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/debug.h> 14 #include <linux/sched/task_stack.h> 15 #include <linux/tick.h> 16 #include <linux/ptrace.h> 17 #include <linux/uaccess.h> 18 19 #include <asm/unistd.h> 20 #include <asm/processor.h> 21 #include <asm/csr.h> 22 #include <asm/stacktrace.h> 23 #include <asm/string.h> 24 #include <asm/switch_to.h> 25 #include <asm/thread_info.h> 26 27 register unsigned long gp_in_global __asm__("gp"); 28 29 #if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK) 30 #include <linux/stackprotector.h> 31 unsigned long __stack_chk_guard __read_mostly; 32 EXPORT_SYMBOL(__stack_chk_guard); 33 #endif 34 35 extern asmlinkage void ret_from_fork(void); 36 extern asmlinkage void ret_from_kernel_thread(void); 37 38 void arch_cpu_idle(void) 39 { 40 wait_for_interrupt(); 41 raw_local_irq_enable(); 42 } 43 44 void __show_regs(struct pt_regs *regs) 45 { 46 show_regs_print_info(KERN_DEFAULT); 47 48 if (!user_mode(regs)) { 49 pr_cont("epc : %pS\n", (void *)regs->epc); 50 pr_cont(" ra : %pS\n", (void *)regs->ra); 51 } 52 53 pr_cont("epc : " REG_FMT " ra : " REG_FMT " sp : " REG_FMT "\n", 54 regs->epc, regs->ra, regs->sp); 55 pr_cont(" gp : " REG_FMT " tp : " REG_FMT " t0 : " REG_FMT "\n", 56 regs->gp, regs->tp, regs->t0); 57 pr_cont(" t1 : " REG_FMT " t2 : " REG_FMT " s0 : " REG_FMT "\n", 58 regs->t1, regs->t2, regs->s0); 59 pr_cont(" s1 : " REG_FMT " a0 : " REG_FMT " a1 : " REG_FMT "\n", 60 regs->s1, regs->a0, regs->a1); 61 pr_cont(" a2 : " REG_FMT " a3 : " REG_FMT " a4 : " REG_FMT "\n", 62 regs->a2, regs->a3, regs->a4); 63 pr_cont(" a5 : " REG_FMT " a6 : " REG_FMT " a7 : " REG_FMT "\n", 64 regs->a5, regs->a6, regs->a7); 65 pr_cont(" s2 : " REG_FMT " s3 : " REG_FMT " s4 : " REG_FMT "\n", 66 regs->s2, regs->s3, regs->s4); 67 pr_cont(" s5 : " REG_FMT " s6 : " REG_FMT " s7 : " REG_FMT "\n", 68 regs->s5, regs->s6, regs->s7); 69 pr_cont(" s8 : " REG_FMT " s9 : " REG_FMT " s10: " REG_FMT "\n", 70 regs->s8, regs->s9, regs->s10); 71 pr_cont(" s11: " REG_FMT " t3 : " REG_FMT " t4 : " REG_FMT "\n", 72 regs->s11, regs->t3, regs->t4); 73 pr_cont(" t5 : " REG_FMT " t6 : " REG_FMT "\n", 74 regs->t5, regs->t6); 75 76 pr_cont("status: " REG_FMT " badaddr: " REG_FMT " cause: " REG_FMT "\n", 77 regs->status, regs->badaddr, regs->cause); 78 } 79 void show_regs(struct pt_regs *regs) 80 { 81 __show_regs(regs); 82 if (!user_mode(regs)) 83 dump_backtrace(regs, NULL, KERN_DEFAULT); 84 } 85 86 void start_thread(struct pt_regs *regs, unsigned long pc, 87 unsigned long sp) 88 { 89 regs->status = SR_PIE; 90 if (has_fpu()) { 91 regs->status |= SR_FS_INITIAL; 92 /* 93 * Restore the initial value to the FP register 94 * before starting the user program. 95 */ 96 fstate_restore(current, regs); 97 } 98 regs->epc = pc; 99 regs->sp = sp; 100 } 101 102 void flush_thread(void) 103 { 104 #ifdef CONFIG_FPU 105 /* 106 * Reset FPU state and context 107 * frm: round to nearest, ties to even (IEEE default) 108 * fflags: accrued exceptions cleared 109 */ 110 fstate_off(current, task_pt_regs(current)); 111 memset(¤t->thread.fstate, 0, sizeof(current->thread.fstate)); 112 #endif 113 } 114 115 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) 116 { 117 fstate_save(src, task_pt_regs(src)); 118 *dst = *src; 119 return 0; 120 } 121 122 int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg, 123 struct task_struct *p, unsigned long tls) 124 { 125 struct pt_regs *childregs = task_pt_regs(p); 126 127 /* p->thread holds context to be restored by __switch_to() */ 128 if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { 129 /* Kernel thread */ 130 memset(childregs, 0, sizeof(struct pt_regs)); 131 childregs->gp = gp_in_global; 132 /* Supervisor/Machine, irqs on: */ 133 childregs->status = SR_PP | SR_PIE; 134 135 p->thread.ra = (unsigned long)ret_from_kernel_thread; 136 p->thread.s[0] = usp; /* fn */ 137 p->thread.s[1] = arg; 138 } else { 139 *childregs = *(current_pt_regs()); 140 if (usp) /* User fork */ 141 childregs->sp = usp; 142 if (clone_flags & CLONE_SETTLS) 143 childregs->tp = tls; 144 childregs->a0 = 0; /* Return value of fork() */ 145 p->thread.ra = (unsigned long)ret_from_fork; 146 } 147 p->thread.sp = (unsigned long)childregs; /* kernel sp */ 148 return 0; 149 } 150