| /* |
| * arch/sh/kernel/process.c |
| * |
| * This file handles the architecture-dependent parts of process handling.. |
| * |
| * Copyright (C) 1995 Linus Torvalds |
| * |
| * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima |
| * Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC |
| * Copyright (C) 2002 - 2007 Paul Mundt |
| */ |
| #include <linux/module.h> |
| #include <linux/mm.h> |
| #include <linux/elfcore.h> |
| #include <linux/pm.h> |
| #include <linux/kallsyms.h> |
| #include <linux/kexec.h> |
| #include <linux/kdebug.h> |
| #include <linux/tick.h> |
| #include <linux/reboot.h> |
| #include <asm/uaccess.h> |
| #include <asm/mmu_context.h> |
| #include <asm/pgalloc.h> |
| #include <asm/system.h> |
| #include <asm/ubc.h> |
| |
| static int hlt_counter; |
| int ubc_usercnt = 0; |
| |
| void (*pm_idle)(void); |
| void (*pm_power_off)(void); |
| EXPORT_SYMBOL(pm_power_off); |
| |
| void disable_hlt(void) |
| { |
| hlt_counter++; |
| } |
| EXPORT_SYMBOL(disable_hlt); |
| |
| void enable_hlt(void) |
| { |
| hlt_counter--; |
| } |
| EXPORT_SYMBOL(enable_hlt); |
| |
| static int __init nohlt_setup(char *__unused) |
| { |
| hlt_counter = 1; |
| return 1; |
| } |
| __setup("nohlt", nohlt_setup); |
| |
| static int __init hlt_setup(char *__unused) |
| { |
| hlt_counter = 0; |
| return 1; |
| } |
| __setup("hlt", hlt_setup); |
| |
| void default_idle(void) |
| { |
| if (!hlt_counter) { |
| clear_thread_flag(TIF_POLLING_NRFLAG); |
| smp_mb__after_clear_bit(); |
| set_bl_bit(); |
| while (!need_resched()) |
| cpu_sleep(); |
| clear_bl_bit(); |
| set_thread_flag(TIF_POLLING_NRFLAG); |
| } else |
| while (!need_resched()) |
| cpu_relax(); |
| } |
| |
| void cpu_idle(void) |
| { |
| set_thread_flag(TIF_POLLING_NRFLAG); |
| |
| /* endless idle loop with no priority at all */ |
| while (1) { |
| void (*idle)(void) = pm_idle; |
| |
| if (!idle) |
| idle = default_idle; |
| |
| tick_nohz_stop_sched_tick(); |
| while (!need_resched()) |
| idle(); |
| tick_nohz_restart_sched_tick(); |
| |
| preempt_enable_no_resched(); |
| schedule(); |
| preempt_disable(); |
| check_pgt_cache(); |
| } |
| } |
| |
| void machine_restart(char * __unused) |
| { |
| /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */ |
| asm volatile("ldc %0, sr\n\t" |
| "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001)); |
| } |
| |
| void machine_halt(void) |
| { |
| local_irq_disable(); |
| |
| while (1) |
| cpu_sleep(); |
| } |
| |
| void machine_power_off(void) |
| { |
| if (pm_power_off) |
| pm_power_off(); |
| } |
| |
| void show_regs(struct pt_regs * regs) |
| { |
| printk("\n"); |
| printk("Pid : %d, Comm: %20s\n", current->pid, current->comm); |
| print_symbol("PC is at %s\n", instruction_pointer(regs)); |
| printk("PC : %08lx SP : %08lx SR : %08lx ", |
| regs->pc, regs->regs[15], regs->sr); |
| #ifdef CONFIG_MMU |
| printk("TEA : %08x ", ctrl_inl(MMU_TEA)); |
| #else |
| printk(" "); |
| #endif |
| printk("%s\n", print_tainted()); |
| |
| printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n", |
| regs->regs[0],regs->regs[1], |
| regs->regs[2],regs->regs[3]); |
| printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n", |
| regs->regs[4],regs->regs[5], |
| regs->regs[6],regs->regs[7]); |
| printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n", |
| regs->regs[8],regs->regs[9], |
| regs->regs[10],regs->regs[11]); |
| printk("R12 : %08lx R13 : %08lx R14 : %08lx\n", |
| regs->regs[12],regs->regs[13], |
| regs->regs[14]); |
| printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n", |
| regs->mach, regs->macl, regs->gbr, regs->pr); |
| |
| show_trace(NULL, (unsigned long *)regs->regs[15], regs); |
| } |
| |
| /* |
| * Create a kernel thread |
| */ |
| |
| /* |
| * This is the mechanism for creating a new kernel thread. |
| * |
| */ |
| extern void kernel_thread_helper(void); |
| __asm__(".align 5\n" |
| "kernel_thread_helper:\n\t" |
| "jsr @r5\n\t" |
| " nop\n\t" |
| "mov.l 1f, r1\n\t" |
| "jsr @r1\n\t" |
| " mov r0, r4\n\t" |
| ".align 2\n\t" |
| "1:.long do_exit"); |
| |
| /* Don't use this in BL=1(cli). Or else, CPU resets! */ |
| int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) |
| { |
| struct pt_regs regs; |
| |
| memset(®s, 0, sizeof(regs)); |
| regs.regs[4] = (unsigned long)arg; |
| regs.regs[5] = (unsigned long)fn; |
| |
| regs.pc = (unsigned long)kernel_thread_helper; |
| regs.sr = (1 << 30); |
| |
| /* Ok, create the new process.. */ |
| return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, |
| ®s, 0, NULL, NULL); |
| } |
| |
| /* |
| * Free current thread data structures etc.. |
| */ |
| void exit_thread(void) |
| { |
| if (current->thread.ubc_pc) { |
| current->thread.ubc_pc = 0; |
| ubc_usercnt -= 1; |
| } |
| } |
| |
| void flush_thread(void) |
| { |
| #if defined(CONFIG_SH_FPU) |
| struct task_struct *tsk = current; |
| /* Forget lazy FPU state */ |
| clear_fpu(tsk, task_pt_regs(tsk)); |
| clear_used_math(); |
| #endif |
| } |
| |
| void release_thread(struct task_struct *dead_task) |
| { |
| /* do nothing */ |
| } |
| |
| /* Fill in the fpu structure for a core dump.. */ |
| int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu) |
| { |
| int fpvalid = 0; |
| |
| #if defined(CONFIG_SH_FPU) |
| struct task_struct *tsk = current; |
| |
| fpvalid = !!tsk_used_math(tsk); |
| if (fpvalid) { |
| unlazy_fpu(tsk, regs); |
| memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu)); |
| } |
| #endif |
| |
| return fpvalid; |
| } |
| |
| /* |
| * Capture the user space registers if the task is not running (in user space) |
| */ |
| int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs) |
| { |
| struct pt_regs ptregs; |
| |
| ptregs = *task_pt_regs(tsk); |
| elf_core_copy_regs(regs, &ptregs); |
| |
| return 1; |
| } |
| |
| int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpu) |
| { |
| int fpvalid = 0; |
| |
| #if defined(CONFIG_SH_FPU) |
| fpvalid = !!tsk_used_math(tsk); |
| if (fpvalid) { |
| unlazy_fpu(tsk, task_pt_regs(tsk)); |
| memcpy(fpu, &tsk->thread.fpu.hard, sizeof(*fpu)); |
| } |
| #endif |
| |
| return fpvalid; |
| } |
| |
| asmlinkage void ret_from_fork(void); |
| |
| int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, |
| unsigned long unused, |
| struct task_struct *p, struct pt_regs *regs) |
| { |
| struct thread_info *ti = task_thread_info(p); |
| struct pt_regs *childregs; |
| #if defined(CONFIG_SH_FPU) |
| struct task_struct *tsk = current; |
| |
| unlazy_fpu(tsk, regs); |
| p->thread.fpu = tsk->thread.fpu; |
| copy_to_stopped_child_used_math(p); |
| #endif |
| |
| childregs = task_pt_regs(p); |
| *childregs = *regs; |
| |
| if (user_mode(regs)) { |
| childregs->regs[15] = usp; |
| ti->addr_limit = USER_DS; |
| } else { |
| childregs->regs[15] = (unsigned long)childregs; |
| ti->addr_limit = KERNEL_DS; |
| } |
| |
| if (clone_flags & CLONE_SETTLS) |
| childregs->gbr = childregs->regs[0]; |
| |
| childregs->regs[0] = 0; /* Set return value for child */ |
| |
| p->thread.sp = (unsigned long) childregs; |
| p->thread.pc = (unsigned long) ret_from_fork; |
| |
| p->thread.ubc_pc = 0; |
| |
| return 0; |
| } |
| |
| /* Tracing by user break controller. */ |
| static void ubc_set_tracing(int asid, unsigned long pc) |
| { |
| #if defined(CONFIG_CPU_SH4A) |
| unsigned long val; |
| |
| val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE); |
| val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid)); |
| |
| ctrl_outl(val, UBC_CBR0); |
| ctrl_outl(pc, UBC_CAR0); |
| ctrl_outl(0x0, UBC_CAMR0); |
| ctrl_outl(0x0, UBC_CBCR); |
| |
| val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE); |
| ctrl_outl(val, UBC_CRR0); |
| |
| /* Read UBC register that we wrote last, for checking update */ |
| val = ctrl_inl(UBC_CRR0); |
| |
| #else /* CONFIG_CPU_SH4A */ |
| ctrl_outl(pc, UBC_BARA); |
| |
| #ifdef CONFIG_MMU |
| /* We don't have any ASID settings for the SH-2! */ |
| if (current_cpu_data.type != CPU_SH7604) |
| ctrl_outb(asid, UBC_BASRA); |
| #endif |
| |
| ctrl_outl(0, UBC_BAMRA); |
| |
| if (current_cpu_data.type == CPU_SH7729 || |
| current_cpu_data.type == CPU_SH7710 || |
| current_cpu_data.type == CPU_SH7712) { |
| ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA); |
| ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR); |
| } else { |
| ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA); |
| ctrl_outw(BRCR_PCBA, UBC_BRCR); |
| } |
| #endif /* CONFIG_CPU_SH4A */ |
| } |
| |
| /* |
| * switch_to(x,y) should switch tasks from x to y. |
| * |
| */ |
| struct task_struct *__switch_to(struct task_struct *prev, |
| struct task_struct *next) |
| { |
| #if defined(CONFIG_SH_FPU) |
| unlazy_fpu(prev, task_pt_regs(prev)); |
| #endif |
| |
| #ifdef CONFIG_PREEMPT |
| { |
| unsigned long flags; |
| struct pt_regs *regs; |
| |
| local_irq_save(flags); |
| regs = task_pt_regs(prev); |
| if (user_mode(regs) && regs->regs[15] >= 0xc0000000) { |
| int offset = (int)regs->regs[15]; |
| |
| /* Reset stack pointer: clear critical region mark */ |
| regs->regs[15] = regs->regs[1]; |
| if (regs->pc < regs->regs[0]) |
| /* Go to rewind point */ |
| regs->pc = regs->regs[0] + offset; |
| } |
| local_irq_restore(flags); |
| } |
| #endif |
| |
| #ifdef CONFIG_MMU |
| /* |
| * Restore the kernel mode register |
| * k7 (r7_bank1) |
| */ |
| asm volatile("ldc %0, r7_bank" |
| : /* no output */ |
| : "r" (task_thread_info(next))); |
| #endif |
| |
| /* If no tasks are using the UBC, we're done */ |
| if (ubc_usercnt == 0) |
| /* If no tasks are using the UBC, we're done */; |
| else if (next->thread.ubc_pc && next->mm) { |
| int asid = 0; |
| #ifdef CONFIG_MMU |
| asid |= cpu_asid(smp_processor_id(), next->mm); |
| #endif |
| ubc_set_tracing(asid, next->thread.ubc_pc); |
| } else { |
| #if defined(CONFIG_CPU_SH4A) |
| ctrl_outl(UBC_CBR_INIT, UBC_CBR0); |
| ctrl_outl(UBC_CRR_INIT, UBC_CRR0); |
| #else |
| ctrl_outw(0, UBC_BBRA); |
| ctrl_outw(0, UBC_BBRB); |
| #endif |
| } |
| |
| return prev; |
| } |
| |
| asmlinkage int sys_fork(unsigned long r4, unsigned long r5, |
| unsigned long r6, unsigned long r7, |
| struct pt_regs __regs) |
| { |
| struct pt_regs *regs = RELOC_HIDE(&__regs, 0); |
| #ifdef CONFIG_MMU |
| return do_fork(SIGCHLD, regs->regs[15], regs, 0, NULL, NULL); |
| #else |
| /* fork almost works, enough to trick you into looking elsewhere :-( */ |
| return -EINVAL; |
| #endif |
| } |
| |
| asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp, |
| unsigned long parent_tidptr, |
| unsigned long child_tidptr, |
| struct pt_regs __regs) |
| { |
| struct pt_regs *regs = RELOC_HIDE(&__regs, 0); |
| if (!newsp) |
| newsp = regs->regs[15]; |
| return do_fork(clone_flags, newsp, regs, 0, |
| (int __user *)parent_tidptr, |
| (int __user *)child_tidptr); |
| } |
| |
| /* |
| * This is trivial, and on the face of it looks like it |
| * could equally well be done in user mode. |
| * |
| * Not so, for quite unobvious reasons - register pressure. |
| * In user mode vfork() cannot have a stack frame, and if |
| * done by calling the "clone()" system call directly, you |
| * do not have enough call-clobbered registers to hold all |
| * the information you need. |
| */ |
| asmlinkage int sys_vfork(unsigned long r4, unsigned long r5, |
| unsigned long r6, unsigned long r7, |
| struct pt_regs __regs) |
| { |
| struct pt_regs *regs = RELOC_HIDE(&__regs, 0); |
| return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->regs[15], regs, |
| 0, NULL, NULL); |
| } |
| |
| /* |
| * sys_execve() executes a new program. |
| */ |
| asmlinkage int sys_execve(char __user *ufilename, char __user * __user *uargv, |
| char __user * __user *uenvp, unsigned long r7, |
| struct pt_regs __regs) |
| { |
| struct pt_regs *regs = RELOC_HIDE(&__regs, 0); |
| int error; |
| char *filename; |
| |
| filename = getname(ufilename); |
| error = PTR_ERR(filename); |
| if (IS_ERR(filename)) |
| goto out; |
| |
| error = do_execve(filename, uargv, uenvp, regs); |
| if (error == 0) { |
| task_lock(current); |
| current->ptrace &= ~PT_DTRACE; |
| task_unlock(current); |
| } |
| putname(filename); |
| out: |
| return error; |
| } |
| |
| 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; |
| |
| /* |
| * The same comment as on the Alpha applies here, too ... |
| */ |
| pc = thread_saved_pc(p); |
| if (in_sched_functions(pc)) { |
| schedule_frame = (unsigned long)p->thread.sp; |
| return ((unsigned long *)schedule_frame)[21]; |
| } |
| |
| return pc; |
| } |
| |
| asmlinkage void break_point_trap(void) |
| { |
| /* Clear tracing. */ |
| #if defined(CONFIG_CPU_SH4A) |
| ctrl_outl(UBC_CBR_INIT, UBC_CBR0); |
| ctrl_outl(UBC_CRR_INIT, UBC_CRR0); |
| #else |
| ctrl_outw(0, UBC_BBRA); |
| ctrl_outw(0, UBC_BBRB); |
| #endif |
| current->thread.ubc_pc = 0; |
| ubc_usercnt -= 1; |
| |
| force_sig(SIGTRAP, current); |
| } |
| |
| /* |
| * Generic trap handler. |
| */ |
| asmlinkage void debug_trap_handler(unsigned long r4, unsigned long r5, |
| unsigned long r6, unsigned long r7, |
| struct pt_regs __regs) |
| { |
| struct pt_regs *regs = RELOC_HIDE(&__regs, 0); |
| |
| /* Rewind */ |
| regs->pc -= instruction_size(ctrl_inw(regs->pc - 4)); |
| |
| if (notify_die(DIE_TRAP, "debug trap", regs, 0, regs->tra & 0xff, |
| SIGTRAP) == NOTIFY_STOP) |
| return; |
| |
| force_sig(SIGTRAP, current); |
| } |
| |
| /* |
| * Special handler for BUG() traps. |
| */ |
| asmlinkage void bug_trap_handler(unsigned long r4, unsigned long r5, |
| unsigned long r6, unsigned long r7, |
| struct pt_regs __regs) |
| { |
| struct pt_regs *regs = RELOC_HIDE(&__regs, 0); |
| |
| /* Rewind */ |
| regs->pc -= instruction_size(ctrl_inw(regs->pc - 4)); |
| |
| if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff, |
| SIGTRAP) == NOTIFY_STOP) |
| return; |
| |
| #ifdef CONFIG_BUG |
| if (__kernel_text_address(instruction_pointer(regs))) { |
| u16 insn = *(u16 *)instruction_pointer(regs); |
| if (insn == TRAPA_BUG_OPCODE) |
| handle_BUG(regs); |
| } |
| #endif |
| |
| force_sig(SIGTRAP, current); |
| } |