| /* process.c: FRV specific parts of process handling |
| * |
| * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved. |
| * Written by David Howells (dhowells@redhat.com) |
| * - Derived from arch/m68k/kernel/process.c |
| * |
| * 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/module.h> |
| #include <linux/errno.h> |
| #include <linux/sched.h> |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/smp.h> |
| #include <linux/stddef.h> |
| #include <linux/unistd.h> |
| #include <linux/ptrace.h> |
| #include <linux/slab.h> |
| #include <linux/user.h> |
| #include <linux/elf.h> |
| #include <linux/reboot.h> |
| #include <linux/interrupt.h> |
| #include <linux/pagemap.h> |
| #include <linux/rcupdate.h> |
| |
| #include <asm/asm-offsets.h> |
| #include <asm/uaccess.h> |
| #include <asm/setup.h> |
| #include <asm/pgtable.h> |
| #include <asm/tlb.h> |
| #include <asm/gdb-stub.h> |
| #include <asm/mb-regs.h> |
| |
| #include "local.h" |
| |
| asmlinkage void ret_from_fork(void); |
| asmlinkage void ret_from_kernel_thread(void); |
| |
| #include <asm/pgalloc.h> |
| |
| void (*pm_power_off)(void); |
| EXPORT_SYMBOL(pm_power_off); |
| |
| static void core_sleep_idle(void) |
| { |
| #ifdef LED_DEBUG_SLEEP |
| /* Show that we're sleeping... */ |
| __set_LEDS(0x55aa); |
| #endif |
| frv_cpu_core_sleep(); |
| #ifdef LED_DEBUG_SLEEP |
| /* ... and that we woke up */ |
| __set_LEDS(0); |
| #endif |
| mb(); |
| } |
| |
| void (*idle)(void) = core_sleep_idle; |
| |
| /* |
| * The idle thread. There's no useful work to be |
| * done, so just try to conserve power and have a |
| * low exit latency (ie sit in a loop waiting for |
| * somebody to say that they'd like to reschedule) |
| */ |
| void cpu_idle(void) |
| { |
| /* endless idle loop with no priority at all */ |
| while (1) { |
| rcu_idle_enter(); |
| while (!need_resched()) { |
| check_pgt_cache(); |
| |
| if (!frv_dma_inprogress && idle) |
| idle(); |
| } |
| rcu_idle_exit(); |
| |
| schedule_preempt_disabled(); |
| } |
| } |
| |
| void machine_restart(char * __unused) |
| { |
| unsigned long reset_addr; |
| #ifdef CONFIG_GDBSTUB |
| gdbstub_exit(0); |
| #endif |
| |
| if (PSR_IMPLE(__get_PSR()) == PSR_IMPLE_FR551) |
| reset_addr = 0xfefff500; |
| else |
| reset_addr = 0xfeff0500; |
| |
| /* Software reset. */ |
| asm volatile(" dcef @(gr0,gr0),1 ! membar !" |
| " sti %1,@(%0,0) !" |
| " nop ! nop ! nop ! nop ! nop ! " |
| " nop ! nop ! nop ! nop ! nop ! " |
| " nop ! nop ! nop ! nop ! nop ! " |
| " nop ! nop ! nop ! nop ! nop ! " |
| : : "r" (reset_addr), "r" (1) ); |
| |
| for (;;) |
| ; |
| } |
| |
| void machine_halt(void) |
| { |
| #ifdef CONFIG_GDBSTUB |
| gdbstub_exit(0); |
| #endif |
| |
| for (;;); |
| } |
| |
| void machine_power_off(void) |
| { |
| #ifdef CONFIG_GDBSTUB |
| gdbstub_exit(0); |
| #endif |
| |
| for (;;); |
| } |
| |
| void flush_thread(void) |
| { |
| /* nothing */ |
| } |
| |
| inline unsigned long user_stack(const struct pt_regs *regs) |
| { |
| while (regs->next_frame) |
| regs = regs->next_frame; |
| return user_mode(regs) ? regs->sp : 0; |
| } |
| |
| asmlinkage int sys_fork(void) |
| { |
| #ifndef CONFIG_MMU |
| /* fork almost works, enough to trick you into looking elsewhere:-( */ |
| return -EINVAL; |
| #else |
| return do_fork(SIGCHLD, user_stack(__frame), __frame, 0, NULL, NULL); |
| #endif |
| } |
| |
| asmlinkage int sys_vfork(void) |
| { |
| return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, user_stack(__frame), __frame, 0, |
| NULL, NULL); |
| } |
| |
| /*****************************************************************************/ |
| /* |
| * clone a process |
| * - tlsptr is retrieved by copy_thread() |
| */ |
| asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp, |
| int __user *parent_tidptr, int __user *child_tidptr, |
| int __user *tlsptr) |
| { |
| if (!newsp) |
| newsp = user_stack(__frame); |
| return do_fork(clone_flags, newsp, __frame, 0, parent_tidptr, child_tidptr); |
| } /* end sys_clone() */ |
| |
| /* |
| * set up the kernel stack and exception frames for a new process |
| */ |
| int copy_thread(unsigned long clone_flags, |
| unsigned long usp, unsigned long arg, |
| struct task_struct *p, struct pt_regs *regs) |
| { |
| struct pt_regs *childregs; |
| |
| childregs = (struct pt_regs *) |
| (task_stack_page(p) + THREAD_SIZE - FRV_FRAME0_SIZE); |
| |
| p->set_child_tid = p->clear_child_tid = NULL; |
| |
| p->thread.frame = childregs; |
| p->thread.curr = p; |
| p->thread.sp = (unsigned long) childregs; |
| p->thread.fp = 0; |
| p->thread.lr = 0; |
| p->thread.frame0 = childregs; |
| |
| if (unlikely(!regs)) { |
| memset(childregs, 0, sizeof(struct pt_regs)); |
| childregs->gr9 = usp; /* function */ |
| childregs->gr8 = arg; |
| childregs->psr = PSR_S; |
| p->thread.pc = (unsigned long) ret_from_kernel_thread; |
| save_user_regs(p->thread.user); |
| return 0; |
| } |
| |
| /* set up the userspace frame (the only place that the USP is stored) */ |
| *childregs = *regs; |
| |
| childregs->sp = usp; |
| childregs->next_frame = NULL; |
| |
| p->thread.pc = (unsigned long) ret_from_fork; |
| |
| /* the new TLS pointer is passed in as arg #5 to sys_clone() */ |
| if (clone_flags & CLONE_SETTLS) |
| childregs->gr29 = childregs->gr12; |
| |
| save_user_regs(p->thread.user); |
| |
| return 0; |
| } /* end copy_thread() */ |
| |
| unsigned long get_wchan(struct task_struct *p) |
| { |
| struct pt_regs *regs0; |
| unsigned long fp, pc; |
| unsigned long stack_limit; |
| int count = 0; |
| if (!p || p == current || p->state == TASK_RUNNING) |
| return 0; |
| |
| stack_limit = (unsigned long) (p + 1); |
| fp = p->thread.fp; |
| regs0 = p->thread.frame0; |
| |
| do { |
| if (fp < stack_limit || fp >= (unsigned long) regs0 || fp & 3) |
| return 0; |
| |
| pc = ((unsigned long *) fp)[2]; |
| |
| /* FIXME: This depends on the order of these functions. */ |
| if (!in_sched_functions(pc)) |
| return pc; |
| |
| fp = *(unsigned long *) fp; |
| } while (count++ < 16); |
| |
| return 0; |
| } |
| |
| unsigned long thread_saved_pc(struct task_struct *tsk) |
| { |
| /* Check whether the thread is blocked in resume() */ |
| if (in_sched_functions(tsk->thread.pc)) |
| return ((unsigned long *)tsk->thread.fp)[2]; |
| else |
| return tsk->thread.pc; |
| } |
| |
| int elf_check_arch(const struct elf32_hdr *hdr) |
| { |
| unsigned long hsr0 = __get_HSR(0); |
| unsigned long psr = __get_PSR(); |
| |
| if (hdr->e_machine != EM_FRV) |
| return 0; |
| |
| switch (hdr->e_flags & EF_FRV_GPR_MASK) { |
| case EF_FRV_GPR64: |
| if ((hsr0 & HSR0_GRN) == HSR0_GRN_32) |
| return 0; |
| case EF_FRV_GPR32: |
| case 0: |
| break; |
| default: |
| return 0; |
| } |
| |
| switch (hdr->e_flags & EF_FRV_FPR_MASK) { |
| case EF_FRV_FPR64: |
| if ((hsr0 & HSR0_FRN) == HSR0_FRN_32) |
| return 0; |
| case EF_FRV_FPR32: |
| case EF_FRV_FPR_NONE: |
| case 0: |
| break; |
| default: |
| return 0; |
| } |
| |
| if ((hdr->e_flags & EF_FRV_MULADD) == EF_FRV_MULADD) |
| if (PSR_IMPLE(psr) != PSR_IMPLE_FR405 && |
| PSR_IMPLE(psr) != PSR_IMPLE_FR451) |
| return 0; |
| |
| switch (hdr->e_flags & EF_FRV_CPU_MASK) { |
| case EF_FRV_CPU_GENERIC: |
| break; |
| case EF_FRV_CPU_FR300: |
| case EF_FRV_CPU_SIMPLE: |
| case EF_FRV_CPU_TOMCAT: |
| default: |
| return 0; |
| case EF_FRV_CPU_FR400: |
| if (PSR_IMPLE(psr) != PSR_IMPLE_FR401 && |
| PSR_IMPLE(psr) != PSR_IMPLE_FR405 && |
| PSR_IMPLE(psr) != PSR_IMPLE_FR451 && |
| PSR_IMPLE(psr) != PSR_IMPLE_FR551) |
| return 0; |
| break; |
| case EF_FRV_CPU_FR450: |
| if (PSR_IMPLE(psr) != PSR_IMPLE_FR451) |
| return 0; |
| break; |
| case EF_FRV_CPU_FR500: |
| if (PSR_IMPLE(psr) != PSR_IMPLE_FR501) |
| return 0; |
| break; |
| case EF_FRV_CPU_FR550: |
| if (PSR_IMPLE(psr) != PSR_IMPLE_FR551) |
| return 0; |
| break; |
| } |
| |
| return 1; |
| } |
| |
| int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs) |
| { |
| memcpy(fpregs, |
| ¤t->thread.user->f, |
| sizeof(current->thread.user->f)); |
| return 1; |
| } |