| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * 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 |
| */ |
| |
| #include <linux/cpu.h> |
| #include <linux/kernel.h> |
| #include <linux/sched.h> |
| #include <linux/sched/debug.h> |
| #include <linux/sched/task_stack.h> |
| #include <linux/tick.h> |
| #include <linux/ptrace.h> |
| #include <linux/uaccess.h> |
| |
| #include <asm/unistd.h> |
| #include <asm/processor.h> |
| #include <asm/csr.h> |
| #include <asm/stacktrace.h> |
| #include <asm/string.h> |
| #include <asm/switch_to.h> |
| #include <asm/thread_info.h> |
| #include <asm/cpuidle.h> |
| #include <asm/vector.h> |
| #include <asm/cpufeature.h> |
| |
| register unsigned long gp_in_global __asm__("gp"); |
| |
| #if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK) |
| #include <linux/stackprotector.h> |
| unsigned long __stack_chk_guard __read_mostly; |
| EXPORT_SYMBOL(__stack_chk_guard); |
| #endif |
| |
| extern asmlinkage void ret_from_fork(void); |
| |
| void noinstr arch_cpu_idle(void) |
| { |
| cpu_do_idle(); |
| } |
| |
| int set_unalign_ctl(struct task_struct *tsk, unsigned int val) |
| { |
| if (!unaligned_ctl_available()) |
| return -EINVAL; |
| |
| tsk->thread.align_ctl = val; |
| return 0; |
| } |
| |
| int get_unalign_ctl(struct task_struct *tsk, unsigned long adr) |
| { |
| if (!unaligned_ctl_available()) |
| return -EINVAL; |
| |
| return put_user(tsk->thread.align_ctl, (unsigned long __user *)adr); |
| } |
| |
| void __show_regs(struct pt_regs *regs) |
| { |
| show_regs_print_info(KERN_DEFAULT); |
| |
| if (!user_mode(regs)) { |
| pr_cont("epc : %pS\n", (void *)regs->epc); |
| pr_cont(" ra : %pS\n", (void *)regs->ra); |
| } |
| |
| pr_cont("epc : " REG_FMT " ra : " REG_FMT " sp : " REG_FMT "\n", |
| regs->epc, 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("status: " REG_FMT " badaddr: " REG_FMT " cause: " REG_FMT "\n", |
| regs->status, regs->badaddr, regs->cause); |
| } |
| void show_regs(struct pt_regs *regs) |
| { |
| __show_regs(regs); |
| if (!user_mode(regs)) |
| dump_backtrace(regs, NULL, KERN_DEFAULT); |
| } |
| |
| #ifdef CONFIG_COMPAT |
| static bool compat_mode_supported __read_mostly; |
| |
| bool compat_elf_check_arch(Elf32_Ehdr *hdr) |
| { |
| return compat_mode_supported && |
| hdr->e_machine == EM_RISCV && |
| hdr->e_ident[EI_CLASS] == ELFCLASS32; |
| } |
| |
| static int __init compat_mode_detect(void) |
| { |
| unsigned long tmp = csr_read(CSR_STATUS); |
| |
| csr_write(CSR_STATUS, (tmp & ~SR_UXL) | SR_UXL_32); |
| compat_mode_supported = |
| (csr_read(CSR_STATUS) & SR_UXL) == SR_UXL_32; |
| |
| csr_write(CSR_STATUS, tmp); |
| |
| pr_info("riscv: ELF compat mode %s", |
| compat_mode_supported ? "supported" : "unsupported"); |
| |
| return 0; |
| } |
| early_initcall(compat_mode_detect); |
| #endif |
| |
| void start_thread(struct pt_regs *regs, unsigned long pc, |
| unsigned long sp) |
| { |
| regs->status = SR_PIE; |
| if (has_fpu()) { |
| regs->status |= SR_FS_INITIAL; |
| /* |
| * Restore the initial value to the FP register |
| * before starting the user program. |
| */ |
| fstate_restore(current, regs); |
| } |
| regs->epc = pc; |
| regs->sp = sp; |
| |
| #ifdef CONFIG_64BIT |
| regs->status &= ~SR_UXL; |
| |
| if (is_compat_task()) |
| regs->status |= SR_UXL_32; |
| else |
| regs->status |= SR_UXL_64; |
| #endif |
| } |
| |
| void flush_thread(void) |
| { |
| #ifdef CONFIG_FPU |
| /* |
| * Reset FPU state and context |
| * frm: round to nearest, ties to even (IEEE default) |
| * fflags: accrued exceptions cleared |
| */ |
| fstate_off(current, task_pt_regs(current)); |
| memset(¤t->thread.fstate, 0, sizeof(current->thread.fstate)); |
| #endif |
| #ifdef CONFIG_RISCV_ISA_V |
| /* Reset vector state */ |
| riscv_v_vstate_ctrl_init(current); |
| riscv_v_vstate_off(task_pt_regs(current)); |
| kfree(current->thread.vstate.datap); |
| memset(¤t->thread.vstate, 0, sizeof(struct __riscv_v_ext_state)); |
| clear_tsk_thread_flag(current, TIF_RISCV_V_DEFER_RESTORE); |
| #endif |
| } |
| |
| void arch_release_task_struct(struct task_struct *tsk) |
| { |
| /* Free the vector context of datap. */ |
| if (has_vector()) |
| riscv_v_thread_free(tsk); |
| } |
| |
| int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) |
| { |
| fstate_save(src, task_pt_regs(src)); |
| *dst = *src; |
| /* clear entire V context, including datap for a new task */ |
| memset(&dst->thread.vstate, 0, sizeof(struct __riscv_v_ext_state)); |
| memset(&dst->thread.kernel_vstate, 0, sizeof(struct __riscv_v_ext_state)); |
| clear_tsk_thread_flag(dst, TIF_RISCV_V_DEFER_RESTORE); |
| |
| return 0; |
| } |
| |
| int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) |
| { |
| unsigned long clone_flags = args->flags; |
| unsigned long usp = args->stack; |
| unsigned long tls = args->tls; |
| struct pt_regs *childregs = task_pt_regs(p); |
| |
| memset(&p->thread.s, 0, sizeof(p->thread.s)); |
| |
| /* p->thread holds context to be restored by __switch_to() */ |
| if (unlikely(args->fn)) { |
| /* Kernel thread */ |
| memset(childregs, 0, sizeof(struct pt_regs)); |
| childregs->gp = gp_in_global; |
| /* Supervisor/Machine, irqs on: */ |
| childregs->status = SR_PP | SR_PIE; |
| |
| p->thread.s[0] = (unsigned long)args->fn; |
| p->thread.s[1] = (unsigned long)args->fn_arg; |
| } else { |
| *childregs = *(current_pt_regs()); |
| /* Turn off status.VS */ |
| riscv_v_vstate_off(childregs); |
| if (usp) /* User fork */ |
| childregs->sp = usp; |
| if (clone_flags & CLONE_SETTLS) |
| childregs->tp = tls; |
| childregs->a0 = 0; /* Return value of fork() */ |
| p->thread.s[0] = 0; |
| } |
| p->thread.riscv_v_flags = 0; |
| if (has_vector()) |
| riscv_v_thread_alloc(p); |
| p->thread.ra = (unsigned long)ret_from_fork; |
| p->thread.sp = (unsigned long)childregs; /* kernel sp */ |
| return 0; |
| } |
| |
| void __init arch_task_cache_init(void) |
| { |
| riscv_v_setup_ctx_cache(); |
| } |