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/*

 *  linux/arch/alpha/kernel/process.c

 *

 *  Copyright (C) 1995  Linus Torvalds

 */

/*

 * This file handles the architecture-dependent parts of process handling..

 */

#include <linux/config.h>

#include <linux/errno.h>

#include <linux/sched.h>

#include <linux/kernel.h>

#include <linux/mm.h>

#include <linux/stddef.h>

#include <linux/unistd.h>

#include <linux/ptrace.h>

#include <linux/malloc.h>

#include <linux/ldt.h>

#include <linux/user.h>

#include <linux/a.out.h>

#include <linux/utsname.h>

#include <linux/time.h>

#include <linux/major.h>

#include <linux/stat.h>

#include <linux/mman.h>

#include <linux/elfcore.h>

#include <asm/reg.h>

#include <asm/segment.h>

#include <asm/system.h>

#include <asm/io.h>

asmlinkage int sys_sethae(unsigned long hae, unsigned long a1,

                          unsigned long a2, unsigned long a3,

                          unsigned long a4, unsigned long a5,

        struct pt_regs regs)

{

        (&regs)->hae = hae;

        return 0;

}

asmlinkage int sys_idle(void)

{

        if (current->pid != 0)

                return -EPERM;

        /* endless idle loop with no priority at all */

        current->counter = -100;

        for (;;) {

                schedule();

        }

}

#include <asm/hwrpb.h>

static void swap_context(struct thread_struct * pcb)

{

        __asm__ __volatile__(

                "bis %0,%0,$16\n\t"

                "call_pal %1\n\t"

                : /* no outputs */

                : "r" (pcb), "i" (PAL_swpctx)

                : "$0", "$1", "$16", "$22", "$23", "$24", "$25");

}

void hard_reset_now(void)

{

#if defined(CONFIG_ALPHA_SRM_SETUP)

        extern void reset_for_srm(void);

        extern struct hwrpb_struct *hwrpb;

        extern struct thread_struct *original_pcb_ptr;

        struct percpu_struct *cpup;

        unsigned long flags;

        cpup = (struct percpu_struct *)

          ((unsigned long)hwrpb + hwrpb->processor_offset);

        flags = cpup->flags;

#if 1

        printk("hard_reset_now: flags 0x%lx\n", flags);

#endif

        flags &= ~0x0000000000ff0001UL; /* clear reason to "default" */

        flags |=  0x0000000000020000UL; /* this is "cold bootstrap" */

/*      flags |=  0x0000000000030000UL; *//* this is "warm bootstrap" */

/*      flags |=  0x0000000000040000UL; *//* this is "remain halted" */

        cpup->flags = flags;

        mb();

        reset_for_srm();

        swap_context(original_pcb_ptr);

#endif

#if defined(CONFIG_ALPHA_SRM) && defined(CONFIG_ALPHA_ALCOR)

        /* who said DEC engineer's have no sense of humor? ;-)) */

        *(int *) GRU_RESET = 0x0000dead;

        mb();

#endif

        halt();

}

void show_regs(struct pt_regs * regs)

{

        printk("\nps: %04lx pc: [<%016lx>]\n", regs->ps, regs->pc);

        printk("rp: [<%016lx>] sp: %p\n", regs->r26, regs+1);

        printk(" r0: %016lx  r1: %016lx  r2: %016lx  r3: %016lx\n",

               regs->r0, regs->r1, regs->r2, regs->r3);

        printk(" r4: %016lx  r5: %016lx  r6: %016lx  r7: %016lx\n",

               regs->r4, regs->r5, regs->r6, regs->r7);

        printk(" r8: %016lx r16: %016lx r17: %016lx r18: %016lx\n",

               regs->r8, regs->r16, regs->r17, regs->r18);

        printk("r19: %016lx r20: %016lx r21: %016lx r22: %016lx\n",

               regs->r19, regs->r20, regs->r21, regs->r22);

        printk("r23: %016lx r24: %016lx r25: %016lx r26: %016lx\n",

               regs->r23, regs->r24, regs->r25, regs->r26);

        printk("r27: %016lx r28: %016lx r29: %016lx hae: %016lx\n",

               regs->r27, regs->r28, regs->gp, regs->hae);

}

/*

 * Re-start a thread when doing execve()

 */

void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)

{

        set_fs(USER_DS);

        regs->pc = pc;

        regs->ps = 8;

        wrusp(sp);

}

/*

 * Free current thread data structures etc..

 */

void exit_thread(void)

{

}

void flush_thread(void)

{

}

void release_thread(struct task_struct *dead_task)

{

}

/*

 * "alpha_clone()".. By the time we get here, the

 * non-volatile registers have also been saved on the

 * stack. We do some ugly pointer stuff here.. (see

 * also copy_thread)

 *

 * Notice that "fork()" is implemented in terms of clone,

 * with parameters (SIGCHLD, 0).

 */

int alpha_clone(unsigned long clone_flags, unsigned long usp,

        struct switch_stack * swstack)

{

        if (!usp)

                usp = rdusp();

        return do_fork(clone_flags, usp, (struct pt_regs *) (swstack+1));

}

extern void ret_from_sys_call(void);

/*

 * Copy an alpha thread..

 *

 * Note the "stack_offset" stuff: when returning to kernel mode, we need

 * to have some extra stack-space for the kernel stack that still exists

 * after the "ret_from_sys_call". When returning to user mode, we only

 * want the space needed by the syscall stack frame (ie "struct pt_regs").

 * Use the passed "regs" pointer to determine how much space we need

 * for a kernel fork().

 */

void copy_thread(int nr, unsigned long clone_flags, unsigned long usp,

        struct task_struct * p, struct pt_regs * regs)

{

        struct pt_regs * childregs;

        struct switch_stack * childstack, *stack;

        unsigned long stack_offset;

        stack_offset = PAGE_SIZE - sizeof(struct pt_regs);

        if (!(regs->ps & 8))

                stack_offset = (PAGE_SIZE-1) & (unsigned long) regs;

        childregs = (struct pt_regs *) (p->kernel_stack_page + stack_offset);

        *childregs = *regs;

        childregs->r0 = 0;

        childregs->r19 = 0;

        childregs->r20 = 1;     /* OSF/1 has some strange fork() semantics.. */

        regs->r20 = 0;

        stack = ((struct switch_stack *) regs) - 1;

        childstack = ((struct switch_stack *) childregs) - 1;

        *childstack = *stack;

        childstack->r26 = (unsigned long) ret_from_sys_call;

        p->tss.usp = usp;

        p->tss.ksp = (unsigned long) childstack;

        p->tss.pal_flags = 1;   /* set FEN, clear everything else */

        p->tss.flags = current->tss.flags;

        p->mm->context = 0;

}

/*

 * fill in the user structure for a core dump..

 */

void dump_thread(struct pt_regs * pt, struct user * dump)

{

        /* switch stack follows right below pt_regs: */

        struct switch_stack * sw = ((struct switch_stack *) pt) - 1;

        dump->magic = CMAGIC;

        dump->start_code  = current->mm->start_code;

        dump->start_data  = current->mm->start_data;

        dump->start_stack = rdusp() & ~(PAGE_SIZE - 1);

        dump->u_tsize = (current->mm->end_code - dump->start_code) >> PAGE_SHIFT;

        dump->u_dsize = (current->mm->brk + (PAGE_SIZE - 1) - dump->start_data) >> PAGE_SHIFT;

        dump->u_ssize =

          (current->mm->start_stack - dump->start_stack + PAGE_SIZE - 1) >> PAGE_SHIFT;

        /*

         * We store the registers in an order/format that is

         * compatible with DEC Unix/OSF/1 as this makes life easier

         * for gdb.

         */

        dump->regs[EF_V0]  = pt->r0;

        dump->regs[EF_T0]  = pt->r1;

        dump->regs[EF_T1]  = pt->r2;

        dump->regs[EF_T2]  = pt->r3;

        dump->regs[EF_T3]  = pt->r4;

        dump->regs[EF_T4]  = pt->r5;

        dump->regs[EF_T5]  = pt->r6;

        dump->regs[EF_T6]  = pt->r7;

        dump->regs[EF_T7]  = pt->r8;

        dump->regs[EF_S0]  = sw->r9;

        dump->regs[EF_S1]  = sw->r10;

        dump->regs[EF_S2]  = sw->r11;

        dump->regs[EF_S3]  = sw->r12;

        dump->regs[EF_S4]  = sw->r13;

        dump->regs[EF_S5]  = sw->r14;

        dump->regs[EF_S6]  = sw->r15;

        dump->regs[EF_A3]  = pt->r19;

        dump->regs[EF_A4]  = pt->r20;

        dump->regs[EF_A5]  = pt->r21;

        dump->regs[EF_T8]  = pt->r22;

        dump->regs[EF_T9]  = pt->r23;

        dump->regs[EF_T10] = pt->r24;

        dump->regs[EF_T11] = pt->r25;

        dump->regs[EF_RA]  = pt->r26;

        dump->regs[EF_T12] = pt->r27;

        dump->regs[EF_AT]  = pt->r28;

        dump->regs[EF_SP]  = rdusp();

        dump->regs[EF_PS]  = pt->ps;

        dump->regs[EF_PC]  = pt->pc;

        dump->regs[EF_GP]  = pt->gp;

        dump->regs[EF_A0]  = pt->r16;

        dump->regs[EF_A1]  = pt->r17;

        dump->regs[EF_A2]  = pt->r18;

        memcpy((char *)dump->regs + EF_SIZE, sw->fp, 32 * 8);

}

int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r)

{

        /* switch stack follows right below pt_regs: */

        struct switch_stack * sw = ((struct switch_stack *) regs) - 1;

        memcpy(r, sw->fp, 32 * 8);

        return 1;

}

/*

 * sys_execve() executes a new program.

 *

 * This works due to the alpha calling sequence: the first 6 args

 * are gotten from registers, while the rest is on the stack, so

 * we get a0-a5 for free, and then magically find "struct pt_regs"

 * on the stack for us..

 *

 * Don't do this at home.

 */

asmlinkage 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;

        error = getname((char *) a0, &filename);

        if (error)

                return error;

        error = do_execve(filename, (char **) a1, (char **) a2, &regs);

        putname(filename);

        return error;

}