crypto: marvell/cesa - add TDMA support

The CESA IP supports CPU offload through a dedicated DMA engine (TDMA)
which can control the crypto block.
When you use this mode, all the required data (operation metadata and
payload data) are transferred using DMA, and the results are retrieved
through DMA when possible (hash results are not retrieved through DMA yet),
thus reducing the involvement of the CPU and providing better performances
in most cases (for small requests, the cost of DMA preparation might
exceed the performance gain).

Note that some CESA IPs do not embed this dedicated DMA, hence the
activation of this feature on a per platform basis.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 229 insertions, 0 deletions

diff --git a/drivers/crypto/marvell/cesa.h b/drivers/crypto/marvell/cesa.h
index f68057c7d96a..f8faf260b6d7 100644
--- a/drivers/crypto/marvell/cesa.h
+++ b/drivers/crypto/marvell/cesa.h
@@ -6,6 +6,7 @@
 #include <crypto/internal/hash.h>
 
 #include <linux/crypto.h>
+#include <linux/dmapool.h>
 
 #define CESA_ENGINE_OFF(i)			(((i) * 0x2000))
 
@@ -267,11 +268,94 @@ struct mv_cesa_op_ctx {
 	} ctx;
 };
 
+/* TDMA descriptor flags */
+#define CESA_TDMA_DST_IN_SRAM			BIT(31)
+#define CESA_TDMA_SRC_IN_SRAM			BIT(30)
+#define CESA_TDMA_TYPE_MSK			GENMASK(29, 0)
+#define CESA_TDMA_DUMMY				0
+#define CESA_TDMA_DATA				1
+#define CESA_TDMA_OP				2
+
+/**
+ * struct mv_cesa_tdma_desc - TDMA descriptor
+ * @byte_cnt:	number of bytes to transfer
+ * @src:	DMA address of the source
+ * @dst:	DMA address of the destination
+ * @next_dma:	DMA address of the next TDMA descriptor
+ * @cur_dma:	DMA address of this TDMA descriptor
+ * @next:	pointer to the next TDMA descriptor
+ * @op:		CESA operation attached to this TDMA descriptor
+ * @data:	raw data attached to this TDMA descriptor
+ * @flags:	flags describing the TDMA transfer. See the
+ *		"TDMA descriptor flags" section above
+ *
+ * TDMA descriptor used to create a transfer chain describing a crypto
+ * operation.
+ */
+struct mv_cesa_tdma_desc {
+	u32 byte_cnt;
+	u32 src;
+	u32 dst;
+	u32 next_dma;
+	u32 cur_dma;
+	struct mv_cesa_tdma_desc *next;
+	union {
+		struct mv_cesa_op_ctx *op;
+		void *data;
+	};
+	u32 flags;
+};
+
+/**
+ * struct mv_cesa_sg_dma_iter - scatter-gather iterator
+ * @dir:	transfer direction
+ * @sg:		scatter list
+ * @offset:	current position in the scatter list
+ * @op_offset:	current position in the crypto operation
+ *
+ * Iterator used to iterate over a scatterlist while creating a TDMA chain for
+ * a crypto operation.
+ */
+struct mv_cesa_sg_dma_iter {
+	enum dma_data_direction dir;
+	struct scatterlist *sg;
+	unsigned int offset;
+	unsigned int op_offset;
+};
+
+/**
+ * struct mv_cesa_dma_iter - crypto operation iterator
+ * @len:	the crypto operation length
+ * @offset:	current position in the crypto operation
+ * @op_len:	sub-operation length (the crypto engine can only act on 2kb
+ *		chunks)
+ *
+ * Iterator used to create a TDMA chain for a given crypto operation.
+ */
+struct mv_cesa_dma_iter {
+	unsigned int len;
+	unsigned int offset;
+	unsigned int op_len;
+};
+
+/**
+ * struct mv_cesa_tdma_chain - TDMA chain
+ * @first:	first entry in the TDMA chain
+ * @last:	last entry in the TDMA chain
+ *
+ * Stores a TDMA chain for a specific crypto operation.
+ */
+struct mv_cesa_tdma_chain {
+	struct mv_cesa_tdma_desc *first;
+	struct mv_cesa_tdma_desc *last;
+};
+
 struct mv_cesa_engine;
 
 /**
  * struct mv_cesa_caps - CESA device capabilities
  * @engines:		number of engines
+ * @has_tdma:		whether this device has a TDMA block
  * @cipher_algs:	supported cipher algorithms
  * @ncipher_algs:	number of supported cipher algorithms
  * @ahash_algs:		supported hash algorithms
@@ -281,6 +365,7 @@ struct mv_cesa_engine;
  */
 struct mv_cesa_caps {
 	int nengines;
+	bool has_tdma;
 	struct crypto_alg **cipher_algs;
 	int ncipher_algs;
 	struct ahash_alg **ahash_algs;
@@ -288,6 +373,24 @@ struct mv_cesa_caps {
 };
 
 /**
+ * struct mv_cesa_dev_dma - DMA pools
+ * @tdma_desc_pool:	TDMA desc pool
+ * @op_pool:		crypto operation pool
+ * @cache_pool:		data cache pool (used by hash implementation when the
+ *			hash request is smaller than the hash block size)
+ * @padding_pool:	padding pool (used by hash implementation when hardware
+ *			padding cannot be used)
+ *
+ * Structure containing the different DMA pools used by this driver.
+ */
+struct mv_cesa_dev_dma {
+	struct dma_pool *tdma_desc_pool;
+	struct dma_pool *op_pool;
+	struct dma_pool *cache_pool;
+	struct dma_pool *padding_pool;
+};
+
+/**
  * struct mv_cesa_dev - CESA device
  * @caps:	device capabilities
  * @regs:	device registers
@@ -295,6 +398,7 @@ struct mv_cesa_caps {
  * @lock:	device lock
  * @queue:	crypto request queue
  * @engines:	array of engines
+ * @dma:	dma pools
  *
  * Structure storing CESA device information.
  */
@@ -306,6 +410,7 @@ struct mv_cesa_dev {
 	spinlock_t lock;
 	struct crypto_queue queue;
 	struct mv_cesa_engine *engines;
+	struct mv_cesa_dev_dma *dma;
 };
 
 /**
@@ -391,9 +496,11 @@ struct mv_cesa_hmac_ctx {
 /**
  * enum mv_cesa_req_type - request type definitions
  * @CESA_STD_REQ:	standard request
+ * @CESA_DMA_REQ:	DMA request
  */
 enum mv_cesa_req_type {
 	CESA_STD_REQ,
+	CESA_DMA_REQ,
 };
 
 /**
@@ -407,6 +514,27 @@ struct mv_cesa_req {
 };
 
 /**
+ * struct mv_cesa_tdma_req - CESA TDMA request
+ * @base:	base information
+ * @chain:	TDMA chain
+ */
+struct mv_cesa_tdma_req {
+	struct mv_cesa_req base;
+	struct mv_cesa_tdma_chain chain;
+};
+
+/**
+ * struct mv_cesa_sg_std_iter - CESA scatter-gather iterator for standard
+ *				requests
+ * @iter:	sg mapping iterator
+ * @offset:	current offset in the SG entry mapped in memory
+ */
+struct mv_cesa_sg_std_iter {
+	struct sg_mapping_iter iter;
+	unsigned int offset;
+};
+
+/**
  * struct mv_cesa_ablkcipher_std_req - cipher standard request
  * @base:	base information
  * @op:		operation context
@@ -430,6 +558,7 @@ struct mv_cesa_ablkcipher_std_req {
 struct mv_cesa_ablkcipher_req {
 	union {
 		struct mv_cesa_req base;
+		struct mv_cesa_tdma_req dma;
 		struct mv_cesa_ablkcipher_std_req std;
 	} req;
 	int src_nents;
@@ -447,6 +576,20 @@ struct mv_cesa_ahash_std_req {
 };
 
 /**
+ * struct mv_cesa_ahash_dma_req - DMA hash request
+ * @base:		base information
+ * @padding:		padding buffer
+ * @padding_dma:	DMA address of the padding buffer
+ * @cache_dma:		DMA address of the cache buffer
+ */
+struct mv_cesa_ahash_dma_req {
+	struct mv_cesa_tdma_req base;
+	u8 *padding;
+	dma_addr_t padding_dma;
+	dma_addr_t cache_dma;
+};
+
+/**
  * struct mv_cesa_ahash_req - hash request
  * @req:		type specific request information
  * @cache:		cache buffer
@@ -460,6 +603,7 @@ struct mv_cesa_ahash_std_req {
 struct mv_cesa_ahash_req {
 	union {
 		struct mv_cesa_req base;
+		struct mv_cesa_ahash_dma_req dma;
 		struct mv_cesa_ahash_std_req std;
 	} req;
 	struct mv_cesa_op_ctx op_tmpl;
@@ -543,6 +687,91 @@ static inline u32 mv_cesa_get_int_mask(struct mv_cesa_engine *engine)
 
 int mv_cesa_queue_req(struct crypto_async_request *req);
 
+/* TDMA functions */
+
+static inline void mv_cesa_req_dma_iter_init(struct mv_cesa_dma_iter *iter,
+					     unsigned int len)
+{
+	iter->len = len;
+	iter->op_len = min(len, CESA_SA_SRAM_PAYLOAD_SIZE);
+	iter->offset = 0;
+}
+
+static inline void mv_cesa_sg_dma_iter_init(struct mv_cesa_sg_dma_iter *iter,
+					    struct scatterlist *sg,
+					    enum dma_data_direction dir)
+{
+	iter->op_offset = 0;
+	iter->offset = 0;
+	iter->sg = sg;
+	iter->dir = dir;
+}
+
+static inline unsigned int
+mv_cesa_req_dma_iter_transfer_len(struct mv_cesa_dma_iter *iter,
+				  struct mv_cesa_sg_dma_iter *sgiter)
+{
+	return min(iter->op_len - sgiter->op_offset,
+		   sg_dma_len(sgiter->sg) - sgiter->offset);
+}
+
+bool mv_cesa_req_dma_iter_next_transfer(struct mv_cesa_dma_iter *chain,
+					struct mv_cesa_sg_dma_iter *sgiter,
+					unsigned int len);
+
+static inline bool mv_cesa_req_dma_iter_next_op(struct mv_cesa_dma_iter *iter)
+{
+	iter->offset += iter->op_len;
+	iter->op_len = min(iter->len - iter->offset,
+			   CESA_SA_SRAM_PAYLOAD_SIZE);
+
+	return iter->op_len;
+}
+
+void mv_cesa_dma_step(struct mv_cesa_tdma_req *dreq);
+
+static inline int mv_cesa_dma_process(struct mv_cesa_tdma_req *dreq,
+				      u32 status)
+{
+	if (!(status & CESA_SA_INT_ACC0_IDMA_DONE))
+		return -EINPROGRESS;
+
+	if (status & CESA_SA_INT_IDMA_OWN_ERR)
+		return -EINVAL;
+
+	return 0;
+}
+
+void mv_cesa_dma_prepare(struct mv_cesa_tdma_req *dreq,
+			 struct mv_cesa_engine *engine);
+
+void mv_cesa_dma_cleanup(struct mv_cesa_tdma_req *dreq);
+
+static inline void
+mv_cesa_tdma_desc_iter_init(struct mv_cesa_tdma_chain *chain)
+{
+	memset(chain, 0, sizeof(*chain));
+}
+
+struct mv_cesa_op_ctx *mv_cesa_dma_add_op(struct mv_cesa_tdma_chain *chain,
+					const struct mv_cesa_op_ctx *op_templ,
+					bool skip_ctx,
+					gfp_t flags);
+
+int mv_cesa_dma_add_data_transfer(struct mv_cesa_tdma_chain *chain,
+				  dma_addr_t dst, dma_addr_t src, u32 size,
+				  u32 flags, gfp_t gfp_flags);
+
+int mv_cesa_dma_add_dummy_launch(struct mv_cesa_tdma_chain *chain,
+				 u32 flags);
+
+int mv_cesa_dma_add_dummy_end(struct mv_cesa_tdma_chain *chain, u32 flags);
+
+int mv_cesa_dma_add_op_transfers(struct mv_cesa_tdma_chain *chain,
+				 struct mv_cesa_dma_iter *dma_iter,
+				 struct mv_cesa_sg_dma_iter *sgiter,
+				 gfp_t gfp_flags);
+
 /* Algorithm definitions */
 
 extern struct ahash_alg mv_sha1_alg;