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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * arch/sh/kernel/process.c
4 *
5 * This file handles the architecture-dependent parts of process handling..
6 *
7 * Copyright (C) 1995 Linus Torvalds
8 *
9 * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
10 * Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC
11 * Copyright (C) 2002 - 2008 Paul Mundt
12 */
13#include <linux/module.h>
14#include <linux/mm.h>
15#include <linux/sched/debug.h>
16#include <linux/sched/task.h>
17#include <linux/sched/task_stack.h>
18#include <linux/slab.h>
19#include <linux/elfcore.h>
20#include <linux/fs.h>
21#include <linux/ftrace.h>
22#include <linux/hw_breakpoint.h>
23#include <linux/prefetch.h>
24#include <linux/stackprotector.h>
25#include <linux/uaccess.h>
26#include <asm/mmu_context.h>
27#include <asm/fpu.h>
28#include <asm/syscalls.h>
29#include <asm/switch_to.h>
30
31void show_regs(struct pt_regs * regs)
32{
33 printk("\n");
34 show_regs_print_info(KERN_DEFAULT);
35
36 printk("PC is at %pS\n", (void *)instruction_pointer(regs));
37 printk("PR is at %pS\n", (void *)regs->pr);
38
39 printk("PC : %08lx SP : %08lx SR : %08lx ",
40 regs->pc, regs->regs[15], regs->sr);
41#ifdef CONFIG_MMU
42 printk("TEA : %08x\n", __raw_readl(MMU_TEA));
43#else
44 printk("\n");
45#endif
46
47 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
48 regs->regs[0],regs->regs[1],
49 regs->regs[2],regs->regs[3]);
50 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
51 regs->regs[4],regs->regs[5],
52 regs->regs[6],regs->regs[7]);
53 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
54 regs->regs[8],regs->regs[9],
55 regs->regs[10],regs->regs[11]);
56 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
57 regs->regs[12],regs->regs[13],
58 regs->regs[14]);
59 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
60 regs->mach, regs->macl, regs->gbr, regs->pr);
61
62 show_trace(NULL, (unsigned long *)regs->regs[15], regs);
63 show_code(regs);
64}
65
66void start_thread(struct pt_regs *regs, unsigned long new_pc,
67 unsigned long new_sp)
68{
69 regs->pr = 0;
70 regs->sr = SR_FD;
71 regs->pc = new_pc;
72 regs->regs[15] = new_sp;
73
74 free_thread_xstate(current);
75}
76EXPORT_SYMBOL(start_thread);
77
78void flush_thread(void)
79{
80 struct task_struct *tsk = current;
81
82 flush_ptrace_hw_breakpoint(tsk);
83
84#if defined(CONFIG_SH_FPU)
85 /* Forget lazy FPU state */
86 clear_fpu(tsk, task_pt_regs(tsk));
87 clear_used_math();
88#endif
89}
90
91void release_thread(struct task_struct *dead_task)
92{
93 /* do nothing */
94}
95
96/* Fill in the fpu structure for a core dump.. */
97int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
98{
99 int fpvalid = 0;
100
101#if defined(CONFIG_SH_FPU)
102 struct task_struct *tsk = current;
103
104 fpvalid = !!tsk_used_math(tsk);
105 if (fpvalid)
106 fpvalid = !fpregs_get(tsk, NULL, 0,
107 sizeof(struct user_fpu_struct),
108 fpu, NULL);
109#endif
110
111 return fpvalid;
112}
113EXPORT_SYMBOL(dump_fpu);
114
115asmlinkage void ret_from_fork(void);
116asmlinkage void ret_from_kernel_thread(void);
117
118int copy_thread(unsigned long clone_flags, unsigned long usp,
119 unsigned long arg, struct task_struct *p)
120{
121 struct thread_info *ti = task_thread_info(p);
122 struct pt_regs *childregs;
123
124#if defined(CONFIG_SH_DSP)
125 struct task_struct *tsk = current;
126
127 if (is_dsp_enabled(tsk)) {
128 /* We can use the __save_dsp or just copy the struct:
129 * __save_dsp(p);
130 * p->thread.dsp_status.status |= SR_DSP
131 */
132 p->thread.dsp_status = tsk->thread.dsp_status;
133 }
134#endif
135
136 memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
137
138 childregs = task_pt_regs(p);
139 p->thread.sp = (unsigned long) childregs;
140 if (unlikely(p->flags & PF_KTHREAD)) {
141 memset(childregs, 0, sizeof(struct pt_regs));
142 p->thread.pc = (unsigned long) ret_from_kernel_thread;
143 childregs->regs[4] = arg;
144 childregs->regs[5] = usp;
145 childregs->sr = SR_MD;
146#if defined(CONFIG_SH_FPU)
147 childregs->sr |= SR_FD;
148#endif
149 ti->addr_limit = KERNEL_DS;
150 ti->status &= ~TS_USEDFPU;
151 p->thread.fpu_counter = 0;
152 return 0;
153 }
154 *childregs = *current_pt_regs();
155
156 if (usp)
157 childregs->regs[15] = usp;
158 ti->addr_limit = USER_DS;
159
160 if (clone_flags & CLONE_SETTLS)
161 childregs->gbr = childregs->regs[0];
162
163 childregs->regs[0] = 0; /* Set return value for child */
164 p->thread.pc = (unsigned long) ret_from_fork;
165 return 0;
166}
167
168/*
169 * switch_to(x,y) should switch tasks from x to y.
170 *
171 */
172__notrace_funcgraph struct task_struct *
173__switch_to(struct task_struct *prev, struct task_struct *next)
174{
175 struct thread_struct *next_t = &next->thread;
176
177#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
178 __stack_chk_guard = next->stack_canary;
179#endif
180
181 unlazy_fpu(prev, task_pt_regs(prev));
182
183 /* we're going to use this soon, after a few expensive things */
184 if (next->thread.fpu_counter > 5)
185 prefetch(next_t->xstate);
186
187#ifdef CONFIG_MMU
188 /*
189 * Restore the kernel mode register
190 * k7 (r7_bank1)
191 */
192 asm volatile("ldc %0, r7_bank"
193 : /* no output */
194 : "r" (task_thread_info(next)));
195#endif
196
197 /*
198 * If the task has used fpu the last 5 timeslices, just do a full
199 * restore of the math state immediately to avoid the trap; the
200 * chances of needing FPU soon are obviously high now
201 */
202 if (next->thread.fpu_counter > 5)
203 __fpu_state_restore();
204
205 return prev;
206}
207
208unsigned long get_wchan(struct task_struct *p)
209{
210 unsigned long pc;
211
212 if (!p || p == current || p->state == TASK_RUNNING)
213 return 0;
214
215 /*
216 * The same comment as on the Alpha applies here, too ...
217 */
218 pc = thread_saved_pc(p);
219
220#ifdef CONFIG_FRAME_POINTER
221 if (in_sched_functions(pc)) {
222 unsigned long schedule_frame = (unsigned long)p->thread.sp;
223 return ((unsigned long *)schedule_frame)[21];
224 }
225#endif
226
227 return pc;
228}
1/*
2 * arch/sh/kernel/process.c
3 *
4 * This file handles the architecture-dependent parts of process handling..
5 *
6 * Copyright (C) 1995 Linus Torvalds
7 *
8 * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
9 * Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC
10 * Copyright (C) 2002 - 2008 Paul Mundt
11 *
12 * This file is subject to the terms and conditions of the GNU General Public
13 * License. See the file "COPYING" in the main directory of this archive
14 * for more details.
15 */
16#include <linux/module.h>
17#include <linux/mm.h>
18#include <linux/sched/debug.h>
19#include <linux/sched/task.h>
20#include <linux/sched/task_stack.h>
21#include <linux/slab.h>
22#include <linux/elfcore.h>
23#include <linux/fs.h>
24#include <linux/ftrace.h>
25#include <linux/hw_breakpoint.h>
26#include <linux/prefetch.h>
27#include <linux/stackprotector.h>
28#include <linux/uaccess.h>
29#include <asm/mmu_context.h>
30#include <asm/fpu.h>
31#include <asm/syscalls.h>
32#include <asm/switch_to.h>
33
34void show_regs(struct pt_regs * regs)
35{
36 printk("\n");
37 show_regs_print_info(KERN_DEFAULT);
38
39 printk("PC is at %pS\n", (void *)instruction_pointer(regs));
40 printk("PR is at %pS\n", (void *)regs->pr);
41
42 printk("PC : %08lx SP : %08lx SR : %08lx ",
43 regs->pc, regs->regs[15], regs->sr);
44#ifdef CONFIG_MMU
45 printk("TEA : %08x\n", __raw_readl(MMU_TEA));
46#else
47 printk("\n");
48#endif
49
50 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
51 regs->regs[0],regs->regs[1],
52 regs->regs[2],regs->regs[3]);
53 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
54 regs->regs[4],regs->regs[5],
55 regs->regs[6],regs->regs[7]);
56 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
57 regs->regs[8],regs->regs[9],
58 regs->regs[10],regs->regs[11]);
59 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
60 regs->regs[12],regs->regs[13],
61 regs->regs[14]);
62 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
63 regs->mach, regs->macl, regs->gbr, regs->pr);
64
65 show_trace(NULL, (unsigned long *)regs->regs[15], regs);
66 show_code(regs);
67}
68
69void start_thread(struct pt_regs *regs, unsigned long new_pc,
70 unsigned long new_sp)
71{
72 regs->pr = 0;
73 regs->sr = SR_FD;
74 regs->pc = new_pc;
75 regs->regs[15] = new_sp;
76
77 free_thread_xstate(current);
78}
79EXPORT_SYMBOL(start_thread);
80
81void flush_thread(void)
82{
83 struct task_struct *tsk = current;
84
85 flush_ptrace_hw_breakpoint(tsk);
86
87#if defined(CONFIG_SH_FPU)
88 /* Forget lazy FPU state */
89 clear_fpu(tsk, task_pt_regs(tsk));
90 clear_used_math();
91#endif
92}
93
94void release_thread(struct task_struct *dead_task)
95{
96 /* do nothing */
97}
98
99/* Fill in the fpu structure for a core dump.. */
100int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
101{
102 int fpvalid = 0;
103
104#if defined(CONFIG_SH_FPU)
105 struct task_struct *tsk = current;
106
107 fpvalid = !!tsk_used_math(tsk);
108 if (fpvalid)
109 fpvalid = !fpregs_get(tsk, NULL, 0,
110 sizeof(struct user_fpu_struct),
111 fpu, NULL);
112#endif
113
114 return fpvalid;
115}
116EXPORT_SYMBOL(dump_fpu);
117
118asmlinkage void ret_from_fork(void);
119asmlinkage void ret_from_kernel_thread(void);
120
121int copy_thread(unsigned long clone_flags, unsigned long usp,
122 unsigned long arg, struct task_struct *p)
123{
124 struct thread_info *ti = task_thread_info(p);
125 struct pt_regs *childregs;
126
127#if defined(CONFIG_SH_DSP)
128 struct task_struct *tsk = current;
129
130 if (is_dsp_enabled(tsk)) {
131 /* We can use the __save_dsp or just copy the struct:
132 * __save_dsp(p);
133 * p->thread.dsp_status.status |= SR_DSP
134 */
135 p->thread.dsp_status = tsk->thread.dsp_status;
136 }
137#endif
138
139 memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
140
141 childregs = task_pt_regs(p);
142 p->thread.sp = (unsigned long) childregs;
143 if (unlikely(p->flags & PF_KTHREAD)) {
144 memset(childregs, 0, sizeof(struct pt_regs));
145 p->thread.pc = (unsigned long) ret_from_kernel_thread;
146 childregs->regs[4] = arg;
147 childregs->regs[5] = usp;
148 childregs->sr = SR_MD;
149#if defined(CONFIG_SH_FPU)
150 childregs->sr |= SR_FD;
151#endif
152 ti->addr_limit = KERNEL_DS;
153 ti->status &= ~TS_USEDFPU;
154 p->thread.fpu_counter = 0;
155 return 0;
156 }
157 *childregs = *current_pt_regs();
158
159 if (usp)
160 childregs->regs[15] = usp;
161 ti->addr_limit = USER_DS;
162
163 if (clone_flags & CLONE_SETTLS)
164 childregs->gbr = childregs->regs[0];
165
166 childregs->regs[0] = 0; /* Set return value for child */
167 p->thread.pc = (unsigned long) ret_from_fork;
168 return 0;
169}
170
171/*
172 * switch_to(x,y) should switch tasks from x to y.
173 *
174 */
175__notrace_funcgraph struct task_struct *
176__switch_to(struct task_struct *prev, struct task_struct *next)
177{
178 struct thread_struct *next_t = &next->thread;
179
180#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
181 __stack_chk_guard = next->stack_canary;
182#endif
183
184 unlazy_fpu(prev, task_pt_regs(prev));
185
186 /* we're going to use this soon, after a few expensive things */
187 if (next->thread.fpu_counter > 5)
188 prefetch(next_t->xstate);
189
190#ifdef CONFIG_MMU
191 /*
192 * Restore the kernel mode register
193 * k7 (r7_bank1)
194 */
195 asm volatile("ldc %0, r7_bank"
196 : /* no output */
197 : "r" (task_thread_info(next)));
198#endif
199
200 /*
201 * If the task has used fpu the last 5 timeslices, just do a full
202 * restore of the math state immediately to avoid the trap; the
203 * chances of needing FPU soon are obviously high now
204 */
205 if (next->thread.fpu_counter > 5)
206 __fpu_state_restore();
207
208 return prev;
209}
210
211unsigned long get_wchan(struct task_struct *p)
212{
213 unsigned long pc;
214
215 if (!p || p == current || p->state == TASK_RUNNING)
216 return 0;
217
218 /*
219 * The same comment as on the Alpha applies here, too ...
220 */
221 pc = thread_saved_pc(p);
222
223#ifdef CONFIG_FRAME_POINTER
224 if (in_sched_functions(pc)) {
225 unsigned long schedule_frame = (unsigned long)p->thread.sp;
226 return ((unsigned long *)schedule_frame)[21];
227 }
228#endif
229
230 return pc;
231}