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1/* linux/arch/sparc/kernel/process.c
2 *
3 * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
4 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
5 */
6
7/*
8 * This file handles the architecture-dependent parts of process handling..
9 */
10
11#include <stdarg.h>
12
13#include <linux/elfcore.h>
14#include <linux/errno.h>
15#include <linux/module.h>
16#include <linux/sched.h>
17#include <linux/kernel.h>
18#include <linux/mm.h>
19#include <linux/stddef.h>
20#include <linux/ptrace.h>
21#include <linux/user.h>
22#include <linux/smp.h>
23#include <linux/reboot.h>
24#include <linux/delay.h>
25#include <linux/pm.h>
26#include <linux/slab.h>
27#include <linux/cpu.h>
28
29#include <asm/auxio.h>
30#include <asm/oplib.h>
31#include <asm/uaccess.h>
32#include <asm/page.h>
33#include <asm/pgalloc.h>
34#include <asm/pgtable.h>
35#include <asm/delay.h>
36#include <asm/processor.h>
37#include <asm/psr.h>
38#include <asm/elf.h>
39#include <asm/prom.h>
40#include <asm/unistd.h>
41#include <asm/setup.h>
42
43#include "kernel.h"
44
45/*
46 * Power management idle function
47 * Set in pm platform drivers (apc.c and pmc.c)
48 */
49void (*sparc_idle)(void);
50
51/*
52 * Power-off handler instantiation for pm.h compliance
53 * This is done via auxio, but could be used as a fallback
54 * handler when auxio is not present-- unused for now...
55 */
56void (*pm_power_off)(void) = machine_power_off;
57EXPORT_SYMBOL(pm_power_off);
58
59/*
60 * sysctl - toggle power-off restriction for serial console
61 * systems in machine_power_off()
62 */
63int scons_pwroff = 1;
64
65extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
66
67struct task_struct *last_task_used_math = NULL;
68struct thread_info *current_set[NR_CPUS];
69
70/* Idle loop support. */
71void arch_cpu_idle(void)
72{
73 if (sparc_idle)
74 (*sparc_idle)();
75 local_irq_enable();
76}
77
78/* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
79void machine_halt(void)
80{
81 local_irq_enable();
82 mdelay(8);
83 local_irq_disable();
84 prom_halt();
85 panic("Halt failed!");
86}
87
88void machine_restart(char * cmd)
89{
90 char *p;
91
92 local_irq_enable();
93 mdelay(8);
94 local_irq_disable();
95
96 p = strchr (reboot_command, '\n');
97 if (p) *p = 0;
98 if (cmd)
99 prom_reboot(cmd);
100 if (*reboot_command)
101 prom_reboot(reboot_command);
102 prom_feval ("reset");
103 panic("Reboot failed!");
104}
105
106void machine_power_off(void)
107{
108 if (auxio_power_register &&
109 (strcmp(of_console_device->type, "serial") || scons_pwroff)) {
110 u8 power_register = sbus_readb(auxio_power_register);
111 power_register |= AUXIO_POWER_OFF;
112 sbus_writeb(power_register, auxio_power_register);
113 }
114
115 machine_halt();
116}
117
118void show_regs(struct pt_regs *r)
119{
120 struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14];
121
122 show_regs_print_info(KERN_DEFAULT);
123
124 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
125 r->psr, r->pc, r->npc, r->y, print_tainted());
126 printk("PC: <%pS>\n", (void *) r->pc);
127 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
128 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
129 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
130 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
131 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
132 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
133 printk("RPC: <%pS>\n", (void *) r->u_regs[15]);
134
135 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
136 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
137 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
138 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
139 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
140 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
141}
142
143/*
144 * The show_stack is an external API which we do not use ourselves.
145 * The oops is printed in die_if_kernel.
146 */
147void show_stack(struct task_struct *tsk, unsigned long *_ksp)
148{
149 unsigned long pc, fp;
150 unsigned long task_base;
151 struct reg_window32 *rw;
152 int count = 0;
153
154 if (!tsk)
155 tsk = current;
156
157 if (tsk == current && !_ksp)
158 __asm__ __volatile__("mov %%fp, %0" : "=r" (_ksp));
159
160 task_base = (unsigned long) task_stack_page(tsk);
161 fp = (unsigned long) _ksp;
162 do {
163 /* Bogus frame pointer? */
164 if (fp < (task_base + sizeof(struct thread_info)) ||
165 fp >= (task_base + (PAGE_SIZE << 1)))
166 break;
167 rw = (struct reg_window32 *) fp;
168 pc = rw->ins[7];
169 printk("[%08lx : ", pc);
170 printk("%pS ] ", (void *) pc);
171 fp = rw->ins[6];
172 } while (++count < 16);
173 printk("\n");
174}
175
176/*
177 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
178 */
179unsigned long thread_saved_pc(struct task_struct *tsk)
180{
181 return task_thread_info(tsk)->kpc;
182}
183
184/*
185 * Free current thread data structures etc..
186 */
187void exit_thread(void)
188{
189#ifndef CONFIG_SMP
190 if(last_task_used_math == current) {
191#else
192 if (test_thread_flag(TIF_USEDFPU)) {
193#endif
194 /* Keep process from leaving FPU in a bogon state. */
195 put_psr(get_psr() | PSR_EF);
196 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
197 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
198#ifndef CONFIG_SMP
199 last_task_used_math = NULL;
200#else
201 clear_thread_flag(TIF_USEDFPU);
202#endif
203 }
204}
205
206void flush_thread(void)
207{
208 current_thread_info()->w_saved = 0;
209
210#ifndef CONFIG_SMP
211 if(last_task_used_math == current) {
212#else
213 if (test_thread_flag(TIF_USEDFPU)) {
214#endif
215 /* Clean the fpu. */
216 put_psr(get_psr() | PSR_EF);
217 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
218 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
219#ifndef CONFIG_SMP
220 last_task_used_math = NULL;
221#else
222 clear_thread_flag(TIF_USEDFPU);
223#endif
224 }
225
226 /* This task is no longer a kernel thread. */
227 if (current->thread.flags & SPARC_FLAG_KTHREAD) {
228 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
229
230 /* We must fixup kregs as well. */
231 /* XXX This was not fixed for ti for a while, worked. Unused? */
232 current->thread.kregs = (struct pt_regs *)
233 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ));
234 }
235}
236
237static inline struct sparc_stackf __user *
238clone_stackframe(struct sparc_stackf __user *dst,
239 struct sparc_stackf __user *src)
240{
241 unsigned long size, fp;
242 struct sparc_stackf *tmp;
243 struct sparc_stackf __user *sp;
244
245 if (get_user(tmp, &src->fp))
246 return NULL;
247
248 fp = (unsigned long) tmp;
249 size = (fp - ((unsigned long) src));
250 fp = (unsigned long) dst;
251 sp = (struct sparc_stackf __user *)(fp - size);
252
253 /* do_fork() grabs the parent semaphore, we must release it
254 * temporarily so we can build the child clone stack frame
255 * without deadlocking.
256 */
257 if (__copy_user(sp, src, size))
258 sp = NULL;
259 else if (put_user(fp, &sp->fp))
260 sp = NULL;
261
262 return sp;
263}
264
265asmlinkage int sparc_do_fork(unsigned long clone_flags,
266 unsigned long stack_start,
267 struct pt_regs *regs,
268 unsigned long stack_size)
269{
270 unsigned long parent_tid_ptr, child_tid_ptr;
271 unsigned long orig_i1 = regs->u_regs[UREG_I1];
272 long ret;
273
274 parent_tid_ptr = regs->u_regs[UREG_I2];
275 child_tid_ptr = regs->u_regs[UREG_I4];
276
277 ret = do_fork(clone_flags, stack_start, stack_size,
278 (int __user *) parent_tid_ptr,
279 (int __user *) child_tid_ptr);
280
281 /* If we get an error and potentially restart the system
282 * call, we're screwed because copy_thread() clobbered
283 * the parent's %o1. So detect that case and restore it
284 * here.
285 */
286 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
287 regs->u_regs[UREG_I1] = orig_i1;
288
289 return ret;
290}
291
292/* Copy a Sparc thread. The fork() return value conventions
293 * under SunOS are nothing short of bletcherous:
294 * Parent --> %o0 == childs pid, %o1 == 0
295 * Child --> %o0 == parents pid, %o1 == 1
296 *
297 * NOTE: We have a separate fork kpsr/kwim because
298 * the parent could change these values between
299 * sys_fork invocation and when we reach here
300 * if the parent should sleep while trying to
301 * allocate the task_struct and kernel stack in
302 * do_fork().
303 * XXX See comment above sys_vfork in sparc64. todo.
304 */
305extern void ret_from_fork(void);
306extern void ret_from_kernel_thread(void);
307
308int copy_thread(unsigned long clone_flags, unsigned long sp,
309 unsigned long arg, struct task_struct *p)
310{
311 struct thread_info *ti = task_thread_info(p);
312 struct pt_regs *childregs, *regs = current_pt_regs();
313 char *new_stack;
314
315#ifndef CONFIG_SMP
316 if(last_task_used_math == current) {
317#else
318 if (test_thread_flag(TIF_USEDFPU)) {
319#endif
320 put_psr(get_psr() | PSR_EF);
321 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
322 &p->thread.fpqueue[0], &p->thread.fpqdepth);
323 }
324
325 /*
326 * p->thread_info new_stack childregs stack bottom
327 * ! ! ! !
328 * V V (stk.fr.) V (pt_regs) V
329 * +----- - - - - - ------+===========+=============+
330 */
331 new_stack = task_stack_page(p) + THREAD_SIZE;
332 new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
333 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
334
335 /*
336 * A new process must start with interrupts disabled, see schedule_tail()
337 * and finish_task_switch(). (If we do not do it and if a timer interrupt
338 * hits before we unlock and attempts to take the rq->lock, we deadlock.)
339 *
340 * Thus, kpsr |= PSR_PIL.
341 */
342 ti->ksp = (unsigned long) new_stack;
343 p->thread.kregs = childregs;
344
345 if (unlikely(p->flags & PF_KTHREAD)) {
346 extern int nwindows;
347 unsigned long psr;
348 memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ);
349 p->thread.flags |= SPARC_FLAG_KTHREAD;
350 p->thread.current_ds = KERNEL_DS;
351 ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8);
352 childregs->u_regs[UREG_G1] = sp; /* function */
353 childregs->u_regs[UREG_G2] = arg;
354 psr = childregs->psr = get_psr();
355 ti->kpsr = psr | PSR_PIL;
356 ti->kwim = 1 << (((psr & PSR_CWP) + 1) % nwindows);
357 return 0;
358 }
359 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
360 childregs->u_regs[UREG_FP] = sp;
361 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
362 p->thread.current_ds = USER_DS;
363 ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
364 ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
365 ti->kwim = current->thread.fork_kwim;
366
367 if (sp != regs->u_regs[UREG_FP]) {
368 struct sparc_stackf __user *childstack;
369 struct sparc_stackf __user *parentstack;
370
371 /*
372 * This is a clone() call with supplied user stack.
373 * Set some valid stack frames to give to the child.
374 */
375 childstack = (struct sparc_stackf __user *)
376 (sp & ~0xfUL);
377 parentstack = (struct sparc_stackf __user *)
378 regs->u_regs[UREG_FP];
379
380#if 0
381 printk("clone: parent stack:\n");
382 show_stackframe(parentstack);
383#endif
384
385 childstack = clone_stackframe(childstack, parentstack);
386 if (!childstack)
387 return -EFAULT;
388
389#if 0
390 printk("clone: child stack:\n");
391 show_stackframe(childstack);
392#endif
393
394 childregs->u_regs[UREG_FP] = (unsigned long)childstack;
395 }
396
397#ifdef CONFIG_SMP
398 /* FPU must be disabled on SMP. */
399 childregs->psr &= ~PSR_EF;
400 clear_tsk_thread_flag(p, TIF_USEDFPU);
401#endif
402
403 /* Set the return value for the child. */
404 childregs->u_regs[UREG_I0] = current->pid;
405 childregs->u_regs[UREG_I1] = 1;
406
407 /* Set the return value for the parent. */
408 regs->u_regs[UREG_I1] = 0;
409
410 if (clone_flags & CLONE_SETTLS)
411 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
412
413 return 0;
414}
415
416/*
417 * fill in the fpu structure for a core dump.
418 */
419int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
420{
421 if (used_math()) {
422 memset(fpregs, 0, sizeof(*fpregs));
423 fpregs->pr_q_entrysize = 8;
424 return 1;
425 }
426#ifdef CONFIG_SMP
427 if (test_thread_flag(TIF_USEDFPU)) {
428 put_psr(get_psr() | PSR_EF);
429 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
430 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
431 if (regs != NULL) {
432 regs->psr &= ~(PSR_EF);
433 clear_thread_flag(TIF_USEDFPU);
434 }
435 }
436#else
437 if (current == last_task_used_math) {
438 put_psr(get_psr() | PSR_EF);
439 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
440 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
441 if (regs != NULL) {
442 regs->psr &= ~(PSR_EF);
443 last_task_used_math = NULL;
444 }
445 }
446#endif
447 memcpy(&fpregs->pr_fr.pr_regs[0],
448 ¤t->thread.float_regs[0],
449 (sizeof(unsigned long) * 32));
450 fpregs->pr_fsr = current->thread.fsr;
451 fpregs->pr_qcnt = current->thread.fpqdepth;
452 fpregs->pr_q_entrysize = 8;
453 fpregs->pr_en = 1;
454 if(fpregs->pr_qcnt != 0) {
455 memcpy(&fpregs->pr_q[0],
456 ¤t->thread.fpqueue[0],
457 sizeof(struct fpq) * fpregs->pr_qcnt);
458 }
459 /* Zero out the rest. */
460 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
461 sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
462 return 1;
463}
464
465unsigned long get_wchan(struct task_struct *task)
466{
467 unsigned long pc, fp, bias = 0;
468 unsigned long task_base = (unsigned long) task;
469 unsigned long ret = 0;
470 struct reg_window32 *rw;
471 int count = 0;
472
473 if (!task || task == current ||
474 task->state == TASK_RUNNING)
475 goto out;
476
477 fp = task_thread_info(task)->ksp + bias;
478 do {
479 /* Bogus frame pointer? */
480 if (fp < (task_base + sizeof(struct thread_info)) ||
481 fp >= (task_base + (2 * PAGE_SIZE)))
482 break;
483 rw = (struct reg_window32 *) fp;
484 pc = rw->ins[7];
485 if (!in_sched_functions(pc)) {
486 ret = pc;
487 goto out;
488 }
489 fp = rw->ins[6] + bias;
490 } while (++count < 16);
491
492out:
493 return ret;
494}
495
1// SPDX-License-Identifier: GPL-2.0
2/* linux/arch/sparc/kernel/process.c
3 *
4 * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
5 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
6 */
7
8/*
9 * This file handles the architecture-dependent parts of process handling..
10 */
11#include <linux/elfcore.h>
12#include <linux/errno.h>
13#include <linux/module.h>
14#include <linux/sched.h>
15#include <linux/sched/debug.h>
16#include <linux/sched/task.h>
17#include <linux/sched/task_stack.h>
18#include <linux/kernel.h>
19#include <linux/mm.h>
20#include <linux/stddef.h>
21#include <linux/ptrace.h>
22#include <linux/user.h>
23#include <linux/smp.h>
24#include <linux/reboot.h>
25#include <linux/delay.h>
26#include <linux/pm.h>
27#include <linux/slab.h>
28#include <linux/cpu.h>
29
30#include <asm/auxio.h>
31#include <asm/oplib.h>
32#include <linux/uaccess.h>
33#include <asm/page.h>
34#include <asm/delay.h>
35#include <asm/processor.h>
36#include <asm/psr.h>
37#include <asm/elf.h>
38#include <asm/prom.h>
39#include <asm/unistd.h>
40#include <asm/setup.h>
41
42#include "kernel.h"
43
44/*
45 * Power management idle function
46 * Set in pm platform drivers (apc.c and pmc.c)
47 */
48void (*sparc_idle)(void);
49
50/*
51 * Power-off handler instantiation for pm.h compliance
52 * This is done via auxio, but could be used as a fallback
53 * handler when auxio is not present-- unused for now...
54 */
55void (*pm_power_off)(void) = machine_power_off;
56EXPORT_SYMBOL(pm_power_off);
57
58/*
59 * sysctl - toggle power-off restriction for serial console
60 * systems in machine_power_off()
61 */
62int scons_pwroff = 1;
63
64extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
65
66struct task_struct *last_task_used_math = NULL;
67struct thread_info *current_set[NR_CPUS];
68
69/* Idle loop support. */
70void arch_cpu_idle(void)
71{
72 if (sparc_idle)
73 (*sparc_idle)();
74}
75
76/* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
77void machine_halt(void)
78{
79 local_irq_enable();
80 mdelay(8);
81 local_irq_disable();
82 prom_halt();
83 panic("Halt failed!");
84}
85
86void machine_restart(char * cmd)
87{
88 char *p;
89
90 local_irq_enable();
91 mdelay(8);
92 local_irq_disable();
93
94 p = strchr (reboot_command, '\n');
95 if (p) *p = 0;
96 if (cmd)
97 prom_reboot(cmd);
98 if (*reboot_command)
99 prom_reboot(reboot_command);
100 prom_feval ("reset");
101 panic("Reboot failed!");
102}
103
104void machine_power_off(void)
105{
106 if (auxio_power_register &&
107 (!of_node_is_type(of_console_device, "serial") || scons_pwroff)) {
108 u8 power_register = sbus_readb(auxio_power_register);
109 power_register |= AUXIO_POWER_OFF;
110 sbus_writeb(power_register, auxio_power_register);
111 }
112
113 machine_halt();
114}
115
116void show_regs(struct pt_regs *r)
117{
118 struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14];
119
120 show_regs_print_info(KERN_DEFAULT);
121
122 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
123 r->psr, r->pc, r->npc, r->y, print_tainted());
124 printk("PC: <%pS>\n", (void *) r->pc);
125 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
126 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
127 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
128 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
129 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
130 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
131 printk("RPC: <%pS>\n", (void *) r->u_regs[15]);
132
133 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
134 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
135 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
136 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
137 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
138 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
139}
140
141/*
142 * The show_stack() is external API which we do not use ourselves.
143 * The oops is printed in die_if_kernel.
144 */
145void show_stack(struct task_struct *tsk, unsigned long *_ksp, const char *loglvl)
146{
147 unsigned long pc, fp;
148 unsigned long task_base;
149 struct reg_window32 *rw;
150 int count = 0;
151
152 if (!tsk)
153 tsk = current;
154
155 if (tsk == current && !_ksp)
156 __asm__ __volatile__("mov %%fp, %0" : "=r" (_ksp));
157
158 task_base = (unsigned long) task_stack_page(tsk);
159 fp = (unsigned long) _ksp;
160 do {
161 /* Bogus frame pointer? */
162 if (fp < (task_base + sizeof(struct thread_info)) ||
163 fp >= (task_base + (PAGE_SIZE << 1)))
164 break;
165 rw = (struct reg_window32 *) fp;
166 pc = rw->ins[7];
167 printk("%s[%08lx : ", loglvl, pc);
168 printk("%s%pS ] ", loglvl, (void *) pc);
169 fp = rw->ins[6];
170 } while (++count < 16);
171 printk("%s\n", loglvl);
172}
173
174/*
175 * Free current thread data structures etc..
176 */
177void exit_thread(struct task_struct *tsk)
178{
179#ifndef CONFIG_SMP
180 if (last_task_used_math == tsk) {
181#else
182 if (test_tsk_thread_flag(tsk, TIF_USEDFPU)) {
183#endif
184 /* Keep process from leaving FPU in a bogon state. */
185 put_psr(get_psr() | PSR_EF);
186 fpsave(&tsk->thread.float_regs[0], &tsk->thread.fsr,
187 &tsk->thread.fpqueue[0], &tsk->thread.fpqdepth);
188#ifndef CONFIG_SMP
189 last_task_used_math = NULL;
190#else
191 clear_ti_thread_flag(task_thread_info(tsk), TIF_USEDFPU);
192#endif
193 }
194}
195
196void flush_thread(void)
197{
198 current_thread_info()->w_saved = 0;
199
200#ifndef CONFIG_SMP
201 if(last_task_used_math == current) {
202#else
203 if (test_thread_flag(TIF_USEDFPU)) {
204#endif
205 /* Clean the fpu. */
206 put_psr(get_psr() | PSR_EF);
207 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
208 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
209#ifndef CONFIG_SMP
210 last_task_used_math = NULL;
211#else
212 clear_thread_flag(TIF_USEDFPU);
213#endif
214 }
215}
216
217static inline struct sparc_stackf __user *
218clone_stackframe(struct sparc_stackf __user *dst,
219 struct sparc_stackf __user *src)
220{
221 unsigned long size, fp;
222 struct sparc_stackf *tmp;
223 struct sparc_stackf __user *sp;
224
225 if (get_user(tmp, &src->fp))
226 return NULL;
227
228 fp = (unsigned long) tmp;
229 size = (fp - ((unsigned long) src));
230 fp = (unsigned long) dst;
231 sp = (struct sparc_stackf __user *)(fp - size);
232
233 /* do_fork() grabs the parent semaphore, we must release it
234 * temporarily so we can build the child clone stack frame
235 * without deadlocking.
236 */
237 if (__copy_user(sp, src, size))
238 sp = NULL;
239 else if (put_user(fp, &sp->fp))
240 sp = NULL;
241
242 return sp;
243}
244
245/* Copy a Sparc thread. The fork() return value conventions
246 * under SunOS are nothing short of bletcherous:
247 * Parent --> %o0 == childs pid, %o1 == 0
248 * Child --> %o0 == parents pid, %o1 == 1
249 *
250 * NOTE: We have a separate fork kpsr/kwim because
251 * the parent could change these values between
252 * sys_fork invocation and when we reach here
253 * if the parent should sleep while trying to
254 * allocate the task_struct and kernel stack in
255 * do_fork().
256 * XXX See comment above sys_vfork in sparc64. todo.
257 */
258extern void ret_from_fork(void);
259extern void ret_from_kernel_thread(void);
260
261int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
262{
263 unsigned long clone_flags = args->flags;
264 unsigned long sp = args->stack;
265 unsigned long tls = args->tls;
266 struct thread_info *ti = task_thread_info(p);
267 struct pt_regs *childregs, *regs = current_pt_regs();
268 char *new_stack;
269
270#ifndef CONFIG_SMP
271 if(last_task_used_math == current) {
272#else
273 if (test_thread_flag(TIF_USEDFPU)) {
274#endif
275 put_psr(get_psr() | PSR_EF);
276 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
277 &p->thread.fpqueue[0], &p->thread.fpqdepth);
278 }
279
280 /*
281 * p->thread_info new_stack childregs stack bottom
282 * ! ! ! !
283 * V V (stk.fr.) V (pt_regs) V
284 * +----- - - - - - ------+===========+=============+
285 */
286 new_stack = task_stack_page(p) + THREAD_SIZE;
287 new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
288 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
289
290 /*
291 * A new process must start with interrupts disabled, see schedule_tail()
292 * and finish_task_switch(). (If we do not do it and if a timer interrupt
293 * hits before we unlock and attempts to take the rq->lock, we deadlock.)
294 *
295 * Thus, kpsr |= PSR_PIL.
296 */
297 ti->ksp = (unsigned long) new_stack;
298 p->thread.kregs = childregs;
299
300 if (unlikely(args->fn)) {
301 extern int nwindows;
302 unsigned long psr;
303 memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ);
304 ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8);
305 childregs->u_regs[UREG_G1] = (unsigned long) args->fn;
306 childregs->u_regs[UREG_G2] = (unsigned long) args->fn_arg;
307 psr = childregs->psr = get_psr();
308 ti->kpsr = psr | PSR_PIL;
309 ti->kwim = 1 << (((psr & PSR_CWP) + 1) % nwindows);
310 return 0;
311 }
312 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
313 childregs->u_regs[UREG_FP] = sp;
314 ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
315 ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
316 ti->kwim = current->thread.fork_kwim;
317
318 if (sp != regs->u_regs[UREG_FP]) {
319 struct sparc_stackf __user *childstack;
320 struct sparc_stackf __user *parentstack;
321
322 /*
323 * This is a clone() call with supplied user stack.
324 * Set some valid stack frames to give to the child.
325 */
326 childstack = (struct sparc_stackf __user *)
327 (sp & ~0xfUL);
328 parentstack = (struct sparc_stackf __user *)
329 regs->u_regs[UREG_FP];
330
331#if 0
332 printk("clone: parent stack:\n");
333 show_stackframe(parentstack);
334#endif
335
336 childstack = clone_stackframe(childstack, parentstack);
337 if (!childstack)
338 return -EFAULT;
339
340#if 0
341 printk("clone: child stack:\n");
342 show_stackframe(childstack);
343#endif
344
345 childregs->u_regs[UREG_FP] = (unsigned long)childstack;
346 }
347
348#ifdef CONFIG_SMP
349 /* FPU must be disabled on SMP. */
350 childregs->psr &= ~PSR_EF;
351 clear_tsk_thread_flag(p, TIF_USEDFPU);
352#endif
353
354 /* Set the return value for the child. */
355 childregs->u_regs[UREG_I0] = current->pid;
356 childregs->u_regs[UREG_I1] = 1;
357
358 /* Set the return value for the parent. */
359 regs->u_regs[UREG_I1] = 0;
360
361 if (clone_flags & CLONE_SETTLS)
362 childregs->u_regs[UREG_G7] = tls;
363
364 return 0;
365}
366
367unsigned long __get_wchan(struct task_struct *task)
368{
369 unsigned long pc, fp, bias = 0;
370 unsigned long task_base = (unsigned long) task;
371 unsigned long ret = 0;
372 struct reg_window32 *rw;
373 int count = 0;
374
375 fp = task_thread_info(task)->ksp + bias;
376 do {
377 /* Bogus frame pointer? */
378 if (fp < (task_base + sizeof(struct thread_info)) ||
379 fp >= (task_base + (2 * PAGE_SIZE)))
380 break;
381 rw = (struct reg_window32 *) fp;
382 pc = rw->ins[7];
383 if (!in_sched_functions(pc)) {
384 ret = pc;
385 goto out;
386 }
387 fp = rw->ins[6] + bias;
388 } while (++count < 16);
389
390out:
391 return ret;
392}
393