Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

=============

CRYPTO ENGINE

=============

Overview

--------

The crypto engine API (CE), is a crypto queue manager.

Requirement

-----------

You have to put at start of your tfm_ctx the struct crypto_engine_ctx

struct your_tfm_ctx {

        struct crypto_engine_ctx enginectx;

        ...

};

Why: Since CE manage only crypto_async_request, it cannot know the underlying

request_type and so have access only on the TFM.

So using container_of for accessing __ctx is impossible.

Furthermore, the crypto engine cannot know the "struct your_tfm_ctx",

so it must assume that crypto_engine_ctx is at start of it.

Order of operations

-------------------

You have to obtain a struct crypto_engine via crypto_engine_alloc_init().

And start it via crypto_engine_start().

Before transferring any request, you have to fill the enginectx.

- prepare_request: (taking a function pointer) If you need to do some processing before doing the request

- unprepare_request: (taking a function pointer) Undoing what's done in prepare_request

- do_one_request: (taking a function pointer) Do encryption for current request

Note: that those three functions get the crypto_async_request associated with the received request.

So your need to get the original request via container_of(areq, struct yourrequesttype_request, base);

When your driver receive a crypto_request, you have to transfer it to

the cryptoengine via one of:

- crypto_transfer_ablkcipher_request_to_engine()

- crypto_transfer_aead_request_to_engine()

- crypto_transfer_akcipher_request_to_engine()

- crypto_transfer_hash_request_to_engine()

- crypto_transfer_skcipher_request_to_engine()

At the end of the request process, a call to one of the following function is needed:

- crypto_finalize_ablkcipher_request

- crypto_finalize_aead_request

- crypto_finalize_akcipher_request

- crypto_finalize_hash_request

- crypto_finalize_skcipher_request

                               |

                               '---------------> HASH2

Note that it is perfectly legal to "abandon" a request object:

- call .init() and then (as many times) .update()

- _not_ call any of .final(), .finup() or .export() at any point in future

In other words implementations should mind the resource allocation and clean-up.

No resources related to request objects should remain allocated after a call

to .init() or .update(), since there might be no chance to free them.

Specifics Of Asynchronous HASH Transformation

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Arm TrustZone CryptoCell cryptographic engine

Required properties:

- compatible: Should be "arm,cryptocell-712-ree".

- compatible: Should be one of: "arm,cryptocell-712-ree",

  "arm,cryptocell-710-ree" or "arm,cryptocell-630p-ree".

- reg: Base physical address of the engine and length of memory mapped region.

- interrupts: Interrupt number for the device.

- interrupt-names: Should be "ring0", "ring1", "ring2", "ring3", "eip", "mem".

Optional properties:

- clocks: Reference to the crypto engine clock.

- clocks: Reference to the crypto engine clocks, the second clock is

          needed for the Armada 7K/8K SoCs.

- clock-names: mandatory if there is a second clock, in this case the

               name must be "core" for the first clock and "reg" for

               the second one.

Example:

Freescale RNGC (Random Number Generator Version C)

The driver also supports version B, which is mostly compatible

to version C.

Freescale RNGA/RNGB/RNGC (Random Number Generator Versions A, B and C)

Required properties:

- compatible : should be one of

               "fsl,imx21-rnga"

               "fsl,imx31-rnga" (backward compatible with "fsl,imx21-rnga")

               "fsl,imx25-rngb"

               "fsl,imx35-rngc"

- reg : offset and length of the register set of this block

- interrupts : the interrupt number for the RNGC block

- clocks : the RNGC clk source

- interrupts : the interrupt number for the RNG block

- clocks : the RNG clk source

Example: