1 files changed, 368 insertions, 0 deletions
diff --git a/drivers/soc/qcom/ice.c b/drivers/soc/qcom/ice.c
new file mode 100644
index 0000000000..fbab7fe5c6
--- /dev/null
+++ b/drivers/soc/qcom/ice.c
@@ -0,0 +1,368 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Qualcomm ICE (Inline Crypto Engine) support.
+ *
+ * Copyright (c) 2013-2019, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2019, Google LLC
+ * Copyright (c) 2023, Linaro Limited
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/iopoll.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#include <linux/firmware/qcom/qcom_scm.h>
+
+#include <soc/qcom/ice.h>
+
+#define AES_256_XTS_KEY_SIZE			64
+
+/* QCOM ICE registers */
+#define QCOM_ICE_REG_VERSION			0x0008
+#define QCOM_ICE_REG_FUSE_SETTING		0x0010
+#define QCOM_ICE_REG_BIST_STATUS		0x0070
+#define QCOM_ICE_REG_ADVANCED_CONTROL		0x1000
+
+/* BIST ("built-in self-test") status flags */
+#define QCOM_ICE_BIST_STATUS_MASK		GENMASK(31, 28)
+
+#define QCOM_ICE_FUSE_SETTING_MASK		0x1
+#define QCOM_ICE_FORCE_HW_KEY0_SETTING_MASK	0x2
+#define QCOM_ICE_FORCE_HW_KEY1_SETTING_MASK	0x4
+
+#define qcom_ice_writel(engine, val, reg)	\
+	writel((val), (engine)->base + (reg))
+
+#define qcom_ice_readl(engine, reg)	\
+	readl((engine)->base + (reg))
+
+struct qcom_ice {
+	struct device *dev;
+	void __iomem *base;
+	struct device_link *link;
+
+	struct clk *core_clk;
+};
+
+static bool qcom_ice_check_supported(struct qcom_ice *ice)
+{
+	u32 regval = qcom_ice_readl(ice, QCOM_ICE_REG_VERSION);
+	struct device *dev = ice->dev;
+	int major = FIELD_GET(GENMASK(31, 24), regval);
+	int minor = FIELD_GET(GENMASK(23, 16), regval);
+	int step = FIELD_GET(GENMASK(15, 0), regval);
+
+	/* For now this driver only supports ICE version 3 and 4. */
+	if (major != 3 && major != 4) {
+		dev_warn(dev, "Unsupported ICE version: v%d.%d.%d\n",
+			 major, minor, step);
+		return false;
+	}
+
+	dev_info(dev, "Found QC Inline Crypto Engine (ICE) v%d.%d.%d\n",
+		 major, minor, step);
+
+	/* If fuses are blown, ICE might not work in the standard way. */
+	regval = qcom_ice_readl(ice, QCOM_ICE_REG_FUSE_SETTING);
+	if (regval & (QCOM_ICE_FUSE_SETTING_MASK |
+		      QCOM_ICE_FORCE_HW_KEY0_SETTING_MASK |
+		      QCOM_ICE_FORCE_HW_KEY1_SETTING_MASK)) {
+		dev_warn(dev, "Fuses are blown; ICE is unusable!\n");
+		return false;
+	}
+
+	return true;
+}
+
+static void qcom_ice_low_power_mode_enable(struct qcom_ice *ice)
+{
+	u32 regval;
+
+	regval = qcom_ice_readl(ice, QCOM_ICE_REG_ADVANCED_CONTROL);
+
+	/* Enable low power mode sequence */
+	regval |= 0x7000;
+	qcom_ice_writel(ice, regval, QCOM_ICE_REG_ADVANCED_CONTROL);
+}
+
+static void qcom_ice_optimization_enable(struct qcom_ice *ice)
+{
+	u32 regval;
+
+	/* ICE Optimizations Enable Sequence */
+	regval = qcom_ice_readl(ice, QCOM_ICE_REG_ADVANCED_CONTROL);
+	regval |= 0xd807100;
+	/* ICE HPG requires delay before writing */
+	udelay(5);
+	qcom_ice_writel(ice, regval, QCOM_ICE_REG_ADVANCED_CONTROL);
+	udelay(5);
+}
+
+/*
+ * Wait until the ICE BIST (built-in self-test) has completed.
+ *
+ * This may be necessary before ICE can be used.
+ * Note that we don't really care whether the BIST passed or failed;
+ * we really just want to make sure that it isn't still running. This is
+ * because (a) the BIST is a FIPS compliance thing that never fails in
+ * practice, (b) ICE is documented to reject crypto requests if the BIST
+ * fails, so we needn't do it in software too, and (c) properly testing
+ * storage encryption requires testing the full storage stack anyway,
+ * and not relying on hardware-level self-tests.
+ */
+static int qcom_ice_wait_bist_status(struct qcom_ice *ice)
+{
+	u32 regval;
+	int err;
+
+	err = readl_poll_timeout(ice->base + QCOM_ICE_REG_BIST_STATUS,
+				 regval, !(regval & QCOM_ICE_BIST_STATUS_MASK),
+				 50, 5000);
+	if (err)
+		dev_err(ice->dev, "Timed out waiting for ICE self-test to complete\n");
+
+	return err;
+}
+
+int qcom_ice_enable(struct qcom_ice *ice)
+{
+	qcom_ice_low_power_mode_enable(ice);
+	qcom_ice_optimization_enable(ice);
+
+	return qcom_ice_wait_bist_status(ice);
+}
+EXPORT_SYMBOL_GPL(qcom_ice_enable);
+
+int qcom_ice_resume(struct qcom_ice *ice)
+{
+	struct device *dev = ice->dev;
+	int err;
+
+	err = clk_prepare_enable(ice->core_clk);
+	if (err) {
+		dev_err(dev, "failed to enable core clock (%d)\n",
+			err);
+		return err;
+	}
+
+	return qcom_ice_wait_bist_status(ice);
+}
+EXPORT_SYMBOL_GPL(qcom_ice_resume);
+
+int qcom_ice_suspend(struct qcom_ice *ice)
+{
+	clk_disable_unprepare(ice->core_clk);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(qcom_ice_suspend);
+
+int qcom_ice_program_key(struct qcom_ice *ice,
+			 u8 algorithm_id, u8 key_size,
+			 const u8 crypto_key[], u8 data_unit_size,
+			 int slot)
+{
+	struct device *dev = ice->dev;
+	union {
+		u8 bytes[AES_256_XTS_KEY_SIZE];
+		u32 words[AES_256_XTS_KEY_SIZE / sizeof(u32)];
+	} key;
+	int i;
+	int err;
+
+	/* Only AES-256-XTS has been tested so far. */
+	if (algorithm_id != QCOM_ICE_CRYPTO_ALG_AES_XTS ||
+	    key_size != QCOM_ICE_CRYPTO_KEY_SIZE_256) {
+		dev_err_ratelimited(dev,
+				    "Unhandled crypto capability; algorithm_id=%d, key_size=%d\n",
+				    algorithm_id, key_size);
+		return -EINVAL;
+	}
+
+	memcpy(key.bytes, crypto_key, AES_256_XTS_KEY_SIZE);
+
+	/* The SCM call requires that the key words are encoded in big endian */
+	for (i = 0; i < ARRAY_SIZE(key.words); i++)
+		__cpu_to_be32s(&key.words[i]);
+
+	err = qcom_scm_ice_set_key(slot, key.bytes, AES_256_XTS_KEY_SIZE,
+				   QCOM_SCM_ICE_CIPHER_AES_256_XTS,
+				   data_unit_size);
+
+	memzero_explicit(&key, sizeof(key));
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(qcom_ice_program_key);
+
+int qcom_ice_evict_key(struct qcom_ice *ice, int slot)
+{
+	return qcom_scm_ice_invalidate_key(slot);
+}
+EXPORT_SYMBOL_GPL(qcom_ice_evict_key);
+
+static struct qcom_ice *qcom_ice_create(struct device *dev,
+					void __iomem *base)
+{
+	struct qcom_ice *engine;
+
+	if (!qcom_scm_is_available())
+		return ERR_PTR(-EPROBE_DEFER);
+
+	if (!qcom_scm_ice_available()) {
+		dev_warn(dev, "ICE SCM interface not found\n");
+		return NULL;
+	}
+
+	engine = devm_kzalloc(dev, sizeof(*engine), GFP_KERNEL);
+	if (!engine)
+		return ERR_PTR(-ENOMEM);
+
+	engine->dev = dev;
+	engine->base = base;
+
+	/*
+	 * Legacy DT binding uses different clk names for each consumer,
+	 * so lets try those first. If none of those are a match, it means
+	 * the we only have one clock and it is part of the dedicated DT node.
+	 * Also, enable the clock before we check what HW version the driver
+	 * supports.
+	 */
+	engine->core_clk = devm_clk_get_optional_enabled(dev, "ice_core_clk");
+	if (!engine->core_clk)
+		engine->core_clk = devm_clk_get_optional_enabled(dev, "ice");
+	if (!engine->core_clk)
+		engine->core_clk = devm_clk_get_enabled(dev, NULL);
+	if (IS_ERR(engine->core_clk))
+		return ERR_CAST(engine->core_clk);
+
+	if (!qcom_ice_check_supported(engine))
+		return ERR_PTR(-EOPNOTSUPP);
+
+	dev_dbg(dev, "Registered Qualcomm Inline Crypto Engine\n");
+
+	return engine;
+}
+
+/**
+ * of_qcom_ice_get() - get an ICE instance from a DT node
+ * @dev: device pointer for the consumer device
+ *
+ * This function will provide an ICE instance either by creating one for the
+ * consumer device if its DT node provides the 'ice' reg range and the 'ice'
+ * clock (for legacy DT style). On the other hand, if consumer provides a
+ * phandle via 'qcom,ice' property to an ICE DT, the ICE instance will already
+ * be created and so this function will return that instead.
+ *
+ * Return: ICE pointer on success, NULL if there is no ICE data provided by the
+ * consumer or ERR_PTR() on error.
+ */
+struct qcom_ice *of_qcom_ice_get(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct qcom_ice *ice;
+	struct device_node *node;
+	struct resource *res;
+	void __iomem *base;
+
+	if (!dev || !dev->of_node)
+		return ERR_PTR(-ENODEV);
+
+	/*
+	 * In order to support legacy style devicetree bindings, we need
+	 * to create the ICE instance using the consumer device and the reg
+	 * range called 'ice' it provides.
+	 */
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ice");
+	if (res) {
+		base = devm_ioremap_resource(&pdev->dev, res);
+		if (IS_ERR(base))
+			return ERR_CAST(base);
+
+		/* create ICE instance using consumer dev */
+		return qcom_ice_create(&pdev->dev, base);
+	}
+
+	/*
+	 * If the consumer node does not provider an 'ice' reg range
+	 * (legacy DT binding), then it must at least provide a phandle
+	 * to the ICE devicetree node, otherwise ICE is not supported.
+	 */
+	node = of_parse_phandle(dev->of_node, "qcom,ice", 0);
+	if (!node)
+		return NULL;
+
+	pdev = of_find_device_by_node(node);
+	if (!pdev) {
+		dev_err(dev, "Cannot find device node %s\n", node->name);
+		ice = ERR_PTR(-EPROBE_DEFER);
+		goto out;
+	}
+
+	ice = platform_get_drvdata(pdev);
+	if (!ice) {
+		dev_err(dev, "Cannot get ice instance from %s\n",
+			dev_name(&pdev->dev));
+		platform_device_put(pdev);
+		ice = ERR_PTR(-EPROBE_DEFER);
+		goto out;
+	}
+
+	ice->link = device_link_add(dev, &pdev->dev, DL_FLAG_AUTOREMOVE_SUPPLIER);
+	if (!ice->link) {
+		dev_err(&pdev->dev,
+			"Failed to create device link to consumer %s\n",
+			dev_name(dev));
+		platform_device_put(pdev);
+		ice = ERR_PTR(-EINVAL);
+	}
+
+out:
+	of_node_put(node);
+
+	return ice;
+}
+EXPORT_SYMBOL_GPL(of_qcom_ice_get);
+
+static int qcom_ice_probe(struct platform_device *pdev)
+{
+	struct qcom_ice *engine;
+	void __iomem *base;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base)) {
+		dev_warn(&pdev->dev, "ICE registers not found\n");
+		return PTR_ERR(base);
+	}
+
+	engine = qcom_ice_create(&pdev->dev, base);
+	if (IS_ERR(engine))
+		return PTR_ERR(engine);
+
+	platform_set_drvdata(pdev, engine);
+
+	return 0;
+}
+
+static const struct of_device_id qcom_ice_of_match_table[] = {
+	{ .compatible = "qcom,inline-crypto-engine" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, qcom_ice_of_match_table);
+
+static struct platform_driver qcom_ice_driver = {
+	.probe	= qcom_ice_probe,
+	.driver = {
+		.name = "qcom-ice",
+		.of_match_table = qcom_ice_of_match_table,
+	},
+};
+
+module_platform_driver(qcom_ice_driver);
+
+MODULE_DESCRIPTION("Qualcomm Inline Crypto Engine driver");
+MODULE_LICENSE("GPL");