diff options
Diffstat (limited to 'arch/powerpc/kernel/process.c')
| -rw-r--r-- | arch/powerpc/kernel/process.c | 726 |
1 files changed, 726 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c new file mode 100644 index 00000000000..e3946769dd8 --- /dev/null +++ b/arch/powerpc/kernel/process.c @@ -0,0 +1,726 @@ +/* + * arch/ppc/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/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/ptrace.h> +#include <linux/slab.h> +#include <linux/user.h> +#include <linux/elf.h> +#include <linux/init.h> +#include <linux/prctl.h> +#include <linux/init_task.h> +#include <linux/module.h> +#include <linux/kallsyms.h> +#include <linux/mqueue.h> +#include <linux/hardirq.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/prom.h> + +extern unsigned long _get_SP(void); + +#ifndef CONFIG_SMP +struct task_struct *last_task_used_math = NULL; +struct task_struct *last_task_used_altivec = NULL; +struct task_struct *last_task_used_spe = NULL; +#endif + +static struct fs_struct init_fs = INIT_FS; +static struct files_struct init_files = INIT_FILES; +static struct signal_struct init_signals = INIT_SIGNALS(init_signals); +static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand); +struct mm_struct init_mm = INIT_MM(init_mm); +EXPORT_SYMBOL(init_mm); + +/* this is 8kB-aligned so we can get to the thread_info struct + at the base of it from the stack pointer with 1 integer instruction. */ +union thread_union init_thread_union + __attribute__((__section__(".data.init_task"))) = +{ INIT_THREAD_INFO(init_task) }; + +/* initial task structure */ +struct task_struct init_task = INIT_TASK(init_task); +EXPORT_SYMBOL(init_task); + +/* only used to get secondary processor up */ +struct task_struct *current_set[NR_CPUS] = {&init_task, }; + +/* + * 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 enable AltiVec for kernel - force */ +#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 */ + +#ifdef CONFIG_SPE + +void enable_kernel_spe(void) +{ + WARN_ON(preemptible()); + +#ifdef CONFIG_SMP + if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) + giveup_spe(current); + else + giveup_spe(NULL); /* just enable SPE for kernel - force */ +#else + giveup_spe(last_task_used_spe); +#endif /* __SMP __ */ +} +EXPORT_SYMBOL(enable_kernel_spe); + +void flush_spe_to_thread(struct task_struct *tsk) +{ + if (tsk->thread.regs) { + preempt_disable(); + if (tsk->thread.regs->msr & MSR_SPE) { +#ifdef CONFIG_SMP + BUG_ON(tsk != current); +#endif + giveup_spe(current); + } + preempt_enable(); + } +} + +int dump_spe(struct pt_regs *regs, elf_vrregset_t *evrregs) +{ + flush_spe_to_thread(current); + /* We copy u32 evr[32] + u64 acc + u32 spefscr -> 35 */ + memcpy(evrregs, ¤t->thread.evr[0], sizeof(u32) * 35); + return 1; +} +#endif /* CONFIG_SPE */ + +static void set_dabr_spr(unsigned long val) +{ + mtspr(SPRN_DABR, val); +} + +int set_dabr(unsigned long dabr) +{ + int ret = 0; + +#ifdef CONFIG_PPC64 + if (firmware_has_feature(FW_FEATURE_XDABR)) { + /* We want to catch accesses from kernel and userspace */ + unsigned long flags = H_DABRX_KERNEL|H_DABRX_USER; + ret = plpar_set_xdabr(dabr, flags); + } else if (firmware_has_feature(FW_FEATURE_DABR)) { + ret = plpar_set_dabr(dabr); + } else +#endif + set_dabr_spr(dabr); + + return ret; +} + +static DEFINE_PER_CPU(unsigned long, current_dabr); + +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 the previous thread used altivec in the last quantum + * (thus changing altivec regs) then save them. + * We used to check the VRSAVE register but not all apps + * set it, so we don't rely on it now (and in fact we need + * to save & restore VSCR even if VRSAVE == 0). -- paulus + * + * On SMP we always save/restore altivec regs just to avoid the + * complexity of changing processors. + * -- Cort + */ + if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC)) + giveup_altivec(prev); + /* 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 */ +#ifdef CONFIG_SPE + /* + * If the previous thread used spe in the last quantum + * (thus changing spe regs) then save them. + * + * On SMP we always save/restore spe regs just to avoid the + * complexity of changing processors. + */ + if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE))) + giveup_spe(prev); + /* Avoid the trap. On smp this this never happens since + * we don't set last_task_used_spe + */ + if (new->thread.regs && last_task_used_spe == new) + new->thread.regs->msr |= MSR_SPE; +#endif /* CONFIG_SPE */ +#endif /* CONFIG_SMP */ + +#ifdef CONFIG_PPC64 /* for now */ + if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) { + set_dabr(new->thread.dabr); + __get_cpu_var(current_dabr) = new->thread.dabr; + } +#endif + + new_thread = &new->thread; + old_thread = ¤t->thread; + local_irq_save(flags); + last = _switch(old_thread, new_thread); + + local_irq_restore(flags); + + return last; +} + +void show_regs(struct pt_regs * regs) +{ + int i, trap; + + printk("NIP: %08lX LR: %08lX SP: %08lX REGS: %p TRAP: %04lx %s\n", + regs->nip, regs->link, regs->gpr[1], regs, regs->trap, + print_tainted()); + printk("MSR: %08lx EE: %01x PR: %01x FP: %01x ME: %01x IR/DR: %01x%01x\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); + trap = TRAP(regs); + if (trap == 0x300 || trap == 0x600) + printk("DAR: %08lX, DSISR: %08lX\n", regs->dar, regs->dsisr); + printk("TASK = %p[%d] '%s' THREAD: %p\n", + current, current->pid, current->comm, current->thread_info); + printk("Last syscall: %ld ", current->thread.last_syscall); + +#ifdef CONFIG_SMP + printk(" CPU: %d", smp_processor_id()); +#endif /* CONFIG_SMP */ + + for (i = 0; i < 32; i++) { + long r; + if ((i % 8) == 0) + printk("\n" KERN_INFO "GPR%02d: ", i); + if (__get_user(r, ®s->gpr[i])) + break; + printk("%08lX ", r); + if (i == 12 && !FULL_REGS(regs)) + break; + } + printk("\n"); +#ifdef CONFIG_KALLSYMS + /* + * Lookup NIP late so we have the best change of getting the + * above info out without failing + */ + printk("NIP [%08lx] ", regs->nip); + print_symbol("%s\n", regs->nip); + printk("LR [%08lx] ", regs->link); + print_symbol("%s\n", regs->link); +#endif + show_stack(current, (unsigned long *) regs->gpr[1]); +} + +void exit_thread(void) +{ +#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 */ +#ifdef CONFIG_SPE + if (last_task_used_spe == current) + last_task_used_spe = NULL; +#endif +#endif /* CONFIG_SMP */ +} + +void flush_thread(void) +{ +#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 */ +#ifdef CONFIG_SPE + if (last_task_used_spe == current) + last_task_used_spe = NULL; +#endif +#endif /* CONFIG_SMP */ + +#ifdef CONFIG_PPC64 /* for now */ + if (current->thread.dabr) { + current->thread.dabr = 0; + set_dabr(0); + } +#endif +} + +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); + flush_spe_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; + unsigned long childframe; + + CHECK_FULL_REGS(regs); + /* Copy registers */ + sp -= sizeof(struct pt_regs); + childregs = (struct pt_regs *) sp; + *childregs = *regs; + if ((childregs->msr & MSR_PR) == 0) { + /* for kernel thread, set `current' and stackptr in new task */ + childregs->gpr[1] = sp + sizeof(struct pt_regs); + childregs->gpr[2] = (unsigned long) p; + p->thread.regs = NULL; /* no user register state */ + } else { + childregs->gpr[1] = usp; + p->thread.regs = childregs; + if (clone_flags & CLONE_SETTLS) + childregs->gpr[2] = childregs->gpr[6]; + } + childregs->gpr[3] = 0; /* Result from fork() */ + sp -= STACK_FRAME_OVERHEAD; + childframe = sp; + + /* + * 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; + kregs->nip = (unsigned long)ret_from_fork; + + p->thread.last_syscall = -1; + + return 0; +} + +/* + * Set up a thread for executing a new program + */ +void start_thread(struct pt_regs *regs, unsigned long nip, unsigned long sp) +{ + set_fs(USER_DS); + memset(regs->gpr, 0, sizeof(regs->gpr)); + regs->ctr = 0; + regs->link = 0; + regs->xer = 0; + regs->ccr = 0; + regs->mq = 0; + regs->nip = nip; + regs->gpr[1] = sp; + regs->msr = MSR_USER; +#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 +#ifdef CONFIG_SPE + if (last_task_used_spe == current) + last_task_used_spe = NULL; +#endif +#endif /* CONFIG_SMP */ + memset(current->thread.fpr, 0, sizeof(current->thread.fpr)); + current->thread.fpscr = 0; +#ifdef CONFIG_ALTIVEC + memset(current->thread.vr, 0, sizeof(current->thread.vr)); + memset(¤t->thread.vscr, 0, sizeof(current->thread.vscr)); + current->thread.vrsave = 0; + current->thread.used_vr = 0; +#endif /* CONFIG_ALTIVEC */ +#ifdef CONFIG_SPE + memset(current->thread.evr, 0, sizeof(current->thread.evr)); + current->thread.acc = 0; + current->thread.spefscr = 0; + current->thread.used_spe = 0; +#endif /* CONFIG_SPE */ +} + +#define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \ + | PR_FP_EXC_RES | PR_FP_EXC_INV) + +int set_fpexc_mode(struct task_struct *tsk, unsigned int val) +{ + struct pt_regs *regs = tsk->thread.regs; + + /* This is a bit hairy. If we are an SPE enabled processor + * (have embedded fp) we store the IEEE exception enable flags in + * fpexc_mode. fpexc_mode is also used for setting FP exception + * mode (asyn, precise, disabled) for 'Classic' FP. */ + if (val & PR_FP_EXC_SW_ENABLE) { +#ifdef CONFIG_SPE + tsk->thread.fpexc_mode = val & + (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT); +#else + return -EINVAL; +#endif + } else { + /* on a CONFIG_SPE this does not hurt us. The bits that + * __pack_fe01 use do not overlap with bits used for + * PR_FP_EXC_SW_ENABLE. Additionally, the MSR[FE0,FE1] bits + * on CONFIG_SPE implementations are reserved so writing to + * them does not change anything */ + 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; + + if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) +#ifdef CONFIG_SPE + val = tsk->thread.fpexc_mode; +#else + return -EINVAL; +#endif + else + val = __unpack_fe01(tsk->thread.fpexc_mode); + return put_user(val, (unsigned int __user *) adr); +} + +int sys_clone(unsigned long clone_flags, unsigned long usp, + int __user *parent_tidp, void __user *child_threadptr, + int __user *child_tidp, int p6, + struct pt_regs *regs) +{ + CHECK_FULL_REGS(regs); + if (usp == 0) + usp = regs->gpr[1]; /* stack pointer for child */ + return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp); +} + +int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3, + unsigned long p4, unsigned long p5, unsigned long p6, + struct pt_regs *regs) +{ + CHECK_FULL_REGS(regs); + return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL); +} + +int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3, + unsigned long p4, unsigned long p5, unsigned long p6, + struct pt_regs *regs) +{ + CHECK_FULL_REGS(regs); + return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1], + regs, 0, NULL, NULL); +} + +int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2, + unsigned long a3, unsigned long a4, unsigned long a5, + struct pt_regs *regs) +{ + int error; + char * filename; + + filename = getname((char __user *) a0); + error = PTR_ERR(filename); + if (IS_ERR(filename)) + goto out; + flush_fp_to_thread(current); + flush_altivec_to_thread(current); + flush_spe_to_thread(current); + error = do_execve(filename, (char __user * __user *) a1, + (char __user * __user *) a2, regs); + if (error == 0) { + task_lock(current); + current->ptrace &= ~PT_DTRACE; + task_unlock(current); + } + putname(filename); +out: + return error; +} + +static int validate_sp(unsigned long sp, struct task_struct *p, + unsigned long nbytes) +{ + unsigned long stack_page = (unsigned long)p->thread_info; + + if (sp >= stack_page + sizeof(struct thread_struct) + && sp <= stack_page + THREAD_SIZE - nbytes) + return 1; + +#ifdef CONFIG_IRQSTACKS + stack_page = (unsigned long) hardirq_ctx[task_cpu(p)]; + if (sp >= stack_page + sizeof(struct thread_struct) + && sp <= stack_page + THREAD_SIZE - nbytes) + return 1; + + stack_page = (unsigned long) softirq_ctx[task_cpu(p)]; + if (sp >= stack_page + sizeof(struct thread_struct) + && sp <= stack_page + THREAD_SIZE - nbytes) + return 1; +#endif + + return 0; +} + +void dump_stack(void) +{ + show_stack(current, NULL); +} + +EXPORT_SYMBOL(dump_stack); + +void show_stack(struct task_struct *tsk, unsigned long *stack) +{ + unsigned long sp, stack_top, prev_sp, ret; + int count = 0; + unsigned long next_exc = 0; + struct pt_regs *regs; + extern char ret_from_except, ret_from_except_full, ret_from_syscall; + + sp = (unsigned long) stack; + if (tsk == NULL) + tsk = current; + if (sp == 0) { + if (tsk == current) + asm("mr %0,1" : "=r" (sp)); + else + sp = tsk->thread.ksp; + } + + prev_sp = (unsigned long) (tsk->thread_info + 1); + stack_top = (unsigned long) tsk->thread_info + THREAD_SIZE; + while (count < 16 && sp > prev_sp && sp < stack_top && (sp & 3) == 0) { + if (count == 0) { + printk("Call trace:"); +#ifdef CONFIG_KALLSYMS + printk("\n"); +#endif + } else { + if (next_exc) { + ret = next_exc; + next_exc = 0; + } else + ret = *(unsigned long *)(sp + 4); + printk(" [%08lx] ", ret); +#ifdef CONFIG_KALLSYMS + print_symbol("%s", ret); + printk("\n"); +#endif + if (ret == (unsigned long) &ret_from_except + || ret == (unsigned long) &ret_from_except_full + || ret == (unsigned long) &ret_from_syscall) { + /* sp + 16 points to an exception frame */ + regs = (struct pt_regs *) (sp + 16); + if (sp + 16 + sizeof(*regs) <= stack_top) + next_exc = regs->nip; + } + } + ++count; + sp = *(unsigned long *)sp; + } +#ifndef CONFIG_KALLSYMS + if (count > 0) + printk("\n"); +#endif +} + +unsigned long get_wchan(struct task_struct *p) +{ + unsigned long ip, sp; + int count = 0; + + if (!p || p == current || p->state == TASK_RUNNING) + return 0; + + sp = p->thread.ksp; + if (!validate_sp(sp, p, 16)) + return 0; + + do { + sp = *(unsigned long *)sp; + if (!validate_sp(sp, p, 16)) + return 0; + if (count > 0) { + ip = *(unsigned long *)(sp + 4); + if (!in_sched_functions(ip)) + return ip; + } + } while (count++ < 16); + return 0; +} +EXPORT_SYMBOL(get_wchan); |