Re: [PATCH 3/3] crypto: qce: ice: Add support for Inline Crypto Engine
From: Randy Dunlap
Date: Wed Oct 17 2018 - 13:39:19 EST
On 10/17/18 8:17 AM, AnilKumar Chimata wrote:
> This patch adds support for Inline Crypto Engine (ICE), which
> is embedded into storage device/controller such as UFS/eMMC.
> ICE is intended for high throughput cryptographic encryption
> or decryption of storage data.
>
> Signed-off-by: AnilKumar Chimata <anilc@xxxxxxxxxxxxxx>
> ---
> Documentation/crypto/msm/ice.txt | 235 ++++++
> drivers/crypto/Kconfig | 10 +
> drivers/crypto/qce/Makefile | 1 +
> drivers/crypto/qce/ice.c | 1613 ++++++++++++++++++++++++++++++++++++++
> drivers/crypto/qce/iceregs.h | 159 ++++
> include/crypto/ice.h | 80 ++
> 6 files changed, 2098 insertions(+)
> create mode 100644 Documentation/crypto/msm/ice.txt
> create mode 100644 drivers/crypto/qce/ice.c
> create mode 100644 drivers/crypto/qce/iceregs.h
> create mode 100644 include/crypto/ice.h
>
> diff --git a/Documentation/crypto/msm/ice.txt b/Documentation/crypto/msm/ice.txt
> new file mode 100644
> index 0000000..58f7081
> --- /dev/null
> +++ b/Documentation/crypto/msm/ice.txt
> @@ -0,0 +1,235 @@
> +Introduction:
> +=============
> +Storage encryption has been one of the most required feature from security
features
> +point of view. QTI based storage encryption solution uses general purpose
> +crypto engine. While this kind of solution provide a decent amount of
provides
> +performance, it falls short as storage speed is improving significantly
> +continuously. To overcome performance degradation, newer chips are going to
> +have Inline Crypto Engine (ICE) embedded into storage device. ICE is supposed
> +to meet the line speed of storage devices.
> +
> +Hardware Description
> +====================
> +ICE is a HW block that is embedded into storage device such as UFS/eMMC. By
s/HW/hardware/ devices
> +default, ICE works in bypass mode i.e. ICE HW does not perform any crypto
> +operation on data to be processed by storage device. If required, ICE can be
> +configured to perform crypto operation in one direction (i.e. either encryption
> +or decryption) or in both direction(both encryption & decryption).
directions (both ...
> +
> +When a switch between the operation modes(plain to crypto or crypto to plain)
modes (plain ...
> +is desired for a particular partition, SW must complete all transactions for
s/SW/software/
> +that particular partition before switching the crypto mode i.e. no crypto, one
crypto mode;
> +direction crypto or both direction crypto operation. Requests for other
directions
> +partitions are not impacted due to crypto mode switch.
> +
> +ICE HW currently supports AES128/256 bit ECB & XTS mode encryption algorithms.
> +
> +Keys for crypto operations are loaded from SW. Keys are stored in a lookup
> +table(LUT) located inside ICE HW. Maximum of 32 keys can be loaded in ICE key
> +LUT. A Key inside the LUT can be referred using a key index.
referred to using
> +
> +SW Description
> +==============
> +ICE HW has categorized ICE registers in 2 groups: those which can be accessed by
> +only secure side i.e. TZ and those which can be accessed by non-secure side such
at least tell the reader what TZ and HLOS mean...
> +as HLOS as well. This requires that ICE driver to be split in two pieces: one
that the ICE driver be split into two pieces: one
> +running from TZ space and another from HLOS space.
> +
> +ICE driver from TZ would configure keys as requested by HLOS side.
> +
> +ICE driver on HLOS side is responsible for initialization of ICE HW.
> +
> +SW Architecture Diagram
> +=======================
> +Following are all the components involved in the ICE driver for control path:
> +
> ++++++++++++++++++++++++++++++++++++++++++
> ++ App layer +
> ++++++++++++++++++++++++++++++++++++++++++
> ++ System layer +
> ++ ++++++++ +++++++ +
> ++ + VOLD + + PFM + +
> ++ ++++++++ +++++++ +
> ++ || || +
> ++ || || +
> ++ \/ \/ +
> ++ +++++++++++++++++++++++++++ +
> ++ + LibQSEECom / cryptfs_hw + +
> ++ +++++++++++++++++++++++++++ +
> ++++++++++++++++++++++++++++++++++++++++++
> ++ Kernel + +++++++++++++++++
> ++ + + KMS +
> ++ +++++++ +++++++++++ +++++++++++ + +++++++++++++++++
> ++ + ICE + + Storage + + QSEECom + + + ICE Driver +
> ++++++++++++++++++++++++++++++++++++++++++ <===> +++++++++++++++++
> + || ||
> + || ||
> + \/ \/
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> ++ Storage Device +
> ++ ++++++++++++++ +
> ++ + ICE HW + +
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> +
> +Use Cases:
> +----------
> +a) Device bootup
> +ICE HW is detected during bootup time and corresponding probe function is
> +called. ICE driver parses its data from device tree node. ICE HW and storage
> +HW are tightly coupled. Storage device probing is dependent upon ICE device
> +probing. ICE driver configures all the required registers to put the ICE HW
> +in bypass mode.
> +
> +b) Configuring keys
> +Currently, there are couple of use cases to configure the keys.
> +
> +1) Full Disk Encryption(FDE)
> +System layer(VOLD) at invocation of apps layer would call libqseecom to create
> +the encryption key. Libqseecom calls qseecom driver to communicate with KMS
> +module on the secure side i.e. TZ. KMS would call ICE driver on the TZ side to
> +create and set the keys in ICE HW. At the end of transaction, VOLD would have
> +key index of key LUT where encryption key is present.
> +
> +2) Per File Encryption (PFE)
> +Per File Manager(PFM) calls QSEECom api to create the key. PFM has a peer comp-
Preferably don't split (hyphenate) "component." But if you must, it should be com-
ponent.
> +onent(PFT) at kernel layer which gets the corresponding key index from PFM.
> +
> +Following are all the components involved in the ICE driver for data path:
> +
> + +++++++++++++++++++++++++++++++++++++++++
> + + App layer +
> + +++++++++++++++++++++++++++++++++++++++++
> + + VFS +
> + +---------------------------------------+
> + + File System (EXT4) +
> + +---------------------------------------+
> + + Block Layer +
> + + --------------------------------------+
> + + +++++++ +
> + + dm-req-crypt => + PFT + +
> + + +++++++ +
> + + +
> + +---------------------------------------+
> + + +++++++++++ +++++++ +
> + + + Storage + + ICE + +
> + +++++++++++++++++++++++++++++++++++++++++
> + + || +
> + + || (Storage Req with +
> + + \/ ICE parameters ) +
> + +++++++++++++++++++++++++++++++++++++++++
> + + Storage Device +
> + + ++++++++++++++ +
> + + + ICE HW + +
> + +++++++++++++++++++++++++++++++++++++++++
> +
> +c) Data transaction
> +Once the crypto key has been configured, VOLD/PFM creates device mapping for
> +data partition. As part of device mapping VOLD passes key index, crypto
> +algorithm, mode and key length to dm layer. In case of PFE, keys are provided
> +by PFT as and when request is processed by dm-req-crypt. When any application
> +needs to read/write data, it would go through DM layer which would add crypto
> +information, provided by VOLD/PFT, to Request. For each Request, Storage driver
> +would ask ICE driver to configure crypto part of request. ICE driver extracts
> +crypto data from Request structure and provide it to storage driver which would
provides
> +finally dispatch request to storage device.
> +
> +d) Error Handling
> +Due to issue # 1 mentioned in "Known Issues", ICE driver does not register for
> +any interrupt. However, it enables sources of interrupt for ICE HW. After each
> +data transaction, Storage driver receives transaction completion event. As part
> +of event handling, storage driver calls ICE driver to check if any of ICE
> +interrupt status is set. If yes, storage driver returns error to upper layer.
> +
> +Error handling would be changed in future chips.
> +
> +Interfaces
> +==========
> +ICE driver exposes interfaces for storage driver to :
to:
> +1. Get the global instance of ICE driver
> +2. Get the implemented interfaces of the particular ice instance
> +3. Initialize the ICE HW
> +4. Reset the ICE HW
> +5. Resume/Suspend the ICE HW
> +6. Get the Crypto configuration for the data request for storage
> +7. Check if current data transaction has generated any interrupt
> +
> +Driver Parameters
> +=================
> +This driver is built and statically linked into the kernel; therefore,
> +there are no module parameters supported by this driver.
> +
> +There are no kernel command line parameters supported by this driver.
> +
> +Power Management
> +================
> +ICE driver does not do power management on its own as it is part of storage
> +hardware. Whenever storage driver receives request for power collapse/suspend
> +resume, it would call ICE driver which exposes APIs for Storage HW. ICE HW
> +during power collapse or reset, wipes crypto configuration data. When ICE
^no comma
> +driver receives request to resume, it would ask ICE driver on TZ side to
> +restore the configuration. ICE driver does not do anything as part of power
> +collapse or suspend event.
> +
> +Interface:
> +==========
> +ICE driver exposes following APIs for storage driver to use:
> +
> +int (*init)(struct platform_device *, void *, ice_success_cb, ice_error_cb);
> + -- This function is invoked by storage controller during initialization of
> + storage controller. Storage controller would provide success and error call
> + backs which would be invoked asynchronously once ICE HW init is done.
> +
> +int (*reset)(struct platform_device *);
> + -- ICE HW reset as part of storage controller reset. When storage controller
> + received reset command, it would call reset on ICE HW. As of now, ICE HW
> + does not need to do anything as part of reset.
> +
> +int (*resume)(struct platform_device *);
> + -- ICE HW while going to reset, wipes all crypto keys and other data from ICE
^no comma
> + HW. ICE driver would reconfigure those data as part of resume operation.
> +
> +int (*suspend)(struct platform_device *);
> + -- This API would be called by storage driver when storage device is going to
> + suspend mode. As of today, ICE driver does not do anything to handle suspend.
> +
> +int (*config)(struct platform_device *, struct request* , struct ice_data_setting*);
> + -- Storage driver would call this interface to get all crypto data required to
> + perform crypto operation.
> +
> +int (*status)(struct platform_device *);
> + -- Storage driver would call this interface to check if previous data transfer
> + generated any error.
> +
> +Config options
> +==============
> +This driver is enabled by the kernel config option CONFIG_CRYPTO_DEV_MSM_ICE.
> +
> +Dependencies
> +============
> +ICE driver depends upon corresponding ICE driver on TZ side to function
> +appropriately.
> +
> +Known Issues
> +============
> +1. ICE HW emits 0s even if it has generated an interrupt
That statement is unclear. Emits where? in a data stream? in interrupt status?
> +This issue has significant impact on how ICE interrupts are handled. Currently,
> +ICE driver does not register for any of the ICE interrupts but enables the
> +sources of interrupt. Once storage driver asks to check the status of interrupt,
> +it reads and clears the clear status and provide read status to storage driver.
"clears the clear status"??? s/provide/provides/
> +This mechanism though not optimal but prevents file-system corruption.
mangled sentence above.
> +This issue has been fixed in newer chips.
> +
> +2. ICE HW wipes all crypto data during power collapse
> +This issue necessitate that ICE driver on TZ side store the crypto material
necessitates
> +which is not required in the case of general purpose crypto engine.
> +This issue has been fixed in newer chips.
> +
> +Further Improvements
> +====================
> +Currently, Due to PFE use case, ICE driver is dependent upon dm-req-crypt to
due
> +provide the keys as part of request structure. This couples ICE driver with
> +dm-req-crypt based solution. It is under discussion to expose an IOCTL based
to expose IOCTL based
> +and registration based interface APIs from ICE driver. ICE driver would use
> +these two interfaces to find out if any key exists for current request. If
> +yes, choose the right key index received from IOCTL or registration based
> +APIs. If not, dont set any crypto parameter in the request.
don't
> diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
> index a8c4ce0..e40750e 100644
> --- a/drivers/crypto/Kconfig
> +++ b/drivers/crypto/Kconfig
> @@ -596,6 +596,16 @@ config CRYPTO_DEV_QCOM_RNG
> To compile this driver as a module, choose M here. The
> module will be called qcom-rng. If unsure, say N.
>
> +config CRYPTO_DEV_QTI_ICE
> + tristate "Qualcomm inline crypto engine accelerator"
> + default n
Please drop the redundant "default n" since n is already the default.
> + depends on (ARCH_QCOM || COMPILE_TEST) && BLK_DEV_DM
> + help
> + This driver supports Inline Crypto Engine for QTI chipsets, MSM8994
> + and later, to accelerate crypto operations for storage needs.
> + To compile this driver as a module, choose M here: the
> + module will be called ice.
> +
> config CRYPTO_DEV_VMX
> bool "Support for VMX cryptographic acceleration instructions"
> depends on PPC64 && VSX
--
~Randy