/*
 *  include/asm-s390/processor.h
 *
 *  S390 version
 *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
 *    Author(s): Hartmut Penner (hp@de.ibm.com),
 *               Martin Schwidefsky (schwidefsky@de.ibm.com)
 *
 *  Derived from "include/asm-i386/processor.h"
 *    Copyright (C) 1994, Linus Torvalds
 */

#ifndef __ASM_S390_PROCESSOR_H
#define __ASM_S390_PROCESSOR_H

#include <linux/linkage.h>
#include <asm/cpu.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#include <asm/setup.h>

#ifdef __KERNEL__
/*
 * Default implementation of macro that returns current
 * instruction pointer ("program counter").
 */
#define current_text_addr() ({ void *pc; asm("basr %0,0" : "=a" (pc)); pc; })

static inline void get_cpu_id(struct cpuid *ptr)
{
        asm volatile("stidp 0(%1)" : "=m" (*ptr) : "a" (ptr));
}

extern void s390_adjust_jiffies(void);
extern void print_cpu_info(void);
extern int get_cpu_capability(unsigned int *);

/*
 * User space process size: 2GB for 31 bit, 4TB or 8PT for 64 bit.
 */
#ifndef __s390x__

#define TASK_SIZE               (1UL << 31)
#define TASK_UNMAPPED_BASE      (1UL << 30)

#else /* __s390x__ */

#define TASK_SIZE_OF(tsk)       ((tsk)->mm->context.asce_limit)
#define TASK_UNMAPPED_BASE      (test_thread_flag(TIF_31BIT) ? \
                                        (1UL << 30) : (1UL << 41))
#define TASK_SIZE               TASK_SIZE_OF(current)

#endif /* __s390x__ */

#ifdef __KERNEL__

#ifndef __s390x__
#define STACK_TOP               (1UL << 31)
#define STACK_TOP_MAX           (1UL << 31)
#else /* __s390x__ */
#define STACK_TOP               (1UL << (test_thread_flag(TIF_31BIT) ? 31:42))
#define STACK_TOP_MAX           (1UL << 42)
#endif /* __s390x__ */


#endif

#define HAVE_ARCH_PICK_MMAP_LAYOUT

typedef struct {
        __u32 ar4;
} mm_segment_t;

/*
 * Thread structure
 */
struct thread_struct {
        s390_fp_regs fp_regs;
        unsigned int  acrs[NUM_ACRS];
        unsigned long ksp;              /* kernel stack pointer             */
        mm_segment_t mm_segment;
        unsigned long prot_addr;        /* address of protection-excep.     */
        unsigned int trap_no;
        per_struct per_info;
        /* Used to give failing instruction back to user for ieee exceptions */
        unsigned long ieee_instruction_pointer; 
        /* pfault_wait is used to block the process on a pfault event */
        unsigned long pfault_wait;
};

typedef struct thread_struct thread_struct;

/*
 * Stack layout of a C stack frame.
 */
#ifndef __PACK_STACK
struct stack_frame {
        unsigned long back_chain;
        unsigned long empty1[5];
        unsigned long gprs[10];
        unsigned int  empty2[8];
};
#else
struct stack_frame {
        unsigned long empty1[5];
        unsigned int  empty2[8];
        unsigned long gprs[10];
        unsigned long back_chain;
};
#endif

#define ARCH_MIN_TASKALIGN      8

#define INIT_THREAD {                                                   \
        .ksp = sizeof(init_stack) + (unsigned long) &init_stack,        \
}

/*
 * Do necessary setup to start up a new thread.
 */
#define start_thread(regs, new_psw, new_stackp) do {            \
        set_fs(USER_DS);                                        \
        regs->psw.mask  = psw_user_bits;                        \
        regs->psw.addr  = new_psw | PSW_ADDR_AMODE;             \
        regs->gprs[15]  = new_stackp;                           \
} while (0)

#define start_thread31(regs, new_psw, new_stackp) do {          \
        set_fs(USER_DS);                                        \
        regs->psw.mask  = psw_user32_bits;                      \
        regs->psw.addr  = new_psw | PSW_ADDR_AMODE;             \
        regs->gprs[15]  = new_stackp;                           \
        crst_table_downgrade(current->mm, 1UL << 31);           \
} while (0)

/* Forward declaration, a strange C thing */
struct task_struct;
struct mm_struct;
struct seq_file;

/* Free all resources held by a thread. */
extern void release_thread(struct task_struct *);
extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);

/* Prepare to copy thread state - unlazy all lazy status */
#define prepare_to_copy(tsk)    do { } while (0)

/*
 * Return saved PC of a blocked thread.
 */
extern unsigned long thread_saved_pc(struct task_struct *t);

/*
 * Print register of task into buffer. Used in fs/proc/array.c.
 */
extern void task_show_regs(struct seq_file *m, struct task_struct *task);

extern void show_code(struct pt_regs *regs);

unsigned long get_wchan(struct task_struct *p);
#define task_pt_regs(tsk) ((struct pt_regs *) \
        (task_stack_page(tsk) + THREAD_SIZE) - 1)
#define KSTK_EIP(tsk)   (task_pt_regs(tsk)->psw.addr)
#define KSTK_ESP(tsk)   (task_pt_regs(tsk)->gprs[15])

/*
 * Give up the time slice of the virtual PU.
 */
static inline void cpu_relax(void)
{
        if (MACHINE_HAS_DIAG44)
                asm volatile("diag 0,0,68");
        barrier();
}

static inline void psw_set_key(unsigned int key)
{
        asm volatile("spka 0(%0)" : : "d" (key));
}

/*
 * Set PSW to specified value.
 */
static inline void __load_psw(psw_t psw)
{
#ifndef __s390x__
        asm volatile("lpsw  0(%0)" : : "a" (&psw), "m" (psw) : "cc");
#else
        asm volatile("lpswe 0(%0)" : : "a" (&psw), "m" (psw) : "cc");
#endif
}

/*
 * Set PSW mask to specified value, while leaving the
 * PSW addr pointing to the next instruction.
 */

static inline void __load_psw_mask (unsigned long mask)
{
        unsigned long addr;
        psw_t psw;

        psw.mask = mask;

#ifndef __s390x__
        asm volatile(
                "       basr    %0,0\n"
                "0:     ahi     %0,1f-0b\n"
                "       st      %0,4(%1)\n"
                "       lpsw    0(%1)\n"
                "1:"
                : "=&d" (addr) : "a" (&psw), "m" (psw) : "memory", "cc");
#else /* __s390x__ */
        asm volatile(
                "       larl    %0,1f\n"
                "       stg     %0,8(%1)\n"
                "       lpswe   0(%1)\n"
                "1:"
                : "=&d" (addr) : "a" (&psw), "m" (psw) : "memory", "cc");
#endif /* __s390x__ */
}
 
/*
 * Function to stop a processor until an interruption occurred
 */
static inline void enabled_wait(void)
{
        __load_psw_mask(PSW_BASE_BITS | PSW_MASK_IO | PSW_MASK_EXT |
                        PSW_MASK_MCHECK | PSW_MASK_WAIT | PSW_DEFAULT_KEY);
}

/*
 * Function to drop a processor into disabled wait state
 */

static inline void ATTRIB_NORET disabled_wait(unsigned long code)
{
        unsigned long ctl_buf;
        psw_t dw_psw;

        dw_psw.mask = PSW_BASE_BITS | PSW_MASK_WAIT;
        dw_psw.addr = code;
        /* 
         * Store status and then load disabled wait psw,
         * the processor is dead afterwards
         */
#ifndef __s390x__
        asm volatile(
                "       stctl   0,0,0(%2)\n"
                "       ni      0(%2),0xef\n"   /* switch off protection */
                "       lctl    0,0,0(%2)\n"
                "       stpt    0xd8\n"         /* store timer */
                "       stckc   0xe0\n"         /* store clock comparator */
                "       stpx    0x108\n"        /* store prefix register */
                "       stam    0,15,0x120\n"   /* store access registers */
                "       std     0,0x160\n"      /* store f0 */
                "       std     2,0x168\n"      /* store f2 */
                "       std     4,0x170\n"      /* store f4 */
                "       std     6,0x178\n"      /* store f6 */
                "       stm     0,15,0x180\n"   /* store general registers */
                "       stctl   0,15,0x1c0\n"   /* store control registers */
                "       oi      0x1c0,0x10\n"   /* fake protection bit */
                "       lpsw    0(%1)"
                : "=m" (ctl_buf)
                : "a" (&dw_psw), "a" (&ctl_buf), "m" (dw_psw) : "cc");
#else /* __s390x__ */
        asm volatile(
                "       stctg   0,0,0(%2)\n"
                "       ni      4(%2),0xef\n"   /* switch off protection */
                "       lctlg   0,0,0(%2)\n"
                "       lghi    1,0x1000\n"
                "       stpt    0x328(1)\n"     /* store timer */
                "       stckc   0x330(1)\n"     /* store clock comparator */
                "       stpx    0x318(1)\n"     /* store prefix register */
                "       stam    0,15,0x340(1)\n"/* store access registers */
                "       stfpc   0x31c(1)\n"     /* store fpu control */
                "       std     0,0x200(1)\n"   /* store f0 */
                "       std     1,0x208(1)\n"   /* store f1 */
                "       std     2,0x210(1)\n"   /* store f2 */
                "       std     3,0x218(1)\n"   /* store f3 */
                "       std     4,0x220(1)\n"   /* store f4 */
                "       std     5,0x228(1)\n"   /* store f5 */
                "       std     6,0x230(1)\n"   /* store f6 */
                "       std     7,0x238(1)\n"   /* store f7 */
                "       std     8,0x240(1)\n"   /* store f8 */
                "       std     9,0x248(1)\n"   /* store f9 */
                "       std     10,0x250(1)\n"  /* store f10 */
                "       std     11,0x258(1)\n"  /* store f11 */
                "       std     12,0x260(1)\n"  /* store f12 */
                "       std     13,0x268(1)\n"  /* store f13 */
                "       std     14,0x270(1)\n"  /* store f14 */
                "       std     15,0x278(1)\n"  /* store f15 */
                "       stmg    0,15,0x280(1)\n"/* store general registers */
                "       stctg   0,15,0x380(1)\n"/* store control registers */
                "       oi      0x384(1),0x10\n"/* fake protection bit */
                "       lpswe   0(%1)"
                : "=m" (ctl_buf)
                : "a" (&dw_psw), "a" (&ctl_buf), "m" (dw_psw) : "cc", "0", "1");
#endif /* __s390x__ */
        while (1);
}

/*
 * Basic Machine Check/Program Check Handler.
 */

extern void s390_base_mcck_handler(void);
extern void s390_base_pgm_handler(void);
extern void s390_base_ext_handler(void);

extern void (*s390_base_mcck_handler_fn)(void);
extern void (*s390_base_pgm_handler_fn)(void);
extern void (*s390_base_ext_handler_fn)(void);

#define ARCH_LOW_ADDRESS_LIMIT  0x7fffffffUL

#endif

/*
 * Helper macro for exception table entries
 */
#ifndef __s390x__
#define EX_TABLE(_fault,_target)                        \
        ".section __ex_table,\"a\"\n"                   \
        "       .align 4\n"                             \
        "       .long  " #_fault "," #_target "\n"      \
        ".previous\n"
#else
#define EX_TABLE(_fault,_target)                        \
        ".section __ex_table,\"a\"\n"                   \
        "       .align 8\n"                             \
        "       .quad  " #_fault "," #_target "\n"      \
        ".previous\n"
#endif

#endif                                 /* __ASM_S390_PROCESSOR_H           */