crypto: marvell/cesa - add a new driver for Marvell's CESA

The existing mv_cesa driver supports some features of the CESA IP but is
quite limited, and reworking it to support new features (like involving the
TDMA engine to offload the CPU) is almost impossible.
This driver has been rewritten from scratch to take those new features into
account.

This commit introduce the base infrastructure allowing us to add support
for DMA optimization.
It also includes support for one hash (SHA1) and one cipher (AES)
algorithm, and enable those features on the Armada 370 SoC.

Other algorithms and platforms will be added later on.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 417 insertions, 0 deletions

diff --git a/drivers/crypto/marvell/cesa.c b/drivers/crypto/marvell/cesa.c
new file mode 100644
index 000000000000..76a694303839
--- /dev/null
+++ b/drivers/crypto/marvell/cesa.c
@@ -0,0 +1,417 @@
+/*
+ * Support for Marvell's Cryptographic Engine and Security Accelerator (CESA)
+ * that can be found on the following platform: Orion, Kirkwood, Armada. This
+ * driver supports the TDMA engine on platforms on which it is available.
+ *
+ * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
+ * Author: Arnaud Ebalard <arno@natisbad.org>
+ *
+ * This work is based on an initial version written by
+ * Sebastian Andrzej Siewior < sebastian at breakpoint dot cc >
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <linux/delay.h>
+#include <linux/genalloc.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kthread.h>
+#include <linux/mbus.h>
+#include <linux/platform_device.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/of_irq.h>
+
+#include "cesa.h"
+
+struct mv_cesa_dev *cesa_dev;
+
+static void mv_cesa_dequeue_req_unlocked(struct mv_cesa_engine *engine)
+{
+	struct crypto_async_request *req, *backlog;
+	struct mv_cesa_ctx *ctx;
+
+	spin_lock_bh(&cesa_dev->lock);
+	backlog = crypto_get_backlog(&cesa_dev->queue);
+	req = crypto_dequeue_request(&cesa_dev->queue);
+	engine->req = req;
+	spin_unlock_bh(&cesa_dev->lock);
+
+	if (!req)
+		return;
+
+	if (backlog)
+		backlog->complete(backlog, -EINPROGRESS);
+
+	ctx = crypto_tfm_ctx(req->tfm);
+	ctx->ops->prepare(req, engine);
+	ctx->ops->step(req);
+}
+
+static irqreturn_t mv_cesa_int(int irq, void *priv)
+{
+	struct mv_cesa_engine *engine = priv;
+	struct crypto_async_request *req;
+	struct mv_cesa_ctx *ctx;
+	u32 status, mask;
+	irqreturn_t ret = IRQ_NONE;
+
+	while (true) {
+		int res;
+
+		mask = mv_cesa_get_int_mask(engine);
+		status = readl(engine->regs + CESA_SA_INT_STATUS);
+
+		if (!(status & mask))
+			break;
+
+		/*
+		 * TODO: avoid clearing the FPGA_INT_STATUS if this not
+		 * relevant on some platforms.
+		 */
+		writel(~status, engine->regs + CESA_SA_FPGA_INT_STATUS);
+		writel(~status, engine->regs + CESA_SA_INT_STATUS);
+
+		ret = IRQ_HANDLED;
+		spin_lock_bh(&engine->lock);
+		req = engine->req;
+		spin_unlock_bh(&engine->lock);
+		if (req) {
+			ctx = crypto_tfm_ctx(req->tfm);
+			res = ctx->ops->process(req, status & mask);
+			if (res != -EINPROGRESS) {
+				spin_lock_bh(&engine->lock);
+				engine->req = NULL;
+				mv_cesa_dequeue_req_unlocked(engine);
+				spin_unlock_bh(&engine->lock);
+				ctx->ops->cleanup(req);
+				local_bh_disable();
+				req->complete(req, res);
+				local_bh_enable();
+			} else {
+				ctx->ops->step(req);
+			}
+		}
+	}
+
+	return ret;
+}
+
+int mv_cesa_queue_req(struct crypto_async_request *req)
+{
+	int ret;
+	int i;
+
+	spin_lock_bh(&cesa_dev->lock);
+	ret = crypto_enqueue_request(&cesa_dev->queue, req);
+	spin_unlock_bh(&cesa_dev->lock);
+
+	if (ret != -EINPROGRESS)
+		return ret;
+
+	for (i = 0; i < cesa_dev->caps->nengines; i++) {
+		spin_lock_bh(&cesa_dev->engines[i].lock);
+		if (!cesa_dev->engines[i].req)
+			mv_cesa_dequeue_req_unlocked(&cesa_dev->engines[i]);
+		spin_unlock_bh(&cesa_dev->engines[i].lock);
+	}
+
+	return -EINPROGRESS;
+}
+
+static int mv_cesa_add_algs(struct mv_cesa_dev *cesa)
+{
+	int ret;
+	int i, j;
+
+	for (i = 0; i < cesa->caps->ncipher_algs; i++) {
+		ret = crypto_register_alg(cesa->caps->cipher_algs[i]);
+		if (ret)
+			goto err_unregister_crypto;
+	}
+
+	for (i = 0; i < cesa->caps->nahash_algs; i++) {
+		ret = crypto_register_ahash(cesa->caps->ahash_algs[i]);
+		if (ret)
+			goto err_unregister_ahash;
+	}
+
+	return 0;
+
+err_unregister_ahash:
+	for (j = 0; j < i; j++)
+		crypto_unregister_ahash(cesa->caps->ahash_algs[j]);
+	i = cesa->caps->ncipher_algs;
+
+err_unregister_crypto:
+	for (j = 0; j < i; j++)
+		crypto_unregister_alg(cesa->caps->cipher_algs[j]);
+
+	return ret;
+}
+
+static void mv_cesa_remove_algs(struct mv_cesa_dev *cesa)
+{
+	int i;
+
+	for (i = 0; i < cesa->caps->nahash_algs; i++)
+		crypto_unregister_ahash(cesa->caps->ahash_algs[i]);
+
+	for (i = 0; i < cesa->caps->ncipher_algs; i++)
+		crypto_unregister_alg(cesa->caps->cipher_algs[i]);
+}
+
+static struct crypto_alg *armada_370_cipher_algs[] = {
+	&mv_cesa_ecb_aes_alg,
+	&mv_cesa_cbc_aes_alg,
+};
+
+static struct ahash_alg *armada_370_ahash_algs[] = {
+	&mv_sha1_alg,
+	&mv_ahmac_sha1_alg,
+};
+
+static const struct mv_cesa_caps armada_370_caps = {
+	.nengines = 1,
+	.cipher_algs = armada_370_cipher_algs,
+	.ncipher_algs = ARRAY_SIZE(armada_370_cipher_algs),
+	.ahash_algs = armada_370_ahash_algs,
+	.nahash_algs = ARRAY_SIZE(armada_370_ahash_algs),
+};
+
+static const struct of_device_id mv_cesa_of_match_table[] = {
+	{ .compatible = "marvell,armada-370-crypto", .data = &armada_370_caps },
+	{}
+};
+MODULE_DEVICE_TABLE(of, mv_cesa_of_match_table);
+
+static int mv_cesa_get_sram(struct platform_device *pdev, int idx)
+{
+	struct mv_cesa_dev *cesa = platform_get_drvdata(pdev);
+	struct mv_cesa_engine *engine = &cesa->engines[idx];
+	const char *res_name = "sram";
+	struct resource *res;
+
+	engine->pool = of_get_named_gen_pool(cesa->dev->of_node,
+					     "marvell,crypto-srams",
+					     idx);
+	if (engine->pool) {
+		engine->sram = gen_pool_dma_alloc(engine->pool,
+						  cesa->sram_size,
+						  &engine->sram_dma);
+		if (engine->sram)
+			return 0;
+
+		engine->pool = NULL;
+		return -ENOMEM;
+	}
+
+	if (cesa->caps->nengines > 1) {
+		if (!idx)
+			res_name = "sram0";
+		else
+			res_name = "sram1";
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+					   res_name);
+	if (!res || resource_size(res) < cesa->sram_size)
+		return -EINVAL;
+
+	engine->sram = devm_ioremap_resource(cesa->dev, res);
+	if (IS_ERR(engine->sram))
+		return PTR_ERR(engine->sram);
+
+	engine->sram_dma = phys_to_dma(cesa->dev,
+				       (phys_addr_t)res->start);
+
+	return 0;
+}
+
+static void mv_cesa_put_sram(struct platform_device *pdev, int idx)
+{
+	struct mv_cesa_dev *cesa = platform_get_drvdata(pdev);
+	struct mv_cesa_engine *engine = &cesa->engines[idx];
+
+	if (!engine->pool)
+		return;
+
+	gen_pool_free(engine->pool, (unsigned long)engine->sram,
+		      cesa->sram_size);
+}
+
+static int mv_cesa_probe(struct platform_device *pdev)
+{
+	const struct mv_cesa_caps *caps = NULL;
+	const struct mbus_dram_target_info *dram;
+	const struct of_device_id *match;
+	struct device *dev = &pdev->dev;
+	struct mv_cesa_dev *cesa;
+	struct mv_cesa_engine *engines;
+	struct resource *res;
+	int irq, ret, i;
+	u32 sram_size;
+
+	if (cesa_dev) {
+		dev_err(&pdev->dev, "Only one CESA device authorized\n");
+		return -EEXIST;
+	}
+
+	if (!dev->of_node)
+		return -ENOTSUPP;
+
+	match = of_match_node(mv_cesa_of_match_table, dev->of_node);
+	if (!match || !match->data)
+		return -ENOTSUPP;
+
+	caps = match->data;
+
+	cesa = devm_kzalloc(dev, sizeof(*cesa), GFP_KERNEL);
+	if (!cesa)
+		return -ENOMEM;
+
+	cesa->caps = caps;
+	cesa->dev = dev;
+
+	sram_size = CESA_SA_DEFAULT_SRAM_SIZE;
+	of_property_read_u32(cesa->dev->of_node, "marvell,crypto-sram-size",
+			     &sram_size);
+	if (sram_size < CESA_SA_MIN_SRAM_SIZE)
+		sram_size = CESA_SA_MIN_SRAM_SIZE;
+
+	cesa->sram_size = sram_size;
+	cesa->engines = devm_kzalloc(dev, caps->nengines * sizeof(*engines),
+				     GFP_KERNEL);
+	if (!cesa->engines)
+		return -ENOMEM;
+
+	spin_lock_init(&cesa->lock);
+	crypto_init_queue(&cesa->queue, 50);
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "regs");
+	cesa->regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(cesa->regs))
+		return -ENOMEM;
+
+	dram = mv_mbus_dram_info_nooverlap();
+
+	platform_set_drvdata(pdev, cesa);
+
+	for (i = 0; i < caps->nengines; i++) {
+		struct mv_cesa_engine *engine = &cesa->engines[i];
+		char res_name[7];
+
+		engine->id = i;
+		spin_lock_init(&engine->lock);
+
+		ret = mv_cesa_get_sram(pdev, i);
+		if (ret)
+			goto err_cleanup;
+
+		irq = platform_get_irq(pdev, i);
+		if (irq < 0) {
+			ret = irq;
+			goto err_cleanup;
+		}
+
+		/*
+		 * Not all platforms can gate the CESA clocks: do not complain
+		 * if the clock does not exist.
+		 */
+		snprintf(res_name, sizeof(res_name), "cesa%d", i);
+		engine->clk = devm_clk_get(dev, res_name);
+		if (IS_ERR(engine->clk)) {
+			engine->clk = devm_clk_get(dev, NULL);
+			if (IS_ERR(engine->clk))
+				engine->clk = NULL;
+		}
+
+		snprintf(res_name, sizeof(res_name), "cesaz%d", i);
+		engine->zclk = devm_clk_get(dev, res_name);
+		if (IS_ERR(engine->zclk))
+			engine->zclk = NULL;
+
+		ret = clk_prepare_enable(engine->clk);
+		if (ret)
+			goto err_cleanup;
+
+		ret = clk_prepare_enable(engine->zclk);
+		if (ret)
+			goto err_cleanup;
+
+		engine->regs = cesa->regs + CESA_ENGINE_OFF(i);
+
+		writel(0, cesa->engines[i].regs + CESA_SA_INT_STATUS);
+		writel(CESA_SA_CFG_STOP_DIG_ERR,
+		       cesa->engines[i].regs + CESA_SA_CFG);
+		writel(engine->sram_dma & CESA_SA_SRAM_MSK,
+		       cesa->engines[i].regs + CESA_SA_DESC_P0);
+
+		ret = devm_request_threaded_irq(dev, irq, NULL, mv_cesa_int,
+						IRQF_ONESHOT,
+						dev_name(&pdev->dev),
+						&cesa->engines[i]);
+		if (ret)
+			goto err_cleanup;
+	}
+
+	cesa_dev = cesa;
+
+	ret = mv_cesa_add_algs(cesa);
+	if (ret) {
+		cesa_dev = NULL;
+		goto err_cleanup;
+	}
+
+	dev_info(dev, "CESA device successfully registered\n");
+
+	return 0;
+
+err_cleanup:
+	for (i = 0; i < caps->nengines; i++) {
+		clk_disable_unprepare(cesa->engines[i].zclk);
+		clk_disable_unprepare(cesa->engines[i].clk);
+		mv_cesa_put_sram(pdev, i);
+	}
+
+	return ret;
+}
+
+static int mv_cesa_remove(struct platform_device *pdev)
+{
+	struct mv_cesa_dev *cesa = platform_get_drvdata(pdev);
+	int i;
+
+	mv_cesa_remove_algs(cesa);
+
+	for (i = 0; i < cesa->caps->nengines; i++) {
+		clk_disable_unprepare(cesa->engines[i].zclk);
+		clk_disable_unprepare(cesa->engines[i].clk);
+		mv_cesa_put_sram(pdev, i);
+	}
+
+	return 0;
+}
+
+static struct platform_driver marvell_cesa = {
+	.probe		= mv_cesa_probe,
+	.remove		= mv_cesa_remove,
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= "marvell-cesa",
+		.of_match_table = mv_cesa_of_match_table,
+	},
+};
+module_platform_driver(marvell_cesa);
+
+MODULE_ALIAS("platform:mv_crypto");
+MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
+MODULE_AUTHOR("Arnaud Ebalard <arno@natisbad.org>");
+MODULE_DESCRIPTION("Support for Marvell's cryptographic engine");
+MODULE_LICENSE("GPL v2");