/*      $NetBSD: rumpcopy.c,v 1.25 2020/07/01 00:42:13 riastradh Exp $  */

/*
 * Copyright (c) 2009 Antti Kantee.  All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: rumpcopy.c,v 1.25 2020/07/01 00:42:13 riastradh Exp $");

#define __UFETCHSTORE_PRIVATE
#define __UCAS_PRIVATE

#include <sys/param.h>
#include <sys/lwp.h>
#include <sys/systm.h>
#include <sys/uio.h>

#include <rump-sys/kern.h>

#include <rump/rumpuser.h>

int
copyin(const void *uaddr, void *kaddr, size_t len)
{
        int error = 0;

        if (len == 0)
                return 0;

        if (__predict_false(uaddr == NULL && len)) {
                return EFAULT;
        }

        if (RUMP_LOCALPROC_P(curproc)) {
                memcpy(kaddr, uaddr, len);
        } else if (len) {
                error = rump_sysproxy_copyin(RUMP_SPVM2CTL(curproc->p_vmspace),
                    uaddr, kaddr, len);
        }

        return error;
}

int
copyout(const void *kaddr, void *uaddr, size_t len)
{
        int error = 0;

        if (len == 0)
                return 0;

        if (__predict_false(uaddr == NULL && len)) {
                return EFAULT;
        }

        if (RUMP_LOCALPROC_P(curproc)) {
                memcpy(uaddr, kaddr, len);
        } else if (len) {
                error = rump_sysproxy_copyout(RUMP_SPVM2CTL(curproc->p_vmspace),
                    kaddr, uaddr, len);
        }
        return error;
}

int
copyinstr(const void *uaddr, void *kaddr, size_t len, size_t *done)
{
        uint8_t *to;
        int rv;

        if (len == 0)
                return 0;

        if (__predict_false(uaddr == NULL)) {
                return EFAULT;
        }

        if (RUMP_LOCALPROC_P(curproc))
                return copystr(uaddr, kaddr, len, done);

        if ((rv = rump_sysproxy_copyinstr(RUMP_SPVM2CTL(curproc->p_vmspace),
            uaddr, kaddr, &len)) != 0)
                return rv;

        /* figure out if we got a terminated string or not */
        to = (uint8_t *)kaddr + (len-1);
        while (to >= (uint8_t *)kaddr) {
                if (*to == 0)
                        goto found;
                to--;
        }
        return ENAMETOOLONG;

 found:
        if (done)
                *done = strlen(kaddr)+1; /* includes termination */

        return 0;
}

int
copyoutstr(const void *kaddr, void *uaddr, size_t len, size_t *done)
{
        size_t slen;
        int error;

        if (len == 0)
                return 0;

        if (__predict_false(uaddr == NULL && len)) {
                return EFAULT;
        }

        if (RUMP_LOCALPROC_P(curproc))
                return copystr(kaddr, uaddr, len, done);

        slen = strlen(kaddr)+1;
        if (slen > len)
                return ENAMETOOLONG;

        error = rump_sysproxy_copyoutstr(RUMP_SPVM2CTL(curproc->p_vmspace),
            kaddr, uaddr, &slen);
        if (done)
                *done = slen;

        return error;
}

int
kcopy(const void *src, void *dst, size_t len)
{

        if (len == 0)
                return 0;

        memcpy(dst, src, len);
        return 0;
}

/*
 * Low-level I/O routine.  This is used only when "all else fails",
 * i.e. the current thread does not have an appropriate vm context.
 */
int
uvm_io(struct vm_map *vm, struct uio *uio, int flag)
{
        int error = 0;

        /* loop over iovecs one-by-one and copyout */
        for (; uio->uio_resid && uio->uio_iovcnt;
            uio->uio_iovcnt--, uio->uio_iov++) {
                struct iovec *iov = uio->uio_iov;
                size_t curlen = MIN(uio->uio_resid, iov->iov_len);

                if (__predict_false(curlen == 0))
                        continue;

                if (uio->uio_rw == UIO_READ) {
                        error = rump_sysproxy_copyin(RUMP_SPVM2CTL(vm),
                            (void *)(vaddr_t)uio->uio_offset, iov->iov_base,
                            curlen);
                } else {
                        error = rump_sysproxy_copyout(RUMP_SPVM2CTL(vm),
                            iov->iov_base, (void *)(vaddr_t)uio->uio_offset,
                            curlen);
                }
                if (error)
                        break;

                iov->iov_base = (uint8_t *)iov->iov_base + curlen;
                iov->iov_len -= curlen;

                uio->uio_resid -= curlen;
                uio->uio_offset += curlen;
        }

        return error;
}

int
_ucas_32(volatile uint32_t *uaddr, uint32_t old, uint32_t new, uint32_t *ret)
{
        uint32_t *uva = ((void *)(uintptr_t)uaddr);
        int error;

        /* XXXXJRT do we need a MP CPU gate? */

        kpreempt_disable();
        error = _ufetch_32(uva, ret);
        if (error == 0 && *ret == old) {
                error = _ustore_32(uva, new);
        }
        kpreempt_enable();

        return error;
}

#ifdef _LP64
int
_ucas_64(volatile uint64_t *uaddr, uint64_t old, uint64_t new, uint64_t *ret)
{
        uint64_t *uva = ((void *)(uintptr_t)uaddr);
        int error;

        /* XXXXJRT do we need a MP CPU gate? */

        kpreempt_disable();
        error = _ufetch_64(uva, ret);
        if (error == 0 && *ret == old) {
                error = _ustore_64(uva, new);
        }
        kpreempt_enable();

        return error;
}
#endif /* _LP64 */

#define UFETCH(sz)                                                      \
int                                                                     \
_ufetch_ ## sz(const uint ## sz ##_t *uaddr, uint ## sz ## _t *valp)    \
{                                                                       \
        int error = 0;                                                  \
                                                                        \
        if (RUMP_LOCALPROC_P(curproc)) {                                \
                *valp = *uaddr;                                         \
        } else {                                                        \
                error = rump_sysproxy_copyin(                           \
                    RUMP_SPVM2CTL(curproc->p_vmspace),                  \
                    uaddr, valp, sizeof(*valp));                        \
        }                                                               \
        return error;                                                   \
}

UFETCH(8)
UFETCH(16)
UFETCH(32)
#ifdef _LP64
UFETCH(64)
#endif

#undef UFETCH

#define USTORE(sz)                                                      \
int                                                                     \
_ustore_ ## sz(uint ## sz ## _t *uaddr, uint ## sz ## _t val)           \
{                                                                       \
        int error = 0;                                                  \
                                                                        \
        if (RUMP_LOCALPROC_P(curproc)) {                                \
                *uaddr = val;                                           \
        } else {                                                        \
                error = rump_sysproxy_copyout(                          \
                    RUMP_SPVM2CTL(curproc->p_vmspace),                  \
                    &val, uaddr, sizeof(val));                          \
        }                                                               \
        return error;                                                   \
}

USTORE(8)
USTORE(16)
USTORE(32)
#ifdef _LP64
USTORE(64)
#endif

#undef USTORE