rename target/linux/generic-2.6 to generic
[15.05/openwrt.git] / target / linux / generic / files / crypto / ocf / crypto.c
diff --git a/target/linux/generic/files/crypto/ocf/crypto.c b/target/linux/generic/files/crypto/ocf/crypto.c
new file mode 100644 (file)
index 0000000..9735f0c
--- /dev/null
@@ -0,0 +1,1784 @@
+/*-
+ * Linux port done by David McCullough <david_mccullough@mcafee.com>
+ * Copyright (C) 2006-2010 David McCullough
+ * Copyright (C) 2004-2005 Intel Corporation.
+ * The license and original author are listed below.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * Copyright (c) 2002-2006 Sam Leffler.  All rights reserved.
+ *
+ * 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 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.
+ */
+
+#if 0
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD: src/sys/opencrypto/crypto.c,v 1.27 2007/03/21 03:42:51 sam Exp $");
+#endif
+
+/*
+ * Cryptographic Subsystem.
+ *
+ * This code is derived from the Openbsd Cryptographic Framework (OCF)
+ * that has the copyright shown below.  Very little of the original
+ * code remains.
+ */
+/*-
+ * The author of this code is Angelos D. Keromytis (angelos@cis.upenn.edu)
+ *
+ * This code was written by Angelos D. Keromytis in Athens, Greece, in
+ * February 2000. Network Security Technologies Inc. (NSTI) kindly
+ * supported the development of this code.
+ *
+ * Copyright (c) 2000, 2001 Angelos D. Keromytis
+ *
+ * Permission to use, copy, and modify this software with or without fee
+ * is hereby granted, provided that this entire notice is included in
+ * all source code copies of any software which is or includes a copy or
+ * modification of this software.
+ *
+ * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
+ * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
+ * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
+ * PURPOSE.
+ *
+__FBSDID("$FreeBSD: src/sys/opencrypto/crypto.c,v 1.16 2005/01/07 02:29:16 imp Exp $");
+ */
+
+
+#ifndef AUTOCONF_INCLUDED
+#include <linux/config.h>
+#endif
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/version.h>
+#include <cryptodev.h>
+
+/*
+ * keep track of whether or not we have been initialised, a big
+ * issue if we are linked into the kernel and a driver gets started before
+ * us
+ */
+static int crypto_initted = 0;
+
+/*
+ * Crypto drivers register themselves by allocating a slot in the
+ * crypto_drivers table with crypto_get_driverid() and then registering
+ * each algorithm they support with crypto_register() and crypto_kregister().
+ */
+
+/*
+ * lock on driver table
+ * we track its state as spin_is_locked does not do anything on non-SMP boxes
+ */
+static spinlock_t      crypto_drivers_lock;
+static int                     crypto_drivers_locked;          /* for non-SMP boxes */
+
+#define        CRYPTO_DRIVER_LOCK() \
+                       ({ \
+                               spin_lock_irqsave(&crypto_drivers_lock, d_flags); \
+                               crypto_drivers_locked = 1; \
+                               dprintk("%s,%d: DRIVER_LOCK()\n", __FILE__, __LINE__); \
+                        })
+#define        CRYPTO_DRIVER_UNLOCK() \
+                       ({ \
+                               dprintk("%s,%d: DRIVER_UNLOCK()\n", __FILE__, __LINE__); \
+                               crypto_drivers_locked = 0; \
+                               spin_unlock_irqrestore(&crypto_drivers_lock, d_flags); \
+                        })
+#define        CRYPTO_DRIVER_ASSERT() \
+                       ({ \
+                               if (!crypto_drivers_locked) { \
+                                       dprintk("%s,%d: DRIVER_ASSERT!\n", __FILE__, __LINE__); \
+                               } \
+                        })
+
+/*
+ * Crypto device/driver capabilities structure.
+ *
+ * Synchronization:
+ * (d) - protected by CRYPTO_DRIVER_LOCK()
+ * (q) - protected by CRYPTO_Q_LOCK()
+ * Not tagged fields are read-only.
+ */
+struct cryptocap {
+       device_t        cc_dev;                 /* (d) device/driver */
+       u_int32_t       cc_sessions;            /* (d) # of sessions */
+       u_int32_t       cc_koperations;         /* (d) # os asym operations */
+       /*
+        * Largest possible operator length (in bits) for each type of
+        * encryption algorithm. XXX not used
+        */
+       u_int16_t       cc_max_op_len[CRYPTO_ALGORITHM_MAX + 1];
+       u_int8_t        cc_alg[CRYPTO_ALGORITHM_MAX + 1];
+       u_int8_t        cc_kalg[CRK_ALGORITHM_MAX + 1];
+
+       int             cc_flags;               /* (d) flags */
+#define CRYPTOCAP_F_CLEANUP    0x80000000      /* needs resource cleanup */
+       int             cc_qblocked;            /* (q) symmetric q blocked */
+       int             cc_kqblocked;           /* (q) asymmetric q blocked */
+
+       int             cc_unqblocked;          /* (q) symmetric q blocked */
+       int             cc_unkqblocked;         /* (q) asymmetric q blocked */
+};
+static struct cryptocap *crypto_drivers = NULL;
+static int crypto_drivers_num = 0;
+
+/*
+ * There are two queues for crypto requests; one for symmetric (e.g.
+ * cipher) operations and one for asymmetric (e.g. MOD)operations.
+ * A single mutex is used to lock access to both queues.  We could
+ * have one per-queue but having one simplifies handling of block/unblock
+ * operations.
+ */
+static int crp_sleep = 0;
+static LIST_HEAD(crp_q);               /* request queues */
+static LIST_HEAD(crp_kq);
+
+static spinlock_t crypto_q_lock;
+
+int crypto_all_qblocked = 0;  /* protect with Q_LOCK */
+module_param(crypto_all_qblocked, int, 0444);
+MODULE_PARM_DESC(crypto_all_qblocked, "Are all crypto queues blocked");
+
+int crypto_all_kqblocked = 0; /* protect with Q_LOCK */
+module_param(crypto_all_kqblocked, int, 0444);
+MODULE_PARM_DESC(crypto_all_kqblocked, "Are all asym crypto queues blocked");
+
+#define        CRYPTO_Q_LOCK() \
+                       ({ \
+                               spin_lock_irqsave(&crypto_q_lock, q_flags); \
+                               dprintk("%s,%d: Q_LOCK()\n", __FILE__, __LINE__); \
+                        })
+#define        CRYPTO_Q_UNLOCK() \
+                       ({ \
+                               dprintk("%s,%d: Q_UNLOCK()\n", __FILE__, __LINE__); \
+                               spin_unlock_irqrestore(&crypto_q_lock, q_flags); \
+                        })
+
+/*
+ * There are two queues for processing completed crypto requests; one
+ * for the symmetric and one for the asymmetric ops.  We only need one
+ * but have two to avoid type futzing (cryptop vs. cryptkop).  A single
+ * mutex is used to lock access to both queues.  Note that this lock
+ * must be separate from the lock on request queues to insure driver
+ * callbacks don't generate lock order reversals.
+ */
+static LIST_HEAD(crp_ret_q);           /* callback queues */
+static LIST_HEAD(crp_ret_kq);
+
+static spinlock_t crypto_ret_q_lock;
+#define        CRYPTO_RETQ_LOCK() \
+                       ({ \
+                               spin_lock_irqsave(&crypto_ret_q_lock, r_flags); \
+                               dprintk("%s,%d: RETQ_LOCK\n", __FILE__, __LINE__); \
+                        })
+#define        CRYPTO_RETQ_UNLOCK() \
+                       ({ \
+                               dprintk("%s,%d: RETQ_UNLOCK\n", __FILE__, __LINE__); \
+                               spin_unlock_irqrestore(&crypto_ret_q_lock, r_flags); \
+                        })
+#define        CRYPTO_RETQ_EMPTY()     (list_empty(&crp_ret_q) && list_empty(&crp_ret_kq))
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20)
+static kmem_cache_t *cryptop_zone;
+static kmem_cache_t *cryptodesc_zone;
+#else
+static struct kmem_cache *cryptop_zone;
+static struct kmem_cache *cryptodesc_zone;
+#endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27)
+#include <linux/sched.h>
+#define        kill_proc(p,s,v)        send_sig(s,find_task_by_vpid(p),0)
+#endif
+
+#define debug crypto_debug
+int crypto_debug = 0;
+module_param(crypto_debug, int, 0644);
+MODULE_PARM_DESC(crypto_debug, "Enable debug");
+EXPORT_SYMBOL(crypto_debug);
+
+/*
+ * Maximum number of outstanding crypto requests before we start
+ * failing requests.  We need this to prevent DOS when too many
+ * requests are arriving for us to keep up.  Otherwise we will
+ * run the system out of memory.  Since crypto is slow,  we are
+ * usually the bottleneck that needs to say, enough is enough.
+ *
+ * We cannot print errors when this condition occurs,  we are already too
+ * slow,  printing anything will just kill us
+ */
+
+static int crypto_q_cnt = 0;
+module_param(crypto_q_cnt, int, 0444);
+MODULE_PARM_DESC(crypto_q_cnt,
+               "Current number of outstanding crypto requests");
+
+static int crypto_q_max = 1000;
+module_param(crypto_q_max, int, 0644);
+MODULE_PARM_DESC(crypto_q_max,
+               "Maximum number of outstanding crypto requests");
+
+#define bootverbose crypto_verbose
+static int crypto_verbose = 0;
+module_param(crypto_verbose, int, 0644);
+MODULE_PARM_DESC(crypto_verbose,
+               "Enable verbose crypto startup");
+
+int    crypto_usercrypto = 1;  /* userland may do crypto reqs */
+module_param(crypto_usercrypto, int, 0644);
+MODULE_PARM_DESC(crypto_usercrypto,
+          "Enable/disable user-mode access to crypto support");
+
+int    crypto_userasymcrypto = 1;      /* userland may do asym crypto reqs */
+module_param(crypto_userasymcrypto, int, 0644);
+MODULE_PARM_DESC(crypto_userasymcrypto,
+          "Enable/disable user-mode access to asymmetric crypto support");
+
+int    crypto_devallowsoft = 0;        /* only use hardware crypto */
+module_param(crypto_devallowsoft, int, 0644);
+MODULE_PARM_DESC(crypto_devallowsoft,
+          "Enable/disable use of software crypto support");
+
+/*
+ * This parameter controls the maximum number of crypto operations to 
+ * do consecutively in the crypto kernel thread before scheduling to allow 
+ * other processes to run. Without it, it is possible to get into a 
+ * situation where the crypto thread never allows any other processes to run.
+ * Default to 1000 which should be less than one second.
+ */
+static int crypto_max_loopcount = 1000;
+module_param(crypto_max_loopcount, int, 0644);
+MODULE_PARM_DESC(crypto_max_loopcount,
+          "Maximum number of crypto ops to do before yielding to other processes");
+
+static pid_t   cryptoproc = (pid_t) -1;
+static struct  completion cryptoproc_exited;
+static DECLARE_WAIT_QUEUE_HEAD(cryptoproc_wait);
+static pid_t   cryptoretproc = (pid_t) -1;
+static struct  completion cryptoretproc_exited;
+static DECLARE_WAIT_QUEUE_HEAD(cryptoretproc_wait);
+
+static int crypto_proc(void *arg);
+static int crypto_ret_proc(void *arg);
+static int crypto_invoke(struct cryptocap *cap, struct cryptop *crp, int hint);
+static int crypto_kinvoke(struct cryptkop *krp, int flags);
+static void crypto_exit(void);
+static  int crypto_init(void);
+
+static struct cryptostats cryptostats;
+
+static struct cryptocap *
+crypto_checkdriver(u_int32_t hid)
+{
+       if (crypto_drivers == NULL)
+               return NULL;
+       return (hid >= crypto_drivers_num ? NULL : &crypto_drivers[hid]);
+}
+
+/*
+ * Compare a driver's list of supported algorithms against another
+ * list; return non-zero if all algorithms are supported.
+ */
+static int
+driver_suitable(const struct cryptocap *cap, const struct cryptoini *cri)
+{
+       const struct cryptoini *cr;
+
+       /* See if all the algorithms are supported. */
+       for (cr = cri; cr; cr = cr->cri_next)
+               if (cap->cc_alg[cr->cri_alg] == 0)
+                       return 0;
+       return 1;
+}
+
+/*
+ * Select a driver for a new session that supports the specified
+ * algorithms and, optionally, is constrained according to the flags.
+ * The algorithm we use here is pretty stupid; just use the
+ * first driver that supports all the algorithms we need. If there
+ * are multiple drivers we choose the driver with the fewest active
+ * sessions.  We prefer hardware-backed drivers to software ones.
+ *
+ * XXX We need more smarts here (in real life too, but that's
+ * XXX another story altogether).
+ */
+static struct cryptocap *
+crypto_select_driver(const struct cryptoini *cri, int flags)
+{
+       struct cryptocap *cap, *best;
+       int match, hid;
+
+       CRYPTO_DRIVER_ASSERT();
+
+       /*
+        * Look first for hardware crypto devices if permitted.
+        */
+       if (flags & CRYPTOCAP_F_HARDWARE)
+               match = CRYPTOCAP_F_HARDWARE;
+       else
+               match = CRYPTOCAP_F_SOFTWARE;
+       best = NULL;
+again:
+       for (hid = 0; hid < crypto_drivers_num; hid++) {
+               cap = &crypto_drivers[hid];
+               /*
+                * If it's not initialized, is in the process of
+                * going away, or is not appropriate (hardware
+                * or software based on match), then skip.
+                */
+               if (cap->cc_dev == NULL ||
+                   (cap->cc_flags & CRYPTOCAP_F_CLEANUP) ||
+                   (cap->cc_flags & match) == 0)
+                       continue;
+
+               /* verify all the algorithms are supported. */
+               if (driver_suitable(cap, cri)) {
+                       if (best == NULL ||
+                           cap->cc_sessions < best->cc_sessions)
+                               best = cap;
+               }
+       }
+       if (best != NULL)
+               return best;
+       if (match == CRYPTOCAP_F_HARDWARE && (flags & CRYPTOCAP_F_SOFTWARE)) {
+               /* sort of an Algol 68-style for loop */
+               match = CRYPTOCAP_F_SOFTWARE;
+               goto again;
+       }
+       return best;
+}
+
+/*
+ * Create a new session.  The crid argument specifies a crypto
+ * driver to use or constraints on a driver to select (hardware
+ * only, software only, either).  Whatever driver is selected
+ * must be capable of the requested crypto algorithms.
+ */
+int
+crypto_newsession(u_int64_t *sid, struct cryptoini *cri, int crid)
+{
+       struct cryptocap *cap;
+       u_int32_t hid, lid;
+       int err;
+       unsigned long d_flags;
+
+       CRYPTO_DRIVER_LOCK();
+       if ((crid & (CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE)) == 0) {
+               /*
+                * Use specified driver; verify it is capable.
+                */
+               cap = crypto_checkdriver(crid);
+               if (cap != NULL && !driver_suitable(cap, cri))
+                       cap = NULL;
+       } else {
+               /*
+                * No requested driver; select based on crid flags.
+                */
+               cap = crypto_select_driver(cri, crid);
+               /*
+                * if NULL then can't do everything in one session.
+                * XXX Fix this. We need to inject a "virtual" session
+                * XXX layer right about here.
+                */
+       }
+       if (cap != NULL) {
+               /* Call the driver initialization routine. */
+               hid = cap - crypto_drivers;
+               lid = hid;              /* Pass the driver ID. */
+               cap->cc_sessions++;
+               CRYPTO_DRIVER_UNLOCK();
+               err = CRYPTODEV_NEWSESSION(cap->cc_dev, &lid, cri);
+               CRYPTO_DRIVER_LOCK();
+               if (err == 0) {
+                       (*sid) = (cap->cc_flags & 0xff000000)
+                              | (hid & 0x00ffffff);
+                       (*sid) <<= 32;
+                       (*sid) |= (lid & 0xffffffff);
+               } else
+                       cap->cc_sessions--;
+       } else
+               err = EINVAL;
+       CRYPTO_DRIVER_UNLOCK();
+       return err;
+}
+
+static void
+crypto_remove(struct cryptocap *cap)
+{
+       CRYPTO_DRIVER_ASSERT();
+       if (cap->cc_sessions == 0 && cap->cc_koperations == 0)
+               bzero(cap, sizeof(*cap));
+}
+
+/*
+ * Delete an existing session (or a reserved session on an unregistered
+ * driver).
+ */
+int
+crypto_freesession(u_int64_t sid)
+{
+       struct cryptocap *cap;
+       u_int32_t hid;
+       int err = 0;
+       unsigned long d_flags;
+
+       dprintk("%s()\n", __FUNCTION__);
+       CRYPTO_DRIVER_LOCK();
+
+       if (crypto_drivers == NULL) {
+               err = EINVAL;
+               goto done;
+       }
+
+       /* Determine two IDs. */
+       hid = CRYPTO_SESID2HID(sid);
+
+       if (hid >= crypto_drivers_num) {
+               dprintk("%s - INVALID DRIVER NUM %d\n", __FUNCTION__, hid);
+               err = ENOENT;
+               goto done;
+       }
+       cap = &crypto_drivers[hid];
+
+       if (cap->cc_dev) {
+               CRYPTO_DRIVER_UNLOCK();
+               /* Call the driver cleanup routine, if available, unlocked. */
+               err = CRYPTODEV_FREESESSION(cap->cc_dev, sid);
+               CRYPTO_DRIVER_LOCK();
+       }
+
+       if (cap->cc_sessions)
+               cap->cc_sessions--;
+
+       if (cap->cc_flags & CRYPTOCAP_F_CLEANUP)
+               crypto_remove(cap);
+
+done:
+       CRYPTO_DRIVER_UNLOCK();
+       return err;
+}
+
+/*
+ * Return an unused driver id.  Used by drivers prior to registering
+ * support for the algorithms they handle.
+ */
+int32_t
+crypto_get_driverid(device_t dev, int flags)
+{
+       struct cryptocap *newdrv;
+       int i;
+       unsigned long d_flags;
+
+       if ((flags & (CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE)) == 0) {
+               printf("%s: no flags specified when registering driver\n",
+                   device_get_nameunit(dev));
+               return -1;
+       }
+
+       CRYPTO_DRIVER_LOCK();
+
+       for (i = 0; i < crypto_drivers_num; i++) {
+               if (crypto_drivers[i].cc_dev == NULL &&
+                   (crypto_drivers[i].cc_flags & CRYPTOCAP_F_CLEANUP) == 0) {
+                       break;
+               }
+       }
+
+       /* Out of entries, allocate some more. */
+       if (i == crypto_drivers_num) {
+               /* Be careful about wrap-around. */
+               if (2 * crypto_drivers_num <= crypto_drivers_num) {
+                       CRYPTO_DRIVER_UNLOCK();
+                       printk("crypto: driver count wraparound!\n");
+                       return -1;
+               }
+
+               newdrv = kmalloc(2 * crypto_drivers_num * sizeof(struct cryptocap),
+                               GFP_KERNEL);
+               if (newdrv == NULL) {
+                       CRYPTO_DRIVER_UNLOCK();
+                       printk("crypto: no space to expand driver table!\n");
+                       return -1;
+               }
+
+               memcpy(newdrv, crypto_drivers,
+                               crypto_drivers_num * sizeof(struct cryptocap));
+               memset(&newdrv[crypto_drivers_num], 0,
+                               crypto_drivers_num * sizeof(struct cryptocap));
+
+               crypto_drivers_num *= 2;
+
+               kfree(crypto_drivers);
+               crypto_drivers = newdrv;
+       }
+
+       /* NB: state is zero'd on free */
+       crypto_drivers[i].cc_sessions = 1;      /* Mark */
+       crypto_drivers[i].cc_dev = dev;
+       crypto_drivers[i].cc_flags = flags;
+       if (bootverbose)
+               printf("crypto: assign %s driver id %u, flags %u\n",
+                   device_get_nameunit(dev), i, flags);
+
+       CRYPTO_DRIVER_UNLOCK();
+
+       return i;
+}
+
+/*
+ * Lookup a driver by name.  We match against the full device
+ * name and unit, and against just the name.  The latter gives
+ * us a simple widlcarding by device name.  On success return the
+ * driver/hardware identifier; otherwise return -1.
+ */
+int
+crypto_find_driver(const char *match)
+{
+       int i, len = strlen(match);
+       unsigned long d_flags;
+
+       CRYPTO_DRIVER_LOCK();
+       for (i = 0; i < crypto_drivers_num; i++) {
+               device_t dev = crypto_drivers[i].cc_dev;
+               if (dev == NULL ||
+                   (crypto_drivers[i].cc_flags & CRYPTOCAP_F_CLEANUP))
+                       continue;
+               if (strncmp(match, device_get_nameunit(dev), len) == 0 ||
+                   strncmp(match, device_get_name(dev), len) == 0)
+                       break;
+       }
+       CRYPTO_DRIVER_UNLOCK();
+       return i < crypto_drivers_num ? i : -1;
+}
+
+/*
+ * Return the device_t for the specified driver or NULL
+ * if the driver identifier is invalid.
+ */
+device_t
+crypto_find_device_byhid(int hid)
+{
+       struct cryptocap *cap = crypto_checkdriver(hid);
+       return cap != NULL ? cap->cc_dev : NULL;
+}
+
+/*
+ * Return the device/driver capabilities.
+ */
+int
+crypto_getcaps(int hid)
+{
+       struct cryptocap *cap = crypto_checkdriver(hid);
+       return cap != NULL ? cap->cc_flags : 0;
+}
+
+/*
+ * Register support for a key-related algorithm.  This routine
+ * is called once for each algorithm supported a driver.
+ */
+int
+crypto_kregister(u_int32_t driverid, int kalg, u_int32_t flags)
+{
+       struct cryptocap *cap;
+       int err;
+       unsigned long d_flags;
+
+       dprintk("%s()\n", __FUNCTION__);
+       CRYPTO_DRIVER_LOCK();
+
+       cap = crypto_checkdriver(driverid);
+       if (cap != NULL &&
+           (CRK_ALGORITM_MIN <= kalg && kalg <= CRK_ALGORITHM_MAX)) {
+               /*
+                * XXX Do some performance testing to determine placing.
+                * XXX We probably need an auxiliary data structure that
+                * XXX describes relative performances.
+                */
+
+               cap->cc_kalg[kalg] = flags | CRYPTO_ALG_FLAG_SUPPORTED;
+               if (bootverbose)
+                       printf("crypto: %s registers key alg %u flags %u\n"
+                               , device_get_nameunit(cap->cc_dev)
+                               , kalg
+                               , flags
+                       );
+               err = 0;
+       } else
+               err = EINVAL;
+
+       CRYPTO_DRIVER_UNLOCK();
+       return err;
+}
+
+/*
+ * Register support for a non-key-related algorithm.  This routine
+ * is called once for each such algorithm supported by a driver.
+ */
+int
+crypto_register(u_int32_t driverid, int alg, u_int16_t maxoplen,
+    u_int32_t flags)
+{
+       struct cryptocap *cap;
+       int err;
+       unsigned long d_flags;
+
+       dprintk("%s(id=0x%x, alg=%d, maxoplen=%d, flags=0x%x)\n", __FUNCTION__,
+                       driverid, alg, maxoplen, flags);
+
+       CRYPTO_DRIVER_LOCK();
+
+       cap = crypto_checkdriver(driverid);
+       /* NB: algorithms are in the range [1..max] */
+       if (cap != NULL &&
+           (CRYPTO_ALGORITHM_MIN <= alg && alg <= CRYPTO_ALGORITHM_MAX)) {
+               /*
+                * XXX Do some performance testing to determine placing.
+                * XXX We probably need an auxiliary data structure that
+                * XXX describes relative performances.
+                */
+
+               cap->cc_alg[alg] = flags | CRYPTO_ALG_FLAG_SUPPORTED;
+               cap->cc_max_op_len[alg] = maxoplen;
+               if (bootverbose)
+                       printf("crypto: %s registers alg %u flags %u maxoplen %u\n"
+                               , device_get_nameunit(cap->cc_dev)
+                               , alg
+                               , flags
+                               , maxoplen
+                       );
+               cap->cc_sessions = 0;           /* Unmark */
+               err = 0;
+       } else
+               err = EINVAL;
+
+       CRYPTO_DRIVER_UNLOCK();
+       return err;
+}
+
+static void
+driver_finis(struct cryptocap *cap)
+{
+       u_int32_t ses, kops;
+
+       CRYPTO_DRIVER_ASSERT();
+
+       ses = cap->cc_sessions;
+       kops = cap->cc_koperations;
+       bzero(cap, sizeof(*cap));
+       if (ses != 0 || kops != 0) {
+               /*
+                * If there are pending sessions,
+                * just mark as invalid.
+                */
+               cap->cc_flags |= CRYPTOCAP_F_CLEANUP;
+               cap->cc_sessions = ses;
+               cap->cc_koperations = kops;
+       }
+}
+
+/*
+ * Unregister a crypto driver. If there are pending sessions using it,
+ * leave enough information around so that subsequent calls using those
+ * sessions will correctly detect the driver has been unregistered and
+ * reroute requests.
+ */
+int
+crypto_unregister(u_int32_t driverid, int alg)
+{
+       struct cryptocap *cap;
+       int i, err;
+       unsigned long d_flags;
+
+       dprintk("%s()\n", __FUNCTION__);
+       CRYPTO_DRIVER_LOCK();
+
+       cap = crypto_checkdriver(driverid);
+       if (cap != NULL &&
+           (CRYPTO_ALGORITHM_MIN <= alg && alg <= CRYPTO_ALGORITHM_MAX) &&
+           cap->cc_alg[alg] != 0) {
+               cap->cc_alg[alg] = 0;
+               cap->cc_max_op_len[alg] = 0;
+
+               /* Was this the last algorithm ? */
+               for (i = 1; i <= CRYPTO_ALGORITHM_MAX; i++)
+                       if (cap->cc_alg[i] != 0)
+                               break;
+
+               if (i == CRYPTO_ALGORITHM_MAX + 1)
+                       driver_finis(cap);
+               err = 0;
+       } else
+               err = EINVAL;
+       CRYPTO_DRIVER_UNLOCK();
+       return err;
+}
+
+/*
+ * Unregister all algorithms associated with a crypto driver.
+ * If there are pending sessions using it, leave enough information
+ * around so that subsequent calls using those sessions will
+ * correctly detect the driver has been unregistered and reroute
+ * requests.
+ */
+int
+crypto_unregister_all(u_int32_t driverid)
+{
+       struct cryptocap *cap;
+       int err;
+       unsigned long d_flags;
+
+       dprintk("%s()\n", __FUNCTION__);
+       CRYPTO_DRIVER_LOCK();
+       cap = crypto_checkdriver(driverid);
+       if (cap != NULL) {
+               driver_finis(cap);
+               err = 0;
+       } else
+               err = EINVAL;
+       CRYPTO_DRIVER_UNLOCK();
+
+       return err;
+}
+
+/*
+ * Clear blockage on a driver.  The what parameter indicates whether
+ * the driver is now ready for cryptop's and/or cryptokop's.
+ */
+int
+crypto_unblock(u_int32_t driverid, int what)
+{
+       struct cryptocap *cap;
+       int err;
+       unsigned long q_flags;
+
+       CRYPTO_Q_LOCK();
+       cap = crypto_checkdriver(driverid);
+       if (cap != NULL) {
+               if (what & CRYPTO_SYMQ) {
+                       cap->cc_qblocked = 0;
+                       cap->cc_unqblocked = 0;
+                       crypto_all_qblocked = 0;
+               }
+               if (what & CRYPTO_ASYMQ) {
+                       cap->cc_kqblocked = 0;
+                       cap->cc_unkqblocked = 0;
+                       crypto_all_kqblocked = 0;
+               }
+               if (crp_sleep)
+                       wake_up_interruptible(&cryptoproc_wait);
+               err = 0;
+       } else
+               err = EINVAL;
+       CRYPTO_Q_UNLOCK(); //DAVIDM should this be a driver lock
+
+       return err;
+}
+
+/*
+ * Add a crypto request to a queue, to be processed by the kernel thread.
+ */
+int
+crypto_dispatch(struct cryptop *crp)
+{
+       struct cryptocap *cap;
+       int result = -1;
+       unsigned long q_flags;
+
+       dprintk("%s()\n", __FUNCTION__);
+
+       cryptostats.cs_ops++;
+
+       CRYPTO_Q_LOCK();
+       if (crypto_q_cnt >= crypto_q_max) {
+               CRYPTO_Q_UNLOCK();
+               cryptostats.cs_drops++;
+               return ENOMEM;
+       }
+       crypto_q_cnt++;
+
+       /* make sure we are starting a fresh run on this crp. */
+       crp->crp_flags &= ~CRYPTO_F_DONE;
+       crp->crp_etype = 0;
+
+       /*
+        * Caller marked the request to be processed immediately; dispatch
+        * it directly to the driver unless the driver is currently blocked.
+        */
+       if ((crp->crp_flags & CRYPTO_F_BATCH) == 0) {
+               int hid = CRYPTO_SESID2HID(crp->crp_sid);
+               cap = crypto_checkdriver(hid);
+               /* Driver cannot disappear when there is an active session. */
+               KASSERT(cap != NULL, ("%s: Driver disappeared.", __func__));
+               if (!cap->cc_qblocked) {
+                       crypto_all_qblocked = 0;
+                       crypto_drivers[hid].cc_unqblocked = 1;
+                       CRYPTO_Q_UNLOCK();
+                       result = crypto_invoke(cap, crp, 0);
+                       CRYPTO_Q_LOCK();
+                       if (result == ERESTART)
+                               if (crypto_drivers[hid].cc_unqblocked)
+                                       crypto_drivers[hid].cc_qblocked = 1;
+                       crypto_drivers[hid].cc_unqblocked = 0;
+               }
+       }
+       if (result == ERESTART) {
+               /*
+                * The driver ran out of resources, mark the
+                * driver ``blocked'' for cryptop's and put
+                * the request back in the queue.  It would
+                * best to put the request back where we got
+                * it but that's hard so for now we put it
+                * at the front.  This should be ok; putting
+                * it at the end does not work.
+                */
+               list_add(&crp->crp_next, &crp_q);
+               cryptostats.cs_blocks++;
+               result = 0;
+       } else if (result == -1) {
+               TAILQ_INSERT_TAIL(&crp_q, crp, crp_next);
+               result = 0;
+       }
+       if (crp_sleep)
+               wake_up_interruptible(&cryptoproc_wait);
+       CRYPTO_Q_UNLOCK();
+       return result;
+}
+
+/*
+ * Add an asymetric crypto request to a queue,
+ * to be processed by the kernel thread.
+ */
+int
+crypto_kdispatch(struct cryptkop *krp)
+{
+       int error;
+       unsigned long q_flags;
+
+       cryptostats.cs_kops++;
+
+       error = crypto_kinvoke(krp, krp->krp_crid);
+       if (error == ERESTART) {
+               CRYPTO_Q_LOCK();
+               TAILQ_INSERT_TAIL(&crp_kq, krp, krp_next);
+               if (crp_sleep)
+                       wake_up_interruptible(&cryptoproc_wait);
+               CRYPTO_Q_UNLOCK();
+               error = 0;
+       }
+       return error;
+}
+
+/*
+ * Verify a driver is suitable for the specified operation.
+ */
+static __inline int
+kdriver_suitable(const struct cryptocap *cap, const struct cryptkop *krp)
+{
+       return (cap->cc_kalg[krp->krp_op] & CRYPTO_ALG_FLAG_SUPPORTED) != 0;
+}
+
+/*
+ * Select a driver for an asym operation.  The driver must
+ * support the necessary algorithm.  The caller can constrain
+ * which device is selected with the flags parameter.  The
+ * algorithm we use here is pretty stupid; just use the first
+ * driver that supports the algorithms we need. If there are
+ * multiple suitable drivers we choose the driver with the
+ * fewest active operations.  We prefer hardware-backed
+ * drivers to software ones when either may be used.
+ */
+static struct cryptocap *
+crypto_select_kdriver(const struct cryptkop *krp, int flags)
+{
+       struct cryptocap *cap, *best, *blocked;
+       int match, hid;
+
+       CRYPTO_DRIVER_ASSERT();
+
+       /*
+        * Look first for hardware crypto devices if permitted.
+        */
+       if (flags & CRYPTOCAP_F_HARDWARE)
+               match = CRYPTOCAP_F_HARDWARE;
+       else
+               match = CRYPTOCAP_F_SOFTWARE;
+       best = NULL;
+       blocked = NULL;
+again:
+       for (hid = 0; hid < crypto_drivers_num; hid++) {
+               cap = &crypto_drivers[hid];
+               /*
+                * If it's not initialized, is in the process of
+                * going away, or is not appropriate (hardware
+                * or software based on match), then skip.
+                */
+               if (cap->cc_dev == NULL ||
+                   (cap->cc_flags & CRYPTOCAP_F_CLEANUP) ||
+                   (cap->cc_flags & match) == 0)
+                       continue;
+
+               /* verify all the algorithms are supported. */
+               if (kdriver_suitable(cap, krp)) {
+                       if (best == NULL ||
+                           cap->cc_koperations < best->cc_koperations)
+                               best = cap;
+               }
+       }
+       if (best != NULL)
+               return best;
+       if (match == CRYPTOCAP_F_HARDWARE && (flags & CRYPTOCAP_F_SOFTWARE)) {
+               /* sort of an Algol 68-style for loop */
+               match = CRYPTOCAP_F_SOFTWARE;
+               goto again;
+       }
+       return best;
+}
+
+/*
+ * Dispatch an assymetric crypto request.
+ */
+static int
+crypto_kinvoke(struct cryptkop *krp, int crid)
+{
+       struct cryptocap *cap = NULL;
+       int error;
+       unsigned long d_flags;
+
+       KASSERT(krp != NULL, ("%s: krp == NULL", __func__));
+       KASSERT(krp->krp_callback != NULL,
+           ("%s: krp->crp_callback == NULL", __func__));
+
+       CRYPTO_DRIVER_LOCK();
+       if ((crid & (CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE)) == 0) {
+               cap = crypto_checkdriver(crid);
+               if (cap != NULL) {
+                       /*
+                        * Driver present, it must support the necessary
+                        * algorithm and, if s/w drivers are excluded,
+                        * it must be registered as hardware-backed.
+                        */
+                       if (!kdriver_suitable(cap, krp) ||
+                           (!crypto_devallowsoft &&
+                            (cap->cc_flags & CRYPTOCAP_F_HARDWARE) == 0))
+                               cap = NULL;
+               }
+       } else {
+               /*
+                * No requested driver; select based on crid flags.
+                */
+               if (!crypto_devallowsoft)       /* NB: disallow s/w drivers */
+                       crid &= ~CRYPTOCAP_F_SOFTWARE;
+               cap = crypto_select_kdriver(krp, crid);
+       }
+       if (cap != NULL && !cap->cc_kqblocked) {
+               krp->krp_hid = cap - crypto_drivers;
+               cap->cc_koperations++;
+               CRYPTO_DRIVER_UNLOCK();
+               error = CRYPTODEV_KPROCESS(cap->cc_dev, krp, 0);
+               CRYPTO_DRIVER_LOCK();
+               if (error == ERESTART) {
+                       cap->cc_koperations--;
+                       CRYPTO_DRIVER_UNLOCK();
+                       return (error);
+               }
+               /* return the actual device used */
+               krp->krp_crid = krp->krp_hid;
+       } else {
+               /*
+                * NB: cap is !NULL if device is blocked; in
+                *     that case return ERESTART so the operation
+                *     is resubmitted if possible.
+                */
+               error = (cap == NULL) ? ENODEV : ERESTART;
+       }
+       CRYPTO_DRIVER_UNLOCK();
+
+       if (error) {
+               krp->krp_status = error;
+               crypto_kdone(krp);
+       }
+       return 0;
+}
+
+
+/*
+ * Dispatch a crypto request to the appropriate crypto devices.
+ */
+static int
+crypto_invoke(struct cryptocap *cap, struct cryptop *crp, int hint)
+{
+       KASSERT(crp != NULL, ("%s: crp == NULL", __func__));
+       KASSERT(crp->crp_callback != NULL,
+           ("%s: crp->crp_callback == NULL", __func__));
+       KASSERT(crp->crp_desc != NULL, ("%s: crp->crp_desc == NULL", __func__));
+
+       dprintk("%s()\n", __FUNCTION__);
+
+#ifdef CRYPTO_TIMING
+       if (crypto_timing)
+               crypto_tstat(&cryptostats.cs_invoke, &crp->crp_tstamp);
+#endif
+       if (cap->cc_flags & CRYPTOCAP_F_CLEANUP) {
+               struct cryptodesc *crd;
+               u_int64_t nid;
+
+               /*
+                * Driver has unregistered; migrate the session and return
+                * an error to the caller so they'll resubmit the op.
+                *
+                * XXX: What if there are more already queued requests for this
+                *      session?
+                */
+               crypto_freesession(crp->crp_sid);
+
+               for (crd = crp->crp_desc; crd->crd_next; crd = crd->crd_next)
+                       crd->CRD_INI.cri_next = &(crd->crd_next->CRD_INI);
+
+               /* XXX propagate flags from initial session? */
+               if (crypto_newsession(&nid, &(crp->crp_desc->CRD_INI),
+                   CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE) == 0)
+                       crp->crp_sid = nid;
+
+               crp->crp_etype = EAGAIN;
+               crypto_done(crp);
+               return 0;
+       } else {
+               /*
+                * Invoke the driver to process the request.
+                */
+               return CRYPTODEV_PROCESS(cap->cc_dev, crp, hint);
+       }
+}
+
+/*
+ * Release a set of crypto descriptors.
+ */
+void
+crypto_freereq(struct cryptop *crp)
+{
+       struct cryptodesc *crd;
+
+       if (crp == NULL)
+               return;
+
+#ifdef DIAGNOSTIC
+       {
+               struct cryptop *crp2;
+               unsigned long q_flags;
+
+               CRYPTO_Q_LOCK();
+               TAILQ_FOREACH(crp2, &crp_q, crp_next) {
+                       KASSERT(crp2 != crp,
+                           ("Freeing cryptop from the crypto queue (%p).",
+                           crp));
+               }
+               CRYPTO_Q_UNLOCK();
+               CRYPTO_RETQ_LOCK();
+               TAILQ_FOREACH(crp2, &crp_ret_q, crp_next) {
+                       KASSERT(crp2 != crp,
+                           ("Freeing cryptop from the return queue (%p).",
+                           crp));
+               }
+               CRYPTO_RETQ_UNLOCK();
+       }
+#endif
+
+       while ((crd = crp->crp_desc) != NULL) {
+               crp->crp_desc = crd->crd_next;
+               kmem_cache_free(cryptodesc_zone, crd);
+       }
+       kmem_cache_free(cryptop_zone, crp);
+}
+
+/*
+ * Acquire a set of crypto descriptors.
+ */
+struct cryptop *
+crypto_getreq(int num)
+{
+       struct cryptodesc *crd;
+       struct cryptop *crp;
+
+       crp = kmem_cache_alloc(cryptop_zone, SLAB_ATOMIC);
+       if (crp != NULL) {
+               memset(crp, 0, sizeof(*crp));
+               INIT_LIST_HEAD(&crp->crp_next);
+               init_waitqueue_head(&crp->crp_waitq);
+               while (num--) {
+                       crd = kmem_cache_alloc(cryptodesc_zone, SLAB_ATOMIC);
+                       if (crd == NULL) {
+                               crypto_freereq(crp);
+                               return NULL;
+                       }
+                       memset(crd, 0, sizeof(*crd));
+                       crd->crd_next = crp->crp_desc;
+                       crp->crp_desc = crd;
+               }
+       }
+       return crp;
+}
+
+/*
+ * Invoke the callback on behalf of the driver.
+ */
+void
+crypto_done(struct cryptop *crp)
+{
+       unsigned long q_flags;
+
+       dprintk("%s()\n", __FUNCTION__);
+       if ((crp->crp_flags & CRYPTO_F_DONE) == 0) {
+               crp->crp_flags |= CRYPTO_F_DONE;
+               CRYPTO_Q_LOCK();
+               crypto_q_cnt--;
+               CRYPTO_Q_UNLOCK();
+       } else
+               printk("crypto: crypto_done op already done, flags 0x%x",
+                               crp->crp_flags);
+       if (crp->crp_etype != 0)
+               cryptostats.cs_errs++;
+       /*
+        * CBIMM means unconditionally do the callback immediately;
+        * CBIFSYNC means do the callback immediately only if the
+        * operation was done synchronously.  Both are used to avoid
+        * doing extraneous context switches; the latter is mostly
+        * used with the software crypto driver.
+        */
+       if ((crp->crp_flags & CRYPTO_F_CBIMM) ||
+           ((crp->crp_flags & CRYPTO_F_CBIFSYNC) &&
+            (CRYPTO_SESID2CAPS(crp->crp_sid) & CRYPTOCAP_F_SYNC))) {
+               /*
+                * Do the callback directly.  This is ok when the
+                * callback routine does very little (e.g. the
+                * /dev/crypto callback method just does a wakeup).
+                */
+               crp->crp_callback(crp);
+       } else {
+               unsigned long r_flags;
+               /*
+                * Normal case; queue the callback for the thread.
+                */
+               CRYPTO_RETQ_LOCK();
+               if (CRYPTO_RETQ_EMPTY())
+                       wake_up_interruptible(&cryptoretproc_wait);/* shared wait channel */
+               TAILQ_INSERT_TAIL(&crp_ret_q, crp, crp_next);
+               CRYPTO_RETQ_UNLOCK();
+       }
+}
+
+/*
+ * Invoke the callback on behalf of the driver.
+ */
+void
+crypto_kdone(struct cryptkop *krp)
+{
+       struct cryptocap *cap;
+       unsigned long d_flags;
+
+       if ((krp->krp_flags & CRYPTO_KF_DONE) != 0)
+               printk("crypto: crypto_kdone op already done, flags 0x%x",
+                               krp->krp_flags);
+       krp->krp_flags |= CRYPTO_KF_DONE;
+       if (krp->krp_status != 0)
+               cryptostats.cs_kerrs++;
+
+       CRYPTO_DRIVER_LOCK();
+       /* XXX: What if driver is loaded in the meantime? */
+       if (krp->krp_hid < crypto_drivers_num) {
+               cap = &crypto_drivers[krp->krp_hid];
+               cap->cc_koperations--;
+               KASSERT(cap->cc_koperations >= 0, ("cc_koperations < 0"));
+               if (cap->cc_flags & CRYPTOCAP_F_CLEANUP)
+                       crypto_remove(cap);
+       }
+       CRYPTO_DRIVER_UNLOCK();
+
+       /*
+        * CBIMM means unconditionally do the callback immediately;
+        * This is used to avoid doing extraneous context switches
+        */
+       if ((krp->krp_flags & CRYPTO_KF_CBIMM)) {
+               /*
+                * Do the callback directly.  This is ok when the
+                * callback routine does very little (e.g. the
+                * /dev/crypto callback method just does a wakeup).
+                */
+               krp->krp_callback(krp);
+       } else {
+               unsigned long r_flags;
+               /*
+                * Normal case; queue the callback for the thread.
+                */
+               CRYPTO_RETQ_LOCK();
+               if (CRYPTO_RETQ_EMPTY())
+                       wake_up_interruptible(&cryptoretproc_wait);/* shared wait channel */
+               TAILQ_INSERT_TAIL(&crp_ret_kq, krp, krp_next);
+               CRYPTO_RETQ_UNLOCK();
+       }
+}
+
+int
+crypto_getfeat(int *featp)
+{
+       int hid, kalg, feat = 0;
+       unsigned long d_flags;
+
+       CRYPTO_DRIVER_LOCK();
+       for (hid = 0; hid < crypto_drivers_num; hid++) {
+               const struct cryptocap *cap = &crypto_drivers[hid];
+
+               if ((cap->cc_flags & CRYPTOCAP_F_SOFTWARE) &&
+                   !crypto_devallowsoft) {
+                       continue;
+               }
+               for (kalg = 0; kalg < CRK_ALGORITHM_MAX; kalg++)
+                       if (cap->cc_kalg[kalg] & CRYPTO_ALG_FLAG_SUPPORTED)
+                               feat |=  1 << kalg;
+       }
+       CRYPTO_DRIVER_UNLOCK();
+       *featp = feat;
+       return (0);
+}
+
+/*
+ * Crypto thread, dispatches crypto requests.
+ */
+static int
+crypto_proc(void *arg)
+{
+       struct cryptop *crp, *submit;
+       struct cryptkop *krp, *krpp;
+       struct cryptocap *cap;
+       u_int32_t hid;
+       int result, hint;
+       unsigned long q_flags;
+       int loopcount = 0;
+
+       ocf_daemonize("crypto");
+
+       CRYPTO_Q_LOCK();
+       for (;;) {
+               /*
+                * we need to make sure we don't get into a busy loop with nothing
+                * to do,  the two crypto_all_*blocked vars help us find out when
+                * we are all full and can do nothing on any driver or Q.  If so we
+                * wait for an unblock.
+                */
+               crypto_all_qblocked  = !list_empty(&crp_q);
+
+               /*
+                * Find the first element in the queue that can be
+                * processed and look-ahead to see if multiple ops
+                * are ready for the same driver.
+                */
+               submit = NULL;
+               hint = 0;
+               list_for_each_entry(crp, &crp_q, crp_next) {
+                       hid = CRYPTO_SESID2HID(crp->crp_sid);
+                       cap = crypto_checkdriver(hid);
+                       /*
+                        * Driver cannot disappear when there is an active
+                        * session.
+                        */
+                       KASSERT(cap != NULL, ("%s:%u Driver disappeared.",
+                           __func__, __LINE__));
+                       if (cap == NULL || cap->cc_dev == NULL) {
+                               /* Op needs to be migrated, process it. */
+                               if (submit == NULL)
+                                       submit = crp;
+                               break;
+                       }
+                       if (!cap->cc_qblocked) {
+                               if (submit != NULL) {
+                                       /*
+                                        * We stop on finding another op,
+                                        * regardless whether its for the same
+                                        * driver or not.  We could keep
+                                        * searching the queue but it might be
+                                        * better to just use a per-driver
+                                        * queue instead.
+                                        */
+                                       if (CRYPTO_SESID2HID(submit->crp_sid) == hid)
+                                               hint = CRYPTO_HINT_MORE;
+                                       break;
+                               } else {
+                                       submit = crp;
+                                       if ((submit->crp_flags & CRYPTO_F_BATCH) == 0)
+                                               break;
+                                       /* keep scanning for more are q'd */
+                               }
+                       }
+               }
+               if (submit != NULL) {
+                       hid = CRYPTO_SESID2HID(submit->crp_sid);
+                       crypto_all_qblocked = 0;
+                       list_del(&submit->crp_next);
+                       crypto_drivers[hid].cc_unqblocked = 1;
+                       cap = crypto_checkdriver(hid);
+                       CRYPTO_Q_UNLOCK();
+                       KASSERT(cap != NULL, ("%s:%u Driver disappeared.",
+                           __func__, __LINE__));
+                       result = crypto_invoke(cap, submit, hint);
+                       CRYPTO_Q_LOCK();
+                       if (result == ERESTART) {
+                               /*
+                                * The driver ran out of resources, mark the
+                                * driver ``blocked'' for cryptop's and put
+                                * the request back in the queue.  It would
+                                * best to put the request back where we got
+                                * it but that's hard so for now we put it
+                                * at the front.  This should be ok; putting
+                                * it at the end does not work.
+                                */
+                               /* XXX validate sid again? */
+                               list_add(&submit->crp_next, &crp_q);
+                               cryptostats.cs_blocks++;
+                               if (crypto_drivers[hid].cc_unqblocked)
+                                       crypto_drivers[hid].cc_qblocked=0;
+                               crypto_drivers[hid].cc_unqblocked=0;
+                       }
+                       crypto_drivers[hid].cc_unqblocked = 0;
+               }
+
+               crypto_all_kqblocked = !list_empty(&crp_kq);
+
+               /* As above, but for key ops */
+               krp = NULL;
+               list_for_each_entry(krpp, &crp_kq, krp_next) {
+                       cap = crypto_checkdriver(krpp->krp_hid);
+                       if (cap == NULL || cap->cc_dev == NULL) {
+                               /*
+                                * Operation needs to be migrated, invalidate
+                                * the assigned device so it will reselect a
+                                * new one below.  Propagate the original
+                                * crid selection flags if supplied.
+                                */
+                               krp->krp_hid = krp->krp_crid &
+                                   (CRYPTOCAP_F_SOFTWARE|CRYPTOCAP_F_HARDWARE);
+                               if (krp->krp_hid == 0)
+                                       krp->krp_hid =
+                                   CRYPTOCAP_F_SOFTWARE|CRYPTOCAP_F_HARDWARE;
+                               break;
+                       }
+                       if (!cap->cc_kqblocked) {
+                               krp = krpp;
+                               break;
+                       }
+               }
+               if (krp != NULL) {
+                       crypto_all_kqblocked = 0;
+                       list_del(&krp->krp_next);
+                       crypto_drivers[krp->krp_hid].cc_kqblocked = 1;
+                       CRYPTO_Q_UNLOCK();
+                       result = crypto_kinvoke(krp, krp->krp_hid);
+                       CRYPTO_Q_LOCK();
+                       if (result == ERESTART) {
+                               /*
+                                * The driver ran out of resources, mark the
+                                * driver ``blocked'' for cryptkop's and put
+                                * the request back in the queue.  It would
+                                * best to put the request back where we got
+                                * it but that's hard so for now we put it
+                                * at the front.  This should be ok; putting
+                                * it at the end does not work.
+                                */
+                               /* XXX validate sid again? */
+                               list_add(&krp->krp_next, &crp_kq);
+                               cryptostats.cs_kblocks++;
+                       } else
+                               crypto_drivers[krp->krp_hid].cc_kqblocked = 0;
+               }
+
+               if (submit == NULL && krp == NULL) {
+                       /*
+                        * Nothing more to be processed.  Sleep until we're
+                        * woken because there are more ops to process.
+                        * This happens either by submission or by a driver
+                        * becoming unblocked and notifying us through
+                        * crypto_unblock.  Note that when we wakeup we
+                        * start processing each queue again from the
+                        * front. It's not clear that it's important to
+                        * preserve this ordering since ops may finish
+                        * out of order if dispatched to different devices
+                        * and some become blocked while others do not.
+                        */
+                       dprintk("%s - sleeping (qe=%d qb=%d kqe=%d kqb=%d)\n",
+                                       __FUNCTION__,
+                                       list_empty(&crp_q), crypto_all_qblocked,
+                                       list_empty(&crp_kq), crypto_all_kqblocked);
+                       loopcount = 0;
+                       CRYPTO_Q_UNLOCK();
+                       crp_sleep = 1;
+                       wait_event_interruptible(cryptoproc_wait,
+                                       !(list_empty(&crp_q) || crypto_all_qblocked) ||
+                                       !(list_empty(&crp_kq) || crypto_all_kqblocked) ||
+                                       cryptoproc == (pid_t) -1);
+                       crp_sleep = 0;
+                       if (signal_pending (current)) {
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+                               spin_lock_irq(&current->sigmask_lock);
+#endif
+                               flush_signals(current);
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+                               spin_unlock_irq(&current->sigmask_lock);
+#endif
+                       }
+                       CRYPTO_Q_LOCK();
+                       dprintk("%s - awake\n", __FUNCTION__);
+                       if (cryptoproc == (pid_t) -1)
+                               break;
+                       cryptostats.cs_intrs++;
+               } else if (loopcount > crypto_max_loopcount) {
+                       /*
+                        * Give other processes a chance to run if we've 
+                        * been using the CPU exclusively for a while.
+                        */
+                       loopcount = 0;
+                       schedule();
+               }
+               loopcount++;
+       }
+       CRYPTO_Q_UNLOCK();
+       complete_and_exit(&cryptoproc_exited, 0);
+}
+
+/*
+ * Crypto returns thread, does callbacks for processed crypto requests.
+ * Callbacks are done here, rather than in the crypto drivers, because
+ * callbacks typically are expensive and would slow interrupt handling.
+ */
+static int
+crypto_ret_proc(void *arg)
+{
+       struct cryptop *crpt;
+       struct cryptkop *krpt;
+       unsigned long  r_flags;
+
+       ocf_daemonize("crypto_ret");
+
+       CRYPTO_RETQ_LOCK();
+       for (;;) {
+               /* Harvest return q's for completed ops */
+               crpt = NULL;
+               if (!list_empty(&crp_ret_q))
+                       crpt = list_entry(crp_ret_q.next, typeof(*crpt), crp_next);
+               if (crpt != NULL)
+                       list_del(&crpt->crp_next);
+
+               krpt = NULL;
+               if (!list_empty(&crp_ret_kq))
+                       krpt = list_entry(crp_ret_kq.next, typeof(*krpt), krp_next);
+               if (krpt != NULL)
+                       list_del(&krpt->krp_next);
+
+               if (crpt != NULL || krpt != NULL) {
+                       CRYPTO_RETQ_UNLOCK();
+                       /*
+                        * Run callbacks unlocked.
+                        */
+                       if (crpt != NULL)
+                               crpt->crp_callback(crpt);
+                       if (krpt != NULL)
+                               krpt->krp_callback(krpt);
+                       CRYPTO_RETQ_LOCK();
+               } else {
+                       /*
+                        * Nothing more to be processed.  Sleep until we're
+                        * woken because there are more returns to process.
+                        */
+                       dprintk("%s - sleeping\n", __FUNCTION__);
+                       CRYPTO_RETQ_UNLOCK();
+                       wait_event_interruptible(cryptoretproc_wait,
+                                       cryptoretproc == (pid_t) -1 ||
+                                       !list_empty(&crp_ret_q) ||
+                                       !list_empty(&crp_ret_kq));
+                       if (signal_pending (current)) {
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+                               spin_lock_irq(&current->sigmask_lock);
+#endif
+                               flush_signals(current);
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
+                               spin_unlock_irq(&current->sigmask_lock);
+#endif
+                       }
+                       CRYPTO_RETQ_LOCK();
+                       dprintk("%s - awake\n", __FUNCTION__);
+                       if (cryptoretproc == (pid_t) -1) {
+                               dprintk("%s - EXITING!\n", __FUNCTION__);
+                               break;
+                       }
+                       cryptostats.cs_rets++;
+               }
+       }
+       CRYPTO_RETQ_UNLOCK();
+       complete_and_exit(&cryptoretproc_exited, 0);
+}
+
+
+#if 0 /* should put this into /proc or something */
+static void
+db_show_drivers(void)
+{
+       int hid;
+
+       db_printf("%12s %4s %4s %8s %2s %2s\n"
+               , "Device"
+               , "Ses"
+               , "Kops"
+               , "Flags"
+               , "QB"
+               , "KB"
+       );
+       for (hid = 0; hid < crypto_drivers_num; hid++) {
+               const struct cryptocap *cap = &crypto_drivers[hid];
+               if (cap->cc_dev == NULL)
+                       continue;
+               db_printf("%-12s %4u %4u %08x %2u %2u\n"
+                   , device_get_nameunit(cap->cc_dev)
+                   , cap->cc_sessions
+                   , cap->cc_koperations
+                   , cap->cc_flags
+                   , cap->cc_qblocked
+                   , cap->cc_kqblocked
+               );
+       }
+}
+
+DB_SHOW_COMMAND(crypto, db_show_crypto)
+{
+       struct cryptop *crp;
+
+       db_show_drivers();
+       db_printf("\n");
+
+       db_printf("%4s %8s %4s %4s %4s %4s %8s %8s\n",
+           "HID", "Caps", "Ilen", "Olen", "Etype", "Flags",
+           "Desc", "Callback");
+       TAILQ_FOREACH(crp, &crp_q, crp_next) {
+               db_printf("%4u %08x %4u %4u %4u %04x %8p %8p\n"
+                   , (int) CRYPTO_SESID2HID(crp->crp_sid)
+                   , (int) CRYPTO_SESID2CAPS(crp->crp_sid)
+                   , crp->crp_ilen, crp->crp_olen
+                   , crp->crp_etype
+                   , crp->crp_flags
+                   , crp->crp_desc
+                   , crp->crp_callback
+               );
+       }
+       if (!TAILQ_EMPTY(&crp_ret_q)) {
+               db_printf("\n%4s %4s %4s %8s\n",
+                   "HID", "Etype", "Flags", "Callback");
+               TAILQ_FOREACH(crp, &crp_ret_q, crp_next) {
+                       db_printf("%4u %4u %04x %8p\n"
+                           , (int) CRYPTO_SESID2HID(crp->crp_sid)
+                           , crp->crp_etype
+                           , crp->crp_flags
+                           , crp->crp_callback
+                       );
+               }
+       }
+}
+
+DB_SHOW_COMMAND(kcrypto, db_show_kcrypto)
+{
+       struct cryptkop *krp;
+
+       db_show_drivers();
+       db_printf("\n");
+
+       db_printf("%4s %5s %4s %4s %8s %4s %8s\n",
+           "Op", "Status", "#IP", "#OP", "CRID", "HID", "Callback");
+       TAILQ_FOREACH(krp, &crp_kq, krp_next) {
+               db_printf("%4u %5u %4u %4u %08x %4u %8p\n"
+                   , krp->krp_op
+                   , krp->krp_status
+                   , krp->krp_iparams, krp->krp_oparams
+                   , krp->krp_crid, krp->krp_hid
+                   , krp->krp_callback
+               );
+       }
+       if (!TAILQ_EMPTY(&crp_ret_q)) {
+               db_printf("%4s %5s %8s %4s %8s\n",
+                   "Op", "Status", "CRID", "HID", "Callback");
+               TAILQ_FOREACH(krp, &crp_ret_kq, krp_next) {
+                       db_printf("%4u %5u %08x %4u %8p\n"
+                           , krp->krp_op
+                           , krp->krp_status
+                           , krp->krp_crid, krp->krp_hid
+                           , krp->krp_callback
+                       );
+               }
+       }
+}
+#endif
+
+
+static int
+crypto_init(void)
+{
+       int error;
+
+       dprintk("%s(%p)\n", __FUNCTION__, (void *) crypto_init);
+
+       if (crypto_initted)
+               return 0;
+       crypto_initted = 1;
+
+       spin_lock_init(&crypto_drivers_lock);
+       spin_lock_init(&crypto_q_lock);
+       spin_lock_init(&crypto_ret_q_lock);
+
+       cryptop_zone = kmem_cache_create("cryptop", sizeof(struct cryptop),
+                                      0, SLAB_HWCACHE_ALIGN, NULL
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
+                                      , NULL
+#endif
+                                       );
+
+       cryptodesc_zone = kmem_cache_create("cryptodesc", sizeof(struct cryptodesc),
+                                      0, SLAB_HWCACHE_ALIGN, NULL
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
+                                      , NULL
+#endif
+                                       );
+
+       if (cryptodesc_zone == NULL || cryptop_zone == NULL) {
+               printk("crypto: crypto_init cannot setup crypto zones\n");
+               error = ENOMEM;
+               goto bad;
+       }
+
+       crypto_drivers_num = CRYPTO_DRIVERS_INITIAL;
+       crypto_drivers = kmalloc(crypto_drivers_num * sizeof(struct cryptocap),
+                       GFP_KERNEL);
+       if (crypto_drivers == NULL) {
+               printk("crypto: crypto_init cannot setup crypto drivers\n");
+               error = ENOMEM;
+               goto bad;
+       }
+
+       memset(crypto_drivers, 0, crypto_drivers_num * sizeof(struct cryptocap));
+
+       init_completion(&cryptoproc_exited);
+       init_completion(&cryptoretproc_exited);
+
+       cryptoproc = 0; /* to avoid race condition where proc runs first */
+       cryptoproc = kernel_thread(crypto_proc, NULL, CLONE_FS|CLONE_FILES);
+       if (cryptoproc < 0) {
+               error = cryptoproc;
+               printk("crypto: crypto_init cannot start crypto thread; error %d",
+                       error);
+               goto bad;
+       }
+
+       cryptoretproc = 0; /* to avoid race condition where proc runs first */
+       cryptoretproc = kernel_thread(crypto_ret_proc, NULL, CLONE_FS|CLONE_FILES);
+       if (cryptoretproc < 0) {
+               error = cryptoretproc;
+               printk("crypto: crypto_init cannot start cryptoret thread; error %d",
+                               error);
+               goto bad;
+       }
+
+       return 0;
+bad:
+       crypto_exit();
+       return error;
+}
+
+
+static void
+crypto_exit(void)
+{
+       pid_t p;
+       unsigned long d_flags;
+
+       dprintk("%s()\n", __FUNCTION__);
+
+       /*
+        * Terminate any crypto threads.
+        */
+
+       CRYPTO_DRIVER_LOCK();
+       p = cryptoproc;
+       cryptoproc = (pid_t) -1;
+       kill_proc(p, SIGTERM, 1);
+       wake_up_interruptible(&cryptoproc_wait);
+       CRYPTO_DRIVER_UNLOCK();
+
+       wait_for_completion(&cryptoproc_exited);
+
+       CRYPTO_DRIVER_LOCK();
+       p = cryptoretproc;
+       cryptoretproc = (pid_t) -1;
+       kill_proc(p, SIGTERM, 1);
+       wake_up_interruptible(&cryptoretproc_wait);
+       CRYPTO_DRIVER_UNLOCK();
+
+       wait_for_completion(&cryptoretproc_exited);
+
+       /* XXX flush queues??? */
+
+       /* 
+        * Reclaim dynamically allocated resources.
+        */
+       if (crypto_drivers != NULL)
+               kfree(crypto_drivers);
+
+       if (cryptodesc_zone != NULL)
+               kmem_cache_destroy(cryptodesc_zone);
+       if (cryptop_zone != NULL)
+               kmem_cache_destroy(cryptop_zone);
+}
+
+
+EXPORT_SYMBOL(crypto_newsession);
+EXPORT_SYMBOL(crypto_freesession);
+EXPORT_SYMBOL(crypto_get_driverid);
+EXPORT_SYMBOL(crypto_kregister);
+EXPORT_SYMBOL(crypto_register);
+EXPORT_SYMBOL(crypto_unregister);
+EXPORT_SYMBOL(crypto_unregister_all);
+EXPORT_SYMBOL(crypto_unblock);
+EXPORT_SYMBOL(crypto_dispatch);
+EXPORT_SYMBOL(crypto_kdispatch);
+EXPORT_SYMBOL(crypto_freereq);
+EXPORT_SYMBOL(crypto_getreq);
+EXPORT_SYMBOL(crypto_done);
+EXPORT_SYMBOL(crypto_kdone);
+EXPORT_SYMBOL(crypto_getfeat);
+EXPORT_SYMBOL(crypto_userasymcrypto);
+EXPORT_SYMBOL(crypto_getcaps);
+EXPORT_SYMBOL(crypto_find_driver);
+EXPORT_SYMBOL(crypto_find_device_byhid);
+
+module_init(crypto_init);
+module_exit(crypto_exit);
+
+MODULE_LICENSE("BSD");
+MODULE_AUTHOR("David McCullough <david_mccullough@mcafee.com>");
+MODULE_DESCRIPTION("OCF (OpenBSD Cryptographic Framework)");