crypto: sha-mb - multibuffer crypto infrastructure

This patch introduces the multi-buffer crypto daemon which is responsible
for submitting crypto jobs in a work queue to the responsible multi-buffer
crypto algorithm.  The idea of the multi-buffer algorihtm is to put
data streams from multiple jobs in a wide (AVX2) register and then
take advantage of SIMD instructions to do crypto computation on several
buffers simultaneously.

The multi-buffer crypto daemon is also responsbile for flushing the
remaining buffers to complete the computation if no new buffers arrive
for a while.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

include/crypto/mcryptd.h

@@ -0,0 +1,112 @@
+/*
+ * Software async multibuffer crypto daemon headers
+ *
+ *    Author:
+ *             Tim Chen <tim.c.chen@linux.intel.com>
+ *
+ *    Copyright (c) 2014, Intel Corporation.
+ */
+
+#ifndef _CRYPTO_MCRYPT_H
+#define _CRYPTO_MCRYPT_H
+
+#include <linux/crypto.h>
+#include <linux/kernel.h>
+#include <crypto/hash.h>
+
+struct mcryptd_ahash {
+	struct crypto_ahash base;
+};
+
+static inline struct mcryptd_ahash *__mcryptd_ahash_cast(
+	struct crypto_ahash *tfm)
+{
+	return (struct mcryptd_ahash *)tfm;
+}
+
+struct mcryptd_cpu_queue {
+	struct crypto_queue queue;
+	struct work_struct work;
+};
+
+struct mcryptd_queue {
+	struct mcryptd_cpu_queue __percpu *cpu_queue;
+};
+
+struct mcryptd_instance_ctx {
+	struct crypto_spawn spawn;
+	struct mcryptd_queue *queue;
+};
+
+struct mcryptd_hash_ctx {
+	struct crypto_shash *child;
+	struct mcryptd_alg_state *alg_state;
+};
+
+struct mcryptd_tag {
+	/* seq number of request */
+	unsigned seq_num;
+	/* arrival time of request */
+	unsigned long arrival;
+	unsigned long expire;
+	int	cpu;
+};
+
+struct mcryptd_hash_request_ctx {
+	struct list_head waiter;
+	crypto_completion_t complete;
+	struct mcryptd_tag tag;
+	struct crypto_hash_walk walk;
+	u8 *out;
+	int flag;
+	struct shash_desc desc;
+};
+
+struct mcryptd_ahash *mcryptd_alloc_ahash(const char *alg_name,
+					u32 type, u32 mask);
+struct crypto_shash *mcryptd_ahash_child(struct mcryptd_ahash *tfm);
+struct shash_desc *mcryptd_shash_desc(struct ahash_request *req);
+void mcryptd_free_ahash(struct mcryptd_ahash *tfm);
+void mcryptd_flusher(struct work_struct *work);
+
+enum mcryptd_req_type {
+	MCRYPTD_NONE,
+	MCRYPTD_UPDATE,
+	MCRYPTD_FINUP,
+	MCRYPTD_DIGEST,
+	MCRYPTD_FINAL
+};
+
+struct mcryptd_alg_cstate {
+	unsigned long next_flush;
+	unsigned next_seq_num;
+	bool	flusher_engaged;
+	struct  delayed_work flush;
+	int	cpu;
+	struct  mcryptd_alg_state *alg_state;
+	void	*mgr;
+	spinlock_t work_lock;
+	struct list_head work_list;
+	struct list_head flush_list;
+};
+
+struct mcryptd_alg_state {
+	struct mcryptd_alg_cstate __percpu *alg_cstate;
+	unsigned long (*flusher)(struct mcryptd_alg_cstate *cstate);
+};
+
+/* return delay in jiffies from current time */
+static inline unsigned long get_delay(unsigned long t)
+{
+	long delay;
+
+	delay = (long) t - (long) jiffies;
+	if (delay <= 0)
+		return 0;
+	else
+		return (unsigned long) delay;
+}
+
+void mcryptd_arm_flusher(struct mcryptd_alg_cstate *cstate, unsigned long delay);
+
+#endif