1 // SPDX-License-Identifier: GPL-2.0 2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. 3 4 #include <linux/module.h> 5 #include <linux/version.h> 6 #include <linux/sched.h> 7 #include <linux/sched/task_stack.h> 8 #include <linux/sched/debug.h> 9 #include <linux/delay.h> 10 #include <linux/kallsyms.h> 11 #include <linux/uaccess.h> 12 #include <linux/ptrace.h> 13 14 #include <asm/elf.h> 15 #include <abi/reg_ops.h> 16 17 struct cpuinfo_csky cpu_data[NR_CPUS]; 18 19 #ifdef CONFIG_STACKPROTECTOR 20 #include <linux/stackprotector.h> 21 unsigned long __stack_chk_guard __read_mostly; 22 EXPORT_SYMBOL(__stack_chk_guard); 23 #endif 24 25 asmlinkage void ret_from_fork(void); 26 asmlinkage void ret_from_kernel_thread(void); 27 28 /* 29 * Some archs flush debug and FPU info here 30 */ 31 void flush_thread(void){} 32 33 /* 34 * Return saved PC from a blocked thread 35 */ 36 unsigned long thread_saved_pc(struct task_struct *tsk) 37 { 38 struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp; 39 40 return sw->r15; 41 } 42 43 int copy_thread(unsigned long clone_flags, 44 unsigned long usp, 45 unsigned long kthread_arg, 46 struct task_struct *p) 47 { 48 struct switch_stack *childstack; 49 struct pt_regs *childregs = task_pt_regs(p); 50 51 #ifdef CONFIG_CPU_HAS_FPU 52 save_to_user_fp(&p->thread.user_fp); 53 #endif 54 55 childstack = ((struct switch_stack *) childregs) - 1; 56 memset(childstack, 0, sizeof(struct switch_stack)); 57 58 /* setup ksp for switch_to !!! */ 59 p->thread.ksp = (unsigned long)childstack; 60 61 if (unlikely(p->flags & PF_KTHREAD)) { 62 memset(childregs, 0, sizeof(struct pt_regs)); 63 childstack->r15 = (unsigned long) ret_from_kernel_thread; 64 childstack->r10 = kthread_arg; 65 childstack->r9 = usp; 66 childregs->sr = mfcr("psr"); 67 } else { 68 *childregs = *(current_pt_regs()); 69 if (usp) 70 childregs->usp = usp; 71 if (clone_flags & CLONE_SETTLS) 72 task_thread_info(p)->tp_value = childregs->tls 73 = childregs->regs[0]; 74 75 childregs->a0 = 0; 76 childstack->r15 = (unsigned long) ret_from_fork; 77 } 78 79 return 0; 80 } 81 82 /* Fill in the fpu structure for a core dump. */ 83 int dump_fpu(struct pt_regs *regs, struct user_fp *fpu) 84 { 85 memcpy(fpu, ¤t->thread.user_fp, sizeof(*fpu)); 86 return 1; 87 } 88 EXPORT_SYMBOL(dump_fpu); 89 90 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *pr_regs) 91 { 92 struct pt_regs *regs = task_pt_regs(tsk); 93 94 /* NOTE: usp is error value. */ 95 ELF_CORE_COPY_REGS((*pr_regs), regs) 96 97 return 1; 98 } 99 100 unsigned long get_wchan(struct task_struct *p) 101 { 102 unsigned long lr; 103 unsigned long *fp, *stack_start, *stack_end; 104 int count = 0; 105 106 if (!p || p == current || p->state == TASK_RUNNING) 107 return 0; 108 109 stack_start = (unsigned long *)end_of_stack(p); 110 stack_end = (unsigned long *)(task_stack_page(p) + THREAD_SIZE); 111 112 fp = (unsigned long *) thread_saved_fp(p); 113 do { 114 if (fp < stack_start || fp > stack_end) 115 return 0; 116 #ifdef CONFIG_STACKTRACE 117 lr = fp[1]; 118 fp = (unsigned long *)fp[0]; 119 #else 120 lr = *fp++; 121 #endif 122 if (!in_sched_functions(lr) && 123 __kernel_text_address(lr)) 124 return lr; 125 } while (count++ < 16); 126 127 return 0; 128 } 129 EXPORT_SYMBOL(get_wchan); 130 131 #ifndef CONFIG_CPU_PM_NONE 132 void arch_cpu_idle(void) 133 { 134 #ifdef CONFIG_CPU_PM_WAIT 135 asm volatile("wait\n"); 136 #endif 137 138 #ifdef CONFIG_CPU_PM_DOZE 139 asm volatile("doze\n"); 140 #endif 141 142 #ifdef CONFIG_CPU_PM_STOP 143 asm volatile("stop\n"); 144 #endif 145 local_irq_enable(); 146 } 147 #endif 148