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)
79 * Function pointers to optional machine specific functions
81 void (*pm_power_off)(void);
82 EXPORT_SYMBOL_GPL(pm_power_off);
84 void (*arm_pm_restart)(char str, const char *cmd);
85 EXPORT_SYMBOL_GPL(arm_pm_restart);
87 void arch_cpu_idle_prepare(void)
93 * This is our default idle handler.
95 void arch_cpu_idle(void)
98 * This should do all the clock switching and wait for interrupt
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");
144 void __show_regs(struct pt_regs *regs)
148 show_regs_print_info(KERN_DEFAULT);
149 print_symbol("PC is at %s\n", instruction_pointer(regs));
150 print_symbol("LR is at %s\n", regs->regs[30]);
151 printk("pc : [<%016llx>] lr : [<%016llx>] pstate: %08llx\n",
152 regs->pc, regs->regs[30], regs->pstate);
153 printk("sp : %016llx\n", regs->sp);
154 for (i = 29; i >= 0; i--) {
155 printk("x%-2d: %016llx ", i, regs->regs[i]);
162 void show_regs(struct pt_regs * regs)
169 * Free current thread data structures etc..
171 void exit_thread(void)
175 void flush_thread(void)
177 fpsimd_flush_thread();
178 flush_ptrace_hw_breakpoint(current);
181 void release_thread(struct task_struct *dead_task)
185 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
187 fpsimd_preserve_current_state();
192 asmlinkage void ret_from_fork(void) asm("ret_from_fork");
194 int copy_thread(unsigned long clone_flags, unsigned long stack_start,
195 unsigned long stk_sz, struct task_struct *p)
197 struct pt_regs *childregs = task_pt_regs(p);
198 unsigned long tls = p->thread.tp_value;
200 memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));
202 if (likely(!(p->flags & PF_KTHREAD))) {
203 *childregs = *current_pt_regs();
204 childregs->regs[0] = 0;
205 if (is_compat_thread(task_thread_info(p))) {
207 childregs->compat_sp = stack_start;
210 * Read the current TLS pointer from tpidr_el0 as it may be
211 * out-of-sync with the saved value.
213 asm("mrs %0, tpidr_el0" : "=r" (tls));
215 /* 16-byte aligned stack mandatory on AArch64 */
216 if (stack_start & 15)
218 childregs->sp = stack_start;
222 * If a TLS pointer was passed to clone (4th argument), use it
223 * for the new thread.
225 if (clone_flags & CLONE_SETTLS)
226 tls = childregs->regs[3];
228 memset(childregs, 0, sizeof(struct pt_regs));
229 childregs->pstate = PSR_MODE_EL1h;
230 p->thread.cpu_context.x19 = stack_start;
231 p->thread.cpu_context.x20 = stk_sz;
233 p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
234 p->thread.cpu_context.sp = (unsigned long)childregs;
235 p->thread.tp_value = tls;
237 ptrace_hw_copy_thread(p);
242 static void tls_thread_switch(struct task_struct *next)
244 unsigned long tpidr, tpidrro;
246 if (!is_compat_task()) {
247 asm("mrs %0, tpidr_el0" : "=r" (tpidr));
248 current->thread.tp_value = tpidr;
251 if (is_compat_thread(task_thread_info(next))) {
253 tpidrro = next->thread.tp_value;
255 tpidr = next->thread.tp_value;
260 " msr tpidr_el0, %0\n"
261 " msr tpidrro_el0, %1"
262 : : "r" (tpidr), "r" (tpidrro));
268 struct task_struct *__switch_to(struct task_struct *prev,
269 struct task_struct *next)
271 struct task_struct *last;
273 fpsimd_thread_switch(next);
274 tls_thread_switch(next);
275 hw_breakpoint_thread_switch(next);
276 contextidr_thread_switch(next);
279 * Complete any pending TLB or cache maintenance on this CPU in case
280 * the thread migrates to a different CPU.
284 /* the actual thread switch */
285 last = cpu_switch_to(prev, next);
290 unsigned long get_wchan(struct task_struct *p)
292 struct stackframe frame;
294 if (!p || p == current || p->state == TASK_RUNNING)
297 frame.fp = thread_saved_fp(p);
298 frame.sp = thread_saved_sp(p);
299 frame.pc = thread_saved_pc(p);
301 int ret = unwind_frame(&frame);
304 if (!in_sched_functions(frame.pc))
306 } while (count ++ < 16);
310 unsigned long arch_align_stack(unsigned long sp)
312 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
313 sp -= get_random_int() & ~PAGE_MASK;
317 static unsigned long randomize_base(unsigned long base)
319 unsigned long range_end = base + (STACK_RND_MASK << PAGE_SHIFT) + 1;
320 return randomize_range(base, range_end, 0) ? : base;
323 unsigned long arch_randomize_brk(struct mm_struct *mm)
325 return randomize_base(mm->brk);
328 unsigned long randomize_et_dyn(unsigned long base)
330 return randomize_base(base);