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1 /*
2  *  Derived from "arch/i386/kernel/process.c"
3  *    Copyright (C) 1995  Linus Torvalds
4  *
5  *  Updated and modified by Cort Dougan (cort@cs.nmt.edu) and
6  *  Paul Mackerras (paulus@cs.anu.edu.au)
7  *
8  *  PowerPC version
9  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
10  *
11  *  This program is free software; you can redistribute it and/or
12  *  modify it under the terms of the GNU General Public License
13  *  as published by the Free Software Foundation; either version
14  *  2 of the License, or (at your option) any later version.
15  */
16 
17 #include <linux/errno.h>
18 #include <linux/sched.h>
19 #include <linux/kernel.h>
20 #include <linux/mm.h>
21 #include <linux/smp.h>
22 #include <linux/stddef.h>
23 #include <linux/unistd.h>
24 #include <linux/ptrace.h>
25 #include <linux/slab.h>
26 #include <linux/user.h>
27 #include <linux/elf.h>
28 #include <linux/prctl.h>
29 #include <linux/init_task.h>
30 #include <linux/export.h>
31 #include <linux/kallsyms.h>
32 #include <linux/mqueue.h>
33 #include <linux/hardirq.h>
34 #include <linux/utsname.h>
35 #include <linux/ftrace.h>
36 #include <linux/kernel_stat.h>
37 #include <linux/personality.h>
38 #include <linux/random.h>
39 #include <linux/hw_breakpoint.h>
40 
41 #include <asm/pgtable.h>
42 #include <asm/uaccess.h>
43 #include <asm/io.h>
44 #include <asm/processor.h>
45 #include <asm/mmu.h>
46 #include <asm/prom.h>
47 #include <asm/machdep.h>
48 #include <asm/time.h>
49 #include <asm/runlatch.h>
50 #include <asm/syscalls.h>
51 #include <asm/switch_to.h>
52 #include <asm/tm.h>
53 #include <asm/debug.h>
54 #ifdef CONFIG_PPC64
55 #include <asm/firmware.h>
56 #endif
57 #include <asm/code-patching.h>
58 #include <linux/kprobes.h>
59 #include <linux/kdebug.h>
60 
61 /* Transactional Memory debug */
62 #ifdef TM_DEBUG_SW
63 #define TM_DEBUG(x...) printk(KERN_INFO x)
64 #else
65 #define TM_DEBUG(x...) do { } while(0)
66 #endif
67 
68 extern unsigned long _get_SP(void);
69 
70 #ifndef CONFIG_SMP
71 struct task_struct *last_task_used_math = NULL;
72 struct task_struct *last_task_used_altivec = NULL;
73 struct task_struct *last_task_used_vsx = NULL;
74 struct task_struct *last_task_used_spe = NULL;
75 #endif
76 
77 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
giveup_fpu_maybe_transactional(struct task_struct * tsk)78 void giveup_fpu_maybe_transactional(struct task_struct *tsk)
79 {
80 	/*
81 	 * If we are saving the current thread's registers, and the
82 	 * thread is in a transactional state, set the TIF_RESTORE_TM
83 	 * bit so that we know to restore the registers before
84 	 * returning to userspace.
85 	 */
86 	if (tsk == current && tsk->thread.regs &&
87 	    MSR_TM_ACTIVE(tsk->thread.regs->msr) &&
88 	    !test_thread_flag(TIF_RESTORE_TM)) {
89 		tsk->thread.tm_orig_msr = tsk->thread.regs->msr;
90 		set_thread_flag(TIF_RESTORE_TM);
91 	}
92 
93 	giveup_fpu(tsk);
94 }
95 
giveup_altivec_maybe_transactional(struct task_struct * tsk)96 void giveup_altivec_maybe_transactional(struct task_struct *tsk)
97 {
98 	/*
99 	 * If we are saving the current thread's registers, and the
100 	 * thread is in a transactional state, set the TIF_RESTORE_TM
101 	 * bit so that we know to restore the registers before
102 	 * returning to userspace.
103 	 */
104 	if (tsk == current && tsk->thread.regs &&
105 	    MSR_TM_ACTIVE(tsk->thread.regs->msr) &&
106 	    !test_thread_flag(TIF_RESTORE_TM)) {
107 		tsk->thread.tm_orig_msr = tsk->thread.regs->msr;
108 		set_thread_flag(TIF_RESTORE_TM);
109 	}
110 
111 	giveup_altivec(tsk);
112 }
113 
114 #else
115 #define giveup_fpu_maybe_transactional(tsk)	giveup_fpu(tsk)
116 #define giveup_altivec_maybe_transactional(tsk)	giveup_altivec(tsk)
117 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
118 
119 #ifdef CONFIG_PPC_FPU
120 /*
121  * Make sure the floating-point register state in the
122  * the thread_struct is up to date for task tsk.
123  */
flush_fp_to_thread(struct task_struct * tsk)124 void flush_fp_to_thread(struct task_struct *tsk)
125 {
126 	if (tsk->thread.regs) {
127 		/*
128 		 * We need to disable preemption here because if we didn't,
129 		 * another process could get scheduled after the regs->msr
130 		 * test but before we have finished saving the FP registers
131 		 * to the thread_struct.  That process could take over the
132 		 * FPU, and then when we get scheduled again we would store
133 		 * bogus values for the remaining FP registers.
134 		 */
135 		preempt_disable();
136 		if (tsk->thread.regs->msr & MSR_FP) {
137 #ifdef CONFIG_SMP
138 			/*
139 			 * This should only ever be called for current or
140 			 * for a stopped child process.  Since we save away
141 			 * the FP register state on context switch on SMP,
142 			 * there is something wrong if a stopped child appears
143 			 * to still have its FP state in the CPU registers.
144 			 */
145 			BUG_ON(tsk != current);
146 #endif
147 			giveup_fpu_maybe_transactional(tsk);
148 		}
149 		preempt_enable();
150 	}
151 }
152 EXPORT_SYMBOL_GPL(flush_fp_to_thread);
153 #endif /* CONFIG_PPC_FPU */
154 
enable_kernel_fp(void)155 void enable_kernel_fp(void)
156 {
157 	WARN_ON(preemptible());
158 
159 #ifdef CONFIG_SMP
160 	if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
161 		giveup_fpu_maybe_transactional(current);
162 	else
163 		giveup_fpu(NULL);	/* just enables FP for kernel */
164 #else
165 	giveup_fpu_maybe_transactional(last_task_used_math);
166 #endif /* CONFIG_SMP */
167 }
168 EXPORT_SYMBOL(enable_kernel_fp);
169 
170 #ifdef CONFIG_ALTIVEC
enable_kernel_altivec(void)171 void enable_kernel_altivec(void)
172 {
173 	WARN_ON(preemptible());
174 
175 #ifdef CONFIG_SMP
176 	if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
177 		giveup_altivec_maybe_transactional(current);
178 	else
179 		giveup_altivec_notask();
180 #else
181 	giveup_altivec_maybe_transactional(last_task_used_altivec);
182 #endif /* CONFIG_SMP */
183 }
184 EXPORT_SYMBOL(enable_kernel_altivec);
185 
186 /*
187  * Make sure the VMX/Altivec register state in the
188  * the thread_struct is up to date for task tsk.
189  */
flush_altivec_to_thread(struct task_struct * tsk)190 void flush_altivec_to_thread(struct task_struct *tsk)
191 {
192 	if (tsk->thread.regs) {
193 		preempt_disable();
194 		if (tsk->thread.regs->msr & MSR_VEC) {
195 #ifdef CONFIG_SMP
196 			BUG_ON(tsk != current);
197 #endif
198 			giveup_altivec_maybe_transactional(tsk);
199 		}
200 		preempt_enable();
201 	}
202 }
203 EXPORT_SYMBOL_GPL(flush_altivec_to_thread);
204 #endif /* CONFIG_ALTIVEC */
205 
206 #ifdef CONFIG_VSX
207 #if 0
208 /* not currently used, but some crazy RAID module might want to later */
209 void enable_kernel_vsx(void)
210 {
211 	WARN_ON(preemptible());
212 
213 #ifdef CONFIG_SMP
214 	if (current->thread.regs && (current->thread.regs->msr & MSR_VSX))
215 		giveup_vsx(current);
216 	else
217 		giveup_vsx(NULL);	/* just enable vsx for kernel - force */
218 #else
219 	giveup_vsx(last_task_used_vsx);
220 #endif /* CONFIG_SMP */
221 }
222 EXPORT_SYMBOL(enable_kernel_vsx);
223 #endif
224 
giveup_vsx(struct task_struct * tsk)225 void giveup_vsx(struct task_struct *tsk)
226 {
227 	giveup_fpu_maybe_transactional(tsk);
228 	giveup_altivec_maybe_transactional(tsk);
229 	__giveup_vsx(tsk);
230 }
231 EXPORT_SYMBOL(giveup_vsx);
232 
flush_vsx_to_thread(struct task_struct * tsk)233 void flush_vsx_to_thread(struct task_struct *tsk)
234 {
235 	if (tsk->thread.regs) {
236 		preempt_disable();
237 		if (tsk->thread.regs->msr & MSR_VSX) {
238 #ifdef CONFIG_SMP
239 			BUG_ON(tsk != current);
240 #endif
241 			giveup_vsx(tsk);
242 		}
243 		preempt_enable();
244 	}
245 }
246 EXPORT_SYMBOL_GPL(flush_vsx_to_thread);
247 #endif /* CONFIG_VSX */
248 
249 #ifdef CONFIG_SPE
250 
enable_kernel_spe(void)251 void enable_kernel_spe(void)
252 {
253 	WARN_ON(preemptible());
254 
255 #ifdef CONFIG_SMP
256 	if (current->thread.regs && (current->thread.regs->msr & MSR_SPE))
257 		giveup_spe(current);
258 	else
259 		giveup_spe(NULL);	/* just enable SPE for kernel - force */
260 #else
261 	giveup_spe(last_task_used_spe);
262 #endif /* __SMP __ */
263 }
264 EXPORT_SYMBOL(enable_kernel_spe);
265 
flush_spe_to_thread(struct task_struct * tsk)266 void flush_spe_to_thread(struct task_struct *tsk)
267 {
268 	if (tsk->thread.regs) {
269 		preempt_disable();
270 		if (tsk->thread.regs->msr & MSR_SPE) {
271 #ifdef CONFIG_SMP
272 			BUG_ON(tsk != current);
273 #endif
274 			tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
275 			giveup_spe(tsk);
276 		}
277 		preempt_enable();
278 	}
279 }
280 #endif /* CONFIG_SPE */
281 
282 #ifndef CONFIG_SMP
283 /*
284  * If we are doing lazy switching of CPU state (FP, altivec or SPE),
285  * and the current task has some state, discard it.
286  */
discard_lazy_cpu_state(void)287 void discard_lazy_cpu_state(void)
288 {
289 	preempt_disable();
290 	if (last_task_used_math == current)
291 		last_task_used_math = NULL;
292 #ifdef CONFIG_ALTIVEC
293 	if (last_task_used_altivec == current)
294 		last_task_used_altivec = NULL;
295 #endif /* CONFIG_ALTIVEC */
296 #ifdef CONFIG_VSX
297 	if (last_task_used_vsx == current)
298 		last_task_used_vsx = NULL;
299 #endif /* CONFIG_VSX */
300 #ifdef CONFIG_SPE
301 	if (last_task_used_spe == current)
302 		last_task_used_spe = NULL;
303 #endif
304 	preempt_enable();
305 }
306 #endif /* CONFIG_SMP */
307 
308 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
do_send_trap(struct pt_regs * regs,unsigned long address,unsigned long error_code,int signal_code,int breakpt)309 void do_send_trap(struct pt_regs *regs, unsigned long address,
310 		  unsigned long error_code, int signal_code, int breakpt)
311 {
312 	siginfo_t info;
313 
314 	current->thread.trap_nr = signal_code;
315 	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
316 			11, SIGSEGV) == NOTIFY_STOP)
317 		return;
318 
319 	/* Deliver the signal to userspace */
320 	info.si_signo = SIGTRAP;
321 	info.si_errno = breakpt;	/* breakpoint or watchpoint id */
322 	info.si_code = signal_code;
323 	info.si_addr = (void __user *)address;
324 	force_sig_info(SIGTRAP, &info, current);
325 }
326 #else	/* !CONFIG_PPC_ADV_DEBUG_REGS */
do_break(struct pt_regs * regs,unsigned long address,unsigned long error_code)327 void do_break (struct pt_regs *regs, unsigned long address,
328 		    unsigned long error_code)
329 {
330 	siginfo_t info;
331 
332 	current->thread.trap_nr = TRAP_HWBKPT;
333 	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
334 			11, SIGSEGV) == NOTIFY_STOP)
335 		return;
336 
337 	if (debugger_break_match(regs))
338 		return;
339 
340 	/* Clear the breakpoint */
341 	hw_breakpoint_disable();
342 
343 	/* Deliver the signal to userspace */
344 	info.si_signo = SIGTRAP;
345 	info.si_errno = 0;
346 	info.si_code = TRAP_HWBKPT;
347 	info.si_addr = (void __user *)address;
348 	force_sig_info(SIGTRAP, &info, current);
349 }
350 #endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
351 
352 static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk);
353 
354 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
355 /*
356  * Set the debug registers back to their default "safe" values.
357  */
set_debug_reg_defaults(struct thread_struct * thread)358 static void set_debug_reg_defaults(struct thread_struct *thread)
359 {
360 	thread->debug.iac1 = thread->debug.iac2 = 0;
361 #if CONFIG_PPC_ADV_DEBUG_IACS > 2
362 	thread->debug.iac3 = thread->debug.iac4 = 0;
363 #endif
364 	thread->debug.dac1 = thread->debug.dac2 = 0;
365 #if CONFIG_PPC_ADV_DEBUG_DVCS > 0
366 	thread->debug.dvc1 = thread->debug.dvc2 = 0;
367 #endif
368 	thread->debug.dbcr0 = 0;
369 #ifdef CONFIG_BOOKE
370 	/*
371 	 * Force User/Supervisor bits to b11 (user-only MSR[PR]=1)
372 	 */
373 	thread->debug.dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US |
374 			DBCR1_IAC3US | DBCR1_IAC4US;
375 	/*
376 	 * Force Data Address Compare User/Supervisor bits to be User-only
377 	 * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0.
378 	 */
379 	thread->debug.dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US;
380 #else
381 	thread->debug.dbcr1 = 0;
382 #endif
383 }
384 
prime_debug_regs(struct debug_reg * debug)385 static void prime_debug_regs(struct debug_reg *debug)
386 {
387 	/*
388 	 * We could have inherited MSR_DE from userspace, since
389 	 * it doesn't get cleared on exception entry.  Make sure
390 	 * MSR_DE is clear before we enable any debug events.
391 	 */
392 	mtmsr(mfmsr() & ~MSR_DE);
393 
394 	mtspr(SPRN_IAC1, debug->iac1);
395 	mtspr(SPRN_IAC2, debug->iac2);
396 #if CONFIG_PPC_ADV_DEBUG_IACS > 2
397 	mtspr(SPRN_IAC3, debug->iac3);
398 	mtspr(SPRN_IAC4, debug->iac4);
399 #endif
400 	mtspr(SPRN_DAC1, debug->dac1);
401 	mtspr(SPRN_DAC2, debug->dac2);
402 #if CONFIG_PPC_ADV_DEBUG_DVCS > 0
403 	mtspr(SPRN_DVC1, debug->dvc1);
404 	mtspr(SPRN_DVC2, debug->dvc2);
405 #endif
406 	mtspr(SPRN_DBCR0, debug->dbcr0);
407 	mtspr(SPRN_DBCR1, debug->dbcr1);
408 #ifdef CONFIG_BOOKE
409 	mtspr(SPRN_DBCR2, debug->dbcr2);
410 #endif
411 }
412 /*
413  * Unless neither the old or new thread are making use of the
414  * debug registers, set the debug registers from the values
415  * stored in the new thread.
416  */
switch_booke_debug_regs(struct debug_reg * new_debug)417 void switch_booke_debug_regs(struct debug_reg *new_debug)
418 {
419 	if ((current->thread.debug.dbcr0 & DBCR0_IDM)
420 		|| (new_debug->dbcr0 & DBCR0_IDM))
421 			prime_debug_regs(new_debug);
422 }
423 EXPORT_SYMBOL_GPL(switch_booke_debug_regs);
424 #else	/* !CONFIG_PPC_ADV_DEBUG_REGS */
425 #ifndef CONFIG_HAVE_HW_BREAKPOINT
set_debug_reg_defaults(struct thread_struct * thread)426 static void set_debug_reg_defaults(struct thread_struct *thread)
427 {
428 	thread->hw_brk.address = 0;
429 	thread->hw_brk.type = 0;
430 	set_breakpoint(&thread->hw_brk);
431 }
432 #endif /* !CONFIG_HAVE_HW_BREAKPOINT */
433 #endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
434 
435 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
__set_dabr(unsigned long dabr,unsigned long dabrx)436 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
437 {
438 	mtspr(SPRN_DAC1, dabr);
439 #ifdef CONFIG_PPC_47x
440 	isync();
441 #endif
442 	return 0;
443 }
444 #elif defined(CONFIG_PPC_BOOK3S)
__set_dabr(unsigned long dabr,unsigned long dabrx)445 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
446 {
447 	mtspr(SPRN_DABR, dabr);
448 	if (cpu_has_feature(CPU_FTR_DABRX))
449 		mtspr(SPRN_DABRX, dabrx);
450 	return 0;
451 }
452 #else
__set_dabr(unsigned long dabr,unsigned long dabrx)453 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
454 {
455 	return -EINVAL;
456 }
457 #endif
458 
set_dabr(struct arch_hw_breakpoint * brk)459 static inline int set_dabr(struct arch_hw_breakpoint *brk)
460 {
461 	unsigned long dabr, dabrx;
462 
463 	dabr = brk->address | (brk->type & HW_BRK_TYPE_DABR);
464 	dabrx = ((brk->type >> 3) & 0x7);
465 
466 	if (ppc_md.set_dabr)
467 		return ppc_md.set_dabr(dabr, dabrx);
468 
469 	return __set_dabr(dabr, dabrx);
470 }
471 
set_dawr(struct arch_hw_breakpoint * brk)472 static inline int set_dawr(struct arch_hw_breakpoint *brk)
473 {
474 	unsigned long dawr, dawrx, mrd;
475 
476 	dawr = brk->address;
477 
478 	dawrx  = (brk->type & (HW_BRK_TYPE_READ | HW_BRK_TYPE_WRITE)) \
479 		                   << (63 - 58); //* read/write bits */
480 	dawrx |= ((brk->type & (HW_BRK_TYPE_TRANSLATE)) >> 2) \
481 		                   << (63 - 59); //* translate */
482 	dawrx |= (brk->type & (HW_BRK_TYPE_PRIV_ALL)) \
483 		                   >> 3; //* PRIM bits */
484 	/* dawr length is stored in field MDR bits 48:53.  Matches range in
485 	   doublewords (64 bits) baised by -1 eg. 0b000000=1DW and
486 	   0b111111=64DW.
487 	   brk->len is in bytes.
488 	   This aligns up to double word size, shifts and does the bias.
489 	*/
490 	mrd = ((brk->len + 7) >> 3) - 1;
491 	dawrx |= (mrd & 0x3f) << (63 - 53);
492 
493 	if (ppc_md.set_dawr)
494 		return ppc_md.set_dawr(dawr, dawrx);
495 	mtspr(SPRN_DAWR, dawr);
496 	mtspr(SPRN_DAWRX, dawrx);
497 	return 0;
498 }
499 
__set_breakpoint(struct arch_hw_breakpoint * brk)500 void __set_breakpoint(struct arch_hw_breakpoint *brk)
501 {
502 	__get_cpu_var(current_brk) = *brk;
503 
504 	if (cpu_has_feature(CPU_FTR_DAWR))
505 		set_dawr(brk);
506 	else
507 		set_dabr(brk);
508 }
509 
set_breakpoint(struct arch_hw_breakpoint * brk)510 void set_breakpoint(struct arch_hw_breakpoint *brk)
511 {
512 	preempt_disable();
513 	__set_breakpoint(brk);
514 	preempt_enable();
515 }
516 
517 #ifdef CONFIG_PPC64
518 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
519 #endif
520 
hw_brk_match(struct arch_hw_breakpoint * a,struct arch_hw_breakpoint * b)521 static inline bool hw_brk_match(struct arch_hw_breakpoint *a,
522 			      struct arch_hw_breakpoint *b)
523 {
524 	if (a->address != b->address)
525 		return false;
526 	if (a->type != b->type)
527 		return false;
528 	if (a->len != b->len)
529 		return false;
530 	return true;
531 }
532 
533 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
tm_reclaim_thread(struct thread_struct * thr,struct thread_info * ti,uint8_t cause)534 static void tm_reclaim_thread(struct thread_struct *thr,
535 			      struct thread_info *ti, uint8_t cause)
536 {
537 	unsigned long msr_diff = 0;
538 
539 	/*
540 	 * If FP/VSX registers have been already saved to the
541 	 * thread_struct, move them to the transact_fp array.
542 	 * We clear the TIF_RESTORE_TM bit since after the reclaim
543 	 * the thread will no longer be transactional.
544 	 */
545 	if (test_ti_thread_flag(ti, TIF_RESTORE_TM)) {
546 		msr_diff = thr->tm_orig_msr & ~thr->regs->msr;
547 		if (msr_diff & MSR_FP)
548 			memcpy(&thr->transact_fp, &thr->fp_state,
549 			       sizeof(struct thread_fp_state));
550 		if (msr_diff & MSR_VEC)
551 			memcpy(&thr->transact_vr, &thr->vr_state,
552 			       sizeof(struct thread_vr_state));
553 		clear_ti_thread_flag(ti, TIF_RESTORE_TM);
554 		msr_diff &= MSR_FP | MSR_VEC | MSR_VSX | MSR_FE0 | MSR_FE1;
555 	}
556 
557 	tm_reclaim(thr, thr->regs->msr, cause);
558 
559 	/* Having done the reclaim, we now have the checkpointed
560 	 * FP/VSX values in the registers.  These might be valid
561 	 * even if we have previously called enable_kernel_fp() or
562 	 * flush_fp_to_thread(), so update thr->regs->msr to
563 	 * indicate their current validity.
564 	 */
565 	thr->regs->msr |= msr_diff;
566 }
567 
tm_reclaim_current(uint8_t cause)568 void tm_reclaim_current(uint8_t cause)
569 {
570 	tm_enable();
571 	tm_reclaim_thread(&current->thread, current_thread_info(), cause);
572 }
573 
tm_reclaim_task(struct task_struct * tsk)574 static inline void tm_reclaim_task(struct task_struct *tsk)
575 {
576 	/* We have to work out if we're switching from/to a task that's in the
577 	 * middle of a transaction.
578 	 *
579 	 * In switching we need to maintain a 2nd register state as
580 	 * oldtask->thread.ckpt_regs.  We tm_reclaim(oldproc); this saves the
581 	 * checkpointed (tbegin) state in ckpt_regs and saves the transactional
582 	 * (current) FPRs into oldtask->thread.transact_fpr[].
583 	 *
584 	 * We also context switch (save) TFHAR/TEXASR/TFIAR in here.
585 	 */
586 	struct thread_struct *thr = &tsk->thread;
587 
588 	if (!thr->regs)
589 		return;
590 
591 	if (!MSR_TM_ACTIVE(thr->regs->msr))
592 		goto out_and_saveregs;
593 
594 	/* Stash the original thread MSR, as giveup_fpu et al will
595 	 * modify it.  We hold onto it to see whether the task used
596 	 * FP & vector regs.  If the TIF_RESTORE_TM flag is set,
597 	 * tm_orig_msr is already set.
598 	 */
599 	if (!test_ti_thread_flag(task_thread_info(tsk), TIF_RESTORE_TM))
600 		thr->tm_orig_msr = thr->regs->msr;
601 
602 	TM_DEBUG("--- tm_reclaim on pid %d (NIP=%lx, "
603 		 "ccr=%lx, msr=%lx, trap=%lx)\n",
604 		 tsk->pid, thr->regs->nip,
605 		 thr->regs->ccr, thr->regs->msr,
606 		 thr->regs->trap);
607 
608 	tm_reclaim_thread(thr, task_thread_info(tsk), TM_CAUSE_RESCHED);
609 
610 	TM_DEBUG("--- tm_reclaim on pid %d complete\n",
611 		 tsk->pid);
612 
613 out_and_saveregs:
614 	/* Always save the regs here, even if a transaction's not active.
615 	 * This context-switches a thread's TM info SPRs.  We do it here to
616 	 * be consistent with the restore path (in recheckpoint) which
617 	 * cannot happen later in _switch().
618 	 */
619 	tm_save_sprs(thr);
620 }
621 
622 extern void __tm_recheckpoint(struct thread_struct *thread,
623 			      unsigned long orig_msr);
624 
tm_recheckpoint(struct thread_struct * thread,unsigned long orig_msr)625 void tm_recheckpoint(struct thread_struct *thread,
626 		     unsigned long orig_msr)
627 {
628 	unsigned long flags;
629 
630 	/* We really can't be interrupted here as the TEXASR registers can't
631 	 * change and later in the trecheckpoint code, we have a userspace R1.
632 	 * So let's hard disable over this region.
633 	 */
634 	local_irq_save(flags);
635 	hard_irq_disable();
636 
637 	/* The TM SPRs are restored here, so that TEXASR.FS can be set
638 	 * before the trecheckpoint and no explosion occurs.
639 	 */
640 	tm_restore_sprs(thread);
641 
642 	__tm_recheckpoint(thread, orig_msr);
643 
644 	local_irq_restore(flags);
645 }
646 
tm_recheckpoint_new_task(struct task_struct * new)647 static inline void tm_recheckpoint_new_task(struct task_struct *new)
648 {
649 	unsigned long msr;
650 
651 	if (!cpu_has_feature(CPU_FTR_TM))
652 		return;
653 
654 	/* Recheckpoint the registers of the thread we're about to switch to.
655 	 *
656 	 * If the task was using FP, we non-lazily reload both the original and
657 	 * the speculative FP register states.  This is because the kernel
658 	 * doesn't see if/when a TM rollback occurs, so if we take an FP
659 	 * unavoidable later, we are unable to determine which set of FP regs
660 	 * need to be restored.
661 	 */
662 	if (!new->thread.regs)
663 		return;
664 
665 	if (!MSR_TM_ACTIVE(new->thread.regs->msr)){
666 		tm_restore_sprs(&new->thread);
667 		return;
668 	}
669 	msr = new->thread.tm_orig_msr;
670 	/* Recheckpoint to restore original checkpointed register state. */
671 	TM_DEBUG("*** tm_recheckpoint of pid %d "
672 		 "(new->msr 0x%lx, new->origmsr 0x%lx)\n",
673 		 new->pid, new->thread.regs->msr, msr);
674 
675 	/* This loads the checkpointed FP/VEC state, if used */
676 	tm_recheckpoint(&new->thread, msr);
677 
678 	/* This loads the speculative FP/VEC state, if used */
679 	if (msr & MSR_FP) {
680 		do_load_up_transact_fpu(&new->thread);
681 		new->thread.regs->msr |=
682 			(MSR_FP | new->thread.fpexc_mode);
683 	}
684 #ifdef CONFIG_ALTIVEC
685 	if (msr & MSR_VEC) {
686 		do_load_up_transact_altivec(&new->thread);
687 		new->thread.regs->msr |= MSR_VEC;
688 	}
689 #endif
690 	/* We may as well turn on VSX too since all the state is restored now */
691 	if (msr & MSR_VSX)
692 		new->thread.regs->msr |= MSR_VSX;
693 
694 	TM_DEBUG("*** tm_recheckpoint of pid %d complete "
695 		 "(kernel msr 0x%lx)\n",
696 		 new->pid, mfmsr());
697 }
698 
__switch_to_tm(struct task_struct * prev)699 static inline void __switch_to_tm(struct task_struct *prev)
700 {
701 	if (cpu_has_feature(CPU_FTR_TM)) {
702 		tm_enable();
703 		tm_reclaim_task(prev);
704 	}
705 }
706 
707 /*
708  * This is called if we are on the way out to userspace and the
709  * TIF_RESTORE_TM flag is set.  It checks if we need to reload
710  * FP and/or vector state and does so if necessary.
711  * If userspace is inside a transaction (whether active or
712  * suspended) and FP/VMX/VSX instructions have ever been enabled
713  * inside that transaction, then we have to keep them enabled
714  * and keep the FP/VMX/VSX state loaded while ever the transaction
715  * continues.  The reason is that if we didn't, and subsequently
716  * got a FP/VMX/VSX unavailable interrupt inside a transaction,
717  * we don't know whether it's the same transaction, and thus we
718  * don't know which of the checkpointed state and the transactional
719  * state to use.
720  */
restore_tm_state(struct pt_regs * regs)721 void restore_tm_state(struct pt_regs *regs)
722 {
723 	unsigned long msr_diff;
724 
725 	clear_thread_flag(TIF_RESTORE_TM);
726 	if (!MSR_TM_ACTIVE(regs->msr))
727 		return;
728 
729 	msr_diff = current->thread.tm_orig_msr & ~regs->msr;
730 	msr_diff &= MSR_FP | MSR_VEC | MSR_VSX;
731 	if (msr_diff & MSR_FP) {
732 		fp_enable();
733 		load_fp_state(&current->thread.fp_state);
734 		regs->msr |= current->thread.fpexc_mode;
735 	}
736 	if (msr_diff & MSR_VEC) {
737 		vec_enable();
738 		load_vr_state(&current->thread.vr_state);
739 	}
740 	regs->msr |= msr_diff;
741 }
742 
743 #else
744 #define tm_recheckpoint_new_task(new)
745 #define __switch_to_tm(prev)
746 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
747 
__switch_to(struct task_struct * prev,struct task_struct * new)748 struct task_struct *__switch_to(struct task_struct *prev,
749 	struct task_struct *new)
750 {
751 	struct thread_struct *new_thread, *old_thread;
752 	struct task_struct *last;
753 #ifdef CONFIG_PPC_BOOK3S_64
754 	struct ppc64_tlb_batch *batch;
755 #endif
756 
757 	WARN_ON(!irqs_disabled());
758 
759 	/* Back up the TAR and DSCR across context switches.
760 	 * Note that the TAR is not available for use in the kernel.  (To
761 	 * provide this, the TAR should be backed up/restored on exception
762 	 * entry/exit instead, and be in pt_regs.  FIXME, this should be in
763 	 * pt_regs anyway (for debug).)
764 	 * Save the TAR and DSCR here before we do treclaim/trecheckpoint as
765 	 * these will change them.
766 	 */
767 	save_early_sprs(&prev->thread);
768 
769 	__switch_to_tm(prev);
770 
771 #ifdef CONFIG_SMP
772 	/* avoid complexity of lazy save/restore of fpu
773 	 * by just saving it every time we switch out if
774 	 * this task used the fpu during the last quantum.
775 	 *
776 	 * If it tries to use the fpu again, it'll trap and
777 	 * reload its fp regs.  So we don't have to do a restore
778 	 * every switch, just a save.
779 	 *  -- Cort
780 	 */
781 	if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP))
782 		giveup_fpu(prev);
783 #ifdef CONFIG_ALTIVEC
784 	/*
785 	 * If the previous thread used altivec in the last quantum
786 	 * (thus changing altivec regs) then save them.
787 	 * We used to check the VRSAVE register but not all apps
788 	 * set it, so we don't rely on it now (and in fact we need
789 	 * to save & restore VSCR even if VRSAVE == 0).  -- paulus
790 	 *
791 	 * On SMP we always save/restore altivec regs just to avoid the
792 	 * complexity of changing processors.
793 	 *  -- Cort
794 	 */
795 	if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC))
796 		giveup_altivec(prev);
797 #endif /* CONFIG_ALTIVEC */
798 #ifdef CONFIG_VSX
799 	if (prev->thread.regs && (prev->thread.regs->msr & MSR_VSX))
800 		/* VMX and FPU registers are already save here */
801 		__giveup_vsx(prev);
802 #endif /* CONFIG_VSX */
803 #ifdef CONFIG_SPE
804 	/*
805 	 * If the previous thread used spe in the last quantum
806 	 * (thus changing spe regs) then save them.
807 	 *
808 	 * On SMP we always save/restore spe regs just to avoid the
809 	 * complexity of changing processors.
810 	 */
811 	if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE)))
812 		giveup_spe(prev);
813 #endif /* CONFIG_SPE */
814 
815 #else  /* CONFIG_SMP */
816 #ifdef CONFIG_ALTIVEC
817 	/* Avoid the trap.  On smp this this never happens since
818 	 * we don't set last_task_used_altivec -- Cort
819 	 */
820 	if (new->thread.regs && last_task_used_altivec == new)
821 		new->thread.regs->msr |= MSR_VEC;
822 #endif /* CONFIG_ALTIVEC */
823 #ifdef CONFIG_VSX
824 	if (new->thread.regs && last_task_used_vsx == new)
825 		new->thread.regs->msr |= MSR_VSX;
826 #endif /* CONFIG_VSX */
827 #ifdef CONFIG_SPE
828 	/* Avoid the trap.  On smp this this never happens since
829 	 * we don't set last_task_used_spe
830 	 */
831 	if (new->thread.regs && last_task_used_spe == new)
832 		new->thread.regs->msr |= MSR_SPE;
833 #endif /* CONFIG_SPE */
834 
835 #endif /* CONFIG_SMP */
836 
837 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
838 	switch_booke_debug_regs(&new->thread.debug);
839 #else
840 /*
841  * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would
842  * schedule DABR
843  */
844 #ifndef CONFIG_HAVE_HW_BREAKPOINT
845 	if (unlikely(!hw_brk_match(&__get_cpu_var(current_brk), &new->thread.hw_brk)))
846 		__set_breakpoint(&new->thread.hw_brk);
847 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
848 #endif
849 
850 
851 	new_thread = &new->thread;
852 	old_thread = &current->thread;
853 
854 #ifdef CONFIG_PPC64
855 	/*
856 	 * Collect processor utilization data per process
857 	 */
858 	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
859 		struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
860 		long unsigned start_tb, current_tb;
861 		start_tb = old_thread->start_tb;
862 		cu->current_tb = current_tb = mfspr(SPRN_PURR);
863 		old_thread->accum_tb += (current_tb - start_tb);
864 		new_thread->start_tb = current_tb;
865 	}
866 #endif /* CONFIG_PPC64 */
867 
868 #ifdef CONFIG_PPC_BOOK3S_64
869 	batch = &__get_cpu_var(ppc64_tlb_batch);
870 	if (batch->active) {
871 		current_thread_info()->local_flags |= _TLF_LAZY_MMU;
872 		if (batch->index)
873 			__flush_tlb_pending(batch);
874 		batch->active = 0;
875 	}
876 #endif /* CONFIG_PPC_BOOK3S_64 */
877 
878 	/*
879 	 * We can't take a PMU exception inside _switch() since there is a
880 	 * window where the kernel stack SLB and the kernel stack are out
881 	 * of sync. Hard disable here.
882 	 */
883 	hard_irq_disable();
884 
885 	tm_recheckpoint_new_task(new);
886 
887 	last = _switch(old_thread, new_thread);
888 
889 #ifdef CONFIG_PPC_BOOK3S_64
890 	if (current_thread_info()->local_flags & _TLF_LAZY_MMU) {
891 		current_thread_info()->local_flags &= ~_TLF_LAZY_MMU;
892 		batch = &__get_cpu_var(ppc64_tlb_batch);
893 		batch->active = 1;
894 	}
895 #endif /* CONFIG_PPC_BOOK3S_64 */
896 
897 	return last;
898 }
899 
900 static int instructions_to_print = 16;
901 
show_instructions(struct pt_regs * regs)902 static void show_instructions(struct pt_regs *regs)
903 {
904 	int i;
905 	unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
906 			sizeof(int));
907 
908 	printk("Instruction dump:");
909 
910 	for (i = 0; i < instructions_to_print; i++) {
911 		int instr;
912 
913 		if (!(i % 8))
914 			printk("\n");
915 
916 #if !defined(CONFIG_BOOKE)
917 		/* If executing with the IMMU off, adjust pc rather
918 		 * than print XXXXXXXX.
919 		 */
920 		if (!(regs->msr & MSR_IR))
921 			pc = (unsigned long)phys_to_virt(pc);
922 #endif
923 
924 		/* We use __get_user here *only* to avoid an OOPS on a
925 		 * bad address because the pc *should* only be a
926 		 * kernel address.
927 		 */
928 		if (!__kernel_text_address(pc) ||
929 		     __get_user(instr, (unsigned int __user *)pc)) {
930 			printk(KERN_CONT "XXXXXXXX ");
931 		} else {
932 			if (regs->nip == pc)
933 				printk(KERN_CONT "<%08x> ", instr);
934 			else
935 				printk(KERN_CONT "%08x ", instr);
936 		}
937 
938 		pc += sizeof(int);
939 	}
940 
941 	printk("\n");
942 }
943 
944 static struct regbit {
945 	unsigned long bit;
946 	const char *name;
947 } msr_bits[] = {
948 #if defined(CONFIG_PPC64) && !defined(CONFIG_BOOKE)
949 	{MSR_SF,	"SF"},
950 	{MSR_HV,	"HV"},
951 #endif
952 	{MSR_VEC,	"VEC"},
953 	{MSR_VSX,	"VSX"},
954 #ifdef CONFIG_BOOKE
955 	{MSR_CE,	"CE"},
956 #endif
957 	{MSR_EE,	"EE"},
958 	{MSR_PR,	"PR"},
959 	{MSR_FP,	"FP"},
960 	{MSR_ME,	"ME"},
961 #ifdef CONFIG_BOOKE
962 	{MSR_DE,	"DE"},
963 #else
964 	{MSR_SE,	"SE"},
965 	{MSR_BE,	"BE"},
966 #endif
967 	{MSR_IR,	"IR"},
968 	{MSR_DR,	"DR"},
969 	{MSR_PMM,	"PMM"},
970 #ifndef CONFIG_BOOKE
971 	{MSR_RI,	"RI"},
972 	{MSR_LE,	"LE"},
973 #endif
974 	{0,		NULL}
975 };
976 
printbits(unsigned long val,struct regbit * bits)977 static void printbits(unsigned long val, struct regbit *bits)
978 {
979 	const char *sep = "";
980 
981 	printk("<");
982 	for (; bits->bit; ++bits)
983 		if (val & bits->bit) {
984 			printk("%s%s", sep, bits->name);
985 			sep = ",";
986 		}
987 	printk(">");
988 }
989 
990 #ifdef CONFIG_PPC64
991 #define REG		"%016lx"
992 #define REGS_PER_LINE	4
993 #define LAST_VOLATILE	13
994 #else
995 #define REG		"%08lx"
996 #define REGS_PER_LINE	8
997 #define LAST_VOLATILE	12
998 #endif
999 
show_regs(struct pt_regs * regs)1000 void show_regs(struct pt_regs * regs)
1001 {
1002 	int i, trap;
1003 
1004 	show_regs_print_info(KERN_DEFAULT);
1005 
1006 	printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
1007 	       regs->nip, regs->link, regs->ctr);
1008 	printk("REGS: %p TRAP: %04lx   %s  (%s)\n",
1009 	       regs, regs->trap, print_tainted(), init_utsname()->release);
1010 	printk("MSR: "REG" ", regs->msr);
1011 	printbits(regs->msr, msr_bits);
1012 	printk("  CR: %08lx  XER: %08lx\n", regs->ccr, regs->xer);
1013 	trap = TRAP(regs);
1014 	if ((regs->trap != 0xc00) && cpu_has_feature(CPU_FTR_CFAR))
1015 		printk("CFAR: "REG" ", regs->orig_gpr3);
1016 	if (trap == 0x200 || trap == 0x300 || trap == 0x600)
1017 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
1018 		printk("DEAR: "REG" ESR: "REG" ", regs->dar, regs->dsisr);
1019 #else
1020 		printk("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr);
1021 #endif
1022 #ifdef CONFIG_PPC64
1023 	printk("SOFTE: %ld ", regs->softe);
1024 #endif
1025 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1026 	if (MSR_TM_ACTIVE(regs->msr))
1027 		printk("\nPACATMSCRATCH: %016llx ", get_paca()->tm_scratch);
1028 #endif
1029 
1030 	for (i = 0;  i < 32;  i++) {
1031 		if ((i % REGS_PER_LINE) == 0)
1032 			printk("\nGPR%02d: ", i);
1033 		printk(REG " ", regs->gpr[i]);
1034 		if (i == LAST_VOLATILE && !FULL_REGS(regs))
1035 			break;
1036 	}
1037 	printk("\n");
1038 #ifdef CONFIG_KALLSYMS
1039 	/*
1040 	 * Lookup NIP late so we have the best change of getting the
1041 	 * above info out without failing
1042 	 */
1043 	printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip);
1044 	printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link);
1045 #endif
1046 	show_stack(current, (unsigned long *) regs->gpr[1]);
1047 	if (!user_mode(regs))
1048 		show_instructions(regs);
1049 }
1050 
exit_thread(struct task_struct * tsk)1051 void exit_thread(struct task_struct *tsk)
1052 {
1053 	discard_lazy_cpu_state();
1054 }
1055 
flush_thread(void)1056 void flush_thread(void)
1057 {
1058 	discard_lazy_cpu_state();
1059 
1060 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1061 	flush_ptrace_hw_breakpoint(current);
1062 #else /* CONFIG_HAVE_HW_BREAKPOINT */
1063 	set_debug_reg_defaults(&current->thread);
1064 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
1065 }
1066 
1067 void
release_thread(struct task_struct * t)1068 release_thread(struct task_struct *t)
1069 {
1070 }
1071 
1072 /*
1073  * this gets called so that we can store coprocessor state into memory and
1074  * copy the current task into the new thread.
1075  */
arch_dup_task_struct(struct task_struct * dst,struct task_struct * src)1076 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
1077 {
1078 	flush_fp_to_thread(src);
1079 	flush_altivec_to_thread(src);
1080 	flush_vsx_to_thread(src);
1081 	flush_spe_to_thread(src);
1082 	/*
1083 	 * Flush TM state out so we can copy it.  __switch_to_tm() does this
1084 	 * flush but it removes the checkpointed state from the current CPU and
1085 	 * transitions the CPU out of TM mode.  Hence we need to call
1086 	 * tm_recheckpoint_new_task() (on the same task) to restore the
1087 	 * checkpointed state back and the TM mode.
1088 	 */
1089 	__switch_to_tm(src);
1090 	tm_recheckpoint_new_task(src);
1091 
1092 	*dst = *src;
1093 
1094 	clear_task_ebb(dst);
1095 
1096 	return 0;
1097 }
1098 
setup_ksp_vsid(struct task_struct * p,unsigned long sp)1099 static void setup_ksp_vsid(struct task_struct *p, unsigned long sp)
1100 {
1101 #ifdef CONFIG_PPC_STD_MMU_64
1102 	unsigned long sp_vsid;
1103 	unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
1104 
1105 	if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
1106 		sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T)
1107 			<< SLB_VSID_SHIFT_1T;
1108 	else
1109 		sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M)
1110 			<< SLB_VSID_SHIFT;
1111 	sp_vsid |= SLB_VSID_KERNEL | llp;
1112 	p->thread.ksp_vsid = sp_vsid;
1113 #endif
1114 }
1115 
1116 /*
1117  * Copy a thread..
1118  */
1119 extern unsigned long dscr_default; /* defined in arch/powerpc/kernel/sysfs.c */
1120 
copy_thread(unsigned long clone_flags,unsigned long usp,unsigned long arg,struct task_struct * p)1121 int copy_thread(unsigned long clone_flags, unsigned long usp,
1122 		unsigned long arg, struct task_struct *p)
1123 {
1124 	struct pt_regs *childregs, *kregs;
1125 	extern void ret_from_fork(void);
1126 	extern void ret_from_kernel_thread(void);
1127 	void (*f)(void);
1128 	unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
1129 
1130 	/* Copy registers */
1131 	sp -= sizeof(struct pt_regs);
1132 	childregs = (struct pt_regs *) sp;
1133 	if (unlikely(p->flags & PF_KTHREAD)) {
1134 		struct thread_info *ti = (void *)task_stack_page(p);
1135 		memset(childregs, 0, sizeof(struct pt_regs));
1136 		childregs->gpr[1] = sp + sizeof(struct pt_regs);
1137 		/* function */
1138 		if (usp)
1139 			childregs->gpr[14] = ppc_function_entry((void *)usp);
1140 #ifdef CONFIG_PPC64
1141 		clear_tsk_thread_flag(p, TIF_32BIT);
1142 		childregs->softe = 1;
1143 #endif
1144 		childregs->gpr[15] = arg;
1145 		p->thread.regs = NULL;	/* no user register state */
1146 		ti->flags |= _TIF_RESTOREALL;
1147 		f = ret_from_kernel_thread;
1148 	} else {
1149 		struct pt_regs *regs = current_pt_regs();
1150 		CHECK_FULL_REGS(regs);
1151 		*childregs = *regs;
1152 		if (usp)
1153 			childregs->gpr[1] = usp;
1154 		p->thread.regs = childregs;
1155 		childregs->gpr[3] = 0;  /* Result from fork() */
1156 		if (clone_flags & CLONE_SETTLS) {
1157 #ifdef CONFIG_PPC64
1158 			if (!is_32bit_task())
1159 				childregs->gpr[13] = childregs->gpr[6];
1160 			else
1161 #endif
1162 				childregs->gpr[2] = childregs->gpr[6];
1163 		}
1164 
1165 		f = ret_from_fork;
1166 	}
1167 	sp -= STACK_FRAME_OVERHEAD;
1168 
1169 	/*
1170 	 * The way this works is that at some point in the future
1171 	 * some task will call _switch to switch to the new task.
1172 	 * That will pop off the stack frame created below and start
1173 	 * the new task running at ret_from_fork.  The new task will
1174 	 * do some house keeping and then return from the fork or clone
1175 	 * system call, using the stack frame created above.
1176 	 */
1177 	((unsigned long *)sp)[0] = 0;
1178 	sp -= sizeof(struct pt_regs);
1179 	kregs = (struct pt_regs *) sp;
1180 	sp -= STACK_FRAME_OVERHEAD;
1181 	p->thread.ksp = sp;
1182 #ifdef CONFIG_PPC32
1183 	p->thread.ksp_limit = (unsigned long)task_stack_page(p) +
1184 				_ALIGN_UP(sizeof(struct thread_info), 16);
1185 #endif
1186 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1187 	p->thread.ptrace_bps[0] = NULL;
1188 #endif
1189 
1190 	p->thread.fp_save_area = NULL;
1191 #ifdef CONFIG_ALTIVEC
1192 	p->thread.vr_save_area = NULL;
1193 #endif
1194 
1195 	setup_ksp_vsid(p, sp);
1196 
1197 #ifdef CONFIG_PPC64
1198 	if (cpu_has_feature(CPU_FTR_DSCR)) {
1199 		p->thread.dscr_inherit = current->thread.dscr_inherit;
1200 		p->thread.dscr = current->thread.dscr;
1201 	}
1202 	if (cpu_has_feature(CPU_FTR_HAS_PPR))
1203 		p->thread.ppr = INIT_PPR;
1204 #endif
1205 	kregs->nip = ppc_function_entry(f);
1206 	return 0;
1207 }
1208 
1209 /*
1210  * Set up a thread for executing a new program
1211  */
start_thread(struct pt_regs * regs,unsigned long start,unsigned long sp)1212 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
1213 {
1214 #ifdef CONFIG_PPC64
1215 	unsigned long load_addr = regs->gpr[2];	/* saved by ELF_PLAT_INIT */
1216 #endif
1217 
1218 	/*
1219 	 * If we exec out of a kernel thread then thread.regs will not be
1220 	 * set.  Do it now.
1221 	 */
1222 	if (!current->thread.regs) {
1223 		struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
1224 		current->thread.regs = regs - 1;
1225 	}
1226 
1227 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1228 	/*
1229 	 * Clear any transactional state, we're exec()ing. The cause is
1230 	 * not important as there will never be a recheckpoint so it's not
1231 	 * user visible.
1232 	 */
1233 	if (MSR_TM_SUSPENDED(mfmsr()))
1234 		tm_reclaim_current(0);
1235 #endif
1236 
1237 	memset(regs->gpr, 0, sizeof(regs->gpr));
1238 	regs->ctr = 0;
1239 	regs->link = 0;
1240 	regs->xer = 0;
1241 	regs->ccr = 0;
1242 	regs->gpr[1] = sp;
1243 
1244 	/*
1245 	 * We have just cleared all the nonvolatile GPRs, so make
1246 	 * FULL_REGS(regs) return true.  This is necessary to allow
1247 	 * ptrace to examine the thread immediately after exec.
1248 	 */
1249 	regs->trap &= ~1UL;
1250 
1251 #ifdef CONFIG_PPC32
1252 	regs->mq = 0;
1253 	regs->nip = start;
1254 	regs->msr = MSR_USER;
1255 #else
1256 	if (!is_32bit_task()) {
1257 		unsigned long entry;
1258 
1259 		if (is_elf2_task()) {
1260 			/* Look ma, no function descriptors! */
1261 			entry = start;
1262 
1263 			/*
1264 			 * Ulrich says:
1265 			 *   The latest iteration of the ABI requires that when
1266 			 *   calling a function (at its global entry point),
1267 			 *   the caller must ensure r12 holds the entry point
1268 			 *   address (so that the function can quickly
1269 			 *   establish addressability).
1270 			 */
1271 			regs->gpr[12] = start;
1272 			/* Make sure that's restored on entry to userspace. */
1273 			set_thread_flag(TIF_RESTOREALL);
1274 		} else {
1275 			unsigned long toc;
1276 
1277 			/* start is a relocated pointer to the function
1278 			 * descriptor for the elf _start routine.  The first
1279 			 * entry in the function descriptor is the entry
1280 			 * address of _start and the second entry is the TOC
1281 			 * value we need to use.
1282 			 */
1283 			__get_user(entry, (unsigned long __user *)start);
1284 			__get_user(toc, (unsigned long __user *)start+1);
1285 
1286 			/* Check whether the e_entry function descriptor entries
1287 			 * need to be relocated before we can use them.
1288 			 */
1289 			if (load_addr != 0) {
1290 				entry += load_addr;
1291 				toc   += load_addr;
1292 			}
1293 			regs->gpr[2] = toc;
1294 		}
1295 		regs->nip = entry;
1296 		regs->msr = MSR_USER64;
1297 	} else {
1298 		regs->nip = start;
1299 		regs->gpr[2] = 0;
1300 		regs->msr = MSR_USER32;
1301 	}
1302 #endif
1303 	discard_lazy_cpu_state();
1304 #ifdef CONFIG_VSX
1305 	current->thread.used_vsr = 0;
1306 #endif
1307 	memset(&current->thread.fp_state, 0, sizeof(current->thread.fp_state));
1308 	current->thread.fp_save_area = NULL;
1309 #ifdef CONFIG_ALTIVEC
1310 	memset(&current->thread.vr_state, 0, sizeof(current->thread.vr_state));
1311 	current->thread.vr_state.vscr.u[3] = 0x00010000; /* Java mode disabled */
1312 	current->thread.vr_save_area = NULL;
1313 	current->thread.vrsave = 0;
1314 	current->thread.used_vr = 0;
1315 #endif /* CONFIG_ALTIVEC */
1316 #ifdef CONFIG_SPE
1317 	memset(current->thread.evr, 0, sizeof(current->thread.evr));
1318 	current->thread.acc = 0;
1319 	current->thread.spefscr = 0;
1320 	current->thread.used_spe = 0;
1321 #endif /* CONFIG_SPE */
1322 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1323 	if (cpu_has_feature(CPU_FTR_TM))
1324 		regs->msr |= MSR_TM;
1325 	current->thread.tm_tfhar = 0;
1326 	current->thread.tm_texasr = 0;
1327 	current->thread.tm_tfiar = 0;
1328 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
1329 }
1330 EXPORT_SYMBOL(start_thread);
1331 
1332 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
1333 		| PR_FP_EXC_RES | PR_FP_EXC_INV)
1334 
set_fpexc_mode(struct task_struct * tsk,unsigned int val)1335 int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
1336 {
1337 	struct pt_regs *regs = tsk->thread.regs;
1338 
1339 	/* This is a bit hairy.  If we are an SPE enabled  processor
1340 	 * (have embedded fp) we store the IEEE exception enable flags in
1341 	 * fpexc_mode.  fpexc_mode is also used for setting FP exception
1342 	 * mode (asyn, precise, disabled) for 'Classic' FP. */
1343 	if (val & PR_FP_EXC_SW_ENABLE) {
1344 #ifdef CONFIG_SPE
1345 		if (cpu_has_feature(CPU_FTR_SPE)) {
1346 			/*
1347 			 * When the sticky exception bits are set
1348 			 * directly by userspace, it must call prctl
1349 			 * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
1350 			 * in the existing prctl settings) or
1351 			 * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
1352 			 * the bits being set).  <fenv.h> functions
1353 			 * saving and restoring the whole
1354 			 * floating-point environment need to do so
1355 			 * anyway to restore the prctl settings from
1356 			 * the saved environment.
1357 			 */
1358 			tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
1359 			tsk->thread.fpexc_mode = val &
1360 				(PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
1361 			return 0;
1362 		} else {
1363 			return -EINVAL;
1364 		}
1365 #else
1366 		return -EINVAL;
1367 #endif
1368 	}
1369 
1370 	/* on a CONFIG_SPE this does not hurt us.  The bits that
1371 	 * __pack_fe01 use do not overlap with bits used for
1372 	 * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
1373 	 * on CONFIG_SPE implementations are reserved so writing to
1374 	 * them does not change anything */
1375 	if (val > PR_FP_EXC_PRECISE)
1376 		return -EINVAL;
1377 	tsk->thread.fpexc_mode = __pack_fe01(val);
1378 	if (regs != NULL && (regs->msr & MSR_FP) != 0)
1379 		regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
1380 			| tsk->thread.fpexc_mode;
1381 	return 0;
1382 }
1383 
get_fpexc_mode(struct task_struct * tsk,unsigned long adr)1384 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
1385 {
1386 	unsigned int val;
1387 
1388 	if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
1389 #ifdef CONFIG_SPE
1390 		if (cpu_has_feature(CPU_FTR_SPE)) {
1391 			/*
1392 			 * When the sticky exception bits are set
1393 			 * directly by userspace, it must call prctl
1394 			 * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
1395 			 * in the existing prctl settings) or
1396 			 * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
1397 			 * the bits being set).  <fenv.h> functions
1398 			 * saving and restoring the whole
1399 			 * floating-point environment need to do so
1400 			 * anyway to restore the prctl settings from
1401 			 * the saved environment.
1402 			 */
1403 			tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
1404 			val = tsk->thread.fpexc_mode;
1405 		} else
1406 			return -EINVAL;
1407 #else
1408 		return -EINVAL;
1409 #endif
1410 	else
1411 		val = __unpack_fe01(tsk->thread.fpexc_mode);
1412 	return put_user(val, (unsigned int __user *) adr);
1413 }
1414 
set_endian(struct task_struct * tsk,unsigned int val)1415 int set_endian(struct task_struct *tsk, unsigned int val)
1416 {
1417 	struct pt_regs *regs = tsk->thread.regs;
1418 
1419 	if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) ||
1420 	    (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE)))
1421 		return -EINVAL;
1422 
1423 	if (regs == NULL)
1424 		return -EINVAL;
1425 
1426 	if (val == PR_ENDIAN_BIG)
1427 		regs->msr &= ~MSR_LE;
1428 	else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
1429 		regs->msr |= MSR_LE;
1430 	else
1431 		return -EINVAL;
1432 
1433 	return 0;
1434 }
1435 
get_endian(struct task_struct * tsk,unsigned long adr)1436 int get_endian(struct task_struct *tsk, unsigned long adr)
1437 {
1438 	struct pt_regs *regs = tsk->thread.regs;
1439 	unsigned int val;
1440 
1441 	if (!cpu_has_feature(CPU_FTR_PPC_LE) &&
1442 	    !cpu_has_feature(CPU_FTR_REAL_LE))
1443 		return -EINVAL;
1444 
1445 	if (regs == NULL)
1446 		return -EINVAL;
1447 
1448 	if (regs->msr & MSR_LE) {
1449 		if (cpu_has_feature(CPU_FTR_REAL_LE))
1450 			val = PR_ENDIAN_LITTLE;
1451 		else
1452 			val = PR_ENDIAN_PPC_LITTLE;
1453 	} else
1454 		val = PR_ENDIAN_BIG;
1455 
1456 	return put_user(val, (unsigned int __user *)adr);
1457 }
1458 
set_unalign_ctl(struct task_struct * tsk,unsigned int val)1459 int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
1460 {
1461 	tsk->thread.align_ctl = val;
1462 	return 0;
1463 }
1464 
get_unalign_ctl(struct task_struct * tsk,unsigned long adr)1465 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
1466 {
1467 	return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
1468 }
1469 
valid_irq_stack(unsigned long sp,struct task_struct * p,unsigned long nbytes)1470 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
1471 				  unsigned long nbytes)
1472 {
1473 	unsigned long stack_page;
1474 	unsigned long cpu = task_cpu(p);
1475 
1476 	/*
1477 	 * Avoid crashing if the stack has overflowed and corrupted
1478 	 * task_cpu(p), which is in the thread_info struct.
1479 	 */
1480 	if (cpu < NR_CPUS && cpu_possible(cpu)) {
1481 		stack_page = (unsigned long) hardirq_ctx[cpu];
1482 		if (sp >= stack_page + sizeof(struct thread_struct)
1483 		    && sp <= stack_page + THREAD_SIZE - nbytes)
1484 			return 1;
1485 
1486 		stack_page = (unsigned long) softirq_ctx[cpu];
1487 		if (sp >= stack_page + sizeof(struct thread_struct)
1488 		    && sp <= stack_page + THREAD_SIZE - nbytes)
1489 			return 1;
1490 	}
1491 	return 0;
1492 }
1493 
validate_sp(unsigned long sp,struct task_struct * p,unsigned long nbytes)1494 int validate_sp(unsigned long sp, struct task_struct *p,
1495 		       unsigned long nbytes)
1496 {
1497 	unsigned long stack_page = (unsigned long)task_stack_page(p);
1498 
1499 	if (sp >= stack_page + sizeof(struct thread_struct)
1500 	    && sp <= stack_page + THREAD_SIZE - nbytes)
1501 		return 1;
1502 
1503 	return valid_irq_stack(sp, p, nbytes);
1504 }
1505 
1506 EXPORT_SYMBOL(validate_sp);
1507 
get_wchan(struct task_struct * p)1508 unsigned long get_wchan(struct task_struct *p)
1509 {
1510 	unsigned long ip, sp;
1511 	int count = 0;
1512 
1513 	if (!p || p == current || p->state == TASK_RUNNING)
1514 		return 0;
1515 
1516 	sp = p->thread.ksp;
1517 	if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
1518 		return 0;
1519 
1520 	do {
1521 		sp = *(unsigned long *)sp;
1522 		if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
1523 			return 0;
1524 		if (count > 0) {
1525 			ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE];
1526 			if (!in_sched_functions(ip))
1527 				return ip;
1528 		}
1529 	} while (count++ < 16);
1530 	return 0;
1531 }
1532 
1533 static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH;
1534 
show_stack(struct task_struct * tsk,unsigned long * stack)1535 void show_stack(struct task_struct *tsk, unsigned long *stack)
1536 {
1537 	unsigned long sp, ip, lr, newsp;
1538 	int count = 0;
1539 	int firstframe = 1;
1540 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1541 	int curr_frame = current->curr_ret_stack;
1542 	extern void return_to_handler(void);
1543 	unsigned long rth = (unsigned long)return_to_handler;
1544 	unsigned long mrth = -1;
1545 #ifdef CONFIG_PPC64
1546 	extern void mod_return_to_handler(void);
1547 	rth = *(unsigned long *)rth;
1548 	mrth = (unsigned long)mod_return_to_handler;
1549 	mrth = *(unsigned long *)mrth;
1550 #endif
1551 #endif
1552 
1553 	sp = (unsigned long) stack;
1554 	if (tsk == NULL)
1555 		tsk = current;
1556 	if (sp == 0) {
1557 		if (tsk == current)
1558 			sp = current_stack_pointer();
1559 		else
1560 			sp = tsk->thread.ksp;
1561 	}
1562 
1563 	lr = 0;
1564 	printk("Call Trace:\n");
1565 	do {
1566 		if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
1567 			return;
1568 
1569 		stack = (unsigned long *) sp;
1570 		newsp = stack[0];
1571 		ip = stack[STACK_FRAME_LR_SAVE];
1572 		if (!firstframe || ip != lr) {
1573 			printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip);
1574 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1575 			if ((ip == rth || ip == mrth) && curr_frame >= 0) {
1576 				printk(" (%pS)",
1577 				       (void *)current->ret_stack[curr_frame].ret);
1578 				curr_frame--;
1579 			}
1580 #endif
1581 			if (firstframe)
1582 				printk(" (unreliable)");
1583 			printk("\n");
1584 		}
1585 		firstframe = 0;
1586 
1587 		/*
1588 		 * See if this is an exception frame.
1589 		 * We look for the "regshere" marker in the current frame.
1590 		 */
1591 		if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE)
1592 		    && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
1593 			struct pt_regs *regs = (struct pt_regs *)
1594 				(sp + STACK_FRAME_OVERHEAD);
1595 			lr = regs->link;
1596 			printk("--- interrupt: %lx at %pS\n    LR = %pS\n",
1597 			       regs->trap, (void *)regs->nip, (void *)lr);
1598 			firstframe = 1;
1599 		}
1600 
1601 		sp = newsp;
1602 	} while (count++ < kstack_depth_to_print);
1603 }
1604 
1605 #ifdef CONFIG_PPC64
1606 /* Called with hard IRQs off */
__ppc64_runlatch_on(void)1607 void notrace __ppc64_runlatch_on(void)
1608 {
1609 	struct thread_info *ti = current_thread_info();
1610 	unsigned long ctrl;
1611 
1612 	ctrl = mfspr(SPRN_CTRLF);
1613 	ctrl |= CTRL_RUNLATCH;
1614 	mtspr(SPRN_CTRLT, ctrl);
1615 
1616 	ti->local_flags |= _TLF_RUNLATCH;
1617 }
1618 
1619 /* Called with hard IRQs off */
__ppc64_runlatch_off(void)1620 void notrace __ppc64_runlatch_off(void)
1621 {
1622 	struct thread_info *ti = current_thread_info();
1623 	unsigned long ctrl;
1624 
1625 	ti->local_flags &= ~_TLF_RUNLATCH;
1626 
1627 	ctrl = mfspr(SPRN_CTRLF);
1628 	ctrl &= ~CTRL_RUNLATCH;
1629 	mtspr(SPRN_CTRLT, ctrl);
1630 }
1631 #endif /* CONFIG_PPC64 */
1632 
arch_align_stack(unsigned long sp)1633 unsigned long arch_align_stack(unsigned long sp)
1634 {
1635 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
1636 		sp -= get_random_int() & ~PAGE_MASK;
1637 	return sp & ~0xf;
1638 }
1639 
brk_rnd(void)1640 static inline unsigned long brk_rnd(void)
1641 {
1642         unsigned long rnd = 0;
1643 
1644 	/* 8MB for 32bit, 1GB for 64bit */
1645 	if (is_32bit_task())
1646 		rnd = (get_random_long() % (1UL<<(23-PAGE_SHIFT)));
1647 	else
1648 		rnd = (get_random_long() % (1UL<<(30-PAGE_SHIFT)));
1649 
1650 	return rnd << PAGE_SHIFT;
1651 }
1652 
arch_randomize_brk(struct mm_struct * mm)1653 unsigned long arch_randomize_brk(struct mm_struct *mm)
1654 {
1655 	unsigned long base = mm->brk;
1656 	unsigned long ret;
1657 
1658 #ifdef CONFIG_PPC_STD_MMU_64
1659 	/*
1660 	 * If we are using 1TB segments and we are allowed to randomise
1661 	 * the heap, we can put it above 1TB so it is backed by a 1TB
1662 	 * segment. Otherwise the heap will be in the bottom 1TB
1663 	 * which always uses 256MB segments and this may result in a
1664 	 * performance penalty.
1665 	 */
1666 	if (!is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T))
1667 		base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T);
1668 #endif
1669 
1670 	ret = PAGE_ALIGN(base + brk_rnd());
1671 
1672 	if (ret < mm->brk)
1673 		return mm->brk;
1674 
1675 	return ret;
1676 }
1677 
randomize_et_dyn(unsigned long base)1678 unsigned long randomize_et_dyn(unsigned long base)
1679 {
1680 	unsigned long ret = PAGE_ALIGN(base + brk_rnd());
1681 
1682 	if (ret < base)
1683 		return base;
1684 
1685 	return ret;
1686 }
1687