/*-
 * Copyright (c) 2005-2008 Pawel Jakub Dawidek <pjd@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/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/lock.h>
#include <sys/rwlock.h>
#include <sys/malloc.h>
#include <sys/libkern.h>
#if defined(__amd64__) || defined(__i386__)
#include <machine/cpufunc.h>
#include <machine/cputypes.h>
#include <machine/fpu.h>
#include <machine/md_var.h>
#include <machine/specialreg.h>
#endif

#include <opencrypto/cryptodev.h>

#include <crypto/via/padlock.h>

#include <sys/kobj.h>
#include <sys/bus.h>
#include "cryptodev_if.h"

/*
 * Technical documentation about the PadLock engine can be found here:
 *
 * http://www.via.com.tw/en/downloads/whitepapers/initiatives/padlock/programming_guide.pdf
 */

struct padlock_softc {
	int32_t		sc_cid;
};

static int padlock_probesession(device_t, const struct crypto_session_params *);
static int padlock_newsession(device_t, crypto_session_t cses,
    const struct crypto_session_params *);
static void padlock_freesession(device_t, crypto_session_t cses);
static void padlock_freesession_one(struct padlock_session *ses);
static int padlock_process(device_t, struct cryptop *crp, int hint __unused);

MALLOC_DEFINE(M_PADLOCK, "padlock_data", "PadLock Data");

static void
padlock_identify(driver_t *drv, device_t parent)
{
	/* NB: order 10 is so we get attached after h/w devices */
	if (device_find_child(parent, "padlock", -1) == NULL &&
	    BUS_ADD_CHILD(parent, 10, "padlock", -1) == 0)
		panic("padlock: could not attach");
}

static int
padlock_probe(device_t dev)
{
#if defined(__amd64__) || defined(__i386__)
	/* If there is no AES support, we has nothing to do here. */
	if (!(via_feature_xcrypt & VIA_HAS_AES)) {
		device_printf(dev, "No ACE support.\n");
		return (EINVAL);
	}
	device_set_descf(dev, "AES-CBC%s",
	    (via_feature_xcrypt & VIA_HAS_SHA) ? ",SHA1,SHA256" : "");
	return (0);
#else
	return (EINVAL);
#endif
}

static int
padlock_attach(device_t dev)
{
	struct padlock_softc *sc = device_get_softc(dev);

	sc->sc_cid = crypto_get_driverid(dev, sizeof(struct padlock_session),
	    CRYPTOCAP_F_SOFTWARE | CRYPTOCAP_F_SYNC |
	    CRYPTOCAP_F_ACCEL_SOFTWARE);
	if (sc->sc_cid < 0) {
		device_printf(dev, "Could not get crypto driver id.\n");
		return (ENOMEM);
	}

	return (0);
}

static int
padlock_detach(device_t dev)
{
	struct padlock_softc *sc = device_get_softc(dev);

	crypto_unregister_all(sc->sc_cid);
	return (0);
}

static int
padlock_probesession(device_t dev, const struct crypto_session_params *csp)
{

	if (csp->csp_flags != 0)
		return (EINVAL);

	/*
	 * We only support HMAC algorithms to be able to work with
	 * ipsec(4), so if we are asked only for authentication without
	 * encryption, don't pretend we can accelerate it.
	 *
	 * XXX: For CPUs with SHA instructions we should probably
	 * permit CSP_MODE_DIGEST so that those can be tested.
	 */
	switch (csp->csp_mode) {
	case CSP_MODE_ETA:
		if (!padlock_hash_check(csp))
			return (EINVAL);
		/* FALLTHROUGH */
	case CSP_MODE_CIPHER:
		switch (csp->csp_cipher_alg) {
		case CRYPTO_AES_CBC:
			if (csp->csp_ivlen != AES_BLOCK_LEN)
				return (EINVAL);
			break;
		default:
			return (EINVAL);
		}
		break;
	default:
		return (EINVAL);
	}

	return (CRYPTODEV_PROBE_ACCEL_SOFTWARE);
}

static int
padlock_newsession(device_t dev, crypto_session_t cses,
    const struct crypto_session_params *csp)
{
	struct padlock_session *ses;
	struct thread *td;
	int error;

	ses = crypto_get_driver_session(cses);

	error = padlock_cipher_setup(ses, csp);
	if (error != 0) {
		padlock_freesession_one(ses);
		return (error);
	}

	if (csp->csp_mode == CSP_MODE_ETA) {
		td = curthread;
		fpu_kern_enter(td, NULL, FPU_KERN_NORMAL | FPU_KERN_NOCTX);
		error = padlock_hash_setup(ses, csp);
		fpu_kern_leave(td, NULL);
		if (error != 0) {
			padlock_freesession_one(ses);
			return (error);
		}
	}

	return (0);
}

static void
padlock_freesession_one(struct padlock_session *ses)
{

	padlock_hash_free(ses);
}

static void
padlock_freesession(device_t dev, crypto_session_t cses)
{
	struct padlock_session *ses;

	ses = crypto_get_driver_session(cses);
	padlock_freesession_one(ses);
}

static int
padlock_process(device_t dev, struct cryptop *crp, int hint __unused)
{
	const struct crypto_session_params *csp;
	struct padlock_session *ses;
	int error;

	if ((crp->crp_payload_length % AES_BLOCK_LEN) != 0) {
		error = EINVAL;
		goto out;
	}

	ses = crypto_get_driver_session(crp->crp_session);
	csp = crypto_get_params(crp->crp_session);

	/* Perform data authentication if requested before decryption. */
	if (csp->csp_mode == CSP_MODE_ETA &&
	    !CRYPTO_OP_IS_ENCRYPT(crp->crp_op)) {
		error = padlock_hash_process(ses, crp, csp);
		if (error != 0)
			goto out;
	}

	error = padlock_cipher_process(ses, crp, csp);
	if (error != 0)
		goto out;

	/* Perform data authentication if requested after encryption. */
	if (csp->csp_mode == CSP_MODE_ETA &&
	    CRYPTO_OP_IS_ENCRYPT(crp->crp_op)) {
		error = padlock_hash_process(ses, crp, csp);
		if (error != 0)
			goto out;
	}

out:
#if 0
	/*
	 * This code is not necessary, because contexts will be freed on next
	 * padlock_setup_mackey() call or at padlock_freesession() call.
	 */
	if (ses != NULL && maccrd != NULL &&
	    (maccrd->crd_flags & CRD_F_KEY_EXPLICIT) != 0) {
		padlock_free_ctx(ses->ses_axf, ses->ses_ictx);
		padlock_free_ctx(ses->ses_axf, ses->ses_octx);
	}
#endif
	crp->crp_etype = error;
	crypto_done(crp);
	return (0);
}

static device_method_t padlock_methods[] = {
	DEVMETHOD(device_identify,	padlock_identify),
	DEVMETHOD(device_probe,		padlock_probe),
	DEVMETHOD(device_attach,	padlock_attach),
	DEVMETHOD(device_detach,	padlock_detach),

	DEVMETHOD(cryptodev_probesession, padlock_probesession),
	DEVMETHOD(cryptodev_newsession,	padlock_newsession),
	DEVMETHOD(cryptodev_freesession,padlock_freesession),
	DEVMETHOD(cryptodev_process,	padlock_process),

	{0, 0},
};

static driver_t padlock_driver = {
	"padlock",
	padlock_methods,
	sizeof(struct padlock_softc),
};

/* XXX where to attach */
DRIVER_MODULE(padlock, nexus, padlock_driver, 0, 0);
MODULE_VERSION(padlock, 1);
MODULE_DEPEND(padlock, crypto, 1, 1, 1);