1 files changed, 487 insertions, 0 deletions

diff --git a/drivers/crypto/stm32/stm32-crc32.c b/drivers/crypto/stm32/stm32-crc32.c
new file mode 100644
index 000000000..90a920e7f
--- /dev/null
+++ b/drivers/crypto/stm32/stm32-crc32.c
@@ -0,0 +1,487 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) STMicroelectronics SA 2017
+ * Author: Fabien Dessenne <fabien.dessenne@st.com>
+ */
+
+#include <linux/bitrev.h>
+#include <linux/clk.h>
+#include <linux/crc32.h>
+#include <linux/crc32poly.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+#include <crypto/internal/hash.h>
+
+#include <asm/unaligned.h>
+
+#define DRIVER_NAME             "stm32-crc32"
+#define CHKSUM_DIGEST_SIZE      4
+#define CHKSUM_BLOCK_SIZE       1
+
+/* Registers */
+#define CRC_DR                  0x00000000
+#define CRC_CR                  0x00000008
+#define CRC_INIT                0x00000010
+#define CRC_POL                 0x00000014
+
+/* Registers values */
+#define CRC_CR_RESET            BIT(0)
+#define CRC_CR_REV_IN_WORD      (BIT(6) | BIT(5))
+#define CRC_CR_REV_IN_BYTE      BIT(5)
+#define CRC_CR_REV_OUT          BIT(7)
+#define CRC32C_INIT_DEFAULT     0xFFFFFFFF
+
+#define CRC_AUTOSUSPEND_DELAY	50
+
+static unsigned int burst_size;
+module_param(burst_size, uint, 0644);
+MODULE_PARM_DESC(burst_size, "Select burst byte size (0 unlimited)");
+
+struct stm32_crc {
+	struct list_head list;
+	struct device    *dev;
+	void __iomem     *regs;
+	struct clk       *clk;
+	spinlock_t       lock;
+};
+
+struct stm32_crc_list {
+	struct list_head dev_list;
+	spinlock_t       lock; /* protect dev_list */
+};
+
+static struct stm32_crc_list crc_list = {
+	.dev_list = LIST_HEAD_INIT(crc_list.dev_list),
+	.lock     = __SPIN_LOCK_UNLOCKED(crc_list.lock),
+};
+
+struct stm32_crc_ctx {
+	u32 key;
+	u32 poly;
+};
+
+struct stm32_crc_desc_ctx {
+	u32    partial; /* crc32c: partial in first 4 bytes of that struct */
+};
+
+static int stm32_crc32_cra_init(struct crypto_tfm *tfm)
+{
+	struct stm32_crc_ctx *mctx = crypto_tfm_ctx(tfm);
+
+	mctx->key = 0;
+	mctx->poly = CRC32_POLY_LE;
+	return 0;
+}
+
+static int stm32_crc32c_cra_init(struct crypto_tfm *tfm)
+{
+	struct stm32_crc_ctx *mctx = crypto_tfm_ctx(tfm);
+
+	mctx->key = CRC32C_INIT_DEFAULT;
+	mctx->poly = CRC32C_POLY_LE;
+	return 0;
+}
+
+static int stm32_crc_setkey(struct crypto_shash *tfm, const u8 *key,
+			    unsigned int keylen)
+{
+	struct stm32_crc_ctx *mctx = crypto_shash_ctx(tfm);
+
+	if (keylen != sizeof(u32))
+		return -EINVAL;
+
+	mctx->key = get_unaligned_le32(key);
+	return 0;
+}
+
+static struct stm32_crc *stm32_crc_get_next_crc(void)
+{
+	struct stm32_crc *crc;
+
+	spin_lock_bh(&crc_list.lock);
+	crc = list_first_entry(&crc_list.dev_list, struct stm32_crc, list);
+	if (crc)
+		list_move_tail(&crc->list, &crc_list.dev_list);
+	spin_unlock_bh(&crc_list.lock);
+
+	return crc;
+}
+
+static int stm32_crc_init(struct shash_desc *desc)
+{
+	struct stm32_crc_desc_ctx *ctx = shash_desc_ctx(desc);
+	struct stm32_crc_ctx *mctx = crypto_shash_ctx(desc->tfm);
+	struct stm32_crc *crc;
+	unsigned long flags;
+
+	crc = stm32_crc_get_next_crc();
+	if (!crc)
+		return -ENODEV;
+
+	pm_runtime_get_sync(crc->dev);
+
+	spin_lock_irqsave(&crc->lock, flags);
+
+	/* Reset, set key, poly and configure in bit reverse mode */
+	writel_relaxed(bitrev32(mctx->key), crc->regs + CRC_INIT);
+	writel_relaxed(bitrev32(mctx->poly), crc->regs + CRC_POL);
+	writel_relaxed(CRC_CR_RESET | CRC_CR_REV_IN_WORD | CRC_CR_REV_OUT,
+		       crc->regs + CRC_CR);
+
+	/* Store partial result */
+	ctx->partial = readl_relaxed(crc->regs + CRC_DR);
+
+	spin_unlock_irqrestore(&crc->lock, flags);
+
+	pm_runtime_mark_last_busy(crc->dev);
+	pm_runtime_put_autosuspend(crc->dev);
+
+	return 0;
+}
+
+static int burst_update(struct shash_desc *desc, const u8 *d8,
+			size_t length)
+{
+	struct stm32_crc_desc_ctx *ctx = shash_desc_ctx(desc);
+	struct stm32_crc_ctx *mctx = crypto_shash_ctx(desc->tfm);
+	struct stm32_crc *crc;
+
+	crc = stm32_crc_get_next_crc();
+	if (!crc)
+		return -ENODEV;
+
+	pm_runtime_get_sync(crc->dev);
+
+	if (!spin_trylock(&crc->lock)) {
+		/* Hardware is busy, calculate crc32 by software */
+		if (mctx->poly == CRC32_POLY_LE)
+			ctx->partial = crc32_le(ctx->partial, d8, length);
+		else
+			ctx->partial = __crc32c_le(ctx->partial, d8, length);
+
+		goto pm_out;
+	}
+
+	/*
+	 * Restore previously calculated CRC for this context as init value
+	 * Restore polynomial configuration
+	 * Configure in register for word input data,
+	 * Configure out register in reversed bit mode data.
+	 */
+	writel_relaxed(bitrev32(ctx->partial), crc->regs + CRC_INIT);
+	writel_relaxed(bitrev32(mctx->poly), crc->regs + CRC_POL);
+	writel_relaxed(CRC_CR_RESET | CRC_CR_REV_IN_WORD | CRC_CR_REV_OUT,
+		       crc->regs + CRC_CR);
+
+	if (d8 != PTR_ALIGN(d8, sizeof(u32))) {
+		/* Configure for byte data */
+		writel_relaxed(CRC_CR_REV_IN_BYTE | CRC_CR_REV_OUT,
+			       crc->regs + CRC_CR);
+		while (d8 != PTR_ALIGN(d8, sizeof(u32)) && length) {
+			writeb_relaxed(*d8++, crc->regs + CRC_DR);
+			length--;
+		}
+		/* Configure for word data */
+		writel_relaxed(CRC_CR_REV_IN_WORD | CRC_CR_REV_OUT,
+			       crc->regs + CRC_CR);
+	}
+
+	for (; length >= sizeof(u32); d8 += sizeof(u32), length -= sizeof(u32))
+		writel_relaxed(*((u32 *)d8), crc->regs + CRC_DR);
+
+	if (length) {
+		/* Configure for byte data */
+		writel_relaxed(CRC_CR_REV_IN_BYTE | CRC_CR_REV_OUT,
+			       crc->regs + CRC_CR);
+		while (length--)
+			writeb_relaxed(*d8++, crc->regs + CRC_DR);
+	}
+
+	/* Store partial result */
+	ctx->partial = readl_relaxed(crc->regs + CRC_DR);
+
+	spin_unlock(&crc->lock);
+
+pm_out:
+	pm_runtime_mark_last_busy(crc->dev);
+	pm_runtime_put_autosuspend(crc->dev);
+
+	return 0;
+}
+
+static int stm32_crc_update(struct shash_desc *desc, const u8 *d8,
+			    unsigned int length)
+{
+	const unsigned int burst_sz = burst_size;
+	unsigned int rem_sz;
+	const u8 *cur;
+	size_t size;
+	int ret;
+
+	if (!burst_sz)
+		return burst_update(desc, d8, length);
+
+	/* Digest first bytes not 32bit aligned at first pass in the loop */
+	size = min_t(size_t, length, burst_sz + (size_t)d8 -
+				     ALIGN_DOWN((size_t)d8, sizeof(u32)));
+	for (rem_sz = length, cur = d8; rem_sz;
+	     rem_sz -= size, cur += size, size = min(rem_sz, burst_sz)) {
+		ret = burst_update(desc, cur, size);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int stm32_crc_final(struct shash_desc *desc, u8 *out)
+{
+	struct stm32_crc_desc_ctx *ctx = shash_desc_ctx(desc);
+	struct stm32_crc_ctx *mctx = crypto_shash_ctx(desc->tfm);
+
+	/* Send computed CRC */
+	put_unaligned_le32(mctx->poly == CRC32C_POLY_LE ?
+			   ~ctx->partial : ctx->partial, out);
+
+	return 0;
+}
+
+static int stm32_crc_finup(struct shash_desc *desc, const u8 *data,
+			   unsigned int length, u8 *out)
+{
+	return stm32_crc_update(desc, data, length) ?:
+	       stm32_crc_final(desc, out);
+}
+
+static int stm32_crc_digest(struct shash_desc *desc, const u8 *data,
+			    unsigned int length, u8 *out)
+{
+	return stm32_crc_init(desc) ?: stm32_crc_finup(desc, data, length, out);
+}
+
+static unsigned int refcnt;
+static DEFINE_MUTEX(refcnt_lock);
+static struct shash_alg algs[] = {
+	/* CRC-32 */
+	{
+		.setkey         = stm32_crc_setkey,
+		.init           = stm32_crc_init,
+		.update         = stm32_crc_update,
+		.final          = stm32_crc_final,
+		.finup          = stm32_crc_finup,
+		.digest         = stm32_crc_digest,
+		.descsize       = sizeof(struct stm32_crc_desc_ctx),
+		.digestsize     = CHKSUM_DIGEST_SIZE,
+		.base           = {
+			.cra_name               = "crc32",
+			.cra_driver_name        = "stm32-crc32-crc32",
+			.cra_priority           = 200,
+			.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,
+			.cra_blocksize          = CHKSUM_BLOCK_SIZE,
+			.cra_alignmask          = 3,
+			.cra_ctxsize            = sizeof(struct stm32_crc_ctx),
+			.cra_module             = THIS_MODULE,
+			.cra_init               = stm32_crc32_cra_init,
+		}
+	},
+	/* CRC-32Castagnoli */
+	{
+		.setkey         = stm32_crc_setkey,
+		.init           = stm32_crc_init,
+		.update         = stm32_crc_update,
+		.final          = stm32_crc_final,
+		.finup          = stm32_crc_finup,
+		.digest         = stm32_crc_digest,
+		.descsize       = sizeof(struct stm32_crc_desc_ctx),
+		.digestsize     = CHKSUM_DIGEST_SIZE,
+		.base           = {
+			.cra_name               = "crc32c",
+			.cra_driver_name        = "stm32-crc32-crc32c",
+			.cra_priority           = 200,
+			.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,
+			.cra_blocksize          = CHKSUM_BLOCK_SIZE,
+			.cra_alignmask          = 3,
+			.cra_ctxsize            = sizeof(struct stm32_crc_ctx),
+			.cra_module             = THIS_MODULE,
+			.cra_init               = stm32_crc32c_cra_init,
+		}
+	}
+};
+
+static int stm32_crc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct stm32_crc *crc;
+	int ret;
+
+	crc = devm_kzalloc(dev, sizeof(*crc), GFP_KERNEL);
+	if (!crc)
+		return -ENOMEM;
+
+	crc->dev = dev;
+
+	crc->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(crc->regs)) {
+		dev_err(dev, "Cannot map CRC IO\n");
+		return PTR_ERR(crc->regs);
+	}
+
+	crc->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(crc->clk)) {
+		dev_err(dev, "Could not get clock\n");
+		return PTR_ERR(crc->clk);
+	}
+
+	ret = clk_prepare_enable(crc->clk);
+	if (ret) {
+		dev_err(crc->dev, "Failed to enable clock\n");
+		return ret;
+	}
+
+	pm_runtime_set_autosuspend_delay(dev, CRC_AUTOSUSPEND_DELAY);
+	pm_runtime_use_autosuspend(dev);
+
+	pm_runtime_get_noresume(dev);
+	pm_runtime_set_active(dev);
+	pm_runtime_irq_safe(dev);
+	pm_runtime_enable(dev);
+
+	spin_lock_init(&crc->lock);
+
+	platform_set_drvdata(pdev, crc);
+
+	spin_lock(&crc_list.lock);
+	list_add(&crc->list, &crc_list.dev_list);
+	spin_unlock(&crc_list.lock);
+
+	mutex_lock(&refcnt_lock);
+	if (!refcnt) {
+		ret = crypto_register_shashes(algs, ARRAY_SIZE(algs));
+		if (ret) {
+			mutex_unlock(&refcnt_lock);
+			dev_err(dev, "Failed to register\n");
+			clk_disable_unprepare(crc->clk);
+			return ret;
+		}
+	}
+	refcnt++;
+	mutex_unlock(&refcnt_lock);
+
+	dev_info(dev, "Initialized\n");
+
+	pm_runtime_put_sync(dev);
+
+	return 0;
+}
+
+static int stm32_crc_remove(struct platform_device *pdev)
+{
+	struct stm32_crc *crc = platform_get_drvdata(pdev);
+	int ret = pm_runtime_get_sync(crc->dev);
+
+	if (ret < 0) {
+		pm_runtime_put_noidle(crc->dev);
+		return ret;
+	}
+
+	spin_lock(&crc_list.lock);
+	list_del(&crc->list);
+	spin_unlock(&crc_list.lock);
+
+	mutex_lock(&refcnt_lock);
+	if (!--refcnt)
+		crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
+	mutex_unlock(&refcnt_lock);
+
+	pm_runtime_disable(crc->dev);
+	pm_runtime_put_noidle(crc->dev);
+
+	clk_disable_unprepare(crc->clk);
+
+	return 0;
+}
+
+static int __maybe_unused stm32_crc_suspend(struct device *dev)
+{
+	struct stm32_crc *crc = dev_get_drvdata(dev);
+	int ret;
+
+	ret = pm_runtime_force_suspend(dev);
+	if (ret)
+		return ret;
+
+	clk_unprepare(crc->clk);
+
+	return 0;
+}
+
+static int __maybe_unused stm32_crc_resume(struct device *dev)
+{
+	struct stm32_crc *crc = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare(crc->clk);
+	if (ret) {
+		dev_err(crc->dev, "Failed to prepare clock\n");
+		return ret;
+	}
+
+	return pm_runtime_force_resume(dev);
+}
+
+static int __maybe_unused stm32_crc_runtime_suspend(struct device *dev)
+{
+	struct stm32_crc *crc = dev_get_drvdata(dev);
+
+	clk_disable(crc->clk);
+
+	return 0;
+}
+
+static int __maybe_unused stm32_crc_runtime_resume(struct device *dev)
+{
+	struct stm32_crc *crc = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_enable(crc->clk);
+	if (ret) {
+		dev_err(crc->dev, "Failed to enable clock\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops stm32_crc_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(stm32_crc_suspend,
+				stm32_crc_resume)
+	SET_RUNTIME_PM_OPS(stm32_crc_runtime_suspend,
+			   stm32_crc_runtime_resume, NULL)
+};
+
+static const struct of_device_id stm32_dt_ids[] = {
+	{ .compatible = "st,stm32f7-crc", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, stm32_dt_ids);
+
+static struct platform_driver stm32_crc_driver = {
+	.probe  = stm32_crc_probe,
+	.remove = stm32_crc_remove,
+	.driver = {
+		.name           = DRIVER_NAME,
+		.pm		= &stm32_crc_pm_ops,
+		.of_match_table = stm32_dt_ids,
+	},
+};
+
+module_platform_driver(stm32_crc_driver);
+
+MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
+MODULE_DESCRIPTION("STMicrolectronics STM32 CRC32 hardware driver");
+MODULE_LICENSE("GPL");