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/compat.h>
24 #include <linux/export.h>
25 #include <linux/sched.h>
26 #include <linux/kernel.h>
28 #include <linux/stddef.h>
29 #include <linux/unistd.h>
30 #include <linux/user.h>
31 #include <linux/delay.h>
32 #include <linux/reboot.h>
33 #include <linux/interrupt.h>
34 #include <linux/kallsyms.h>
35 #include <linux/init.h>
36 #include <linux/cpu.h>
37 #include <linux/cpuidle.h>
38 #include <linux/elfcore.h>
40 #include <linux/tick.h>
41 #include <linux/utsname.h>
42 #include <linux/uaccess.h>
43 #include <linux/random.h>
44 #include <linux/hw_breakpoint.h>
45 #include <linux/personality.h>
46 #include <linux/notifier.h>
48 #include <asm/compat.h>
49 #include <asm/cacheflush.h>
50 #include <asm/fpsimd.h>
51 #include <asm/mmu_context.h>
52 #include <asm/processor.h>
53 #include <asm/stacktrace.h>
55 static void setup_restart(void)
58 * Tell the mm system that we are going to reboot -
59 * we may need it to insert some 1:1 mappings so that
62 setup_mm_for_reboot();
64 /* Clean and invalidate caches */
67 /* Turn D-cache off */
70 /* Push out any further dirty data, and ensure cache is empty */
74 void soft_restart(unsigned long addr)
76 typedef void (*phys_reset_t)(unsigned long);
77 phys_reset_t phys_reset;
81 /* Switch to the identity mapping */
82 phys_reset = (phys_reset_t)virt_to_phys(cpu_reset);
85 /* Should never get here */
90 * Function pointers to optional machine specific functions
92 void (*pm_power_off)(void);
93 EXPORT_SYMBOL_GPL(pm_power_off);
95 void (*arm_pm_restart)(char str, const char *cmd);
96 EXPORT_SYMBOL_GPL(arm_pm_restart);
98 void arch_cpu_idle_prepare(void)
104 * This is our default idle handler.
106 void arch_cpu_idle(void)
109 * This should do all the clock switching and wait for interrupt
112 if (cpuidle_idle_call()) {
118 #ifdef CONFIG_HOTPLUG_CPU
119 void arch_cpu_idle_dead(void)
125 void machine_shutdown(void)
132 void machine_halt(void)
138 void machine_power_off(void)
145 void machine_restart(char *cmd)
149 /* Disable interrupts first */
153 /* Now call the architecture specific reboot code. */
155 arm_pm_restart('h', cmd);
158 * Whoops - the architecture was unable to reboot.
160 printk("Reboot failed -- System halted\n");
164 void __show_regs(struct pt_regs *regs)
169 if (compat_user_mode(regs)) {
170 lr = regs->compat_lr;
171 sp = regs->compat_sp;
179 show_regs_print_info(KERN_DEFAULT);
180 print_symbol("PC is at %s\n", instruction_pointer(regs));
181 print_symbol("LR is at %s\n", lr);
182 printk("pc : [<%016llx>] lr : [<%016llx>] pstate: %08llx\n",
183 regs->pc, lr, regs->pstate);
184 printk("sp : %016llx\n", sp);
185 for (i = top_reg; i >= 0; i--) {
186 printk("x%-2d: %016llx ", i, regs->regs[i]);
193 void show_regs(struct pt_regs * regs)
200 * Free current thread data structures etc..
202 void exit_thread(void)
206 static void tls_thread_flush(void)
208 asm ("msr tpidr_el0, xzr");
210 if (is_compat_task()) {
211 current->thread.tp_value = 0;
214 * We need to ensure ordering between the shadow state and the
215 * hardware state, so that we don't corrupt the hardware state
216 * with a stale shadow state during context switch.
219 asm ("msr tpidrro_el0, xzr");
223 void flush_thread(void)
225 fpsimd_flush_thread();
227 flush_ptrace_hw_breakpoint(current);
230 void release_thread(struct task_struct *dead_task)
234 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
236 fpsimd_save_state(¤t->thread.fpsimd_state);
241 asmlinkage void ret_from_fork(void) asm("ret_from_fork");
243 int copy_thread(unsigned long clone_flags, unsigned long stack_start,
244 unsigned long stk_sz, struct task_struct *p)
246 struct pt_regs *childregs = task_pt_regs(p);
247 unsigned long tls = p->thread.tp_value;
249 memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));
251 if (likely(!(p->flags & PF_KTHREAD))) {
252 *childregs = *current_pt_regs();
253 childregs->regs[0] = 0;
254 if (is_compat_thread(task_thread_info(p))) {
256 childregs->compat_sp = stack_start;
259 * Read the current TLS pointer from tpidr_el0 as it may be
260 * out-of-sync with the saved value.
262 asm("mrs %0, tpidr_el0" : "=r" (tls));
264 /* 16-byte aligned stack mandatory on AArch64 */
265 if (stack_start & 15)
267 childregs->sp = stack_start;
271 * If a TLS pointer was passed to clone (4th argument), use it
272 * for the new thread.
274 if (clone_flags & CLONE_SETTLS)
275 tls = childregs->regs[3];
277 memset(childregs, 0, sizeof(struct pt_regs));
278 childregs->pstate = PSR_MODE_EL1h;
279 p->thread.cpu_context.x19 = stack_start;
280 p->thread.cpu_context.x20 = stk_sz;
282 p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
283 p->thread.cpu_context.sp = (unsigned long)childregs;
284 p->thread.tp_value = tls;
286 ptrace_hw_copy_thread(p);
291 static void tls_thread_switch(struct task_struct *next)
293 unsigned long tpidr, tpidrro;
295 if (!is_compat_task()) {
296 asm("mrs %0, tpidr_el0" : "=r" (tpidr));
297 current->thread.tp_value = tpidr;
300 if (is_compat_thread(task_thread_info(next))) {
302 tpidrro = next->thread.tp_value;
304 tpidr = next->thread.tp_value;
309 " msr tpidr_el0, %0\n"
310 " msr tpidrro_el0, %1"
311 : : "r" (tpidr), "r" (tpidrro));
317 struct task_struct *__switch_to(struct task_struct *prev,
318 struct task_struct *next)
320 struct task_struct *last;
322 fpsimd_thread_switch(next);
323 tls_thread_switch(next);
324 hw_breakpoint_thread_switch(next);
325 contextidr_thread_switch(next);
328 * Complete any pending TLB or cache maintenance on this CPU in case
329 * the thread migrates to a different CPU.
333 /* the actual thread switch */
334 last = cpu_switch_to(prev, next);
339 unsigned long get_wchan(struct task_struct *p)
341 struct stackframe frame;
342 unsigned long stack_page;
344 if (!p || p == current || p->state == TASK_RUNNING)
347 frame.fp = thread_saved_fp(p);
348 frame.sp = thread_saved_sp(p);
349 frame.pc = thread_saved_pc(p);
350 stack_page = (unsigned long)task_stack_page(p);
352 if (frame.sp < stack_page ||
353 frame.sp >= stack_page + THREAD_SIZE ||
354 unwind_frame(&frame))
356 if (!in_sched_functions(frame.pc))
358 } while (count ++ < 16);
362 unsigned long arch_align_stack(unsigned long sp)
364 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
365 sp -= get_random_int() & ~PAGE_MASK;
369 static unsigned long randomize_base(unsigned long base)
371 unsigned long range_end = base + (STACK_RND_MASK << PAGE_SHIFT) + 1;
372 return randomize_range(base, range_end, 0) ? : base;
375 unsigned long arch_randomize_brk(struct mm_struct *mm)
377 return randomize_base(mm->brk);
380 unsigned long randomize_et_dyn(unsigned long base)
382 return randomize_base(base);