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
6 * Copyright (C) 2004, 2005 MIPS Technologies, Inc. All rights reserved.
7 * Copyright (C) 2013 Imagination Technologies Ltd.
9 #include <linux/kernel.h>
10 #include <linux/device.h>
12 #include <linux/slab.h>
13 #include <linux/export.h>
15 #include <asm/mipsregs.h>
16 #include <asm/mipsmtregs.h>
17 #include <asm/mips_mt.h>
22 /* The number of TCs and VPEs physically available on the core */
23 static int hw_tcs, hw_vpes;
25 /* We are prepared so configure and start the VPE... */
26 int vpe_run(struct vpe *v)
28 unsigned long flags, val, dmt_flag;
29 struct vpe_notifications *notifier;
30 unsigned int vpeflags;
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);
46 if (list_empty(&v->tc)) {
49 local_irq_restore(flags);
51 pr_warn("VPE loader: No TC's associated with VPE %d\n",
57 t = list_first_entry(&v->tc, struct tc, tc);
59 /* Put MVPE's into 'configuration state' */
60 set_c0_mvpcontrol(MVPCONTROL_VPC);
64 /* should check it is halted, and not activated */
65 if ((read_tc_c0_tcstatus() & TCSTATUS_A) ||
66 !(read_tc_c0_tchalt() & TCHALT_H)) {
69 local_irq_restore(flags);
71 pr_warn("VPE loader: TC %d is already active!\n",
78 * Write the address we want it to start running from in the TCPC
81 write_tc_c0_tcrestart((unsigned long)v->__start);
82 write_tc_c0_tccontext((unsigned long)0);
85 * Mark the TC as activated, not interrupt exempt and not dynamically
88 val = read_tc_c0_tcstatus();
89 val = (val & ~(TCSTATUS_DA | TCSTATUS_IXMT)) | TCSTATUS_A;
90 write_tc_c0_tcstatus(val);
92 write_tc_c0_tchalt(read_tc_c0_tchalt() & ~TCHALT_H);
95 * We don't pass the memsize here, so VPE programs need to be
96 * compiled with DFLT_STACK_SIZE and DFLT_HEAP_SIZE defined.
103 * bind the TC to VPE 1 as late as possible so we only have the final
104 * VPE registers to set up, and so an EJTAG probe can trigger on it
106 write_tc_c0_tcbind((read_tc_c0_tcbind() & ~TCBIND_CURVPE) | 1);
108 write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~(VPECONF0_VPA));
110 back_to_back_c0_hazard();
112 /* Set up the XTC bit in vpeconf0 to point at our tc */
113 write_vpe_c0_vpeconf0((read_vpe_c0_vpeconf0() & ~(VPECONF0_XTC))
114 | (t->index << VPECONF0_XTC_SHIFT));
116 back_to_back_c0_hazard();
118 /* enable this VPE */
119 write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);
121 /* clear out any left overs from a previous program */
122 write_vpe_c0_status(0);
123 write_vpe_c0_cause(0);
125 /* take system out of configuration state */
126 clear_c0_mvpcontrol(MVPCONTROL_VPC);
129 * SMVP kernels manage VPE enable independently, but uniprocessor
130 * kernels need to turn it on, even if that wasn't the pre-dvpe() state.
138 local_irq_restore(flags);
140 list_for_each_entry(notifier, &v->notify, list)
141 notifier->start(VPE_MODULE_MINOR);
146 void cleanup_tc(struct tc *tc)
149 unsigned int mtflags, vpflags;
152 local_irq_save(flags);
155 /* Put MVPE's into 'configuration state' */
156 set_c0_mvpcontrol(MVPCONTROL_VPC);
159 tmp = read_tc_c0_tcstatus();
161 /* mark not allocated and not dynamically allocatable */
162 tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
163 tmp |= TCSTATUS_IXMT; /* interrupt exempt */
164 write_tc_c0_tcstatus(tmp);
166 write_tc_c0_tchalt(TCHALT_H);
169 clear_c0_mvpcontrol(MVPCONTROL_VPC);
172 local_irq_restore(flags);
175 /* module wrapper entry points */
177 void *vpe_alloc(void)
183 for (i = 1; i < MAX_VPES; i++) {
186 v->state = VPE_STATE_INUSE;
192 EXPORT_SYMBOL(vpe_alloc);
194 /* start running from here */
195 int vpe_start(void *vpe, unsigned long start)
202 EXPORT_SYMBOL(vpe_start);
204 /* halt it for now */
205 int vpe_stop(void *vpe)
209 unsigned int evpe_flags;
213 t = list_entry(v->tc.next, struct tc, tc);
216 write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA);
223 EXPORT_SYMBOL(vpe_stop);
225 /* I've done with it thank you */
226 int vpe_free(void *vpe)
230 unsigned int evpe_flags;
232 t = list_entry(v->tc.next, struct tc, tc);
238 /* Put MVPE's into 'configuration state' */
239 set_c0_mvpcontrol(MVPCONTROL_VPC);
242 write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA);
245 write_tc_c0_tchalt(TCHALT_H);
248 /* mark the TC unallocated */
249 write_tc_c0_tcstatus(read_tc_c0_tcstatus() & ~TCSTATUS_A);
251 v->state = VPE_STATE_UNUSED;
253 clear_c0_mvpcontrol(MVPCONTROL_VPC);
258 EXPORT_SYMBOL(vpe_free);
260 static ssize_t store_kill(struct device *dev, struct device_attribute *attr,
261 const char *buf, size_t len)
263 struct vpe *vpe = get_vpe(aprp_cpu_index());
264 struct vpe_notifications *notifier;
266 list_for_each_entry(notifier, &vpe->notify, list)
267 notifier->stop(aprp_cpu_index());
269 release_progmem(vpe->load_addr);
270 cleanup_tc(get_tc(aprp_cpu_index()));
276 static DEVICE_ATTR(kill, S_IWUSR, NULL, store_kill);
278 static ssize_t ntcs_show(struct device *cd, struct device_attribute *attr,
281 struct vpe *vpe = get_vpe(aprp_cpu_index());
283 return sprintf(buf, "%d\n", vpe->ntcs);
286 static ssize_t ntcs_store(struct device *dev, struct device_attribute *attr,
287 const char *buf, size_t len)
289 struct vpe *vpe = get_vpe(aprp_cpu_index());
293 ret = kstrtoul(buf, 0, &new);
297 if (new == 0 || new > (hw_tcs - aprp_cpu_index()))
304 static DEVICE_ATTR_RW(ntcs);
306 static struct attribute *vpe_attrs[] = {
311 ATTRIBUTE_GROUPS(vpe);
313 static void vpe_device_release(struct device *cd)
317 static struct class vpe_class = {
319 .owner = THIS_MODULE,
320 .dev_release = vpe_device_release,
321 .dev_groups = vpe_groups,
324 static struct device vpe_device;
326 int __init vpe_module_init(void)
328 unsigned int mtflags, vpflags;
329 unsigned long flags, val;
330 struct vpe *v = NULL;
334 if (!cpu_has_mipsmt) {
335 pr_warn("VPE loader: not a MIPS MT capable processor\n");
340 pr_warn("No VPEs reserved for AP/SP, not initialize VPE loader\n"
341 "Pass maxvpes=<n> argument as kernel argument\n");
346 if (aprp_cpu_index() == 0) {
347 pr_warn("No TCs reserved for AP/SP, not initialize VPE loader\n"
348 "Pass maxtcs=<n> argument as kernel argument\n");
353 major = register_chrdev(0, VPE_MODULE_NAME, &vpe_fops);
355 pr_warn("VPE loader: unable to register character device\n");
359 err = class_register(&vpe_class);
361 pr_err("vpe_class registration failed\n");
365 device_initialize(&vpe_device);
366 vpe_device.class = &vpe_class,
367 vpe_device.parent = NULL,
368 dev_set_name(&vpe_device, "vpe1");
369 vpe_device.devt = MKDEV(major, VPE_MODULE_MINOR);
370 err = device_add(&vpe_device);
372 pr_err("Adding vpe_device failed\n");
376 local_irq_save(flags);
380 /* Put MVPE's into 'configuration state' */
381 set_c0_mvpcontrol(MVPCONTROL_VPC);
383 val = read_c0_mvpconf0();
384 hw_tcs = (val & MVPCONF0_PTC) + 1;
385 hw_vpes = ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
387 for (tc = aprp_cpu_index(); tc < hw_tcs; tc++) {
389 * Must re-enable multithreading temporarily or in case we
390 * reschedule send IPIs or similar we might hang.
392 clear_c0_mvpcontrol(MVPCONTROL_VPC);
395 local_irq_restore(flags);
402 local_irq_save(flags);
405 set_c0_mvpcontrol(MVPCONTROL_VPC);
413 pr_warn("VPE: unable to allocate VPE\n");
417 v->ntcs = hw_tcs - aprp_cpu_index();
419 /* add the tc to the list of this vpe's tc's. */
420 list_add(&t->tc, &v->tc);
422 /* deactivate all but vpe0 */
423 if (tc >= aprp_cpu_index()) {
424 unsigned long tmp = read_vpe_c0_vpeconf0();
426 tmp &= ~VPECONF0_VPA;
430 write_vpe_c0_vpeconf0(tmp);
433 /* disable multi-threading with TC's */
434 write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() &
437 if (tc >= vpelimit) {
439 * Set config to be the same as vpe0,
440 * particularly kseg0 coherency alg
442 write_vpe_c0_config(read_c0_config());
447 t->pvpe = v; /* set the parent vpe */
449 if (tc >= aprp_cpu_index()) {
455 * A TC that is bound to any other VPE gets bound to
456 * VPE0, ideally I'd like to make it homeless but it
457 * doesn't appear to let me bind a TC to a non-existent
458 * VPE. Which is perfectly reasonable.
460 * The (un)bound state is visible to an EJTAG probe so
463 tmp = read_tc_c0_tcbind();
464 if (tmp & TCBIND_CURVPE) {
465 /* tc is bound >vpe0 */
466 write_tc_c0_tcbind(tmp & ~TCBIND_CURVPE);
468 t->pvpe = get_vpe(0); /* set the parent vpe */
472 write_tc_c0_tchalt(TCHALT_H);
475 tmp = read_tc_c0_tcstatus();
477 /* mark not activated and not dynamically allocatable */
478 tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
479 tmp |= TCSTATUS_IXMT; /* interrupt exempt */
480 write_tc_c0_tcstatus(tmp);
485 /* release config state */
486 clear_c0_mvpcontrol(MVPCONTROL_VPC);
490 local_irq_restore(flags);
495 device_del(&vpe_device);
498 put_device(&vpe_device);
499 class_unregister(&vpe_class);
502 unregister_chrdev(major, VPE_MODULE_NAME);
507 void __exit vpe_module_exit(void)
511 device_unregister(&vpe_device);
512 class_unregister(&vpe_class);
513 unregister_chrdev(major, VPE_MODULE_NAME);
515 /* No locking needed here */
516 list_for_each_entry_safe(v, n, &vpecontrol.vpe_list, list) {
517 if (v->state != VPE_STATE_UNUSED)