root/drivers/crypto/gemini/sl3516-ce.h
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * sl3516-ce.h - hardware cryptographic offloader for cortina/gemini SoC
 *
 * Copyright (C) 2021 Corentin LABBE <clabbe@baylibre.com>
 *
 * General notes on this driver:
 * Called either Crypto Acceleration Engine Module, Security Acceleration Engine
 * or IPSEC module in the datasheet, it will be called Crypto Engine for short
 * in this driver.
 * The CE was designed to handle IPSEC and wifi(TKIP WEP) protocol.
 * It can handle AES, DES, 3DES, MD5, WEP, TKIP, SHA1, HMAC(MD5), HMAC(SHA1),
 * Michael cipher/digest suites.
 * It acts the same as a network hw, with both RX and TX chained descriptors.
 */
#include <crypto/aes.h>
#include <crypto/engine.h>
#include <crypto/scatterwalk.h>
#include <crypto/skcipher.h>
#include <linux/debugfs.h>
#include <linux/hw_random.h>

#define TQ0_TYPE_DATA 0
#define TQ0_TYPE_CTRL BIT(0)
#define TQ1_CIPHER BIT(1)
#define TQ2_AUTH BIT(2)
#define TQ3_IV BIT(3)
#define TQ4_KEY0 BIT(4)
#define TQ5_KEY4 BIT(5)
#define TQ6_KEY6 BIT(6)
#define TQ7_AKEY0 BIT(7)
#define TQ8_AKEY2 BIT(8)
#define TQ9_AKEY2 BIT(9)

#define ECB_AES       0x2

#define DESC_LAST 0x01
#define DESC_FIRST 0x02

#define IPSEC_ID                0x0000
#define IPSEC_STATUS_REG        0x00a8
#define IPSEC_RAND_NUM_REG      0x00ac
#define IPSEC_DMA_DEVICE_ID     0xff00
#define IPSEC_DMA_STATUS        0xff04
#define IPSEC_TXDMA_CTRL        0xff08
#define IPSEC_TXDMA_FIRST_DESC  0xff0c
#define IPSEC_TXDMA_CURR_DESC   0xff10
#define IPSEC_RXDMA_CTRL        0xff14
#define IPSEC_RXDMA_FIRST_DESC  0xff18
#define IPSEC_RXDMA_CURR_DESC   0xff1c
#define IPSEC_TXDMA_BUF_ADDR    0xff28
#define IPSEC_RXDMA_BUF_ADDR    0xff38
#define IPSEC_RXDMA_BUF_SIZE    0xff30

#define CE_ENCRYPTION           0x01
#define CE_DECRYPTION           0x03

#define MAXDESC 6

#define DMA_STATUS_RS_EOFI      BIT(22)
#define DMA_STATUS_RS_PERR      BIT(24)
#define DMA_STATUS_RS_DERR      BIT(25)
#define DMA_STATUS_TS_EOFI      BIT(27)
#define DMA_STATUS_TS_PERR      BIT(29)
#define DMA_STATUS_TS_DERR      BIT(30)

#define TXDMA_CTRL_START BIT(31)
#define TXDMA_CTRL_CONTINUE BIT(30)
#define TXDMA_CTRL_CHAIN_MODE BIT(29)
/* the burst value is not documented in the datasheet */
#define TXDMA_CTRL_BURST_UNK BIT(22)
#define TXDMA_CTRL_INT_FAIL BIT(17)
#define TXDMA_CTRL_INT_PERR BIT(16)

#define RXDMA_CTRL_START BIT(31)
#define RXDMA_CTRL_CONTINUE BIT(30)
#define RXDMA_CTRL_CHAIN_MODE BIT(29)
/* the burst value is not documented in the datasheet */
#define RXDMA_CTRL_BURST_UNK BIT(22)
#define RXDMA_CTRL_INT_FINISH BIT(18)
#define RXDMA_CTRL_INT_FAIL BIT(17)
#define RXDMA_CTRL_INT_PERR BIT(16)
#define RXDMA_CTRL_INT_EOD BIT(15)
#define RXDMA_CTRL_INT_EOF BIT(14)

#define CE_CPU 0
#define CE_DMA 1

/*
 * struct sl3516_ce_descriptor - descriptor for CE operations
 * @frame_ctrl:         Information for the current descriptor
 * @flag_status:        For send packet, describe flag of operations.
 * @buf_adr:            pointer to a send/recv buffer for data packet
 * @next_desc:          control linking to other descriptors
 */
struct descriptor {
        union {
                u32 raw;
                /*
                 * struct desc_frame_ctrl - Information for the current descriptor
                 * @buffer_size:        the size of buffer at buf_adr
                 * @desc_count:         Upon completion of a DMA operation, DMA
                 *                      write the number of descriptors used
                 *                      for the current frame
                 * @checksum:           unknown
                 * @authcomp:           unknown
                 * @perr:               Protocol error during processing this descriptor
                 * @derr:               Data error during processing this descriptor
                 * @own:                0 if owned by CPU, 1 for DMA
                 */
                struct desc_frame_ctrl {
                        u32 buffer_size :16;
                        u32 desc_count  :6;
                        u32 checksum    :6;
                        u32 authcomp    :1;
                        u32 perr        :1;
                        u32 derr        :1;
                        u32 own         :1;
                } bits;
        } frame_ctrl;

        union {
                u32 raw;
                /*
                 * struct desc_flag_status - flag for this descriptor
                 * @tqflag:     list of flag describing the type of operation
                 *              to be performed.
                 */
                struct desc_tx_flag_status {
                        u32 tqflag      :10;
                        u32 unused      :22;
                } tx_flag;
        } flag_status;

        u32 buf_adr;

        union {
                u32 next_descriptor;
                /*
                 * struct desc_next - describe chaining of descriptors
                 * @sof_eof:    does the descriptor is first (0x11),
                 *              the last (0x01), middle of a chan (0x00)
                 *              or the only one (0x11)
                 * @dec:        AHB bus address increase (0), decrease (1)
                 * @eofie:      End of frame interrupt enable
                 * @ndar:       Next descriptor address
                 */
                struct desc_next {
                        u32 sof_eof     :2;
                        u32 dec         :1;
                        u32 eofie       :1;
                        u32 ndar        :28;
                } bits;
        } next_desc;
};

/*
 * struct control - The value of this register is used to set the
 *                      operation mode of the IPSec Module.
 * @process_id:         Used to identify the process. The number will be copied
 *                      to the descriptor status of the received packet.
 * @auth_check_len:     Number of 32-bit words to be checked or appended by the
 *                      authentication module
 * @auth_algorithm:
 * @auth_mode:          0:append 1:Check Authentication Result
 * @fcs_stream_copy:    0:enable 1:disable authentication stream copy
 * @mix_key_sel:        0:use rCipherKey0-3  1:use Key Mixer
 * @aesnk:              AES Key Size
 * @cipher_algorithm:   choice of CBC/ECE and AES/DES/3DES
 * @op_mode:            Operation Mode for the IPSec Module
 */
struct pkt_control_header {
        u32 process_id          :8;
        u32 auth_check_len      :3;
        u32 un1                 :1;
        u32 auth_algorithm      :3;
        u32 auth_mode           :1;
        u32 fcs_stream_copy     :1;
        u32 un2                 :2;
        u32 mix_key_sel         :1;
        u32 aesnk               :4;
        u32 cipher_algorithm    :3;
        u32 un3                 :1;
        u32 op_mode             :4;
};

struct pkt_control_cipher {
        u32 algorithm_len       :16;
        u32 header_len          :16;
};

/*
 * struct pkt_control_ecb - control packet for ECB
 */
struct pkt_control_ecb {
        struct pkt_control_header control;
        struct pkt_control_cipher cipher;
        unsigned char key[AES_MAX_KEY_SIZE];
};

/*
 * struct sl3516_ce_dev - main container for all this driver information
 * @base:       base address
 * @clks:       clocks used
 * @reset:      pointer to reset controller
 * @dev:        the platform device
 * @engine:     ptr to the crypto/crypto_engine
 * @complete:   completion for the current task on this flow
 * @status:     set to 1 by interrupt if task is done
 * @dtx:        base DMA address for TX descriptors
 * @tx          base address of TX descriptors
 * @drx:        base DMA address for RX descriptors
 * @rx          base address of RX descriptors
 * @ctx         current used TX descriptor
 * @crx         current used RX descriptor
 * @trng        hw_random structure for RNG
 * @hwrng_stat_req      number of HWRNG requests
 * @hwrng_stat_bytes    total number of bytes generated by RNG
 * @stat_irq    number of IRQ handled by CE
 * @stat_irq_tx number of TX IRQ handled by CE
 * @stat_irq_rx number of RX IRQ handled by CE
 * @stat_req    number of requests handled by CE
 * @fallbak_sg_count_tx         number of fallback due to destination SG count
 * @fallbak_sg_count_rx         number of fallback due to source SG count
 * @fallbak_not_same_len        number of fallback due to difference in SG length
 * @dbgfs_dir:  Debugfs dentry for statistic directory
 * @dbgfs_stats: Debugfs dentry for statistic counters
 */
struct sl3516_ce_dev {
        void __iomem *base;
        struct clk *clks;
        struct reset_control *reset;
        struct device *dev;
        struct crypto_engine *engine;
        struct completion complete;
        int status;
        dma_addr_t dtx;
        struct descriptor *tx;
        dma_addr_t drx;
        struct descriptor *rx;
        int ctx;
        int crx;
        struct hwrng trng;
        unsigned long hwrng_stat_req;
        unsigned long hwrng_stat_bytes;
        unsigned long stat_irq;
        unsigned long stat_irq_tx;
        unsigned long stat_irq_rx;
        unsigned long stat_req;
        unsigned long fallback_sg_count_tx;
        unsigned long fallback_sg_count_rx;
        unsigned long fallback_not_same_len;
        unsigned long fallback_mod16;
        unsigned long fallback_align16;
#ifdef CONFIG_CRYPTO_DEV_SL3516_DEBUG
        struct dentry *dbgfs_dir;
        struct dentry *dbgfs_stats;
#endif
        void *pctrl;
        dma_addr_t dctrl;
};

struct sginfo {
        u32 addr;
        u32 len;
};

/*
 * struct sl3516_ce_cipher_req_ctx - context for a skcipher request
 * @t_src:              list of mapped SGs with their size
 * @t_dst:              list of mapped SGs with their size
 * @op_dir:             direction (encrypt vs decrypt) for this request
 * @pctrllen:           the length of the ctrl packet
 * @tqflag:             the TQflag to set in data packet
 * @h                   pointer to the pkt_control_cipher header
 * @nr_sgs:             number of source SG
 * @nr_sgd:             number of destination SG
 * @fallback_req:       request struct for invoking the fallback skcipher TFM
 */
struct sl3516_ce_cipher_req_ctx {
        struct sginfo t_src[MAXDESC];
        struct sginfo t_dst[MAXDESC];
        u32 op_dir;
        unsigned int pctrllen;
        u32 tqflag;
        struct pkt_control_cipher *h;
        int nr_sgs;
        int nr_sgd;
        struct skcipher_request fallback_req;   // keep at the end
};

/*
 * struct sl3516_ce_cipher_tfm_ctx - context for a skcipher TFM
 * @key:                pointer to key data
 * @keylen:             len of the key
 * @ce:                 pointer to the private data of driver handling this TFM
 * @fallback_tfm:       pointer to the fallback TFM
 */
struct sl3516_ce_cipher_tfm_ctx {
        u32 *key;
        u32 keylen;
        struct sl3516_ce_dev *ce;
        struct crypto_skcipher *fallback_tfm;
};

/*
 * struct sl3516_ce_alg_template - crypto_alg template
 * @type:               the CRYPTO_ALG_TYPE for this template
 * @mode:               value to be used in control packet for this algorithm
 * @ce:                 pointer to the sl3516_ce_dev structure associated with
 *                      this template
 * @alg:                one of sub struct must be used
 * @stat_req:           number of request done on this template
 * @stat_fb:            number of request which has fallbacked
 * @stat_bytes:         total data size done by this template
 */
struct sl3516_ce_alg_template {
        u32 type;
        u32 mode;
        struct sl3516_ce_dev *ce;
        union {
                struct skcipher_engine_alg skcipher;
        } alg;
        unsigned long stat_req;
        unsigned long stat_fb;
        unsigned long stat_bytes;
};

int sl3516_ce_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
                         unsigned int keylen);
int sl3516_ce_cipher_init(struct crypto_tfm *tfm);
void sl3516_ce_cipher_exit(struct crypto_tfm *tfm);
int sl3516_ce_skdecrypt(struct skcipher_request *areq);
int sl3516_ce_skencrypt(struct skcipher_request *areq);

int sl3516_ce_run_task(struct sl3516_ce_dev *ce,
                       struct sl3516_ce_cipher_req_ctx *rctx, const char *name);

int sl3516_ce_rng_register(struct sl3516_ce_dev *ce);
void sl3516_ce_rng_unregister(struct sl3516_ce_dev *ce);
int sl3516_ce_handle_cipher_request(struct crypto_engine *engine, void *areq);