crypto: mv_cesa - Add support for Orion5X crypto engine

This adds support for Marvell's Cryptographic Engines and Security
Accelerator (CESA) which can be found on a few SoC.
Tested with dm-crypt.

Acked-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 606 insertions, 0 deletions

diff --git a/drivers/crypto/mv_cesa.c b/drivers/crypto/mv_cesa.c
new file mode 100644
index 000000000000..b21ef635f352
--- /dev/null
+++ b/drivers/crypto/mv_cesa.c
@@ -0,0 +1,606 @@
+/*
+ * Support for Marvell's crypto engine which can be found on some Orion5X
+ * boards.
+ *
+ * Author: Sebastian Andrzej Siewior < sebastian at breakpoint dot cc >
+ * License: GPLv2
+ *
+ */
+#include <crypto/aes.h>
+#include <crypto/algapi.h>
+#include <linux/crypto.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kthread.h>
+#include <linux/platform_device.h>
+#include <linux/scatterlist.h>
+
+#include "mv_cesa.h"
+/*
+ * STM:
+ *   /---------------------------------------\
+ *   |					     | request complete
+ *  \./					     |
+ * IDLE -> new request -> BUSY -> done -> DEQUEUE
+ *                         /°\               |
+ *			    |		     | more scatter entries
+ *			    \________________/
+ */
+enum engine_status {
+	ENGINE_IDLE,
+	ENGINE_BUSY,
+	ENGINE_W_DEQUEUE,
+};
+
+/**
+ * struct req_progress - used for every crypt request
+ * @src_sg_it:		sg iterator for src
+ * @dst_sg_it:		sg iterator for dst
+ * @sg_src_left:	bytes left in src to process (scatter list)
+ * @src_start:		offset to add to src start position (scatter list)
+ * @crypt_len:		length of current crypt process
+ * @sg_dst_left:	bytes left dst to process in this scatter list
+ * @dst_start:		offset to add to dst start position (scatter list)
+ * @total_req_bytes:	total number of bytes processed (request).
+ *
+ * sg helper are used to iterate over the scatterlist. Since the size of the
+ * SRAM may be less than the scatter size, this struct struct is used to keep
+ * track of progress within current scatterlist.
+ */
+struct req_progress {
+	struct sg_mapping_iter src_sg_it;
+	struct sg_mapping_iter dst_sg_it;
+
+	/* src mostly */
+	int sg_src_left;
+	int src_start;
+	int crypt_len;
+	/* dst mostly */
+	int sg_dst_left;
+	int dst_start;
+	int total_req_bytes;
+};
+
+struct crypto_priv {
+	void __iomem *reg;
+	void __iomem *sram;
+	int irq;
+	struct task_struct *queue_th;
+
+	/* the lock protects queue and eng_st */
+	spinlock_t lock;
+	struct crypto_queue queue;
+	enum engine_status eng_st;
+	struct ablkcipher_request *cur_req;
+	struct req_progress p;
+	int max_req_size;
+	int sram_size;
+};
+
+static struct crypto_priv *cpg;
+
+struct mv_ctx {
+	u8 aes_enc_key[AES_KEY_LEN];
+	u32 aes_dec_key[8];
+	int key_len;
+	u32 need_calc_aes_dkey;
+};
+
+enum crypto_op {
+	COP_AES_ECB,
+	COP_AES_CBC,
+};
+
+struct mv_req_ctx {
+	enum crypto_op op;
+	int decrypt;
+};
+
+static void compute_aes_dec_key(struct mv_ctx *ctx)
+{
+	struct crypto_aes_ctx gen_aes_key;
+	int key_pos;
+
+	if (!ctx->need_calc_aes_dkey)
+		return;
+
+	crypto_aes_expand_key(&gen_aes_key, ctx->aes_enc_key, ctx->key_len);
+
+	key_pos = ctx->key_len + 24;
+	memcpy(ctx->aes_dec_key, &gen_aes_key.key_enc[key_pos], 4 * 4);
+	switch (ctx->key_len) {
+	case AES_KEYSIZE_256:
+		key_pos -= 2;
+		/* fall */
+	case AES_KEYSIZE_192:
+		key_pos -= 2;
+		memcpy(&ctx->aes_dec_key[4], &gen_aes_key.key_enc[key_pos],
+				4 * 4);
+		break;
+	}
+	ctx->need_calc_aes_dkey = 0;
+}
+
+static int mv_setkey_aes(struct crypto_ablkcipher *cipher, const u8 *key,
+		unsigned int len)
+{
+	struct crypto_tfm *tfm = crypto_ablkcipher_tfm(cipher);
+	struct mv_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	switch (len) {
+	case AES_KEYSIZE_128:
+	case AES_KEYSIZE_192:
+	case AES_KEYSIZE_256:
+		break;
+	default:
+		crypto_ablkcipher_set_flags(cipher, CRYPTO_TFM_RES_BAD_KEY_LEN);
+		return -EINVAL;
+	}
+	ctx->key_len = len;
+	ctx->need_calc_aes_dkey = 1;
+
+	memcpy(ctx->aes_enc_key, key, AES_KEY_LEN);
+	return 0;
+}
+
+static void setup_data_in(struct ablkcipher_request *req)
+{
+	int ret;
+	void *buf;
+
+	if (!cpg->p.sg_src_left) {
+		ret = sg_miter_next(&cpg->p.src_sg_it);
+		BUG_ON(!ret);
+		cpg->p.sg_src_left = cpg->p.src_sg_it.length;
+		cpg->p.src_start = 0;
+	}
+
+	cpg->p.crypt_len = min(cpg->p.sg_src_left, cpg->max_req_size);
+
+	buf = cpg->p.src_sg_it.addr;
+	buf += cpg->p.src_start;
+
+	memcpy(cpg->sram + SRAM_DATA_IN_START, buf, cpg->p.crypt_len);
+
+	cpg->p.sg_src_left -= cpg->p.crypt_len;
+	cpg->p.src_start += cpg->p.crypt_len;
+}
+
+static void mv_process_current_q(int first_block)
+{
+	struct ablkcipher_request *req = cpg->cur_req;
+	struct mv_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
+	struct mv_req_ctx *req_ctx = ablkcipher_request_ctx(req);
+	struct sec_accel_config op;
+
+	switch (req_ctx->op) {
+	case COP_AES_ECB:
+		op.config = CFG_OP_CRYPT_ONLY | CFG_ENCM_AES | CFG_ENC_MODE_ECB;
+		break;
+	case COP_AES_CBC:
+		op.config = CFG_OP_CRYPT_ONLY | CFG_ENCM_AES | CFG_ENC_MODE_CBC;
+		op.enc_iv = ENC_IV_POINT(SRAM_DATA_IV) |
+			ENC_IV_BUF_POINT(SRAM_DATA_IV_BUF);
+		if (first_block)
+			memcpy(cpg->sram + SRAM_DATA_IV, req->info, 16);
+		break;
+	}
+	if (req_ctx->decrypt) {
+		op.config |= CFG_DIR_DEC;
+		memcpy(cpg->sram + SRAM_DATA_KEY_P, ctx->aes_dec_key,
+				AES_KEY_LEN);
+	} else {
+		op.config |= CFG_DIR_ENC;
+		memcpy(cpg->sram + SRAM_DATA_KEY_P, ctx->aes_enc_key,
+				AES_KEY_LEN);
+	}
+
+	switch (ctx->key_len) {
+	case AES_KEYSIZE_128:
+		op.config |= CFG_AES_LEN_128;
+		break;
+	case AES_KEYSIZE_192:
+		op.config |= CFG_AES_LEN_192;
+		break;
+	case AES_KEYSIZE_256:
+		op.config |= CFG_AES_LEN_256;
+		break;
+	}
+	op.enc_p = ENC_P_SRC(SRAM_DATA_IN_START) |
+		ENC_P_DST(SRAM_DATA_OUT_START);
+	op.enc_key_p = SRAM_DATA_KEY_P;
+
+	setup_data_in(req);
+	op.enc_len = cpg->p.crypt_len;
+	memcpy(cpg->sram + SRAM_CONFIG, &op,
+			sizeof(struct sec_accel_config));
+
+	writel(SRAM_CONFIG, cpg->reg + SEC_ACCEL_DESC_P0);
+	/* GO */
+	writel(SEC_CMD_EN_SEC_ACCL0, cpg->reg + SEC_ACCEL_CMD);
+
+	/*
+	 * XXX: add timer if the interrupt does not occur for some mystery
+	 * reason
+	 */
+}
+
+static void mv_crypto_algo_completion(void)
+{
+	struct ablkcipher_request *req = cpg->cur_req;
+	struct mv_req_ctx *req_ctx = ablkcipher_request_ctx(req);
+
+	if (req_ctx->op != COP_AES_CBC)
+		return ;
+
+	memcpy(req->info, cpg->sram + SRAM_DATA_IV_BUF, 16);
+}
+
+static void dequeue_complete_req(void)
+{
+	struct ablkcipher_request *req = cpg->cur_req;
+	void *buf;
+	int ret;
+
+	cpg->p.total_req_bytes += cpg->p.crypt_len;
+	do {
+		int dst_copy;
+
+		if (!cpg->p.sg_dst_left) {
+			ret = sg_miter_next(&cpg->p.dst_sg_it);
+			BUG_ON(!ret);
+			cpg->p.sg_dst_left = cpg->p.dst_sg_it.length;
+			cpg->p.dst_start = 0;
+		}
+
+		buf = cpg->p.dst_sg_it.addr;
+		buf += cpg->p.dst_start;
+
+		dst_copy = min(cpg->p.crypt_len, cpg->p.sg_dst_left);
+
+		memcpy(buf, cpg->sram + SRAM_DATA_OUT_START, dst_copy);
+
+		cpg->p.sg_dst_left -= dst_copy;
+		cpg->p.crypt_len -= dst_copy;
+		cpg->p.dst_start += dst_copy;
+	} while (cpg->p.crypt_len > 0);
+
+	BUG_ON(cpg->eng_st != ENGINE_W_DEQUEUE);
+	if (cpg->p.total_req_bytes < req->nbytes) {
+		/* process next scatter list entry */
+		cpg->eng_st = ENGINE_BUSY;
+		mv_process_current_q(0);
+	} else {
+		sg_miter_stop(&cpg->p.src_sg_it);
+		sg_miter_stop(&cpg->p.dst_sg_it);
+		mv_crypto_algo_completion();
+		cpg->eng_st = ENGINE_IDLE;
+		req->base.complete(&req->base, 0);
+	}
+}
+
+static int count_sgs(struct scatterlist *sl, unsigned int total_bytes)
+{
+	int i = 0;
+
+	do {
+		total_bytes -= sl[i].length;
+		i++;
+
+	} while (total_bytes > 0);
+
+	return i;
+}
+
+static void mv_enqueue_new_req(struct ablkcipher_request *req)
+{
+	int num_sgs;
+
+	cpg->cur_req = req;
+	memset(&cpg->p, 0, sizeof(struct req_progress));
+
+	num_sgs = count_sgs(req->src, req->nbytes);
+	sg_miter_start(&cpg->p.src_sg_it, req->src, num_sgs, SG_MITER_FROM_SG);
+
+	num_sgs = count_sgs(req->dst, req->nbytes);
+	sg_miter_start(&cpg->p.dst_sg_it, req->dst, num_sgs, SG_MITER_TO_SG);
+	mv_process_current_q(1);
+}
+
+static int queue_manag(void *data)
+{
+	cpg->eng_st = ENGINE_IDLE;
+	do {
+		struct ablkcipher_request *req;
+		struct crypto_async_request *async_req = NULL;
+		struct crypto_async_request *backlog;
+
+		__set_current_state(TASK_INTERRUPTIBLE);
+
+		if (cpg->eng_st == ENGINE_W_DEQUEUE)
+			dequeue_complete_req();
+
+		spin_lock_irq(&cpg->lock);
+		if (cpg->eng_st == ENGINE_IDLE) {
+			backlog = crypto_get_backlog(&cpg->queue);
+			async_req = crypto_dequeue_request(&cpg->queue);
+			if (async_req) {
+				BUG_ON(cpg->eng_st != ENGINE_IDLE);
+				cpg->eng_st = ENGINE_BUSY;
+			}
+		}
+		spin_unlock_irq(&cpg->lock);
+
+		if (backlog) {
+			backlog->complete(backlog, -EINPROGRESS);
+			backlog = NULL;
+		}
+
+		if (async_req) {
+			req = container_of(async_req,
+					struct ablkcipher_request, base);
+			mv_enqueue_new_req(req);
+			async_req = NULL;
+		}
+
+		schedule();
+
+	} while (!kthread_should_stop());
+	return 0;
+}
+
+static int mv_handle_req(struct ablkcipher_request *req)
+{
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&cpg->lock, flags);
+	ret = ablkcipher_enqueue_request(&cpg->queue, req);
+	spin_unlock_irqrestore(&cpg->lock, flags);
+	wake_up_process(cpg->queue_th);
+	return ret;
+}
+
+static int mv_enc_aes_ecb(struct ablkcipher_request *req)
+{
+	struct mv_req_ctx *req_ctx = ablkcipher_request_ctx(req);
+
+	req_ctx->op = COP_AES_ECB;
+	req_ctx->decrypt = 0;
+
+	return mv_handle_req(req);
+}
+
+static int mv_dec_aes_ecb(struct ablkcipher_request *req)
+{
+	struct mv_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
+	struct mv_req_ctx *req_ctx = ablkcipher_request_ctx(req);
+
+	req_ctx->op = COP_AES_ECB;
+	req_ctx->decrypt = 1;
+
+	compute_aes_dec_key(ctx);
+	return mv_handle_req(req);
+}
+
+static int mv_enc_aes_cbc(struct ablkcipher_request *req)
+{
+	struct mv_req_ctx *req_ctx = ablkcipher_request_ctx(req);
+
+	req_ctx->op = COP_AES_CBC;
+	req_ctx->decrypt = 0;
+
+	return mv_handle_req(req);
+}
+
+static int mv_dec_aes_cbc(struct ablkcipher_request *req)
+{
+	struct mv_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
+	struct mv_req_ctx *req_ctx = ablkcipher_request_ctx(req);
+
+	req_ctx->op = COP_AES_CBC;
+	req_ctx->decrypt = 1;
+
+	compute_aes_dec_key(ctx);
+	return mv_handle_req(req);
+}
+
+static int mv_cra_init(struct crypto_tfm *tfm)
+{
+	tfm->crt_ablkcipher.reqsize = sizeof(struct mv_req_ctx);
+	return 0;
+}
+
+irqreturn_t crypto_int(int irq, void *priv)
+{
+	u32 val;
+
+	val = readl(cpg->reg + SEC_ACCEL_INT_STATUS);
+	if (!(val & SEC_INT_ACCEL0_DONE))
+		return IRQ_NONE;
+
+	val &= ~SEC_INT_ACCEL0_DONE;
+	writel(val, cpg->reg + FPGA_INT_STATUS);
+	writel(val, cpg->reg + SEC_ACCEL_INT_STATUS);
+	BUG_ON(cpg->eng_st != ENGINE_BUSY);
+	cpg->eng_st = ENGINE_W_DEQUEUE;
+	wake_up_process(cpg->queue_th);
+	return IRQ_HANDLED;
+}
+
+struct crypto_alg mv_aes_alg_ecb = {
+	.cra_name		= "ecb(aes)",
+	.cra_driver_name	= "mv-ecb-aes",
+	.cra_priority	= 300,
+	.cra_flags	= CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
+	.cra_blocksize	= 16,
+	.cra_ctxsize	= sizeof(struct mv_ctx),
+	.cra_alignmask	= 0,
+	.cra_type	= &crypto_ablkcipher_type,
+	.cra_module	= THIS_MODULE,
+	.cra_init	= mv_cra_init,
+	.cra_u		= {
+		.ablkcipher = {
+			.min_keysize	=	AES_MIN_KEY_SIZE,
+			.max_keysize	=	AES_MAX_KEY_SIZE,
+			.setkey		=	mv_setkey_aes,
+			.encrypt	=	mv_enc_aes_ecb,
+			.decrypt	=	mv_dec_aes_ecb,
+		},
+	},
+};
+
+struct crypto_alg mv_aes_alg_cbc = {
+	.cra_name		= "cbc(aes)",
+	.cra_driver_name	= "mv-cbc-aes",
+	.cra_priority	= 300,
+	.cra_flags	= CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
+	.cra_blocksize	= AES_BLOCK_SIZE,
+	.cra_ctxsize	= sizeof(struct mv_ctx),
+	.cra_alignmask	= 0,
+	.cra_type	= &crypto_ablkcipher_type,
+	.cra_module	= THIS_MODULE,
+	.cra_init	= mv_cra_init,
+	.cra_u		= {
+		.ablkcipher = {
+			.ivsize		=	AES_BLOCK_SIZE,
+			.min_keysize	=	AES_MIN_KEY_SIZE,
+			.max_keysize	=	AES_MAX_KEY_SIZE,
+			.setkey		=	mv_setkey_aes,
+			.encrypt	=	mv_enc_aes_cbc,
+			.decrypt	=	mv_dec_aes_cbc,
+		},
+	},
+};
+
+static int mv_probe(struct platform_device *pdev)
+{
+	struct crypto_priv *cp;
+	struct resource *res;
+	int irq;
+	int ret;
+
+	if (cpg) {
+		printk(KERN_ERR "Second crypto dev?\n");
+		return -EEXIST;
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "regs");
+	if (!res)
+		return -ENXIO;
+
+	cp = kzalloc(sizeof(*cp), GFP_KERNEL);
+	if (!cp)
+		return -ENOMEM;
+
+	spin_lock_init(&cp->lock);
+	crypto_init_queue(&cp->queue, 50);
+	cp->reg = ioremap(res->start, res->end - res->start + 1);
+	if (!cp->reg) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "sram");
+	if (!res) {
+		ret = -ENXIO;
+		goto err_unmap_reg;
+	}
+	cp->sram_size = res->end - res->start + 1;
+	cp->max_req_size = cp->sram_size - SRAM_CFG_SPACE;
+	cp->sram = ioremap(res->start, cp->sram_size);
+	if (!cp->sram) {
+		ret = -ENOMEM;
+		goto err_unmap_reg;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0 || irq == NO_IRQ) {
+		ret = irq;
+		goto err_unmap_sram;
+	}
+	cp->irq = irq;
+
+	platform_set_drvdata(pdev, cp);
+	cpg = cp;
+
+	cp->queue_th = kthread_run(queue_manag, cp, "mv_crypto");
+	if (IS_ERR(cp->queue_th)) {
+		ret = PTR_ERR(cp->queue_th);
+		goto err_thread;
+	}
+
+	ret = request_irq(irq, crypto_int, IRQF_DISABLED, dev_name(&pdev->dev),
+			cp);
+	if (ret)
+		goto err_unmap_sram;
+
+	writel(SEC_INT_ACCEL0_DONE, cpg->reg + SEC_ACCEL_INT_MASK);
+	writel(SEC_CFG_STOP_DIG_ERR, cpg->reg + SEC_ACCEL_CFG);
+
+	ret = crypto_register_alg(&mv_aes_alg_ecb);
+	if (ret)
+		goto err_reg;
+
+	ret = crypto_register_alg(&mv_aes_alg_cbc);
+	if (ret)
+		goto err_unreg_ecb;
+	return 0;
+err_unreg_ecb:
+	crypto_unregister_alg(&mv_aes_alg_ecb);
+err_thread:
+	free_irq(irq, cp);
+err_reg:
+	kthread_stop(cp->queue_th);
+err_unmap_sram:
+	iounmap(cp->sram);
+err_unmap_reg:
+	iounmap(cp->reg);
+err:
+	kfree(cp);
+	cpg = NULL;
+	platform_set_drvdata(pdev, NULL);
+	return ret;
+}
+
+static int mv_remove(struct platform_device *pdev)
+{
+	struct crypto_priv *cp = platform_get_drvdata(pdev);
+
+	crypto_unregister_alg(&mv_aes_alg_ecb);
+	crypto_unregister_alg(&mv_aes_alg_cbc);
+	kthread_stop(cp->queue_th);
+	free_irq(cp->irq, cp);
+	memset(cp->sram, 0, cp->sram_size);
+	iounmap(cp->sram);
+	iounmap(cp->reg);
+	kfree(cp);
+	cpg = NULL;
+	return 0;
+}
+
+static struct platform_driver marvell_crypto = {
+	.probe		= mv_probe,
+	.remove		= mv_remove,
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= "mv_crypto",
+	},
+};
+MODULE_ALIAS("platform:mv_crypto");
+
+static int __init mv_crypto_init(void)
+{
+	return platform_driver_register(&marvell_crypto);
+}
+module_init(mv_crypto_init);
+
+static void __exit mv_crypto_exit(void)
+{
+	platform_driver_unregister(&marvell_crypto);
+}
+module_exit(mv_crypto_exit);
+
+MODULE_AUTHOR("Sebastian Andrzej Siewior <sebastian@breakpoint.cc>");
+MODULE_DESCRIPTION("Support for Marvell's cryptographic engine");
+MODULE_LICENSE("GPL");