(&vpe_device, "vpe1"); | |
371 | vpe_device.devt = MKDEV(major, VPE_MODULE_MINOR); | |
372 | err = device_add(&vpe_device); | |
373 | if (err) { | |
374 | pr_err("Adding vpe_device failed\n"); | |
375 | goto out_class; | |
376 | } | |
377 | ||
378 | local_irq_save(flags); | |
379 | mtflags = dmt(); | |
380 | vpflags = dvpe(); | |
381 | ||
382 | /* Put MVPE's into 'configuration state' */ | |
383 | set_c0_mvpcontrol(MVPCONTROL_VPC); | |
384 | ||
385 | val = read_c0_mvpconf0(); | |
386 | hw_tcs = (val & MVPCONF0_PTC) + 1; | |
387 | hw_vpes = ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1; | |
388 | ||
389 | for (tc = aprp_cpu_index(); tc < hw_tcs; tc++) { | |
390 | /* | |
391 | * Must re-enable multithreading temporarily or in case we | |
392 | * reschedule send IPIs or similar we might hang. | |
393 | */ | |
394 | clear_c0_mvpcontrol(MVPCONTROL_VPC); | |
395 | evpe(vpflags); | |
396 | emt(mtflags); | |
397 | local_irq_restore(flags); | |
398 | t = alloc_tc(tc); | |
399 | if (!t) { | |
400 | err = -ENOMEM; | |
401 | goto out_dev; | |
402 | } | |
403 | ||
404 | local_irq_save(flags); | |
405 | mtflags = dmt(); | |
406 | vpflags = dvpe(); | |
407 | set_c0_mvpcontrol(MVPCONTROL_VPC); | |
408 | ||
409 | /* VPE's */ | |
410 | if (tc < hw_tcs) { | |
411 | settc(tc); | |
412 | ||
413 | v = alloc_vpe(tc); | |
414 | if (v == NULL) { | |
415 | pr_warn("VPE: unable to allocate VPE\n"); | |
416 | goto out_reenable; | |
417 | } | |
418 | ||
419 | v->ntcs = hw_tcs - aprp_cpu_index(); | |
420 | ||
421 | /* add the tc to the list of this vpe's tc's. */ | |
422 | list_add(&t->tc, &v->tc); | |
423 | ||
424 | /* deactivate all but vpe0 */ | |
425 | if (tc >= aprp_cpu_index()) { | |
426 | unsigned long tmp = read_vpe_c0_vpeconf0(); | |
427 | ||
428 | tmp &= ~VPECONF0_VPA; | |
429 | ||
430 | /* master VPE */ | |
431 | tmp |= VPECONF0_MVP; | |
432 | write_vpe_c0_vpeconf0(tmp); | |
433 | } | |
434 | ||
435 | /* disable multi-threading with TC's */ | |
436 | write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & | |
437 | ~VPECONTROL_TE); | |
438 | ||
439 | if (tc >= vpelimit) { | |
440 | /* | |
441 | * Set config to be the same as vpe0, | |
442 | * particularly kseg0 coherency alg | |
443 | */ | |
444 | write_vpe_c0_config(read_c0_config()); | |
445 | } | |
446 | } | |
447 | ||
448 | /* TC's */ | |
449 | t->pvpe = v; /* set the parent vpe */ | |
450 | ||
451 | if (tc >= aprp_cpu_index()) { | |
452 | unsigned long tmp; | |
453 | ||
454 | settc(tc); | |
455 | ||
b633648c RB |
456 | /* |
457 | * A TC that is bound to any other VPE gets bound to | |
458 | * VPE0, ideally I'd like to make it homeless but it | |
459 | * doesn't appear to let me bind a TC to a non-existent | |
460 | * VPE. Which is perfectly reasonable. | |
1a2a6d7e DCZ |
461 | * |
462 | * The (un)bound state is visible to an EJTAG probe so | |
463 | * may notify GDB... | |
464 | */ | |
465 | tmp = read_tc_c0_tcbind(); | |
466 | if (tmp & TCBIND_CURVPE) { | |
467 | /* tc is bound >vpe0 */ | |
468 | write_tc_c0_tcbind(tmp & ~TCBIND_CURVPE); | |
469 | ||
470 | t->pvpe = get_vpe(0); /* set the parent vpe */ | |
471 | } | |
472 | ||
473 | /* halt the TC */ | |
474 | write_tc_c0_tchalt(TCHALT_H); | |
475 | mips_ihb(); | |
476 | ||
477 | tmp = read_tc_c0_tcstatus(); | |
478 | ||
479 | /* mark not activated and not dynamically allocatable */ | |
480 | tmp &= ~(TCSTATUS_A | TCSTATUS_DA); | |
481 | tmp |= TCSTATUS_IXMT; /* interrupt exempt */ | |
482 | write_tc_c0_tcstatus(tmp); | |
483 | } | |
484 | } | |
485 | ||
486 | out_reenable: | |
487 | /* release config state */ | |
488 | clear_c0_mvpcontrol(MVPCONTROL_VPC); | |
489 | ||
490 | evpe(vpflags); | |
491 | emt(mtflags); | |
492 | local_irq_restore(flags); | |
493 | ||
494 | return 0; | |
495 | ||
496 | out_dev: | |
497 | device_del(&vpe_device); | |
498 | ||
499 | out_class: | |
500 | class_unregister(&vpe_class); | |
501 | ||
502 | out_chrdev: | |
503 | unregister_chrdev(major, VPE_MODULE_NAME); | |
504 | ||
505 | return err; | |
506 | } | |
507 | ||
508 | void __exit vpe_module_exit(void) | |
509 | { | |
510 | struct vpe *v, *n; | |
511 | ||
512 | device_del(&vpe_device); | |
513 | class_unregister(&vpe_class); | |
514 | unregister_chrdev(major, VPE_MODULE_NAME); | |
515 | ||
516 | /* No locking needed here */ | |
517 | list_for_each_entry_safe(v, n, &vpecontrol.vpe_list, list) { | |
518 | if (v->state != VPE_STATE_UNUSED) | |
519 | release_vpe(v); | |
520 | } | |
521 | } |