/*-
 * Copyright (c) 2005-2008 Pawel Jakub Dawidek <pjd@FreeBSD.org>
 * Copyright (c) 2010 Konstantin Belousov <kib@FreeBSD.org>
 * 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 AUTHORS AND CONTRIBUTORS ``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 AUTHORS 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>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/kobj.h>
#include <sys/libkern.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/malloc.h>
#include <sys/rwlock.h>
#include <sys/bus.h>
#include <sys/uio.h>
#include <crypto/aesni/aesni.h>
#include "cryptodev_if.h"

struct aesni_softc {
	int32_t cid;
	uint32_t sid;
	TAILQ_HEAD(aesni_sessions_head, aesni_session) sessions;
	struct rwlock lock;
};

static int aesni_newsession(device_t, uint32_t *sidp, struct cryptoini *cri);
static int aesni_freesession(device_t, uint64_t tid);
static void aesni_freesession_locked(struct aesni_softc *sc,
    struct aesni_session *ses);

MALLOC_DEFINE(M_AESNI, "aesni_data", "AESNI Data");

static void
aesni_identify(driver_t *drv, device_t parent)
{

	/* NB: order 10 is so we get attached after h/w devices */
	if (device_find_child(parent, "aesni", -1) == NULL &&
	    BUS_ADD_CHILD(parent, 10, "aesni", -1) == 0)
		panic("aesni: could not attach");
}

static int
aesni_probe(device_t dev)
{
	char capp[32];

	if ((cpu_feature2 & CPUID2_AESNI) == 0) {
		device_printf(dev, "No AESNI support.\n");
		return (EINVAL);
	}
	strlcpy(capp, "AES-CBC", sizeof(capp));
	device_set_desc_copy(dev, capp);
	return (0);
}

static int
aesni_attach(device_t dev)
{
	struct aesni_softc *sc;

	sc = device_get_softc(dev);
	TAILQ_INIT(&sc->sessions);
	sc->sid = 1;
	sc->cid = crypto_get_driverid(dev, CRYPTOCAP_F_HARDWARE);
	if (sc->cid < 0) {
		device_printf(dev, "Could not get crypto driver id.\n");
		return (ENOMEM);
	}

	rw_init(&sc->lock, "aesni_lock");
	crypto_register(sc->cid, CRYPTO_AES_CBC, 0, 0);
	return (0);
}

static int
aesni_detach(device_t dev)
{
	struct aesni_softc *sc;
	struct aesni_session *ses;

	sc = device_get_softc(dev);
	rw_wlock(&sc->lock);
	TAILQ_FOREACH(ses, &sc->sessions, next) {
		if (ses->used) {
			rw_wunlock(&sc->lock);
			device_printf(dev,
			    "Cannot detach, sessions still active.\n");
			return (EBUSY);
		}
	}
	while ((ses = TAILQ_FIRST(&sc->sessions)) != NULL) {
		TAILQ_REMOVE(&sc->sessions, ses, next);
		free(ses, M_AESNI);
	}
	rw_wunlock(&sc->lock);
	rw_destroy(&sc->lock);
	crypto_unregister_all(sc->cid);
	return (0);
}

static int
aesni_newsession(device_t dev, uint32_t *sidp, struct cryptoini *cri)
{
	struct aesni_softc *sc;
	struct aesni_session *ses;
	struct cryptoini *encini;
	int error;

	if (sidp == NULL || cri == NULL)
		return (EINVAL);

	sc = device_get_softc(dev);
	ses = NULL;
	encini = NULL;
	for (; cri != NULL; cri = cri->cri_next) {
		switch (cri->cri_alg) {
		case CRYPTO_AES_CBC:
			if (encini != NULL)
				return (EINVAL);
			encini = cri;
			break;
		default:
			return (EINVAL);
		}
	}
	if (encini == NULL)
		return (EINVAL);

	rw_wlock(&sc->lock);
	/*
	 * Free sessions goes first, so if first session is used, we need to
	 * allocate one.
	 */
	ses = TAILQ_FIRST(&sc->sessions);
	if (ses == NULL || ses->used) {
		ses = malloc(sizeof(*ses), M_AESNI, M_NOWAIT | M_ZERO);
		if (ses == NULL) {
			rw_wunlock(&sc->lock);
			return (ENOMEM);
		}
		KASSERT(((uintptr_t)ses) % 0x10 == 0,
		    ("malloc returned unaligned pointer"));
		ses->id = sc->sid++;
	} else {
		TAILQ_REMOVE(&sc->sessions, ses, next);
	}
	ses->used = 1;
	TAILQ_INSERT_TAIL(&sc->sessions, ses, next);
	rw_wunlock(&sc->lock);

	error = aesni_cipher_setup(ses, encini);
	if (error != 0) {
		rw_wlock(&sc->lock);
		aesni_freesession_locked(sc, ses);
		rw_wunlock(&sc->lock);
		return (error);
	}

	*sidp = ses->id;
	return (0);
}

static void
aesni_freesession_locked(struct aesni_softc *sc, struct aesni_session *ses)
{
	uint32_t sid;

	sid = ses->id;
	TAILQ_REMOVE(&sc->sessions, ses, next);
	bzero(ses, sizeof(*ses));
	ses->id = sid;
	TAILQ_INSERT_HEAD(&sc->sessions, ses, next);
}

static int
aesni_freesession(device_t dev, uint64_t tid)
{
	struct aesni_softc *sc;
	struct aesni_session *ses;
	uint32_t sid;

	sc = device_get_softc(dev);
	sid = ((uint32_t)tid) & 0xffffffff;
	rw_wlock(&sc->lock);
	TAILQ_FOREACH_REVERSE(ses, &sc->sessions, aesni_sessions_head, next) {
		if (ses->id == sid)
			break;
	}
	if (ses == NULL) {
		rw_wunlock(&sc->lock);
		return (EINVAL);
	}
	aesni_freesession_locked(sc, ses);
	rw_wunlock(&sc->lock);
	return (0);
}

static int
aesni_process(device_t dev, struct cryptop *crp, int hint __unused)
{
	struct aesni_softc *sc = device_get_softc(dev);
	struct aesni_session *ses = NULL;
	struct cryptodesc *crd, *enccrd;
	int error;

	error = 0;
	enccrd = NULL;

	/* Sanity check. */
	if (crp == NULL)
		return (EINVAL);

	if (crp->crp_callback == NULL || crp->crp_desc == NULL) {
		error = EINVAL;
		goto out;
	}

	for (crd = crp->crp_desc; crd != NULL; crd = crd->crd_next) {
		switch (crd->crd_alg) {
		case CRYPTO_AES_CBC:
			if (enccrd != NULL) {
				error = EINVAL;
				goto out;
			}
			enccrd = crd;
			break;
		default:
			return (EINVAL);
		}
	}
	if (enccrd == NULL || (enccrd->crd_len % AES_BLOCK_LEN) != 0) {
		error = EINVAL;
		goto out;
	}

	rw_rlock(&sc->lock);
	TAILQ_FOREACH_REVERSE(ses, &sc->sessions, aesni_sessions_head, next) {
		if (ses->id == (crp->crp_sid & 0xffffffff))
			break;
	}
	rw_runlock(&sc->lock);
	if (ses == NULL) {
		error = EINVAL;
		goto out;
	}

	error = aesni_cipher_process(ses, enccrd, crp);
	if (error != 0)
		goto out;

out:
	crp->crp_etype = error;
	crypto_done(crp);
	return (error);
}

uint8_t *
aesni_cipher_alloc(struct cryptodesc *enccrd, struct cryptop *crp,
    int *allocated)
{
	struct uio *uio;
	struct iovec *iov;
	uint8_t *addr;

	if (crp->crp_flags & CRYPTO_F_IMBUF)
		goto alloc;
	else if (crp->crp_flags & CRYPTO_F_IOV) {
		uio = (struct uio *)crp->crp_buf;
		if (uio->uio_iovcnt != 1)
			goto alloc;
		iov = uio->uio_iov;
		addr = (u_char *)iov->iov_base + enccrd->crd_skip;
	} else
		addr = (u_char *)crp->crp_buf;
	*allocated = 0;
	return (addr);

alloc:
	addr = malloc(enccrd->crd_len, M_AESNI, M_NOWAIT);
	if (addr != NULL) {
		*allocated = 1;
		crypto_copydata(crp->crp_flags, crp->crp_buf, enccrd->crd_skip,
		    enccrd->crd_len, addr);
	} else
		*allocated = 0;
	return (addr);
}

static device_method_t aesni_methods[] = {
	DEVMETHOD(device_identify, aesni_identify),
	DEVMETHOD(device_probe, aesni_probe),
	DEVMETHOD(device_attach, aesni_attach),
	DEVMETHOD(device_detach, aesni_detach),

	DEVMETHOD(cryptodev_newsession, aesni_newsession),
	DEVMETHOD(cryptodev_freesession, aesni_freesession),
	DEVMETHOD(cryptodev_process, aesni_process),

	{0, 0},
};

static driver_t aesni_driver = {
	"aesni",
	aesni_methods,
	sizeof(struct aesni_softc),
};
static devclass_t aesni_devclass;

DRIVER_MODULE(aesni, nexus, aesni_driver, aesni_devclass, 0, 0);
MODULE_VERSION(aesni, 1);
MODULE_DEPEND(aesni, crypto, 1, 1, 1);