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 000000000000..8b0686122738
--- /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);