Loading...
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// 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 pr_info("\n");
34 show_regs_print_info(KERN_DEFAULT);
35
36 pr_info("PC is at %pS\n", (void *)instruction_pointer(regs));
37 pr_info("PR is at %pS\n", (void *)regs->pr);
38
39 pr_info("PC : %08lx SP : %08lx SR : %08lx ", regs->pc,
40 regs->regs[15], regs->sr);
41#ifdef CONFIG_MMU
42 pr_cont("TEA : %08x\n", __raw_readl(MMU_TEA));
43#else
44 pr_cont("\n");
45#endif
46
47 pr_info("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
48 regs->regs[0], regs->regs[1], regs->regs[2], regs->regs[3]);
49 pr_info("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
50 regs->regs[4], regs->regs[5], regs->regs[6], regs->regs[7]);
51 pr_info("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
52 regs->regs[8], regs->regs[9], regs->regs[10], regs->regs[11]);
53 pr_info("R12 : %08lx R13 : %08lx R14 : %08lx\n",
54 regs->regs[12], regs->regs[13], regs->regs[14]);
55 pr_info("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
56 regs->mach, regs->macl, regs->gbr, regs->pr);
57
58 show_trace(NULL, (unsigned long *)regs->regs[15], regs, KERN_DEFAULT);
59 show_code(regs);
60}
61
62void start_thread(struct pt_regs *regs, unsigned long new_pc,
63 unsigned long new_sp)
64{
65 regs->pr = 0;
66 regs->sr = SR_FD;
67 regs->pc = new_pc;
68 regs->regs[15] = new_sp;
69
70 free_thread_xstate(current);
71}
72EXPORT_SYMBOL(start_thread);
73
74void flush_thread(void)
75{
76 struct task_struct *tsk = current;
77
78 flush_ptrace_hw_breakpoint(tsk);
79
80#if defined(CONFIG_SH_FPU)
81 /* Forget lazy FPU state */
82 clear_fpu(tsk, task_pt_regs(tsk));
83 clear_used_math();
84#endif
85}
86
87void release_thread(struct task_struct *dead_task)
88{
89 /* do nothing */
90}
91
92asmlinkage void ret_from_fork(void);
93asmlinkage void ret_from_kernel_thread(void);
94
95int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
96 struct task_struct *p, unsigned long tls)
97{
98 struct thread_info *ti = task_thread_info(p);
99 struct pt_regs *childregs;
100
101#if defined(CONFIG_SH_DSP)
102 struct task_struct *tsk = current;
103
104 if (is_dsp_enabled(tsk)) {
105 /* We can use the __save_dsp or just copy the struct:
106 * __save_dsp(p);
107 * p->thread.dsp_status.status |= SR_DSP
108 */
109 p->thread.dsp_status = tsk->thread.dsp_status;
110 }
111#endif
112
113 memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
114
115 childregs = task_pt_regs(p);
116 p->thread.sp = (unsigned long) childregs;
117 if (unlikely(p->flags & PF_KTHREAD)) {
118 memset(childregs, 0, sizeof(struct pt_regs));
119 p->thread.pc = (unsigned long) ret_from_kernel_thread;
120 childregs->regs[4] = arg;
121 childregs->regs[5] = usp;
122 childregs->sr = SR_MD;
123#if defined(CONFIG_SH_FPU)
124 childregs->sr |= SR_FD;
125#endif
126 ti->addr_limit = KERNEL_DS;
127 ti->status &= ~TS_USEDFPU;
128 p->thread.fpu_counter = 0;
129 return 0;
130 }
131 *childregs = *current_pt_regs();
132
133 if (usp)
134 childregs->regs[15] = usp;
135 ti->addr_limit = USER_DS;
136
137 if (clone_flags & CLONE_SETTLS)
138 childregs->gbr = tls;
139
140 childregs->regs[0] = 0; /* Set return value for child */
141 p->thread.pc = (unsigned long) ret_from_fork;
142 return 0;
143}
144
145/*
146 * switch_to(x,y) should switch tasks from x to y.
147 *
148 */
149__notrace_funcgraph struct task_struct *
150__switch_to(struct task_struct *prev, struct task_struct *next)
151{
152 struct thread_struct *next_t = &next->thread;
153
154#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
155 __stack_chk_guard = next->stack_canary;
156#endif
157
158 unlazy_fpu(prev, task_pt_regs(prev));
159
160 /* we're going to use this soon, after a few expensive things */
161 if (next->thread.fpu_counter > 5)
162 prefetch(next_t->xstate);
163
164#ifdef CONFIG_MMU
165 /*
166 * Restore the kernel mode register
167 * k7 (r7_bank1)
168 */
169 asm volatile("ldc %0, r7_bank"
170 : /* no output */
171 : "r" (task_thread_info(next)));
172#endif
173
174 /*
175 * If the task has used fpu the last 5 timeslices, just do a full
176 * restore of the math state immediately to avoid the trap; the
177 * chances of needing FPU soon are obviously high now
178 */
179 if (next->thread.fpu_counter > 5)
180 __fpu_state_restore();
181
182 return prev;
183}
184
185unsigned long get_wchan(struct task_struct *p)
186{
187 unsigned long pc;
188
189 if (!p || p == current || p->state == TASK_RUNNING)
190 return 0;
191
192 /*
193 * The same comment as on the Alpha applies here, too ...
194 */
195 pc = thread_saved_pc(p);
196
197#ifdef CONFIG_FRAME_POINTER
198 if (in_sched_functions(pc)) {
199 unsigned long schedule_frame = (unsigned long)p->thread.sp;
200 return ((unsigned long *)schedule_frame)[21];
201 }
202#endif
203
204 return pc;
205}