/*
* Process/processor support for the Hexagon architecture
*
* Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/

#ifndef _ASM_PROCESSOR_H
#define _ASM_PROCESSOR_H

#ifndef __ASSEMBLY__

#include <asm/mem-layout.h>
#include <asm/registers.h>
#include <asm/hexagon_vm.h>

/* must be a macro */
#define current_text_addr() ({ __label__ _l; _l: &&_l; })

/* task_struct, defined elsewhere, is the "process descriptor" */
struct task_struct;

/* this is defined in arch/process.c */
extern unsigned long thread_saved_pc(struct task_struct *tsk);

extern void start_thread(struct pt_regs *, unsigned long, unsigned long);

/*
* thread_struct is supposed to be for context switch data.
* Specifically, to hold the state necessary to perform switch_to...
*/
struct thread_struct {
void *switch_sp;
};

/*
* initializes thread_struct
* The only thing we have in there is switch_sp
* which doesn't really need to be initialized.
*/

#define INIT_THREAD { \
}

#define cpu_relax() __vmyield()

/*
* Decides where the kernel will search for a free chunk of vm space during
* mmaps.
* See also arch_get_unmapped_area.
* Doesn't affect if you have MAX_FIXED in the page flags set though...
*
* Apparently the convention is that ld.so will ask for "unmapped" private
* memory to be allocated SOMEWHERE, but it also asks for memory explicitly
* via MAP_FIXED at the lower * addresses starting at VA=0x0.
*
* If the two requests collide, you get authentic segfaulting action, so
* you have to kick the "unmapped" base requests higher up.
*/
#define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE/3))


#define task_pt_regs(task) \
((struct pt_regs *)(task_stack_page(task) + THREAD_SIZE) - 1)

#define KSTK_EIP(tsk) (pt_elr(task_pt_regs(tsk)))
#define KSTK_ESP(tsk) (pt_psp(task_pt_regs(tsk)))

/* Free all resources held by a thread; defined in process.c */
extern void release_thread(struct task_struct *dead_task);

/* Get wait channel for task P. */
extern unsigned long get_wchan(struct task_struct *p);

/* The following stuff is pretty HEXAGON specific. */

/* This is really just here for __switch_to.
Offsets are pulled via asm-offsets.c */

/*
* No real reason why VM and native switch stacks should be different.
* Ultimately this should merge. Note that Rev C. ABI called out only
* R24-27 as callee saved GPRs needing explicit attention (R29-31 being
* dealt with automagically by allocframe), but the current ABI has
* more, R16-R27. By saving more, the worst case is that we waste some
* cycles if building with the old compilers.
*/

struct hexagon_switch_stack {
union {
struct {
unsigned long r16;
unsigned long r17;
};
unsigned long long r1716;
};
union {
struct {
unsigned long r18;
unsigned long r19;
};
unsigned long long r1918;
};
union {
struct {
unsigned long r20;
unsigned long r21;
};
unsigned long long r2120;
};
union {
struct {
unsigned long r22;
unsigned long r23;
};
unsigned long long r2322;
};
union {
struct {
unsigned long r24;
unsigned long r25;
};
unsigned long long r2524;
};
union {
struct {
unsigned long r26;
unsigned long r27;
};
unsigned long long r2726;
};

unsigned long fp;
unsigned long lr;
};

#endif /* !__ASSEMBLY__ */

#endif