/*
 * Cryptographic API for algorithms (i.e., low-level API).
 *
 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option) 
 * any later version.
 *
 */
#ifndef _CRYPTO_ALGAPI_H
#define _CRYPTO_ALGAPI_H

#include <linux/crypto.h>
#include <linux/list.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/skbuff.h>

struct crypto_aead;
struct crypto_instance;
struct module;
struct rtattr;
struct seq_file;

struct crypto_type {
        unsigned int (*ctxsize)(struct crypto_alg *alg, u32 type, u32 mask);
        unsigned int (*extsize)(struct crypto_alg *alg);
        int (*init)(struct crypto_tfm *tfm, u32 type, u32 mask);
        int (*init_tfm)(struct crypto_tfm *tfm);
        void (*show)(struct seq_file *m, struct crypto_alg *alg);
        int (*report)(struct sk_buff *skb, struct crypto_alg *alg);
        struct crypto_alg *(*lookup)(const char *name, u32 type, u32 mask);
        void (*free)(struct crypto_instance *inst);

        unsigned int type;
        unsigned int maskclear;
        unsigned int maskset;
        unsigned int tfmsize;
};

struct crypto_instance {
        struct crypto_alg alg;

        struct crypto_template *tmpl;
        struct hlist_node list;

        void *__ctx[] CRYPTO_MINALIGN_ATTR;
};

struct crypto_template {
        struct list_head list;
        struct hlist_head instances;
        struct module *module;

        struct crypto_instance *(*alloc)(struct rtattr **tb);
        void (*free)(struct crypto_instance *inst);
        int (*create)(struct crypto_template *tmpl, struct rtattr **tb);

        char name[CRYPTO_MAX_ALG_NAME];
};

struct crypto_spawn {
        struct list_head list;
        struct crypto_alg *alg;
        struct crypto_instance *inst;
        const struct crypto_type *frontend;
        u32 mask;
};

struct crypto_queue {
        struct list_head list;
        struct list_head *backlog;

        unsigned int qlen;
        unsigned int max_qlen;
};

struct scatter_walk {
        struct scatterlist *sg;
        unsigned int offset;
};

struct blkcipher_walk {
        union {
                struct {
                        struct page *page;
                        unsigned long offset;
                } phys;

                struct {
                        u8 *page;
                        u8 *addr;
                } virt;
        } src, dst;

        struct scatter_walk in;
        unsigned int nbytes;

        struct scatter_walk out;
        unsigned int total;

        void *page;
        u8 *buffer;
        u8 *iv;
        unsigned int ivsize;

        int flags;
        unsigned int walk_blocksize;
        unsigned int cipher_blocksize;
        unsigned int alignmask;
};

struct ablkcipher_walk {
        struct {
                struct page *page;
                unsigned int offset;
        } src, dst;

        struct scatter_walk     in;
        unsigned int            nbytes;
        struct scatter_walk     out;
        unsigned int            total;
        struct list_head        buffers;
        u8                      *iv_buffer;
        u8                      *iv;
        int                     flags;
        unsigned int            blocksize;
};

#define ENGINE_NAME_LEN 30
/*
 * struct crypto_engine - crypto hardware engine
 * @name: the engine name
 * @idling: the engine is entering idle state
 * @busy: request pump is busy
 * @running: the engine is on working
 * @cur_req_prepared: current request is prepared
 * @list: link with the global crypto engine list
 * @queue_lock: spinlock to syncronise access to request queue
 * @queue: the crypto queue of the engine
 * @rt: whether this queue is set to run as a realtime task
 * @prepare_crypt_hardware: a request will soon arrive from the queue
 * so the subsystem requests the driver to prepare the hardware
 * by issuing this call
 * @unprepare_crypt_hardware: there are currently no more requests on the
 * queue so the subsystem notifies the driver that it may relax the
 * hardware by issuing this call
 * @prepare_request: do some prepare if need before handle the current request
 * @unprepare_request: undo any work done by prepare_message()
 * @crypt_one_request: do encryption for current request
 * @kworker: thread struct for request pump
 * @kworker_task: pointer to task for request pump kworker thread
 * @pump_requests: work struct for scheduling work to the request pump
 * @priv_data: the engine private data
 * @cur_req: the current request which is on processing
 */
struct crypto_engine {
        char                    name[ENGINE_NAME_LEN];
        bool                    idling;
        bool                    busy;
        bool                    running;
        bool                    cur_req_prepared;

        struct list_head        list;
        spinlock_t              queue_lock;
        struct crypto_queue     queue;

        bool                    rt;

        int (*prepare_crypt_hardware)(struct crypto_engine *engine);
        int (*unprepare_crypt_hardware)(struct crypto_engine *engine);

        int (*prepare_request)(struct crypto_engine *engine,
                               struct ablkcipher_request *req);
        int (*unprepare_request)(struct crypto_engine *engine,
                                 struct ablkcipher_request *req);
        int (*crypt_one_request)(struct crypto_engine *engine,
                                 struct ablkcipher_request *req);

        struct kthread_worker           kworker;
        struct task_struct              *kworker_task;
        struct kthread_work             pump_requests;

        void                            *priv_data;
        struct ablkcipher_request       *cur_req;
};

int crypto_transfer_request(struct crypto_engine *engine,
                            struct ablkcipher_request *req, bool need_pump);
int crypto_transfer_request_to_engine(struct crypto_engine *engine,
                                      struct ablkcipher_request *req);
void crypto_finalize_request(struct crypto_engine *engine,
                             struct ablkcipher_request *req, int err);
int crypto_engine_start(struct crypto_engine *engine);
int crypto_engine_stop(struct crypto_engine *engine);
struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt);
int crypto_engine_exit(struct crypto_engine *engine);

extern const struct crypto_type crypto_ablkcipher_type;
extern const struct crypto_type crypto_blkcipher_type;

void crypto_mod_put(struct crypto_alg *alg);

int crypto_register_template(struct crypto_template *tmpl);
void crypto_unregister_template(struct crypto_template *tmpl);
struct crypto_template *crypto_lookup_template(const char *name);

int crypto_register_instance(struct crypto_template *tmpl,
                             struct crypto_instance *inst);
int crypto_unregister_instance(struct crypto_instance *inst);

int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
                      struct crypto_instance *inst, u32 mask);
int crypto_init_spawn2(struct crypto_spawn *spawn, struct crypto_alg *alg,
                       struct crypto_instance *inst,
                       const struct crypto_type *frontend);
int crypto_grab_spawn(struct crypto_spawn *spawn, const char *name,
                      u32 type, u32 mask);

void crypto_drop_spawn(struct crypto_spawn *spawn);
struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
                                    u32 mask);
void *crypto_spawn_tfm2(struct crypto_spawn *spawn);

static inline void crypto_set_spawn(struct crypto_spawn *spawn,
                                    struct crypto_instance *inst)
{
        spawn->inst = inst;
}

struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb);
int crypto_check_attr_type(struct rtattr **tb, u32 type);
const char *crypto_attr_alg_name(struct rtattr *rta);
struct crypto_alg *crypto_attr_alg2(struct rtattr *rta,
                                    const struct crypto_type *frontend,
                                    u32 type, u32 mask);

static inline struct crypto_alg *crypto_attr_alg(struct rtattr *rta,
                                                 u32 type, u32 mask)
{
        return crypto_attr_alg2(rta, NULL, type, mask);
}

int crypto_attr_u32(struct rtattr *rta, u32 *num);
void *crypto_alloc_instance2(const char *name, struct crypto_alg *alg,
                             unsigned int head);
struct crypto_instance *crypto_alloc_instance(const char *name,
                                              struct crypto_alg *alg);

void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen);
int crypto_enqueue_request(struct crypto_queue *queue,
                           struct crypto_async_request *request);
struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue);
int crypto_tfm_in_queue(struct crypto_queue *queue, struct crypto_tfm *tfm);
static inline unsigned int crypto_queue_len(struct crypto_queue *queue)
{
        return queue->qlen;
}

/* These functions require the input/output to be aligned as u32. */
void crypto_inc(u8 *a, unsigned int size);
void crypto_xor(u8 *dst, const u8 *src, unsigned int size);

int blkcipher_walk_done(struct blkcipher_desc *desc,
                        struct blkcipher_walk *walk, int err);
int blkcipher_walk_virt(struct blkcipher_desc *desc,
                        struct blkcipher_walk *walk);
int blkcipher_walk_phys(struct blkcipher_desc *desc,
                        struct blkcipher_walk *walk);
int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
                              struct blkcipher_walk *walk,
                              unsigned int blocksize);
int blkcipher_aead_walk_virt_block(struct blkcipher_desc *desc,
                                   struct blkcipher_walk *walk,
                                   struct crypto_aead *tfm,
                                   unsigned int blocksize);

int ablkcipher_walk_done(struct ablkcipher_request *req,
                         struct ablkcipher_walk *walk, int err);
int ablkcipher_walk_phys(struct ablkcipher_request *req,
                         struct ablkcipher_walk *walk);
void __ablkcipher_walk_complete(struct ablkcipher_walk *walk);

static inline void *crypto_tfm_ctx_aligned(struct crypto_tfm *tfm)
{
        return PTR_ALIGN(crypto_tfm_ctx(tfm),
                         crypto_tfm_alg_alignmask(tfm) + 1);
}

static inline struct crypto_instance *crypto_tfm_alg_instance(
        struct crypto_tfm *tfm)
{
        return container_of(tfm->__crt_alg, struct crypto_instance, alg);
}

static inline void *crypto_instance_ctx(struct crypto_instance *inst)
{
        return inst->__ctx;
}

static inline struct ablkcipher_alg *crypto_ablkcipher_alg(
        struct crypto_ablkcipher *tfm)
{
        return &crypto_ablkcipher_tfm(tfm)->__crt_alg->cra_ablkcipher;
}

static inline void *crypto_ablkcipher_ctx(struct crypto_ablkcipher *tfm)
{
        return crypto_tfm_ctx(&tfm->base);
}

static inline void *crypto_ablkcipher_ctx_aligned(struct crypto_ablkcipher *tfm)
{
        return crypto_tfm_ctx_aligned(&tfm->base);
}

static inline struct crypto_blkcipher *crypto_spawn_blkcipher(
        struct crypto_spawn *spawn)
{
        u32 type = CRYPTO_ALG_TYPE_BLKCIPHER;
        u32 mask = CRYPTO_ALG_TYPE_MASK;

        return __crypto_blkcipher_cast(crypto_spawn_tfm(spawn, type, mask));
}

static inline void *crypto_blkcipher_ctx(struct crypto_blkcipher *tfm)
{
        return crypto_tfm_ctx(&tfm->base);
}

static inline void *crypto_blkcipher_ctx_aligned(struct crypto_blkcipher *tfm)
{
        return crypto_tfm_ctx_aligned(&tfm->base);
}

static inline struct crypto_cipher *crypto_spawn_cipher(
        struct crypto_spawn *spawn)
{
        u32 type = CRYPTO_ALG_TYPE_CIPHER;
        u32 mask = CRYPTO_ALG_TYPE_MASK;

        return __crypto_cipher_cast(crypto_spawn_tfm(spawn, type, mask));
}

static inline struct cipher_alg *crypto_cipher_alg(struct crypto_cipher *tfm)
{
        return &crypto_cipher_tfm(tfm)->__crt_alg->cra_cipher;
}

static inline void blkcipher_walk_init(struct blkcipher_walk *walk,
                                       struct scatterlist *dst,
                                       struct scatterlist *src,
                                       unsigned int nbytes)
{
        walk->in.sg = src;
        walk->out.sg = dst;
        walk->total = nbytes;
}

static inline void ablkcipher_walk_init(struct ablkcipher_walk *walk,
                                        struct scatterlist *dst,
                                        struct scatterlist *src,
                                        unsigned int nbytes)
{
        walk->in.sg = src;
        walk->out.sg = dst;
        walk->total = nbytes;
        INIT_LIST_HEAD(&walk->buffers);
}

static inline void ablkcipher_walk_complete(struct ablkcipher_walk *walk)
{
        if (unlikely(!list_empty(&walk->buffers)))
                __ablkcipher_walk_complete(walk);
}

static inline struct crypto_async_request *crypto_get_backlog(
        struct crypto_queue *queue)
{
        return queue->backlog == &queue->list ? NULL :
               container_of(queue->backlog, struct crypto_async_request, list);
}

static inline int ablkcipher_enqueue_request(struct crypto_queue *queue,
                                             struct ablkcipher_request *request)
{
        return crypto_enqueue_request(queue, &request->base);
}

static inline struct ablkcipher_request *ablkcipher_dequeue_request(
        struct crypto_queue *queue)
{
        return ablkcipher_request_cast(crypto_dequeue_request(queue));
}

static inline void *ablkcipher_request_ctx(struct ablkcipher_request *req)
{
        return req->__ctx;
}

static inline int ablkcipher_tfm_in_queue(struct crypto_queue *queue,
                                          struct crypto_ablkcipher *tfm)
{
        return crypto_tfm_in_queue(queue, crypto_ablkcipher_tfm(tfm));
}

static inline struct crypto_alg *crypto_get_attr_alg(struct rtattr **tb,
                                                     u32 type, u32 mask)
{
        return crypto_attr_alg(tb[1], type, mask);
}

/*
 * Returns CRYPTO_ALG_ASYNC if type/mask requires the use of sync algorithms.
 * Otherwise returns zero.
 */
static inline int crypto_requires_sync(u32 type, u32 mask)
{
        return (type ^ CRYPTO_ALG_ASYNC) & mask & CRYPTO_ALG_ASYNC;
}

noinline unsigned long __crypto_memneq(const void *a, const void *b, size_t size);

/**
 * crypto_memneq - Compare two areas of memory without leaking
 *                 timing information.
 *
 * @a: One area of memory
 * @b: Another area of memory
 * @size: The size of the area.
 *
 * Returns 0 when data is equal, 1 otherwise.
 */
static inline int crypto_memneq(const void *a, const void *b, size_t size)
{
        return __crypto_memneq(a, b, size) != 0UL ? 1 : 0;
}

static inline void crypto_yield(u32 flags)
{
        if (flags & CRYPTO_TFM_REQ_MAY_SLEEP)
                cond_resched();
}

#endif  /* _CRYPTO_ALGAPI_H */