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);