| /* |
| * linux/arch/alpha/kernel/process.c |
| * |
| * Copyright (C) 1995 Linus Torvalds |
| */ |
| |
| /* |
| * This file handles the architecture-dependent parts of process handling. |
| */ |
| |
| #include <linux/errno.h> |
| #include <linux/module.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/vt.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" |
| |
| /* |
| * Power off function, if any |
| */ |
| void (*pm_power_off)(void) = machine_power_off; |
| EXPORT_SYMBOL(pm_power_off); |
| |
| void |
| cpu_idle(void) |
| { |
| set_thread_flag(TIF_POLLING_NRFLAG); |
| |
| while (1) { |
| /* FIXME -- EV6 and LCA45 know how to power down |
| the CPU. */ |
| |
| while (!need_resched()) |
| cpu_relax(); |
| schedule(); |
| } |
| } |
| |
| |
| 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. */ |
| local_irq_disable(); |
| |
| 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; |
| cpu_clear(cpuid, cpu_present_map); |
| 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. */ |
| cpu_clear(boot_cpuid, cpu_present_map); |
| while (cpus_weight(cpu_present_map)) |
| barrier(); |
| #endif |
| |
| /* If booted from SRM, reset some of the original environment. */ |
| if (alpha_using_srm) { |
| #ifdef CONFIG_DUMMY_CONSOLE |
| /* If we've gotten here after SysRq-b, leave interrupt |
| context before taking over the console. */ |
| if (in_interrupt()) |
| irq_exit(); |
| /* This has the effect of resetting the VGA video origin. */ |
| take_over_console(&dummy_con, 0, MAX_NR_CONSOLES-1, 1); |
| #endif |
| pci_restore_srm_config(); |
| 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; |
| on_each_cpu(common_shutdown_1, &args, 1, 0); |
| } |
| |
| 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); |
| } |
| |
| |
| /* Used by sysrq-p, among others. I don't believe r9-r15 are ever |
| saved in the context it's used. */ |
| |
| void |
| show_regs(struct pt_regs *regs) |
| { |
| dik_show_regs(regs, NULL); |
| } |
| |
| /* |
| * 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); |
| } |
| EXPORT_SYMBOL(start_thread); |
| |
| /* |
| * 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_info()->ieee_state = 0; |
| wrfpcr(FPCR_DYN_NORMAL | ieee_swcr_to_fpcr(0)); |
| |
| /* Clean slate for TLS. */ |
| current_thread_info()->pcb.unique = 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, |
| int __user *parent_tid, int __user *child_tid, |
| unsigned long tls_value, struct pt_regs *regs) |
| { |
| if (!usp) |
| usp = rdusp(); |
| |
| return do_fork(clone_flags, usp, regs, 0, parent_tid, child_tid); |
| } |
| |
| int |
| alpha_vfork(struct pt_regs *regs) |
| { |
| return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), |
| regs, 0, NULL, NULL); |
| } |
| |
| /* |
| * 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_fork". 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_fork(void); |
| |
| struct thread_info *childti = task_thread_info(p); |
| struct pt_regs * childregs; |
| struct switch_stack * childstack, *stack; |
| unsigned long stack_offset, settls; |
| |
| 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 + task_stack_page(p)); |
| |
| *childregs = *regs; |
| settls = regs->r20; |
| 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; |
| childti->pcb.usp = usp; |
| childti->pcb.ksp = (unsigned long) childstack; |
| childti->pcb.flags = 1; /* set FEN, clear everything else */ |
| |
| /* Set a new TLS for the child thread? Peek back into the |
| syscall arguments that we saved on syscall entry. Oops, |
| except we'd have clobbered it with the parent/child set |
| of r20. Read the saved copy. */ |
| /* Note: if CLONE_SETTLS is not set, then we must inherit the |
| value from the parent, which will have been set by the block |
| copy in dup_task_struct. This is non-intuitive, but is |
| required for proper operation in the case of a threaded |
| application calling fork. */ |
| if (clone_flags & CLONE_SETTLS) |
| childti->pcb.unique = settls; |
| |
| return 0; |
| } |
| |
| /* |
| * Fill in the user structure for an ECOFF 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); |
| } |
| EXPORT_SYMBOL(dump_thread); |
| |
| /* |
| * Fill in the user structure for a ELF core dump. |
| */ |
| void |
| dump_elf_thread(elf_greg_t *dest, struct pt_regs *pt, struct thread_info *ti) |
| { |
| /* switch stack follows right below pt_regs: */ |
| struct switch_stack * sw = ((struct switch_stack *) pt) - 1; |
| |
| dest[ 0] = pt->r0; |
| dest[ 1] = pt->r1; |
| dest[ 2] = pt->r2; |
| dest[ 3] = pt->r3; |
| dest[ 4] = pt->r4; |
| dest[ 5] = pt->r5; |
| dest[ 6] = pt->r6; |
| dest[ 7] = pt->r7; |
| dest[ 8] = pt->r8; |
| dest[ 9] = sw->r9; |
| dest[10] = sw->r10; |
| dest[11] = sw->r11; |
| dest[12] = sw->r12; |
| dest[13] = sw->r13; |
| dest[14] = sw->r14; |
| dest[15] = sw->r15; |
| dest[16] = pt->r16; |
| dest[17] = pt->r17; |
| dest[18] = pt->r18; |
| dest[19] = pt->r19; |
| dest[20] = pt->r20; |
| dest[21] = pt->r21; |
| dest[22] = pt->r22; |
| dest[23] = pt->r23; |
| dest[24] = pt->r24; |
| dest[25] = pt->r25; |
| dest[26] = pt->r26; |
| dest[27] = pt->r27; |
| dest[28] = pt->r28; |
| dest[29] = pt->gp; |
| dest[30] = rdusp(); |
| dest[31] = pt->pc; |
| |
| /* Once upon a time this was the PS value. Which is stupid |
| since that is always 8 for usermode. Usurped for the more |
| useful value of the thread's UNIQUE field. */ |
| dest[32] = ti->pcb.unique; |
| } |
| EXPORT_SYMBOL(dump_elf_thread); |
| |
| int |
| dump_elf_task(elf_greg_t *dest, struct task_struct *task) |
| { |
| dump_elf_thread(dest, task_pt_regs(task), task_thread_info(task)); |
| return 1; |
| } |
| EXPORT_SYMBOL(dump_elf_task); |
| |
| int |
| dump_elf_task_fp(elf_fpreg_t *dest, struct task_struct *task) |
| { |
| struct switch_stack *sw = (struct switch_stack *)task_pt_regs(task) - 1; |
| memcpy(dest, sw->fp, 32 * 8); |
| return 1; |
| } |
| EXPORT_SYMBOL(dump_elf_task_fp); |
| |
| /* |
| * sys_execve() executes a new program. |
| */ |
| asmlinkage int |
| do_sys_execve(char __user *ufilename, char __user * __user *argv, |
| char __user * __user *envp, 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, regs); |
| putname(filename); |
| out: |
| return error; |
| } |
| |
| /* |
| * Return saved PC of a blocked thread. This assumes the frame |
| * pointer is the 6th saved long on the kernel stack and that the |
| * saved return address is the first long in the frame. This all |
| * holds provided the thread blocked through a call to schedule() ($15 |
| * is the frame pointer in schedule() and $15 is saved at offset 48 by |
| * entry.S:do_switch_stack). |
| * |
| * Under heavy swap load I've seen this lose in an ugly way. So do |
| * some extra sanity checking on the ranges we expect these pointers |
| * to be in so that we can fail gracefully. This is just for ps after |
| * all. -- r~ |
| */ |
| |
| unsigned long |
| thread_saved_pc(struct task_struct *t) |
| { |
| unsigned long base = (unsigned long)task_stack_page(t); |
| unsigned long fp, sp = task_thread_info(t)->pcb.ksp; |
| |
| if (sp > base && sp+6*8 < base + 16*1024) { |
| fp = ((unsigned long*)sp)[6]; |
| if (fp > sp && fp < base + 16*1024) |
| return *(unsigned long *)fp; |
| } |
| |
| return 0; |
| } |
| |
| 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); |
| if (in_sched_functions(pc)) { |
| schedule_frame = ((unsigned long *)task_thread_info(p)->pcb.ksp)[6]; |
| return ((unsigned long *)schedule_frame)[12]; |
| } |
| return pc; |
| } |