1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2009 Sunplus Core Technology Co., Ltd. 4 * Chen Liqin <liqin.chen@sunplusct.com> 5 * Lennox Wu <lennox.wu@sunplusct.com> 6 * Copyright (C) 2012 Regents of the University of California 7 * Copyright (C) 2017 SiFive 8 */ 9 10 #include <linux/cpu.h> 11 #include <linux/kernel.h> 12 #include <linux/sched.h> 13 #include <linux/sched/task_stack.h> 14 #include <linux/tick.h> 15 #include <linux/ptrace.h> 16 #include <linux/uaccess.h> 17 18 #include <asm/unistd.h> 19 #include <asm/processor.h> 20 #include <asm/csr.h> 21 #include <asm/stacktrace.h> 22 #include <asm/string.h> 23 #include <asm/switch_to.h> 24 #include <asm/thread_info.h> 25 26 register unsigned long gp_in_global __asm__("gp"); 27 28 #if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK) 29 #include <linux/stackprotector.h> 30 unsigned long __stack_chk_guard __read_mostly; 31 EXPORT_SYMBOL(__stack_chk_guard); 32 #endif 33 34 extern asmlinkage void ret_from_fork(void); 35 extern asmlinkage void ret_from_kernel_thread(void); 36 37 void arch_cpu_idle(void) 38 { 39 wait_for_interrupt(); 40 raw_local_irq_enable(); 41 } 42 43 void __show_regs(struct pt_regs *regs) 44 { 45 show_regs_print_info(KERN_DEFAULT); 46 47 if (!user_mode(regs)) { 48 pr_cont("epc : %pS\n", (void *)regs->epc); 49 pr_cont(" ra : %pS\n", (void *)regs->ra); 50 } 51 52 pr_cont("epc : " REG_FMT " ra : " REG_FMT " sp : " REG_FMT "\n", 53 regs->epc, regs->ra, regs->sp); 54 pr_cont(" gp : " REG_FMT " tp : " REG_FMT " t0 : " REG_FMT "\n", 55 regs->gp, regs->tp, regs->t0); 56 pr_cont(" t1 : " REG_FMT " t2 : " REG_FMT " s0 : " REG_FMT "\n", 57 regs->t1, regs->t2, regs->s0); 58 pr_cont(" s1 : " REG_FMT " a0 : " REG_FMT " a1 : " REG_FMT "\n", 59 regs->s1, regs->a0, regs->a1); 60 pr_cont(" a2 : " REG_FMT " a3 : " REG_FMT " a4 : " REG_FMT "\n", 61 regs->a2, regs->a3, regs->a4); 62 pr_cont(" a5 : " REG_FMT " a6 : " REG_FMT " a7 : " REG_FMT "\n", 63 regs->a5, regs->a6, regs->a7); 64 pr_cont(" s2 : " REG_FMT " s3 : " REG_FMT " s4 : " REG_FMT "\n", 65 regs->s2, regs->s3, regs->s4); 66 pr_cont(" s5 : " REG_FMT " s6 : " REG_FMT " s7 : " REG_FMT "\n", 67 regs->s5, regs->s6, regs->s7); 68 pr_cont(" s8 : " REG_FMT " s9 : " REG_FMT " s10: " REG_FMT "\n", 69 regs->s8, regs->s9, regs->s10); 70 pr_cont(" s11: " REG_FMT " t3 : " REG_FMT " t4 : " REG_FMT "\n", 71 regs->s11, regs->t3, regs->t4); 72 pr_cont(" t5 : " REG_FMT " t6 : " REG_FMT "\n", 73 regs->t5, regs->t6); 74 75 pr_cont("status: " REG_FMT " badaddr: " REG_FMT " cause: " REG_FMT "\n", 76 regs->status, regs->badaddr, regs->cause); 77 } 78 void show_regs(struct pt_regs *regs) 79 { 80 __show_regs(regs); 81 if (!user_mode(regs)) 82 dump_backtrace(regs, NULL, KERN_DEFAULT); 83 } 84 85 void start_thread(struct pt_regs *regs, unsigned long pc, 86 unsigned long sp) 87 { 88 regs->status = SR_PIE; 89 if (has_fpu) { 90 regs->status |= SR_FS_INITIAL; 91 /* 92 * Restore the initial value to the FP register 93 * before starting the user program. 94 */ 95 fstate_restore(current, regs); 96 } 97 regs->epc = pc; 98 regs->sp = sp; 99 } 100 101 void flush_thread(void) 102 { 103 #ifdef CONFIG_FPU 104 /* 105 * Reset FPU state and context 106 * frm: round to nearest, ties to even (IEEE default) 107 * fflags: accrued exceptions cleared 108 */ 109 fstate_off(current, task_pt_regs(current)); 110 memset(¤t->thread.fstate, 0, sizeof(current->thread.fstate)); 111 #endif 112 } 113 114 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) 115 { 116 fstate_save(src, task_pt_regs(src)); 117 *dst = *src; 118 return 0; 119 } 120 121 int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg, 122 struct task_struct *p, unsigned long tls) 123 { 124 struct pt_regs *childregs = task_pt_regs(p); 125 126 /* p->thread holds context to be restored by __switch_to() */ 127 if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { 128 /* Kernel thread */ 129 memset(childregs, 0, sizeof(struct pt_regs)); 130 childregs->gp = gp_in_global; 131 /* Supervisor/Machine, irqs on: */ 132 childregs->status = SR_PP | SR_PIE; 133 134 p->thread.ra = (unsigned long)ret_from_kernel_thread; 135 p->thread.s[0] = usp; /* fn */ 136 p->thread.s[1] = arg; 137 } else { 138 *childregs = *(current_pt_regs()); 139 if (usp) /* User fork */ 140 childregs->sp = usp; 141 if (clone_flags & CLONE_SETTLS) 142 childregs->tp = tls; 143 childregs->a0 = 0; /* Return value of fork() */ 144 p->thread.ra = (unsigned long)ret_from_fork; 145 } 146 p->thread.sp = (unsigned long)childregs; /* kernel sp */ 147 return 0; 148 } 149