Something went wrong. Try again.
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Something went wrong. Try again.
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289// SPDX-License-Identifier: GPL-2.0-or-later/* * OpenRISC process.c * * Linux architectural port borrowing liberally from similar works of * others. All original copyrights apply as per the original source * declaration. * * Modifications for the OpenRISC architecture: * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> * * This file handles the architecture-dependent parts of process handling... */
#define __KERNEL_SYSCALLS__#include <linux/cpu.h>#include <linux/errno.h>#include <linux/sched.h>#include <linux/sched/debug.h>#include <linux/sched/task.h>#include <linux/sched/task_stack.h>#include <linux/kernel.h>#include <linux/export.h>#include <linux/mm.h>#include <linux/stddef.h>#include <linux/unistd.h>#include <linux/ptrace.h>#include <linux/slab.h>#include <linux/elfcore.h>#include <linux/interrupt.h>#include <linux/delay.h>#include <linux/init_task.h>#include <linux/mqueue.h>#include <linux/fs.h>#include <linux/reboot.h>
#include <linux/uaccess.h>#include <asm/fpu.h>#include <asm/io.h>#include <asm/processor.h>#include <asm/spr_defs.h>#include <asm/switch_to.h>
#include <linux/smp.h>
/* * Pointer to Current thread info structure. * * Used at user space -> kernel transitions. */struct thread_info *current_thread_info_set[NR_CPUS] = { &init_thread_info, };
void machine_restart(char *cmd){ do_kernel_restart(cmd);
__asm__("l.nop 13");
/* Give a grace period for failure to restart of 1s */ mdelay(1000);
/* Whoops - the platform was unable to reboot. Tell the user! */ pr_emerg("Reboot failed -- System halted\n"); while (1);}
/* * This is used if a sys-off handler was not set by a power management * driver, in this case we can assume we are on a simulator. On * OpenRISC simulators l.nop 1 will trigger the simulator exit. */static void default_power_off(void){ __asm__("l.nop 1");}
/* * Similar to machine_power_off, but don't shut off power. Add code * here to freeze the system for e.g. post-mortem debug purpose when * possible. This halt has nothing to do with the idle halt. */void machine_halt(void){ printk(KERN_INFO "*** MACHINE HALT ***\n"); __asm__("l.nop 1");}
/* If or when software power-off is implemented, add code here. */void machine_power_off(void){ printk(KERN_INFO "*** MACHINE POWER OFF ***\n"); do_kernel_power_off(); default_power_off();}
/* * Send the doze signal to the cpu if available. * Make sure, that all interrupts are enabled */void arch_cpu_idle(void){ raw_local_irq_enable(); if (mfspr(SPR_UPR) & SPR_UPR_PMP) mtspr(SPR_PMR, mfspr(SPR_PMR) | SPR_PMR_DME); raw_local_irq_disable();}
void (*pm_power_off)(void) = NULL;EXPORT_SYMBOL(pm_power_off);
/* * When a process does an "exec", machine state like FPU and debug * registers need to be reset. This is a hook function for that. * Currently we don't have any such state to reset, so this is empty. */void flush_thread(void){}
void show_regs(struct pt_regs *regs){ show_regs_print_info(KERN_DEFAULT); /* __PHX__ cleanup this mess */ show_registers(regs);}
/* * Copy the thread-specific (arch specific) info from the current * process to the new one p */extern asmlinkage void ret_from_fork(void);
/* * copy_thread * @clone_flags: flags * @usp: user stack pointer or fn for kernel thread * @arg: arg to fn for kernel thread; always NULL for userspace thread * @p: the newly created task * @tls: the Thread Local Storage pointer for the new process * * At the top of a newly initialized kernel stack are two stacked pt_reg * structures. The first (topmost) is the userspace context of the thread. * The second is the kernelspace context of the thread. * * A kernel thread will not be returning to userspace, so the topmost pt_regs * struct can be uninitialized; it _does_ need to exist, though, because * a kernel thread can become a userspace thread by doing a kernel_execve, in * which case the topmost context will be initialized and used for 'returning' * to userspace. * * The second pt_reg struct needs to be initialized to 'return' to * ret_from_fork. A kernel thread will need to set r20 to the address of * a function to call into (with arg in r22); userspace threads need to set * r20 to NULL in which case ret_from_fork will just continue a return to * userspace. * * A kernel thread 'fn' may return; this is effectively what happens when * kernel_execve is called. In that case, the userspace pt_regs must have * been initialized (which kernel_execve takes care of, see start_thread * below); ret_from_fork will then continue its execution causing the * 'kernel thread' to return to userspace as a userspace thread. */
intcopy_thread(struct task_struct *p, const struct kernel_clone_args *args){ u64 clone_flags = args->flags; unsigned long usp = args->stack; unsigned long tls = args->tls; struct pt_regs *userregs; struct pt_regs *kregs; unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; unsigned long top_of_kernel_stack;
top_of_kernel_stack = sp;
/* Locate userspace context on stack... */ sp -= STACK_FRAME_OVERHEAD; /* redzone */ sp -= sizeof(struct pt_regs); userregs = (struct pt_regs *) sp;
/* ...and kernel context */ sp -= STACK_FRAME_OVERHEAD; /* redzone */ sp -= sizeof(struct pt_regs); kregs = (struct pt_regs *)sp;
if (unlikely(args->fn)) { memset(kregs, 0, sizeof(struct pt_regs)); kregs->gpr[20] = (unsigned long)args->fn; kregs->gpr[22] = (unsigned long)args->fn_arg; } else { *userregs = *current_pt_regs();
if (usp) userregs->sp = usp;
/* * For CLONE_SETTLS set "tp" (r10) to the TLS pointer. */ if (clone_flags & CLONE_SETTLS) userregs->gpr[10] = tls;
userregs->gpr[11] = 0; /* Result from fork() */
kregs->gpr[20] = 0; /* Userspace thread */ }
/* * _switch wants the kernel stack page in pt_regs->sp so that it * can restore it to thread_info->ksp... see _switch for details. */ kregs->sp = top_of_kernel_stack; kregs->gpr[9] = (unsigned long)ret_from_fork;
task_thread_info(p)->ksp = (unsigned long)kregs;
return 0;}
/* * Set up a thread for executing a new program */void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp){ unsigned long sr = mfspr(SPR_SR) & ~SPR_SR_SM;
memset(regs, 0, sizeof(struct pt_regs));
regs->pc = pc; regs->sr = sr; regs->sp = sp;}
extern struct thread_info *_switch(struct thread_info *old_ti, struct thread_info *new_ti);extern int lwa_flag;
struct task_struct *__switch_to(struct task_struct *old, struct task_struct *new){ struct task_struct *last; struct thread_info *new_ti, *old_ti; unsigned long flags;
local_irq_save(flags);
save_fpu(current);
/* current_set is an array of saved current pointers * (one for each cpu). we need them at user->kernel transition, * while we save them at kernel->user transition */ new_ti = new->stack; old_ti = old->stack;
lwa_flag = 0;
current_thread_info_set[smp_processor_id()] = new_ti; last = (_switch(old_ti, new_ti))->task;
restore_fpu(current);
local_irq_restore(flags);
return last;}
/* * Write out registers in core dump format, as defined by the * struct user_regs_struct */void dump_elf_thread(elf_greg_t *dest, struct pt_regs* regs){ dest[0] = 0; /* r0 */ memcpy(dest+1, regs->gpr+1, 31*sizeof(unsigned long)); dest[32] = regs->pc; dest[33] = regs->sr; dest[34] = 0; dest[35] = 0;}
unsigned long __get_wchan(struct task_struct *p){ /* TODO */
return 0;}