// SPDX-License-Identifier: GPL-2.0
/* linux/arch/sparc/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/signal.h>
#include <linux/sched/mm.h>
#include <linux/sched/debug.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/stat.h>
#include <linux/syscalls.h>
#include <linux/mman.h>
#include <linux/utsname.h>
#include <linux/smp.h>
#include <linux/ipc.h>
#include <linux/hugetlb.h>

#include <linux/uaccess.h>
#include <asm/unistd.h>

#include "systbls.h"

/* #define DEBUG_UNIMP_SYSCALL */

/* XXX Make this per-binary type, this way we can detect the type of
 * XXX a binary.  Every Sparc executable calls this very early on.
 */
SYSCALL_DEFINE0(getpagesize)
{
        return PAGE_SIZE; /* Possibly older binaries want 8192 on sun4's? */
}

unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags, vm_flags_t vm_flags)
{
        struct vm_unmapped_area_info info = {};
        bool file_hugepage = false;

        if (filp && is_file_hugepages(filp))
                file_hugepage = true;

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

        /* See asm-sparc/uaccess.h */
        if (len > TASK_SIZE - PAGE_SIZE)
                return -ENOMEM;
        if (!addr)
                addr = TASK_UNMAPPED_BASE;

        info.length = len;
        info.low_limit = addr;
        info.high_limit = TASK_SIZE;
        if (!file_hugepage) {
                info.align_mask = (flags & MAP_SHARED) ?
                        (PAGE_MASK & (SHMLBA - 1)) : 0;
                info.align_offset = pgoff << PAGE_SHIFT;
        } else {
                info.align_mask = huge_page_mask_align(filp);
        }
        return vm_unmapped_area(&info);
}

/*
 * sys_pipe() is the normal C calling standard for creating
 * a pipe. It's not the way unix traditionally does this, though.
 */
SYSCALL_DEFINE0(sparc_pipe)
{
        int fd[2];
        int error;

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

int sparc_mmap_check(unsigned long addr, unsigned long len)
{
        /* See asm-sparc/uaccess.h */
        if (len > TASK_SIZE - PAGE_SIZE || addr + len > TASK_SIZE - PAGE_SIZE)
                return -EINVAL;

        return 0;
}

/* Linux version of mmap */

SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
        unsigned long, prot, unsigned long, flags, unsigned long, fd,
        unsigned long, pgoff)
{
        /* Make sure the shift for mmap2 is constant (12), no matter what PAGE_SIZE
           we have. */
        return ksys_mmap_pgoff(addr, len, prot, flags, fd,
                               pgoff >> (PAGE_SHIFT - 12));
}

SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
        unsigned long, prot, unsigned long, flags, unsigned long, fd,
        unsigned long, off)
{
        /* no alignment check? */
        return ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
}

SYSCALL_DEFINE5(sparc_remap_file_pages, unsigned long, start, unsigned long, size,
                           unsigned long, prot, unsigned long, pgoff,
                           unsigned long, flags)
{
        /* This works on an existing mmap so we don't need to validate
         * the range as that was done at the original mmap call.
         */
        return sys_remap_file_pages(start, size, prot,
                                    (pgoff >> (PAGE_SHIFT - 12)), flags);
}

SYSCALL_DEFINE0(nis_syscall)
{
        static int count = 0;
        struct pt_regs *regs = current_pt_regs();

        if (count++ > 5)
                return -ENOSYS;
        printk ("%s[%d]: Unimplemented SPARC system call %d\n",
                current->comm, task_pid_nr(current), (int)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)
{

#ifdef DEBUG_SPARC_BREAKPOINT
        printk ("TRAP: Entering kernel PC=%x, nPC=%x\n", regs->pc, regs->npc);
#endif
        force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc);

#ifdef DEBUG_SPARC_BREAKPOINT
        printk ("TRAP: Returning to space: PC=%x nPC=%x\n", regs->pc, regs->npc);
#endif
}

SYSCALL_DEFINE3(sparc_sigaction, int, sig,
                struct old_sigaction __user *,act,
                struct old_sigaction __user *,oact)
{
        WARN_ON_ONCE(sig >= 0);
        return sys_sigaction(-sig, act, oact);
}

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;
}

SYSCALL_DEFINE2(getdomainname, char __user *, name, int, len)
{
        int nlen, err;
        char tmp[__NEW_UTS_LEN + 1];

        if (len < 0)
                return -EINVAL;

        down_read(&uts_sem);

        nlen = strlen(utsname()->domainname) + 1;
        err = -EINVAL;
        if (nlen > len)
                goto out_unlock;
        memcpy(tmp, utsname()->domainname, nlen);

        up_read(&uts_sem);

        if (copy_to_user(name, tmp, nlen))
                return -EFAULT;
        return 0;

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