[deliverable/linux.git] / arch / xtensa / kernel / process.c

/*
 * arch/xtensa/kernel/process.c
 *
 * Xtensa Processor version.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2001 - 2005 Tensilica Inc.
 *
 * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
 * Chris Zankel <chris@zankel.net>
 * Marc Gauthier <marc@tensilica.com, marc@alumni.uwaterloo.ca>
 * Kevin Chea
 */

#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/elf.h>
#include <linux/init.h>
#include <linux/prctl.h>
#include <linux/init_task.h>
#include <linux/module.h>
#include <linux/mqueue.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/rcupdate.h>

#include <asm/pgtable.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/platform.h>
#include <asm/mmu.h>
#include <asm/irq.h>
#include <linux/atomic.h>
#include <asm/asm-offsets.h>
#include <asm/regs.h>

extern void ret_from_fork(void);
extern void ret_from_kernel_thread(void);

struct task_struct *current_set[NR_CPUS] = {&init_task, };

void (*pm_power_off)(void) = NULL;
EXPORT_SYMBOL(pm_power_off);


#if XTENSA_HAVE_COPROCESSORS

void coprocessor_release_all(struct thread_info *ti)
{
	unsigned long cpenable;
	int i;

	/* Make sure we don't switch tasks during this operation. */

	preempt_disable();

	/* Walk through all cp owners and release it for the requested one. */

	cpenable = ti->cpenable;

	for (i = 0; i < XCHAL_CP_MAX; i++) {
		if (coprocessor_owner[i] == ti) {
			coprocessor_owner[i] = 0;
			cpenable &= ~(1 << i);
		}
	}

	ti->cpenable = cpenable;
	coprocessor_clear_cpenable();

	preempt_enable();
}

void coprocessor_flush_all(struct thread_info *ti)
{
	unsigned long cpenable;
	int i;

	preempt_disable();

	cpenable = ti->cpenable;

	for (i = 0; i < XCHAL_CP_MAX; i++) {
		if ((cpenable & 1) != 0 && coprocessor_owner[i] == ti)
			coprocessor_flush(ti, i);
		cpenable >>= 1;
	}

	preempt_enable();
}

#endif


/*
 * Powermanagement idle function, if any is provided by the platform.
 */
void arch_cpu_idle(void)
{
	platform_idle();
}

/*
 * This is called when the thread calls exit().
 */
void exit_thread(void)
{
#if XTENSA_HAVE_COPROCESSORS
	coprocessor_release_all(current_thread_info());
#endif
}

/*
 * Flush thread state. This is called when a thread does an execve()
 * Note that we flush coprocessor registers for the case execve fails.
 */
void flush_thread(void)
{
#if XTENSA_HAVE_COPROCESSORS
	struct thread_info *ti = current_thread_info();
	coprocessor_flush_all(ti);
	coprocessor_release_all(ti);
#endif
}

/*
 * this gets called so that we can store coprocessor state into memory and
 * copy the current task into the new thread.
 */
int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
{
#if XTENSA_HAVE_COPROCESSORS
	coprocessor_flush_all(task_thread_info(src));
#endif
	*dst = *src;
	return 0;
}

/*
 * Copy thread.
 *
 * There are two modes in which this function is called:
 * 1) Userspace thread creation,
 *    regs != NULL, usp_thread_fn is userspace stack pointer.
 *    It is expected to copy parent regs (in case CLONE_VM is not set
 *    in the clone_flags) and set up passed usp in the childregs.
 * 2) Kernel thread creation,
 *    regs == NULL, usp_thread_fn is the function to run in the new thread
 *    and thread_fn_arg is its parameter.
 *    childregs are not used for the kernel threads.
 *
 * The stack layout for the new thread looks like this:
 *
 *	+------------------------+
 *	|       childregs        |
 *	+------------------------+ <- thread.sp = sp in dummy-frame
 *	|      dummy-frame       |    (saved in dummy-frame spill-area)
 *	+------------------------+
 *
 * We create a dummy frame to return to either ret_from_fork or
 *   ret_from_kernel_thread:
 *   a0 points to ret_from_fork/ret_from_kernel_thread (simulating a call4)
 *   sp points to itself (thread.sp)
 *   a2, a3 are unused for userspace threads,
 *   a2 points to thread_fn, a3 holds thread_fn arg for kernel threads.
 *
 * Note: This is a pristine frame, so we don't need any spill region on top of
 *       childregs.
 *
 * The fun part:  if we're keeping the same VM (i.e. cloning a thread,
 * not an entire process), we're normally given a new usp, and we CANNOT share
 * any live address register windows.  If we just copy those live frames over,
 * the two threads (parent and child) will overflow the same frames onto the
 * parent stack at different times, likely corrupting the parent stack (esp.
 * if the parent returns from functions that called clone() and calls new
 * ones, before the child overflows its now old copies of its parent windows).
 * One solution is to spill windows to the parent stack, but that's fairly
 * involved.  Much simpler to just not copy those live frames across.
 */

int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn,
		unsigned long thread_fn_arg, struct task_struct *p)
{
	struct pt_regs *childregs = task_pt_regs(p);

#if (XTENSA_HAVE_COPROCESSORS || XTENSA_HAVE_IO_PORTS)
	struct thread_info *ti;
#endif

	/* Create a call4 dummy-frame: a0 = 0, a1 = childregs. */
	*((int*)childregs - 3) = (unsigned long)childregs;
	*((int*)childregs - 4) = 0;

	p->thread.sp = (unsigned long)childregs;

	if (!(p->flags & PF_KTHREAD)) {
		struct pt_regs *regs = current_pt_regs();
		unsigned long usp = usp_thread_fn ?
			usp_thread_fn : regs->areg[1];

		p->thread.ra = MAKE_RA_FOR_CALL(
				(unsigned long)ret_from_fork, 0x1);

		/* This does not copy all the regs.
		 * In a bout of brilliance or madness,
		 * ARs beyond a0-a15 exist past the end of the struct.
		 */
		*childregs = *regs;
		childregs->areg[1] = usp;
		childregs->areg[2] = 0;

		/* When sharing memory with the parent thread, the child
		   usually starts on a pristine stack, so we have to reset
		   windowbase, windowstart and wmask.
		   (Note that such a new thread is required to always create
		   an initial call4 frame)
		   The exception is vfork, where the new thread continues to
		   run on the parent's stack until it calls execve. This could
		   be a call8 or call12, which requires a legal stack frame
		   of the previous caller for the overflow handlers to work.
		   (Note that it's always legal to overflow live registers).
		   In this case, ensure to spill at least the stack pointer
		   of that frame. */

		if (clone_flags & CLONE_VM) {
			/* check that caller window is live and same stack */
			int len = childregs->wmask & ~0xf;
			if (regs->areg[1] == usp && len != 0) {
				int callinc = (regs->areg[0] >> 30) & 3;
				int caller_ars = XCHAL_NUM_AREGS - callinc * 4;
				put_user(regs->areg[caller_ars+1],
					 (unsigned __user*)(usp - 12));
			}
			childregs->wmask = 1;
			childregs->windowstart = 1;
			childregs->windowbase = 0;
		} else {
			int len = childregs->wmask & ~0xf;
			memcpy(&childregs->areg[XCHAL_NUM_AREGS - len/4],
			       &regs->areg[XCHAL_NUM_AREGS - len/4], len);
		}

		/* The thread pointer is passed in the '4th argument' (= a5) */
		if (clone_flags & CLONE_SETTLS)
			childregs->threadptr = childregs->areg[5];
	} else {
		p->thread.ra = MAKE_RA_FOR_CALL(
				(unsigned long)ret_from_kernel_thread, 1);

		/* pass parameters to ret_from_kernel_thread:
		 * a2 = thread_fn, a3 = thread_fn arg
		 */
		*((int *)childregs - 1) = thread_fn_arg;
		*((int *)childregs - 2) = usp_thread_fn;

		/* Childregs are only used when we're going to userspace
		 * in which case start_thread will set them up.
		 */
	}

#if (XTENSA_HAVE_COPROCESSORS || XTENSA_HAVE_IO_PORTS)
	ti = task_thread_info(p);
	ti->cpenable = 0;
#endif

	return 0;
}


/*
 * These bracket the sleeping functions..
 */

unsigned long get_wchan(struct task_struct *p)
{
	unsigned long sp, pc;
	unsigned long stack_page = (unsigned long) task_stack_page(p);
	int count = 0;

	if (!p || p == current || p->state == TASK_RUNNING)
		return 0;

	sp = p->thread.sp;
	pc = MAKE_PC_FROM_RA(p->thread.ra, p->thread.sp);

	do {
		if (sp < stack_page + sizeof(struct task_struct) ||
		    sp >= (stack_page + THREAD_SIZE) ||
		    pc == 0)
			return 0;
		if (!in_sched_functions(pc))
			return pc;

		/* Stack layout: sp-4: ra, sp-3: sp' */

		pc = MAKE_PC_FROM_RA(*(unsigned long*)sp - 4, sp);
		sp = *(unsigned long *)sp - 3;
	} while (count++ < 16);
	return 0;
}

/*
 * xtensa_gregset_t and 'struct pt_regs' are vastly different formats
 * of processor registers.  Besides different ordering,
 * xtensa_gregset_t contains non-live register information that
 * 'struct pt_regs' does not.  Exception handling (primarily) uses
 * 'struct pt_regs'.  Core files and ptrace use xtensa_gregset_t.
 *
 */

void xtensa_elf_core_copy_regs (xtensa_gregset_t *elfregs, struct pt_regs *regs)
{
	unsigned long wb, ws, wm;
	int live, last;

	wb = regs->windowbase;
	ws = regs->windowstart;
	wm = regs->wmask;
	ws = ((ws >> wb) | (ws << (WSBITS - wb))) & ((1 << WSBITS) - 1);

	/* Don't leak any random bits. */

	memset(elfregs, 0, sizeof(*elfregs));

	/* Note:  PS.EXCM is not set while user task is running; its
	 * being set in regs->ps is for exception handling convenience.
	 */

	elfregs->pc		= regs->pc;
	elfregs->ps		= (regs->ps & ~(1 << PS_EXCM_BIT));
	elfregs->lbeg		= regs->lbeg;
	elfregs->lend		= regs->lend;
	elfregs->lcount		= regs->lcount;
	elfregs->sar		= regs->sar;
	elfregs->windowstart	= ws;

	live = (wm & 2) ? 4 : (wm & 4) ? 8 : (wm & 8) ? 12 : 16;
	last = XCHAL_NUM_AREGS - (wm >> 4) * 4;
	memcpy(elfregs->a, regs->areg, live * 4);
	memcpy(elfregs->a + last, regs->areg + last, (wm >> 4) * 16);
}

int dump_fpu(void)
{
	return 0;
}
Commit	Line	Data
5a0015d6 CZ	1	/*
	2	* arch/xtensa/kernel/process.c
	3	*
	4	* Xtensa Processor version.
	5	*
	6	* This file is subject to the terms and conditions of the GNU General Public
	7	* License. See the file "COPYING" in the main directory of this archive
	8	* for more details.
	9	*
	10	* Copyright (C) 2001 - 2005 Tensilica Inc.
	11	*
	12	* Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
	13	* Chris Zankel <chris@zankel.net>
	14	* Marc Gauthier <marc@tensilica.com, marc@alumni.uwaterloo.ca>
	15	* Kevin Chea
	16	*/
	17
5a0015d6 CZ	18	#include <linux/errno.h>
	19	#include <linux/sched.h>
	20	#include <linux/kernel.h>
	21	#include <linux/mm.h>
	22	#include <linux/smp.h>
5a0015d6 CZ	23	#include <linux/stddef.h>
	24	#include <linux/unistd.h>
	25	#include <linux/ptrace.h>
5a0015d6 CZ	26	#include <linux/elf.h>
	27	#include <linux/init.h>
	28	#include <linux/prctl.h>
	29	#include <linux/init_task.h>
	30	#include <linux/module.h>
	31	#include <linux/mqueue.h>
73089cbf	32	#include <linux/fs.h>
5a0e3ad6	33	#include <linux/slab.h>
11ad47a0	34	#include <linux/rcupdate.h>
5a0015d6 CZ	35
	36	#include <asm/pgtable.h>
	37	#include <asm/uaccess.h>
5a0015d6 CZ	38	#include <asm/io.h>
	39	#include <asm/processor.h>
	40	#include <asm/platform.h>
	41	#include <asm/mmu.h>
	42	#include <asm/irq.h>
60063497	43	#include <linux/atomic.h>
0013a854	44	#include <asm/asm-offsets.h>
173d6681	45	#include <asm/regs.h>
5a0015d6 CZ	46
5a0015d6 CZ	47	extern void ret_from_fork(void);
3306a726	48	extern void ret_from_kernel_thread(void);
5a0015d6	49
5a0015d6 CZ	50	struct task_struct *current_set[NR_CPUS] = {&init_task, };
5a0015d6 CZ	51
47f3fc94 AB	52	void (*pm_power_off)(void) = NULL;
	53	EXPORT_SYMBOL(pm_power_off);
	54
5a0015d6	55
c658eac6 CZ	56	#if XTENSA_HAVE_COPROCESSORS
	57
	58	void coprocessor_release_all(struct thread_info *ti)
	59	{
	60	unsigned long cpenable;
	61	int i;
	62
	63	/* Make sure we don't switch tasks during this operation. */
	64
	65	preempt_disable();
	66
	67	/* Walk through all cp owners and release it for the requested one. */
	68
	69	cpenable = ti->cpenable;
	70
	71	for (i = 0; i < XCHAL_CP_MAX; i++) {
	72	if (coprocessor_owner[i] == ti) {
	73	coprocessor_owner[i] = 0;
	74	cpenable &= ~(1 << i);
	75	}
	76	}
	77
	78	ti->cpenable = cpenable;
	79	coprocessor_clear_cpenable();
	80
	81	preempt_enable();
	82	}
	83
	84	void coprocessor_flush_all(struct thread_info *ti)
	85	{
	86	unsigned long cpenable;
	87	int i;
	88
	89	preempt_disable();
	90
	91	cpenable = ti->cpenable;
	92
	93	for (i = 0; i < XCHAL_CP_MAX; i++) {
	94	if ((cpenable & 1) != 0 && coprocessor_owner[i] == ti)
	95	coprocessor_flush(ti, i);
	96	cpenable >>= 1;
	97	}
	98
	99	preempt_enable();
	100	}
	101
	102	#endif
	103
	104
5a0015d6 CZ	105	/*
	106	* Powermanagement idle function, if any is provided by the platform.
	107	*/
f4e2e9a4	108	void arch_cpu_idle(void)
5a0015d6	109	{
f4e2e9a4	110	platform_idle();
5a0015d6 CZ	111	}
	112
	113	/*
c658eac6	114	* This is called when the thread calls exit().
5a0015d6	115	*/
5a0015d6 CZ	116	void exit_thread(void)
5a0015d6 CZ	117	{
c658eac6 CZ	118	#if XTENSA_HAVE_COPROCESSORS
	119	coprocessor_release_all(current_thread_info());
	120	#endif
5a0015d6 CZ	121	}
5a0015d6 CZ	122
c658eac6 CZ	123	/*
	124	* Flush thread state. This is called when a thread does an execve()
	125	* Note that we flush coprocessor registers for the case execve fails.
	126	*/
5a0015d6 CZ	127	void flush_thread(void)
5a0015d6 CZ	128	{
c658eac6 CZ	129	#if XTENSA_HAVE_COPROCESSORS
	130	struct thread_info *ti = current_thread_info();
	131	coprocessor_flush_all(ti);
	132	coprocessor_release_all(ti);
	133	#endif
	134	}
	135
	136	/*
55ccf3fe SS	137	* this gets called so that we can store coprocessor state into memory and
55ccf3fe SS	138	* copy the current task into the new thread.
c658eac6	139	*/
55ccf3fe	140	int arch_dup_task_struct(struct task_struct dst, struct task_struct src)
c658eac6 CZ	141	{
c658eac6 CZ	142	#if XTENSA_HAVE_COPROCESSORS
55ccf3fe	143	coprocessor_flush_all(task_thread_info(src));
c658eac6	144	#endif
55ccf3fe SS	145	dst = src;
55ccf3fe SS	146	return 0;
5a0015d6 CZ	147	}
	148
	149	/*
	150	* Copy thread.
	151	*
3306a726 MF	152	* There are two modes in which this function is called:
	153	* 1) Userspace thread creation,
	154	* regs != NULL, usp_thread_fn is userspace stack pointer.
	155	* It is expected to copy parent regs (in case CLONE_VM is not set
	156	* in the clone_flags) and set up passed usp in the childregs.
	157	* 2) Kernel thread creation,
	158	* regs == NULL, usp_thread_fn is the function to run in the new thread
	159	* and thread_fn_arg is its parameter.
	160	* childregs are not used for the kernel threads.
	161	*
5a0015d6 CZ	162	* The stack layout for the new thread looks like this:
5a0015d6 CZ	163	*
3306a726	164	* +------------------------+
5a0015d6 CZ	165	* \| childregs \|
	166	* +------------------------+ <- thread.sp = sp in dummy-frame
	167	* \| dummy-frame \| (saved in dummy-frame spill-area)
	168	* +------------------------+
	169	*
3306a726 MF	170	* We create a dummy frame to return to either ret_from_fork or
	171	* ret_from_kernel_thread:
	172	* a0 points to ret_from_fork/ret_from_kernel_thread (simulating a call4)
5a0015d6	173	* sp points to itself (thread.sp)
3306a726 MF	174	* a2, a3 are unused for userspace threads,
3306a726 MF	175	* a2 points to thread_fn, a3 holds thread_fn arg for kernel threads.
5a0015d6 CZ	176	*
	177	* Note: This is a pristine frame, so we don't need any spill region on top of
	178	* childregs.
84ed3053 MG	179	*
	180	* The fun part: if we're keeping the same VM (i.e. cloning a thread,
	181	* not an entire process), we're normally given a new usp, and we CANNOT share
	182	* any live address register windows. If we just copy those live frames over,
	183	* the two threads (parent and child) will overflow the same frames onto the
	184	* parent stack at different times, likely corrupting the parent stack (esp.
	185	* if the parent returns from functions that called clone() and calls new
	186	* ones, before the child overflows its now old copies of its parent windows).
	187	* One solution is to spill windows to the parent stack, but that's fairly
	188	* involved. Much simpler to just not copy those live frames across.
5a0015d6 CZ	189	*/
5a0015d6 CZ	190
3306a726	191	int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn,
afa86fc4	192	unsigned long thread_fn_arg, struct task_struct *p)
5a0015d6	193	{
3306a726	194	struct pt_regs *childregs = task_pt_regs(p);
5a0015d6	195
39070cb8 CZ	196	#if (XTENSA_HAVE_COPROCESSORS \|\| XTENSA_HAVE_IO_PORTS)
	197	struct thread_info *ti;
	198	#endif
	199
5a0015d6 CZ	200	/* Create a call4 dummy-frame: a0 = 0, a1 = childregs. */
	201	((int)childregs - 3) = (unsigned long)childregs;
	202	((int)childregs - 4) = 0;
	203
5a0015d6	204	p->thread.sp = (unsigned long)childregs;
c658eac6	205
3306a726 MF	206	if (!(p->flags & PF_KTHREAD)) {
	207	struct pt_regs *regs = current_pt_regs();
	208	unsigned long usp = usp_thread_fn ?
	209	usp_thread_fn : regs->areg[1];
	210
	211	p->thread.ra = MAKE_RA_FOR_CALL(
	212	(unsigned long)ret_from_fork, 0x1);
5a0015d6	213
3306a726 MF	214	/* This does not copy all the regs.
	215	* In a bout of brilliance or madness,
	216	* ARs beyond a0-a15 exist past the end of the struct.
	217	*/
	218	childregs = regs;
5a0015d6	219	childregs->areg[1] = usp;
3306a726	220	childregs->areg[2] = 0;
6ebe7da2 CZ	221
	222	/* When sharing memory with the parent thread, the child
	223	usually starts on a pristine stack, so we have to reset
	224	windowbase, windowstart and wmask.
	225	(Note that such a new thread is required to always create
	226	an initial call4 frame)
	227	The exception is vfork, where the new thread continues to
	228	run on the parent's stack until it calls execve. This could
	229	be a call8 or call12, which requires a legal stack frame
	230	of the previous caller for the overflow handlers to work.
	231	(Note that it's always legal to overflow live registers).
	232	In this case, ensure to spill at least the stack pointer
	233	of that frame. */
	234
84ed3053	235	if (clone_flags & CLONE_VM) {
6ebe7da2 CZ	236	/* check that caller window is live and same stack */
	237	int len = childregs->wmask & ~0xf;
	238	if (regs->areg[1] == usp && len != 0) {
	239	int callinc = (regs->areg[0] >> 30) & 3;
	240	int caller_ars = XCHAL_NUM_AREGS - callinc * 4;
	241	put_user(regs->areg[caller_ars+1],
	242	(unsigned __user*)(usp - 12));
	243	}
	244	childregs->wmask = 1;
	245	childregs->windowstart = 1;
	246	childregs->windowbase = 0;
84ed3053 MG	247	} else {
	248	int len = childregs->wmask & ~0xf;
	249	memcpy(&childregs->areg[XCHAL_NUM_AREGS - len/4],
	250	&regs->areg[XCHAL_NUM_AREGS - len/4], len);
	251	}
c50842df CZ	252
c50842df CZ	253	/* The thread pointer is passed in the '4th argument' (= a5) */
5a0015d6	254	if (clone_flags & CLONE_SETTLS)
c50842df	255	childregs->threadptr = childregs->areg[5];
5a0015d6	256	} else {
3306a726 MF	257	p->thread.ra = MAKE_RA_FOR_CALL(
	258	(unsigned long)ret_from_kernel_thread, 1);
	259
	260	/* pass parameters to ret_from_kernel_thread:
	261	* a2 = thread_fn, a3 = thread_fn arg
	262	*/
	263	((int )childregs - 1) = thread_fn_arg;
	264	((int )childregs - 2) = usp_thread_fn;
	265
	266	/* Childregs are only used when we're going to userspace
	267	* in which case start_thread will set them up.
	268	*/
5a0015d6	269	}
c658eac6 CZ	270
	271	#if (XTENSA_HAVE_COPROCESSORS \|\| XTENSA_HAVE_IO_PORTS)
	272	ti = task_thread_info(p);
	273	ti->cpenable = 0;
	274	#endif
	275
5a0015d6 CZ	276	return 0;
	277	}
	278
	279
5a0015d6 CZ	280	/*
	281	* These bracket the sleeping functions..
	282	*/
	283
	284	unsigned long get_wchan(struct task_struct *p)
	285	{
	286	unsigned long sp, pc;
04fe6faf	287	unsigned long stack_page = (unsigned long) task_stack_page(p);
5a0015d6 CZ	288	int count = 0;
	289
	290	if (!p \|\| p == current \|\| p->state == TASK_RUNNING)
	291	return 0;
	292
	293	sp = p->thread.sp;
	294	pc = MAKE_PC_FROM_RA(p->thread.ra, p->thread.sp);
	295
	296	do {
	297	if (sp < stack_page + sizeof(struct task_struct) \|\|
	298	sp >= (stack_page + THREAD_SIZE) \|\|
	299	pc == 0)
	300	return 0;
	301	if (!in_sched_functions(pc))
	302	return pc;
	303
	304	/* Stack layout: sp-4: ra, sp-3: sp' */
	305
	306	pc = MAKE_PC_FROM_RA((unsigned long)sp - 4, sp);
	307	sp = (unsigned long )sp - 3;
	308	} while (count++ < 16);
	309	return 0;
	310	}
	311
	312	/*
5a0015d6 CZ	313	* xtensa_gregset_t and 'struct pt_regs' are vastly different formats
	314	* of processor registers. Besides different ordering,
	315	* xtensa_gregset_t contains non-live register information that
	316	* 'struct pt_regs' does not. Exception handling (primarily) uses
	317	* 'struct pt_regs'. Core files and ptrace use xtensa_gregset_t.
	318	*
	319	*/
	320
c658eac6	321	void xtensa_elf_core_copy_regs (xtensa_gregset_t elfregs, struct pt_regs regs)
5a0015d6	322	{
c658eac6 CZ	323	unsigned long wb, ws, wm;
	324	int live, last;
	325
	326	wb = regs->windowbase;
	327	ws = regs->windowstart;
	328	wm = regs->wmask;
	329	ws = ((ws >> wb) \| (ws << (WSBITS - wb))) & ((1 << WSBITS) - 1);
	330
	331	/* Don't leak any random bits. */
	332
688bb415	333	memset(elfregs, 0, sizeof(*elfregs));
c658eac6	334
5a0015d6 CZ	335	/* Note: PS.EXCM is not set while user task is running; its
	336	* being set in regs->ps is for exception handling convenience.
	337	*/
	338
	339	elfregs->pc = regs->pc;
173d6681	340	elfregs->ps = (regs->ps & ~(1 << PS_EXCM_BIT));
5a0015d6 CZ	341	elfregs->lbeg = regs->lbeg;
	342	elfregs->lend = regs->lend;
	343	elfregs->lcount = regs->lcount;
	344	elfregs->sar = regs->sar;
c658eac6	345	elfregs->windowstart = ws;
5a0015d6	346
c658eac6 CZ	347	live = (wm & 2) ? 4 : (wm & 4) ? 8 : (wm & 8) ? 12 : 16;
	348	last = XCHAL_NUM_AREGS - (wm >> 4) * 4;
	349	memcpy(elfregs->a, regs->areg, live * 4);
	350	memcpy(elfregs->a + last, regs->areg + last, (wm >> 4) * 16);
5a0015d6 CZ	351	}
5a0015d6 CZ	352
c658eac6	353	int dump_fpu(void)
5a0015d6	354	{
5a0015d6 CZ	355	return 0;
5a0015d6 CZ	356	}