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#include <asm/vector.h>
 28#include <asm/cpufeature.h>
 29
 
 
 30#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK)
 31#include <linux/stackprotector.h>
 32unsigned long __stack_chk_guard __read_mostly;
 33EXPORT_SYMBOL(__stack_chk_guard);
 34#endif
 35
 36extern asmlinkage void ret_from_fork(void);
 37
 38void noinstr arch_cpu_idle(void)
 39{
 40	cpu_do_idle();
 41}
 42
 43int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
 44{
 45	if (!unaligned_ctl_available())
 46		return -EINVAL;
 47
 48	tsk->thread.align_ctl = val;
 49	return 0;
 50}
 51
 52int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
 53{
 54	if (!unaligned_ctl_available())
 55		return -EINVAL;
 56
 57	return put_user(tsk->thread.align_ctl, (unsigned long __user *)adr);
 58}
 59
 60void __show_regs(struct pt_regs *regs)
 61{
 62	show_regs_print_info(KERN_DEFAULT);
 63
 64	if (!user_mode(regs)) {
 65		pr_cont("epc : %pS\n", (void *)regs->epc);
 66		pr_cont(" ra : %pS\n", (void *)regs->ra);
 67	}
 68
 69	pr_cont("epc : " REG_FMT " ra : " REG_FMT " sp : " REG_FMT "\n",
 70		regs->epc, regs->ra, regs->sp);
 71	pr_cont(" gp : " REG_FMT " tp : " REG_FMT " t0 : " REG_FMT "\n",
 72		regs->gp, regs->tp, regs->t0);
 73	pr_cont(" t1 : " REG_FMT " t2 : " REG_FMT " s0 : " REG_FMT "\n",
 74		regs->t1, regs->t2, regs->s0);
 75	pr_cont(" s1 : " REG_FMT " a0 : " REG_FMT " a1 : " REG_FMT "\n",
 76		regs->s1, regs->a0, regs->a1);
 77	pr_cont(" a2 : " REG_FMT " a3 : " REG_FMT " a4 : " REG_FMT "\n",
 78		regs->a2, regs->a3, regs->a4);
 79	pr_cont(" a5 : " REG_FMT " a6 : " REG_FMT " a7 : " REG_FMT "\n",
 80		regs->a5, regs->a6, regs->a7);
 81	pr_cont(" s2 : " REG_FMT " s3 : " REG_FMT " s4 : " REG_FMT "\n",
 82		regs->s2, regs->s3, regs->s4);
 83	pr_cont(" s5 : " REG_FMT " s6 : " REG_FMT " s7 : " REG_FMT "\n",
 84		regs->s5, regs->s6, regs->s7);
 85	pr_cont(" s8 : " REG_FMT " s9 : " REG_FMT " s10: " REG_FMT "\n",
 86		regs->s8, regs->s9, regs->s10);
 87	pr_cont(" s11: " REG_FMT " t3 : " REG_FMT " t4 : " REG_FMT "\n",
 88		regs->s11, regs->t3, regs->t4);
 89	pr_cont(" t5 : " REG_FMT " t6 : " REG_FMT "\n",
 90		regs->t5, regs->t6);
 91
 92	pr_cont("status: " REG_FMT " badaddr: " REG_FMT " cause: " REG_FMT "\n",
 93		regs->status, regs->badaddr, regs->cause);
 94}
 95void show_regs(struct pt_regs *regs)
 96{
 97	__show_regs(regs);
 98	if (!user_mode(regs))
 99		dump_backtrace(regs, NULL, KERN_DEFAULT);
100}
101
102#ifdef CONFIG_COMPAT
103static bool compat_mode_supported __read_mostly;
104
105bool compat_elf_check_arch(Elf32_Ehdr *hdr)
106{
107	return compat_mode_supported &&
108	       hdr->e_machine == EM_RISCV &&
109	       hdr->e_ident[EI_CLASS] == ELFCLASS32;
110}
111
112static int __init compat_mode_detect(void)
113{
114	unsigned long tmp = csr_read(CSR_STATUS);
115
116	csr_write(CSR_STATUS, (tmp & ~SR_UXL) | SR_UXL_32);
117	compat_mode_supported =
118			(csr_read(CSR_STATUS) & SR_UXL) == SR_UXL_32;
119
120	csr_write(CSR_STATUS, tmp);
121
122	pr_info("riscv: ELF compat mode %s",
123			compat_mode_supported ? "supported" : "unsupported");
124
125	return 0;
126}
127early_initcall(compat_mode_detect);
128#endif
129
130void start_thread(struct pt_regs *regs, unsigned long pc,
131	unsigned long sp)
132{
133	regs->status = SR_PIE;
134	if (has_fpu()) {
135		regs->status |= SR_FS_INITIAL;
136		/*
137		 * Restore the initial value to the FP register
138		 * before starting the user program.
139		 */
140		fstate_restore(current, regs);
141	}
142	regs->epc = pc;
143	regs->sp = sp;
144
145#ifdef CONFIG_64BIT
146	regs->status &= ~SR_UXL;
147
148	if (is_compat_task())
149		regs->status |= SR_UXL_32;
150	else
151		regs->status |= SR_UXL_64;
152#endif
153}
154
155void flush_thread(void)
156{
157#ifdef CONFIG_FPU
158	/*
159	 * Reset FPU state and context
160	 *	frm: round to nearest, ties to even (IEEE default)
161	 *	fflags: accrued exceptions cleared
162	 */
163	fstate_off(current, task_pt_regs(current));
164	memset(&current->thread.fstate, 0, sizeof(current->thread.fstate));
165#endif
166#ifdef CONFIG_RISCV_ISA_V
167	/* Reset vector state */
168	riscv_v_vstate_ctrl_init(current);
169	riscv_v_vstate_off(task_pt_regs(current));
170	kfree(current->thread.vstate.datap);
171	memset(&current->thread.vstate, 0, sizeof(struct __riscv_v_ext_state));
172	clear_tsk_thread_flag(current, TIF_RISCV_V_DEFER_RESTORE);
173#endif
174}
175
176void arch_release_task_struct(struct task_struct *tsk)
177{
178	/* Free the vector context of datap. */
179	if (has_vector())
180		riscv_v_thread_free(tsk);
181}
182
183int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
184{
185	fstate_save(src, task_pt_regs(src));
186	*dst = *src;
187	/* clear entire V context, including datap for a new task */
188	memset(&dst->thread.vstate, 0, sizeof(struct __riscv_v_ext_state));
189	memset(&dst->thread.kernel_vstate, 0, sizeof(struct __riscv_v_ext_state));
190	clear_tsk_thread_flag(dst, TIF_RISCV_V_DEFER_RESTORE);
191
192	return 0;
193}
194
195int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
196{
197	unsigned long clone_flags = args->flags;
198	unsigned long usp = args->stack;
199	unsigned long tls = args->tls;
200	struct pt_regs *childregs = task_pt_regs(p);
201
202	memset(&p->thread.s, 0, sizeof(p->thread.s));
203
204	/* p->thread holds context to be restored by __switch_to() */
205	if (unlikely(args->fn)) {
206		/* Kernel thread */
207		memset(childregs, 0, sizeof(struct pt_regs));
 
208		/* Supervisor/Machine, irqs on: */
209		childregs->status = SR_PP | SR_PIE;
210
211		p->thread.s[0] = (unsigned long)args->fn;
212		p->thread.s[1] = (unsigned long)args->fn_arg;
213	} else {
214		*childregs = *(current_pt_regs());
215		/* Turn off status.VS */
216		riscv_v_vstate_off(childregs);
217		if (usp) /* User fork */
218			childregs->sp = usp;
219		if (clone_flags & CLONE_SETTLS)
220			childregs->tp = tls;
221		childregs->a0 = 0; /* Return value of fork() */
222		p->thread.s[0] = 0;
223	}
224	p->thread.riscv_v_flags = 0;
225	if (has_vector())
226		riscv_v_thread_alloc(p);
227	p->thread.ra = (unsigned long)ret_from_fork;
228	p->thread.sp = (unsigned long)childregs; /* kernel sp */
229	return 0;
230}
231
232void __init arch_task_cache_init(void)
233{
234	riscv_v_setup_ctx_cache();
235}

  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#include <asm/vector.h>
 28#include <asm/cpufeature.h>
 29
 30register unsigned long gp_in_global __asm__("gp");
 31
 32#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK)
 33#include <linux/stackprotector.h>
 34unsigned long __stack_chk_guard __read_mostly;
 35EXPORT_SYMBOL(__stack_chk_guard);
 36#endif
 37
 38extern asmlinkage void ret_from_fork(void);
 39
 40void arch_cpu_idle(void)
 41{
 42	cpu_do_idle();
 43}
 44
 45int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
 46{
 47	if (!unaligned_ctl_available())
 48		return -EINVAL;
 49
 50	tsk->thread.align_ctl = val;
 51	return 0;
 52}
 53
 54int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
 55{
 56	if (!unaligned_ctl_available())
 57		return -EINVAL;
 58
 59	return put_user(tsk->thread.align_ctl, (unsigned long __user *)adr);
 60}
 61
 62void __show_regs(struct pt_regs *regs)
 63{
 64	show_regs_print_info(KERN_DEFAULT);
 65
 66	if (!user_mode(regs)) {
 67		pr_cont("epc : %pS\n", (void *)regs->epc);
 68		pr_cont(" ra : %pS\n", (void *)regs->ra);
 69	}
 70
 71	pr_cont("epc : " REG_FMT " ra : " REG_FMT " sp : " REG_FMT "\n",
 72		regs->epc, regs->ra, regs->sp);
 73	pr_cont(" gp : " REG_FMT " tp : " REG_FMT " t0 : " REG_FMT "\n",
 74		regs->gp, regs->tp, regs->t0);
 75	pr_cont(" t1 : " REG_FMT " t2 : " REG_FMT " s0 : " REG_FMT "\n",
 76		regs->t1, regs->t2, regs->s0);
 77	pr_cont(" s1 : " REG_FMT " a0 : " REG_FMT " a1 : " REG_FMT "\n",
 78		regs->s1, regs->a0, regs->a1);
 79	pr_cont(" a2 : " REG_FMT " a3 : " REG_FMT " a4 : " REG_FMT "\n",
 80		regs->a2, regs->a3, regs->a4);
 81	pr_cont(" a5 : " REG_FMT " a6 : " REG_FMT " a7 : " REG_FMT "\n",
 82		regs->a5, regs->a6, regs->a7);
 83	pr_cont(" s2 : " REG_FMT " s3 : " REG_FMT " s4 : " REG_FMT "\n",
 84		regs->s2, regs->s3, regs->s4);
 85	pr_cont(" s5 : " REG_FMT " s6 : " REG_FMT " s7 : " REG_FMT "\n",
 86		regs->s5, regs->s6, regs->s7);
 87	pr_cont(" s8 : " REG_FMT " s9 : " REG_FMT " s10: " REG_FMT "\n",
 88		regs->s8, regs->s9, regs->s10);
 89	pr_cont(" s11: " REG_FMT " t3 : " REG_FMT " t4 : " REG_FMT "\n",
 90		regs->s11, regs->t3, regs->t4);
 91	pr_cont(" t5 : " REG_FMT " t6 : " REG_FMT "\n",
 92		regs->t5, regs->t6);
 93
 94	pr_cont("status: " REG_FMT " badaddr: " REG_FMT " cause: " REG_FMT "\n",
 95		regs->status, regs->badaddr, regs->cause);
 96}
 97void show_regs(struct pt_regs *regs)
 98{
 99	__show_regs(regs);
100	if (!user_mode(regs))
101		dump_backtrace(regs, NULL, KERN_DEFAULT);
102}
103
104#ifdef CONFIG_COMPAT
105static bool compat_mode_supported __read_mostly;
106
107bool compat_elf_check_arch(Elf32_Ehdr *hdr)
108{
109	return compat_mode_supported &&
110	       hdr->e_machine == EM_RISCV &&
111	       hdr->e_ident[EI_CLASS] == ELFCLASS32;
112}
113
114static int __init compat_mode_detect(void)
115{
116	unsigned long tmp = csr_read(CSR_STATUS);
117
118	csr_write(CSR_STATUS, (tmp & ~SR_UXL) | SR_UXL_32);
119	compat_mode_supported =
120			(csr_read(CSR_STATUS) & SR_UXL) == SR_UXL_32;
121
122	csr_write(CSR_STATUS, tmp);
123
124	pr_info("riscv: ELF compat mode %s",
125			compat_mode_supported ? "supported" : "unsupported");
126
127	return 0;
128}
129early_initcall(compat_mode_detect);
130#endif
131
132void start_thread(struct pt_regs *regs, unsigned long pc,
133	unsigned long sp)
134{
135	regs->status = SR_PIE;
136	if (has_fpu()) {
137		regs->status |= SR_FS_INITIAL;
138		/*
139		 * Restore the initial value to the FP register
140		 * before starting the user program.
141		 */
142		fstate_restore(current, regs);
143	}
144	regs->epc = pc;
145	regs->sp = sp;
146
147#ifdef CONFIG_64BIT
148	regs->status &= ~SR_UXL;
149
150	if (is_compat_task())
151		regs->status |= SR_UXL_32;
152	else
153		regs->status |= SR_UXL_64;
154#endif
155}
156
157void flush_thread(void)
158{
159#ifdef CONFIG_FPU
160	/*
161	 * Reset FPU state and context
162	 *	frm: round to nearest, ties to even (IEEE default)
163	 *	fflags: accrued exceptions cleared
164	 */
165	fstate_off(current, task_pt_regs(current));
166	memset(&current->thread.fstate, 0, sizeof(current->thread.fstate));
167#endif
168#ifdef CONFIG_RISCV_ISA_V
169	/* Reset vector state */
170	riscv_v_vstate_ctrl_init(current);
171	riscv_v_vstate_off(task_pt_regs(current));
172	kfree(current->thread.vstate.datap);
173	memset(&current->thread.vstate, 0, sizeof(struct __riscv_v_ext_state));
174	clear_tsk_thread_flag(current, TIF_RISCV_V_DEFER_RESTORE);
175#endif
176}
177
178void arch_release_task_struct(struct task_struct *tsk)
179{
180	/* Free the vector context of datap. */
181	if (has_vector())
182		riscv_v_thread_free(tsk);
183}
184
185int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
186{
187	fstate_save(src, task_pt_regs(src));
188	*dst = *src;
189	/* clear entire V context, including datap for a new task */
190	memset(&dst->thread.vstate, 0, sizeof(struct __riscv_v_ext_state));
191	memset(&dst->thread.kernel_vstate, 0, sizeof(struct __riscv_v_ext_state));
192	clear_tsk_thread_flag(dst, TIF_RISCV_V_DEFER_RESTORE);
193
194	return 0;
195}
196
197int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
198{
199	unsigned long clone_flags = args->flags;
200	unsigned long usp = args->stack;
201	unsigned long tls = args->tls;
202	struct pt_regs *childregs = task_pt_regs(p);
203
204	memset(&p->thread.s, 0, sizeof(p->thread.s));
205
206	/* p->thread holds context to be restored by __switch_to() */
207	if (unlikely(args->fn)) {
208		/* Kernel thread */
209		memset(childregs, 0, sizeof(struct pt_regs));
210		childregs->gp = gp_in_global;
211		/* Supervisor/Machine, irqs on: */
212		childregs->status = SR_PP | SR_PIE;
213
214		p->thread.s[0] = (unsigned long)args->fn;
215		p->thread.s[1] = (unsigned long)args->fn_arg;
216	} else {
217		*childregs = *(current_pt_regs());
218		/* Turn off status.VS */
219		riscv_v_vstate_off(childregs);
220		if (usp) /* User fork */
221			childregs->sp = usp;
222		if (clone_flags & CLONE_SETTLS)
223			childregs->tp = tls;
224		childregs->a0 = 0; /* Return value of fork() */
225		p->thread.s[0] = 0;
226	}
227	p->thread.riscv_v_flags = 0;
228	if (has_vector())
229		riscv_v_thread_alloc(p);
230	p->thread.ra = (unsigned long)ret_from_fork;
231	p->thread.sp = (unsigned long)childregs; /* kernel sp */
232	return 0;
233}
234
235void __init arch_task_cache_init(void)
236{
237	riscv_v_setup_ctx_cache();
238}