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 #ifdef CONFIG_CC_STACKPROTECTOR
56 #include <linux/stackprotector.h>
57 unsigned long __stack_chk_guard __read_mostly;
58 EXPORT_SYMBOL(__stack_chk_guard);
61 void soft_restart(unsigned long addr)
63 setup_mm_for_reboot();
64 cpu_soft_restart(virt_to_phys(cpu_reset), addr);
65 /* Should never get here */
70 * Function pointers to optional machine specific functions
72 void (*pm_power_off)(void);
73 EXPORT_SYMBOL_GPL(pm_power_off);
75 void (*arm_pm_restart)(char str, const char *cmd);
76 EXPORT_SYMBOL_GPL(arm_pm_restart);
78 void arch_cpu_idle_prepare(void)
84 * This is our default idle handler.
86 void arch_cpu_idle(void)
89 * This should do all the clock switching and wait for interrupt
92 if (cpuidle_idle_call()) {
98 #ifdef CONFIG_HOTPLUG_CPU
99 void arch_cpu_idle_dead(void)
105 void machine_shutdown(void)
112 void machine_halt(void)
118 void machine_power_off(void)
125 void machine_restart(char *cmd)
129 /* Disable interrupts first */
133 /* Now call the architecture specific reboot code. */
135 arm_pm_restart('h', cmd);
138 * Whoops - the architecture was unable to reboot.
140 printk("Reboot failed -- System halted\n");
145 * dump a block of kernel memory from around the given address
147 static void show_data(unsigned long addr, int nbytes, const char *name)
154 * don't attempt to dump non-kernel addresses or
155 * values that are probably just small negative numbers
157 if (addr < PAGE_OFFSET || addr > -256UL)
160 printk("\n%s: %#lx:\n", name, addr);
163 * round address down to a 32 bit boundary
164 * and always dump a multiple of 32 bytes
166 p = (u32 *)(addr & ~(sizeof(u32) - 1));
167 nbytes += (addr & (sizeof(u32) - 1));
168 nlines = (nbytes + 31) / 32;
171 for (i = 0; i < nlines; i++) {
173 * just display low 16 bits of address to keep
174 * each line of the dump < 80 characters
176 printk("%04lx ", (unsigned long)p & 0xffff);
177 for (j = 0; j < 8; j++) {
179 if (probe_kernel_address(p, data)) {
182 printk(" %08x", data);
190 static void show_extra_register_data(struct pt_regs *regs, int nbytes)
197 show_data(regs->pc - nbytes, nbytes * 2, "PC");
198 show_data(regs->regs[30] - nbytes, nbytes * 2, "LR");
199 show_data(regs->sp - nbytes, nbytes * 2, "SP");
200 for (i = 0; i < 30; i++) {
202 snprintf(name, sizeof(name), "X%u", i);
203 show_data(regs->regs[i] - nbytes, nbytes * 2, name);
208 void __show_regs(struct pt_regs *regs)
213 if (compat_user_mode(regs)) {
214 lr = regs->compat_lr;
215 sp = regs->compat_sp;
223 show_regs_print_info(KERN_DEFAULT);
224 print_symbol("PC is at %s\n", instruction_pointer(regs));
225 print_symbol("LR is at %s\n", lr);
226 printk("pc : [<%016llx>] lr : [<%016llx>] pstate: %08llx\n",
227 regs->pc, lr, regs->pstate);
228 printk("sp : %016llx\n", sp);
229 for (i = top_reg; i >= 0; i--) {
230 printk("x%-2d: %016llx ", i, regs->regs[i]);
234 if (!user_mode(regs))
235 show_extra_register_data(regs, 128);
239 void show_regs(struct pt_regs * regs)
246 * Free current thread data structures etc..
248 void exit_thread(void)
252 static void tls_thread_flush(void)
254 asm ("msr tpidr_el0, xzr");
256 if (is_compat_task()) {
257 current->thread.tp_value = 0;
260 * We need to ensure ordering between the shadow state and the
261 * hardware state, so that we don't corrupt the hardware state
262 * with a stale shadow state during context switch.
265 asm ("msr tpidrro_el0, xzr");
269 void flush_thread(void)
271 fpsimd_flush_thread();
273 flush_ptrace_hw_breakpoint(current);
276 void release_thread(struct task_struct *dead_task)
280 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
282 fpsimd_preserve_current_state();
287 asmlinkage void ret_from_fork(void) asm("ret_from_fork");
289 int copy_thread(unsigned long clone_flags, unsigned long stack_start,
290 unsigned long stk_sz, struct task_struct *p)
292 struct pt_regs *childregs = task_pt_regs(p);
293 unsigned long tls = p->thread.tp_value;
295 memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));
297 if (likely(!(p->flags & PF_KTHREAD))) {
298 *childregs = *current_pt_regs();
299 childregs->regs[0] = 0;
300 if (is_compat_thread(task_thread_info(p))) {
302 childregs->compat_sp = stack_start;
305 * Read the current TLS pointer from tpidr_el0 as it may be
306 * out-of-sync with the saved value.
308 asm("mrs %0, tpidr_el0" : "=r" (tls));
310 /* 16-byte aligned stack mandatory on AArch64 */
311 if (stack_start & 15)
313 childregs->sp = stack_start;
317 * If a TLS pointer was passed to clone (4th argument), use it
318 * for the new thread.
320 if (clone_flags & CLONE_SETTLS)
321 tls = childregs->regs[3];
323 memset(childregs, 0, sizeof(struct pt_regs));
324 childregs->pstate = PSR_MODE_EL1h;
325 p->thread.cpu_context.x19 = stack_start;
326 p->thread.cpu_context.x20 = stk_sz;
328 p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
329 p->thread.cpu_context.sp = (unsigned long)childregs;
330 p->thread.tp_value = tls;
332 ptrace_hw_copy_thread(p);
337 static void tls_thread_switch(struct task_struct *next)
339 unsigned long tpidr, tpidrro;
341 if (!is_compat_task()) {
342 asm("mrs %0, tpidr_el0" : "=r" (tpidr));
343 current->thread.tp_value = tpidr;
346 if (is_compat_thread(task_thread_info(next))) {
348 tpidrro = next->thread.tp_value;
350 tpidr = next->thread.tp_value;
355 " msr tpidr_el0, %0\n"
356 " msr tpidrro_el0, %1"
357 : : "r" (tpidr), "r" (tpidrro));
363 struct task_struct *__switch_to(struct task_struct *prev,
364 struct task_struct *next)
366 struct task_struct *last;
368 fpsimd_thread_switch(next);
369 tls_thread_switch(next);
370 hw_breakpoint_thread_switch(next);
371 contextidr_thread_switch(next);
374 * Complete any pending TLB or cache maintenance on this CPU in case
375 * the thread migrates to a different CPU.
379 /* the actual thread switch */
380 last = cpu_switch_to(prev, next);
385 unsigned long get_wchan(struct task_struct *p)
387 struct stackframe frame;
388 unsigned long stack_page;
390 if (!p || p == current || p->state == TASK_RUNNING)
393 frame.fp = thread_saved_fp(p);
394 frame.sp = thread_saved_sp(p);
395 frame.pc = thread_saved_pc(p);
396 stack_page = (unsigned long)task_stack_page(p);
398 if (frame.sp < stack_page ||
399 frame.sp >= stack_page + THREAD_SIZE ||
400 unwind_frame(&frame))
402 if (!in_sched_functions(frame.pc))
404 } while (count ++ < 16);
408 unsigned long arch_align_stack(unsigned long sp)
410 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
411 sp -= get_random_int() & ~PAGE_MASK;
415 static unsigned long randomize_base(unsigned long base)
417 unsigned long range_end = base + (STACK_RND_MASK << PAGE_SHIFT) + 1;
418 return randomize_range(base, range_end, 0) ? : base;
421 unsigned long arch_randomize_brk(struct mm_struct *mm)
423 return randomize_base(mm->brk);
426 unsigned long randomize_et_dyn(unsigned long base)
428 return randomize_base(base);
431 void arch_cpu_idle_enter(void)
433 idle_notifier_call_chain(IDLE_START);
436 void arch_cpu_idle_exit(void)
438 idle_notifier_call_chain(IDLE_END);