/* * linux/arch/ppc64/kernel/process.c * * Derived from "arch/i386/kernel/process.c" * Copyright (C) 1995 Linus Torvalds * * Updated and modified by Cort Dougan (cort@cs.nmt.edu) and * Paul Mackerras (paulus@cs.anu.edu.au) * * PowerPC version * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include <linux/config.h>#include <linux/module.h>#include <linux/errno.h>#include <linux/sched.h>#include <linux/kernel.h>#include <linux/mm.h>#include <linux/smp.h>#include <linux/smp_lock.h>#include <linux/stddef.h>#include <linux/unistd.h>#include <linux/slab.h>#include <linux/user.h>#include <linux/elf.h>#include <linux/init.h>#include <linux/init_task.h>#include <linux/prctl.h>#include <linux/ptrace.h>#include <linux/kallsyms.h>#include <linux/interrupt.h>#include <linux/utsname.h>#include <linux/kprobes.h> #include <asm/pgtable.h>#include <asm/uaccess.h>#include <asm/system.h>#include <asm/io.h>#include <asm/processor.h>#include <asm/mmu.h>#include <asm/mmu_context.h>#include <asm/prom.h>#include <asm/ppcdebug.h>#include <asm/machdep.h>#include <asm/iSeries/HvCallHpt.h>#include <asm/cputable.h>#include <asm/sections.h>#include <asm/tlbflush.h>#include <asm/time.h> #ifndef CONFIG_SMPstruct task_struct *last_task_used_math = NULL;struct task_struct *last_task_used_altivec = NULL;#endif /* * Make sure the floating-point register state in the * the thread_struct is up to date for task tsk. */void flush_fp_to_thread(struct task_struct *tsk){ if (tsk->thread.regs) { /* * We need to disable preemption here because if we didn't, * another process could get scheduled after the regs->msr * test but before we have finished saving the FP registers * to the thread_struct. That process could take over the * FPU, and then when we get scheduled again we would store * bogus values for the remaining FP registers. */ preempt_disable(); if (tsk->thread.regs->msr & MSR_FP) {#ifdef CONFIG_SMP /* * This should only ever be called for current or * for a stopped child process. Since we save away * the FP register state on context switch on SMP, * there is something wrong if a stopped child appears * to still have its FP state in the CPU registers. */ BUG_ON(tsk != current);#endif giveup_fpu(current); } preempt_enable(); }} void enable_kernel_fp(void){ WARN_ON(preemptible()); #ifdef CONFIG_SMP if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) giveup_fpu(current); else giveup_fpu(NULL); /* just enables FP for kernel */#else giveup_fpu(last_task_used_math);#endif /* CONFIG_SMP */}EXPORT_SYMBOL(enable_kernel_fp); int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs){ if (!tsk->thread.regs) return 0; flush_fp_to_thread(current); memcpy(fpregs, &tsk->thread.fpr[0], sizeof(*fpregs)); return 1;} #ifdef CONFIG_ALTIVEC void enable_kernel_altivec(void){ WARN_ON(preemptible()); #ifdef CONFIG_SMP if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) giveup_altivec(current); else giveup_altivec(NULL); /* just enables FP for kernel */#else giveup_altivec(last_task_used_altivec);#endif /* CONFIG_SMP */}EXPORT_SYMBOL(enable_kernel_altivec); /* * Make sure the VMX/Altivec register state in the * the thread_struct is up to date for task tsk. */void flush_altivec_to_thread(struct task_struct *tsk){ if (tsk->thread.regs) { preempt_disable(); if (tsk->thread.regs->msr & MSR_VEC) {#ifdef CONFIG_SMP BUG_ON(tsk != current);#endif giveup_altivec(current); } preempt_enable(); }} int dump_task_altivec(struct pt_regs *regs, elf_vrregset_t *vrregs){ flush_altivec_to_thread(current); memcpy(vrregs, ¤t->thread.vr[0], sizeof(*vrregs)); return 1;} #endif /* CONFIG_ALTIVEC */ DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array); struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *new){ struct thread_struct *new_thread, *old_thread; unsigned long flags; struct task_struct *last; #ifdef CONFIG_SMP /* avoid complexity of lazy save/restore of fpu * by just saving it every time we switch out if * this task used the fpu during the last quantum. * * If it tries to use the fpu again, it'll trap and * reload its fp regs. So we don't have to do a restore * every switch, just a save. * -- Cort */ if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP)) giveup_fpu(prev);#ifdef CONFIG_ALTIVEC if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC)) giveup_altivec(prev);#endif /* CONFIG_ALTIVEC */#endif /* CONFIG_SMP */ #if defined(CONFIG_ALTIVEC) && !defined(CONFIG_SMP) /* Avoid the trap. On smp this this never happens since * we don't set last_task_used_altivec -- Cort */ if (new->thread.regs && last_task_used_altivec == new) new->thread.regs->msr |= MSR_VEC;#endif /* CONFIG_ALTIVEC */ flush_tlb_pending(); new_thread = &new->thread; old_thread = ¤t->thread; /* Collect purr utilization data per process and per processor wise *//* purr is nothing but processor time base */ #if defined(CONFIG_PPC_PSERIES) if (cur_cpu_spec->firmware_features & FW_FEATURE_SPLPAR) { struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array); long unsigned start_tb, current_tb; start_tb = old_thread->start_tb; cu->current_tb = current_tb = mfspr(SPRN_PURR); old_thread->accum_tb += (current_tb - start_tb); new_thread->start_tb = current_tb; }#endif local_irq_save(flags); last = _switch(old_thread, new_thread); local_irq_restore(flags); return last;} static int instructions_to_print = 16; static void show_instructions(struct pt_regs *regs){ int i; unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 * sizeof(int)); printk("Instruction dump:"); for (i = 0; i < instructions_to_print; i++) { int instr; if (!(i % 8)) printk("\n"); if (((REGION_ID(pc) != KERNEL_REGION_ID) && (REGION_ID(pc) != VMALLOC_REGION_ID)) || __get_user(instr, (unsigned int *)pc)) { printk("XXXXXXXX "); } else { if (regs->nip == pc) printk("<%08x> ", instr); else printk("%08x ", instr); } pc += sizeof(int); } printk("\n");} void show_regs(struct pt_regs * regs){ int i; unsigned long trap; printk("NIP: %016lX XER: %08X LR: %016lX CTR: %016lX\n", regs->nip, (unsigned int)regs->xer, regs->link, regs->ctr); printk("REGS: %p TRAP: %04lx %s (%s)\n", regs, regs->trap, print_tainted(), system_utsname.release); printk("MSR: %016lx EE: %01x PR: %01x FP: %01x ME: %01x " "IR/DR: %01x%01x CR: %08X\n", regs->msr, regs->msr&MSR_EE ? 1 : 0, regs->msr&MSR_PR ? 1 : 0, regs->msr & MSR_FP ? 1 : 0,regs->msr&MSR_ME ? 1 : 0, regs->msr&MSR_IR ? 1 : 0, regs->msr&MSR_DR ? 1 : 0, (unsigned int)regs->ccr); trap = TRAP(regs); printk("DAR: %016lx DSISR: %016lx\n", regs->dar, regs->dsisr); printk("TASK: %p[%d] '%s' THREAD: %p", current, current->pid, current->comm, current->thread_info); #ifdef CONFIG_SMP printk(" CPU: %d", smp_processor_id());#endif /* CONFIG_SMP */ for (i = 0; i < 32; i++) { if ((i % 4) == 0) { printk("\n" KERN_INFO "GPR%02d: ", i); } printk("%016lX ", regs->gpr[i]); if (i == 13 && !FULL_REGS(regs)) break; } printk("\n"); /* * Lookup NIP late so we have the best change of getting the * above info out without failing */ printk("NIP [%016lx] ", regs->nip); print_symbol("%s\n", regs->nip); printk("LR [%016lx] ", regs->link); print_symbol("%s\n", regs->link); show_stack(current, (unsigned long *)regs->gpr[1]); if (!user_mode(regs)) show_instructions(regs);} void exit_thread(void){ kprobe_flush_task(current); #ifndef CONFIG_SMP if (last_task_used_math == current) last_task_used_math = NULL;#ifdef CONFIG_ALTIVEC if (last_task_used_altivec == current) last_task_used_altivec = NULL;#endif /* CONFIG_ALTIVEC */#endif /* CONFIG_SMP */} void flush_thread(void){ struct thread_info *t = current_thread_info(); kprobe_flush_task(current); if (t->flags & _TIF_ABI_PENDING) t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT); #ifndef CONFIG_SMP if (last_task_used_math == current) last_task_used_math = NULL;#ifdef CONFIG_ALTIVEC if (last_task_used_altivec == current) last_task_used_altivec = NULL;#endif /* CONFIG_ALTIVEC */#endif /* CONFIG_SMP */} voidrelease_thread(struct task_struct *t){} /* * This gets called before we allocate a new thread and copy * the current task into it. */void prepare_to_copy(struct task_struct *tsk){ flush_fp_to_thread(current); flush_altivec_to_thread(current);} /* * Copy a thread.. */intcopy_thread(int nr, unsigned long clone_flags, unsigned long usp, unsigned long unused, struct task_struct *p, struct pt_regs *regs){ struct pt_regs *childregs, *kregs; extern void ret_from_fork(void); unsigned long sp = (unsigned long)p->thread_info + THREAD_SIZE; /* Copy registers */ sp -= sizeof(struct pt_regs); childregs = (struct pt_regs *) sp; *childregs = *regs; if ((childregs->msr & MSR_PR) == 0) { /* for kernel thread, set stackptr in new task */ childregs->gpr[1] = sp + sizeof(struct pt_regs); p->thread.regs = NULL; /* no user register state */ clear_ti_thread_flag(p->thread_info, TIF_32BIT); } else { childregs->gpr[1] = usp; p->thread.regs = childregs; if (clone_flags & CLONE_SETTLS) { if (test_thread_flag(TIF_32BIT)) childregs->gpr[2] = childregs->gpr[6]; else childregs->gpr[13] = childregs->gpr[6]; } } childregs->gpr[3] = 0; /* Result from fork() */ sp -= STACK_FRAME_OVERHEAD; /* * The way this works is that at some point in the future * some task will call _switch to switch to the new task. * That will pop off the stack frame created below and start * the new task running at ret_from_fork. The new task will * do some house keeping and then return from the fork or clone * system call, using the stack frame created above. */ sp -= sizeof(struct pt_regs); kregs = (struct pt_regs *) sp; sp -= STACK_FRAME_OVERHEAD; p->thread.ksp = sp; if (cpu_has_feature(CPU_FTR_SLB)) { unsigned long sp_vsid = get_kernel_vsid(sp); sp_vsid <<= SLB_VSID_SHIFT; sp_vsid |= SLB_VSID_KERNEL; if (cpu_has_feature(CPU_FTR_16M_PAGE)) sp_vsid |= SLB_VSID_L; p->thread.ksp_vsid = sp_vsid; } /* * The PPC64 ABI makes use of a TOC to contain function * pointers. The function (ret_from_except) is actually a pointer * to the TOC entry. The first entry is a pointer to the actual * function. */ kregs->nip = *((unsigned long *)ret_from_fork); return 0;} /* * Set up a thread for executing a new program */void start_thread(struct pt_regs *regs, unsigned long fdptr, unsigned long sp){ unsigned long entry, toc, load_addr = regs->gpr[2]; /* fdptr is a relocated pointer to the function descriptor for * the elf _start routine. The first entry in the function * descriptor is the entry address of _start and the second * entry is the TOC value we need to use. */ set_fs(USER_DS); __get_user(entry, (unsigned long __user *)fdptr); __get_user(toc, (unsigned long __user *)fdptr+1); /* Check whether the e_entry function descriptor entries * need to be relocated before we can use them. */ if (load_addr != 0) { entry += load_addr; toc += load_addr; } /* * If we exec out of a kernel thread then thread.regs will not be * set. Do it now. */ if (!current->thread.regs) { unsigned long childregs = (unsigned long)current->thread_info + THREAD_SIZE; childregs -= sizeof(struct pt_regs); current->thread.regs = (struct pt_regs *)childregs; } regs->nip = entry; regs->gpr[1] = sp; regs->gpr[2] = toc; regs->msr = MSR_USER64;#ifndef CONFIG_SMP if (last_task_used_math == current) last_task_used_math = 0;#endif /* CONFIG_SMP */ memset(current->thread.fpr, 0, sizeof(current->thread.fpr)); current->thread.fpscr = 0;#ifdef CONFIG_ALTIVEC#ifndef CONFIG_SMP if (last_task_used_altivec == current) last_task_used_altivec = 0;#endif /* CONFIG_SMP */ memset(current->thread.vr, 0, sizeof(current->thread.vr)); current->thread.vscr.u[0] = 0; current->thread.vscr.u[1] = 0; current->thread.vscr.u[2] = 0; current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */ current->thread.vrsave = 0; current->thread.used_vr = 0;#endif /* CONFIG_ALTIVEC */}EXPORT_SYMBOL(start_thread); int set_fpexc_mode(struct task_struct *tsk, unsigned int val){ struct pt_regs *regs = tsk->thread.regs; if (val > PR_FP_EXC_PRECISE) return -EINVAL; tsk->thread.fpexc_mode = __pack_fe01(val); if (regs != NULL && (regs->msr & MSR_FP) != 0) regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1)) | tsk->thread.fpexc_mode; return 0;} int get_fpexc_mode(struct task_struct *tsk, unsigned long adr){ unsigned int val;Lines 1–500 of 681. Load more
/* * linux/arch/ppc64/kernel/process.c * * Derived from "arch/i386/kernel/process.c" * Copyright (C) 1995 Linus Torvalds * * Updated and modified by Cort Dougan (cort@cs.nmt.edu) and * Paul Mackerras (paulus@cs.anu.edu.au) * * PowerPC version * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include <linux/config.h> #include <linux/module.h> #include <linux/errno.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/smp.h> #include <linux/smp_lock.h> #include <linux/stddef.h> #include <linux/unistd.h> #include <linux/slab.h> #include <linux/user.h> #include <linux/elf.h> #include <linux/init.h> #include <linux/init_task.h> #include <linux/prctl.h> #include <linux/ptrace.h> #include <linux/kallsyms.h> #include <linux/interrupt.h> #include <linux/utsname.h> #include <linux/kprobes.h> #include <asm/pgtable.h> #include <asm/uaccess.h> #include <asm/system.h> #include <asm/io.h> #include <asm/processor.h> #include <asm/mmu.h> #include <asm/mmu_context.h> #include <asm/prom.h> #include <asm/ppcdebug.h> #include <asm/machdep.h> #include <asm/iSeries/HvCallHpt.h> #include <asm/cputable.h> #include <asm/sections.h> #include <asm/tlbflush.h> #include <asm/time.h> #ifndef CONFIG_SMP struct task_struct *last_task_used_math = NULL; struct task_struct *last_task_used_altivec = NULL; #endif /* * Make sure the floating-point register state in the * the thread_struct is up to date for task tsk. */ void flush_fp_to_thread(struct task_struct *tsk) { if (tsk->thread.regs) { /* * We need to disable preemption here because if we didn't, * another process could get scheduled after the regs->msr * test but before we have finished saving the FP registers * to the thread_struct. That process could take over the * FPU, and then when we get scheduled again we would store * bogus values for the remaining FP registers. */ preempt_disable(); if (tsk->thread.regs->msr & MSR_FP) { #ifdef CONFIG_SMP /* * This should only ever be called for current or * for a stopped child process. Since we save away * the FP register state on context switch on SMP, * there is something wrong if a stopped child appears * to still have its FP state in the CPU registers. */ BUG_ON(tsk != current); #endif giveup_fpu(current); } preempt_enable(); } } void enable_kernel_fp(void) { WARN_ON(preemptible()); #ifdef CONFIG_SMP if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) giveup_fpu(current); else giveup_fpu(NULL); /* just enables FP for kernel */ #else giveup_fpu(last_task_used_math); #endif /* CONFIG_SMP */ } EXPORT_SYMBOL(enable_kernel_fp); int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs) { if (!tsk->thread.regs) return 0; flush_fp_to_thread(current); memcpy(fpregs, &tsk->thread.fpr[0], sizeof(*fpregs)); return 1; } #ifdef CONFIG_ALTIVEC void enable_kernel_altivec(void) { WARN_ON(preemptible()); #ifdef CONFIG_SMP if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) giveup_altivec(current); else giveup_altivec(NULL); /* just enables FP for kernel */ #else giveup_altivec(last_task_used_altivec); #endif /* CONFIG_SMP */ } EXPORT_SYMBOL(enable_kernel_altivec); /* * Make sure the VMX/Altivec register state in the * the thread_struct is up to date for task tsk. */ void flush_altivec_to_thread(struct task_struct *tsk) { if (tsk->thread.regs) { preempt_disable(); if (tsk->thread.regs->msr & MSR_VEC) { #ifdef CONFIG_SMP BUG_ON(tsk != current); #endif giveup_altivec(current); } preempt_enable(); } } int dump_task_altivec(struct pt_regs *regs, elf_vrregset_t *vrregs) { flush_altivec_to_thread(current); memcpy(vrregs, ¤t->thread.vr[0], sizeof(*vrregs)); return 1; } #endif /* CONFIG_ALTIVEC */ DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array); struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *new) { struct thread_struct *new_thread, *old_thread; unsigned long flags; struct task_struct *last; #ifdef CONFIG_SMP /* avoid complexity of lazy save/restore of fpu * by just saving it every time we switch out if * this task used the fpu during the last quantum. * * If it tries to use the fpu again, it'll trap and * reload its fp regs. So we don't have to do a restore * every switch, just a save. * -- Cort */ if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP)) giveup_fpu(prev); #ifdef CONFIG_ALTIVEC if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC)) giveup_altivec(prev); #endif /* CONFIG_ALTIVEC */ #endif /* CONFIG_SMP */ #if defined(CONFIG_ALTIVEC) && !defined(CONFIG_SMP) /* Avoid the trap. On smp this this never happens since * we don't set last_task_used_altivec -- Cort */ if (new->thread.regs && last_task_used_altivec == new) new->thread.regs->msr |= MSR_VEC; #endif /* CONFIG_ALTIVEC */ flush_tlb_pending(); new_thread = &new->thread; old_thread = ¤t->thread; /* Collect purr utilization data per process and per processor wise */ /* purr is nothing but processor time base */ #if defined(CONFIG_PPC_PSERIES) if (cur_cpu_spec->firmware_features & FW_FEATURE_SPLPAR) { struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array); long unsigned start_tb, current_tb; start_tb = old_thread->start_tb; cu->current_tb = current_tb = mfspr(SPRN_PURR); old_thread->accum_tb += (current_tb - start_tb); new_thread->start_tb = current_tb; } #endif local_irq_save(flags); last = _switch(old_thread, new_thread); local_irq_restore(flags); return last; } static int instructions_to_print = 16; static void show_instructions(struct pt_regs *regs) { int i; unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 * sizeof(int)); printk("Instruction dump:"); for (i = 0; i < instructions_to_print; i++) { int instr; if (!(i % 8)) printk("\n"); if (((REGION_ID(pc) != KERNEL_REGION_ID) && (REGION_ID(pc) != VMALLOC_REGION_ID)) || __get_user(instr, (unsigned int *)pc)) { printk("XXXXXXXX "); } else { if (regs->nip == pc) printk("<%08x> ", instr); else printk("%08x ", instr); } pc += sizeof(int); } printk("\n"); } void show_regs(struct pt_regs * regs) { int i; unsigned long trap; printk("NIP: %016lX XER: %08X LR: %016lX CTR: %016lX\n", regs->nip, (unsigned int)regs->xer, regs->link, regs->ctr); printk("REGS: %p TRAP: %04lx %s (%s)\n", regs, regs->trap, print_tainted(), system_utsname.release); printk("MSR: %016lx EE: %01x PR: %01x FP: %01x ME: %01x " "IR/DR: %01x%01x CR: %08X\n", regs->msr, regs->msr&MSR_EE ? 1 : 0, regs->msr&MSR_PR ? 1 : 0, regs->msr & MSR_FP ? 1 : 0,regs->msr&MSR_ME ? 1 : 0, regs->msr&MSR_IR ? 1 : 0, regs->msr&MSR_DR ? 1 : 0, (unsigned int)regs->ccr); trap = TRAP(regs); printk("DAR: %016lx DSISR: %016lx\n", regs->dar, regs->dsisr); printk("TASK: %p[%d] '%s' THREAD: %p", current, current->pid, current->comm, current->thread_info); #ifdef CONFIG_SMP printk(" CPU: %d", smp_processor_id()); #endif /* CONFIG_SMP */ for (i = 0; i < 32; i++) { if ((i % 4) == 0) { printk("\n" KERN_INFO "GPR%02d: ", i); } printk("%016lX ", regs->gpr[i]); if (i == 13 && !FULL_REGS(regs)) break; } printk("\n"); /* * Lookup NIP late so we have the best change of getting the * above info out without failing */ printk("NIP [%016lx] ", regs->nip); print_symbol("%s\n", regs->nip); printk("LR [%016lx] ", regs->link); print_symbol("%s\n", regs->link); show_stack(current, (unsigned long *)regs->gpr[1]); if (!user_mode(regs)) show_instructions(regs); } void exit_thread(void) { kprobe_flush_task(current); #ifndef CONFIG_SMP if (last_task_used_math == current) last_task_used_math = NULL; #ifdef CONFIG_ALTIVEC if (last_task_used_altivec == current) last_task_used_altivec = NULL; #endif /* CONFIG_ALTIVEC */ #endif /* CONFIG_SMP */ } void flush_thread(void) { struct thread_info *t = current_thread_info(); kprobe_flush_task(current); if (t->flags & _TIF_ABI_PENDING) t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT); #ifndef CONFIG_SMP if (last_task_used_math == current) last_task_used_math = NULL; #ifdef CONFIG_ALTIVEC if (last_task_used_altivec == current) last_task_used_altivec = NULL; #endif /* CONFIG_ALTIVEC */ #endif /* CONFIG_SMP */ } void release_thread(struct task_struct *t) { } /* * This gets called before we allocate a new thread and copy * the current task into it. */ void prepare_to_copy(struct task_struct *tsk) { flush_fp_to_thread(current); flush_altivec_to_thread(current); } /* * Copy a thread.. */ int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, unsigned long unused, struct task_struct *p, struct pt_regs *regs) { struct pt_regs *childregs, *kregs; extern void ret_from_fork(void); unsigned long sp = (unsigned long)p->thread_info + THREAD_SIZE; /* Copy registers */ sp -= sizeof(struct pt_regs); childregs = (struct pt_regs *) sp; *childregs = *regs; if ((childregs->msr & MSR_PR) == 0) { /* for kernel thread, set stackptr in new task */ childregs->gpr[1] = sp + sizeof(struct pt_regs); p->thread.regs = NULL; /* no user register state */ clear_ti_thread_flag(p->thread_info, TIF_32BIT); } else { childregs->gpr[1] = usp; p->thread.regs = childregs; if (clone_flags & CLONE_SETTLS) { if (test_thread_flag(TIF_32BIT)) childregs->gpr[2] = childregs->gpr[6]; else childregs->gpr[13] = childregs->gpr[6]; } } childregs->gpr[3] = 0; /* Result from fork() */ sp -= STACK_FRAME_OVERHEAD; /* * The way this works is that at some point in the future * some task will call _switch to switch to the new task. * That will pop off the stack frame created below and start * the new task running at ret_from_fork. The new task will * do some house keeping and then return from the fork or clone * system call, using the stack frame created above. */ sp -= sizeof(struct pt_regs); kregs = (struct pt_regs *) sp; sp -= STACK_FRAME_OVERHEAD; p->thread.ksp = sp; if (cpu_has_feature(CPU_FTR_SLB)) { unsigned long sp_vsid = get_kernel_vsid(sp); sp_vsid <<= SLB_VSID_SHIFT; sp_vsid |= SLB_VSID_KERNEL; if (cpu_has_feature(CPU_FTR_16M_PAGE)) sp_vsid |= SLB_VSID_L; p->thread.ksp_vsid = sp_vsid; } /* * The PPC64 ABI makes use of a TOC to contain function * pointers. The function (ret_from_except) is actually a pointer * to the TOC entry. The first entry is a pointer to the actual * function. */ kregs->nip = *((unsigned long *)ret_from_fork); return 0; } /* * Set up a thread for executing a new program */ void start_thread(struct pt_regs *regs, unsigned long fdptr, unsigned long sp) { unsigned long entry, toc, load_addr = regs->gpr[2]; /* fdptr is a relocated pointer to the function descriptor for * the elf _start routine. The first entry in the function * descriptor is the entry address of _start and the second * entry is the TOC value we need to use. */ set_fs(USER_DS); __get_user(entry, (unsigned long __user *)fdptr); __get_user(toc, (unsigned long __user *)fdptr+1); /* Check whether the e_entry function descriptor entries * need to be relocated before we can use them. */ if (load_addr != 0) { entry += load_addr; toc += load_addr; } /* * If we exec out of a kernel thread then thread.regs will not be * set. Do it now. */ if (!current->thread.regs) { unsigned long childregs = (unsigned long)current->thread_info + THREAD_SIZE; childregs -= sizeof(struct pt_regs); current->thread.regs = (struct pt_regs *)childregs; } regs->nip = entry; regs->gpr[1] = sp; regs->gpr[2] = toc; regs->msr = MSR_USER64; #ifndef CONFIG_SMP if (last_task_used_math == current) last_task_used_math = 0; #endif /* CONFIG_SMP */ memset(current->thread.fpr, 0, sizeof(current->thread.fpr)); current->thread.fpscr = 0; #ifdef CONFIG_ALTIVEC #ifndef CONFIG_SMP if (last_task_used_altivec == current) last_task_used_altivec = 0; #endif /* CONFIG_SMP */ memset(current->thread.vr, 0, sizeof(current->thread.vr)); current->thread.vscr.u[0] = 0; current->thread.vscr.u[1] = 0; current->thread.vscr.u[2] = 0; current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */ current->thread.vrsave = 0; current->thread.used_vr = 0; #endif /* CONFIG_ALTIVEC */ } EXPORT_SYMBOL(start_thread); int set_fpexc_mode(struct task_struct *tsk, unsigned int val) { struct pt_regs *regs = tsk->thread.regs; if (val > PR_FP_EXC_PRECISE) return -EINVAL; tsk->thread.fpexc_mode = __pack_fe01(val); if (regs != NULL && (regs->msr & MSR_FP) != 0) regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1)) | tsk->thread.fpexc_mode; return 0; } int get_fpexc_mode(struct task_struct *tsk, unsigned long adr) { unsigned int val;