[linux-2.6-block.git] / arch / arm64 / kernel / process.c

/*
 * Based on arch/arm/kernel/process.c
 *
 * Original Copyright (C) 1995  Linus Torvalds
 * Copyright (C) 1996-2000 Russell King - Converted to ARM.
 * Copyright (C) 2012 ARM Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdarg.h>

#include <linux/export.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/user.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/interrupt.h>
#include <linux/kallsyms.h>
#include <linux/init.h>
#include <linux/cpu.h>
#include <linux/elfcore.h>
#include <linux/pm.h>
#include <linux/tick.h>
#include <linux/utsname.h>
#include <linux/uaccess.h>
#include <linux/random.h>
#include <linux/hw_breakpoint.h>
#include <linux/personality.h>
#include <linux/notifier.h>

#include <asm/compat.h>
#include <asm/cacheflush.h>
#include <asm/processor.h>
#include <asm/stacktrace.h>
#include <asm/fpsimd.h>

static void setup_restart(void)
{
	/*
	 * Tell the mm system that we are going to reboot -
	 * we may need it to insert some 1:1 mappings so that
	 * soft boot works.
	 */
	setup_mm_for_reboot();

	/* Clean and invalidate caches */
	flush_cache_all();

	/* Turn D-cache off */
	cpu_cache_off();

	/* Push out any further dirty data, and ensure cache is empty */
	flush_cache_all();
}

void soft_restart(unsigned long addr)
{
	setup_restart();
	cpu_reset(addr);
}

/*
 * Function pointers to optional machine specific functions
 */
void (*pm_power_off)(void);
EXPORT_SYMBOL_GPL(pm_power_off);

void (*pm_restart)(const char *cmd);
EXPORT_SYMBOL_GPL(pm_restart);


/*
 * This is our default idle handler.
 */
static void default_idle(void)
{
	/*
	 * This should do all the clock switching and wait for interrupt
	 * tricks
	 */
	cpu_do_idle();
	local_irq_enable();
}

void (*pm_idle)(void) = default_idle;
EXPORT_SYMBOL_GPL(pm_idle);

/*
 * The idle thread, has rather strange semantics for calling pm_idle,
 * but this is what x86 does and we need to do the same, so that
 * things like cpuidle get called in the same way.  The only difference
 * is that we always respect 'hlt_counter' to prevent low power idle.
 */
void cpu_idle(void)
{
	local_fiq_enable();

	/* endless idle loop with no priority at all */
	while (1) {
		tick_nohz_idle_enter();
		rcu_idle_enter();
		while (!need_resched()) {
			/*
			 * We need to disable interrupts here to ensure
			 * we don't miss a wakeup call.
			 */
			local_irq_disable();
			if (!need_resched()) {
				stop_critical_timings();
				pm_idle();
				start_critical_timings();
				/*
				 * pm_idle functions should always return
				 * with IRQs enabled.
				 */
				WARN_ON(irqs_disabled());
			} else {
				local_irq_enable();
			}
		}
		rcu_idle_exit();
		tick_nohz_idle_exit();
		schedule_preempt_disabled();
	}
}

void machine_shutdown(void)
{
#ifdef CONFIG_SMP
	smp_send_stop();
#endif
}

void machine_halt(void)
{
	machine_shutdown();
	while (1);
}

void machine_power_off(void)
{
	machine_shutdown();
	if (pm_power_off)
		pm_power_off();
}

void machine_restart(char *cmd)
{
	machine_shutdown();

	/* Disable interrupts first */
	local_irq_disable();
	local_fiq_disable();

	/* Now call the architecture specific reboot code. */
	if (pm_restart)
		pm_restart(cmd);

	/*
	 * Whoops - the architecture was unable to reboot.
	 */
	printk("Reboot failed -- System halted\n");
	while (1);
}

void __show_regs(struct pt_regs *regs)
{
	int i;

	printk("CPU: %d    %s  (%s %.*s)\n",
		raw_smp_processor_id(), print_tainted(),
		init_utsname()->release,
		(int)strcspn(init_utsname()->version, " "),
		init_utsname()->version);
	print_symbol("PC is at %s\n", instruction_pointer(regs));
	print_symbol("LR is at %s\n", regs->regs[30]);
	printk("pc : [<%016llx>] lr : [<%016llx>] pstate: %08llx\n",
	       regs->pc, regs->regs[30], regs->pstate);
	printk("sp : %016llx\n", regs->sp);
	for (i = 29; i >= 0; i--) {
		printk("x%-2d: %016llx ", i, regs->regs[i]);
		if (i % 2 == 0)
			printk("\n");
	}
	printk("\n");
}

void show_regs(struct pt_regs * regs)
{
	printk("\n");
	printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
	__show_regs(regs);
}

/*
 * Free current thread data structures etc..
 */
void exit_thread(void)
{
}

void flush_thread(void)
{
	fpsimd_flush_thread();
	flush_ptrace_hw_breakpoint(current);
}

void release_thread(struct task_struct *dead_task)
{
}

int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
{
	fpsimd_save_state(&current->thread.fpsimd_state);
	*dst = *src;
	return 0;
}

asmlinkage void ret_from_fork(void) asm("ret_from_fork");

int copy_thread(unsigned long clone_flags, unsigned long stack_start,
		unsigned long stk_sz, struct task_struct *p,
		struct pt_regs *regs)
{
	struct pt_regs *childregs = task_pt_regs(p);
	unsigned long tls = p->thread.tp_value;

	*childregs = *regs;
	childregs->regs[0] = 0;

	if (is_compat_thread(task_thread_info(p)))
		childregs->compat_sp = stack_start;
	else {
		/*
		 * Read the current TLS pointer from tpidr_el0 as it may be
		 * out-of-sync with the saved value.
		 */
		asm("mrs %0, tpidr_el0" : "=r" (tls));
		childregs->sp = stack_start;
	}

	memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));
	p->thread.cpu_context.sp = (unsigned long)childregs;
	p->thread.cpu_context.pc = (unsigned long)ret_from_fork;

	/* If a TLS pointer was passed to clone, use that for the new thread. */
	if (clone_flags & CLONE_SETTLS)
		tls = regs->regs[3];
	p->thread.tp_value = tls;

	ptrace_hw_copy_thread(p);

	return 0;
}

static void tls_thread_switch(struct task_struct *next)
{
	unsigned long tpidr, tpidrro;

	if (!is_compat_task()) {
		asm("mrs %0, tpidr_el0" : "=r" (tpidr));
		current->thread.tp_value = tpidr;
	}

	if (is_compat_thread(task_thread_info(next))) {
		tpidr = 0;
		tpidrro = next->thread.tp_value;
	} else {
		tpidr = next->thread.tp_value;
		tpidrro = 0;
	}

	asm(
	"	msr	tpidr_el0, %0\n"
	"	msr	tpidrro_el0, %1"
	: : "r" (tpidr), "r" (tpidrro));
}

/*
 * Thread switching.
 */
struct task_struct *__switch_to(struct task_struct *prev,
				struct task_struct *next)
{
	struct task_struct *last;

	fpsimd_thread_switch(next);
	tls_thread_switch(next);
	hw_breakpoint_thread_switch(next);

	/* the actual thread switch */
	last = cpu_switch_to(prev, next);

	return last;
}

/*
 * Fill in the task's elfregs structure for a core dump.
 */
int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
{
	elf_core_copy_regs(elfregs, task_pt_regs(t));
	return 1;
}

/*
 * fill in the fpe structure for a core dump...
 */
int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
{
	return 0;
}
EXPORT_SYMBOL(dump_fpu);

/*
 * Shuffle the argument into the correct register before calling the
 * thread function.  x1 is the thread argument, x2 is the pointer to
 * the thread function, and x3 points to the exit function.
 */
extern void kernel_thread_helper(void);
asm(	".section .text\n"
"	.align\n"
"	.type	kernel_thread_helper, #function\n"
"kernel_thread_helper:\n"
"	mov	x0, x1\n"
"	mov	x30, x3\n"
"	br	x2\n"
"	.size	kernel_thread_helper, . - kernel_thread_helper\n"
"	.previous");

#define kernel_thread_exit	do_exit

/*
 * Create a kernel thread.
 */
pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{
	struct pt_regs regs;

	memset(&regs, 0, sizeof(regs));

	regs.regs[1] = (unsigned long)arg;
	regs.regs[2] = (unsigned long)fn;
	regs.regs[3] = (unsigned long)kernel_thread_exit;
	regs.pc = (unsigned long)kernel_thread_helper;
	regs.pstate = PSR_MODE_EL1h;

	return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
}
EXPORT_SYMBOL(kernel_thread);

unsigned long get_wchan(struct task_struct *p)
{
	struct stackframe frame;
	int count = 0;
	if (!p || p == current || p->state == TASK_RUNNING)
		return 0;

	frame.fp = thread_saved_fp(p);
	frame.sp = thread_saved_sp(p);
	frame.pc = thread_saved_pc(p);
	do {
		int ret = unwind_frame(&frame);
		if (ret < 0)
			return 0;
		if (!in_sched_functions(frame.pc))
			return frame.pc;
	} while (count ++ < 16);
	return 0;
}

unsigned long arch_align_stack(unsigned long sp)
{
	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
		sp -= get_random_int() & ~PAGE_MASK;
	return sp & ~0xf;
}

static unsigned long randomize_base(unsigned long base)
{
	unsigned long range_end = base + (STACK_RND_MASK << PAGE_SHIFT) + 1;
	return randomize_range(base, range_end, 0) ? : base;
}

unsigned long arch_randomize_brk(struct mm_struct *mm)
{
	return randomize_base(mm->brk);
}

unsigned long randomize_et_dyn(unsigned long base)
{
	return randomize_base(base);
}
Commit	Line	Data
b3901d54 CM	1	/*
	2	* Based on arch/arm/kernel/process.c
	3	*
	4	* Original Copyright (C) 1995 Linus Torvalds
	5	* Copyright (C) 1996-2000 Russell King - Converted to ARM.
	6	* Copyright (C) 2012 ARM Ltd.
	7	*
	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.
	11	*
	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.
	16	*
	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/>.
	19	*/
	20
	21	#include <stdarg.h>
	22
	23	#include <linux/export.h>
	24	#include <linux/sched.h>
	25	#include <linux/kernel.h>
	26	#include <linux/mm.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>
	37	#include <linux/pm.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>
	45
	46	#include <asm/compat.h>
	47	#include <asm/cacheflush.h>
	48	#include <asm/processor.h>
	49	#include <asm/stacktrace.h>
	50	#include <asm/fpsimd.h>
	51
	52	static void setup_restart(void)
	53	{
	54	/*
	55	* Tell the mm system that we are going to reboot -
	56	* we may need it to insert some 1:1 mappings so that
	57	* soft boot works.
	58	*/
	59	setup_mm_for_reboot();
	60
	61	/* Clean and invalidate caches */
	62	flush_cache_all();
	63
	64	/* Turn D-cache off */
65	cpu_cache_off();
66
67	/* Push out any further dirty data, and ensure cache is empty */
68	flush_cache_all();
69	}
70
71	void soft_restart(unsigned long addr)
72	{
73	setup_restart();
74	cpu_reset(addr);
75	}
76
77	/*
78	* Function pointers to optional machine specific functions
79	*/
80	void (*pm_power_off)(void);
81	EXPORT_SYMBOL_GPL(pm_power_off);
82
83	void (pm_restart)(const char cmd);
84	EXPORT_SYMBOL_GPL(pm_restart);
85
86
87	/*
88	* This is our default idle handler.
89	*/
90	static void default_idle(void)
91	{
92	/*
93	* This should do all the clock switching and wait for interrupt
94	* tricks
95	*/
96	cpu_do_idle();
97	local_irq_enable();
98	}
99
100	void (*pm_idle)(void) = default_idle;
101	EXPORT_SYMBOL_GPL(pm_idle);
102
103	/*
104	* The idle thread, has rather strange semantics for calling pm_idle,
105	* but this is what x86 does and we need to do the same, so that
106	* things like cpuidle get called in the same way. The only difference
107	* is that we always respect 'hlt_counter' to prevent low power idle.
108	*/
109	void cpu_idle(void)
110	{
111	local_fiq_enable();
112
113	/* endless idle loop with no priority at all */
114	while (1) {
115	tick_nohz_idle_enter();
116	rcu_idle_enter();
117	while (!need_resched()) {
118	/*
119	* We need to disable interrupts here to ensure
120	* we don't miss a wakeup call.
121	*/
122	local_irq_disable();
123	if (!need_resched()) {
124	stop_critical_timings();
125	pm_idle();
126	start_critical_timings();
127	/*
128	* pm_idle functions should always return
129	* with IRQs enabled.
130	*/
131	WARN_ON(irqs_disabled());
132	} else {
133	local_irq_enable();
134	}
135	}
136	rcu_idle_exit();
137	tick_nohz_idle_exit();
138	schedule_preempt_disabled();
139	}
140	}
141
142	void machine_shutdown(void)
143	{
144	#ifdef CONFIG_SMP
145	smp_send_stop();
146	#endif
147	}
148
149	void machine_halt(void)
150	{
151	machine_shutdown();
152	while (1);
153	}
154
155	void machine_power_off(void)
156	{
157	machine_shutdown();
158	if (pm_power_off)
159	pm_power_off();
160	}
161
162	void machine_restart(char *cmd)
163	{
164	machine_shutdown();
165
166	/* Disable interrupts first */
167	local_irq_disable();
168	local_fiq_disable();
169
170	/* Now call the architecture specific reboot code. */
171	if (pm_restart)
172	pm_restart(cmd);
173
174	/*
175	* Whoops - the architecture was unable to reboot.
176	*/
177	printk("Reboot failed -- System halted\n");
178	while (1);
179	}
180
181	void __show_regs(struct pt_regs *regs)
182	{
183	int i;
184
185	printk("CPU: %d %s (%s %.*s)\n",
186	raw_smp_processor_id(), print_tainted(),
187	init_utsname()->release,
188	(int)strcspn(init_utsname()->version, " "),
189	init_utsname()->version);
190	print_symbol("PC is at %s\n", instruction_pointer(regs));
191	print_symbol("LR is at %s\n", regs->regs[30]);
192	printk("pc : [<%016llx>] lr : [<%016llx>] pstate: %08llx\n",
193	regs->pc, regs->regs[30], regs->pstate);
194	printk("sp : %016llx\n", regs->sp);
195	for (i = 29; i >= 0; i--) {
196	printk("x%-2d: %016llx ", i, regs->regs[i]);
197	if (i % 2 == 0)
198	printk("\n");
199	}
200	printk("\n");
201	}
202
203	void show_regs(struct pt_regs * regs)
204	{
205	printk("\n");
206	printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
207	__show_regs(regs);
208	}
209
210	/*
211	* Free current thread data structures etc..
212	*/
213	void exit_thread(void)
214	{
215	}
216
217	void flush_thread(void)
218	{
219	fpsimd_flush_thread();
220	flush_ptrace_hw_breakpoint(current);
221	}
222
223	void release_thread(struct task_struct *dead_task)
224	{
225	}
226
227	int arch_dup_task_struct(struct task_struct dst, struct task_struct src)
228	{
229	fpsimd_save_state(&current->thread.fpsimd_state);
230	dst = src;
231	return 0;
232	}
233
234	asmlinkage void ret_from_fork(void) asm("ret_from_fork");
235
236	int copy_thread(unsigned long clone_flags, unsigned long stack_start,
237	unsigned long stk_sz, struct task_struct *p,
238	struct pt_regs *regs)
239	{
240	struct pt_regs *childregs = task_pt_regs(p);
241	unsigned long tls = p->thread.tp_value;
242
243	childregs = regs;
244	childregs->regs[0] = 0;
245
246	if (is_compat_thread(task_thread_info(p)))
247	childregs->compat_sp = stack_start;
248	else {
249	/*
250	* Read the current TLS pointer from tpidr_el0 as it may be
251	* out-of-sync with the saved value.
252	*/
253	asm("mrs %0, tpidr_el0" : "=r" (tls));
254	childregs->sp = stack_start;
255	}
256
257	memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));
258	p->thread.cpu_context.sp = (unsigned long)childregs;
259	p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
260
261	/* If a TLS pointer was passed to clone, use that for the new thread. */
262	if (clone_flags & CLONE_SETTLS)
263	tls = regs->regs[3];
264	p->thread.tp_value = tls;
265
266	ptrace_hw_copy_thread(p);
267
268	return 0;
269	}
270
271	static void tls_thread_switch(struct task_struct *next)
272	{
273	unsigned long tpidr, tpidrro;
274
275	if (!is_compat_task()) {
276	asm("mrs %0, tpidr_el0" : "=r" (tpidr));
277	current->thread.tp_value = tpidr;
278	}
279
280	if (is_compat_thread(task_thread_info(next))) {
281	tpidr = 0;
282	tpidrro = next->thread.tp_value;
283	} else {
284	tpidr = next->thread.tp_value;
285	tpidrro = 0;
286	}
287
288	asm(
289	" msr tpidr_el0, %0\n"
290	" msr tpidrro_el0, %1"
291	: : "r" (tpidr), "r" (tpidrro));
292	}
293
294	/*
295	* Thread switching.
296	*/
297	struct task_struct __switch_to(struct task_struct prev,
298	struct task_struct *next)
299	{
300	struct task_struct *last;
301
302	fpsimd_thread_switch(next);
303	tls_thread_switch(next);
304	hw_breakpoint_thread_switch(next);
305
306	/* the actual thread switch */
307	last = cpu_switch_to(prev, next);
308
309	return last;
310	}
311
312	/*
313	* Fill in the task's elfregs structure for a core dump.
314	*/
315	int dump_task_regs(struct task_struct t, elf_gregset_t elfregs)
316	{
317	elf_core_copy_regs(elfregs, task_pt_regs(t));
318	return 1;
319	}
320
321	/*
322	* fill in the fpe structure for a core dump...
323	*/
324	int dump_fpu (struct pt_regs regs, struct user_fp fp)
325	{
326	return 0;
327	}
328	EXPORT_SYMBOL(dump_fpu);
329
330	/*
331	* Shuffle the argument into the correct register before calling the
332	* thread function. x1 is the thread argument, x2 is the pointer to
333	* the thread function, and x3 points to the exit function.
334	*/
335	extern void kernel_thread_helper(void);
336	asm( ".section .text\n"
337	" .align\n"
338	" .type kernel_thread_helper, #function\n"
339	"kernel_thread_helper:\n"
340	" mov x0, x1\n"
341	" mov x30, x3\n"
342	" br x2\n"
343	" .size kernel_thread_helper, . - kernel_thread_helper\n"
344	" .previous");
345
346	#define kernel_thread_exit do_exit
347
348	/*
349	* Create a kernel thread.
350	*/
351	pid_t kernel_thread(int (fn)(void ), void *arg, unsigned long flags)
352	{
353	struct pt_regs regs;
354
355	memset(&regs, 0, sizeof(regs));
356
357	regs.regs[1] = (unsigned long)arg;
358	regs.regs[2] = (unsigned long)fn;
359	regs.regs[3] = (unsigned long)kernel_thread_exit;
360	regs.pc = (unsigned long)kernel_thread_helper;
361	regs.pstate = PSR_MODE_EL1h;
362
363	return do_fork(flags\|CLONE_VM\|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
364	}
365	EXPORT_SYMBOL(kernel_thread);
366
367	unsigned long get_wchan(struct task_struct *p)
368	{
369	struct stackframe frame;
370	int count = 0;
371	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
372	return 0;
373
374	frame.fp = thread_saved_fp(p);
375	frame.sp = thread_saved_sp(p);
376	frame.pc = thread_saved_pc(p);
377	do {
378	int ret = unwind_frame(&frame);
379	if (ret < 0)
380	return 0;
381	if (!in_sched_functions(frame.pc))
382	return frame.pc;
383	} while (count ++ < 16);
384	return 0;
385	}
386
387	unsigned long arch_align_stack(unsigned long sp)
388	{
389	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
390	sp -= get_random_int() & ~PAGE_MASK;
391	return sp & ~0xf;
392	}
393
394	static unsigned long randomize_base(unsigned long base)
395	{
396	unsigned long range_end = base + (STACK_RND_MASK << PAGE_SHIFT) + 1;
397	return randomize_range(base, range_end, 0) ? : base;
398	}
399
400	unsigned long arch_randomize_brk(struct mm_struct *mm)
401	{
402	return randomize_base(mm->brk);
403	}
404
405	unsigned long randomize_et_dyn(unsigned long base)
406	{
407	return randomize_base(base);
408	}