2 * Derived from "arch/i386/kernel/process.c"
3 * Copyright (C) 1995 Linus Torvalds
5 * Updated and modified by Cort Dougan (cort@cs.nmt.edu) and
6 * Paul Mackerras (paulus@cs.anu.edu.au)
9 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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.
17 #include <linux/errno.h>
18 #include <linux/sched.h>
19 #include <linux/kernel.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 #include <linux/uaccess.h>
41 #include <linux/elf-randomize.h>
43 #include <asm/pgtable.h>
45 #include <asm/processor.h>
48 #include <asm/machdep.h>
50 #include <asm/runlatch.h>
51 #include <asm/syscalls.h>
52 #include <asm/switch_to.h>
54 #include <asm/debug.h>
56 #include <asm/firmware.h>
58 #include <asm/code-patching.h>
60 #include <asm/livepatch.h>
61 #include <asm/cpu_has_feature.h>
63 #include <linux/kprobes.h>
64 #include <linux/kdebug.h>
66 /* Transactional Memory debug */
68 #define TM_DEBUG(x...) printk(KERN_INFO x)
70 #define TM_DEBUG(x...) do { } while(0)
73 extern unsigned long _get_SP(void);
75 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
76 static void check_if_tm_restore_required(struct task_struct *tsk)
79 * If we are saving the current thread's registers, and the
80 * thread is in a transactional state, set the TIF_RESTORE_TM
81 * bit so that we know to restore the registers before
82 * returning to userspace.
84 if (tsk == current && tsk->thread.regs &&
85 MSR_TM_ACTIVE(tsk->thread.regs->msr) &&
86 !test_thread_flag(TIF_RESTORE_TM)) {
87 tsk->thread.ckpt_regs.msr = tsk->thread.regs->msr;
88 set_thread_flag(TIF_RESTORE_TM);
92 static inline void check_if_tm_restore_required(struct task_struct *tsk) { }
93 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
95 bool strict_msr_control;
96 EXPORT_SYMBOL(strict_msr_control);
98 static int __init enable_strict_msr_control(char *str)
100 strict_msr_control = true;
101 pr_info("Enabling strict facility control\n");
105 early_param("ppc_strict_facility_enable", enable_strict_msr_control);
107 void msr_check_and_set(unsigned long bits)
109 unsigned long oldmsr = mfmsr();
110 unsigned long newmsr;
112 newmsr = oldmsr | bits;
115 if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
119 if (oldmsr != newmsr)
123 void __msr_check_and_clear(unsigned long bits)
125 unsigned long oldmsr = mfmsr();
126 unsigned long newmsr;
128 newmsr = oldmsr & ~bits;
131 if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
135 if (oldmsr != newmsr)
138 EXPORT_SYMBOL(__msr_check_and_clear);
140 #ifdef CONFIG_PPC_FPU
141 void __giveup_fpu(struct task_struct *tsk)
146 msr = tsk->thread.regs->msr;
149 if (cpu_has_feature(CPU_FTR_VSX))
152 tsk->thread.regs->msr = msr;
155 void giveup_fpu(struct task_struct *tsk)
157 check_if_tm_restore_required(tsk);
159 msr_check_and_set(MSR_FP);
161 msr_check_and_clear(MSR_FP);
163 EXPORT_SYMBOL(giveup_fpu);
166 * Make sure the floating-point register state in the
167 * the thread_struct is up to date for task tsk.
169 void flush_fp_to_thread(struct task_struct *tsk)
171 if (tsk->thread.regs) {
173 * We need to disable preemption here because if we didn't,
174 * another process could get scheduled after the regs->msr
175 * test but before we have finished saving the FP registers
176 * to the thread_struct. That process could take over the
177 * FPU, and then when we get scheduled again we would store
178 * bogus values for the remaining FP registers.
181 if (tsk->thread.regs->msr & MSR_FP) {
183 * This should only ever be called for current or
184 * for a stopped child process. Since we save away
185 * the FP register state on context switch,
186 * there is something wrong if a stopped child appears
187 * to still have its FP state in the CPU registers.
189 BUG_ON(tsk != current);
195 EXPORT_SYMBOL_GPL(flush_fp_to_thread);
197 void enable_kernel_fp(void)
199 WARN_ON(preemptible());
201 msr_check_and_set(MSR_FP);
203 if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) {
204 check_if_tm_restore_required(current);
205 __giveup_fpu(current);
208 EXPORT_SYMBOL(enable_kernel_fp);
210 static int restore_fp(struct task_struct *tsk) {
211 if (tsk->thread.load_fp) {
212 load_fp_state(¤t->thread.fp_state);
213 current->thread.load_fp++;
219 static int restore_fp(struct task_struct *tsk) { return 0; }
220 #endif /* CONFIG_PPC_FPU */
222 #ifdef CONFIG_ALTIVEC
223 #define loadvec(thr) ((thr).load_vec)
225 static void __giveup_altivec(struct task_struct *tsk)
230 msr = tsk->thread.regs->msr;
233 if (cpu_has_feature(CPU_FTR_VSX))
236 tsk->thread.regs->msr = msr;
239 void giveup_altivec(struct task_struct *tsk)
241 check_if_tm_restore_required(tsk);
243 msr_check_and_set(MSR_VEC);
244 __giveup_altivec(tsk);
245 msr_check_and_clear(MSR_VEC);
247 EXPORT_SYMBOL(giveup_altivec);
249 void enable_kernel_altivec(void)
251 WARN_ON(preemptible());
253 msr_check_and_set(MSR_VEC);
255 if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) {
256 check_if_tm_restore_required(current);
257 __giveup_altivec(current);
260 EXPORT_SYMBOL(enable_kernel_altivec);
263 * Make sure the VMX/Altivec register state in the
264 * the thread_struct is up to date for task tsk.
266 void flush_altivec_to_thread(struct task_struct *tsk)
268 if (tsk->thread.regs) {
270 if (tsk->thread.regs->msr & MSR_VEC) {
271 BUG_ON(tsk != current);
277 EXPORT_SYMBOL_GPL(flush_altivec_to_thread);
279 static int restore_altivec(struct task_struct *tsk)
281 if (cpu_has_feature(CPU_FTR_ALTIVEC) && tsk->thread.load_vec) {
282 load_vr_state(&tsk->thread.vr_state);
283 tsk->thread.used_vr = 1;
284 tsk->thread.load_vec++;
291 #define loadvec(thr) 0
292 static inline int restore_altivec(struct task_struct *tsk) { return 0; }
293 #endif /* CONFIG_ALTIVEC */
296 static void __giveup_vsx(struct task_struct *tsk)
298 if (tsk->thread.regs->msr & MSR_FP)
300 if (tsk->thread.regs->msr & MSR_VEC)
301 __giveup_altivec(tsk);
302 tsk->thread.regs->msr &= ~MSR_VSX;
305 static void giveup_vsx(struct task_struct *tsk)
307 check_if_tm_restore_required(tsk);
309 msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
311 msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX);
314 static void save_vsx(struct task_struct *tsk)
316 if (tsk->thread.regs->msr & MSR_FP)
318 if (tsk->thread.regs->msr & MSR_VEC)
322 void enable_kernel_vsx(void)
324 WARN_ON(preemptible());
326 msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
328 if (current->thread.regs && (current->thread.regs->msr & MSR_VSX)) {
329 check_if_tm_restore_required(current);
330 if (current->thread.regs->msr & MSR_FP)
331 __giveup_fpu(current);
332 if (current->thread.regs->msr & MSR_VEC)
333 __giveup_altivec(current);
334 __giveup_vsx(current);
337 EXPORT_SYMBOL(enable_kernel_vsx);
339 void flush_vsx_to_thread(struct task_struct *tsk)
341 if (tsk->thread.regs) {
343 if (tsk->thread.regs->msr & MSR_VSX) {
344 BUG_ON(tsk != current);
350 EXPORT_SYMBOL_GPL(flush_vsx_to_thread);
352 static int restore_vsx(struct task_struct *tsk)
354 if (cpu_has_feature(CPU_FTR_VSX)) {
355 tsk->thread.used_vsr = 1;
362 static inline int restore_vsx(struct task_struct *tsk) { return 0; }
363 static inline void save_vsx(struct task_struct *tsk) { }
364 #endif /* CONFIG_VSX */
367 void giveup_spe(struct task_struct *tsk)
369 check_if_tm_restore_required(tsk);
371 msr_check_and_set(MSR_SPE);
373 msr_check_and_clear(MSR_SPE);
375 EXPORT_SYMBOL(giveup_spe);
377 void enable_kernel_spe(void)
379 WARN_ON(preemptible());
381 msr_check_and_set(MSR_SPE);
383 if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) {
384 check_if_tm_restore_required(current);
385 __giveup_spe(current);
388 EXPORT_SYMBOL(enable_kernel_spe);
390 void flush_spe_to_thread(struct task_struct *tsk)
392 if (tsk->thread.regs) {
394 if (tsk->thread.regs->msr & MSR_SPE) {
395 BUG_ON(tsk != current);
396 tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
402 #endif /* CONFIG_SPE */
404 static unsigned long msr_all_available;
406 static int __init init_msr_all_available(void)
408 #ifdef CONFIG_PPC_FPU
409 msr_all_available |= MSR_FP;
411 #ifdef CONFIG_ALTIVEC
412 if (cpu_has_feature(CPU_FTR_ALTIVEC))
413 msr_all_available |= MSR_VEC;
416 if (cpu_has_feature(CPU_FTR_VSX))
417 msr_all_available |= MSR_VSX;
420 if (cpu_has_feature(CPU_FTR_SPE))
421 msr_all_available |= MSR_SPE;
426 early_initcall(init_msr_all_available);
428 void giveup_all(struct task_struct *tsk)
430 unsigned long usermsr;
432 if (!tsk->thread.regs)
435 usermsr = tsk->thread.regs->msr;
437 if ((usermsr & msr_all_available) == 0)
440 msr_check_and_set(msr_all_available);
442 #ifdef CONFIG_PPC_FPU
443 if (usermsr & MSR_FP)
446 #ifdef CONFIG_ALTIVEC
447 if (usermsr & MSR_VEC)
448 __giveup_altivec(tsk);
451 if (usermsr & MSR_VSX)
455 if (usermsr & MSR_SPE)
459 msr_check_and_clear(msr_all_available);
461 EXPORT_SYMBOL(giveup_all);
463 void restore_math(struct pt_regs *regs)
467 if (!current->thread.load_fp && !loadvec(current->thread))
471 msr_check_and_set(msr_all_available);
474 * Only reload if the bit is not set in the user MSR, the bit BEING set
475 * indicates that the registers are hot
477 if ((!(msr & MSR_FP)) && restore_fp(current))
478 msr |= MSR_FP | current->thread.fpexc_mode;
480 if ((!(msr & MSR_VEC)) && restore_altivec(current))
483 if ((msr & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC) &&
484 restore_vsx(current)) {
488 msr_check_and_clear(msr_all_available);
493 void save_all(struct task_struct *tsk)
495 unsigned long usermsr;
497 if (!tsk->thread.regs)
500 usermsr = tsk->thread.regs->msr;
502 if ((usermsr & msr_all_available) == 0)
505 msr_check_and_set(msr_all_available);
508 * Saving the way the register space is in hardware, save_vsx boils
509 * down to a save_fpu() and save_altivec()
511 if (usermsr & MSR_VSX) {
514 if (usermsr & MSR_FP)
517 if (usermsr & MSR_VEC)
521 if (usermsr & MSR_SPE)
524 msr_check_and_clear(msr_all_available);
527 void flush_all_to_thread(struct task_struct *tsk)
529 if (tsk->thread.regs) {
531 BUG_ON(tsk != current);
535 if (tsk->thread.regs->msr & MSR_SPE)
536 tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
542 EXPORT_SYMBOL(flush_all_to_thread);
544 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
545 void do_send_trap(struct pt_regs *regs, unsigned long address,
546 unsigned long error_code, int signal_code, int breakpt)
550 current->thread.trap_nr = signal_code;
551 if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
552 11, SIGSEGV) == NOTIFY_STOP)
555 /* Deliver the signal to userspace */
556 info.si_signo = SIGTRAP;
557 info.si_errno = breakpt; /* breakpoint or watchpoint id */
558 info.si_code = signal_code;
559 info.si_addr = (void __user *)address;
560 force_sig_info(SIGTRAP, &info, current);
562 #else /* !CONFIG_PPC_ADV_DEBUG_REGS */
563 void do_break (struct pt_regs *regs, unsigned long address,
564 unsigned long error_code)
568 current->thread.trap_nr = TRAP_HWBKPT;
569 if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
570 11, SIGSEGV) == NOTIFY_STOP)
573 if (debugger_break_match(regs))
576 /* Clear the breakpoint */
577 hw_breakpoint_disable();
579 /* Deliver the signal to userspace */
580 info.si_signo = SIGTRAP;
582 info.si_code = TRAP_HWBKPT;
583 info.si_addr = (void __user *)address;
584 force_sig_info(SIGTRAP, &info, current);
586 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
588 static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk);
590 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
592 * Set the debug registers back to their default "safe" values.
594 static void set_debug_reg_defaults(struct thread_struct *thread)
596 thread->debug.iac1 = thread->debug.iac2 = 0;
597 #if CONFIG_PPC_ADV_DEBUG_IACS > 2
598 thread->debug.iac3 = thread->debug.iac4 = 0;
600 thread->debug.dac1 = thread->debug.dac2 = 0;
601 #if CONFIG_PPC_ADV_DEBUG_DVCS > 0
602 thread->debug.dvc1 = thread->debug.dvc2 = 0;
604 thread->debug.dbcr0 = 0;
607 * Force User/Supervisor bits to b11 (user-only MSR[PR]=1)
609 thread->debug.dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US |
610 DBCR1_IAC3US | DBCR1_IAC4US;
612 * Force Data Address Compare User/Supervisor bits to be User-only
613 * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0.
615 thread->debug.dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US;
617 thread->debug.dbcr1 = 0;
621 static void prime_debug_regs(struct debug_reg *debug)
624 * We could have inherited MSR_DE from userspace, since
625 * it doesn't get cleared on exception entry. Make sure
626 * MSR_DE is clear before we enable any debug events.
628 mtmsr(mfmsr() & ~MSR_DE);
630 mtspr(SPRN_IAC1, debug->iac1);
631 mtspr(SPRN_IAC2, debug->iac2);
632 #if CONFIG_PPC_ADV_DEBUG_IACS > 2
633 mtspr(SPRN_IAC3, debug->iac3);
634 mtspr(SPRN_IAC4, debug->iac4);
636 mtspr(SPRN_DAC1, debug->dac1);
637 mtspr(SPRN_DAC2, debug->dac2);
638 #if CONFIG_PPC_ADV_DEBUG_DVCS > 0
639 mtspr(SPRN_DVC1, debug->dvc1);
640 mtspr(SPRN_DVC2, debug->dvc2);
642 mtspr(SPRN_DBCR0, debug->dbcr0);
643 mtspr(SPRN_DBCR1, debug->dbcr1);
645 mtspr(SPRN_DBCR2, debug->dbcr2);
649 * Unless neither the old or new thread are making use of the
650 * debug registers, set the debug registers from the values
651 * stored in the new thread.
653 void switch_booke_debug_regs(struct debug_reg *new_debug)
655 if ((current->thread.debug.dbcr0 & DBCR0_IDM)
656 || (new_debug->dbcr0 & DBCR0_IDM))
657 prime_debug_regs(new_debug);
659 EXPORT_SYMBOL_GPL(switch_booke_debug_regs);
660 #else /* !CONFIG_PPC_ADV_DEBUG_REGS */
661 #ifndef CONFIG_HAVE_HW_BREAKPOINT
662 static void set_debug_reg_defaults(struct thread_struct *thread)
664 thread->hw_brk.address = 0;
665 thread->hw_brk.type = 0;
666 set_breakpoint(&thread->hw_brk);
668 #endif /* !CONFIG_HAVE_HW_BREAKPOINT */
669 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
671 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
672 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
674 mtspr(SPRN_DAC1, dabr);
675 #ifdef CONFIG_PPC_47x
680 #elif defined(CONFIG_PPC_BOOK3S)
681 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
683 mtspr(SPRN_DABR, dabr);
684 if (cpu_has_feature(CPU_FTR_DABRX))
685 mtspr(SPRN_DABRX, dabrx);
689 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
695 static inline int set_dabr(struct arch_hw_breakpoint *brk)
697 unsigned long dabr, dabrx;
699 dabr = brk->address | (brk->type & HW_BRK_TYPE_DABR);
700 dabrx = ((brk->type >> 3) & 0x7);
703 return ppc_md.set_dabr(dabr, dabrx);
705 return __set_dabr(dabr, dabrx);
708 static inline int set_dawr(struct arch_hw_breakpoint *brk)
710 unsigned long dawr, dawrx, mrd;
714 dawrx = (brk->type & (HW_BRK_TYPE_READ | HW_BRK_TYPE_WRITE)) \
715 << (63 - 58); //* read/write bits */
716 dawrx |= ((brk->type & (HW_BRK_TYPE_TRANSLATE)) >> 2) \
717 << (63 - 59); //* translate */
718 dawrx |= (brk->type & (HW_BRK_TYPE_PRIV_ALL)) \
719 >> 3; //* PRIM bits */
720 /* dawr length is stored in field MDR bits 48:53. Matches range in
721 doublewords (64 bits) baised by -1 eg. 0b000000=1DW and
723 brk->len is in bytes.
724 This aligns up to double word size, shifts and does the bias.
726 mrd = ((brk->len + 7) >> 3) - 1;
727 dawrx |= (mrd & 0x3f) << (63 - 53);
730 return ppc_md.set_dawr(dawr, dawrx);
731 mtspr(SPRN_DAWR, dawr);
732 mtspr(SPRN_DAWRX, dawrx);
736 void __set_breakpoint(struct arch_hw_breakpoint *brk)
738 memcpy(this_cpu_ptr(¤t_brk), brk, sizeof(*brk));
740 if (cpu_has_feature(CPU_FTR_DAWR))
746 void set_breakpoint(struct arch_hw_breakpoint *brk)
749 __set_breakpoint(brk);
754 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
757 static inline bool hw_brk_match(struct arch_hw_breakpoint *a,
758 struct arch_hw_breakpoint *b)
760 if (a->address != b->address)
762 if (a->type != b->type)
764 if (a->len != b->len)
769 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
770 static void tm_reclaim_thread(struct thread_struct *thr,
771 struct thread_info *ti, uint8_t cause)
773 unsigned long msr_diff = 0;
776 * If FP/VSX registers have been already saved to the
777 * thread_struct, move them to the transact_fp array.
778 * We clear the TIF_RESTORE_TM bit since after the reclaim
779 * the thread will no longer be transactional.
781 if (test_ti_thread_flag(ti, TIF_RESTORE_TM)) {
782 msr_diff = thr->ckpt_regs.msr & ~thr->regs->msr;
783 if (msr_diff & MSR_FP)
784 memcpy(&thr->transact_fp, &thr->fp_state,
785 sizeof(struct thread_fp_state));
786 if (msr_diff & MSR_VEC)
787 memcpy(&thr->transact_vr, &thr->vr_state,
788 sizeof(struct thread_vr_state));
789 clear_ti_thread_flag(ti, TIF_RESTORE_TM);
790 msr_diff &= MSR_FP | MSR_VEC | MSR_VSX | MSR_FE0 | MSR_FE1;
794 * Use the current MSR TM suspended bit to track if we have
795 * checkpointed state outstanding.
796 * On signal delivery, we'd normally reclaim the checkpointed
797 * state to obtain stack pointer (see:get_tm_stackpointer()).
798 * This will then directly return to userspace without going
799 * through __switch_to(). However, if the stack frame is bad,
800 * we need to exit this thread which calls __switch_to() which
801 * will again attempt to reclaim the already saved tm state.
802 * Hence we need to check that we've not already reclaimed
804 * We do this using the current MSR, rather tracking it in
805 * some specific thread_struct bit, as it has the additional
806 * benefit of checking for a potential TM bad thing exception.
808 if (!MSR_TM_SUSPENDED(mfmsr()))
811 tm_reclaim(thr, thr->regs->msr, cause);
813 /* Having done the reclaim, we now have the checkpointed
814 * FP/VSX values in the registers. These might be valid
815 * even if we have previously called enable_kernel_fp() or
816 * flush_fp_to_thread(), so update thr->regs->msr to
817 * indicate their current validity.
819 thr->regs->msr |= msr_diff;
822 void tm_reclaim_current(uint8_t cause)
825 tm_reclaim_thread(¤t->thread, current_thread_info(), cause);
828 static inline void tm_reclaim_task(struct task_struct *tsk)
830 /* We have to work out if we're switching from/to a task that's in the
831 * middle of a transaction.
833 * In switching we need to maintain a 2nd register state as
834 * oldtask->thread.ckpt_regs. We tm_reclaim(oldproc); this saves the
835 * checkpointed (tbegin) state in ckpt_regs and saves the transactional
836 * (current) FPRs into oldtask->thread.transact_fpr[].
838 * We also context switch (save) TFHAR/TEXASR/TFIAR in here.
840 struct thread_struct *thr = &tsk->thread;
845 if (!MSR_TM_ACTIVE(thr->regs->msr))
846 goto out_and_saveregs;
848 /* Stash the original thread MSR, as giveup_fpu et al will
849 * modify it. We hold onto it to see whether the task used
850 * FP & vector regs. If the TIF_RESTORE_TM flag is set,
851 * ckpt_regs.msr is already set.
853 if (!test_ti_thread_flag(task_thread_info(tsk), TIF_RESTORE_TM))
854 thr->ckpt_regs.msr = thr->regs->msr;
856 TM_DEBUG("--- tm_reclaim on pid %d (NIP=%lx, "
857 "ccr=%lx, msr=%lx, trap=%lx)\n",
858 tsk->pid, thr->regs->nip,
859 thr->regs->ccr, thr->regs->msr,
862 tm_reclaim_thread(thr, task_thread_info(tsk), TM_CAUSE_RESCHED);
864 TM_DEBUG("--- tm_reclaim on pid %d complete\n",
868 /* Always save the regs here, even if a transaction's not active.
869 * This context-switches a thread's TM info SPRs. We do it here to
870 * be consistent with the restore path (in recheckpoint) which
871 * cannot happen later in _switch().
876 extern void __tm_recheckpoint(struct thread_struct *thread,
877 unsigned long orig_msr);
879 void tm_recheckpoint(struct thread_struct *thread,
880 unsigned long orig_msr)
884 /* We really can't be interrupted here as the TEXASR registers can't
885 * change and later in the trecheckpoint code, we have a userspace R1.
886 * So let's hard disable over this region.
888 local_irq_save(flags);
891 /* The TM SPRs are restored here, so that TEXASR.FS can be set
892 * before the trecheckpoint and no explosion occurs.
894 tm_restore_sprs(thread);
896 __tm_recheckpoint(thread, orig_msr);
898 local_irq_restore(flags);
901 static inline void tm_recheckpoint_new_task(struct task_struct *new)
905 if (!cpu_has_feature(CPU_FTR_TM))
908 /* Recheckpoint the registers of the thread we're about to switch to.
910 * If the task was using FP, we non-lazily reload both the original and
911 * the speculative FP register states. This is because the kernel
912 * doesn't see if/when a TM rollback occurs, so if we take an FP
913 * unavoidable later, we are unable to determine which set of FP regs
914 * need to be restored.
916 if (!new->thread.regs)
919 if (!MSR_TM_ACTIVE(new->thread.regs->msr)){
920 tm_restore_sprs(&new->thread);
923 msr = new->thread.ckpt_regs.msr;
924 /* Recheckpoint to restore original checkpointed register state. */
925 TM_DEBUG("*** tm_recheckpoint of pid %d "
926 "(new->msr 0x%lx, new->origmsr 0x%lx)\n",
927 new->pid, new->thread.regs->msr, msr);
929 /* This loads the checkpointed FP/VEC state, if used */
930 tm_recheckpoint(&new->thread, msr);
932 /* This loads the speculative FP/VEC state, if used */
934 do_load_up_transact_fpu(&new->thread);
935 new->thread.regs->msr |=
936 (MSR_FP | new->thread.fpexc_mode);
938 #ifdef CONFIG_ALTIVEC
940 do_load_up_transact_altivec(&new->thread);
941 new->thread.regs->msr |= MSR_VEC;
944 /* We may as well turn on VSX too since all the state is restored now */
946 new->thread.regs->msr |= MSR_VSX;
948 TM_DEBUG("*** tm_recheckpoint of pid %d complete "
949 "(kernel msr 0x%lx)\n",
953 static inline void __switch_to_tm(struct task_struct *prev)
955 if (cpu_has_feature(CPU_FTR_TM)) {
957 tm_reclaim_task(prev);
962 * This is called if we are on the way out to userspace and the
963 * TIF_RESTORE_TM flag is set. It checks if we need to reload
964 * FP and/or vector state and does so if necessary.
965 * If userspace is inside a transaction (whether active or
966 * suspended) and FP/VMX/VSX instructions have ever been enabled
967 * inside that transaction, then we have to keep them enabled
968 * and keep the FP/VMX/VSX state loaded while ever the transaction
969 * continues. The reason is that if we didn't, and subsequently
970 * got a FP/VMX/VSX unavailable interrupt inside a transaction,
971 * we don't know whether it's the same transaction, and thus we
972 * don't know which of the checkpointed state and the transactional
975 void restore_tm_state(struct pt_regs *regs)
977 unsigned long msr_diff;
979 clear_thread_flag(TIF_RESTORE_TM);
980 if (!MSR_TM_ACTIVE(regs->msr))
983 msr_diff = current->thread.ckpt_regs.msr & ~regs->msr;
984 msr_diff &= MSR_FP | MSR_VEC | MSR_VSX;
988 regs->msr |= msr_diff;
992 #define tm_recheckpoint_new_task(new)
993 #define __switch_to_tm(prev)
994 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
996 static inline void save_sprs(struct thread_struct *t)
998 #ifdef CONFIG_ALTIVEC
999 if (cpu_has_feature(CPU_FTR_ALTIVEC))
1000 t->vrsave = mfspr(SPRN_VRSAVE);
1002 #ifdef CONFIG_PPC_BOOK3S_64
1003 if (cpu_has_feature(CPU_FTR_DSCR))
1004 t->dscr = mfspr(SPRN_DSCR);
1006 if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
1007 t->bescr = mfspr(SPRN_BESCR);
1008 t->ebbhr = mfspr(SPRN_EBBHR);
1009 t->ebbrr = mfspr(SPRN_EBBRR);
1011 t->fscr = mfspr(SPRN_FSCR);
1014 * Note that the TAR is not available for use in the kernel.
1015 * (To provide this, the TAR should be backed up/restored on
1016 * exception entry/exit instead, and be in pt_regs. FIXME,
1017 * this should be in pt_regs anyway (for debug).)
1019 t->tar = mfspr(SPRN_TAR);
1022 if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1023 /* Conditionally save Load Monitor registers, if enabled */
1024 if (t->fscr & FSCR_LM) {
1025 t->lmrr = mfspr(SPRN_LMRR);
1026 t->lmser = mfspr(SPRN_LMSER);
1032 static inline void restore_sprs(struct thread_struct *old_thread,
1033 struct thread_struct *new_thread)
1035 #ifdef CONFIG_ALTIVEC
1036 if (cpu_has_feature(CPU_FTR_ALTIVEC) &&
1037 old_thread->vrsave != new_thread->vrsave)
1038 mtspr(SPRN_VRSAVE, new_thread->vrsave);
1040 #ifdef CONFIG_PPC_BOOK3S_64
1041 if (cpu_has_feature(CPU_FTR_DSCR)) {
1042 u64 dscr = get_paca()->dscr_default;
1043 if (new_thread->dscr_inherit)
1044 dscr = new_thread->dscr;
1046 if (old_thread->dscr != dscr)
1047 mtspr(SPRN_DSCR, dscr);
1050 if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
1051 if (old_thread->bescr != new_thread->bescr)
1052 mtspr(SPRN_BESCR, new_thread->bescr);
1053 if (old_thread->ebbhr != new_thread->ebbhr)
1054 mtspr(SPRN_EBBHR, new_thread->ebbhr);
1055 if (old_thread->ebbrr != new_thread->ebbrr)
1056 mtspr(SPRN_EBBRR, new_thread->ebbrr);
1058 if (old_thread->fscr != new_thread->fscr)
1059 mtspr(SPRN_FSCR, new_thread->fscr);
1061 if (old_thread->tar != new_thread->tar)
1062 mtspr(SPRN_TAR, new_thread->tar);
1065 if (cpu_has_feature(CPU_FTR_ARCH_300)) {
1066 /* Conditionally restore Load Monitor registers, if enabled */
1067 if (new_thread->fscr & FSCR_LM) {
1068 if (old_thread->lmrr != new_thread->lmrr)
1069 mtspr(SPRN_LMRR, new_thread->lmrr);
1070 if (old_thread->lmser != new_thread->lmser)
1071 mtspr(SPRN_LMSER, new_thread->lmser);
1077 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1078 void flush_tmregs_to_thread(struct task_struct *tsk)
1081 * Process self tracing is not yet supported through
1082 * ptrace interface. Ptrace generic code should have
1083 * prevented this from happening in the first place.
1084 * Warn once here with the message, if some how it
1087 WARN_ONCE(tsk == current,
1088 "Not expecting ptrace on self: TM regs may be incorrect\n");
1091 * If task is not current, it should have been flushed
1092 * already to it's thread_struct during __switch_to().
1097 struct task_struct *__switch_to(struct task_struct *prev,
1098 struct task_struct *new)
1100 struct thread_struct *new_thread, *old_thread;
1101 struct task_struct *last;
1102 #ifdef CONFIG_PPC_BOOK3S_64
1103 struct ppc64_tlb_batch *batch;
1106 new_thread = &new->thread;
1107 old_thread = ¤t->thread;
1109 WARN_ON(!irqs_disabled());
1113 * Collect processor utilization data per process
1115 if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
1116 struct cpu_usage *cu = this_cpu_ptr(&cpu_usage_array);
1117 long unsigned start_tb, current_tb;
1118 start_tb = old_thread->start_tb;
1119 cu->current_tb = current_tb = mfspr(SPRN_PURR);
1120 old_thread->accum_tb += (current_tb - start_tb);
1121 new_thread->start_tb = current_tb;
1123 #endif /* CONFIG_PPC64 */
1125 #ifdef CONFIG_PPC_STD_MMU_64
1126 batch = this_cpu_ptr(&ppc64_tlb_batch);
1127 if (batch->active) {
1128 current_thread_info()->local_flags |= _TLF_LAZY_MMU;
1130 __flush_tlb_pending(batch);
1133 #endif /* CONFIG_PPC_STD_MMU_64 */
1135 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
1136 switch_booke_debug_regs(&new->thread.debug);
1139 * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would
1142 #ifndef CONFIG_HAVE_HW_BREAKPOINT
1143 if (unlikely(!hw_brk_match(this_cpu_ptr(¤t_brk), &new->thread.hw_brk)))
1144 __set_breakpoint(&new->thread.hw_brk);
1145 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
1149 * We need to save SPRs before treclaim/trecheckpoint as these will
1150 * change a number of them.
1152 save_sprs(&prev->thread);
1154 __switch_to_tm(prev);
1156 /* Save FPU, Altivec, VSX and SPE state */
1160 * We can't take a PMU exception inside _switch() since there is a
1161 * window where the kernel stack SLB and the kernel stack are out
1162 * of sync. Hard disable here.
1166 tm_recheckpoint_new_task(new);
1169 * Call restore_sprs() before calling _switch(). If we move it after
1170 * _switch() then we miss out on calling it for new tasks. The reason
1171 * for this is we manually create a stack frame for new tasks that
1172 * directly returns through ret_from_fork() or
1173 * ret_from_kernel_thread(). See copy_thread() for details.
1175 restore_sprs(old_thread, new_thread);
1177 last = _switch(old_thread, new_thread);
1179 #ifdef CONFIG_PPC_STD_MMU_64
1180 if (current_thread_info()->local_flags & _TLF_LAZY_MMU) {
1181 current_thread_info()->local_flags &= ~_TLF_LAZY_MMU;
1182 batch = this_cpu_ptr(&ppc64_tlb_batch);
1186 if (current_thread_info()->task->thread.regs)
1187 restore_math(current_thread_info()->task->thread.regs);
1188 #endif /* CONFIG_PPC_STD_MMU_64 */
1193 static int instructions_to_print = 16;
1195 static void show_instructions(struct pt_regs *regs)
1198 unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
1201 printk("Instruction dump:");
1203 for (i = 0; i < instructions_to_print; i++) {
1209 #if !defined(CONFIG_BOOKE)
1210 /* If executing with the IMMU off, adjust pc rather
1211 * than print XXXXXXXX.
1213 if (!(regs->msr & MSR_IR))
1214 pc = (unsigned long)phys_to_virt(pc);
1217 if (!__kernel_text_address(pc) ||
1218 probe_kernel_address((unsigned int __user *)pc, instr)) {
1219 printk(KERN_CONT "XXXXXXXX ");
1221 if (regs->nip == pc)
1222 printk(KERN_CONT "<%08x> ", instr);
1224 printk(KERN_CONT "%08x ", instr);
1238 static struct regbit msr_bits[] = {
1239 #if defined(CONFIG_PPC64) && !defined(CONFIG_BOOKE)
1261 #ifndef CONFIG_BOOKE
1268 static void print_bits(unsigned long val, struct regbit *bits, const char *sep)
1272 for (; bits->bit; ++bits)
1273 if (val & bits->bit) {
1274 printk("%s%s", s, bits->name);
1279 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1280 static struct regbit msr_tm_bits[] = {
1287 static void print_tm_bits(unsigned long val)
1290 * This only prints something if at least one of the TM bit is set.
1291 * Inside the TM[], the output means:
1292 * E: Enabled (bit 32)
1293 * S: Suspended (bit 33)
1294 * T: Transactional (bit 34)
1296 if (val & (MSR_TM | MSR_TS_S | MSR_TS_T)) {
1298 print_bits(val, msr_tm_bits, "");
1303 static void print_tm_bits(unsigned long val) {}
1306 static void print_msr_bits(unsigned long val)
1309 print_bits(val, msr_bits, ",");
1315 #define REG "%016lx"
1316 #define REGS_PER_LINE 4
1317 #define LAST_VOLATILE 13
1320 #define REGS_PER_LINE 8
1321 #define LAST_VOLATILE 12
1324 void show_regs(struct pt_regs * regs)
1328 show_regs_print_info(KERN_DEFAULT);
1330 printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
1331 regs->nip, regs->link, regs->ctr);
1332 printk("REGS: %p TRAP: %04lx %s (%s)\n",
1333 regs, regs->trap, print_tainted(), init_utsname()->release);
1334 printk("MSR: "REG" ", regs->msr);
1335 print_msr_bits(regs->msr);
1336 printk(" CR: %08lx XER: %08lx\n", regs->ccr, regs->xer);
1338 if ((regs->trap != 0xc00) && cpu_has_feature(CPU_FTR_CFAR))
1339 printk("CFAR: "REG" ", regs->orig_gpr3);
1340 if (trap == 0x200 || trap == 0x300 || trap == 0x600)
1341 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
1342 printk("DEAR: "REG" ESR: "REG" ", regs->dar, regs->dsisr);
1344 printk("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr);
1347 printk("SOFTE: %ld ", regs->softe);
1349 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1350 if (MSR_TM_ACTIVE(regs->msr))
1351 printk("\nPACATMSCRATCH: %016llx ", get_paca()->tm_scratch);
1354 for (i = 0; i < 32; i++) {
1355 if ((i % REGS_PER_LINE) == 0)
1356 printk("\nGPR%02d: ", i);
1357 printk(REG " ", regs->gpr[i]);
1358 if (i == LAST_VOLATILE && !FULL_REGS(regs))
1362 #ifdef CONFIG_KALLSYMS
1364 * Lookup NIP late so we have the best change of getting the
1365 * above info out without failing
1367 printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip);
1368 printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link);
1370 show_stack(current, (unsigned long *) regs->gpr[1]);
1371 if (!user_mode(regs))
1372 show_instructions(regs);
1375 void flush_thread(void)
1377 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1378 flush_ptrace_hw_breakpoint(current);
1379 #else /* CONFIG_HAVE_HW_BREAKPOINT */
1380 set_debug_reg_defaults(¤t->thread);
1381 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
1385 release_thread(struct task_struct *t)
1390 * this gets called so that we can store coprocessor state into memory and
1391 * copy the current task into the new thread.
1393 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
1395 flush_all_to_thread(src);
1397 * Flush TM state out so we can copy it. __switch_to_tm() does this
1398 * flush but it removes the checkpointed state from the current CPU and
1399 * transitions the CPU out of TM mode. Hence we need to call
1400 * tm_recheckpoint_new_task() (on the same task) to restore the
1401 * checkpointed state back and the TM mode.
1403 __switch_to_tm(src);
1404 tm_recheckpoint_new_task(src);
1408 clear_task_ebb(dst);
1413 static void setup_ksp_vsid(struct task_struct *p, unsigned long sp)
1415 #ifdef CONFIG_PPC_STD_MMU_64
1416 unsigned long sp_vsid;
1417 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
1419 if (radix_enabled())
1422 if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
1423 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T)
1424 << SLB_VSID_SHIFT_1T;
1426 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M)
1428 sp_vsid |= SLB_VSID_KERNEL | llp;
1429 p->thread.ksp_vsid = sp_vsid;
1438 * Copy architecture-specific thread state
1440 int copy_thread(unsigned long clone_flags, unsigned long usp,
1441 unsigned long kthread_arg, struct task_struct *p)
1443 struct pt_regs *childregs, *kregs;
1444 extern void ret_from_fork(void);
1445 extern void ret_from_kernel_thread(void);
1447 unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
1448 struct thread_info *ti = task_thread_info(p);
1450 klp_init_thread_info(ti);
1452 /* Copy registers */
1453 sp -= sizeof(struct pt_regs);
1454 childregs = (struct pt_regs *) sp;
1455 if (unlikely(p->flags & PF_KTHREAD)) {
1457 memset(childregs, 0, sizeof(struct pt_regs));
1458 childregs->gpr[1] = sp + sizeof(struct pt_regs);
1461 childregs->gpr[14] = ppc_function_entry((void *)usp);
1463 clear_tsk_thread_flag(p, TIF_32BIT);
1464 childregs->softe = 1;
1466 childregs->gpr[15] = kthread_arg;
1467 p->thread.regs = NULL; /* no user register state */
1468 ti->flags |= _TIF_RESTOREALL;
1469 f = ret_from_kernel_thread;
1472 struct pt_regs *regs = current_pt_regs();
1473 CHECK_FULL_REGS(regs);
1476 childregs->gpr[1] = usp;
1477 p->thread.regs = childregs;
1478 childregs->gpr[3] = 0; /* Result from fork() */
1479 if (clone_flags & CLONE_SETTLS) {
1481 if (!is_32bit_task())
1482 childregs->gpr[13] = childregs->gpr[6];
1485 childregs->gpr[2] = childregs->gpr[6];
1490 childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX);
1491 sp -= STACK_FRAME_OVERHEAD;
1494 * The way this works is that at some point in the future
1495 * some task will call _switch to switch to the new task.
1496 * That will pop off the stack frame created below and start
1497 * the new task running at ret_from_fork. The new task will
1498 * do some house keeping and then return from the fork or clone
1499 * system call, using the stack frame created above.
1501 ((unsigned long *)sp)[0] = 0;
1502 sp -= sizeof(struct pt_regs);
1503 kregs = (struct pt_regs *) sp;
1504 sp -= STACK_FRAME_OVERHEAD;
1507 p->thread.ksp_limit = (unsigned long)task_stack_page(p) +
1508 _ALIGN_UP(sizeof(struct thread_info), 16);
1510 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1511 p->thread.ptrace_bps[0] = NULL;
1514 p->thread.fp_save_area = NULL;
1515 #ifdef CONFIG_ALTIVEC
1516 p->thread.vr_save_area = NULL;
1519 setup_ksp_vsid(p, sp);
1522 if (cpu_has_feature(CPU_FTR_DSCR)) {
1523 p->thread.dscr_inherit = current->thread.dscr_inherit;
1524 p->thread.dscr = mfspr(SPRN_DSCR);
1526 if (cpu_has_feature(CPU_FTR_HAS_PPR))
1527 p->thread.ppr = INIT_PPR;
1529 kregs->nip = ppc_function_entry(f);
1534 * Set up a thread for executing a new program
1536 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
1539 unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
1543 * If we exec out of a kernel thread then thread.regs will not be
1546 if (!current->thread.regs) {
1547 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
1548 current->thread.regs = regs - 1;
1551 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1553 * Clear any transactional state, we're exec()ing. The cause is
1554 * not important as there will never be a recheckpoint so it's not
1557 if (MSR_TM_SUSPENDED(mfmsr()))
1558 tm_reclaim_current(0);
1561 memset(regs->gpr, 0, sizeof(regs->gpr));
1569 * We have just cleared all the nonvolatile GPRs, so make
1570 * FULL_REGS(regs) return true. This is necessary to allow
1571 * ptrace to examine the thread immediately after exec.
1578 regs->msr = MSR_USER;
1580 if (!is_32bit_task()) {
1581 unsigned long entry;
1583 if (is_elf2_task()) {
1584 /* Look ma, no function descriptors! */
1589 * The latest iteration of the ABI requires that when
1590 * calling a function (at its global entry point),
1591 * the caller must ensure r12 holds the entry point
1592 * address (so that the function can quickly
1593 * establish addressability).
1595 regs->gpr[12] = start;
1596 /* Make sure that's restored on entry to userspace. */
1597 set_thread_flag(TIF_RESTOREALL);
1601 /* start is a relocated pointer to the function
1602 * descriptor for the elf _start routine. The first
1603 * entry in the function descriptor is the entry
1604 * address of _start and the second entry is the TOC
1605 * value we need to use.
1607 __get_user(entry, (unsigned long __user *)start);
1608 __get_user(toc, (unsigned long __user *)start+1);
1610 /* Check whether the e_entry function descriptor entries
1611 * need to be relocated before we can use them.
1613 if (load_addr != 0) {
1620 regs->msr = MSR_USER64;
1624 regs->msr = MSR_USER32;
1628 current->thread.used_vsr = 0;
1630 memset(¤t->thread.fp_state, 0, sizeof(current->thread.fp_state));
1631 current->thread.fp_save_area = NULL;
1632 #ifdef CONFIG_ALTIVEC
1633 memset(¤t->thread.vr_state, 0, sizeof(current->thread.vr_state));
1634 current->thread.vr_state.vscr.u[3] = 0x00010000; /* Java mode disabled */
1635 current->thread.vr_save_area = NULL;
1636 current->thread.vrsave = 0;
1637 current->thread.used_vr = 0;
1638 #endif /* CONFIG_ALTIVEC */
1640 memset(current->thread.evr, 0, sizeof(current->thread.evr));
1641 current->thread.acc = 0;
1642 current->thread.spefscr = 0;
1643 current->thread.used_spe = 0;
1644 #endif /* CONFIG_SPE */
1645 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1646 if (cpu_has_feature(CPU_FTR_TM))
1647 regs->msr |= MSR_TM;
1648 current->thread.tm_tfhar = 0;
1649 current->thread.tm_texasr = 0;
1650 current->thread.tm_tfiar = 0;
1651 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
1653 EXPORT_SYMBOL(start_thread);
1655 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
1656 | PR_FP_EXC_RES | PR_FP_EXC_INV)
1658 int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
1660 struct pt_regs *regs = tsk->thread.regs;
1662 /* This is a bit hairy. If we are an SPE enabled processor
1663 * (have embedded fp) we store the IEEE exception enable flags in
1664 * fpexc_mode. fpexc_mode is also used for setting FP exception
1665 * mode (asyn, precise, disabled) for 'Classic' FP. */
1666 if (val & PR_FP_EXC_SW_ENABLE) {
1668 if (cpu_has_feature(CPU_FTR_SPE)) {
1670 * When the sticky exception bits are set
1671 * directly by userspace, it must call prctl
1672 * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
1673 * in the existing prctl settings) or
1674 * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
1675 * the bits being set). <fenv.h> functions
1676 * saving and restoring the whole
1677 * floating-point environment need to do so
1678 * anyway to restore the prctl settings from
1679 * the saved environment.
1681 tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
1682 tsk->thread.fpexc_mode = val &
1683 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
1693 /* on a CONFIG_SPE this does not hurt us. The bits that
1694 * __pack_fe01 use do not overlap with bits used for
1695 * PR_FP_EXC_SW_ENABLE. Additionally, the MSR[FE0,FE1] bits
1696 * on CONFIG_SPE implementations are reserved so writing to
1697 * them does not change anything */
1698 if (val > PR_FP_EXC_PRECISE)
1700 tsk->thread.fpexc_mode = __pack_fe01(val);
1701 if (regs != NULL && (regs->msr & MSR_FP) != 0)
1702 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
1703 | tsk->thread.fpexc_mode;
1707 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
1711 if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
1713 if (cpu_has_feature(CPU_FTR_SPE)) {
1715 * When the sticky exception bits are set
1716 * directly by userspace, it must call prctl
1717 * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
1718 * in the existing prctl settings) or
1719 * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
1720 * the bits being set). <fenv.h> functions
1721 * saving and restoring the whole
1722 * floating-point environment need to do so
1723 * anyway to restore the prctl settings from
1724 * the saved environment.
1726 tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
1727 val = tsk->thread.fpexc_mode;
1734 val = __unpack_fe01(tsk->thread.fpexc_mode);
1735 return put_user(val, (unsigned int __user *) adr);
1738 int set_endian(struct task_struct *tsk, unsigned int val)
1740 struct pt_regs *regs = tsk->thread.regs;
1742 if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) ||
1743 (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE)))
1749 if (val == PR_ENDIAN_BIG)
1750 regs->msr &= ~MSR_LE;
1751 else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
1752 regs->msr |= MSR_LE;
1759 int get_endian(struct task_struct *tsk, unsigned long adr)
1761 struct pt_regs *regs = tsk->thread.regs;
1764 if (!cpu_has_feature(CPU_FTR_PPC_LE) &&
1765 !cpu_has_feature(CPU_FTR_REAL_LE))
1771 if (regs->msr & MSR_LE) {
1772 if (cpu_has_feature(CPU_FTR_REAL_LE))
1773 val = PR_ENDIAN_LITTLE;
1775 val = PR_ENDIAN_PPC_LITTLE;
1777 val = PR_ENDIAN_BIG;
1779 return put_user(val, (unsigned int __user *)adr);
1782 int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
1784 tsk->thread.align_ctl = val;
1788 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
1790 return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
1793 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
1794 unsigned long nbytes)
1796 unsigned long stack_page;
1797 unsigned long cpu = task_cpu(p);
1800 * Avoid crashing if the stack has overflowed and corrupted
1801 * task_cpu(p), which is in the thread_info struct.
1803 if (cpu < NR_CPUS && cpu_possible(cpu)) {
1804 stack_page = (unsigned long) hardirq_ctx[cpu];
1805 if (sp >= stack_page + sizeof(struct thread_struct)
1806 && sp <= stack_page + THREAD_SIZE - nbytes)
1809 stack_page = (unsigned long) softirq_ctx[cpu];
1810 if (sp >= stack_page + sizeof(struct thread_struct)
1811 && sp <= stack_page + THREAD_SIZE - nbytes)
1817 int validate_sp(unsigned long sp, struct task_struct *p,
1818 unsigned long nbytes)
1820 unsigned long stack_page = (unsigned long)task_stack_page(p);
1822 if (sp >= stack_page + sizeof(struct thread_struct)
1823 && sp <= stack_page + THREAD_SIZE - nbytes)
1826 return valid_irq_stack(sp, p, nbytes);
1829 EXPORT_SYMBOL(validate_sp);
1831 unsigned long get_wchan(struct task_struct *p)
1833 unsigned long ip, sp;
1836 if (!p || p == current || p->state == TASK_RUNNING)
1840 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
1844 sp = *(unsigned long *)sp;
1845 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
1848 ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE];
1849 if (!in_sched_functions(ip))
1852 } while (count++ < 16);
1856 static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH;
1858 void show_stack(struct task_struct *tsk, unsigned long *stack)
1860 unsigned long sp, ip, lr, newsp;
1863 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1864 int curr_frame = current->curr_ret_stack;
1865 extern void return_to_handler(void);
1866 unsigned long rth = (unsigned long)return_to_handler;
1869 sp = (unsigned long) stack;
1874 sp = current_stack_pointer();
1876 sp = tsk->thread.ksp;
1880 printk("Call Trace:\n");
1882 if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
1885 stack = (unsigned long *) sp;
1887 ip = stack[STACK_FRAME_LR_SAVE];
1888 if (!firstframe || ip != lr) {
1889 printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip);
1890 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1891 if ((ip == rth) && curr_frame >= 0) {
1893 (void *)current->ret_stack[curr_frame].ret);
1898 printk(" (unreliable)");
1904 * See if this is an exception frame.
1905 * We look for the "regshere" marker in the current frame.
1907 if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE)
1908 && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
1909 struct pt_regs *regs = (struct pt_regs *)
1910 (sp + STACK_FRAME_OVERHEAD);
1912 printk("--- interrupt: %lx at %pS\n LR = %pS\n",
1913 regs->trap, (void *)regs->nip, (void *)lr);
1918 } while (count++ < kstack_depth_to_print);
1922 /* Called with hard IRQs off */
1923 void notrace __ppc64_runlatch_on(void)
1925 struct thread_info *ti = current_thread_info();
1928 ctrl = mfspr(SPRN_CTRLF);
1929 ctrl |= CTRL_RUNLATCH;
1930 mtspr(SPRN_CTRLT, ctrl);
1932 ti->local_flags |= _TLF_RUNLATCH;
1935 /* Called with hard IRQs off */
1936 void notrace __ppc64_runlatch_off(void)
1938 struct thread_info *ti = current_thread_info();
1941 ti->local_flags &= ~_TLF_RUNLATCH;
1943 ctrl = mfspr(SPRN_CTRLF);
1944 ctrl &= ~CTRL_RUNLATCH;
1945 mtspr(SPRN_CTRLT, ctrl);
1947 #endif /* CONFIG_PPC64 */
1949 unsigned long arch_align_stack(unsigned long sp)
1951 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
1952 sp -= get_random_int() & ~PAGE_MASK;
1956 static inline unsigned long brk_rnd(void)
1958 unsigned long rnd = 0;
1960 /* 8MB for 32bit, 1GB for 64bit */
1961 if (is_32bit_task())
1962 rnd = (get_random_long() % (1UL<<(23-PAGE_SHIFT)));
1964 rnd = (get_random_long() % (1UL<<(30-PAGE_SHIFT)));
1966 return rnd << PAGE_SHIFT;
1969 unsigned long arch_randomize_brk(struct mm_struct *mm)
1971 unsigned long base = mm->brk;
1974 #ifdef CONFIG_PPC_STD_MMU_64
1976 * If we are using 1TB segments and we are allowed to randomise
1977 * the heap, we can put it above 1TB so it is backed by a 1TB
1978 * segment. Otherwise the heap will be in the bottom 1TB
1979 * which always uses 256MB segments and this may result in a
1980 * performance penalty. We don't need to worry about radix. For
1981 * radix, mmu_highuser_ssize remains unchanged from 256MB.
1983 if (!is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T))
1984 base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T);
1987 ret = PAGE_ALIGN(base + brk_rnd());