xref: /linux/drivers/crypto/stm32/stm32-cryp.c (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800)

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) STMicroelectronics SA 2017
 * Author: Fabien Dessenne <fabien.dessenne@st.com>
 * Ux500 support taken from snippets in the old Ux500 cryp driver
 */

#include <crypto/aes.h>
#include <crypto/engine.h>
#include <crypto/internal/aead.h>
#include <crypto/internal/des.h>
#include <crypto/internal/skcipher.h>
#include <crypto/scatterwalk.h>
#include <linux/bottom_half.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/err.h>
#include <linux/iopoll.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>
#include <linux/string.h>

#define DRIVER_NAME             "stm32-cryp"

/* Bit [0] encrypt / decrypt */
#define FLG_ENCRYPT             BIT(0)
/* Bit [8..1] algo & operation mode */
#define FLG_AES                 BIT(1)
#define FLG_DES                 BIT(2)
#define FLG_TDES                BIT(3)
#define FLG_ECB                 BIT(4)
#define FLG_CBC                 BIT(5)
#define FLG_CTR                 BIT(6)
#define FLG_GCM                 BIT(7)
#define FLG_CCM                 BIT(8)
/* Mode mask = bits [15..0] */
#define FLG_MODE_MASK           GENMASK(15, 0)
/* Bit [31..16] status  */
#define FLG_IN_OUT_DMA          BIT(16)
#define FLG_HEADER_DMA          BIT(17)

/* Registers */
#define CRYP_CR                 0x00000000
#define CRYP_SR                 0x00000004
#define CRYP_DIN                0x00000008
#define CRYP_DOUT               0x0000000C
#define CRYP_DMACR              0x00000010
#define CRYP_IMSCR              0x00000014
#define CRYP_RISR               0x00000018
#define CRYP_MISR               0x0000001C
#define CRYP_K0LR               0x00000020
#define CRYP_K0RR               0x00000024
#define CRYP_K1LR               0x00000028
#define CRYP_K1RR               0x0000002C
#define CRYP_K2LR               0x00000030
#define CRYP_K2RR               0x00000034
#define CRYP_K3LR               0x00000038
#define CRYP_K3RR               0x0000003C
#define CRYP_IV0LR              0x00000040
#define CRYP_IV0RR              0x00000044
#define CRYP_IV1LR              0x00000048
#define CRYP_IV1RR              0x0000004C
#define CRYP_CSGCMCCM0R         0x00000050
#define CRYP_CSGCM0R            0x00000070

#define UX500_CRYP_CR		0x00000000
#define UX500_CRYP_SR		0x00000004
#define UX500_CRYP_DIN		0x00000008
#define UX500_CRYP_DINSIZE	0x0000000C
#define UX500_CRYP_DOUT		0x00000010
#define UX500_CRYP_DOUSIZE	0x00000014
#define UX500_CRYP_DMACR	0x00000018
#define UX500_CRYP_IMSC		0x0000001C
#define UX500_CRYP_RIS		0x00000020
#define UX500_CRYP_MIS		0x00000024
#define UX500_CRYP_K1L		0x00000028
#define UX500_CRYP_K1R		0x0000002C
#define UX500_CRYP_K2L		0x00000030
#define UX500_CRYP_K2R		0x00000034
#define UX500_CRYP_K3L		0x00000038
#define UX500_CRYP_K3R		0x0000003C
#define UX500_CRYP_K4L		0x00000040
#define UX500_CRYP_K4R		0x00000044
#define UX500_CRYP_IV0L		0x00000048
#define UX500_CRYP_IV0R		0x0000004C
#define UX500_CRYP_IV1L		0x00000050
#define UX500_CRYP_IV1R		0x00000054

/* Registers values */
#define CR_DEC_NOT_ENC          0x00000004
#define CR_TDES_ECB             0x00000000
#define CR_TDES_CBC             0x00000008
#define CR_DES_ECB              0x00000010
#define CR_DES_CBC              0x00000018
#define CR_AES_ECB              0x00000020
#define CR_AES_CBC              0x00000028
#define CR_AES_CTR              0x00000030
#define CR_AES_KP               0x00000038 /* Not on Ux500 */
#define CR_AES_XTS              0x00000038 /* Only on Ux500 */
#define CR_AES_GCM              0x00080000
#define CR_AES_CCM              0x00080008
#define CR_AES_UNKNOWN          0xFFFFFFFF
#define CR_ALGO_MASK            0x00080038
#define CR_DATA32               0x00000000
#define CR_DATA16               0x00000040
#define CR_DATA8                0x00000080
#define CR_DATA1                0x000000C0
#define CR_KEY128               0x00000000
#define CR_KEY192               0x00000100
#define CR_KEY256               0x00000200
#define CR_KEYRDEN              0x00000400 /* Only on Ux500 */
#define CR_KSE                  0x00000800 /* Only on Ux500 */
#define CR_FFLUSH               0x00004000
#define CR_CRYPEN               0x00008000
#define CR_PH_INIT              0x00000000
#define CR_PH_HEADER            0x00010000
#define CR_PH_PAYLOAD           0x00020000
#define CR_PH_FINAL             0x00030000
#define CR_PH_MASK              0x00030000
#define CR_NBPBL_SHIFT          20

#define SR_IFNF                 BIT(1)
#define SR_OFNE                 BIT(2)
#define SR_BUSY                 BIT(8)

#define DMACR_DIEN              BIT(0)
#define DMACR_DOEN              BIT(1)

#define IMSCR_IN                BIT(0)
#define IMSCR_OUT               BIT(1)

#define MISR_IN                 BIT(0)
#define MISR_OUT                BIT(1)

/* Misc */
#define AES_BLOCK_32            (AES_BLOCK_SIZE / sizeof(u32))
#define GCM_CTR_INIT            2
#define CRYP_AUTOSUSPEND_DELAY  50

#define CRYP_DMA_BURST_REG      4

enum stm32_dma_mode {
	NO_DMA,
	DMA_PLAIN_SG,
	DMA_NEED_SG_TRUNC
};

struct stm32_cryp_caps {
	bool			aeads_support;
	bool			linear_aes_key;
	bool			kp_mode;
	bool			iv_protection;
	bool			swap_final;
	bool			padding_wa;
	u32			cr;
	u32			sr;
	u32			din;
	u32			dout;
	u32			dmacr;
	u32			imsc;
	u32			mis;
	u32			k1l;
	u32			k1r;
	u32			k3r;
	u32			iv0l;
	u32			iv0r;
	u32			iv1l;
	u32			iv1r;
};

struct stm32_cryp_ctx {
	struct stm32_cryp       *cryp;
	int                     keylen;
	__be32                  key[AES_KEYSIZE_256 / sizeof(u32)];
	unsigned long           flags;
};

struct stm32_cryp_reqctx {
	unsigned long mode;
};

struct stm32_cryp {
	struct list_head        list;
	struct device           *dev;
	void __iomem            *regs;
	phys_addr_t             phys_base;
	struct clk              *clk;
	unsigned long           flags;
	u32                     irq_status;
	const struct stm32_cryp_caps *caps;
	struct stm32_cryp_ctx   *ctx;

	struct crypto_engine    *engine;

	struct skcipher_request *req;
	struct aead_request     *areq;

	size_t                  authsize;
	size_t                  hw_blocksize;

	size_t                  payload_in;
	size_t                  header_in;
	size_t                  payload_out;

	/* DMA process fields */
	struct scatterlist      *in_sg;
	struct scatterlist      *header_sg;
	struct scatterlist      *out_sg;
	size_t                  in_sg_len;
	size_t                  header_sg_len;
	size_t                  out_sg_len;
	struct completion	dma_completion;

	struct dma_chan         *dma_lch_in;
	struct dma_chan         *dma_lch_out;
	enum stm32_dma_mode     dma_mode;

	/* IT process fields */
	struct scatter_walk     in_walk;
	struct scatter_walk     out_walk;

	__be32                  last_ctr[4];
	u32                     gcm_ctr;
};

struct stm32_cryp_list {
	struct list_head        dev_list;
	spinlock_t              lock; /* protect dev_list */
};

static struct stm32_cryp_list cryp_list = {
	.dev_list = LIST_HEAD_INIT(cryp_list.dev_list),
	.lock     = __SPIN_LOCK_UNLOCKED(cryp_list.lock),
};

static inline bool is_aes(struct stm32_cryp *cryp)
{
	return cryp->flags & FLG_AES;
}

static inline bool is_des(struct stm32_cryp *cryp)
{
	return cryp->flags & FLG_DES;
}

static inline bool is_tdes(struct stm32_cryp *cryp)
{
	return cryp->flags & FLG_TDES;
}

static inline bool is_ecb(struct stm32_cryp *cryp)
{
	return cryp->flags & FLG_ECB;
}

static inline bool is_cbc(struct stm32_cryp *cryp)
{
	return cryp->flags & FLG_CBC;
}

static inline bool is_ctr(struct stm32_cryp *cryp)
{
	return cryp->flags & FLG_CTR;
}

static inline bool is_gcm(struct stm32_cryp *cryp)
{
	return cryp->flags & FLG_GCM;
}

static inline bool is_ccm(struct stm32_cryp *cryp)
{
	return cryp->flags & FLG_CCM;
}

static inline bool is_encrypt(struct stm32_cryp *cryp)
{
	return cryp->flags & FLG_ENCRYPT;
}

static inline bool is_decrypt(struct stm32_cryp *cryp)
{
	return !is_encrypt(cryp);
}

static inline u32 stm32_cryp_read(struct stm32_cryp *cryp, u32 ofst)
{
	return readl_relaxed(cryp->regs + ofst);
}

static inline void stm32_cryp_write(struct stm32_cryp *cryp, u32 ofst, u32 val)
{
	writel_relaxed(val, cryp->regs + ofst);
}

static inline int stm32_cryp_wait_busy(struct stm32_cryp *cryp)
{
	u32 status;

	return readl_relaxed_poll_timeout(cryp->regs + cryp->caps->sr, status,
			!(status & SR_BUSY), 10, 100000);
}

static inline void stm32_cryp_enable(struct stm32_cryp *cryp)
{
	writel_relaxed(readl_relaxed(cryp->regs + cryp->caps->cr) | CR_CRYPEN,
		       cryp->regs + cryp->caps->cr);
}

static inline int stm32_cryp_wait_enable(struct stm32_cryp *cryp)
{
	u32 status;

	return readl_relaxed_poll_timeout(cryp->regs + cryp->caps->cr, status,
			!(status & CR_CRYPEN), 10, 100000);
}

static inline int stm32_cryp_wait_input(struct stm32_cryp *cryp)
{
	u32 status;

	return readl_relaxed_poll_timeout_atomic(cryp->regs + cryp->caps->sr, status,
			status & SR_IFNF, 1, 10);
}

static inline int stm32_cryp_wait_output(struct stm32_cryp *cryp)
{
	u32 status;

	return readl_relaxed_poll_timeout_atomic(cryp->regs + cryp->caps->sr, status,
			status & SR_OFNE, 1, 10);
}

static inline void stm32_cryp_key_read_enable(struct stm32_cryp *cryp)
{
	writel_relaxed(readl_relaxed(cryp->regs + cryp->caps->cr) | CR_KEYRDEN,
		       cryp->regs + cryp->caps->cr);
}

static inline void stm32_cryp_key_read_disable(struct stm32_cryp *cryp)
{
	writel_relaxed(readl_relaxed(cryp->regs + cryp->caps->cr) & ~CR_KEYRDEN,
		       cryp->regs + cryp->caps->cr);
}

static void stm32_cryp_irq_read_data(struct stm32_cryp *cryp);
static void stm32_cryp_irq_write_data(struct stm32_cryp *cryp);
static void stm32_cryp_irq_write_gcmccm_header(struct stm32_cryp *cryp);
static int stm32_cryp_read_auth_tag(struct stm32_cryp *cryp);
static void stm32_cryp_finish_req(struct stm32_cryp *cryp, int err);
static int stm32_cryp_dma_start(struct stm32_cryp *cryp);
static int stm32_cryp_it_start(struct stm32_cryp *cryp);

static struct stm32_cryp *stm32_cryp_find_dev(struct stm32_cryp_ctx *ctx)
{
	struct stm32_cryp *tmp, *cryp = NULL;

	spin_lock_bh(&cryp_list.lock);
	if (!ctx->cryp) {
		list_for_each_entry(tmp, &cryp_list.dev_list, list) {
			cryp = tmp;
			break;
		}
		ctx->cryp = cryp;
	} else {
		cryp = ctx->cryp;
	}

	spin_unlock_bh(&cryp_list.lock);

	return cryp;
}

static void stm32_cryp_hw_write_iv(struct stm32_cryp *cryp, __be32 *iv)
{
	if (!iv)
		return;

	stm32_cryp_write(cryp, cryp->caps->iv0l, be32_to_cpu(*iv++));
	stm32_cryp_write(cryp, cryp->caps->iv0r, be32_to_cpu(*iv++));

	if (is_aes(cryp)) {
		stm32_cryp_write(cryp, cryp->caps->iv1l, be32_to_cpu(*iv++));
		stm32_cryp_write(cryp, cryp->caps->iv1r, be32_to_cpu(*iv++));
	}
}

static void stm32_cryp_get_iv(struct stm32_cryp *cryp)
{
	struct skcipher_request *req = cryp->req;
	__be32 *tmp = (void *)req->iv;

	if (!tmp)
		return;

	if (cryp->caps->iv_protection)
		stm32_cryp_key_read_enable(cryp);

	*tmp++ = cpu_to_be32(stm32_cryp_read(cryp, cryp->caps->iv0l));
	*tmp++ = cpu_to_be32(stm32_cryp_read(cryp, cryp->caps->iv0r));

	if (is_aes(cryp)) {
		*tmp++ = cpu_to_be32(stm32_cryp_read(cryp, cryp->caps->iv1l));
		*tmp++ = cpu_to_be32(stm32_cryp_read(cryp, cryp->caps->iv1r));
	}

	if (cryp->caps->iv_protection)
		stm32_cryp_key_read_disable(cryp);
}

/**
 * ux500_swap_bits_in_byte() - mirror the bits in a byte
 * @b: the byte to be mirrored
 *
 * The bits are swapped the following way:
 *  Byte b include bits 0-7, nibble 1 (n1) include bits 0-3 and
 *  nibble 2 (n2) bits 4-7.
 *
 *  Nibble 1 (n1):
 *  (The "old" (moved) bit is replaced with a zero)
 *  1. Move bit 6 and 7, 4 positions to the left.
 *  2. Move bit 3 and 5, 2 positions to the left.
 *  3. Move bit 1-4, 1 position to the left.
 *
 *  Nibble 2 (n2):
 *  1. Move bit 0 and 1, 4 positions to the right.
 *  2. Move bit 2 and 4, 2 positions to the right.
 *  3. Move bit 3-6, 1 position to the right.
 *
 *  Combine the two nibbles to a complete and swapped byte.
 */
static inline u8 ux500_swap_bits_in_byte(u8 b)
{
#define R_SHIFT_4_MASK  0xc0 /* Bits 6 and 7, right shift 4 */
#define R_SHIFT_2_MASK  0x28 /* (After right shift 4) Bits 3 and 5,
				  right shift 2 */
#define R_SHIFT_1_MASK  0x1e /* (After right shift 2) Bits 1-4,
				  right shift 1 */
#define L_SHIFT_4_MASK  0x03 /* Bits 0 and 1, left shift 4 */
#define L_SHIFT_2_MASK  0x14 /* (After left shift 4) Bits 2 and 4,
				  left shift 2 */
#define L_SHIFT_1_MASK  0x78 /* (After left shift 1) Bits 3-6,
				  left shift 1 */

	u8 n1;
	u8 n2;

	/* Swap most significant nibble */
	/* Right shift 4, bits 6 and 7 */
	n1 = ((b  & R_SHIFT_4_MASK) >> 4) | (b  & ~(R_SHIFT_4_MASK >> 4));
	/* Right shift 2, bits 3 and 5 */
	n1 = ((n1 & R_SHIFT_2_MASK) >> 2) | (n1 & ~(R_SHIFT_2_MASK >> 2));
	/* Right shift 1, bits 1-4 */
	n1 = (n1  & R_SHIFT_1_MASK) >> 1;

	/* Swap least significant nibble */
	/* Left shift 4, bits 0 and 1 */
	n2 = ((b  & L_SHIFT_4_MASK) << 4) | (b  & ~(L_SHIFT_4_MASK << 4));
	/* Left shift 2, bits 2 and 4 */
	n2 = ((n2 & L_SHIFT_2_MASK) << 2) | (n2 & ~(L_SHIFT_2_MASK << 2));
	/* Left shift 1, bits 3-6 */
	n2 = (n2  & L_SHIFT_1_MASK) << 1;

	return n1 | n2;
}

/**
 * ux500_swizzle_key() - Shuffle around words and bits in the AES key
 * @in: key to swizzle
 * @out: swizzled key
 * @len: length of key, in bytes
 *
 * This "key swizzling procedure" is described in the examples in the
 * DB8500 design specification. There is no real description of why
 * the bits have been arranged like this in the hardware.
 */
static inline void ux500_swizzle_key(const u8 *in, u8 *out, u32 len)
{
	int i = 0;
	int bpw = sizeof(u32);
	int j;
	int index = 0;

	j = len - bpw;
	while (j >= 0) {
		for (i = 0; i < bpw; i++) {
			index = len - j - bpw + i;
			out[j + i] =
				ux500_swap_bits_in_byte(in[index]);
		}
		j -= bpw;
	}
}

static void stm32_cryp_hw_write_key(struct stm32_cryp *c)
{
	unsigned int i;
	int r_id;

	if (is_des(c)) {
		stm32_cryp_write(c, c->caps->k1l, be32_to_cpu(c->ctx->key[0]));
		stm32_cryp_write(c, c->caps->k1r, be32_to_cpu(c->ctx->key[1]));
		return;
	}

	/*
	 * On the Ux500 the AES key is considered as a single bit sequence
	 * of 128, 192 or 256 bits length. It is written linearly into the
	 * registers from K1L and down, and need to be processed to become
	 * a proper big-endian bit sequence.
	 */
	if (is_aes(c) && c->caps->linear_aes_key) {
		u32 tmpkey[8];

		ux500_swizzle_key((u8 *)c->ctx->key,
				  (u8 *)tmpkey, c->ctx->keylen);

		r_id = c->caps->k1l;
		for (i = 0; i < c->ctx->keylen / sizeof(u32); i++, r_id += 4)
			stm32_cryp_write(c, r_id, tmpkey[i]);

		return;
	}

	r_id = c->caps->k3r;
	for (i = c->ctx->keylen / sizeof(u32); i > 0; i--, r_id -= 4)
		stm32_cryp_write(c, r_id, be32_to_cpu(c->ctx->key[i - 1]));
}

static u32 stm32_cryp_get_hw_mode(struct stm32_cryp *cryp)
{
	if (is_aes(cryp) && is_ecb(cryp))
		return CR_AES_ECB;

	if (is_aes(cryp) && is_cbc(cryp))
		return CR_AES_CBC;

	if (is_aes(cryp) && is_ctr(cryp))
		return CR_AES_CTR;

	if (is_aes(cryp) && is_gcm(cryp))
		return CR_AES_GCM;

	if (is_aes(cryp) && is_ccm(cryp))
		return CR_AES_CCM;

	if (is_des(cryp) && is_ecb(cryp))
		return CR_DES_ECB;

	if (is_des(cryp) && is_cbc(cryp))
		return CR_DES_CBC;

	if (is_tdes(cryp) && is_ecb(cryp))
		return CR_TDES_ECB;

	if (is_tdes(cryp) && is_cbc(cryp))
		return CR_TDES_CBC;

	dev_err(cryp->dev, "Unknown mode\n");
	return CR_AES_UNKNOWN;
}

static unsigned int stm32_cryp_get_input_text_len(struct stm32_cryp *cryp)
{
	return is_encrypt(cryp) ? cryp->areq->cryptlen :
				  cryp->areq->cryptlen - cryp->authsize;
}

static int stm32_cryp_gcm_init(struct stm32_cryp *cryp, u32 cfg)
{
	int ret;
	__be32 iv[4];

	/* Phase 1 : init */
	memcpy(iv, cryp->areq->iv, 12);
	iv[3] = cpu_to_be32(GCM_CTR_INIT);
	cryp->gcm_ctr = GCM_CTR_INIT;
	stm32_cryp_hw_write_iv(cryp, iv);

	stm32_cryp_write(cryp, cryp->caps->cr, cfg | CR_PH_INIT | CR_CRYPEN);

	/* Wait for end of processing */
	ret = stm32_cryp_wait_enable(cryp);
	if (ret) {
		dev_err(cryp->dev, "Timeout (gcm init)\n");
		return ret;
	}

	/* Prepare next phase */
	if (cryp->areq->assoclen) {
		cfg |= CR_PH_HEADER;
		stm32_cryp_write(cryp, cryp->caps->cr, cfg);
	} else if (stm32_cryp_get_input_text_len(cryp)) {
		cfg |= CR_PH_PAYLOAD;
		stm32_cryp_write(cryp, cryp->caps->cr, cfg);
	}

	return 0;
}

static void stm32_crypt_gcmccm_end_header(struct stm32_cryp *cryp)
{
	u32 cfg;
	int err;

	/* Check if whole header written */
	if (!cryp->header_in) {
		/* Wait for completion */
		err = stm32_cryp_wait_busy(cryp);
		if (err) {
			dev_err(cryp->dev, "Timeout (gcm/ccm header)\n");
			stm32_cryp_write(cryp, cryp->caps->imsc, 0);
			stm32_cryp_finish_req(cryp, err);
			return;
		}

		if (stm32_cryp_get_input_text_len(cryp)) {
			/* Phase 3 : payload */
			cfg = stm32_cryp_read(cryp, cryp->caps->cr);
			cfg &= ~CR_CRYPEN;
			stm32_cryp_write(cryp, cryp->caps->cr, cfg);

			cfg &= ~CR_PH_MASK;
			cfg |= CR_PH_PAYLOAD | CR_CRYPEN;
			stm32_cryp_write(cryp, cryp->caps->cr, cfg);
		} else {
			/*
			 * Phase 4 : tag.
			 * Nothing to read, nothing to write, caller have to
			 * end request
			 */
		}
	}
}

static void stm32_cryp_write_ccm_first_header(struct stm32_cryp *cryp)
{
	size_t written;
	size_t len;
	u32 alen = cryp->areq->assoclen;
	u32 block[AES_BLOCK_32] = {0};
	u8 *b8 = (u8 *)block;

	if (alen <= 65280) {
		/* Write first u32 of B1 */
		b8[0] = (alen >> 8) & 0xFF;
		b8[1] = alen & 0xFF;
		len = 2;
	} else {
		/* Build the two first u32 of B1 */
		b8[0] = 0xFF;
		b8[1] = 0xFE;
		b8[2] = (alen & 0xFF000000) >> 24;
		b8[3] = (alen & 0x00FF0000) >> 16;
		b8[4] = (alen & 0x0000FF00) >> 8;
		b8[5] = alen & 0x000000FF;
		len = 6;
	}

	written = min_t(size_t, AES_BLOCK_SIZE - len, alen);

	scatterwalk_copychunks((char *)block + len, &cryp->in_walk, written, 0);

	writesl(cryp->regs + cryp->caps->din, block, AES_BLOCK_32);

	cryp->header_in -= written;

	stm32_crypt_gcmccm_end_header(cryp);
}

static int stm32_cryp_ccm_init(struct stm32_cryp *cryp, u32 cfg)
{
	int ret;
	u32 iv_32[AES_BLOCK_32], b0_32[AES_BLOCK_32];
	u8 *iv = (u8 *)iv_32, *b0 = (u8 *)b0_32;
	__be32 *bd;
	u32 *d;
	unsigned int i, textlen;

	/* Phase 1 : init. Firstly set the CTR value to 1 (not 0) */
	memcpy(iv, cryp->areq->iv, AES_BLOCK_SIZE);
	memset(iv + AES_BLOCK_SIZE - 1 - iv[0], 0, iv[0] + 1);
	iv[AES_BLOCK_SIZE - 1] = 1;
	stm32_cryp_hw_write_iv(cryp, (__be32 *)iv);

	/* Build B0 */
	memcpy(b0, iv, AES_BLOCK_SIZE);

	b0[0] |= (8 * ((cryp->authsize - 2) / 2));

	if (cryp->areq->assoclen)
		b0[0] |= 0x40;

	textlen = stm32_cryp_get_input_text_len(cryp);

	b0[AES_BLOCK_SIZE - 2] = textlen >> 8;
	b0[AES_BLOCK_SIZE - 1] = textlen & 0xFF;

	/* Enable HW */
	stm32_cryp_write(cryp, cryp->caps->cr, cfg | CR_PH_INIT | CR_CRYPEN);

	/* Write B0 */
	d = (u32 *)b0;
	bd = (__be32 *)b0;

	for (i = 0; i < AES_BLOCK_32; i++) {
		u32 xd = d[i];

		if (!cryp->caps->padding_wa)
			xd = be32_to_cpu(bd[i]);
		stm32_cryp_write(cryp, cryp->caps->din, xd);
	}

	/* Wait for end of processing */
	ret = stm32_cryp_wait_enable(cryp);
	if (ret) {
		dev_err(cryp->dev, "Timeout (ccm init)\n");
		return ret;
	}

	/* Prepare next phase */
	if (cryp->areq->assoclen) {
		cfg |= CR_PH_HEADER | CR_CRYPEN;
		stm32_cryp_write(cryp, cryp->caps->cr, cfg);

		/* Write first (special) block (may move to next phase [payload]) */
		stm32_cryp_write_ccm_first_header(cryp);
	} else if (stm32_cryp_get_input_text_len(cryp)) {
		cfg |= CR_PH_PAYLOAD;
		stm32_cryp_write(cryp, cryp->caps->cr, cfg);
	}

	return 0;
}

static int stm32_cryp_hw_init(struct stm32_cryp *cryp)
{
	int ret;
	u32 cfg, hw_mode;

	pm_runtime_get_sync(cryp->dev);

	/* Disable interrupt */
	stm32_cryp_write(cryp, cryp->caps->imsc, 0);

	/* Set configuration */
	cfg = CR_DATA8 | CR_FFLUSH;

	switch (cryp->ctx->keylen) {
	case AES_KEYSIZE_128:
		cfg |= CR_KEY128;
		break;

	case AES_KEYSIZE_192:
		cfg |= CR_KEY192;
		break;

	default:
	case AES_KEYSIZE_256:
		cfg |= CR_KEY256;
		break;
	}

	hw_mode = stm32_cryp_get_hw_mode(cryp);
	if (hw_mode == CR_AES_UNKNOWN)
		return -EINVAL;

	/* AES ECB/CBC decrypt: run key preparation first */
	if (is_decrypt(cryp) &&
	    ((hw_mode == CR_AES_ECB) || (hw_mode == CR_AES_CBC))) {
		/* Configure in key preparation mode */
		if (cryp->caps->kp_mode)
			stm32_cryp_write(cryp, cryp->caps->cr,
				cfg | CR_AES_KP);
		else
			stm32_cryp_write(cryp,
				cryp->caps->cr, cfg | CR_AES_ECB | CR_KSE);

		/* Set key only after full configuration done */
		stm32_cryp_hw_write_key(cryp);

		/* Start prepare key */
		stm32_cryp_enable(cryp);
		/* Wait for end of processing */
		ret = stm32_cryp_wait_busy(cryp);
		if (ret) {
			dev_err(cryp->dev, "Timeout (key preparation)\n");
			return ret;
		}

		cfg |= hw_mode | CR_DEC_NOT_ENC;

		/* Apply updated config (Decrypt + algo) and flush */
		stm32_cryp_write(cryp, cryp->caps->cr, cfg);
	} else {
		cfg |= hw_mode;
		if (is_decrypt(cryp))
			cfg |= CR_DEC_NOT_ENC;

		/* Apply config and flush */
		stm32_cryp_write(cryp, cryp->caps->cr, cfg);

		/* Set key only after configuration done */
		stm32_cryp_hw_write_key(cryp);
	}

	switch (hw_mode) {
	case CR_AES_GCM:
	case CR_AES_CCM:
		/* Phase 1 : init */
		if (hw_mode == CR_AES_CCM)
			ret = stm32_cryp_ccm_init(cryp, cfg);
		else
			ret = stm32_cryp_gcm_init(cryp, cfg);

		if (ret)
			return ret;

		break;

	case CR_DES_CBC:
	case CR_TDES_CBC:
	case CR_AES_CBC:
	case CR_AES_CTR:
		stm32_cryp_hw_write_iv(cryp, (__be32 *)cryp->req->iv);
		break;

	default:
		break;
	}

	/* Enable now */
	stm32_cryp_enable(cryp);

	return 0;
}

static void stm32_cryp_finish_req(struct stm32_cryp *cryp, int err)
{
	if (!err && (is_gcm(cryp) || is_ccm(cryp)))
		/* Phase 4 : output tag */
		err = stm32_cryp_read_auth_tag(cryp);

	if (!err && (!(is_gcm(cryp) || is_ccm(cryp) || is_ecb(cryp))))
		stm32_cryp_get_iv(cryp);

	pm_runtime_mark_last_busy(cryp->dev);
	pm_runtime_put_autosuspend(cryp->dev);

	if (is_gcm(cryp) || is_ccm(cryp))
		crypto_finalize_aead_request(cryp->engine, cryp->areq, err);
	else
		crypto_finalize_skcipher_request(cryp->engine, cryp->req, err);
}

static void stm32_cryp_header_dma_callback(void *param)
{
	struct stm32_cryp *cryp = (struct stm32_cryp *)param;
	int ret;
	u32 reg;

	dma_unmap_sg(cryp->dev, cryp->header_sg, cryp->header_sg_len, DMA_TO_DEVICE);

	reg = stm32_cryp_read(cryp, cryp->caps->dmacr);
	stm32_cryp_write(cryp, cryp->caps->dmacr, reg & ~(DMACR_DOEN | DMACR_DIEN));

	kfree(cryp->header_sg);

	reg = stm32_cryp_read(cryp, cryp->caps->cr);

	if (cryp->header_in) {
		stm32_cryp_write(cryp, cryp->caps->cr, reg | CR_CRYPEN);

		ret = stm32_cryp_wait_input(cryp);
		if (ret) {
			dev_err(cryp->dev, "input header ready timeout after dma\n");
			stm32_cryp_finish_req(cryp, ret);
			return;
		}
		stm32_cryp_irq_write_gcmccm_header(cryp);
		WARN_ON(cryp->header_in);
	}

	if (stm32_cryp_get_input_text_len(cryp)) {
		/* Phase 3 : payload */
		reg = stm32_cryp_read(cryp, cryp->caps->cr);
		stm32_cryp_write(cryp, cryp->caps->cr, reg & ~CR_CRYPEN);

		reg &= ~CR_PH_MASK;
		reg |= CR_PH_PAYLOAD | CR_CRYPEN;
		stm32_cryp_write(cryp, cryp->caps->cr, reg);

		if (cryp->flags & FLG_IN_OUT_DMA) {
			ret = stm32_cryp_dma_start(cryp);
			if (ret)
				stm32_cryp_finish_req(cryp, ret);
		} else {
			stm32_cryp_it_start(cryp);
		}
	} else {
		/*
		 * Phase 4 : tag.
		 * Nothing to read, nothing to write => end request
		 */
		stm32_cryp_finish_req(cryp, 0);
	}
}

static void stm32_cryp_dma_callback(void *param)
{
	struct stm32_cryp *cryp = (struct stm32_cryp *)param;
	int ret;
	u32 reg;

	complete(&cryp->dma_completion); /* completion to indicate no timeout */

	dma_sync_sg_for_device(cryp->dev, cryp->out_sg, cryp->out_sg_len, DMA_FROM_DEVICE);

	if (cryp->in_sg != cryp->out_sg)
		dma_unmap_sg(cryp->dev, cryp->in_sg, cryp->in_sg_len, DMA_TO_DEVICE);

	dma_unmap_sg(cryp->dev, cryp->out_sg, cryp->out_sg_len, DMA_FROM_DEVICE);

	reg = stm32_cryp_read(cryp, cryp->caps->dmacr);
	stm32_cryp_write(cryp, cryp->caps->dmacr, reg & ~(DMACR_DOEN | DMACR_DIEN));

	reg = stm32_cryp_read(cryp, cryp->caps->cr);

	if (is_gcm(cryp) || is_ccm(cryp)) {
		kfree(cryp->in_sg);
		kfree(cryp->out_sg);
	} else {
		if (cryp->in_sg != cryp->req->src)
			kfree(cryp->in_sg);
		if (cryp->out_sg != cryp->req->dst)
			kfree(cryp->out_sg);
	}

	if (cryp->payload_in) {
		stm32_cryp_write(cryp, cryp->caps->cr, reg | CR_CRYPEN);

		ret = stm32_cryp_wait_input(cryp);
		if (ret) {
			dev_err(cryp->dev, "input ready timeout after dma\n");
			stm32_cryp_finish_req(cryp, ret);
			return;
		}
		stm32_cryp_irq_write_data(cryp);

		ret = stm32_cryp_wait_output(cryp);
		if (ret) {
			dev_err(cryp->dev, "output ready timeout after dma\n");
			stm32_cryp_finish_req(cryp, ret);
			return;
		}
		stm32_cryp_irq_read_data(cryp);
	}

	stm32_cryp_finish_req(cryp, 0);
}

static int stm32_cryp_header_dma_start(struct stm32_cryp *cryp)
{
	int ret;
	struct dma_async_tx_descriptor *tx_in;
	u32 reg;
	size_t align_size;

	ret = dma_map_sg(cryp->dev, cryp->header_sg, cryp->header_sg_len, DMA_TO_DEVICE);
	if (!ret) {
		dev_err(cryp->dev, "dma_map_sg() error\n");
		return -ENOMEM;
	}

	dma_sync_sg_for_device(cryp->dev, cryp->header_sg, cryp->header_sg_len, DMA_TO_DEVICE);

	tx_in = dmaengine_prep_slave_sg(cryp->dma_lch_in, cryp->header_sg, cryp->header_sg_len,
					DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
	if (!tx_in) {
		dev_err(cryp->dev, "IN prep_slave_sg() failed\n");
		return -EINVAL;
	}

	tx_in->callback_param = cryp;
	tx_in->callback = stm32_cryp_header_dma_callback;

	/* Advance scatterwalk to not DMA'ed data */
	align_size = ALIGN_DOWN(cryp->header_in, cryp->hw_blocksize);
	scatterwalk_copychunks(NULL, &cryp->in_walk, align_size, 2);
	cryp->header_in -= align_size;

	ret = dma_submit_error(dmaengine_submit(tx_in));
	if (ret < 0) {
		dev_err(cryp->dev, "DMA in submit failed\n");
		return ret;
	}
	dma_async_issue_pending(cryp->dma_lch_in);

	reg = stm32_cryp_read(cryp, cryp->caps->dmacr);
	stm32_cryp_write(cryp, cryp->caps->dmacr, reg | DMACR_DIEN);

	return 0;
}

static int stm32_cryp_dma_start(struct stm32_cryp *cryp)
{
	int ret;
	size_t align_size;
	struct dma_async_tx_descriptor *tx_in, *tx_out;
	u32 reg;

	if (cryp->in_sg != cryp->out_sg) {
		ret = dma_map_sg(cryp->dev, cryp->in_sg, cryp->in_sg_len, DMA_TO_DEVICE);
		if (!ret) {
			dev_err(cryp->dev, "dma_map_sg() error\n");
			return -ENOMEM;
		}
	}

	ret = dma_map_sg(cryp->dev, cryp->out_sg, cryp->out_sg_len, DMA_FROM_DEVICE);
	if (!ret) {
		dev_err(cryp->dev, "dma_map_sg() error\n");
		return -ENOMEM;
	}

	dma_sync_sg_for_device(cryp->dev, cryp->in_sg, cryp->in_sg_len, DMA_TO_DEVICE);

	tx_in = dmaengine_prep_slave_sg(cryp->dma_lch_in, cryp->in_sg, cryp->in_sg_len,
					DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
	if (!tx_in) {
		dev_err(cryp->dev, "IN prep_slave_sg() failed\n");
		return -EINVAL;
	}

	/* No callback necessary */
	tx_in->callback_param = cryp;
	tx_in->callback = NULL;

	tx_out = dmaengine_prep_slave_sg(cryp->dma_lch_out, cryp->out_sg, cryp->out_sg_len,
					 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
	if (!tx_out) {
		dev_err(cryp->dev, "OUT prep_slave_sg() failed\n");
		return -EINVAL;
	}

	reinit_completion(&cryp->dma_completion);
	tx_out->callback = stm32_cryp_dma_callback;
	tx_out->callback_param = cryp;

	/* Advance scatterwalk to not DMA'ed data */
	align_size = ALIGN_DOWN(cryp->payload_in, cryp->hw_blocksize);
	scatterwalk_copychunks(NULL, &cryp->in_walk, align_size, 2);
	cryp->payload_in -= align_size;

	ret = dma_submit_error(dmaengine_submit(tx_in));
	if (ret < 0) {
		dev_err(cryp->dev, "DMA in submit failed\n");
		return ret;
	}
	dma_async_issue_pending(cryp->dma_lch_in);

	/* Advance scatterwalk to not DMA'ed data */
	scatterwalk_copychunks(NULL, &cryp->out_walk, align_size, 2);
	cryp->payload_out -= align_size;
	ret = dma_submit_error(dmaengine_submit(tx_out));
	if (ret < 0) {
		dev_err(cryp->dev, "DMA out submit failed\n");
		return ret;
	}
	dma_async_issue_pending(cryp->dma_lch_out);

	reg = stm32_cryp_read(cryp, cryp->caps->dmacr);
	stm32_cryp_write(cryp, cryp->caps->dmacr, reg | DMACR_DOEN | DMACR_DIEN);

	if (!wait_for_completion_timeout(&cryp->dma_completion, msecs_to_jiffies(1000))) {
		dev_err(cryp->dev, "DMA out timed out\n");
		dmaengine_terminate_sync(cryp->dma_lch_out);
		return -ETIMEDOUT;
	}

	return 0;
}

static int stm32_cryp_it_start(struct stm32_cryp *cryp)
{
	/* Enable interrupt and let the IRQ handler do everything */
	stm32_cryp_write(cryp, cryp->caps->imsc, IMSCR_IN | IMSCR_OUT);

	return 0;
}

static int stm32_cryp_cipher_one_req(struct crypto_engine *engine, void *areq);

static int stm32_cryp_init_tfm(struct crypto_skcipher *tfm)
{
	crypto_skcipher_set_reqsize(tfm, sizeof(struct stm32_cryp_reqctx));

	return 0;
}

static int stm32_cryp_aead_one_req(struct crypto_engine *engine, void *areq);

static int stm32_cryp_aes_aead_init(struct crypto_aead *tfm)
{
	crypto_aead_set_reqsize(tfm, sizeof(struct stm32_cryp_reqctx));

	return 0;
}

static int stm32_cryp_crypt(struct skcipher_request *req, unsigned long mode)
{
	struct stm32_cryp_ctx *ctx = crypto_skcipher_ctx(
			crypto_skcipher_reqtfm(req));
	struct stm32_cryp_reqctx *rctx = skcipher_request_ctx(req);
	struct stm32_cryp *cryp = stm32_cryp_find_dev(ctx);

	if (!cryp)
		return -ENODEV;

	rctx->mode = mode;

	return crypto_transfer_skcipher_request_to_engine(cryp->engine, req);
}

static int stm32_cryp_aead_crypt(struct aead_request *req, unsigned long mode)
{
	struct stm32_cryp_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
	struct stm32_cryp_reqctx *rctx = aead_request_ctx(req);
	struct stm32_cryp *cryp = stm32_cryp_find_dev(ctx);

	if (!cryp)
		return -ENODEV;

	rctx->mode = mode;

	return crypto_transfer_aead_request_to_engine(cryp->engine, req);
}

static int stm32_cryp_setkey(struct crypto_skcipher *tfm, const u8 *key,
			     unsigned int keylen)
{
	struct stm32_cryp_ctx *ctx = crypto_skcipher_ctx(tfm);

	memcpy(ctx->key, key, keylen);
	ctx->keylen = keylen;

	return 0;
}

static int stm32_cryp_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
				 unsigned int keylen)
{
	if (keylen != AES_KEYSIZE_128 && keylen != AES_KEYSIZE_192 &&
	    keylen != AES_KEYSIZE_256)
		return -EINVAL;
	else
		return stm32_cryp_setkey(tfm, key, keylen);
}

static int stm32_cryp_des_setkey(struct crypto_skcipher *tfm, const u8 *key,
				 unsigned int keylen)
{
	return verify_skcipher_des_key(tfm, key) ?:
	       stm32_cryp_setkey(tfm, key, keylen);
}

static int stm32_cryp_tdes_setkey(struct crypto_skcipher *tfm, const u8 *key,
				  unsigned int keylen)
{
	return verify_skcipher_des3_key(tfm, key) ?:
	       stm32_cryp_setkey(tfm, key, keylen);
}

static int stm32_cryp_aes_aead_setkey(struct crypto_aead *tfm, const u8 *key,
				      unsigned int keylen)
{
	struct stm32_cryp_ctx *ctx = crypto_aead_ctx(tfm);

	if (keylen != AES_KEYSIZE_128 && keylen != AES_KEYSIZE_192 &&
	    keylen != AES_KEYSIZE_256)
		return -EINVAL;

	memcpy(ctx->key, key, keylen);
	ctx->keylen = keylen;

	return 0;
}

static int stm32_cryp_aes_gcm_setauthsize(struct crypto_aead *tfm,
					  unsigned int authsize)
{
	switch (authsize) {
	case 4:
	case 8:
	case 12:
	case 13:
	case 14:
	case 15:
	case 16:
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static int stm32_cryp_aes_ccm_setauthsize(struct crypto_aead *tfm,
					  unsigned int authsize)
{
	switch (authsize) {
	case 4:
	case 6:
	case 8:
	case 10:
	case 12:
	case 14:
	case 16:
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static int stm32_cryp_aes_ecb_encrypt(struct skcipher_request *req)
{
	if (req->cryptlen % AES_BLOCK_SIZE)
		return -EINVAL;

	if (req->cryptlen == 0)
		return 0;

	return stm32_cryp_crypt(req, FLG_AES | FLG_ECB | FLG_ENCRYPT);
}

static int stm32_cryp_aes_ecb_decrypt(struct skcipher_request *req)
{
	if (req->cryptlen % AES_BLOCK_SIZE)
		return -EINVAL;

	if (req->cryptlen == 0)
		return 0;

	return stm32_cryp_crypt(req, FLG_AES | FLG_ECB);
}

static int stm32_cryp_aes_cbc_encrypt(struct skcipher_request *req)
{
	if (req->cryptlen % AES_BLOCK_SIZE)
		return -EINVAL;

	if (req->cryptlen == 0)
		return 0;

	return stm32_cryp_crypt(req, FLG_AES | FLG_CBC | FLG_ENCRYPT);
}

static int stm32_cryp_aes_cbc_decrypt(struct skcipher_request *req)
{
	if (req->cryptlen % AES_BLOCK_SIZE)
		return -EINVAL;

	if (req->cryptlen == 0)
		return 0;

	return stm32_cryp_crypt(req, FLG_AES | FLG_CBC);
}

static int stm32_cryp_aes_ctr_encrypt(struct skcipher_request *req)
{
	if (req->cryptlen == 0)
		return 0;

	return stm32_cryp_crypt(req, FLG_AES | FLG_CTR | FLG_ENCRYPT);
}

static int stm32_cryp_aes_ctr_decrypt(struct skcipher_request *req)
{
	if (req->cryptlen == 0)
		return 0;

	return stm32_cryp_crypt(req, FLG_AES | FLG_CTR);
}

static int stm32_cryp_aes_gcm_encrypt(struct aead_request *req)
{
	return stm32_cryp_aead_crypt(req, FLG_AES | FLG_GCM | FLG_ENCRYPT);
}

static int stm32_cryp_aes_gcm_decrypt(struct aead_request *req)
{
	return stm32_cryp_aead_crypt(req, FLG_AES | FLG_GCM);
}

static inline int crypto_ccm_check_iv(const u8 *iv)
{
	/* 2 <= L <= 8, so 1 <= L' <= 7. */
	if (iv[0] < 1 || iv[0] > 7)
		return -EINVAL;

	return 0;
}

static int stm32_cryp_aes_ccm_encrypt(struct aead_request *req)
{
	int err;

	err = crypto_ccm_check_iv(req->iv);
	if (err)
		return err;

	return stm32_cryp_aead_crypt(req, FLG_AES | FLG_CCM | FLG_ENCRYPT);
}

static int stm32_cryp_aes_ccm_decrypt(struct aead_request *req)
{
	int err;

	err = crypto_ccm_check_iv(req->iv);
	if (err)
		return err;

	return stm32_cryp_aead_crypt(req, FLG_AES | FLG_CCM);
}

static int stm32_cryp_des_ecb_encrypt(struct skcipher_request *req)
{
	if (req->cryptlen % DES_BLOCK_SIZE)
		return -EINVAL;

	if (req->cryptlen == 0)
		return 0;

	return stm32_cryp_crypt(req, FLG_DES | FLG_ECB | FLG_ENCRYPT);
}

static int stm32_cryp_des_ecb_decrypt(struct skcipher_request *req)
{
	if (req->cryptlen % DES_BLOCK_SIZE)
		return -EINVAL;

	if (req->cryptlen == 0)
		return 0;

	return stm32_cryp_crypt(req, FLG_DES | FLG_ECB);
}

static int stm32_cryp_des_cbc_encrypt(struct skcipher_request *req)
{
	if (req->cryptlen % DES_BLOCK_SIZE)
		return -EINVAL;

	if (req->cryptlen == 0)
		return 0;

	return stm32_cryp_crypt(req, FLG_DES | FLG_CBC | FLG_ENCRYPT);
}

static int stm32_cryp_des_cbc_decrypt(struct skcipher_request *req)
{
	if (req->cryptlen % DES_BLOCK_SIZE)
		return -EINVAL;

	if (req->cryptlen == 0)
		return 0;

	return stm32_cryp_crypt(req, FLG_DES | FLG_CBC);
}

static int stm32_cryp_tdes_ecb_encrypt(struct skcipher_request *req)
{
	if (req->cryptlen % DES_BLOCK_SIZE)
		return -EINVAL;

	if (req->cryptlen == 0)
		return 0;

	return stm32_cryp_crypt(req, FLG_TDES | FLG_ECB | FLG_ENCRYPT);
}

static int stm32_cryp_tdes_ecb_decrypt(struct skcipher_request *req)
{
	if (req->cryptlen % DES_BLOCK_SIZE)
		return -EINVAL;

	if (req->cryptlen == 0)
		return 0;

	return stm32_cryp_crypt(req, FLG_TDES | FLG_ECB);
}

static int stm32_cryp_tdes_cbc_encrypt(struct skcipher_request *req)
{
	if (req->cryptlen % DES_BLOCK_SIZE)
		return -EINVAL;

	if (req->cryptlen == 0)
		return 0;

	return stm32_cryp_crypt(req, FLG_TDES | FLG_CBC | FLG_ENCRYPT);
}

static int stm32_cryp_tdes_cbc_decrypt(struct skcipher_request *req)
{
	if (req->cryptlen % DES_BLOCK_SIZE)
		return -EINVAL;

	if (req->cryptlen == 0)
		return 0;

	return stm32_cryp_crypt(req, FLG_TDES | FLG_CBC);
}

static enum stm32_dma_mode stm32_cryp_dma_check_sg(struct scatterlist *test_sg, size_t len,
						   size_t block_size)
{
	struct scatterlist *sg;
	int i;

	if (len <= 16)
		return NO_DMA; /* Faster */

	for_each_sg(test_sg, sg, sg_nents(test_sg), i) {
		if (!IS_ALIGNED(sg->length, block_size) && !sg_is_last(sg))
			return NO_DMA;

		if (sg->offset % sizeof(u32))
			return NO_DMA;

		if (sg_is_last(sg) && !IS_ALIGNED(sg->length, AES_BLOCK_SIZE))
			return DMA_NEED_SG_TRUNC;
	}

	return DMA_PLAIN_SG;
}

static enum stm32_dma_mode stm32_cryp_dma_check(struct stm32_cryp *cryp, struct scatterlist *in_sg,
						struct scatterlist *out_sg)
{
	enum stm32_dma_mode ret = DMA_PLAIN_SG;

	if (!is_aes(cryp))
		return NO_DMA;

	if (!cryp->dma_lch_in || !cryp->dma_lch_out)
		return NO_DMA;

	ret = stm32_cryp_dma_check_sg(in_sg, cryp->payload_in, AES_BLOCK_SIZE);
	if (ret == NO_DMA)
		return ret;

	ret = stm32_cryp_dma_check_sg(out_sg, cryp->payload_out, AES_BLOCK_SIZE);
	if (ret == NO_DMA)
		return ret;

	/* Check CTR counter overflow */
	if (is_aes(cryp) && is_ctr(cryp)) {
		u32 c;
		__be32 iv3;

		memcpy(&iv3, &cryp->req->iv[3 * sizeof(u32)], sizeof(iv3));
		c = be32_to_cpu(iv3);
		if ((c + cryp->payload_in) < cryp->payload_in)
			return NO_DMA;
	}

	/* Workaround */
	if (is_aes(cryp) && is_ctr(cryp) && ret == DMA_NEED_SG_TRUNC)
		return NO_DMA;

	return ret;
}

static int stm32_cryp_truncate_sg(struct scatterlist **new_sg, size_t *new_sg_len,
				  struct scatterlist *sg, off_t skip, size_t size)
{
	struct scatterlist *cur;
	int alloc_sg_len;

	*new_sg_len = 0;

	if (!sg || !size) {
		*new_sg = NULL;
		return 0;
	}

	alloc_sg_len = sg_nents_for_len(sg, skip + size);
	if (alloc_sg_len < 0)
		return alloc_sg_len;

	/* We allocate to much sg entry, but it is easier */
	*new_sg = kmalloc_array((size_t)alloc_sg_len, sizeof(struct scatterlist), GFP_KERNEL);
	if (!*new_sg)
		return -ENOMEM;

	sg_init_table(*new_sg, (unsigned int)alloc_sg_len);

	cur = *new_sg;
	while (sg && size) {
		unsigned int len = sg->length;
		unsigned int offset = sg->offset;

		if (skip > len) {
			skip -= len;
			sg = sg_next(sg);
			continue;
		}

		if (skip) {
			len -= skip;
			offset += skip;
			skip = 0;
		}

		if (size < len)
			len = size;

		if (len > 0) {
			(*new_sg_len)++;
			size -= len;
			sg_set_page(cur, sg_page(sg), len, offset);
			if (size == 0)
				sg_mark_end(cur);
			cur = sg_next(cur);
		}

		sg = sg_next(sg);
	}

	return 0;
}

static int stm32_cryp_cipher_prepare(struct stm32_cryp *cryp, struct scatterlist *in_sg,
				     struct scatterlist *out_sg)
{
	size_t align_size;
	int ret;

	cryp->dma_mode = stm32_cryp_dma_check(cryp, in_sg, out_sg);

	scatterwalk_start(&cryp->in_walk, in_sg);
	scatterwalk_start(&cryp->out_walk, out_sg);

	if (cryp->dma_mode == NO_DMA) {
		cryp->flags &= ~FLG_IN_OUT_DMA;

		if (is_ctr(cryp))
			memset(cryp->last_ctr, 0, sizeof(cryp->last_ctr));

	} else if (cryp->dma_mode == DMA_NEED_SG_TRUNC) {

		cryp->flags |= FLG_IN_OUT_DMA;

		align_size = ALIGN_DOWN(cryp->payload_in, cryp->hw_blocksize);
		ret = stm32_cryp_truncate_sg(&cryp->in_sg, &cryp->in_sg_len, in_sg, 0, align_size);
		if (ret)
			return ret;

		ret = stm32_cryp_truncate_sg(&cryp->out_sg, &cryp->out_sg_len, out_sg, 0,
					     align_size);
		if (ret) {
			kfree(cryp->in_sg);
			return ret;
		}
	} else {
		cryp->flags |= FLG_IN_OUT_DMA;

		cryp->in_sg = in_sg;
		cryp->out_sg = out_sg;

		ret = sg_nents_for_len(cryp->in_sg, cryp->payload_in);
		if (ret < 0)
			return ret;
		cryp->in_sg_len = (size_t)ret;

		ret = sg_nents_for_len(out_sg, cryp->payload_out);
		if (ret < 0)
			return ret;
		cryp->out_sg_len = (size_t)ret;
	}

	return 0;
}

static int stm32_cryp_aead_prepare(struct stm32_cryp *cryp, struct scatterlist *in_sg,
				   struct scatterlist *out_sg)
{
	size_t align_size;
	off_t skip;
	int ret, ret2;

	cryp->header_sg = NULL;
	cryp->in_sg = NULL;
	cryp->out_sg = NULL;

	if (!cryp->dma_lch_in || !cryp->dma_lch_out) {
		cryp->dma_mode = NO_DMA;
		cryp->flags &= ~(FLG_IN_OUT_DMA | FLG_HEADER_DMA);

		return 0;
	}

	/* CCM hw_init may have advanced in header */
	skip = cryp->areq->assoclen - cryp->header_in;

	align_size = ALIGN_DOWN(cryp->header_in, cryp->hw_blocksize);
	ret = stm32_cryp_truncate_sg(&cryp->header_sg, &cryp->header_sg_len, in_sg, skip,
				     align_size);
	if (ret)
		return ret;

	ret = stm32_cryp_dma_check_sg(cryp->header_sg, align_size, AES_BLOCK_SIZE);
	if (ret == NO_DMA) {
		/* We cannot DMA the header */
		kfree(cryp->header_sg);
		cryp->header_sg = NULL;

		cryp->flags &= ~FLG_HEADER_DMA;
	} else {
		cryp->flags |= FLG_HEADER_DMA;
	}

	/* Now skip all header to be at payload start */
	skip = cryp->areq->assoclen;
	align_size = ALIGN_DOWN(cryp->payload_in, cryp->hw_blocksize);
	ret = stm32_cryp_truncate_sg(&cryp->in_sg, &cryp->in_sg_len, in_sg, skip, align_size);
	if (ret) {
		kfree(cryp->header_sg);
		return ret;
	}

	/* For out buffer align_size is same as in buffer */
	ret = stm32_cryp_truncate_sg(&cryp->out_sg, &cryp->out_sg_len, out_sg, skip, align_size);
	if (ret) {
		kfree(cryp->header_sg);
		kfree(cryp->in_sg);
		return ret;
	}

	ret = stm32_cryp_dma_check_sg(cryp->in_sg, align_size, AES_BLOCK_SIZE);
	ret2 = stm32_cryp_dma_check_sg(cryp->out_sg, align_size, AES_BLOCK_SIZE);
	if (ret == NO_DMA || ret2 == NO_DMA) {
		kfree(cryp->in_sg);
		cryp->in_sg = NULL;

		kfree(cryp->out_sg);
		cryp->out_sg = NULL;

		cryp->flags &= ~FLG_IN_OUT_DMA;
	} else {
		cryp->flags |= FLG_IN_OUT_DMA;
	}

	return 0;
}

static int stm32_cryp_prepare_req(struct skcipher_request *req,
				  struct aead_request *areq)
{
	struct stm32_cryp_ctx *ctx;
	struct stm32_cryp *cryp;
	struct stm32_cryp_reqctx *rctx;
	struct scatterlist *in_sg, *out_sg;
	int ret;

	if (!req && !areq)
		return -EINVAL;

	ctx = req ? crypto_skcipher_ctx(crypto_skcipher_reqtfm(req)) :
		    crypto_aead_ctx(crypto_aead_reqtfm(areq));

	cryp = ctx->cryp;

	rctx = req ? skcipher_request_ctx(req) : aead_request_ctx(areq);
	rctx->mode &= FLG_MODE_MASK;

	cryp->flags = (cryp->flags & ~FLG_MODE_MASK) | rctx->mode;
	cryp->hw_blocksize = is_aes(cryp) ? AES_BLOCK_SIZE : DES_BLOCK_SIZE;
	cryp->ctx = ctx;

	if (req) {
		cryp->req = req;
		cryp->areq = NULL;
		cryp->header_in = 0;
		cryp->payload_in = req->cryptlen;
		cryp->payload_out = req->cryptlen;
		cryp->authsize = 0;

		in_sg = req->src;
		out_sg = req->dst;

		ret = stm32_cryp_cipher_prepare(cryp, in_sg, out_sg);
		if (ret)
			return ret;

		ret = stm32_cryp_hw_init(cryp);
	} else {
		/*
		 * Length of input and output data:
		 * Encryption case:
		 *  INPUT  = AssocData   ||     PlainText
		 *          <- assoclen ->  <- cryptlen ->
		 *
		 *  OUTPUT = AssocData    ||   CipherText   ||      AuthTag
		 *          <- assoclen ->  <-- cryptlen -->  <- authsize ->
		 *
		 * Decryption case:
		 *  INPUT  =  AssocData     ||    CipherTex   ||       AuthTag
		 *          <- assoclen --->  <---------- cryptlen ---------->
		 *
		 *  OUTPUT = AssocData    ||               PlainText
		 *          <- assoclen ->  <- cryptlen - authsize ->
		 */
		cryp->areq = areq;
		cryp->req = NULL;
		cryp->authsize = crypto_aead_authsize(crypto_aead_reqtfm(areq));
		if (is_encrypt(cryp)) {
			cryp->payload_in = areq->cryptlen;
			cryp->header_in = areq->assoclen;
			cryp->payload_out = areq->cryptlen;
		} else {
			cryp->payload_in = areq->cryptlen - cryp->authsize;
			cryp->header_in = areq->assoclen;
			cryp->payload_out = cryp->payload_in;
		}

		in_sg = areq->src;
		out_sg = areq->dst;

		scatterwalk_start(&cryp->in_walk, in_sg);
		scatterwalk_start(&cryp->out_walk, out_sg);
		/* In output, jump after assoc data */
		scatterwalk_copychunks(NULL, &cryp->out_walk, cryp->areq->assoclen, 2);

		ret = stm32_cryp_hw_init(cryp);
		if (ret)
			return ret;

		ret = stm32_cryp_aead_prepare(cryp, in_sg, out_sg);
	}

	return ret;
}

static int stm32_cryp_cipher_one_req(struct crypto_engine *engine, void *areq)
{
	struct skcipher_request *req = container_of(areq,
						      struct skcipher_request,
						      base);
	struct stm32_cryp_ctx *ctx = crypto_skcipher_ctx(
			crypto_skcipher_reqtfm(req));
	struct stm32_cryp *cryp = ctx->cryp;
	int ret;

	if (!cryp)
		return -ENODEV;

	ret = stm32_cryp_prepare_req(req, NULL);
	if (ret)
		return ret;

	if (cryp->flags & FLG_IN_OUT_DMA)
		ret = stm32_cryp_dma_start(cryp);
	else
		ret = stm32_cryp_it_start(cryp);

	if (ret == -ETIMEDOUT)
		stm32_cryp_finish_req(cryp, ret);

	return ret;
}

static int stm32_cryp_aead_one_req(struct crypto_engine *engine, void *areq)
{
	struct aead_request *req = container_of(areq, struct aead_request,
						base);
	struct stm32_cryp_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
	struct stm32_cryp *cryp = ctx->cryp;
	int err;

	if (!cryp)
		return -ENODEV;

	err = stm32_cryp_prepare_req(NULL, req);
	if (err)
		return err;

	if (!stm32_cryp_get_input_text_len(cryp) && !cryp->header_in &&
	    !(cryp->flags & FLG_HEADER_DMA)) {
		/* No input data to process: get tag and finish */
		stm32_cryp_finish_req(cryp, 0);
		return 0;
	}

	if (cryp->flags & FLG_HEADER_DMA)
		return stm32_cryp_header_dma_start(cryp);

	if (!cryp->header_in && cryp->flags & FLG_IN_OUT_DMA)
		return stm32_cryp_dma_start(cryp);

	return stm32_cryp_it_start(cryp);
}

static int stm32_cryp_read_auth_tag(struct stm32_cryp *cryp)
{
	u32 cfg, size_bit;
	unsigned int i;
	int ret = 0;

	/* Update Config */
	cfg = stm32_cryp_read(cryp, cryp->caps->cr);

	cfg &= ~CR_PH_MASK;
	cfg |= CR_PH_FINAL;
	cfg &= ~CR_DEC_NOT_ENC;
	cfg |= CR_CRYPEN;

	stm32_cryp_write(cryp, cryp->caps->cr, cfg);

	if (is_gcm(cryp)) {
		/* GCM: write aad and payload size (in bits) */
		size_bit = cryp->areq->assoclen * 8;
		if (cryp->caps->swap_final)
			size_bit = (__force u32)cpu_to_be32(size_bit);

		stm32_cryp_write(cryp, cryp->caps->din, 0);
		stm32_cryp_write(cryp, cryp->caps->din, size_bit);

		size_bit = is_encrypt(cryp) ? cryp->areq->cryptlen :
				cryp->areq->cryptlen - cryp->authsize;
		size_bit *= 8;
		if (cryp->caps->swap_final)
			size_bit = (__force u32)cpu_to_be32(size_bit);

		stm32_cryp_write(cryp, cryp->caps->din, 0);
		stm32_cryp_write(cryp, cryp->caps->din, size_bit);
	} else {
		/* CCM: write CTR0 */
		u32 iv32[AES_BLOCK_32];
		u8 *iv = (u8 *)iv32;
		__be32 *biv = (__be32 *)iv32;

		memcpy(iv, cryp->areq->iv, AES_BLOCK_SIZE);
		memset(iv + AES_BLOCK_SIZE - 1 - iv[0], 0, iv[0] + 1);

		for (i = 0; i < AES_BLOCK_32; i++) {
			u32 xiv = iv32[i];

			if (!cryp->caps->padding_wa)
				xiv = be32_to_cpu(biv[i]);
			stm32_cryp_write(cryp, cryp->caps->din, xiv);
		}
	}

	/* Wait for output data */
	ret = stm32_cryp_wait_output(cryp);
	if (ret) {
		dev_err(cryp->dev, "Timeout (read tag)\n");
		return ret;
	}

	if (is_encrypt(cryp)) {
		u32 out_tag[AES_BLOCK_32];

		/* Get and write tag */
		readsl(cryp->regs + cryp->caps->dout, out_tag, AES_BLOCK_32);
		scatterwalk_copychunks(out_tag, &cryp->out_walk, cryp->authsize, 1);
	} else {
		/* Get and check tag */
		u32 in_tag[AES_BLOCK_32], out_tag[AES_BLOCK_32];

		scatterwalk_copychunks(in_tag, &cryp->in_walk, cryp->authsize, 0);
		readsl(cryp->regs + cryp->caps->dout, out_tag, AES_BLOCK_32);

		if (crypto_memneq(in_tag, out_tag, cryp->authsize))
			ret = -EBADMSG;
	}

	/* Disable cryp */
	cfg &= ~CR_CRYPEN;
	stm32_cryp_write(cryp, cryp->caps->cr, cfg);

	return ret;
}

static void stm32_cryp_check_ctr_counter(struct stm32_cryp *cryp)
{
	u32 cr;

	if (unlikely(cryp->last_ctr[3] == cpu_to_be32(0xFFFFFFFF))) {
		/*
		 * In this case, we need to increment manually the ctr counter,
		 * as HW doesn't handle the U32 carry.
		 */
		crypto_inc((u8 *)cryp->last_ctr, sizeof(cryp->last_ctr));

		cr = stm32_cryp_read(cryp, cryp->caps->cr);
		stm32_cryp_write(cryp, cryp->caps->cr, cr & ~CR_CRYPEN);

		stm32_cryp_hw_write_iv(cryp, cryp->last_ctr);

		stm32_cryp_write(cryp, cryp->caps->cr, cr);
	}

	/* The IV registers are BE  */
	cryp->last_ctr[0] = cpu_to_be32(stm32_cryp_read(cryp, cryp->caps->iv0l));
	cryp->last_ctr[1] = cpu_to_be32(stm32_cryp_read(cryp, cryp->caps->iv0r));
	cryp->last_ctr[2] = cpu_to_be32(stm32_cryp_read(cryp, cryp->caps->iv1l));
	cryp->last_ctr[3] = cpu_to_be32(stm32_cryp_read(cryp, cryp->caps->iv1r));
}

static void stm32_cryp_irq_read_data(struct stm32_cryp *cryp)
{
	u32 block[AES_BLOCK_32];

	readsl(cryp->regs + cryp->caps->dout, block, cryp->hw_blocksize / sizeof(u32));
	scatterwalk_copychunks(block, &cryp->out_walk, min_t(size_t, cryp->hw_blocksize,
							     cryp->payload_out), 1);
	cryp->payload_out -= min_t(size_t, cryp->hw_blocksize,
				   cryp->payload_out);
}

static void stm32_cryp_irq_write_block(struct stm32_cryp *cryp)
{
	u32 block[AES_BLOCK_32] = {0};

	scatterwalk_copychunks(block, &cryp->in_walk, min_t(size_t, cryp->hw_blocksize,
							    cryp->payload_in), 0);
	writesl(cryp->regs + cryp->caps->din, block, cryp->hw_blocksize / sizeof(u32));
	cryp->payload_in -= min_t(size_t, cryp->hw_blocksize, cryp->payload_in);
}

static void stm32_cryp_irq_write_gcm_padded_data(struct stm32_cryp *cryp)
{
	int err;
	u32 cfg, block[AES_BLOCK_32] = {0};
	unsigned int i;

	/* 'Special workaround' procedure described in the datasheet */

	/* a) disable ip */
	stm32_cryp_write(cryp, cryp->caps->imsc, 0);
	cfg = stm32_cryp_read(cryp, cryp->caps->cr);
	cfg &= ~CR_CRYPEN;
	stm32_cryp_write(cryp, cryp->caps->cr, cfg);

	/* b) Update IV1R */
	stm32_cryp_write(cryp, cryp->caps->iv1r, cryp->gcm_ctr - 2);

	/* c) change mode to CTR */
	cfg &= ~CR_ALGO_MASK;
	cfg |= CR_AES_CTR;
	stm32_cryp_write(cryp, cryp->caps->cr, cfg);

	/* a) enable IP */
	cfg |= CR_CRYPEN;
	stm32_cryp_write(cryp, cryp->caps->cr, cfg);

	/* b) pad and write the last block */
	stm32_cryp_irq_write_block(cryp);
	/* wait end of process */
	err = stm32_cryp_wait_output(cryp);
	if (err) {
		dev_err(cryp->dev, "Timeout (write gcm last data)\n");
		return stm32_cryp_finish_req(cryp, err);
	}

	/* c) get and store encrypted data */
	/*
	 * Same code as stm32_cryp_irq_read_data(), but we want to store
	 * block value
	 */
	readsl(cryp->regs + cryp->caps->dout, block, cryp->hw_blocksize / sizeof(u32));

	scatterwalk_copychunks(block, &cryp->out_walk, min_t(size_t, cryp->hw_blocksize,
							     cryp->payload_out), 1);
	cryp->payload_out -= min_t(size_t, cryp->hw_blocksize,
				   cryp->payload_out);

	/* d) change mode back to AES GCM */
	cfg &= ~CR_ALGO_MASK;
	cfg |= CR_AES_GCM;
	stm32_cryp_write(cryp, cryp->caps->cr, cfg);

	/* e) change phase to Final */
	cfg &= ~CR_PH_MASK;
	cfg |= CR_PH_FINAL;
	stm32_cryp_write(cryp, cryp->caps->cr, cfg);

	/* f) write padded data */
	writesl(cryp->regs + cryp->caps->din, block, AES_BLOCK_32);

	/* g) Empty fifo out */
	err = stm32_cryp_wait_output(cryp);
	if (err) {
		dev_err(cryp->dev, "Timeout (write gcm padded data)\n");
		return stm32_cryp_finish_req(cryp, err);
	}

	for (i = 0; i < AES_BLOCK_32; i++)
		stm32_cryp_read(cryp, cryp->caps->dout);

	/* h) run the he normal Final phase */
	stm32_cryp_finish_req(cryp, 0);
}

static void stm32_cryp_irq_set_npblb(struct stm32_cryp *cryp)
{
	u32 cfg;

	/* disable ip, set NPBLB and reneable ip */
	cfg = stm32_cryp_read(cryp, cryp->caps->cr);
	cfg &= ~CR_CRYPEN;
	stm32_cryp_write(cryp, cryp->caps->cr, cfg);

	cfg |= (cryp->hw_blocksize - cryp->payload_in) << CR_NBPBL_SHIFT;
	cfg |= CR_CRYPEN;
	stm32_cryp_write(cryp, cryp->caps->cr, cfg);
}

static void stm32_cryp_irq_write_ccm_padded_data(struct stm32_cryp *cryp)
{
	int err = 0;
	u32 cfg, iv1tmp;
	u32 cstmp1[AES_BLOCK_32], cstmp2[AES_BLOCK_32];
	u32 block[AES_BLOCK_32] = {0};
	unsigned int i;

	/* 'Special workaround' procedure described in the datasheet */

	/* a) disable ip */
	stm32_cryp_write(cryp, cryp->caps->imsc, 0);

	cfg = stm32_cryp_read(cryp, cryp->caps->cr);
	cfg &= ~CR_CRYPEN;
	stm32_cryp_write(cryp, cryp->caps->cr, cfg);

	/* b) get IV1 from CRYP_CSGCMCCM7 */
	iv1tmp = stm32_cryp_read(cryp, CRYP_CSGCMCCM0R + 7 * 4);

	/* c) Load CRYP_CSGCMCCMxR */
	for (i = 0; i < ARRAY_SIZE(cstmp1); i++)
		cstmp1[i] = stm32_cryp_read(cryp, CRYP_CSGCMCCM0R + i * 4);

	/* d) Write IV1R */
	stm32_cryp_write(cryp, cryp->caps->iv1r, iv1tmp);

	/* e) change mode to CTR */
	cfg &= ~CR_ALGO_MASK;
	cfg |= CR_AES_CTR;
	stm32_cryp_write(cryp, cryp->caps->cr, cfg);

	/* a) enable IP */
	cfg |= CR_CRYPEN;
	stm32_cryp_write(cryp, cryp->caps->cr, cfg);

	/* b) pad and write the last block */
	stm32_cryp_irq_write_block(cryp);
	/* wait end of process */
	err = stm32_cryp_wait_output(cryp);
	if (err) {
		dev_err(cryp->dev, "Timeout (write ccm padded data)\n");
		return stm32_cryp_finish_req(cryp, err);
	}

	/* c) get and store decrypted data */
	/*
	 * Same code as stm32_cryp_irq_read_data(), but we want to store
	 * block value
	 */
	readsl(cryp->regs + cryp->caps->dout, block, cryp->hw_blocksize / sizeof(u32));

	scatterwalk_copychunks(block, &cryp->out_walk, min_t(size_t, cryp->hw_blocksize,
							     cryp->payload_out), 1);
	cryp->payload_out -= min_t(size_t, cryp->hw_blocksize, cryp->payload_out);

	/* d) Load again CRYP_CSGCMCCMxR */
	for (i = 0; i < ARRAY_SIZE(cstmp2); i++)
		cstmp2[i] = stm32_cryp_read(cryp, CRYP_CSGCMCCM0R + i * 4);

	/* e) change mode back to AES CCM */
	cfg &= ~CR_ALGO_MASK;
	cfg |= CR_AES_CCM;
	stm32_cryp_write(cryp, cryp->caps->cr, cfg);

	/* f) change phase to header */
	cfg &= ~CR_PH_MASK;
	cfg |= CR_PH_HEADER;
	stm32_cryp_write(cryp, cryp->caps->cr, cfg);

	/* g) XOR and write padded data */
	for (i = 0; i < ARRAY_SIZE(block); i++) {
		block[i] ^= cstmp1[i];
		block[i] ^= cstmp2[i];
		stm32_cryp_write(cryp, cryp->caps->din, block[i]);
	}

	/* h) wait for completion */
	err = stm32_cryp_wait_busy(cryp);
	if (err)
		dev_err(cryp->dev, "Timeout (write ccm padded data)\n");

	/* i) run the he normal Final phase */
	stm32_cryp_finish_req(cryp, err);
}

static void stm32_cryp_irq_write_data(struct stm32_cryp *cryp)
{
	if (unlikely(!cryp->payload_in)) {
		dev_warn(cryp->dev, "No more data to process\n");
		return;
	}

	if (unlikely(cryp->payload_in < AES_BLOCK_SIZE &&
		     (stm32_cryp_get_hw_mode(cryp) == CR_AES_GCM) &&
		     is_encrypt(cryp))) {
		/* Padding for AES GCM encryption */
		if (cryp->caps->padding_wa) {
			/* Special case 1 */
			stm32_cryp_irq_write_gcm_padded_data(cryp);
			return;
		}

		/* Setting padding bytes (NBBLB) */
		stm32_cryp_irq_set_npblb(cryp);
	}

	if (unlikely((cryp->payload_in < AES_BLOCK_SIZE) &&
		     (stm32_cryp_get_hw_mode(cryp) == CR_AES_CCM) &&
		     is_decrypt(cryp))) {
		/* Padding for AES CCM decryption */
		if (cryp->caps->padding_wa) {
			/* Special case 2 */
			stm32_cryp_irq_write_ccm_padded_data(cryp);
			return;
		}

		/* Setting padding bytes (NBBLB) */
		stm32_cryp_irq_set_npblb(cryp);
	}

	if (is_aes(cryp) && is_ctr(cryp))
		stm32_cryp_check_ctr_counter(cryp);

	stm32_cryp_irq_write_block(cryp);
}

static void stm32_cryp_irq_write_gcmccm_header(struct stm32_cryp *cryp)
{
	u32 block[AES_BLOCK_32] = {0};
	size_t written;

	written = min_t(size_t, AES_BLOCK_SIZE, cryp->header_in);

	scatterwalk_copychunks(block, &cryp->in_walk, written, 0);

	writesl(cryp->regs + cryp->caps->din, block, AES_BLOCK_32);

	cryp->header_in -= written;

	stm32_crypt_gcmccm_end_header(cryp);
}

static irqreturn_t stm32_cryp_irq_thread(int irq, void *arg)
{
	struct stm32_cryp *cryp = arg;
	u32 ph;
	u32 it_mask = stm32_cryp_read(cryp, cryp->caps->imsc);

	if (cryp->irq_status & MISR_OUT)
		/* Output FIFO IRQ: read data */
		stm32_cryp_irq_read_data(cryp);

	if (cryp->irq_status & MISR_IN) {
		if (is_gcm(cryp) || is_ccm(cryp)) {
			ph = stm32_cryp_read(cryp, cryp->caps->cr) & CR_PH_MASK;
			if (unlikely(ph == CR_PH_HEADER))
				/* Write Header */
				stm32_cryp_irq_write_gcmccm_header(cryp);
			else
				/* Input FIFO IRQ: write data */
				stm32_cryp_irq_write_data(cryp);
			if (is_gcm(cryp))
				cryp->gcm_ctr++;
		} else {
			/* Input FIFO IRQ: write data */
			stm32_cryp_irq_write_data(cryp);
		}
	}

	/* Mask useless interrupts */
	if (!cryp->payload_in && !cryp->header_in)
		it_mask &= ~IMSCR_IN;
	if (!cryp->payload_out)
		it_mask &= ~IMSCR_OUT;
	stm32_cryp_write(cryp, cryp->caps->imsc, it_mask);

	if (!cryp->payload_in && !cryp->header_in && !cryp->payload_out) {
		local_bh_disable();
		stm32_cryp_finish_req(cryp, 0);
		local_bh_enable();
	}

	return IRQ_HANDLED;
}

static irqreturn_t stm32_cryp_irq(int irq, void *arg)
{
	struct stm32_cryp *cryp = arg;

	cryp->irq_status = stm32_cryp_read(cryp, cryp->caps->mis);

	return IRQ_WAKE_THREAD;
}

static int stm32_cryp_dma_init(struct stm32_cryp *cryp)
{
	struct dma_slave_config dma_conf;
	struct dma_chan *chan;
	int ret;

	memset(&dma_conf, 0, sizeof(dma_conf));

	dma_conf.direction = DMA_MEM_TO_DEV;
	dma_conf.dst_addr = cryp->phys_base + cryp->caps->din;
	dma_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
	dma_conf.dst_maxburst = CRYP_DMA_BURST_REG;
	dma_conf.device_fc = false;

	chan = dma_request_chan(cryp->dev, "in");
	if (IS_ERR(chan))
		return PTR_ERR(chan);

	cryp->dma_lch_in = chan;
	ret = dmaengine_slave_config(cryp->dma_lch_in, &dma_conf);
	if (ret) {
		dma_release_channel(cryp->dma_lch_in);
		cryp->dma_lch_in = NULL;
		dev_err(cryp->dev, "Couldn't configure DMA in slave.\n");
		return ret;
	}

	memset(&dma_conf, 0, sizeof(dma_conf));

	dma_conf.direction = DMA_DEV_TO_MEM;
	dma_conf.src_addr = cryp->phys_base + cryp->caps->dout;
	dma_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
	dma_conf.src_maxburst = CRYP_DMA_BURST_REG;
	dma_conf.device_fc = false;

	chan = dma_request_chan(cryp->dev, "out");
	if (IS_ERR(chan)) {
		dma_release_channel(cryp->dma_lch_in);
		cryp->dma_lch_in = NULL;
		return PTR_ERR(chan);
	}

	cryp->dma_lch_out = chan;

	ret = dmaengine_slave_config(cryp->dma_lch_out, &dma_conf);
	if (ret) {
		dma_release_channel(cryp->dma_lch_out);
		cryp->dma_lch_out = NULL;
		dev_err(cryp->dev, "Couldn't configure DMA out slave.\n");
		dma_release_channel(cryp->dma_lch_in);
		cryp->dma_lch_in = NULL;
		return ret;
	}

	init_completion(&cryp->dma_completion);

	return 0;
}

static struct skcipher_engine_alg crypto_algs[] = {
{
	.base = {
		.base.cra_name		= "ecb(aes)",
		.base.cra_driver_name	= "stm32-ecb-aes",
		.base.cra_priority	= 300,
		.base.cra_flags		= CRYPTO_ALG_ASYNC | CRYPTO_ALG_KERN_DRIVER_ONLY,
		.base.cra_blocksize	= AES_BLOCK_SIZE,
		.base.cra_ctxsize	= sizeof(struct stm32_cryp_ctx),
		.base.cra_alignmask	= 0,
		.base.cra_module	= THIS_MODULE,

		.init			= stm32_cryp_init_tfm,
		.min_keysize		= AES_MIN_KEY_SIZE,
		.max_keysize		= AES_MAX_KEY_SIZE,
		.setkey			= stm32_cryp_aes_setkey,
		.encrypt		= stm32_cryp_aes_ecb_encrypt,
		.decrypt		= stm32_cryp_aes_ecb_decrypt,
	},
	.op = {
		.do_one_request = stm32_cryp_cipher_one_req,
	},
},
{
	.base = {
		.base.cra_name		= "cbc(aes)",
		.base.cra_driver_name	= "stm32-cbc-aes",
		.base.cra_priority	= 300,
		.base.cra_flags		= CRYPTO_ALG_ASYNC | CRYPTO_ALG_KERN_DRIVER_ONLY,
		.base.cra_blocksize	= AES_BLOCK_SIZE,
		.base.cra_ctxsize	= sizeof(struct stm32_cryp_ctx),
		.base.cra_alignmask	= 0,
		.base.cra_module	= THIS_MODULE,

		.init			= stm32_cryp_init_tfm,
		.min_keysize		= AES_MIN_KEY_SIZE,
		.max_keysize		= AES_MAX_KEY_SIZE,
		.ivsize			= AES_BLOCK_SIZE,
		.setkey			= stm32_cryp_aes_setkey,
		.encrypt		= stm32_cryp_aes_cbc_encrypt,
		.decrypt		= stm32_cryp_aes_cbc_decrypt,
	},
	.op = {
		.do_one_request = stm32_cryp_cipher_one_req,
	},
},
{
	.base = {
		.base.cra_name		= "ctr(aes)",
		.base.cra_driver_name	= "stm32-ctr-aes",
		.base.cra_priority	= 300,
		.base.cra_flags		= CRYPTO_ALG_ASYNC | CRYPTO_ALG_KERN_DRIVER_ONLY,
		.base.cra_blocksize	= 1,
		.base.cra_ctxsize	= sizeof(struct stm32_cryp_ctx),
		.base.cra_alignmask	= 0,
		.base.cra_module	= THIS_MODULE,

		.init			= stm32_cryp_init_tfm,
		.min_keysize		= AES_MIN_KEY_SIZE,
		.max_keysize		= AES_MAX_KEY_SIZE,
		.ivsize			= AES_BLOCK_SIZE,
		.setkey			= stm32_cryp_aes_setkey,
		.encrypt		= stm32_cryp_aes_ctr_encrypt,
		.decrypt		= stm32_cryp_aes_ctr_decrypt,
	},
	.op = {
		.do_one_request = stm32_cryp_cipher_one_req,
	},
},
{
	.base = {
		.base.cra_name		= "ecb(des)",
		.base.cra_driver_name	= "stm32-ecb-des",
		.base.cra_priority	= 300,
		.base.cra_flags		= CRYPTO_ALG_ASYNC | CRYPTO_ALG_KERN_DRIVER_ONLY,
		.base.cra_blocksize	= DES_BLOCK_SIZE,
		.base.cra_ctxsize	= sizeof(struct stm32_cryp_ctx),
		.base.cra_alignmask	= 0,
		.base.cra_module	= THIS_MODULE,

		.init			= stm32_cryp_init_tfm,
		.min_keysize		= DES_BLOCK_SIZE,
		.max_keysize		= DES_BLOCK_SIZE,
		.setkey			= stm32_cryp_des_setkey,
		.encrypt		= stm32_cryp_des_ecb_encrypt,
		.decrypt		= stm32_cryp_des_ecb_decrypt,
	},
	.op = {
		.do_one_request = stm32_cryp_cipher_one_req,
	},
},
{
	.base = {
		.base.cra_name		= "cbc(des)",
		.base.cra_driver_name	= "stm32-cbc-des",
		.base.cra_priority	= 300,
		.base.cra_flags		= CRYPTO_ALG_ASYNC | CRYPTO_ALG_KERN_DRIVER_ONLY,
		.base.cra_blocksize	= DES_BLOCK_SIZE,
		.base.cra_ctxsize	= sizeof(struct stm32_cryp_ctx),
		.base.cra_alignmask	= 0,
		.base.cra_module	= THIS_MODULE,

		.init			= stm32_cryp_init_tfm,
		.min_keysize		= DES_BLOCK_SIZE,
		.max_keysize		= DES_BLOCK_SIZE,
		.ivsize			= DES_BLOCK_SIZE,
		.setkey			= stm32_cryp_des_setkey,
		.encrypt		= stm32_cryp_des_cbc_encrypt,
		.decrypt		= stm32_cryp_des_cbc_decrypt,
	},
	.op = {
		.do_one_request = stm32_cryp_cipher_one_req,
	},
},
{
	.base = {
		.base.cra_name		= "ecb(des3_ede)",
		.base.cra_driver_name	= "stm32-ecb-des3",
		.base.cra_priority	= 300,
		.base.cra_flags		= CRYPTO_ALG_ASYNC | CRYPTO_ALG_KERN_DRIVER_ONLY,
		.base.cra_blocksize	= DES_BLOCK_SIZE,
		.base.cra_ctxsize	= sizeof(struct stm32_cryp_ctx),
		.base.cra_alignmask	= 0,
		.base.cra_module	= THIS_MODULE,

		.init			= stm32_cryp_init_tfm,
		.min_keysize		= 3 * DES_BLOCK_SIZE,
		.max_keysize		= 3 * DES_BLOCK_SIZE,
		.setkey			= stm32_cryp_tdes_setkey,
		.encrypt		= stm32_cryp_tdes_ecb_encrypt,
		.decrypt		= stm32_cryp_tdes_ecb_decrypt,
	},
	.op = {
		.do_one_request = stm32_cryp_cipher_one_req,
	},
},
{
	.base = {
		.base.cra_name		= "cbc(des3_ede)",
		.base.cra_driver_name	= "stm32-cbc-des3",
		.base.cra_priority	= 300,
		.base.cra_flags		= CRYPTO_ALG_ASYNC | CRYPTO_ALG_KERN_DRIVER_ONLY,
		.base.cra_blocksize	= DES_BLOCK_SIZE,
		.base.cra_ctxsize	= sizeof(struct stm32_cryp_ctx),
		.base.cra_alignmask	= 0,
		.base.cra_module	= THIS_MODULE,

		.init			= stm32_cryp_init_tfm,
		.min_keysize		= 3 * DES_BLOCK_SIZE,
		.max_keysize		= 3 * DES_BLOCK_SIZE,
		.ivsize			= DES_BLOCK_SIZE,
		.setkey			= stm32_cryp_tdes_setkey,
		.encrypt		= stm32_cryp_tdes_cbc_encrypt,
		.decrypt		= stm32_cryp_tdes_cbc_decrypt,
	},
	.op = {
		.do_one_request = stm32_cryp_cipher_one_req,
	},
},
};

static struct aead_engine_alg aead_algs[] = {
{
	.base.setkey		= stm32_cryp_aes_aead_setkey,
	.base.setauthsize	= stm32_cryp_aes_gcm_setauthsize,
	.base.encrypt		= stm32_cryp_aes_gcm_encrypt,
	.base.decrypt		= stm32_cryp_aes_gcm_decrypt,
	.base.init		= stm32_cryp_aes_aead_init,
	.base.ivsize		= 12,
	.base.maxauthsize	= AES_BLOCK_SIZE,

	.base.base = {
		.cra_name		= "gcm(aes)",
		.cra_driver_name	= "stm32-gcm-aes",
		.cra_priority		= 300,
		.cra_flags		= CRYPTO_ALG_ASYNC | CRYPTO_ALG_KERN_DRIVER_ONLY,
		.cra_blocksize		= 1,
		.cra_ctxsize		= sizeof(struct stm32_cryp_ctx),
		.cra_alignmask		= 0,
		.cra_module		= THIS_MODULE,
	},
	.op = {
		.do_one_request = stm32_cryp_aead_one_req,
	},
},
{
	.base.setkey		= stm32_cryp_aes_aead_setkey,
	.base.setauthsize	= stm32_cryp_aes_ccm_setauthsize,
	.base.encrypt		= stm32_cryp_aes_ccm_encrypt,
	.base.decrypt		= stm32_cryp_aes_ccm_decrypt,
	.base.init		= stm32_cryp_aes_aead_init,
	.base.ivsize		= AES_BLOCK_SIZE,
	.base.maxauthsize	= AES_BLOCK_SIZE,

	.base.base = {
		.cra_name		= "ccm(aes)",
		.cra_driver_name	= "stm32-ccm-aes",
		.cra_priority		= 300,
		.cra_flags		= CRYPTO_ALG_ASYNC | CRYPTO_ALG_KERN_DRIVER_ONLY,
		.cra_blocksize		= 1,
		.cra_ctxsize		= sizeof(struct stm32_cryp_ctx),
		.cra_alignmask		= 0,
		.cra_module		= THIS_MODULE,
	},
	.op = {
		.do_one_request = stm32_cryp_aead_one_req,
	},
},
};

static const struct stm32_cryp_caps ux500_data = {
	.aeads_support = false,
	.linear_aes_key = true,
	.kp_mode = false,
	.iv_protection = true,
	.swap_final = true,
	.padding_wa = true,
	.cr = UX500_CRYP_CR,
	.sr = UX500_CRYP_SR,
	.din = UX500_CRYP_DIN,
	.dout = UX500_CRYP_DOUT,
	.dmacr = UX500_CRYP_DMACR,
	.imsc = UX500_CRYP_IMSC,
	.mis = UX500_CRYP_MIS,
	.k1l = UX500_CRYP_K1L,
	.k1r = UX500_CRYP_K1R,
	.k3r = UX500_CRYP_K3R,
	.iv0l = UX500_CRYP_IV0L,
	.iv0r = UX500_CRYP_IV0R,
	.iv1l = UX500_CRYP_IV1L,
	.iv1r = UX500_CRYP_IV1R,
};

static const struct stm32_cryp_caps f7_data = {
	.aeads_support = true,
	.linear_aes_key = false,
	.kp_mode = true,
	.iv_protection = false,
	.swap_final = true,
	.padding_wa = true,
	.cr = CRYP_CR,
	.sr = CRYP_SR,
	.din = CRYP_DIN,
	.dout = CRYP_DOUT,
	.dmacr = CRYP_DMACR,
	.imsc = CRYP_IMSCR,
	.mis = CRYP_MISR,
	.k1l = CRYP_K1LR,
	.k1r = CRYP_K1RR,
	.k3r = CRYP_K3RR,
	.iv0l = CRYP_IV0LR,
	.iv0r = CRYP_IV0RR,
	.iv1l = CRYP_IV1LR,
	.iv1r = CRYP_IV1RR,
};

static const struct stm32_cryp_caps mp1_data = {
	.aeads_support = true,
	.linear_aes_key = false,
	.kp_mode = true,
	.iv_protection = false,
	.swap_final = false,
	.padding_wa = false,
	.cr = CRYP_CR,
	.sr = CRYP_SR,
	.din = CRYP_DIN,
	.dout = CRYP_DOUT,
	.dmacr = CRYP_DMACR,
	.imsc = CRYP_IMSCR,
	.mis = CRYP_MISR,
	.k1l = CRYP_K1LR,
	.k1r = CRYP_K1RR,
	.k3r = CRYP_K3RR,
	.iv0l = CRYP_IV0LR,
	.iv0r = CRYP_IV0RR,
	.iv1l = CRYP_IV1LR,
	.iv1r = CRYP_IV1RR,
};

static const struct of_device_id stm32_dt_ids[] = {
	{ .compatible = "stericsson,ux500-cryp", .data = &ux500_data},
	{ .compatible = "st,stm32f756-cryp", .data = &f7_data},
	{ .compatible = "st,stm32mp1-cryp", .data = &mp1_data},
	{},
};
MODULE_DEVICE_TABLE(of, stm32_dt_ids);

static int stm32_cryp_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct stm32_cryp *cryp;
	struct reset_control *rst;
	int irq, ret;

	cryp = devm_kzalloc(dev, sizeof(*cryp), GFP_KERNEL);
	if (!cryp)
		return -ENOMEM;

	cryp->caps = of_device_get_match_data(dev);
	if (!cryp->caps)
		return -ENODEV;

	cryp->dev = dev;

	cryp->regs = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(cryp->regs))
		return PTR_ERR(cryp->regs);

	cryp->phys_base = platform_get_resource(pdev, IORESOURCE_MEM, 0)->start;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return irq;

	ret = devm_request_threaded_irq(dev, irq, stm32_cryp_irq,
					stm32_cryp_irq_thread, IRQF_ONESHOT,
					dev_name(dev), cryp);
	if (ret) {
		dev_err(dev, "Cannot grab IRQ\n");
		return ret;
	}

	cryp->clk = devm_clk_get(dev, NULL);
	if (IS_ERR(cryp->clk)) {
		dev_err_probe(dev, PTR_ERR(cryp->clk), "Could not get clock\n");

		return PTR_ERR(cryp->clk);
	}

	ret = clk_prepare_enable(cryp->clk);
	if (ret) {
		dev_err(cryp->dev, "Failed to enable clock\n");
		return ret;
	}

	pm_runtime_set_autosuspend_delay(dev, CRYP_AUTOSUSPEND_DELAY);
	pm_runtime_use_autosuspend(dev);

	pm_runtime_get_noresume(dev);
	pm_runtime_set_active(dev);
	pm_runtime_enable(dev);

	rst = devm_reset_control_get(dev, NULL);
	if (IS_ERR(rst)) {
		ret = PTR_ERR(rst);
		if (ret == -EPROBE_DEFER)
			goto err_rst;
	} else {
		reset_control_assert(rst);
		udelay(2);
		reset_control_deassert(rst);
	}

	platform_set_drvdata(pdev, cryp);

	ret = stm32_cryp_dma_init(cryp);
	switch (ret) {
	case 0:
		break;
	case -ENODEV:
		dev_dbg(dev, "DMA mode not available\n");
		break;
	default:
		goto err_dma;
	}

	spin_lock(&cryp_list.lock);
	list_add(&cryp->list, &cryp_list.dev_list);
	spin_unlock(&cryp_list.lock);

	/* Initialize crypto engine */
	cryp->engine = crypto_engine_alloc_init(dev, 1);
	if (!cryp->engine) {
		dev_err(dev, "Could not init crypto engine\n");
		ret = -ENOMEM;
		goto err_engine1;
	}

	ret = crypto_engine_start(cryp->engine);
	if (ret) {
		dev_err(dev, "Could not start crypto engine\n");
		goto err_engine2;
	}

	ret = crypto_engine_register_skciphers(crypto_algs, ARRAY_SIZE(crypto_algs));
	if (ret) {
		dev_err(dev, "Could not register algs\n");
		goto err_algs;
	}

	if (cryp->caps->aeads_support) {
		ret = crypto_engine_register_aeads(aead_algs, ARRAY_SIZE(aead_algs));
		if (ret)
			goto err_aead_algs;
	}

	dev_info(dev, "Initialized\n");

	pm_runtime_put_sync(dev);

	return 0;

err_aead_algs:
	crypto_engine_unregister_skciphers(crypto_algs, ARRAY_SIZE(crypto_algs));
err_algs:
err_engine2:
	crypto_engine_exit(cryp->engine);
err_engine1:
	spin_lock(&cryp_list.lock);
	list_del(&cryp->list);
	spin_unlock(&cryp_list.lock);

	if (cryp->dma_lch_in)
		dma_release_channel(cryp->dma_lch_in);
	if (cryp->dma_lch_out)
		dma_release_channel(cryp->dma_lch_out);
err_dma:
err_rst:
	pm_runtime_disable(dev);
	pm_runtime_put_noidle(dev);

	clk_disable_unprepare(cryp->clk);

	return ret;
}

static void stm32_cryp_remove(struct platform_device *pdev)
{
	struct stm32_cryp *cryp = platform_get_drvdata(pdev);
	int ret;

	ret = pm_runtime_get_sync(cryp->dev);

	if (cryp->caps->aeads_support)
		crypto_engine_unregister_aeads(aead_algs, ARRAY_SIZE(aead_algs));
	crypto_engine_unregister_skciphers(crypto_algs, ARRAY_SIZE(crypto_algs));

	crypto_engine_exit(cryp->engine);

	spin_lock(&cryp_list.lock);
	list_del(&cryp->list);
	spin_unlock(&cryp_list.lock);

	if (cryp->dma_lch_in)
		dma_release_channel(cryp->dma_lch_in);

	if (cryp->dma_lch_out)
		dma_release_channel(cryp->dma_lch_out);

	pm_runtime_disable(cryp->dev);
	pm_runtime_put_noidle(cryp->dev);

	if (ret >= 0)
		clk_disable_unprepare(cryp->clk);
}

#ifdef CONFIG_PM
static int stm32_cryp_runtime_suspend(struct device *dev)
{
	struct stm32_cryp *cryp = dev_get_drvdata(dev);

	clk_disable_unprepare(cryp->clk);

	return 0;
}

static int stm32_cryp_runtime_resume(struct device *dev)
{
	struct stm32_cryp *cryp = dev_get_drvdata(dev);
	int ret;

	ret = clk_prepare_enable(cryp->clk);
	if (ret) {
		dev_err(cryp->dev, "Failed to prepare_enable clock\n");
		return ret;
	}

	return 0;
}
#endif

static const struct dev_pm_ops stm32_cryp_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
				pm_runtime_force_resume)
	SET_RUNTIME_PM_OPS(stm32_cryp_runtime_suspend,
			   stm32_cryp_runtime_resume, NULL)
};

static struct platform_driver stm32_cryp_driver = {
	.probe  = stm32_cryp_probe,
	.remove_new = stm32_cryp_remove,
	.driver = {
		.name           = DRIVER_NAME,
		.pm		= &stm32_cryp_pm_ops,
		.of_match_table = stm32_dt_ids,
	},
};

module_platform_driver(stm32_cryp_driver);

MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
MODULE_DESCRIPTION("STMicrolectronics STM32 CRYP hardware driver");
MODULE_LICENSE("GPL");