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/sched/debug.h>
  20#include <linux/sched/task.h>
  21#include <linux/sched/task_stack.h>
  22#include <linux/kernel.h>
  23#include <linux/mm.h>
  24#include <linux/smp.h>
  25#include <linux/stddef.h>
  26#include <linux/unistd.h>
  27#include <linux/ptrace.h>
  28#include <linux/slab.h>
  29#include <linux/user.h>
  30#include <linux/elf.h>
  31#include <linux/prctl.h>
  32#include <linux/init_task.h>
  33#include <linux/export.h>
  34#include <linux/kallsyms.h>
  35#include <linux/mqueue.h>
  36#include <linux/hardirq.h>
  37#include <linux/utsname.h>
  38#include <linux/ftrace.h>
  39#include <linux/kernel_stat.h>
  40#include <linux/personality.h>
  41#include <linux/random.h>
  42#include <linux/hw_breakpoint.h>
  43#include <linux/uaccess.h>
  44#include <linux/elf-randomize.h>
  45#include <linux/pkeys.h>
  46
  47#include <asm/pgtable.h>
  48#include <asm/io.h>
  49#include <asm/processor.h>
  50#include <asm/mmu.h>
  51#include <asm/prom.h>
  52#include <asm/machdep.h>
  53#include <asm/time.h>
  54#include <asm/runlatch.h>
  55#include <asm/syscalls.h>
  56#include <asm/switch_to.h>
  57#include <asm/tm.h>
  58#include <asm/debug.h>
  59#ifdef CONFIG_PPC64
  60#include <asm/firmware.h>
  61#include <asm/hw_irq.h>
  62#endif
  63#include <asm/code-patching.h>
  64#include <asm/exec.h>
  65#include <asm/livepatch.h>
  66#include <asm/cpu_has_feature.h>
  67#include <asm/asm-prototypes.h>
  68
  69#include <linux/kprobes.h>
  70#include <linux/kdebug.h>
  71
  72/* Transactional Memory debug */
  73#ifdef TM_DEBUG_SW
  74#define TM_DEBUG(x...) printk(KERN_INFO x)
  75#else
  76#define TM_DEBUG(x...) do { } while(0)
  77#endif
  78
  79extern unsigned long _get_SP(void);
  80
  81#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  82/*
  83 * Are we running in "Suspend disabled" mode? If so we have to block any
  84 * sigreturn that would get us into suspended state, and we also warn in some
  85 * other paths that we should never reach with suspend disabled.
  86 */
  87bool tm_suspend_disabled __ro_after_init = false;
  88
  89static void check_if_tm_restore_required(struct task_struct *tsk)
  90{
  91	/*
  92	 * If we are saving the current thread's registers, and the
  93	 * thread is in a transactional state, set the TIF_RESTORE_TM
  94	 * bit so that we know to restore the registers before
  95	 * returning to userspace.
  96	 */
  97	if (tsk == current && tsk->thread.regs &&
  98	    MSR_TM_ACTIVE(tsk->thread.regs->msr) &&
  99	    !test_thread_flag(TIF_RESTORE_TM)) {
 100		tsk->thread.ckpt_regs.msr = tsk->thread.regs->msr;
 101		set_thread_flag(TIF_RESTORE_TM);
 102	}
 103}
 104
 105static inline bool msr_tm_active(unsigned long msr)
 106{
 107	return MSR_TM_ACTIVE(msr);
 108}
 109
 110static bool tm_active_with_fp(struct task_struct *tsk)
 111{
 112	return msr_tm_active(tsk->thread.regs->msr) &&
 113		(tsk->thread.ckpt_regs.msr & MSR_FP);
 114}
 115
 116static bool tm_active_with_altivec(struct task_struct *tsk)
 117{
 118	return msr_tm_active(tsk->thread.regs->msr) &&
 119		(tsk->thread.ckpt_regs.msr & MSR_VEC);
 120}
 121#else
 122static inline bool msr_tm_active(unsigned long msr) { return false; }
 123static inline void check_if_tm_restore_required(struct task_struct *tsk) { }
 124static inline bool tm_active_with_fp(struct task_struct *tsk) { return false; }
 125static inline bool tm_active_with_altivec(struct task_struct *tsk) { return false; }
 126#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 127
 128bool strict_msr_control;
 129EXPORT_SYMBOL(strict_msr_control);
 130
 131static int __init enable_strict_msr_control(char *str)
 132{
 133	strict_msr_control = true;
 134	pr_info("Enabling strict facility control\n");
 135
 136	return 0;
 137}
 138early_param("ppc_strict_facility_enable", enable_strict_msr_control);
 139
 140unsigned long msr_check_and_set(unsigned long bits)
 141{
 142	unsigned long oldmsr = mfmsr();
 143	unsigned long newmsr;
 144
 145	newmsr = oldmsr | bits;
 146
 147#ifdef CONFIG_VSX
 148	if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
 149		newmsr |= MSR_VSX;
 150#endif
 151
 152	if (oldmsr != newmsr)
 153		mtmsr_isync(newmsr);
 154
 155	return newmsr;
 156}
 157
 158void __msr_check_and_clear(unsigned long bits)
 159{
 160	unsigned long oldmsr = mfmsr();
 161	unsigned long newmsr;
 162
 163	newmsr = oldmsr & ~bits;
 164
 165#ifdef CONFIG_VSX
 166	if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
 167		newmsr &= ~MSR_VSX;
 168#endif
 169
 170	if (oldmsr != newmsr)
 171		mtmsr_isync(newmsr);
 172}
 173EXPORT_SYMBOL(__msr_check_and_clear);
 174
 175#ifdef CONFIG_PPC_FPU
 176static void __giveup_fpu(struct task_struct *tsk)
 177{
 178	unsigned long msr;
 179
 180	save_fpu(tsk);
 181	msr = tsk->thread.regs->msr;
 182	msr &= ~MSR_FP;
 183#ifdef CONFIG_VSX
 184	if (cpu_has_feature(CPU_FTR_VSX))
 185		msr &= ~MSR_VSX;
 186#endif
 187	tsk->thread.regs->msr = msr;
 188}
 189
 190void giveup_fpu(struct task_struct *tsk)
 191{
 192	check_if_tm_restore_required(tsk);
 193
 194	msr_check_and_set(MSR_FP);
 195	__giveup_fpu(tsk);
 196	msr_check_and_clear(MSR_FP);
 197}
 198EXPORT_SYMBOL(giveup_fpu);
 199
 200/*
 201 * Make sure the floating-point register state in the
 202 * the thread_struct is up to date for task tsk.
 203 */
 204void flush_fp_to_thread(struct task_struct *tsk)
 205{
 206	if (tsk->thread.regs) {
 207		/*
 208		 * We need to disable preemption here because if we didn't,
 209		 * another process could get scheduled after the regs->msr
 210		 * test but before we have finished saving the FP registers
 211		 * to the thread_struct.  That process could take over the
 212		 * FPU, and then when we get scheduled again we would store
 213		 * bogus values for the remaining FP registers.
 214		 */
 215		preempt_disable();
 216		if (tsk->thread.regs->msr & MSR_FP) {
 217			/*
 218			 * This should only ever be called for current or
 219			 * for a stopped child process.  Since we save away
 220			 * the FP register state on context switch,
 221			 * there is something wrong if a stopped child appears
 222			 * to still have its FP state in the CPU registers.
 223			 */
 224			BUG_ON(tsk != current);
 225			giveup_fpu(tsk);
 226		}
 227		preempt_enable();
 228	}
 229}
 230EXPORT_SYMBOL_GPL(flush_fp_to_thread);
 231
 232void enable_kernel_fp(void)
 233{
 234	unsigned long cpumsr;
 235
 236	WARN_ON(preemptible());
 237
 238	cpumsr = msr_check_and_set(MSR_FP);
 239
 240	if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) {
 241		check_if_tm_restore_required(current);
 242		/*
 243		 * If a thread has already been reclaimed then the
 244		 * checkpointed registers are on the CPU but have definitely
 245		 * been saved by the reclaim code. Don't need to and *cannot*
 246		 * giveup as this would save  to the 'live' structure not the
 247		 * checkpointed structure.
 248		 */
 249		if(!msr_tm_active(cpumsr) && msr_tm_active(current->thread.regs->msr))
 250			return;
 251		__giveup_fpu(current);
 252	}
 253}
 254EXPORT_SYMBOL(enable_kernel_fp);
 255
 256static int restore_fp(struct task_struct *tsk)
 257{
 258	if (tsk->thread.load_fp || tm_active_with_fp(tsk)) {
 259		load_fp_state(&current->thread.fp_state);
 260		current->thread.load_fp++;
 261		return 1;
 262	}
 263	return 0;
 264}
 265#else
 266static int restore_fp(struct task_struct *tsk) { return 0; }
 267#endif /* CONFIG_PPC_FPU */
 268
 269#ifdef CONFIG_ALTIVEC
 270#define loadvec(thr) ((thr).load_vec)
 271
 272static void __giveup_altivec(struct task_struct *tsk)
 273{
 274	unsigned long msr;
 275
 276	save_altivec(tsk);
 277	msr = tsk->thread.regs->msr;
 278	msr &= ~MSR_VEC;
 279#ifdef CONFIG_VSX
 280	if (cpu_has_feature(CPU_FTR_VSX))
 281		msr &= ~MSR_VSX;
 282#endif
 283	tsk->thread.regs->msr = msr;
 284}
 285
 286void giveup_altivec(struct task_struct *tsk)
 287{
 288	check_if_tm_restore_required(tsk);
 289
 290	msr_check_and_set(MSR_VEC);
 291	__giveup_altivec(tsk);
 292	msr_check_and_clear(MSR_VEC);
 293}
 294EXPORT_SYMBOL(giveup_altivec);
 295
 296void enable_kernel_altivec(void)
 297{
 298	unsigned long cpumsr;
 299
 300	WARN_ON(preemptible());
 301
 302	cpumsr = msr_check_and_set(MSR_VEC);
 303
 304	if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) {
 305		check_if_tm_restore_required(current);
 306		/*
 307		 * If a thread has already been reclaimed then the
 308		 * checkpointed registers are on the CPU but have definitely
 309		 * been saved by the reclaim code. Don't need to and *cannot*
 310		 * giveup as this would save  to the 'live' structure not the
 311		 * checkpointed structure.
 312		 */
 313		if(!msr_tm_active(cpumsr) && msr_tm_active(current->thread.regs->msr))
 314			return;
 315		__giveup_altivec(current);
 316	}
 317}
 318EXPORT_SYMBOL(enable_kernel_altivec);
 319
 320/*
 321 * Make sure the VMX/Altivec register state in the
 322 * the thread_struct is up to date for task tsk.
 323 */
 324void flush_altivec_to_thread(struct task_struct *tsk)
 325{
 326	if (tsk->thread.regs) {
 327		preempt_disable();
 328		if (tsk->thread.regs->msr & MSR_VEC) {
 329			BUG_ON(tsk != current);
 330			giveup_altivec(tsk);
 331		}
 332		preempt_enable();
 333	}
 334}
 335EXPORT_SYMBOL_GPL(flush_altivec_to_thread);
 336
 337static int restore_altivec(struct task_struct *tsk)
 338{
 339	if (cpu_has_feature(CPU_FTR_ALTIVEC) &&
 340		(tsk->thread.load_vec || tm_active_with_altivec(tsk))) {
 341		load_vr_state(&tsk->thread.vr_state);
 342		tsk->thread.used_vr = 1;
 343		tsk->thread.load_vec++;
 344
 345		return 1;
 346	}
 347	return 0;
 348}
 349#else
 350#define loadvec(thr) 0
 351static inline int restore_altivec(struct task_struct *tsk) { return 0; }
 352#endif /* CONFIG_ALTIVEC */
 353
 354#ifdef CONFIG_VSX
 355static void __giveup_vsx(struct task_struct *tsk)
 356{
 357	unsigned long msr = tsk->thread.regs->msr;
 358
 359	/*
 360	 * We should never be ssetting MSR_VSX without also setting
 361	 * MSR_FP and MSR_VEC
 362	 */
 363	WARN_ON((msr & MSR_VSX) && !((msr & MSR_FP) && (msr & MSR_VEC)));
 364
 365	/* __giveup_fpu will clear MSR_VSX */
 366	if (msr & MSR_FP)
 367		__giveup_fpu(tsk);
 368	if (msr & MSR_VEC)
 369		__giveup_altivec(tsk);
 
 370}
 371
 372static void giveup_vsx(struct task_struct *tsk)
 373{
 374	check_if_tm_restore_required(tsk);
 375
 376	msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
 377	__giveup_vsx(tsk);
 378	msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX);
 379}
 380
 381void enable_kernel_vsx(void)
 382{
 383	unsigned long cpumsr;
 
 
 
 
 384
 
 
 385	WARN_ON(preemptible());
 386
 387	cpumsr = msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
 388
 389	if (current->thread.regs &&
 390	    (current->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP))) {
 391		check_if_tm_restore_required(current);
 392		/*
 393		 * If a thread has already been reclaimed then the
 394		 * checkpointed registers are on the CPU but have definitely
 395		 * been saved by the reclaim code. Don't need to and *cannot*
 396		 * giveup as this would save  to the 'live' structure not the
 397		 * checkpointed structure.
 398		 */
 399		if(!msr_tm_active(cpumsr) && msr_tm_active(current->thread.regs->msr))
 400			return;
 401		__giveup_vsx(current);
 402	}
 403}
 404EXPORT_SYMBOL(enable_kernel_vsx);
 405
 406void flush_vsx_to_thread(struct task_struct *tsk)
 407{
 408	if (tsk->thread.regs) {
 409		preempt_disable();
 410		if (tsk->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP)) {
 411			BUG_ON(tsk != current);
 412			giveup_vsx(tsk);
 413		}
 414		preempt_enable();
 415	}
 416}
 417EXPORT_SYMBOL_GPL(flush_vsx_to_thread);
 418
 419static int restore_vsx(struct task_struct *tsk)
 420{
 421	if (cpu_has_feature(CPU_FTR_VSX)) {
 422		tsk->thread.used_vsr = 1;
 423		return 1;
 424	}
 425
 426	return 0;
 427}
 428#else
 429static inline int restore_vsx(struct task_struct *tsk) { return 0; }
 
 430#endif /* CONFIG_VSX */
 431
 432#ifdef CONFIG_SPE
 433void giveup_spe(struct task_struct *tsk)
 434{
 435	check_if_tm_restore_required(tsk);
 436
 437	msr_check_and_set(MSR_SPE);
 438	__giveup_spe(tsk);
 439	msr_check_and_clear(MSR_SPE);
 440}
 441EXPORT_SYMBOL(giveup_spe);
 442
 443void enable_kernel_spe(void)
 444{
 445	WARN_ON(preemptible());
 446
 447	msr_check_and_set(MSR_SPE);
 448
 449	if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) {
 450		check_if_tm_restore_required(current);
 451		__giveup_spe(current);
 452	}
 453}
 454EXPORT_SYMBOL(enable_kernel_spe);
 455
 456void flush_spe_to_thread(struct task_struct *tsk)
 457{
 458	if (tsk->thread.regs) {
 459		preempt_disable();
 460		if (tsk->thread.regs->msr & MSR_SPE) {
 461			BUG_ON(tsk != current);
 462			tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
 463			giveup_spe(tsk);
 464		}
 465		preempt_enable();
 466	}
 467}
 468#endif /* CONFIG_SPE */
 469
 470static unsigned long msr_all_available;
 471
 472static int __init init_msr_all_available(void)
 473{
 474#ifdef CONFIG_PPC_FPU
 475	msr_all_available |= MSR_FP;
 476#endif
 477#ifdef CONFIG_ALTIVEC
 478	if (cpu_has_feature(CPU_FTR_ALTIVEC))
 479		msr_all_available |= MSR_VEC;
 480#endif
 481#ifdef CONFIG_VSX
 482	if (cpu_has_feature(CPU_FTR_VSX))
 483		msr_all_available |= MSR_VSX;
 484#endif
 485#ifdef CONFIG_SPE
 486	if (cpu_has_feature(CPU_FTR_SPE))
 487		msr_all_available |= MSR_SPE;
 488#endif
 489
 490	return 0;
 491}
 492early_initcall(init_msr_all_available);
 493
 494void giveup_all(struct task_struct *tsk)
 495{
 496	unsigned long usermsr;
 497
 498	if (!tsk->thread.regs)
 499		return;
 500
 501	usermsr = tsk->thread.regs->msr;
 502
 503	if ((usermsr & msr_all_available) == 0)
 504		return;
 505
 506	msr_check_and_set(msr_all_available);
 507	check_if_tm_restore_required(tsk);
 508
 509	WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC)));
 510
 511#ifdef CONFIG_PPC_FPU
 512	if (usermsr & MSR_FP)
 513		__giveup_fpu(tsk);
 514#endif
 515#ifdef CONFIG_ALTIVEC
 516	if (usermsr & MSR_VEC)
 517		__giveup_altivec(tsk);
 518#endif
 
 
 
 
 519#ifdef CONFIG_SPE
 520	if (usermsr & MSR_SPE)
 521		__giveup_spe(tsk);
 522#endif
 523
 524	msr_check_and_clear(msr_all_available);
 525}
 526EXPORT_SYMBOL(giveup_all);
 527
 528void restore_math(struct pt_regs *regs)
 529{
 530	unsigned long msr;
 531
 532	if (!msr_tm_active(regs->msr) &&
 533		!current->thread.load_fp && !loadvec(current->thread))
 534		return;
 535
 536	msr = regs->msr;
 537	msr_check_and_set(msr_all_available);
 538
 539	/*
 540	 * Only reload if the bit is not set in the user MSR, the bit BEING set
 541	 * indicates that the registers are hot
 542	 */
 543	if ((!(msr & MSR_FP)) && restore_fp(current))
 544		msr |= MSR_FP | current->thread.fpexc_mode;
 545
 546	if ((!(msr & MSR_VEC)) && restore_altivec(current))
 547		msr |= MSR_VEC;
 548
 549	if ((msr & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC) &&
 550			restore_vsx(current)) {
 551		msr |= MSR_VSX;
 552	}
 553
 554	msr_check_and_clear(msr_all_available);
 555
 556	regs->msr = msr;
 557}
 558
 559static void save_all(struct task_struct *tsk)
 560{
 561	unsigned long usermsr;
 562
 563	if (!tsk->thread.regs)
 564		return;
 565
 566	usermsr = tsk->thread.regs->msr;
 567
 568	if ((usermsr & msr_all_available) == 0)
 569		return;
 570
 571	msr_check_and_set(msr_all_available);
 572
 573	WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC)));
 574
 575	if (usermsr & MSR_FP)
 576		save_fpu(tsk);
 
 
 
 
 
 577
 578	if (usermsr & MSR_VEC)
 579		save_altivec(tsk);
 
 580
 581	if (usermsr & MSR_SPE)
 582		__giveup_spe(tsk);
 583
 584	msr_check_and_clear(msr_all_available);
 585}
 586
 587void flush_all_to_thread(struct task_struct *tsk)
 588{
 589	if (tsk->thread.regs) {
 590		preempt_disable();
 591		BUG_ON(tsk != current);
 592		save_all(tsk);
 593
 594#ifdef CONFIG_SPE
 595		if (tsk->thread.regs->msr & MSR_SPE)
 596			tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
 597#endif
 598
 599		preempt_enable();
 600	}
 601}
 602EXPORT_SYMBOL(flush_all_to_thread);
 603
 604#ifdef CONFIG_PPC_ADV_DEBUG_REGS
 605void do_send_trap(struct pt_regs *regs, unsigned long address,
 606		  unsigned long error_code, int breakpt)
 607{
 608	current->thread.trap_nr = TRAP_HWBKPT;
 
 
 609	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
 610			11, SIGSEGV) == NOTIFY_STOP)
 611		return;
 612
 613	/* Deliver the signal to userspace */
 614	force_sig_ptrace_errno_trap(breakpt, /* breakpoint or watchpoint id */
 615				    (void __user *)address);
 
 
 
 616}
 617#else	/* !CONFIG_PPC_ADV_DEBUG_REGS */
 618void do_break (struct pt_regs *regs, unsigned long address,
 619		    unsigned long error_code)
 620{
 621	siginfo_t info;
 622
 623	current->thread.trap_nr = TRAP_HWBKPT;
 624	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
 625			11, SIGSEGV) == NOTIFY_STOP)
 626		return;
 627
 628	if (debugger_break_match(regs))
 629		return;
 630
 631	/* Clear the breakpoint */
 632	hw_breakpoint_disable();
 633
 634	/* Deliver the signal to userspace */
 635	info.si_signo = SIGTRAP;
 636	info.si_errno = 0;
 637	info.si_code = TRAP_HWBKPT;
 638	info.si_addr = (void __user *)address;
 639	force_sig_info(SIGTRAP, &info, current);
 640}
 641#endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
 642
 643static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk);
 644
 645#ifdef CONFIG_PPC_ADV_DEBUG_REGS
 646/*
 647 * Set the debug registers back to their default "safe" values.
 648 */
 649static void set_debug_reg_defaults(struct thread_struct *thread)
 650{
 651	thread->debug.iac1 = thread->debug.iac2 = 0;
 652#if CONFIG_PPC_ADV_DEBUG_IACS > 2
 653	thread->debug.iac3 = thread->debug.iac4 = 0;
 654#endif
 655	thread->debug.dac1 = thread->debug.dac2 = 0;
 656#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
 657	thread->debug.dvc1 = thread->debug.dvc2 = 0;
 658#endif
 659	thread->debug.dbcr0 = 0;
 660#ifdef CONFIG_BOOKE
 661	/*
 662	 * Force User/Supervisor bits to b11 (user-only MSR[PR]=1)
 663	 */
 664	thread->debug.dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US |
 665			DBCR1_IAC3US | DBCR1_IAC4US;
 666	/*
 667	 * Force Data Address Compare User/Supervisor bits to be User-only
 668	 * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0.
 669	 */
 670	thread->debug.dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US;
 671#else
 672	thread->debug.dbcr1 = 0;
 673#endif
 674}
 675
 676static void prime_debug_regs(struct debug_reg *debug)
 677{
 678	/*
 679	 * We could have inherited MSR_DE from userspace, since
 680	 * it doesn't get cleared on exception entry.  Make sure
 681	 * MSR_DE is clear before we enable any debug events.
 682	 */
 683	mtmsr(mfmsr() & ~MSR_DE);
 684
 685	mtspr(SPRN_IAC1, debug->iac1);
 686	mtspr(SPRN_IAC2, debug->iac2);
 687#if CONFIG_PPC_ADV_DEBUG_IACS > 2
 688	mtspr(SPRN_IAC3, debug->iac3);
 689	mtspr(SPRN_IAC4, debug->iac4);
 690#endif
 691	mtspr(SPRN_DAC1, debug->dac1);
 692	mtspr(SPRN_DAC2, debug->dac2);
 693#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
 694	mtspr(SPRN_DVC1, debug->dvc1);
 695	mtspr(SPRN_DVC2, debug->dvc2);
 696#endif
 697	mtspr(SPRN_DBCR0, debug->dbcr0);
 698	mtspr(SPRN_DBCR1, debug->dbcr1);
 699#ifdef CONFIG_BOOKE
 700	mtspr(SPRN_DBCR2, debug->dbcr2);
 701#endif
 702}
 703/*
 704 * Unless neither the old or new thread are making use of the
 705 * debug registers, set the debug registers from the values
 706 * stored in the new thread.
 707 */
 708void switch_booke_debug_regs(struct debug_reg *new_debug)
 709{
 710	if ((current->thread.debug.dbcr0 & DBCR0_IDM)
 711		|| (new_debug->dbcr0 & DBCR0_IDM))
 712			prime_debug_regs(new_debug);
 713}
 714EXPORT_SYMBOL_GPL(switch_booke_debug_regs);
 715#else	/* !CONFIG_PPC_ADV_DEBUG_REGS */
 716#ifndef CONFIG_HAVE_HW_BREAKPOINT
 717static void set_debug_reg_defaults(struct thread_struct *thread)
 718{
 719	thread->hw_brk.address = 0;
 720	thread->hw_brk.type = 0;
 721	if (ppc_breakpoint_available())
 722		set_breakpoint(&thread->hw_brk);
 723}
 724#endif /* !CONFIG_HAVE_HW_BREAKPOINT */
 725#endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
 726
 727#ifdef CONFIG_PPC_ADV_DEBUG_REGS
 728static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
 729{
 730	mtspr(SPRN_DAC1, dabr);
 731#ifdef CONFIG_PPC_47x
 732	isync();
 733#endif
 734	return 0;
 735}
 736#elif defined(CONFIG_PPC_BOOK3S)
 737static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
 738{
 739	mtspr(SPRN_DABR, dabr);
 740	if (cpu_has_feature(CPU_FTR_DABRX))
 741		mtspr(SPRN_DABRX, dabrx);
 742	return 0;
 743}
 744#elif defined(CONFIG_PPC_8xx)
 745static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
 746{
 747	unsigned long addr = dabr & ~HW_BRK_TYPE_DABR;
 748	unsigned long lctrl1 = 0x90000000; /* compare type: equal on E & F */
 749	unsigned long lctrl2 = 0x8e000002; /* watchpoint 1 on cmp E | F */
 750
 751	if ((dabr & HW_BRK_TYPE_RDWR) == HW_BRK_TYPE_READ)
 752		lctrl1 |= 0xa0000;
 753	else if ((dabr & HW_BRK_TYPE_RDWR) == HW_BRK_TYPE_WRITE)
 754		lctrl1 |= 0xf0000;
 755	else if ((dabr & HW_BRK_TYPE_RDWR) == 0)
 756		lctrl2 = 0;
 757
 758	mtspr(SPRN_LCTRL2, 0);
 759	mtspr(SPRN_CMPE, addr);
 760	mtspr(SPRN_CMPF, addr + 4);
 761	mtspr(SPRN_LCTRL1, lctrl1);
 762	mtspr(SPRN_LCTRL2, lctrl2);
 763
 764	return 0;
 765}
 766#else
 767static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
 768{
 769	return -EINVAL;
 770}
 771#endif
 772
 773static inline int set_dabr(struct arch_hw_breakpoint *brk)
 774{
 775	unsigned long dabr, dabrx;
 776
 777	dabr = brk->address | (brk->type & HW_BRK_TYPE_DABR);
 778	dabrx = ((brk->type >> 3) & 0x7);
 779
 780	if (ppc_md.set_dabr)
 781		return ppc_md.set_dabr(dabr, dabrx);
 782
 783	return __set_dabr(dabr, dabrx);
 784}
 785
 786static inline int set_dawr(struct arch_hw_breakpoint *brk)
 787{
 788	unsigned long dawr, dawrx, mrd;
 789
 790	dawr = brk->address;
 791
 792	dawrx  = (brk->type & (HW_BRK_TYPE_READ | HW_BRK_TYPE_WRITE)) \
 793		                   << (63 - 58); //* read/write bits */
 794	dawrx |= ((brk->type & (HW_BRK_TYPE_TRANSLATE)) >> 2) \
 795		                   << (63 - 59); //* translate */
 796	dawrx |= (brk->type & (HW_BRK_TYPE_PRIV_ALL)) \
 797		                   >> 3; //* PRIM bits */
 798	/* dawr length is stored in field MDR bits 48:53.  Matches range in
 799	   doublewords (64 bits) baised by -1 eg. 0b000000=1DW and
 800	   0b111111=64DW.
 801	   brk->len is in bytes.
 802	   This aligns up to double word size, shifts and does the bias.
 803	*/
 804	mrd = ((brk->len + 7) >> 3) - 1;
 805	dawrx |= (mrd & 0x3f) << (63 - 53);
 806
 807	if (ppc_md.set_dawr)
 808		return ppc_md.set_dawr(dawr, dawrx);
 809	mtspr(SPRN_DAWR, dawr);
 810	mtspr(SPRN_DAWRX, dawrx);
 811	return 0;
 812}
 813
 814void __set_breakpoint(struct arch_hw_breakpoint *brk)
 815{
 816	memcpy(this_cpu_ptr(&current_brk), brk, sizeof(*brk));
 817
 818	if (cpu_has_feature(CPU_FTR_DAWR))
 819		// Power8 or later
 820		set_dawr(brk);
 821	else if (!cpu_has_feature(CPU_FTR_ARCH_207S))
 822		// Power7 or earlier
 823		set_dabr(brk);
 824	else
 825		// Shouldn't happen due to higher level checks
 826		WARN_ON_ONCE(1);
 827}
 828
 829void set_breakpoint(struct arch_hw_breakpoint *brk)
 830{
 831	preempt_disable();
 832	__set_breakpoint(brk);
 833	preempt_enable();
 834}
 835
 836/* Check if we have DAWR or DABR hardware */
 837bool ppc_breakpoint_available(void)
 838{
 839	if (cpu_has_feature(CPU_FTR_DAWR))
 840		return true; /* POWER8 DAWR */
 841	if (cpu_has_feature(CPU_FTR_ARCH_207S))
 842		return false; /* POWER9 with DAWR disabled */
 843	/* DABR: Everything but POWER8 and POWER9 */
 844	return true;
 845}
 846EXPORT_SYMBOL_GPL(ppc_breakpoint_available);
 847
 848#ifdef CONFIG_PPC64
 849DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
 850#endif
 851
 852static inline bool hw_brk_match(struct arch_hw_breakpoint *a,
 853			      struct arch_hw_breakpoint *b)
 854{
 855	if (a->address != b->address)
 856		return false;
 857	if (a->type != b->type)
 858		return false;
 859	if (a->len != b->len)
 860		return false;
 861	return true;
 862}
 863
 864#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 865
 866static inline bool tm_enabled(struct task_struct *tsk)
 867{
 868	return tsk && tsk->thread.regs && (tsk->thread.regs->msr & MSR_TM);
 869}
 870
 871static void tm_reclaim_thread(struct thread_struct *thr,
 872			      struct thread_info *ti, uint8_t cause)
 873{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 874	/*
 875	 * Use the current MSR TM suspended bit to track if we have
 876	 * checkpointed state outstanding.
 877	 * On signal delivery, we'd normally reclaim the checkpointed
 878	 * state to obtain stack pointer (see:get_tm_stackpointer()).
 879	 * This will then directly return to userspace without going
 880	 * through __switch_to(). However, if the stack frame is bad,
 881	 * we need to exit this thread which calls __switch_to() which
 882	 * will again attempt to reclaim the already saved tm state.
 883	 * Hence we need to check that we've not already reclaimed
 884	 * this state.
 885	 * We do this using the current MSR, rather tracking it in
 886	 * some specific thread_struct bit, as it has the additional
 887	 * benefit of checking for a potential TM bad thing exception.
 888	 */
 889	if (!MSR_TM_SUSPENDED(mfmsr()))
 890		return;
 891
 892	giveup_all(container_of(thr, struct task_struct, thread));
 893
 894	tm_reclaim(thr, cause);
 895
 896	/*
 897	 * If we are in a transaction and FP is off then we can't have
 898	 * used FP inside that transaction. Hence the checkpointed
 899	 * state is the same as the live state. We need to copy the
 900	 * live state to the checkpointed state so that when the
 901	 * transaction is restored, the checkpointed state is correct
 902	 * and the aborted transaction sees the correct state. We use
 903	 * ckpt_regs.msr here as that's what tm_reclaim will use to
 904	 * determine if it's going to write the checkpointed state or
 905	 * not. So either this will write the checkpointed registers,
 906	 * or reclaim will. Similarly for VMX.
 907	 */
 908	if ((thr->ckpt_regs.msr & MSR_FP) == 0)
 909		memcpy(&thr->ckfp_state, &thr->fp_state,
 910		       sizeof(struct thread_fp_state));
 911	if ((thr->ckpt_regs.msr & MSR_VEC) == 0)
 912		memcpy(&thr->ckvr_state, &thr->vr_state,
 913		       sizeof(struct thread_vr_state));
 914}
 915
 916void tm_reclaim_current(uint8_t cause)
 917{
 918	tm_enable();
 919	tm_reclaim_thread(&current->thread, current_thread_info(), cause);
 920}
 921
 922static inline void tm_reclaim_task(struct task_struct *tsk)
 923{
 924	/* We have to work out if we're switching from/to a task that's in the
 925	 * middle of a transaction.
 926	 *
 927	 * In switching we need to maintain a 2nd register state as
 928	 * oldtask->thread.ckpt_regs.  We tm_reclaim(oldproc); this saves the
 929	 * checkpointed (tbegin) state in ckpt_regs, ckfp_state and
 930	 * ckvr_state
 931	 *
 932	 * We also context switch (save) TFHAR/TEXASR/TFIAR in here.
 933	 */
 934	struct thread_struct *thr = &tsk->thread;
 935
 936	if (!thr->regs)
 937		return;
 938
 939	if (!MSR_TM_ACTIVE(thr->regs->msr))
 940		goto out_and_saveregs;
 941
 942	WARN_ON(tm_suspend_disabled);
 
 
 
 
 
 
 943
 944	TM_DEBUG("--- tm_reclaim on pid %d (NIP=%lx, "
 945		 "ccr=%lx, msr=%lx, trap=%lx)\n",
 946		 tsk->pid, thr->regs->nip,
 947		 thr->regs->ccr, thr->regs->msr,
 948		 thr->regs->trap);
 949
 950	tm_reclaim_thread(thr, task_thread_info(tsk), TM_CAUSE_RESCHED);
 951
 952	TM_DEBUG("--- tm_reclaim on pid %d complete\n",
 953		 tsk->pid);
 954
 955out_and_saveregs:
 956	/* Always save the regs here, even if a transaction's not active.
 957	 * This context-switches a thread's TM info SPRs.  We do it here to
 958	 * be consistent with the restore path (in recheckpoint) which
 959	 * cannot happen later in _switch().
 960	 */
 961	tm_save_sprs(thr);
 962}
 963
 964extern void __tm_recheckpoint(struct thread_struct *thread);
 
 965
 966void tm_recheckpoint(struct thread_struct *thread)
 
 967{
 968	unsigned long flags;
 969
 970	if (!(thread->regs->msr & MSR_TM))
 971		return;
 972
 973	/* We really can't be interrupted here as the TEXASR registers can't
 974	 * change and later in the trecheckpoint code, we have a userspace R1.
 975	 * So let's hard disable over this region.
 976	 */
 977	local_irq_save(flags);
 978	hard_irq_disable();
 979
 980	/* The TM SPRs are restored here, so that TEXASR.FS can be set
 981	 * before the trecheckpoint and no explosion occurs.
 982	 */
 983	tm_restore_sprs(thread);
 984
 985	__tm_recheckpoint(thread);
 986
 987	local_irq_restore(flags);
 988}
 989
 990static inline void tm_recheckpoint_new_task(struct task_struct *new)
 991{
 
 
 992	if (!cpu_has_feature(CPU_FTR_TM))
 993		return;
 994
 995	/* Recheckpoint the registers of the thread we're about to switch to.
 996	 *
 997	 * If the task was using FP, we non-lazily reload both the original and
 998	 * the speculative FP register states.  This is because the kernel
 999	 * doesn't see if/when a TM rollback occurs, so if we take an FP
1000	 * unavailable later, we are unable to determine which set of FP regs
1001	 * need to be restored.
1002	 */
1003	if (!tm_enabled(new))
1004		return;
1005
1006	if (!MSR_TM_ACTIVE(new->thread.regs->msr)){
1007		tm_restore_sprs(&new->thread);
1008		return;
1009	}
 
1010	/* Recheckpoint to restore original checkpointed register state. */
1011	TM_DEBUG("*** tm_recheckpoint of pid %d (new->msr 0x%lx)\n",
1012		 new->pid, new->thread.regs->msr);
1013
1014	tm_recheckpoint(&new->thread);
1015
1016	/*
1017	 * The checkpointed state has been restored but the live state has
1018	 * not, ensure all the math functionality is turned off to trigger
1019	 * restore_math() to reload.
1020	 */
1021	new->thread.regs->msr &= ~(MSR_FP | MSR_VEC | MSR_VSX);
 
 
 
 
 
 
 
 
 
 
 
1022
1023	TM_DEBUG("*** tm_recheckpoint of pid %d complete "
1024		 "(kernel msr 0x%lx)\n",
1025		 new->pid, mfmsr());
1026}
1027
1028static inline void __switch_to_tm(struct task_struct *prev,
1029		struct task_struct *new)
1030{
1031	if (cpu_has_feature(CPU_FTR_TM)) {
1032		if (tm_enabled(prev) || tm_enabled(new))
1033			tm_enable();
1034
1035		if (tm_enabled(prev)) {
1036			prev->thread.load_tm++;
1037			tm_reclaim_task(prev);
1038			if (!MSR_TM_ACTIVE(prev->thread.regs->msr) && prev->thread.load_tm == 0)
1039				prev->thread.regs->msr &= ~MSR_TM;
1040		}
1041
1042		tm_recheckpoint_new_task(new);
1043	}
1044}
1045
1046/*
1047 * This is called if we are on the way out to userspace and the
1048 * TIF_RESTORE_TM flag is set.  It checks if we need to reload
1049 * FP and/or vector state and does so if necessary.
1050 * If userspace is inside a transaction (whether active or
1051 * suspended) and FP/VMX/VSX instructions have ever been enabled
1052 * inside that transaction, then we have to keep them enabled
1053 * and keep the FP/VMX/VSX state loaded while ever the transaction
1054 * continues.  The reason is that if we didn't, and subsequently
1055 * got a FP/VMX/VSX unavailable interrupt inside a transaction,
1056 * we don't know whether it's the same transaction, and thus we
1057 * don't know which of the checkpointed state and the transactional
1058 * state to use.
1059 */
1060void restore_tm_state(struct pt_regs *regs)
1061{
1062	unsigned long msr_diff;
1063
1064	/*
1065	 * This is the only moment we should clear TIF_RESTORE_TM as
1066	 * it is here that ckpt_regs.msr and pt_regs.msr become the same
1067	 * again, anything else could lead to an incorrect ckpt_msr being
1068	 * saved and therefore incorrect signal contexts.
1069	 */
1070	clear_thread_flag(TIF_RESTORE_TM);
1071	if (!MSR_TM_ACTIVE(regs->msr))
1072		return;
1073
1074	msr_diff = current->thread.ckpt_regs.msr & ~regs->msr;
1075	msr_diff &= MSR_FP | MSR_VEC | MSR_VSX;
1076
1077	/* Ensure that restore_math() will restore */
1078	if (msr_diff & MSR_FP)
1079		current->thread.load_fp = 1;
1080#ifdef CONFIG_ALTIVEC
1081	if (cpu_has_feature(CPU_FTR_ALTIVEC) && msr_diff & MSR_VEC)
1082		current->thread.load_vec = 1;
1083#endif
1084	restore_math(regs);
1085
1086	regs->msr |= msr_diff;
1087}
1088
1089#else
1090#define tm_recheckpoint_new_task(new)
1091#define __switch_to_tm(prev, new)
1092#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
1093
1094static inline void save_sprs(struct thread_struct *t)
1095{
1096#ifdef CONFIG_ALTIVEC
1097	if (cpu_has_feature(CPU_FTR_ALTIVEC))
1098		t->vrsave = mfspr(SPRN_VRSAVE);
1099#endif
1100#ifdef CONFIG_PPC_BOOK3S_64
1101	if (cpu_has_feature(CPU_FTR_DSCR))
1102		t->dscr = mfspr(SPRN_DSCR);
1103
1104	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
1105		t->bescr = mfspr(SPRN_BESCR);
1106		t->ebbhr = mfspr(SPRN_EBBHR);
1107		t->ebbrr = mfspr(SPRN_EBBRR);
1108
1109		t->fscr = mfspr(SPRN_FSCR);
1110
1111		/*
1112		 * Note that the TAR is not available for use in the kernel.
1113		 * (To provide this, the TAR should be backed up/restored on
1114		 * exception entry/exit instead, and be in pt_regs.  FIXME,
1115		 * this should be in pt_regs anyway (for debug).)
1116		 */
1117		t->tar = mfspr(SPRN_TAR);
1118	}
1119#endif
1120
1121	thread_pkey_regs_save(t);
1122}
1123
1124static inline void restore_sprs(struct thread_struct *old_thread,
1125				struct thread_struct *new_thread)
1126{
1127#ifdef CONFIG_ALTIVEC
1128	if (cpu_has_feature(CPU_FTR_ALTIVEC) &&
1129	    old_thread->vrsave != new_thread->vrsave)
1130		mtspr(SPRN_VRSAVE, new_thread->vrsave);
1131#endif
1132#ifdef CONFIG_PPC_BOOK3S_64
1133	if (cpu_has_feature(CPU_FTR_DSCR)) {
1134		u64 dscr = get_paca()->dscr_default;
1135		if (new_thread->dscr_inherit)
 
 
1136			dscr = new_thread->dscr;
 
 
1137
1138		if (old_thread->dscr != dscr)
1139			mtspr(SPRN_DSCR, dscr);
 
 
 
1140	}
1141
1142	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
1143		if (old_thread->bescr != new_thread->bescr)
1144			mtspr(SPRN_BESCR, new_thread->bescr);
1145		if (old_thread->ebbhr != new_thread->ebbhr)
1146			mtspr(SPRN_EBBHR, new_thread->ebbhr);
1147		if (old_thread->ebbrr != new_thread->ebbrr)
1148			mtspr(SPRN_EBBRR, new_thread->ebbrr);
1149
1150		if (old_thread->fscr != new_thread->fscr)
1151			mtspr(SPRN_FSCR, new_thread->fscr);
1152
1153		if (old_thread->tar != new_thread->tar)
1154			mtspr(SPRN_TAR, new_thread->tar);
1155	}
1156
1157	if (cpu_has_feature(CPU_FTR_ARCH_300) &&
1158	    old_thread->tidr != new_thread->tidr)
1159		mtspr(SPRN_TIDR, new_thread->tidr);
1160#endif
1161
1162	thread_pkey_regs_restore(new_thread, old_thread);
1163}
1164
1165#ifdef CONFIG_PPC_BOOK3S_64
1166#define CP_SIZE 128
1167static const u8 dummy_copy_buffer[CP_SIZE] __attribute__((aligned(CP_SIZE)));
1168#endif
1169
1170struct task_struct *__switch_to(struct task_struct *prev,
1171	struct task_struct *new)
1172{
1173	struct thread_struct *new_thread, *old_thread;
1174	struct task_struct *last;
1175#ifdef CONFIG_PPC_BOOK3S_64
1176	struct ppc64_tlb_batch *batch;
1177#endif
1178
1179	new_thread = &new->thread;
1180	old_thread = &current->thread;
1181
1182	WARN_ON(!irqs_disabled());
1183
1184#ifdef CONFIG_PPC64
1185	/*
1186	 * Collect processor utilization data per process
1187	 */
1188	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
1189		struct cpu_usage *cu = this_cpu_ptr(&cpu_usage_array);
1190		long unsigned start_tb, current_tb;
1191		start_tb = old_thread->start_tb;
1192		cu->current_tb = current_tb = mfspr(SPRN_PURR);
1193		old_thread->accum_tb += (current_tb - start_tb);
1194		new_thread->start_tb = current_tb;
1195	}
1196#endif /* CONFIG_PPC64 */
1197
1198#ifdef CONFIG_PPC_BOOK3S_64
1199	batch = this_cpu_ptr(&ppc64_tlb_batch);
1200	if (batch->active) {
1201		current_thread_info()->local_flags |= _TLF_LAZY_MMU;
1202		if (batch->index)
1203			__flush_tlb_pending(batch);
1204		batch->active = 0;
1205	}
1206#endif /* CONFIG_PPC_BOOK3S_64 */
1207
1208#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1209	switch_booke_debug_regs(&new->thread.debug);
1210#else
1211/*
1212 * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would
1213 * schedule DABR
1214 */
1215#ifndef CONFIG_HAVE_HW_BREAKPOINT
1216	if (unlikely(!hw_brk_match(this_cpu_ptr(&current_brk), &new->thread.hw_brk)))
1217		__set_breakpoint(&new->thread.hw_brk);
1218#endif /* CONFIG_HAVE_HW_BREAKPOINT */
1219#endif
1220
1221	/*
1222	 * We need to save SPRs before treclaim/trecheckpoint as these will
1223	 * change a number of them.
1224	 */
1225	save_sprs(&prev->thread);
1226
 
 
1227	/* Save FPU, Altivec, VSX and SPE state */
1228	giveup_all(prev);
1229
1230	__switch_to_tm(prev, new);
 
 
 
 
 
1231
1232	if (!radix_enabled()) {
1233		/*
1234		 * We can't take a PMU exception inside _switch() since there
1235		 * is a window where the kernel stack SLB and the kernel stack
1236		 * are out of sync. Hard disable here.
1237		 */
1238		hard_irq_disable();
1239	}
1240
1241	/*
1242	 * Call restore_sprs() before calling _switch(). If we move it after
1243	 * _switch() then we miss out on calling it for new tasks. The reason
1244	 * for this is we manually create a stack frame for new tasks that
1245	 * directly returns through ret_from_fork() or
1246	 * ret_from_kernel_thread(). See copy_thread() for details.
1247	 */
1248	restore_sprs(old_thread, new_thread);
1249
1250	last = _switch(old_thread, new_thread);
1251
1252#ifdef CONFIG_PPC_BOOK3S_64
1253	if (current_thread_info()->local_flags & _TLF_LAZY_MMU) {
1254		current_thread_info()->local_flags &= ~_TLF_LAZY_MMU;
1255		batch = this_cpu_ptr(&ppc64_tlb_batch);
1256		batch->active = 1;
1257	}
1258
1259	if (current_thread_info()->task->thread.regs) {
1260		restore_math(current_thread_info()->task->thread.regs);
1261
1262		/*
1263		 * The copy-paste buffer can only store into foreign real
1264		 * addresses, so unprivileged processes can not see the
1265		 * data or use it in any way unless they have foreign real
1266		 * mappings. If the new process has the foreign real address
1267		 * mappings, we must issue a cp_abort to clear any state and
1268		 * prevent snooping, corruption or a covert channel.
1269		 *
1270		 * DD1 allows paste into normal system memory so we do an
1271		 * unpaired copy, rather than cp_abort, to clear the buffer,
1272		 * since cp_abort is quite expensive.
1273		 */
1274		if (current_thread_info()->task->thread.used_vas) {
1275			asm volatile(PPC_CP_ABORT);
1276		} else if (cpu_has_feature(CPU_FTR_POWER9_DD1)) {
1277			asm volatile(PPC_COPY(%0, %1)
1278					: : "r"(dummy_copy_buffer), "r"(0));
1279		}
1280	}
1281#endif /* CONFIG_PPC_BOOK3S_64 */
1282
1283	return last;
1284}
1285
1286static int instructions_to_print = 16;
1287
1288static void show_instructions(struct pt_regs *regs)
1289{
1290	int i;
1291	unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
1292			sizeof(int));
1293
1294	printk("Instruction dump:");
1295
1296	for (i = 0; i < instructions_to_print; i++) {
1297		int instr;
1298
1299		if (!(i % 8))
1300			pr_cont("\n");
1301
1302#if !defined(CONFIG_BOOKE)
1303		/* If executing with the IMMU off, adjust pc rather
1304		 * than print XXXXXXXX.
1305		 */
1306		if (!(regs->msr & MSR_IR))
1307			pc = (unsigned long)phys_to_virt(pc);
1308#endif
1309
1310		if (!__kernel_text_address(pc) ||
1311		     probe_kernel_address((unsigned int __user *)pc, instr)) {
1312			pr_cont("XXXXXXXX ");
1313		} else {
1314			if (regs->nip == pc)
1315				pr_cont("<%08x> ", instr);
1316			else
1317				pr_cont("%08x ", instr);
1318		}
1319
1320		pc += sizeof(int);
1321	}
1322
1323	pr_cont("\n");
1324}
1325
1326struct regbit {
1327	unsigned long bit;
1328	const char *name;
1329};
1330
1331static struct regbit msr_bits[] = {
1332#if defined(CONFIG_PPC64) && !defined(CONFIG_BOOKE)
1333	{MSR_SF,	"SF"},
1334	{MSR_HV,	"HV"},
1335#endif
1336	{MSR_VEC,	"VEC"},
1337	{MSR_VSX,	"VSX"},
1338#ifdef CONFIG_BOOKE
1339	{MSR_CE,	"CE"},
1340#endif
1341	{MSR_EE,	"EE"},
1342	{MSR_PR,	"PR"},
1343	{MSR_FP,	"FP"},
1344	{MSR_ME,	"ME"},
1345#ifdef CONFIG_BOOKE
1346	{MSR_DE,	"DE"},
1347#else
1348	{MSR_SE,	"SE"},
1349	{MSR_BE,	"BE"},
1350#endif
1351	{MSR_IR,	"IR"},
1352	{MSR_DR,	"DR"},
1353	{MSR_PMM,	"PMM"},
1354#ifndef CONFIG_BOOKE
1355	{MSR_RI,	"RI"},
1356	{MSR_LE,	"LE"},
1357#endif
1358	{0,		NULL}
1359};
1360
1361static void print_bits(unsigned long val, struct regbit *bits, const char *sep)
1362{
1363	const char *s = "";
1364
1365	for (; bits->bit; ++bits)
1366		if (val & bits->bit) {
1367			pr_cont("%s%s", s, bits->name);
1368			s = sep;
1369		}
1370}
1371
1372#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1373static struct regbit msr_tm_bits[] = {
1374	{MSR_TS_T,	"T"},
1375	{MSR_TS_S,	"S"},
1376	{MSR_TM,	"E"},
1377	{0,		NULL}
1378};
1379
1380static void print_tm_bits(unsigned long val)
1381{
1382/*
1383 * This only prints something if at least one of the TM bit is set.
1384 * Inside the TM[], the output means:
1385 *   E: Enabled		(bit 32)
1386 *   S: Suspended	(bit 33)
1387 *   T: Transactional	(bit 34)
1388 */
1389	if (val & (MSR_TM | MSR_TS_S | MSR_TS_T)) {
1390		pr_cont(",TM[");
1391		print_bits(val, msr_tm_bits, "");
1392		pr_cont("]");
1393	}
1394}
1395#else
1396static void print_tm_bits(unsigned long val) {}
1397#endif
1398
1399static void print_msr_bits(unsigned long val)
1400{
1401	pr_cont("<");
1402	print_bits(val, msr_bits, ",");
1403	print_tm_bits(val);
1404	pr_cont(">");
1405}
1406
1407#ifdef CONFIG_PPC64
1408#define REG		"%016lx"
1409#define REGS_PER_LINE	4
1410#define LAST_VOLATILE	13
1411#else
1412#define REG		"%08lx"
1413#define REGS_PER_LINE	8
1414#define LAST_VOLATILE	12
1415#endif
1416
1417void show_regs(struct pt_regs * regs)
1418{
1419	int i, trap;
1420
1421	show_regs_print_info(KERN_DEFAULT);
1422
1423	printk("NIP:  "REG" LR: "REG" CTR: "REG"\n",
1424	       regs->nip, regs->link, regs->ctr);
1425	printk("REGS: %px TRAP: %04lx   %s  (%s)\n",
1426	       regs, regs->trap, print_tainted(), init_utsname()->release);
1427	printk("MSR:  "REG" ", regs->msr);
1428	print_msr_bits(regs->msr);
1429	pr_cont("  CR: %08lx  XER: %08lx\n", regs->ccr, regs->xer);
1430	trap = TRAP(regs);
1431	if ((TRAP(regs) != 0xc00) && cpu_has_feature(CPU_FTR_CFAR))
1432		pr_cont("CFAR: "REG" ", regs->orig_gpr3);
1433	if (trap == 0x200 || trap == 0x300 || trap == 0x600)
1434#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
1435		pr_cont("DEAR: "REG" ESR: "REG" ", regs->dar, regs->dsisr);
1436#else
1437		pr_cont("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr);
1438#endif
1439#ifdef CONFIG_PPC64
1440	pr_cont("SOFTE: %ld ", regs->softe);
1441#endif
1442#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1443	if (MSR_TM_ACTIVE(regs->msr))
1444		pr_cont("\nPACATMSCRATCH: %016llx ", get_paca()->tm_scratch);
1445#endif
1446
1447	for (i = 0;  i < 32;  i++) {
1448		if ((i % REGS_PER_LINE) == 0)
1449			pr_cont("\nGPR%02d: ", i);
1450		pr_cont(REG " ", regs->gpr[i]);
1451		if (i == LAST_VOLATILE && !FULL_REGS(regs))
1452			break;
1453	}
1454	pr_cont("\n");
1455#ifdef CONFIG_KALLSYMS
1456	/*
1457	 * Lookup NIP late so we have the best change of getting the
1458	 * above info out without failing
1459	 */
1460	printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip);
1461	printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link);
1462#endif
1463	show_stack(current, (unsigned long *) regs->gpr[1]);
1464	if (!user_mode(regs))
1465		show_instructions(regs);
1466}
1467
 
 
 
 
1468void flush_thread(void)
1469{
1470#ifdef CONFIG_HAVE_HW_BREAKPOINT
1471	flush_ptrace_hw_breakpoint(current);
1472#else /* CONFIG_HAVE_HW_BREAKPOINT */
1473	set_debug_reg_defaults(&current->thread);
1474#endif /* CONFIG_HAVE_HW_BREAKPOINT */
1475}
1476
1477int set_thread_uses_vas(void)
1478{
1479#ifdef CONFIG_PPC_BOOK3S_64
1480	if (!cpu_has_feature(CPU_FTR_ARCH_300))
1481		return -EINVAL;
1482
1483	current->thread.used_vas = 1;
1484
1485	/*
1486	 * Even a process that has no foreign real address mapping can use
1487	 * an unpaired COPY instruction (to no real effect). Issue CP_ABORT
1488	 * to clear any pending COPY and prevent a covert channel.
1489	 *
1490	 * __switch_to() will issue CP_ABORT on future context switches.
1491	 */
1492	asm volatile(PPC_CP_ABORT);
1493
1494#endif /* CONFIG_PPC_BOOK3S_64 */
1495	return 0;
1496}
1497
1498#ifdef CONFIG_PPC64
1499static DEFINE_SPINLOCK(vas_thread_id_lock);
1500static DEFINE_IDA(vas_thread_ida);
1501
1502/*
1503 * We need to assign a unique thread id to each thread in a process.
1504 *
1505 * This thread id, referred to as TIDR, and separate from the Linux's tgid,
1506 * is intended to be used to direct an ASB_Notify from the hardware to the
1507 * thread, when a suitable event occurs in the system.
1508 *
1509 * One such event is a "paste" instruction in the context of Fast Thread
1510 * Wakeup (aka Core-to-core wake up in the Virtual Accelerator Switchboard
1511 * (VAS) in POWER9.
1512 *
1513 * To get a unique TIDR per process we could simply reuse task_pid_nr() but
1514 * the problem is that task_pid_nr() is not yet available copy_thread() is
1515 * called. Fixing that would require changing more intrusive arch-neutral
1516 * code in code path in copy_process()?.
1517 *
1518 * Further, to assign unique TIDRs within each process, we need an atomic
1519 * field (or an IDR) in task_struct, which again intrudes into the arch-
1520 * neutral code. So try to assign globally unique TIDRs for now.
1521 *
1522 * NOTE: TIDR 0 indicates that the thread does not need a TIDR value.
1523 *	 For now, only threads that expect to be notified by the VAS
1524 *	 hardware need a TIDR value and we assign values > 0 for those.
1525 */
1526#define MAX_THREAD_CONTEXT	((1 << 16) - 1)
1527static int assign_thread_tidr(void)
1528{
1529	int index;
1530	int err;
1531	unsigned long flags;
1532
1533again:
1534	if (!ida_pre_get(&vas_thread_ida, GFP_KERNEL))
1535		return -ENOMEM;
1536
1537	spin_lock_irqsave(&vas_thread_id_lock, flags);
1538	err = ida_get_new_above(&vas_thread_ida, 1, &index);
1539	spin_unlock_irqrestore(&vas_thread_id_lock, flags);
1540
1541	if (err == -EAGAIN)
1542		goto again;
1543	else if (err)
1544		return err;
1545
1546	if (index > MAX_THREAD_CONTEXT) {
1547		spin_lock_irqsave(&vas_thread_id_lock, flags);
1548		ida_remove(&vas_thread_ida, index);
1549		spin_unlock_irqrestore(&vas_thread_id_lock, flags);
1550		return -ENOMEM;
1551	}
1552
1553	return index;
1554}
1555
1556static void free_thread_tidr(int id)
1557{
1558	unsigned long flags;
1559
1560	spin_lock_irqsave(&vas_thread_id_lock, flags);
1561	ida_remove(&vas_thread_ida, id);
1562	spin_unlock_irqrestore(&vas_thread_id_lock, flags);
1563}
1564
1565/*
1566 * Clear any TIDR value assigned to this thread.
1567 */
1568void clear_thread_tidr(struct task_struct *t)
1569{
1570	if (!t->thread.tidr)
1571		return;
1572
1573	if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
1574		WARN_ON_ONCE(1);
1575		return;
1576	}
1577
1578	mtspr(SPRN_TIDR, 0);
1579	free_thread_tidr(t->thread.tidr);
1580	t->thread.tidr = 0;
1581}
1582
1583void arch_release_task_struct(struct task_struct *t)
1584{
1585	clear_thread_tidr(t);
1586}
1587
1588/*
1589 * Assign a unique TIDR (thread id) for task @t and set it in the thread
1590 * structure. For now, we only support setting TIDR for 'current' task.
1591 */
1592int set_thread_tidr(struct task_struct *t)
1593{
1594	int rc;
1595
1596	if (!cpu_has_feature(CPU_FTR_ARCH_300))
1597		return -EINVAL;
1598
1599	if (t != current)
1600		return -EINVAL;
1601
1602	if (t->thread.tidr)
1603		return 0;
1604
1605	rc = assign_thread_tidr();
1606	if (rc < 0)
1607		return rc;
1608
1609	t->thread.tidr = rc;
1610	mtspr(SPRN_TIDR, t->thread.tidr);
1611
1612	return 0;
1613}
1614EXPORT_SYMBOL_GPL(set_thread_tidr);
1615
1616#endif /* CONFIG_PPC64 */
1617
1618void
1619release_thread(struct task_struct *t)
1620{
1621}
1622
1623/*
1624 * this gets called so that we can store coprocessor state into memory and
1625 * copy the current task into the new thread.
1626 */
1627int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
1628{
1629	flush_all_to_thread(src);
1630	/*
1631	 * Flush TM state out so we can copy it.  __switch_to_tm() does this
1632	 * flush but it removes the checkpointed state from the current CPU and
1633	 * transitions the CPU out of TM mode.  Hence we need to call
1634	 * tm_recheckpoint_new_task() (on the same task) to restore the
1635	 * checkpointed state back and the TM mode.
1636	 *
1637	 * Can't pass dst because it isn't ready. Doesn't matter, passing
1638	 * dst is only important for __switch_to()
1639	 */
1640	__switch_to_tm(src, src);
 
1641
1642	*dst = *src;
1643
1644	clear_task_ebb(dst);
1645
1646	return 0;
1647}
1648
1649static void setup_ksp_vsid(struct task_struct *p, unsigned long sp)
1650{
1651#ifdef CONFIG_PPC_BOOK3S_64
1652	unsigned long sp_vsid;
1653	unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
1654
1655	if (radix_enabled())
1656		return;
1657
1658	if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
1659		sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T)
1660			<< SLB_VSID_SHIFT_1T;
1661	else
1662		sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M)
1663			<< SLB_VSID_SHIFT;
1664	sp_vsid |= SLB_VSID_KERNEL | llp;
1665	p->thread.ksp_vsid = sp_vsid;
1666#endif
1667}
1668
1669/*
1670 * Copy a thread..
1671 */
1672
1673/*
1674 * Copy architecture-specific thread state
1675 */
1676int copy_thread(unsigned long clone_flags, unsigned long usp,
1677		unsigned long kthread_arg, struct task_struct *p)
1678{
1679	struct pt_regs *childregs, *kregs;
1680	extern void ret_from_fork(void);
1681	extern void ret_from_kernel_thread(void);
1682	void (*f)(void);
1683	unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
1684	struct thread_info *ti = task_thread_info(p);
1685
1686	klp_init_thread_info(ti);
1687
1688	/* Copy registers */
1689	sp -= sizeof(struct pt_regs);
1690	childregs = (struct pt_regs *) sp;
1691	if (unlikely(p->flags & PF_KTHREAD)) {
1692		/* kernel thread */
 
1693		memset(childregs, 0, sizeof(struct pt_regs));
1694		childregs->gpr[1] = sp + sizeof(struct pt_regs);
1695		/* function */
1696		if (usp)
1697			childregs->gpr[14] = ppc_function_entry((void *)usp);
1698#ifdef CONFIG_PPC64
1699		clear_tsk_thread_flag(p, TIF_32BIT);
1700		childregs->softe = IRQS_ENABLED;
1701#endif
1702		childregs->gpr[15] = kthread_arg;
1703		p->thread.regs = NULL;	/* no user register state */
1704		ti->flags |= _TIF_RESTOREALL;
1705		f = ret_from_kernel_thread;
1706	} else {
1707		/* user thread */
1708		struct pt_regs *regs = current_pt_regs();
1709		CHECK_FULL_REGS(regs);
1710		*childregs = *regs;
1711		if (usp)
1712			childregs->gpr[1] = usp;
1713		p->thread.regs = childregs;
1714		childregs->gpr[3] = 0;  /* Result from fork() */
1715		if (clone_flags & CLONE_SETTLS) {
1716#ifdef CONFIG_PPC64
1717			if (!is_32bit_task())
1718				childregs->gpr[13] = childregs->gpr[6];
1719			else
1720#endif
1721				childregs->gpr[2] = childregs->gpr[6];
1722		}
1723
1724		f = ret_from_fork;
1725	}
1726	childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX);
1727	sp -= STACK_FRAME_OVERHEAD;
1728
1729	/*
1730	 * The way this works is that at some point in the future
1731	 * some task will call _switch to switch to the new task.
1732	 * That will pop off the stack frame created below and start
1733	 * the new task running at ret_from_fork.  The new task will
1734	 * do some house keeping and then return from the fork or clone
1735	 * system call, using the stack frame created above.
1736	 */
1737	((unsigned long *)sp)[0] = 0;
1738	sp -= sizeof(struct pt_regs);
1739	kregs = (struct pt_regs *) sp;
1740	sp -= STACK_FRAME_OVERHEAD;
1741	p->thread.ksp = sp;
1742#ifdef CONFIG_PPC32
1743	p->thread.ksp_limit = (unsigned long)task_stack_page(p) +
1744				_ALIGN_UP(sizeof(struct thread_info), 16);
1745#endif
1746#ifdef CONFIG_HAVE_HW_BREAKPOINT
1747	p->thread.ptrace_bps[0] = NULL;
1748#endif
1749
1750	p->thread.fp_save_area = NULL;
1751#ifdef CONFIG_ALTIVEC
1752	p->thread.vr_save_area = NULL;
1753#endif
1754
1755	setup_ksp_vsid(p, sp);
1756
1757#ifdef CONFIG_PPC64 
1758	if (cpu_has_feature(CPU_FTR_DSCR)) {
1759		p->thread.dscr_inherit = current->thread.dscr_inherit;
1760		p->thread.dscr = mfspr(SPRN_DSCR);
1761	}
1762	if (cpu_has_feature(CPU_FTR_HAS_PPR))
1763		p->thread.ppr = INIT_PPR;
1764
1765	p->thread.tidr = 0;
1766#endif
1767	kregs->nip = ppc_function_entry(f);
1768	return 0;
1769}
1770
1771/*
1772 * Set up a thread for executing a new program
1773 */
1774void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
1775{
1776#ifdef CONFIG_PPC64
1777	unsigned long load_addr = regs->gpr[2];	/* saved by ELF_PLAT_INIT */
1778#endif
1779
1780	/*
1781	 * If we exec out of a kernel thread then thread.regs will not be
1782	 * set.  Do it now.
1783	 */
1784	if (!current->thread.regs) {
1785		struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
1786		current->thread.regs = regs - 1;
1787	}
1788
1789#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1790	/*
1791	 * Clear any transactional state, we're exec()ing. The cause is
1792	 * not important as there will never be a recheckpoint so it's not
1793	 * user visible.
1794	 */
1795	if (MSR_TM_SUSPENDED(mfmsr()))
1796		tm_reclaim_current(0);
1797#endif
1798
1799	memset(regs->gpr, 0, sizeof(regs->gpr));
1800	regs->ctr = 0;
1801	regs->link = 0;
1802	regs->xer = 0;
1803	regs->ccr = 0;
1804	regs->gpr[1] = sp;
1805
1806	/*
1807	 * We have just cleared all the nonvolatile GPRs, so make
1808	 * FULL_REGS(regs) return true.  This is necessary to allow
1809	 * ptrace to examine the thread immediately after exec.
1810	 */
1811	regs->trap &= ~1UL;
1812
1813#ifdef CONFIG_PPC32
1814	regs->mq = 0;
1815	regs->nip = start;
1816	regs->msr = MSR_USER;
1817#else
1818	if (!is_32bit_task()) {
1819		unsigned long entry;
1820
1821		if (is_elf2_task()) {
1822			/* Look ma, no function descriptors! */
1823			entry = start;
1824
1825			/*
1826			 * Ulrich says:
1827			 *   The latest iteration of the ABI requires that when
1828			 *   calling a function (at its global entry point),
1829			 *   the caller must ensure r12 holds the entry point
1830			 *   address (so that the function can quickly
1831			 *   establish addressability).
1832			 */
1833			regs->gpr[12] = start;
1834			/* Make sure that's restored on entry to userspace. */
1835			set_thread_flag(TIF_RESTOREALL);
1836		} else {
1837			unsigned long toc;
1838
1839			/* start is a relocated pointer to the function
1840			 * descriptor for the elf _start routine.  The first
1841			 * entry in the function descriptor is the entry
1842			 * address of _start and the second entry is the TOC
1843			 * value we need to use.
1844			 */
1845			__get_user(entry, (unsigned long __user *)start);
1846			__get_user(toc, (unsigned long __user *)start+1);
1847
1848			/* Check whether the e_entry function descriptor entries
1849			 * need to be relocated before we can use them.
1850			 */
1851			if (load_addr != 0) {
1852				entry += load_addr;
1853				toc   += load_addr;
1854			}
1855			regs->gpr[2] = toc;
1856		}
1857		regs->nip = entry;
1858		regs->msr = MSR_USER64;
1859	} else {
1860		regs->nip = start;
1861		regs->gpr[2] = 0;
1862		regs->msr = MSR_USER32;
1863	}
1864#endif
1865#ifdef CONFIG_VSX
1866	current->thread.used_vsr = 0;
1867#endif
1868	current->thread.load_fp = 0;
1869	memset(&current->thread.fp_state, 0, sizeof(current->thread.fp_state));
1870	current->thread.fp_save_area = NULL;
1871#ifdef CONFIG_ALTIVEC
1872	memset(&current->thread.vr_state, 0, sizeof(current->thread.vr_state));
1873	current->thread.vr_state.vscr.u[3] = 0x00010000; /* Java mode disabled */
1874	current->thread.vr_save_area = NULL;
1875	current->thread.vrsave = 0;
1876	current->thread.used_vr = 0;
1877	current->thread.load_vec = 0;
1878#endif /* CONFIG_ALTIVEC */
1879#ifdef CONFIG_SPE
1880	memset(current->thread.evr, 0, sizeof(current->thread.evr));
1881	current->thread.acc = 0;
1882	current->thread.spefscr = 0;
1883	current->thread.used_spe = 0;
1884#endif /* CONFIG_SPE */
1885#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 
 
1886	current->thread.tm_tfhar = 0;
1887	current->thread.tm_texasr = 0;
1888	current->thread.tm_tfiar = 0;
1889	current->thread.load_tm = 0;
1890#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
1891
1892	thread_pkey_regs_init(&current->thread);
1893}
1894EXPORT_SYMBOL(start_thread);
1895
1896#define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
1897		| PR_FP_EXC_RES | PR_FP_EXC_INV)
1898
1899int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
1900{
1901	struct pt_regs *regs = tsk->thread.regs;
1902
1903	/* This is a bit hairy.  If we are an SPE enabled  processor
1904	 * (have embedded fp) we store the IEEE exception enable flags in
1905	 * fpexc_mode.  fpexc_mode is also used for setting FP exception
1906	 * mode (asyn, precise, disabled) for 'Classic' FP. */
1907	if (val & PR_FP_EXC_SW_ENABLE) {
1908#ifdef CONFIG_SPE
1909		if (cpu_has_feature(CPU_FTR_SPE)) {
1910			/*
1911			 * When the sticky exception bits are set
1912			 * directly by userspace, it must call prctl
1913			 * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
1914			 * in the existing prctl settings) or
1915			 * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
1916			 * the bits being set).  <fenv.h> functions
1917			 * saving and restoring the whole
1918			 * floating-point environment need to do so
1919			 * anyway to restore the prctl settings from
1920			 * the saved environment.
1921			 */
1922			tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
1923			tsk->thread.fpexc_mode = val &
1924				(PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
1925			return 0;
1926		} else {
1927			return -EINVAL;
1928		}
1929#else
1930		return -EINVAL;
1931#endif
1932	}
1933
1934	/* on a CONFIG_SPE this does not hurt us.  The bits that
1935	 * __pack_fe01 use do not overlap with bits used for
1936	 * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
1937	 * on CONFIG_SPE implementations are reserved so writing to
1938	 * them does not change anything */
1939	if (val > PR_FP_EXC_PRECISE)
1940		return -EINVAL;
1941	tsk->thread.fpexc_mode = __pack_fe01(val);
1942	if (regs != NULL && (regs->msr & MSR_FP) != 0)
1943		regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
1944			| tsk->thread.fpexc_mode;
1945	return 0;
1946}
1947
1948int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
1949{
1950	unsigned int val;
1951
1952	if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
1953#ifdef CONFIG_SPE
1954		if (cpu_has_feature(CPU_FTR_SPE)) {
1955			/*
1956			 * When the sticky exception bits are set
1957			 * directly by userspace, it must call prctl
1958			 * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
1959			 * in the existing prctl settings) or
1960			 * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
1961			 * the bits being set).  <fenv.h> functions
1962			 * saving and restoring the whole
1963			 * floating-point environment need to do so
1964			 * anyway to restore the prctl settings from
1965			 * the saved environment.
1966			 */
1967			tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
1968			val = tsk->thread.fpexc_mode;
1969		} else
1970			return -EINVAL;
1971#else
1972		return -EINVAL;
1973#endif
1974	else
1975		val = __unpack_fe01(tsk->thread.fpexc_mode);
1976	return put_user(val, (unsigned int __user *) adr);
1977}
1978
1979int set_endian(struct task_struct *tsk, unsigned int val)
1980{
1981	struct pt_regs *regs = tsk->thread.regs;
1982
1983	if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) ||
1984	    (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE)))
1985		return -EINVAL;
1986
1987	if (regs == NULL)
1988		return -EINVAL;
1989
1990	if (val == PR_ENDIAN_BIG)
1991		regs->msr &= ~MSR_LE;
1992	else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
1993		regs->msr |= MSR_LE;
1994	else
1995		return -EINVAL;
1996
1997	return 0;
1998}
1999
2000int get_endian(struct task_struct *tsk, unsigned long adr)
2001{
2002	struct pt_regs *regs = tsk->thread.regs;
2003	unsigned int val;
2004
2005	if (!cpu_has_feature(CPU_FTR_PPC_LE) &&
2006	    !cpu_has_feature(CPU_FTR_REAL_LE))
2007		return -EINVAL;
2008
2009	if (regs == NULL)
2010		return -EINVAL;
2011
2012	if (regs->msr & MSR_LE) {
2013		if (cpu_has_feature(CPU_FTR_REAL_LE))
2014			val = PR_ENDIAN_LITTLE;
2015		else
2016			val = PR_ENDIAN_PPC_LITTLE;
2017	} else
2018		val = PR_ENDIAN_BIG;
2019
2020	return put_user(val, (unsigned int __user *)adr);
2021}
2022
2023int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
2024{
2025	tsk->thread.align_ctl = val;
2026	return 0;
2027}
2028
2029int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
2030{
2031	return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
2032}
2033
2034static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
2035				  unsigned long nbytes)
2036{
2037	unsigned long stack_page;
2038	unsigned long cpu = task_cpu(p);
2039
2040	/*
2041	 * Avoid crashing if the stack has overflowed and corrupted
2042	 * task_cpu(p), which is in the thread_info struct.
2043	 */
2044	if (cpu < NR_CPUS && cpu_possible(cpu)) {
2045		stack_page = (unsigned long) hardirq_ctx[cpu];
2046		if (sp >= stack_page + sizeof(struct thread_struct)
2047		    && sp <= stack_page + THREAD_SIZE - nbytes)
2048			return 1;
2049
2050		stack_page = (unsigned long) softirq_ctx[cpu];
2051		if (sp >= stack_page + sizeof(struct thread_struct)
2052		    && sp <= stack_page + THREAD_SIZE - nbytes)
2053			return 1;
2054	}
2055	return 0;
2056}
2057
2058int validate_sp(unsigned long sp, struct task_struct *p,
2059		       unsigned long nbytes)
2060{
2061	unsigned long stack_page = (unsigned long)task_stack_page(p);
2062
2063	if (sp >= stack_page + sizeof(struct thread_struct)
2064	    && sp <= stack_page + THREAD_SIZE - nbytes)
2065		return 1;
2066
2067	return valid_irq_stack(sp, p, nbytes);
2068}
2069
2070EXPORT_SYMBOL(validate_sp);
2071
2072unsigned long get_wchan(struct task_struct *p)
2073{
2074	unsigned long ip, sp;
2075	int count = 0;
2076
2077	if (!p || p == current || p->state == TASK_RUNNING)
2078		return 0;
2079
2080	sp = p->thread.ksp;
2081	if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
2082		return 0;
2083
2084	do {
2085		sp = *(unsigned long *)sp;
2086		if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD) ||
2087		    p->state == TASK_RUNNING)
2088			return 0;
2089		if (count > 0) {
2090			ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE];
2091			if (!in_sched_functions(ip))
2092				return ip;
2093		}
2094	} while (count++ < 16);
2095	return 0;
2096}
2097
2098static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH;
2099
2100void show_stack(struct task_struct *tsk, unsigned long *stack)
2101{
2102	unsigned long sp, ip, lr, newsp;
2103	int count = 0;
2104	int firstframe = 1;
2105#ifdef CONFIG_FUNCTION_GRAPH_TRACER
2106	int curr_frame = current->curr_ret_stack;
2107	extern void return_to_handler(void);
2108	unsigned long rth = (unsigned long)return_to_handler;
2109#endif
2110
2111	sp = (unsigned long) stack;
2112	if (tsk == NULL)
2113		tsk = current;
2114	if (sp == 0) {
2115		if (tsk == current)
2116			sp = current_stack_pointer();
2117		else
2118			sp = tsk->thread.ksp;
2119	}
2120
2121	lr = 0;
2122	printk("Call Trace:\n");
2123	do {
2124		if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
2125			return;
2126
2127		stack = (unsigned long *) sp;
2128		newsp = stack[0];
2129		ip = stack[STACK_FRAME_LR_SAVE];
2130		if (!firstframe || ip != lr) {
2131			printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip);
2132#ifdef CONFIG_FUNCTION_GRAPH_TRACER
2133			if ((ip == rth) && curr_frame >= 0) {
2134				pr_cont(" (%pS)",
2135				       (void *)current->ret_stack[curr_frame].ret);
2136				curr_frame--;
2137			}
2138#endif
2139			if (firstframe)
2140				pr_cont(" (unreliable)");
2141			pr_cont("\n");
2142		}
2143		firstframe = 0;
2144
2145		/*
2146		 * See if this is an exception frame.
2147		 * We look for the "regshere" marker in the current frame.
2148		 */
2149		if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE)
2150		    && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
2151			struct pt_regs *regs = (struct pt_regs *)
2152				(sp + STACK_FRAME_OVERHEAD);
2153			lr = regs->link;
2154			printk("--- interrupt: %lx at %pS\n    LR = %pS\n",
2155			       regs->trap, (void *)regs->nip, (void *)lr);
2156			firstframe = 1;
2157		}
2158
2159		sp = newsp;
2160	} while (count++ < kstack_depth_to_print);
2161}
2162
2163#ifdef CONFIG_PPC64
2164/* Called with hard IRQs off */
2165void notrace __ppc64_runlatch_on(void)
2166{
2167	struct thread_info *ti = current_thread_info();
 
2168
2169	if (cpu_has_feature(CPU_FTR_ARCH_206)) {
2170		/*
2171		 * Least significant bit (RUN) is the only writable bit of
2172		 * the CTRL register, so we can avoid mfspr. 2.06 is not the
2173		 * earliest ISA where this is the case, but it's convenient.
2174		 */
2175		mtspr(SPRN_CTRLT, CTRL_RUNLATCH);
2176	} else {
2177		unsigned long ctrl;
2178
2179		/*
2180		 * Some architectures (e.g., Cell) have writable fields other
2181		 * than RUN, so do the read-modify-write.
2182		 */
2183		ctrl = mfspr(SPRN_CTRLF);
2184		ctrl |= CTRL_RUNLATCH;
2185		mtspr(SPRN_CTRLT, ctrl);
2186	}
2187
2188	ti->local_flags |= _TLF_RUNLATCH;
2189}
2190
2191/* Called with hard IRQs off */
2192void notrace __ppc64_runlatch_off(void)
2193{
2194	struct thread_info *ti = current_thread_info();
 
2195
2196	ti->local_flags &= ~_TLF_RUNLATCH;
2197
2198	if (cpu_has_feature(CPU_FTR_ARCH_206)) {
2199		mtspr(SPRN_CTRLT, 0);
2200	} else {
2201		unsigned long ctrl;
2202
2203		ctrl = mfspr(SPRN_CTRLF);
2204		ctrl &= ~CTRL_RUNLATCH;
2205		mtspr(SPRN_CTRLT, ctrl);
2206	}
2207}
2208#endif /* CONFIG_PPC64 */
2209
2210unsigned long arch_align_stack(unsigned long sp)
2211{
2212	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
2213		sp -= get_random_int() & ~PAGE_MASK;
2214	return sp & ~0xf;
2215}
2216
2217static inline unsigned long brk_rnd(void)
2218{
2219        unsigned long rnd = 0;
2220
2221	/* 8MB for 32bit, 1GB for 64bit */
2222	if (is_32bit_task())
2223		rnd = (get_random_long() % (1UL<<(23-PAGE_SHIFT)));
2224	else
2225		rnd = (get_random_long() % (1UL<<(30-PAGE_SHIFT)));
2226
2227	return rnd << PAGE_SHIFT;
2228}
2229
2230unsigned long arch_randomize_brk(struct mm_struct *mm)
2231{
2232	unsigned long base = mm->brk;
2233	unsigned long ret;
2234
2235#ifdef CONFIG_PPC_BOOK3S_64
2236	/*
2237	 * If we are using 1TB segments and we are allowed to randomise
2238	 * the heap, we can put it above 1TB so it is backed by a 1TB
2239	 * segment. Otherwise the heap will be in the bottom 1TB
2240	 * which always uses 256MB segments and this may result in a
2241	 * performance penalty. We don't need to worry about radix. For
2242	 * radix, mmu_highuser_ssize remains unchanged from 256MB.
2243	 */
2244	if (!is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T))
2245		base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T);
2246#endif
2247
2248	ret = PAGE_ALIGN(base + brk_rnd());
2249
2250	if (ret < mm->brk)
2251		return mm->brk;
2252
2253	return ret;
2254}
2255