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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/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/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 <linux/reboot.h>
#include <linux/tty.h>
#include <linux/console.h>
#include <asm/reg.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/hwrpb.h>
#include <asm/fpu.h>
#include "proto.h"
#include "pci_impl.h"
/*
* Initial task structure. Make this a per-architecture thing,
* because different architectures tend to have different
* alignment requirements and potentially different initial
* setup.
*/
unsigned long init_user_stack[1024] = { STACK_MAGIC, };
static struct fs_struct init_fs = INIT_FS;
static struct files_struct init_files = INIT_FILES;
static struct signal_struct init_signals = INIT_SIGNALS;
struct mm_struct init_mm = INIT_MM(init_mm);
union task_union init_task_union __attribute__((section("init_task")))
= { task: INIT_TASK(init_task_union.task) };
/*
* No need to acquire the kernel lock, we're entirely local..
*/
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)
{
(®s)->hae = hae;
return 0;
}
void
cpu_idle(void)
{
/* An endless idle loop with no priority at all. */
current->nice = 20;
current->counter = -100;
while (1) {
/* FIXME -- EV6 and LCA45 know how to power down
the CPU. */
/* Although we are an idle CPU, we do not want to
get into the scheduler unnecessarily. */
long oldval = xchg(¤t->need_resched, -1UL);
if (!oldval)
while (current->need_resched < 0);
schedule();
check_pgt_cache();
}
}
struct halt_info {
int mode;
char *restart_cmd;
};
static void
common_shutdown_1(void *generic_ptr)
{
struct halt_info *how = (struct halt_info *)generic_ptr;
struct percpu_struct *cpup;
unsigned long *pflags, flags;
int cpuid = smp_processor_id();
/* No point in taking interrupts anymore. */
__cli();
cpup = (struct percpu_struct *)
((unsigned long)hwrpb + hwrpb->processor_offset
+ hwrpb->processor_size * cpuid);
pflags = &cpup->flags;
flags = *pflags;
/* Clear reason to "default"; clear "bootstrap in progress". */
flags &= ~0x00ff0001UL;
#ifdef CONFIG_SMP
/* Secondaries halt here. */
if (cpuid != boot_cpuid) {
flags |= 0x00040000UL; /* "remain halted" */
*pflags = flags;
clear_bit(cpuid, &cpu_present_mask);
halt();
}
#endif
if (how->mode == LINUX_REBOOT_CMD_RESTART) {
if (!how->restart_cmd) {
flags |= 0x00020000UL; /* "cold bootstrap" */
} else {
/* For SRM, we could probably set environment
variables to get this to work. We'd have to
delay this until after srm_paging_stop unless
we ever got srm_fixup working.
At the moment, SRM will use the last boot device,
but the file and flags will be the defaults, when
doing a "warm" bootstrap. */
flags |= 0x00030000UL; /* "warm bootstrap" */
}
} else {
flags |= 0x00040000UL; /* "remain halted" */
}
*pflags = flags;
#ifdef CONFIG_SMP
/* Wait for the secondaries to halt. */
clear_bit(boot_cpuid, &cpu_present_mask);
while (cpu_present_mask)
barrier();
#endif
/* If booted from SRM, reset some of the original environment. */
if (alpha_using_srm) {
#ifdef CONFIG_DUMMY_CONSOLE
/* This has the effect of resetting the VGA video origin. */
take_over_console(&dummy_con, 0, MAX_NR_CONSOLES-1, 1);
#endif
/* reset_for_srm(); */
set_hae(srm_hae);
}
if (alpha_mv.kill_arch)
alpha_mv.kill_arch(how->mode);
if (! alpha_using_srm && how->mode != LINUX_REBOOT_CMD_RESTART) {
/* Unfortunately, since MILO doesn't currently understand
the hwrpb bits above, we can't reliably halt the
processor and keep it halted. So just loop. */
return;
}
if (alpha_using_srm)
srm_paging_stop();
halt();
}
static void
common_shutdown(int mode, char *restart_cmd)
{
struct halt_info args;
args.mode = mode;
args.restart_cmd = restart_cmd;
#ifdef CONFIG_SMP
smp_call_function(common_shutdown_1, &args, 1, 0);
#endif
common_shutdown_1(&args);
}
void
machine_restart(char *restart_cmd)
{
common_shutdown(LINUX_REBOOT_CMD_RESTART, restart_cmd);
}
void
machine_halt(void)
{
common_shutdown(LINUX_REBOOT_CMD_HALT, NULL);
}
void
machine_power_off(void)
{
common_shutdown(LINUX_REBOOT_CMD_POWER_OFF, NULL);
}
void
show_regs(struct pt_regs * regs)
{
printk("\n");
printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
printk("ps: %04lx pc: [<%016lx>] CPU %d %s\n",
regs->ps, regs->pc, smp_processor_id(), print_tainted());
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)
{
/* Arrange for each exec'ed process to start off with a clean slate
with respect to the FPU. This is all exceptions disabled. */
current->thread.flags &= ~IEEE_SW_MASK;
wrfpcr(FPCR_DYN_NORMAL | ieee_swcr_to_fpcr(0));
}
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), 0);
}
int
alpha_vfork(struct switch_stack * swstack)
{
return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(),
(struct pt_regs *) (swstack+1), 0);
}
/*
* 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().
*/
int
copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
unsigned long unused,
struct task_struct * p, struct pt_regs * regs)
{
extern void ret_from_sys_call(void);
extern void ret_from_fork(void);
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 *) (stack_offset + PAGE_SIZE + (long)p);
*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_fork;
p->thread.usp = usp;
p->thread.ksp = (unsigned long) childstack;
p->thread.pal_flags = 1; /* set FEN, clear everything else */
p->thread.flags = current->thread.flags;
return 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(char *ufilename, char **argv, char **envp,
unsigned long a3, unsigned long a4, unsigned long a5,
struct pt_regs regs)
{
int error;
char *filename;
filename = getname(ufilename);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename, argv, envp, ®s);
putname(filename);
out:
return error;
}
/*
* These bracket the sleeping functions..
*/
extern void scheduling_functions_start_here(void);
extern void scheduling_functions_end_here(void);
#define first_sched ((unsigned long) scheduling_functions_start_here)
#define last_sched ((unsigned long) scheduling_functions_end_here)
unsigned long
get_wchan(struct task_struct *p)
{
unsigned long schedule_frame;
unsigned long pc;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
/*
* This one depends on the frame size of schedule(). Do a
* "disass schedule" in gdb to find the frame size. Also, the
* code assumes that sleep_on() follows immediately after
* interruptible_sleep_on() and that add_timer() follows
* immediately after interruptible_sleep(). Ugly, isn't it?
* Maybe adding a wchan field to task_struct would be better,
* after all...
*/
pc = thread_saved_pc(&p->thread);
if (pc >= first_sched && pc < last_sched) {
schedule_frame = ((unsigned long *)p->thread.ksp)[6];
return ((unsigned long *)schedule_frame)[12];
}
return pc;
}
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