diff options
Diffstat (limited to 'arch/riscv/kernel/process.c')
| -rw-r--r-- | arch/riscv/kernel/process.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c new file mode 100644 index 000000000000..0d90dcc1fbd3 --- /dev/null +++ b/arch/riscv/kernel/process.c @@ -0,0 +1,129 @@ +/* + * Copyright (C) 2009 Sunplus Core Technology Co., Ltd. + * Chen Liqin <liqin.chen@sunplusct.com> + * Lennox Wu <lennox.wu@sunplusct.com> + * Copyright (C) 2012 Regents of the University of California + * Copyright (C) 2017 SiFive + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see the file COPYING, or write + * to the Free Software Foundation, Inc., + */ + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/sched/task_stack.h> +#include <linux/tick.h> +#include <linux/ptrace.h> + +#include <asm/unistd.h> +#include <asm/uaccess.h> +#include <asm/processor.h> +#include <asm/csr.h> +#include <asm/string.h> +#include <asm/switch_to.h> + +extern asmlinkage void ret_from_fork(void); +extern asmlinkage void ret_from_kernel_thread(void); + +void arch_cpu_idle(void) +{ + wait_for_interrupt(); + local_irq_enable(); +} + +void show_regs(struct pt_regs *regs) +{ + show_regs_print_info(KERN_DEFAULT); + + pr_cont("sepc: " REG_FMT " ra : " REG_FMT " sp : " REG_FMT "\n", + regs->sepc, regs->ra, regs->sp); + pr_cont(" gp : " REG_FMT " tp : " REG_FMT " t0 : " REG_FMT "\n", + regs->gp, regs->tp, regs->t0); + pr_cont(" t1 : " REG_FMT " t2 : " REG_FMT " s0 : " REG_FMT "\n", + regs->t1, regs->t2, regs->s0); + pr_cont(" s1 : " REG_FMT " a0 : " REG_FMT " a1 : " REG_FMT "\n", + regs->s1, regs->a0, regs->a1); + pr_cont(" a2 : " REG_FMT " a3 : " REG_FMT " a4 : " REG_FMT "\n", + regs->a2, regs->a3, regs->a4); + pr_cont(" a5 : " REG_FMT " a6 : " REG_FMT " a7 : " REG_FMT "\n", + regs->a5, regs->a6, regs->a7); + pr_cont(" s2 : " REG_FMT " s3 : " REG_FMT " s4 : " REG_FMT "\n", + regs->s2, regs->s3, regs->s4); + pr_cont(" s5 : " REG_FMT " s6 : " REG_FMT " s7 : " REG_FMT "\n", + regs->s5, regs->s6, regs->s7); + pr_cont(" s8 : " REG_FMT " s9 : " REG_FMT " s10: " REG_FMT "\n", + regs->s8, regs->s9, regs->s10); + pr_cont(" s11: " REG_FMT " t3 : " REG_FMT " t4 : " REG_FMT "\n", + regs->s11, regs->t3, regs->t4); + pr_cont(" t5 : " REG_FMT " t6 : " REG_FMT "\n", + regs->t5, regs->t6); + + pr_cont("sstatus: " REG_FMT " sbadaddr: " REG_FMT " scause: " REG_FMT "\n", + regs->sstatus, regs->sbadaddr, regs->scause); +} + +void start_thread(struct pt_regs *regs, unsigned long pc, + unsigned long sp) +{ + regs->sstatus = SR_PIE /* User mode, irqs on */ | SR_FS_INITIAL; + regs->sepc = pc; + regs->sp = sp; + set_fs(USER_DS); +} + +void flush_thread(void) +{ + /* + * Reset FPU context + * frm: round to nearest, ties to even (IEEE default) + * fflags: accrued exceptions cleared + */ + memset(¤t->thread.fstate, 0, sizeof(current->thread.fstate)); +} + +int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) +{ + fstate_save(src, task_pt_regs(src)); + *dst = *src; + return 0; +} + +int copy_thread(unsigned long clone_flags, unsigned long usp, + unsigned long arg, struct task_struct *p) +{ + struct pt_regs *childregs = task_pt_regs(p); + + /* p->thread holds context to be restored by __switch_to() */ + if (unlikely(p->flags & PF_KTHREAD)) { + /* Kernel thread */ + const register unsigned long gp __asm__ ("gp"); + memset(childregs, 0, sizeof(struct pt_regs)); + childregs->gp = gp; + childregs->sstatus = SR_PS | SR_PIE; /* Supervisor, irqs on */ + + p->thread.ra = (unsigned long)ret_from_kernel_thread; + p->thread.s[0] = usp; /* fn */ + p->thread.s[1] = arg; + } else { + *childregs = *(current_pt_regs()); + if (usp) /* User fork */ + childregs->sp = usp; + if (clone_flags & CLONE_SETTLS) + childregs->tp = childregs->a5; + childregs->a0 = 0; /* Return value of fork() */ + p->thread.ra = (unsigned long)ret_from_fork; + } + p->thread.sp = (unsigned long)childregs; /* kernel sp */ + return 0; +} |