summaryrefslogtreecommitdiffstats
path: root/arch/ppc64/kernel/process.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/ppc64/kernel/process.c')
-rw-r--r--arch/ppc64/kernel/process.c688
1 files changed, 688 insertions, 0 deletions
diff --git a/arch/ppc64/kernel/process.c b/arch/ppc64/kernel/process.c
new file mode 100644
index 00000000000..8b068612273
--- /dev/null
+++ b/arch/ppc64/kernel/process.c
@@ -0,0 +1,688 @@
+/*
+ * 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 <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
+
+struct mm_struct ioremap_mm = {
+ .pgd = ioremap_dir,
+ .mm_users = ATOMIC_INIT(2),
+ .mm_count = ATOMIC_INIT(1),
+ .cpu_vm_mask = CPU_MASK_ALL,
+ .page_table_lock = SPIN_LOCK_UNLOCKED,
+};
+
+/*
+ * 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, &current->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 = &current->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)
+{
+#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();
+
+ 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);
+#ifdef CONFIG_PPC_ISERIES
+ set_ti_thread_flag(p->thread_info, TIF_RUN_LIGHT);
+#endif
+ } 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;
+
+ val = __unpack_fe01(tsk->thread.fpexc_mode);
+ return put_user(val, (unsigned int __user *) adr);
+}
+
+int sys_clone(unsigned long clone_flags, unsigned long p2, unsigned long p3,
+ unsigned long p4, unsigned long p5, unsigned long p6,
+ struct pt_regs *regs)
+{
+ unsigned long parent_tidptr = 0;
+ unsigned long child_tidptr = 0;
+
+ if (p2 == 0)
+ p2 = regs->gpr[1]; /* stack pointer for child */
+
+ if (clone_flags & (CLONE_PARENT_SETTID | CLONE_CHILD_SETTID |
+ CLONE_CHILD_CLEARTID)) {
+ parent_tidptr = p3;
+ child_tidptr = p5;
+ if (test_thread_flag(TIF_32BIT)) {
+ parent_tidptr &= 0xffffffff;
+ child_tidptr &= 0xffffffff;
+ }
+ }
+
+ return do_fork(clone_flags, p2, regs, 0,
+ (int __user *)parent_tidptr, (int __user *)child_tidptr);
+}
+
+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)
+{
+ 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)
+{
+ 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);
+ 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 kstack_depth_to_print = 64;
+
+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;
+}
+
+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, 112))
+ return 0;
+
+ do {
+ sp = *(unsigned long *)sp;
+ if (!validate_sp(sp, p, 112))
+ return 0;
+ if (count > 0) {
+ ip = *(unsigned long *)(sp + 16);
+ if (!in_sched_functions(ip))
+ return ip;
+ }
+ } while (count++ < 16);
+ return 0;
+}
+EXPORT_SYMBOL(get_wchan);
+
+void show_stack(struct task_struct *p, unsigned long *_sp)
+{
+ unsigned long ip, newsp, lr;
+ int count = 0;
+ unsigned long sp = (unsigned long)_sp;
+ int firstframe = 1;
+
+ if (sp == 0) {
+ if (p) {
+ sp = p->thread.ksp;
+ } else {
+ sp = __get_SP();
+ p = current;
+ }
+ }
+
+ lr = 0;
+ printk("Call Trace:\n");
+ do {
+ if (!validate_sp(sp, p, 112))
+ return;
+
+ _sp = (unsigned long *) sp;
+ newsp = _sp[0];
+ ip = _sp[2];
+ if (!firstframe || ip != lr) {
+ printk("[%016lx] [%016lx] ", sp, ip);
+ print_symbol("%s", ip);
+ if (firstframe)
+ printk(" (unreliable)");
+ printk("\n");
+ }
+ firstframe = 0;
+
+ /*
+ * See if this is an exception frame.
+ * We look for the "regshere" marker in the current frame.
+ */
+ if (validate_sp(sp, p, sizeof(struct pt_regs) + 400)
+ && _sp[12] == 0x7265677368657265ul) {
+ struct pt_regs *regs = (struct pt_regs *)
+ (sp + STACK_FRAME_OVERHEAD);
+ printk("--- Exception: %lx", regs->trap);
+ print_symbol(" at %s\n", regs->nip);
+ lr = regs->link;
+ print_symbol(" LR = %s\n", lr);
+ firstframe = 1;
+ }
+
+ sp = newsp;
+ } while (count++ < kstack_depth_to_print);
+}
+
+void dump_stack(void)
+{
+ show_stack(current, (unsigned long *)__get_SP());
+}
+EXPORT_SYMBOL(dump_stack);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-26 15:23:29 +0000