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 #include <asm/cpuidle.h> 27 28 register unsigned long gp_in_global __asm__("gp"); 29 30 #if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK) 31 #include <linux/stackprotector.h> 32 unsigned long __stack_chk_guard __read_mostly; 33 EXPORT_SYMBOL(__stack_chk_guard); 34 #endif 35 36 extern asmlinkage void ret_from_fork(void); 37 extern asmlinkage void ret_from_kernel_thread(void); 38 39 void arch_cpu_idle(void) 40 { 41 cpu_do_idle(); 42 raw_local_irq_enable(); 43 } 44 45 void __show_regs(struct pt_regs *regs) 46 { 47 show_regs_print_info(KERN_DEFAULT); 48 49 if (!user_mode(regs)) { 50 pr_cont("epc : %pS\n", (void *)regs->epc); 51 pr_cont(" ra : %pS\n", (void *)regs->ra); 52 } 53 54 pr_cont("epc : " REG_FMT " ra : " REG_FMT " sp : " REG_FMT "\n", 55 regs->epc, regs->ra, regs->sp); 56 pr_cont(" gp : " REG_FMT " tp : " REG_FMT " t0 : " REG_FMT "\n", 57 regs->gp, regs->tp, regs->t0); 58 pr_cont(" t1 : " REG_FMT " t2 : " REG_FMT " s0 : " REG_FMT "\n", 59 regs->t1, regs->t2, regs->s0); 60 pr_cont(" s1 : " REG_FMT " a0 : " REG_FMT " a1 : " REG_FMT "\n", 61 regs->s1, regs->a0, regs->a1); 62 pr_cont(" a2 : " REG_FMT " a3 : " REG_FMT " a4 : " REG_FMT "\n", 63 regs->a2, regs->a3, regs->a4); 64 pr_cont(" a5 : " REG_FMT " a6 : " REG_FMT " a7 : " REG_FMT "\n", 65 regs->a5, regs->a6, regs->a7); 66 pr_cont(" s2 : " REG_FMT " s3 : " REG_FMT " s4 : " REG_FMT "\n", 67 regs->s2, regs->s3, regs->s4); 68 pr_cont(" s5 : " REG_FMT " s6 : " REG_FMT " s7 : " REG_FMT "\n", 69 regs->s5, regs->s6, regs->s7); 70 pr_cont(" s8 : " REG_FMT " s9 : " REG_FMT " s10: " REG_FMT "\n", 71 regs->s8, regs->s9, regs->s10); 72 pr_cont(" s11: " REG_FMT " t3 : " REG_FMT " t4 : " REG_FMT "\n", 73 regs->s11, regs->t3, regs->t4); 74 pr_cont(" t5 : " REG_FMT " t6 : " REG_FMT "\n", 75 regs->t5, regs->t6); 76 77 pr_cont("status: " REG_FMT " badaddr: " REG_FMT " cause: " REG_FMT "\n", 78 regs->status, regs->badaddr, regs->cause); 79 } 80 void show_regs(struct pt_regs *regs) 81 { 82 __show_regs(regs); 83 if (!user_mode(regs)) 84 dump_backtrace(regs, NULL, KERN_DEFAULT); 85 } 86 87 void start_thread(struct pt_regs *regs, unsigned long pc, 88 unsigned long sp) 89 { 90 regs->status = SR_PIE; 91 if (has_fpu()) { 92 regs->status |= SR_FS_INITIAL; 93 /* 94 * Restore the initial value to the FP register 95 * before starting the user program. 96 */ 97 fstate_restore(current, regs); 98 } 99 regs->epc = pc; 100 regs->sp = sp; 101 } 102 103 void flush_thread(void) 104 { 105 #ifdef CONFIG_FPU 106 /* 107 * Reset FPU state and context 108 * frm: round to nearest, ties to even (IEEE default) 109 * fflags: accrued exceptions cleared 110 */ 111 fstate_off(current, task_pt_regs(current)); 112 memset(¤t->thread.fstate, 0, sizeof(current->thread.fstate)); 113 #endif 114 } 115 116 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) 117 { 118 fstate_save(src, task_pt_regs(src)); 119 *dst = *src; 120 return 0; 121 } 122 123 int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg, 124 struct task_struct *p, unsigned long tls) 125 { 126 struct pt_regs *childregs = task_pt_regs(p); 127 128 /* p->thread holds context to be restored by __switch_to() */ 129 if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { 130 /* Kernel thread */ 131 memset(childregs, 0, sizeof(struct pt_regs)); 132 childregs->gp = gp_in_global; 133 /* Supervisor/Machine, irqs on: */ 134 childregs->status = SR_PP | SR_PIE; 135 136 p->thread.ra = (unsigned long)ret_from_kernel_thread; 137 p->thread.s[0] = usp; /* fn */ 138 p->thread.s[1] = arg; 139 } else { 140 *childregs = *(current_pt_regs()); 141 if (usp) /* User fork */ 142 childregs->sp = usp; 143 if (clone_flags & CLONE_SETTLS) 144 childregs->tp = tls; 145 childregs->a0 = 0; /* Return value of fork() */ 146 p->thread.ra = (unsigned long)ret_from_fork; 147 } 148 p->thread.sp = (unsigned long)childregs; /* kernel sp */ 149 return 0; 150 } 151