/*
 * include/asm-parisc/processor.h
 *
 * Copyright (C) 1994 Linus Torvalds
 */

#ifndef __ASM_PARISC_PROCESSOR_H
#define __ASM_PARISC_PROCESSOR_H

#ifndef __ASSEMBLY__
#include <linux/threads.h>

#include <asm/hardware.h>
#include <asm/page.h>
#include <asm/pdc.h>
#include <asm/ptrace.h>
#include <asm/types.h>
#endif /* __ASSEMBLY__ */

/*
 * Default implementation of macro that returns current
 * instruction pointer ("program counter").
 */

/* We cannot use MFIA as it was added for PA2.0 - prumpf

   At one point there were no "0f/0b" type local symbols in gas for
   PA-RISC.  This is no longer true, but this still seems like the
   nicest way to implement this. */

#define current_text_addr() ({ void *pc; __asm__("\n\tblr 0,%0\n\tnop":"=r" (pc)); pc; })

#define TASK_SIZE           (PAGE_OFFSET)
#define TASK_UNMAPPED_BASE  (TASK_SIZE / 3)

#ifndef __ASSEMBLY__

/*
** Data detected about CPUs at boot time which is the same for all CPU's.
** HP boxes are SMP - ie identical processors.
**
** FIXME: some CPU rev info may be processor specific...
*/
struct system_cpuinfo_parisc {
        unsigned int    cpu_count;
        unsigned int    cpu_hz;
        unsigned int    hversion;
        unsigned int    sversion;
        enum cpu_type   cpu_type;

        struct {
                struct pdc_model model;
                struct pdc_model_cpuid /* ARGH */ versions;
                struct pdc_model_cpuid cpuid;
#if 0
                struct pdc_model_caps caps;
#endif
                char   sys_model_name[81]; /* PDC-ROM returnes this model name */
        } pdc;

        char            *model_name;
        char            *cpu_name;
        char            *family_name;
};


/*
** Per CPU data structure - ie varies per CPU.
*/
struct cpuinfo_parisc {
        unsigned cpuid;

        struct irq_region *region;

        unsigned long it_value; /* Interval Timer value at last timer interrupt */
        unsigned long it_delta; /* Interval Timer delta (tic_10ms / HZ * 100) */

        unsigned long hpa;      /* Host Physical address */
        unsigned long txn_addr; /* External Interrupt Register or id_eid */

        unsigned long bh_count;         /* number of times bh was invoked */
        unsigned long irq_count;        /* number of IRQ's since boot */
        unsigned long irq_max_cr16;     /* longest time to handle a single IRQ */
};

extern struct system_cpuinfo_parisc boot_cpu_data;
extern struct cpuinfo_parisc cpu_data[NR_CPUS];
#define current_cpu_data cpu_data[smp_processor_id()]

extern void identify_cpu(struct cpuinfo_parisc *);

#define EISA_bus 0 /* we don't have ISA support yet */
#define EISA_bus__is_a_macro /* for versions in ksyms.c */
#define MCA_bus 0
#define MCA_bus__is_a_macro /* for versions in ksyms.c */

typedef struct {
        int seg;  
} mm_segment_t;

struct thread_struct {
        struct pt_regs regs;
        unsigned long  pg_tables;
        unsigned long  flags;
}; 

/* Thread struct flags. */
#define PARISC_KERNEL_DEATH     (1UL << 31)     /* see die_if_kernel()... */

#define INIT_THREAD { {                 \
        { 0, 0, 0, 0, 0, 0, 0, 0,       \
          0, 0, 0, 0, 0, 0, 0, 0,       \
          0, 0, 0, 0, 0, 0, 0, 0,       \
          0, 0, 0, 0, 0, 0, 0, 0 },     \
        { 0, 0, 0, 0, 0, 0, 0, 0,       \
          0, 0, 0, 0, 0, 0, 0, 0,       \
          0, 0, 0, 0, 0, 0, 0, 0,       \
          0, 0, 0, 0, 0, 0, 0, 0 },     \
        { 0, 0, 0, 0, 0, 0, 0, 0 },     \
        { 0, 0}, { 0, 0}, 0, 0, 0, 0    \
        }, __pa((unsigned long) swapper_pg_dir) }

/*
 * Return saved PC of a blocked thread.  This is used by ps mostly.
 */

extern inline unsigned long thread_saved_pc(struct thread_struct *t)
{
        return 0xabcdef;
}

/*
 * Start user thread in another space.
 *
 * Note that we set both the iaoq and r31 to the new pc. When
 * the kernel initially calls execve it will return through an
 * rfi path that will use the values in the iaoq. The execve
 * syscall path will return through the gateway page, and
 * that uses r31 to branch to.
 *
 * For ELF we clear r23, because the dynamic linker uses it to pass
 * the address of the finalizer function.
 *
 * We also initialize sr3 to an illegal value (illegal for our
 * implementation, not for the architecture).
 */

/* The ELF abi wants things done a "wee bit" differently than
 * som does.  Supporting this behavior here avoids
 * having our own version of create_elf_tables.
 *
 * Oh, and yes, that is not a typo, we are really passing argc in r25
 * and argv in r24 (rather than r26 and r25).  This is because that's
 * where __libc_start_main wants them.
 *
 * Duplicated from dl-machine.h for the benefit of readers:
 *
 *  Our initial stack layout is rather different from everyone else's
 *  due to the unique PA-RISC ABI.  As far as I know it looks like
 *  this:

   -----------------------------------  (user startup code creates this frame)
   |         32 bytes of magic       |
   |---------------------------------|
   | 32 bytes argument/sp save area  |
   |---------------------------------|  ((current->mm->env_end) + 63 & ~63)
   |         N bytes of slack        |
   |---------------------------------|
   |      envvar and arg strings     |
   |---------------------------------|
   |        ELF auxiliary info       |
   |         (up to 28 words)        |
   |---------------------------------|
   |  Environment variable pointers  |
   |         upwards to NULL         |
   |---------------------------------|
   |        Argument pointers        |
   |         upwards to NULL         |
   |---------------------------------|
   |          argc (1 word)          |
   -----------------------------------

 *  The pleasant part of this is that if we need to skip arguments we
 *  can just decrement argc and move argv, because the stack pointer
 *  is utterly unrelated to the location of the environment and
 *  argument vectors.
 *
 * Note that the S/390 people took the easy way out and hacked their
 * GCC to make the stack grow downwards.  */

#define start_thread_som(regs, new_pc, new_sp) do {             \
        unsigned long *sp = (unsigned long *)new_sp;    \
        __u32 spaceid = (__u32)current->mm->context;    \
        unsigned long pc = (unsigned long)new_pc;       \
        /* offset pc for priv. level */                 \
        pc |= 3;                                        \
                                                        \
        set_fs(USER_DS);                                \
        regs->iasq[0] = spaceid;                        \
        regs->iasq[1] = spaceid;                        \
        regs->iaoq[0] = pc;                             \
        regs->iaoq[1] = pc;                             \
        regs->sr[2] = LINUX_GATEWAY_SPACE;              \
        regs->sr[3] = 0xffff;                           \
        regs->sr[4] = spaceid;                          \
        regs->sr[5] = spaceid;                          \
        regs->sr[6] = spaceid;                          \
        regs->sr[7] = spaceid;                          \
        regs->gr[ 0] = USER_INIT_PSW;                   \
        regs->gr[30] = ((new_sp)+63)&~63;               \
        regs->gr[31] = pc;                              \
                                                        \
        get_user(regs->gr[26],&sp[0]);                  \
        get_user(regs->gr[25],&sp[-1]);                 \
        get_user(regs->gr[24],&sp[-2]);                 \
        get_user(regs->gr[23],&sp[-3]);                 \
                                                        \
        regs->cr30 = (u32) current;                     \
} while(0)


#define start_thread(regs, new_pc, new_sp) do {         \
        unsigned long *sp = (unsigned long *)new_sp;    \
        __u32 spaceid = (__u32)current->mm->context;    \
        unsigned long pc = (unsigned long)new_pc;       \
        /* offset pc for priv. level */                 \
        pc |= 3;                                        \
                                                        \
                                                        \
        set_fs(USER_DS);                                \
        regs->iasq[0] = spaceid;                        \
        regs->iasq[1] = spaceid;                        \
        regs->iaoq[0] = pc;                             \
        regs->iaoq[1] = pc;                             \
        regs->sr[2] = LINUX_GATEWAY_SPACE;              \
        regs->sr[3] = 0xffff;                           \
        regs->sr[4] = spaceid;                          \
        regs->sr[5] = spaceid;                          \
        regs->sr[6] = spaceid;                          \
        regs->sr[7] = spaceid;                          \
        regs->gr[ 0] = USER_INIT_PSW;                   \
        regs->fr[ 0] = 0LL;                             \
        regs->fr[ 1] = 0LL;                             \
        regs->fr[ 2] = 0LL;                             \
        regs->fr[ 3] = 0LL;                             \
        regs->gr[30] = ((current->mm->env_end)+63)&~63; \
        regs->gr[31] = pc;                              \
                                                        \
        get_user(regs->gr[25],&sp[0]);                  \
        regs->gr[24] = (unsigned long) &sp[1];          \
        regs->gr[23] = 0;                               \
                                                        \
        regs->cr30 = (u32) current;                     \
} while(0)

#ifdef __LP64__

/*
 * For 64 bit kernels we need a version of start thread for 32 bit
 * elf files.
 *
 * FIXME: It should be possible to not duplicate the above code
 *        by playing games with concatenation to form both
 *        macros at compile time. The only difference between
 *        this macro and the above is the name and the types
 *        for sp and pc.
 */

#define start_thread32(regs, new_pc, new_sp) do {         \
        __u32 *sp = (__u32 *)new_sp;                    \
        __u32 spaceid = (__u32)current->mm->context;    \
        __u32 pc = (__u32)new_pc;                       \
        /* offset pc for priv. level */                 \
        pc |= 3;                                        \
                                                        \
        set_fs(USER_DS);                                \
        regs->iasq[0] = spaceid;                        \
        regs->iasq[1] = spaceid;                        \
        regs->iaoq[0] = pc;                             \
        regs->iaoq[1] = pc;                             \
        regs->sr[2] = LINUX_GATEWAY_SPACE;              \
        regs->sr[3] = 0xffff;                           \
        regs->sr[4] = spaceid;                          \
        regs->sr[5] = spaceid;                          \
        regs->sr[6] = spaceid;                          \
        regs->sr[7] = spaceid;                          \
        regs->gr[ 0] = USER_INIT_PSW;                   \
        regs->fr[ 0] = 0LL;                             \
        regs->fr[ 1] = 0LL;                             \
        regs->fr[ 2] = 0LL;                             \
        regs->fr[ 3] = 0LL;                             \
        regs->gr[30] = ((current->mm->env_end)+63)&~63; \
        regs->gr[31] = pc;                              \
                                                        \
        get_user(regs->gr[25],&sp[0]);                  \
        regs->gr[24] = (unsigned long) &sp[1];          \
        regs->gr[23] = 0;                               \
                                                        \
        regs->cr30 = (u32) current;                     \
} while(0)

#endif

struct task_struct;

/* 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);

#define copy_segments(tsk, mm)  do { } while (0)
#define release_segments(mm)    do { } while (0)

extern inline unsigned long get_wchan(struct task_struct *p)
{
        return 0xdeadbeef; /* XXX */
}

#define KSTK_EIP(tsk)   (0xdeadbeef)
#define KSTK_ESP(tsk)   (0xdeadbeef)

/* Be sure to hunt all references to this down when you change the size of
 * the kernel stack */

#endif /* __ASSEMBLY__ */

#define THREAD_SIZE     (4*PAGE_SIZE)

#define alloc_task_struct() \
        ((struct task_struct *) __get_free_pages(GFP_KERNEL,2))
#define free_task_struct(p)     free_pages((unsigned long)(p),2)
#define get_task_struct(tsk)      atomic_inc(&virt_to_page(tsk)->count)

#define init_task (init_task_union.task) 
#define init_stack (init_task_union.stack)

#define cpu_relax()     do { } while (0)


#endif /* __ASM_PARISC_PROCESSOR_H */