]>
git.ipfire.org Git - thirdparty/kernel/stable.git/blob - arch/arm64/kernel/process.c
2 * Based on arch/arm/kernel/process.c
4 * Original Copyright (C) 1995 Linus Torvalds
5 * Copyright (C) 1996-2000 Russell King - Converted to ARM.
6 * Copyright (C) 2012 ARM Ltd.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
23 #include <linux/export.h>
24 #include <linux/sched.h>
25 #include <linux/kernel.h>
27 #include <linux/stddef.h>
28 #include <linux/unistd.h>
29 #include <linux/user.h>
30 #include <linux/delay.h>
31 #include <linux/reboot.h>
32 #include <linux/interrupt.h>
33 #include <linux/kallsyms.h>
34 #include <linux/init.h>
35 #include <linux/cpu.h>
36 #include <linux/elfcore.h>
38 #include <linux/tick.h>
39 #include <linux/utsname.h>
40 #include <linux/uaccess.h>
41 #include <linux/random.h>
42 #include <linux/hw_breakpoint.h>
43 #include <linux/personality.h>
44 #include <linux/notifier.h>
46 #include <asm/compat.h>
47 #include <asm/cacheflush.h>
48 #include <asm/fpsimd.h>
49 #include <asm/mmu_context.h>
50 #include <asm/processor.h>
51 #include <asm/stacktrace.h>
53 static void setup_restart(void)
56 * Tell the mm system that we are going to reboot -
57 * we may need it to insert some 1:1 mappings so that
60 setup_mm_for_reboot();
62 /* Clean and invalidate caches */
65 /* Turn D-cache off */
68 /* Push out any further dirty data, and ensure cache is empty */
72 void soft_restart(unsigned long addr
)
74 typedef void (*phys_reset_t
)(unsigned long);
75 phys_reset_t phys_reset
;
79 /* Switch to the identity mapping */
80 phys_reset
= (phys_reset_t
)virt_to_phys(cpu_reset
);
83 /* Should never get here */
88 * Function pointers to optional machine specific functions
90 void (*pm_power_off
)(void);
91 EXPORT_SYMBOL_GPL(pm_power_off
);
93 void (*arm_pm_restart
)(enum reboot_mode reboot_mode
, const char *cmd
);
94 EXPORT_SYMBOL_GPL(arm_pm_restart
);
97 * This is our default idle handler.
99 void arch_cpu_idle(void)
102 * This should do all the clock switching and wait for interrupt
109 #ifdef CONFIG_HOTPLUG_CPU
110 void arch_cpu_idle_dead(void)
116 void machine_shutdown(void)
123 void machine_halt(void)
129 void machine_power_off(void)
136 void machine_restart(char *cmd
)
140 /* Disable interrupts first */
143 /* Now call the architecture specific reboot code. */
145 arm_pm_restart(reboot_mode
, cmd
);
148 * Whoops - the architecture was unable to reboot.
150 printk("Reboot failed -- System halted\n");
154 void __show_regs(struct pt_regs
*regs
)
159 if (compat_user_mode(regs
)) {
160 lr
= regs
->compat_lr
;
161 sp
= regs
->compat_sp
;
169 show_regs_print_info(KERN_DEFAULT
);
170 print_symbol("PC is at %s\n", instruction_pointer(regs
));
171 print_symbol("LR is at %s\n", lr
);
172 printk("pc : [<%016llx>] lr : [<%016llx>] pstate: %08llx\n",
173 regs
->pc
, lr
, regs
->pstate
);
174 printk("sp : %016llx\n", sp
);
175 for (i
= top_reg
; i
>= 0; i
--) {
176 printk("x%-2d: %016llx ", i
, regs
->regs
[i
]);
183 void show_regs(struct pt_regs
* regs
)
190 * Free current thread data structures etc..
192 void exit_thread(void)
196 void flush_thread(void)
198 fpsimd_flush_thread();
199 flush_ptrace_hw_breakpoint(current
);
202 void release_thread(struct task_struct
*dead_task
)
206 int arch_dup_task_struct(struct task_struct
*dst
, struct task_struct
*src
)
208 fpsimd_save_state(¤t
->thread
.fpsimd_state
);
213 asmlinkage
void ret_from_fork(void) asm("ret_from_fork");
215 int copy_thread(unsigned long clone_flags
, unsigned long stack_start
,
216 unsigned long stk_sz
, struct task_struct
*p
)
218 struct pt_regs
*childregs
= task_pt_regs(p
);
219 unsigned long tls
= p
->thread
.tp_value
;
221 memset(&p
->thread
.cpu_context
, 0, sizeof(struct cpu_context
));
223 if (likely(!(p
->flags
& PF_KTHREAD
))) {
224 *childregs
= *current_pt_regs();
225 childregs
->regs
[0] = 0;
226 if (is_compat_thread(task_thread_info(p
))) {
228 childregs
->compat_sp
= stack_start
;
231 * Read the current TLS pointer from tpidr_el0 as it may be
232 * out-of-sync with the saved value.
234 asm("mrs %0, tpidr_el0" : "=r" (tls
));
236 /* 16-byte aligned stack mandatory on AArch64 */
237 if (stack_start
& 15)
239 childregs
->sp
= stack_start
;
243 * If a TLS pointer was passed to clone (4th argument), use it
244 * for the new thread.
246 if (clone_flags
& CLONE_SETTLS
)
247 tls
= childregs
->regs
[3];
249 memset(childregs
, 0, sizeof(struct pt_regs
));
250 childregs
->pstate
= PSR_MODE_EL1h
;
251 p
->thread
.cpu_context
.x19
= stack_start
;
252 p
->thread
.cpu_context
.x20
= stk_sz
;
254 p
->thread
.cpu_context
.pc
= (unsigned long)ret_from_fork
;
255 p
->thread
.cpu_context
.sp
= (unsigned long)childregs
;
256 p
->thread
.tp_value
= tls
;
258 ptrace_hw_copy_thread(p
);
263 static void tls_thread_switch(struct task_struct
*next
)
265 unsigned long tpidr
, tpidrro
;
267 if (!is_compat_task()) {
268 asm("mrs %0, tpidr_el0" : "=r" (tpidr
));
269 current
->thread
.tp_value
= tpidr
;
272 if (is_compat_thread(task_thread_info(next
))) {
274 tpidrro
= next
->thread
.tp_value
;
276 tpidr
= next
->thread
.tp_value
;
281 " msr tpidr_el0, %0\n"
282 " msr tpidrro_el0, %1"
283 : : "r" (tpidr
), "r" (tpidrro
));
289 struct task_struct
*__switch_to(struct task_struct
*prev
,
290 struct task_struct
*next
)
292 struct task_struct
*last
;
294 fpsimd_thread_switch(next
);
295 tls_thread_switch(next
);
296 hw_breakpoint_thread_switch(next
);
297 contextidr_thread_switch(next
);
300 * Complete any pending TLB or cache maintenance on this CPU in case
301 * the thread migrates to a different CPU.
305 /* the actual thread switch */
306 last
= cpu_switch_to(prev
, next
);
311 unsigned long get_wchan(struct task_struct
*p
)
313 struct stackframe frame
;
314 unsigned long stack_page
;
316 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
)
319 frame
.fp
= thread_saved_fp(p
);
320 frame
.sp
= thread_saved_sp(p
);
321 frame
.pc
= thread_saved_pc(p
);
322 stack_page
= (unsigned long)task_stack_page(p
);
324 if (frame
.sp
< stack_page
||
325 frame
.sp
>= stack_page
+ THREAD_SIZE
||
326 unwind_frame(&frame
))
328 if (!in_sched_functions(frame
.pc
))
330 } while (count
++ < 16);
334 unsigned long arch_align_stack(unsigned long sp
)
336 if (!(current
->personality
& ADDR_NO_RANDOMIZE
) && randomize_va_space
)
337 sp
-= get_random_int() & ~PAGE_MASK
;
341 static unsigned long randomize_base(unsigned long base
)
343 unsigned long range_end
= base
+ (STACK_RND_MASK
<< PAGE_SHIFT
) + 1;
344 return randomize_range(base
, range_end
, 0) ? : base
;
347 unsigned long arch_randomize_brk(struct mm_struct
*mm
)
349 return randomize_base(mm
->brk
);
352 unsigned long randomize_et_dyn(unsigned long base
)
354 return randomize_base(base
);