/* linux/arch/sparc64/kernel/sys_sparc.c
 *
 * This file contains various random system calls that
 * have a non-standard calling sequence on the Linux/sparc
 * platform.
 */

#include <linux/errno.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mm.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/stat.h>
#include <linux/mman.h>
#include <linux/utsname.h>
#include <linux/smp.h>
#include <linux/slab.h>
#include <linux/syscalls.h>
#include <linux/ipc.h>
#include <linux/personality.h>
#include <linux/random.h>
#include <linux/module.h>

#include <asm/uaccess.h>
#include <asm/utrap.h>
#include <asm/perfctr.h>
#include <asm/unistd.h>

#include "entry.h"
#include "systbls.h"

/* #define DEBUG_UNIMP_SYSCALL */

asmlinkage unsigned long sys_getpagesize(void)
{
        return PAGE_SIZE;
}

#define VA_EXCLUDE_START (0x0000080000000000UL - (1UL << 32UL))
#define VA_EXCLUDE_END   (0xfffff80000000000UL + (1UL << 32UL))

/* Does addr --> addr+len fall within 4GB of the VA-space hole or
 * overflow past the end of the 64-bit address space?
 */
static inline int invalid_64bit_range(unsigned long addr, unsigned long len)
{
        unsigned long va_exclude_start, va_exclude_end;

        va_exclude_start = VA_EXCLUDE_START;
        va_exclude_end   = VA_EXCLUDE_END;

        if (unlikely(len >= va_exclude_start))
                return 1;

        if (unlikely((addr + len) < addr))
                return 1;

        if (unlikely((addr >= va_exclude_start && addr < va_exclude_end) ||
                     ((addr + len) >= va_exclude_start &&
                      (addr + len) < va_exclude_end)))
                return 1;

        return 0;
}

/* Does start,end straddle the VA-space hole?  */
static inline int straddles_64bit_va_hole(unsigned long start, unsigned long end)
{
        unsigned long va_exclude_start, va_exclude_end;

        va_exclude_start = VA_EXCLUDE_START;
        va_exclude_end   = VA_EXCLUDE_END;

        if (likely(start < va_exclude_start && end < va_exclude_start))
                return 0;

        if (likely(start >= va_exclude_end && end >= va_exclude_end))
                return 0;

        return 1;
}

/* These functions differ from the default implementations in
 * mm/mmap.c in two ways:
 *
 * 1) For file backed MAP_SHARED mmap()'s we D-cache color align,
 *    for fixed such mappings we just validate what the user gave us.
 * 2) For 64-bit tasks we avoid mapping anything within 4GB of
 *    the spitfire/niagara VA-hole.
 */

static inline unsigned long COLOUR_ALIGN(unsigned long addr,
                                         unsigned long pgoff)
{
        unsigned long base = (addr+SHMLBA-1)&~(SHMLBA-1);
        unsigned long off = (pgoff<<PAGE_SHIFT) & (SHMLBA-1);

        return base + off;
}

static inline unsigned long COLOUR_ALIGN_DOWN(unsigned long addr,
                                              unsigned long pgoff)
{
        unsigned long base = addr & ~(SHMLBA-1);
        unsigned long off = (pgoff<<PAGE_SHIFT) & (SHMLBA-1);

        if (base + off <= addr)
                return base + off;
        return base - off;
}

unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags)
{
        struct mm_struct *mm = current->mm;
        struct vm_area_struct * vma;
        unsigned long task_size = TASK_SIZE;
        unsigned long start_addr;
        int do_color_align;

        if (flags & MAP_FIXED) {
                /* We do not accept a shared mapping if it would violate
                 * cache aliasing constraints.
                 */
                if ((flags & MAP_SHARED) &&
                    ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
                        return -EINVAL;
                return addr;
        }

        if (test_thread_flag(TIF_32BIT))
                task_size = STACK_TOP32;
        if (unlikely(len > task_size || len >= VA_EXCLUDE_START))
                return -ENOMEM;

        do_color_align = 0;
        if (filp || (flags & MAP_SHARED))
                do_color_align = 1;

        if (addr) {
                if (do_color_align)
                        addr = COLOUR_ALIGN(addr, pgoff);
                else
                        addr = PAGE_ALIGN(addr);

                vma = find_vma(mm, addr);
                if (task_size - len >= addr &&
                    (!vma || addr + len <= vma->vm_start))
                        return addr;
        }

        if (len > mm->cached_hole_size) {
                start_addr = addr = mm->free_area_cache;
        } else {
                start_addr = addr = TASK_UNMAPPED_BASE;
                mm->cached_hole_size = 0;
        }

        task_size -= len;

full_search:
        if (do_color_align)
                addr = COLOUR_ALIGN(addr, pgoff);
        else
                addr = PAGE_ALIGN(addr);

        for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
                /* At this point:  (!vma || addr < vma->vm_end). */
                if (addr < VA_EXCLUDE_START &&
                    (addr + len) >= VA_EXCLUDE_START) {
                        addr = VA_EXCLUDE_END;
                        vma = find_vma(mm, VA_EXCLUDE_END);
                }
                if (unlikely(task_size < addr)) {
                        if (start_addr != TASK_UNMAPPED_BASE) {
                                start_addr = addr = TASK_UNMAPPED_BASE;
                                mm->cached_hole_size = 0;
                                goto full_search;
                        }
                        return -ENOMEM;
                }
                if (likely(!vma || addr + len <= vma->vm_start)) {
                        /*
                         * Remember the place where we stopped the search:
                         */
                        mm->free_area_cache = addr + len;
                        return addr;
                }
                if (addr + mm->cached_hole_size < vma->vm_start)
                        mm->cached_hole_size = vma->vm_start - addr;

                addr = vma->vm_end;
                if (do_color_align)
                        addr = COLOUR_ALIGN(addr, pgoff);
        }
}

unsigned long
arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
                          const unsigned long len, const unsigned long pgoff,
                          const unsigned long flags)
{
        struct vm_area_struct *vma;
        struct mm_struct *mm = current->mm;
        unsigned long task_size = STACK_TOP32;
        unsigned long addr = addr0;
        int do_color_align;

        /* This should only ever run for 32-bit processes.  */
        BUG_ON(!test_thread_flag(TIF_32BIT));

        if (flags & MAP_FIXED) {
                /* We do not accept a shared mapping if it would violate
                 * cache aliasing constraints.
                 */
                if ((flags & MAP_SHARED) &&
                    ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
                        return -EINVAL;
                return addr;
        }

        if (unlikely(len > task_size))
                return -ENOMEM;

        do_color_align = 0;
        if (filp || (flags & MAP_SHARED))
                do_color_align = 1;

        /* requesting a specific address */
        if (addr) {
                if (do_color_align)
                        addr = COLOUR_ALIGN(addr, pgoff);
                else
                        addr = PAGE_ALIGN(addr);

                vma = find_vma(mm, addr);
                if (task_size - len >= addr &&
                    (!vma || addr + len <= vma->vm_start))
                        return addr;
        }

        /* check if free_area_cache is useful for us */
        if (len <= mm->cached_hole_size) {
                mm->cached_hole_size = 0;
                mm->free_area_cache = mm->mmap_base;
        }

        /* either no address requested or can't fit in requested address hole */
        addr = mm->free_area_cache;
        if (do_color_align) {
                unsigned long base = COLOUR_ALIGN_DOWN(addr-len, pgoff);

                addr = base + len;
        }

        /* make sure it can fit in the remaining address space */
        if (likely(addr > len)) {
                vma = find_vma(mm, addr-len);
                if (!vma || addr <= vma->vm_start) {
                        /* remember the address as a hint for next time */
                        return (mm->free_area_cache = addr-len);
                }
        }

        if (unlikely(mm->mmap_base < len))
                goto bottomup;

        addr = mm->mmap_base-len;
        if (do_color_align)
                addr = COLOUR_ALIGN_DOWN(addr, pgoff);

        do {
                /*
                 * Lookup failure means no vma is above this address,
                 * else if new region fits below vma->vm_start,
                 * return with success:
                 */
                vma = find_vma(mm, addr);
                if (likely(!vma || addr+len <= vma->vm_start)) {
                        /* remember the address as a hint for next time */
                        return (mm->free_area_cache = addr);
                }

                /* remember the largest hole we saw so far */
                if (addr + mm->cached_hole_size < vma->vm_start)
                        mm->cached_hole_size = vma->vm_start - addr;

                /* try just below the current vma->vm_start */
                addr = vma->vm_start-len;
                if (do_color_align)
                        addr = COLOUR_ALIGN_DOWN(addr, pgoff);
        } while (likely(len < vma->vm_start));

bottomup:
        /*
         * A failed mmap() very likely causes application failure,
         * so fall back to the bottom-up function here. This scenario
         * can happen with large stack limits and large mmap()
         * allocations.
         */
        mm->cached_hole_size = ~0UL;
        mm->free_area_cache = TASK_UNMAPPED_BASE;
        addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
        /*
         * Restore the topdown base:
         */
        mm->free_area_cache = mm->mmap_base;
        mm->cached_hole_size = ~0UL;

        return addr;
}

/* Try to align mapping such that we align it as much as possible. */
unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, unsigned long len, unsigned long pgoff, unsigned long flags)
{
        unsigned long align_goal, addr = -ENOMEM;

        if (flags & MAP_FIXED) {
                /* Ok, don't mess with it. */
                return get_unmapped_area(NULL, orig_addr, len, pgoff, flags);
        }
        flags &= ~MAP_SHARED;

        align_goal = PAGE_SIZE;
        if (len >= (4UL * 1024 * 1024))
                align_goal = (4UL * 1024 * 1024);
        else if (len >= (512UL * 1024))
                align_goal = (512UL * 1024);
        else if (len >= (64UL * 1024))
                align_goal = (64UL * 1024);

        do {
                addr = get_unmapped_area(NULL, orig_addr, len + (align_goal - PAGE_SIZE), pgoff, flags);
                if (!(addr & ~PAGE_MASK)) {
                        addr = (addr + (align_goal - 1UL)) & ~(align_goal - 1UL);
                        break;
                }

                if (align_goal == (4UL * 1024 * 1024))
                        align_goal = (512UL * 1024);
                else if (align_goal == (512UL * 1024))
                        align_goal = (64UL * 1024);
                else
                        align_goal = PAGE_SIZE;
        } while ((addr & ~PAGE_MASK) && align_goal > PAGE_SIZE);

        /* Mapping is smaller than 64K or larger areas could not
         * be obtained.
         */
        if (addr & ~PAGE_MASK)
                addr = get_unmapped_area(NULL, orig_addr, len, pgoff, flags);

        return addr;
}
EXPORT_SYMBOL(get_fb_unmapped_area);

/* Essentially the same as PowerPC... */
void arch_pick_mmap_layout(struct mm_struct *mm)
{
        unsigned long random_factor = 0UL;

        if (current->flags & PF_RANDOMIZE) {
                random_factor = get_random_int();
                if (test_thread_flag(TIF_32BIT))
                        random_factor &= ((1 * 1024 * 1024) - 1);
                else
                        random_factor = ((random_factor << PAGE_SHIFT) &
                                         0xffffffffUL);
        }

        /*
         * Fall back to the standard layout if the personality
         * bit is set, or if the expected stack growth is unlimited:
         */
        if (!test_thread_flag(TIF_32BIT) ||
            (current->personality & ADDR_COMPAT_LAYOUT) ||
            current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY ||
            sysctl_legacy_va_layout) {
                mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
                mm->get_unmapped_area = arch_get_unmapped_area;
                mm->unmap_area = arch_unmap_area;
        } else {
                /* We know it's 32-bit */
                unsigned long task_size = STACK_TOP32;
                unsigned long gap;

                gap = current->signal->rlim[RLIMIT_STACK].rlim_cur;
                if (gap < 128 * 1024 * 1024)
                        gap = 128 * 1024 * 1024;
                if (gap > (task_size / 6 * 5))
                        gap = (task_size / 6 * 5);

                mm->mmap_base = PAGE_ALIGN(task_size - gap - random_factor);
                mm->get_unmapped_area = arch_get_unmapped_area_topdown;
                mm->unmap_area = arch_unmap_area_topdown;
        }
}

SYSCALL_DEFINE1(sparc_brk, unsigned long, brk)
{
        /* People could try to be nasty and use ta 0x6d in 32bit programs */
        if (test_thread_flag(TIF_32BIT) && brk >= STACK_TOP32)
                return current->mm->brk;

        if (unlikely(straddles_64bit_va_hole(current->mm->brk, brk)))
                return current->mm->brk;

        return sys_brk(brk);
}
                                                                
/*
 * sys_pipe() is the normal C calling standard for creating
 * a pipe. It's not the way unix traditionally does this, though.
 */
SYSCALL_DEFINE1(sparc_pipe_real, struct pt_regs *, regs)
{
        int fd[2];
        int error;

        error = do_pipe_flags(fd, 0);
        if (error)
                goto out;
        regs->u_regs[UREG_I1] = fd[1];
        error = fd[0];
out:
        return error;
}

/*
 * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 *
 * This is really horribly ugly.
 */

SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
                unsigned long, third, void __user *, ptr, long, fifth)
{
        long err;

        /* No need for backward compatibility. We can start fresh... */
        if (call <= SEMCTL) {
                switch (call) {
                case SEMOP:
                        err = sys_semtimedop(first, ptr,
                                             (unsigned)second, NULL);
                        goto out;
                case SEMTIMEDOP:
                        err = sys_semtimedop(first, ptr, (unsigned)second,
                                (const struct timespec __user *)
                                             (unsigned long) fifth);
                        goto out;
                case SEMGET:
                        err = sys_semget(first, (int)second, (int)third);
                        goto out;
                case SEMCTL: {
                        err = sys_semctl(first, second,
                                         (int)third | IPC_64,
                                         (union semun) ptr);
                        goto out;
                }
                default:
                        err = -ENOSYS;
                        goto out;
                };
        }
        if (call <= MSGCTL) {
                switch (call) {
                case MSGSND:
                        err = sys_msgsnd(first, ptr, (size_t)second,
                                         (int)third);
                        goto out;
                case MSGRCV:
                        err = sys_msgrcv(first, ptr, (size_t)second, fifth,
                                         (int)third);
                        goto out;
                case MSGGET:
                        err = sys_msgget((key_t)first, (int)second);
                        goto out;
                case MSGCTL:
                        err = sys_msgctl(first, (int)second | IPC_64, ptr);
                        goto out;
                default:
                        err = -ENOSYS;
                        goto out;
                };
        }
        if (call <= SHMCTL) {
                switch (call) {
                case SHMAT: {
                        ulong raddr;
                        err = do_shmat(first, ptr, (int)second, &raddr);
                        if (!err) {
                                if (put_user(raddr,
                                             (ulong __user *) third))
                                        err = -EFAULT;
                        }
                        goto out;
                }
                case SHMDT:
                        err = sys_shmdt(ptr);
                        goto out;
                case SHMGET:
                        err = sys_shmget(first, (size_t)second, (int)third);
                        goto out;
                case SHMCTL:
                        err = sys_shmctl(first, (int)second | IPC_64, ptr);
                        goto out;
                default:
                        err = -ENOSYS;
                        goto out;
                };
        } else {
                err = -ENOSYS;
        }
out:
        return err;
}

SYSCALL_DEFINE1(sparc64_newuname, struct new_utsname __user *, name)
{
        int ret = sys_newuname(name);
        
        if (current->personality == PER_LINUX32 && !ret) {
                ret = (copy_to_user(name->machine, "sparc\0\0", 8)
                       ? -EFAULT : 0);
        }
        return ret;
}

SYSCALL_DEFINE1(sparc64_personality, unsigned long, personality)
{
        int ret;

        if (current->personality == PER_LINUX32 &&
            personality == PER_LINUX)
                personality = PER_LINUX32;
        ret = sys_personality(personality);
        if (ret == PER_LINUX32)
                ret = PER_LINUX;

        return ret;
}

int sparc_mmap_check(unsigned long addr, unsigned long len)
{
        if (test_thread_flag(TIF_32BIT)) {
                if (len >= STACK_TOP32)
                        return -EINVAL;

                if (addr > STACK_TOP32 - len)
                        return -EINVAL;
        } else {
                if (len >= VA_EXCLUDE_START)
                        return -EINVAL;

                if (invalid_64bit_range(addr, len))
                        return -EINVAL;
        }

        return 0;
}

/* Linux version of mmap */
SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
                unsigned long, prot, unsigned long, flags, unsigned long, fd,
                unsigned long, off)
{
        struct file * file = NULL;
        unsigned long retval = -EBADF;

        if (!(flags & MAP_ANONYMOUS)) {
                file = fget(fd);
                if (!file)
                        goto out;
        }
        flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
        len = PAGE_ALIGN(len);

        down_write(&current->mm->mmap_sem);
        retval = do_mmap(file, addr, len, prot, flags, off);
        up_write(&current->mm->mmap_sem);

        if (file)
                fput(file);
out:
        return retval;
}

SYSCALL_DEFINE2(64_munmap, unsigned long, addr, size_t, len)
{
        long ret;

        if (invalid_64bit_range(addr, len))
                return -EINVAL;

        down_write(&current->mm->mmap_sem);
        ret = do_munmap(current->mm, addr, len);
        up_write(&current->mm->mmap_sem);
        return ret;
}

extern unsigned long do_mremap(unsigned long addr,
        unsigned long old_len, unsigned long new_len,
        unsigned long flags, unsigned long new_addr);
                
SYSCALL_DEFINE5(64_mremap, unsigned long, addr, unsigned long, old_len,
                unsigned long, new_len, unsigned long, flags,
                unsigned long, new_addr)
{
        unsigned long ret = -EINVAL;

        if (test_thread_flag(TIF_32BIT))
                goto out;
        if (unlikely(new_len >= VA_EXCLUDE_START))
                goto out;
        if (unlikely(sparc_mmap_check(addr, old_len)))
                goto out;
        if (unlikely(sparc_mmap_check(new_addr, new_len)))
                goto out;

        down_write(&current->mm->mmap_sem);
        ret = do_mremap(addr, old_len, new_len, flags, new_addr);
        up_write(&current->mm->mmap_sem);
out:
        return ret;       
}

/* we come to here via sys_nis_syscall so it can setup the regs argument */
asmlinkage unsigned long c_sys_nis_syscall(struct pt_regs *regs)
{
        static int count;
        
        /* Don't make the system unusable, if someone goes stuck */
        if (count++ > 5)
                return -ENOSYS;

        printk ("Unimplemented SPARC system call %ld\n",regs->u_regs[1]);
#ifdef DEBUG_UNIMP_SYSCALL      
        show_regs (regs);
#endif

        return -ENOSYS;
}

/* #define DEBUG_SPARC_BREAKPOINT */

asmlinkage void sparc_breakpoint(struct pt_regs *regs)
{
        siginfo_t info;

        if (test_thread_flag(TIF_32BIT)) {
                regs->tpc &= 0xffffffff;
                regs->tnpc &= 0xffffffff;
        }
#ifdef DEBUG_SPARC_BREAKPOINT
        printk ("TRAP: Entering kernel PC=%lx, nPC=%lx\n", regs->tpc, regs->tnpc);
#endif
        info.si_signo = SIGTRAP;
        info.si_errno = 0;
        info.si_code = TRAP_BRKPT;
        info.si_addr = (void __user *)regs->tpc;
        info.si_trapno = 0;
        force_sig_info(SIGTRAP, &info, current);
#ifdef DEBUG_SPARC_BREAKPOINT
        printk ("TRAP: Returning to space: PC=%lx nPC=%lx\n", regs->tpc, regs->tnpc);
#endif
}

extern void check_pending(int signum);

SYSCALL_DEFINE2(getdomainname, char __user *, name, int, len)
{
        int nlen, err;

        if (len < 0)
                return -EINVAL;

        down_read(&uts_sem);
        
        nlen = strlen(utsname()->domainname) + 1;
        err = -EINVAL;
        if (nlen > len)
                goto out;

        err = -EFAULT;
        if (!copy_to_user(name, utsname()->domainname, nlen))
                err = 0;

out:
        up_read(&uts_sem);
        return err;
}

SYSCALL_DEFINE5(utrap_install, utrap_entry_t, type,
                utrap_handler_t, new_p, utrap_handler_t, new_d,
                utrap_handler_t __user *, old_p,
                utrap_handler_t __user *, old_d)
{
        if (type < UT_INSTRUCTION_EXCEPTION || type > UT_TRAP_INSTRUCTION_31)
                return -EINVAL;
        if (new_p == (utrap_handler_t)(long)UTH_NOCHANGE) {
                if (old_p) {
                        if (!current_thread_info()->utraps) {
                                if (put_user(NULL, old_p))
                                        return -EFAULT;
                        } else {
                                if (put_user((utrap_handler_t)(current_thread_info()->utraps[type]), old_p))
                                        return -EFAULT;
                        }
                }
                if (old_d) {
                        if (put_user(NULL, old_d))
                                return -EFAULT;
                }
                return 0;
        }
        if (!current_thread_info()->utraps) {
                current_thread_info()->utraps =
                        kzalloc((UT_TRAP_INSTRUCTION_31+1)*sizeof(long), GFP_KERNEL);
                if (!current_thread_info()->utraps)
                        return -ENOMEM;
                current_thread_info()->utraps[0] = 1;
        } else {
                if ((utrap_handler_t)current_thread_info()->utraps[type] != new_p &&
                    current_thread_info()->utraps[0] > 1) {
                        unsigned long *p = current_thread_info()->utraps;

                        current_thread_info()->utraps =
                                kmalloc((UT_TRAP_INSTRUCTION_31+1)*sizeof(long),
                                        GFP_KERNEL);
                        if (!current_thread_info()->utraps) {
                                current_thread_info()->utraps = p;
                                return -ENOMEM;
                        }
                        p[0]--;
                        current_thread_info()->utraps[0] = 1;
                        memcpy(current_thread_info()->utraps+1, p+1,
                               UT_TRAP_INSTRUCTION_31*sizeof(long));
                }
        }
        if (old_p) {
                if (put_user((utrap_handler_t)(current_thread_info()->utraps[type]), old_p))
                        return -EFAULT;
        }
        if (old_d) {
                if (put_user(NULL, old_d))
                        return -EFAULT;
        }
        current_thread_info()->utraps[type] = (long)new_p;

        return 0;
}

asmlinkage long sparc_memory_ordering(unsigned long model,
                                      struct pt_regs *regs)
{
        if (model >= 3)
                return -EINVAL;
        regs->tstate = (regs->tstate & ~TSTATE_MM) | (model << 14);
        return 0;
}

SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act,
                struct sigaction __user *, oact, void __user *, restorer,
                size_t, sigsetsize)
{
        struct k_sigaction new_ka, old_ka;
        int ret;

        /* XXX: Don't preclude handling different sized sigset_t's.  */
        if (sigsetsize != sizeof(sigset_t))
                return -EINVAL;

        if (act) {
                new_ka.ka_restorer = restorer;
                if (copy_from_user(&new_ka.sa, act, sizeof(*act)))
                        return -EFAULT;
        }

        ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);

        if (!ret && oact) {
                if (copy_to_user(oact, &old_ka.sa, sizeof(*oact)))
                        return -EFAULT;
        }

        return ret;
}

/* Invoked by rtrap code to update performance counters in
 * user space.
 */
asmlinkage void update_perfctrs(void)
{
        unsigned long pic, tmp;

        read_pic(pic);
        tmp = (current_thread_info()->kernel_cntd0 += (unsigned int)pic);
        __put_user(tmp, current_thread_info()->user_cntd0);
        tmp = (current_thread_info()->kernel_cntd1 += (pic >> 32));
        __put_user(tmp, current_thread_info()->user_cntd1);
        reset_pic();
}

SYSCALL_DEFINE4(perfctr, int, opcode, unsigned long, arg0,
                unsigned long, arg1, unsigned long, arg2)
{
        int err = 0;

        switch(opcode) {
        case PERFCTR_ON:
                current_thread_info()->pcr_reg = arg2;
                current_thread_info()->user_cntd0 = (u64 __user *) arg0;
                current_thread_info()->user_cntd1 = (u64 __user *) arg1;
                current_thread_info()->kernel_cntd0 =
                        current_thread_info()->kernel_cntd1 = 0;
                write_pcr(arg2);
                reset_pic();
                set_thread_flag(TIF_PERFCTR);
                break;

        case PERFCTR_OFF:
                err = -EINVAL;
                if (test_thread_flag(TIF_PERFCTR)) {
                        current_thread_info()->user_cntd0 =
                                current_thread_info()->user_cntd1 = NULL;
                        current_thread_info()->pcr_reg = 0;
                        write_pcr(0);
                        clear_thread_flag(TIF_PERFCTR);
                        err = 0;
                }
                break;

        case PERFCTR_READ: {
                unsigned long pic, tmp;

                if (!test_thread_flag(TIF_PERFCTR)) {
                        err = -EINVAL;
                        break;
                }
                read_pic(pic);
                tmp = (current_thread_info()->kernel_cntd0 += (unsigned int)pic);
                err |= __put_user(tmp, current_thread_info()->user_cntd0);
                tmp = (current_thread_info()->kernel_cntd1 += (pic >> 32));
                err |= __put_user(tmp, current_thread_info()->user_cntd1);
                reset_pic();
                break;
        }

        case PERFCTR_CLRPIC:
                if (!test_thread_flag(TIF_PERFCTR)) {
                        err = -EINVAL;
                        break;
                }
                current_thread_info()->kernel_cntd0 =
                        current_thread_info()->kernel_cntd1 = 0;
                reset_pic();
                break;

        case PERFCTR_SETPCR: {
                u64 __user *user_pcr = (u64 __user *)arg0;

                if (!test_thread_flag(TIF_PERFCTR)) {
                        err = -EINVAL;
                        break;
                }
                err |= __get_user(current_thread_info()->pcr_reg, user_pcr);
                write_pcr(current_thread_info()->pcr_reg);
                current_thread_info()->kernel_cntd0 =
                        current_thread_info()->kernel_cntd1 = 0;
                reset_pic();
                break;
        }

        case PERFCTR_GETPCR: {
                u64 __user *user_pcr = (u64 __user *)arg0;

                if (!test_thread_flag(TIF_PERFCTR)) {
                        err = -EINVAL;
                        break;
                }
                err |= __put_user(current_thread_info()->pcr_reg, user_pcr);
                break;
        }

        default:
                err = -EINVAL;
                break;
        };
        return err;
}

/*
 * Do a system call from kernel instead of calling sys_execve so we
 * end up with proper pt_regs.
 */
int kernel_execve(const char *filename, char *const argv[], char *const envp[])
{
        long __res;
        register long __g1 __asm__ ("g1") = __NR_execve;
        register long __o0 __asm__ ("o0") = (long)(filename);
        register long __o1 __asm__ ("o1") = (long)(argv);
        register long __o2 __asm__ ("o2") = (long)(envp);
        asm volatile ("t 0x6d\n\t"
                      "sub %%g0, %%o0, %0\n\t"
                      "movcc %%xcc, %%o0, %0\n\t"
                      : "=r" (__res), "=&r" (__o0)
                      : "1" (__o0), "r" (__o1), "r" (__o2), "r" (__g1)
                      : "cc");
        return __res;
}