[RFC PATCH 5/5] scsi: ufs-qcom: add Inline Crypto Engine support

[Eric Biggers <ebiggers@kernel.org>]

From: Eric Biggers <ebiggers@google.com>

Add support for Qualcomm Inline Crypto Engine (ICE) to ufs-qcom.

The standards-compliant parts, such as querying the crypto capabilities
and enabling crypto for individual UFS requests, are already handled by
ufshcd-crypto.c, which itself is wired into the blk-crypto framework.
However, ICE requires vendor-specific init, enable, and resume logic,
and it requires that keys be programmed and evicted by vendor-specific
SMC calls.  Make the ufs-qcom driver handle these details.

I tested this on Dragonboard 845c, which is a publicly available
development board that uses the Snapdragon 845 SoC.  This is the same
SoC used in the Pixel 3 and Pixel 3 XL phones.  This testing included
(among other things) verifying that the expected ciphertext was produced
for the key and IV used, both manually using ext4 encryption and
automatically using a block layer self-test I've written.

This is based very loosely on the vendor-provided driver in the kernel
source code for the Pixel 3, but I've greatly simplified it.  Also, for
now I've only included support for major version 3 of ICE, since that's
all I have the hardware to test with the mainline kernel.  Plus it
appears that version 3 is easier to use than older versions of ICE.

For now, only allow using AES-256-XTS.  The hardware also declares
support for AES-128-XTS, AES-{128,256}-ECB, and AES-{128,256}-CBC
(BitLocker variant).  But none of these others are really useful, and
they'd need to be individually tested to be sure they worked properly.

This commit also changes the name of the loadable module from "ufs-qcom"
to "ufs_qcom", as this is necessary to compile it from multiple source
files (unless we were to rename ufs-qcom.c).

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 MAINTAINERS                     |   2 +-
 drivers/scsi/ufs/Kconfig        |   1 +
 drivers/scsi/ufs/Makefile       |   4 +-
 drivers/scsi/ufs/ufs-qcom-ice.c | 248 ++++++++++++++++++++++++++++++++
 drivers/scsi/ufs/ufs-qcom.c     |  14 +-
 drivers/scsi/ufs/ufs-qcom.h     |  35 +++++
 6 files changed, 301 insertions(+), 3 deletions(-)
 create mode 100644 drivers/scsi/ufs/ufs-qcom-ice.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 8982c6e013b3c..da304fcc78d3e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2169,7 +2169,7 @@ F:	drivers/pci/controller/dwc/pcie-qcom.c
 F:	drivers/phy/qualcomm/
 F:	drivers/power/*/msm*
 F:	drivers/reset/reset-qcom-*
-F:	drivers/scsi/ufs/ufs-qcom.*
+F:	drivers/scsi/ufs/ufs-qcom*
 F:	drivers/spi/spi-qup.c
 F:	drivers/spi/spi-geni-qcom.c
 F:	drivers/spi/spi-qcom-qspi.c
diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
index c69f1b49167b0..7d1260988ab2b 100644
--- a/drivers/scsi/ufs/Kconfig
+++ b/drivers/scsi/ufs/Kconfig
@@ -99,6 +99,7 @@ config SCSI_UFS_DWC_TC_PLATFORM
 config SCSI_UFS_QCOM
 	tristate "QCOM specific hooks to UFS controller platform driver"
 	depends on SCSI_UFSHCD_PLATFORM && ARCH_QCOM
+	select QCOM_SCM
 	select RESET_CONTROLLER
 	help
 	  This selects the QCOM specific additions to UFSHCD platform driver.
diff --git a/drivers/scsi/ufs/Makefile b/drivers/scsi/ufs/Makefile
index e88cdcde83fde..151c41279c783 100644
--- a/drivers/scsi/ufs/Makefile
+++ b/drivers/scsi/ufs/Makefile
@@ -3,7 +3,9 @@
 obj-$(CONFIG_SCSI_UFS_DWC_TC_PCI) += tc-dwc-g210-pci.o ufshcd-dwc.o tc-dwc-g210.o
 obj-$(CONFIG_SCSI_UFS_DWC_TC_PLATFORM) += tc-dwc-g210-pltfrm.o ufshcd-dwc.o tc-dwc-g210.o
 obj-$(CONFIG_SCSI_UFS_CDNS_PLATFORM) += cdns-pltfrm.o
-obj-$(CONFIG_SCSI_UFS_QCOM) += ufs-qcom.o
+obj-$(CONFIG_SCSI_UFS_QCOM) += ufs_qcom.o
+ufs_qcom-y += ufs-qcom.o
+ufs_qcom-$(CONFIG_SCSI_UFS_CRYPTO) += ufs-qcom-ice.o
 obj-$(CONFIG_SCSI_UFSHCD) += ufshcd-core.o
 ufshcd-core-y				+= ufshcd.o ufs-sysfs.o
 ufshcd-core-$(CONFIG_SCSI_UFS_BSG)	+= ufs_bsg.o
diff --git a/drivers/scsi/ufs/ufs-qcom-ice.c b/drivers/scsi/ufs/ufs-qcom-ice.c
new file mode 100644
index 0000000000000..151e995ca5035
--- /dev/null
+++ b/drivers/scsi/ufs/ufs-qcom-ice.c
@@ -0,0 +1,248 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Qualcomm ICE (Inline Cryptographic Engine) support.
+ *
+ * Copyright (c) 2014-2019, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2019 Google LLC
+ */
+
+#include <linux/platform_device.h>
+#include <linux/qcom_scm.h>
+
+#include "ufshcd-crypto.h"
+#include "ufs-qcom.h"
+
+#define AES_256_XTS_KEY_SIZE			64
+
+/* QCOM ICE registers */
+
+#define QCOM_ICE_REGS_CONTROL			0x0000
+#define QCOM_ICE_REGS_RESET			0x0004
+#define QCOM_ICE_REGS_VERSION			0x0008
+#define QCOM_ICE_REGS_FUSE_SETTING		0x0010
+#define QCOM_ICE_REGS_PARAMETERS_1		0x0014
+#define QCOM_ICE_REGS_PARAMETERS_2		0x0018
+#define QCOM_ICE_REGS_PARAMETERS_3		0x001C
+#define QCOM_ICE_REGS_PARAMETERS_4		0x0020
+#define QCOM_ICE_REGS_PARAMETERS_5		0x0024
+
+/* QCOM ICE v3.X only */
+#define QCOM_ICE_GENERAL_ERR_STTS		0x0040
+#define QCOM_ICE_INVALID_CCFG_ERR_STTS		0x0030
+#define QCOM_ICE_GENERAL_ERR_MASK		0x0044
+
+/* QCOM ICE v2.X only */
+#define QCOM_ICE_REGS_NON_SEC_IRQ_STTS		0x0040
+#define QCOM_ICE_REGS_NON_SEC_IRQ_MASK		0x0044
+
+#define QCOM_ICE_REGS_NON_SEC_IRQ_CLR		0x0048
+#define QCOM_ICE_REGS_STREAM1_ERROR_SYNDROME1	0x0050
+#define QCOM_ICE_REGS_STREAM1_ERROR_SYNDROME2	0x0054
+#define QCOM_ICE_REGS_STREAM2_ERROR_SYNDROME1	0x0058
+#define QCOM_ICE_REGS_STREAM2_ERROR_SYNDROME2	0x005C
+#define QCOM_ICE_REGS_STREAM1_BIST_ERROR_VEC	0x0060
+#define QCOM_ICE_REGS_STREAM2_BIST_ERROR_VEC	0x0064
+#define QCOM_ICE_REGS_STREAM1_BIST_FINISH_VEC	0x0068
+#define QCOM_ICE_REGS_STREAM2_BIST_FINISH_VEC	0x006C
+#define QCOM_ICE_REGS_BIST_STATUS		0x0070
+#define QCOM_ICE_REGS_BYPASS_STATUS		0x0074
+#define QCOM_ICE_REGS_ADVANCED_CONTROL		0x1000
+#define QCOM_ICE_REGS_ENDIAN_SWAP		0x1004
+#define QCOM_ICE_REGS_TEST_BUS_CONTROL		0x1010
+#define QCOM_ICE_REGS_TEST_BUS_REG		0x1014
+
+/* BIST ("built-in self-test"?) status flags */
+#define ICE_BIST_STATUS_MASK			0xF0000000
+
+#define ICE_FUSE_SETTING_MASK			0x1
+#define ICE_FORCE_HW_KEY0_SETTING_MASK		0x2
+#define ICE_FORCE_HW_KEY1_SETTING_MASK		0x4
+
+#define qcom_ice_writel(host, val, reg)	\
+	writel((val), (host)->ice_mmio + (reg))
+#define qcom_ice_readl(host, reg)	\
+	readl((host)->ice_mmio + (reg))
+
+static int qcom_ice_check_version(struct ufs_qcom_host *host)
+{
+	u32 regval = qcom_ice_readl(host, QCOM_ICE_REGS_VERSION);
+	int major = regval >> 24;
+	int minor = (regval >> 16) & 0xFF;
+	int step = regval & 0xFFFF;
+
+	/* For now this driver only supports ICE version 3. */
+	if (major != 3) {
+		dev_warn(host->hba->dev,
+			 "Unsupported ICE device (%d.%d.%d) @0x%pK\n",
+			 major, minor, step, host->ice_mmio);
+		return -ENODEV;
+	}
+
+	dev_info(host->hba->dev, "QC ICE %d.%d.%d device found @0x%pK\n",
+		 major, minor, step, host->ice_mmio);
+
+	host->ice_ver.major = major;
+	host->ice_ver.minor = minor;
+	host->ice_ver.step = step;
+	return 0;
+}
+
+static int qcom_ice_check_fuses(struct ufs_qcom_host *host)
+{
+	u32 regval = qcom_ice_readl(host, QCOM_ICE_REGS_FUSE_SETTING);
+
+	if (regval & (ICE_FUSE_SETTING_MASK |
+		      ICE_FORCE_HW_KEY0_SETTING_MASK |
+		      ICE_FORCE_HW_KEY1_SETTING_MASK)) {
+		dev_err(host->hba->dev, "Fuses are blown; ICE is unusable!\n");
+		return -ENODEV;
+	}
+	return 0;
+}
+
+int ufs_qcom_ice_init(struct ufs_qcom_host *host)
+{
+	struct device *dev = host->hba->dev;
+	struct platform_device *pdev = to_platform_device(dev);
+	struct resource *res;
+	int err;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
+	if (!res)
+		return -ENODEV;
+
+	if (!qcom_scm_ice_available()) {
+		dev_warn(host->hba->dev,
+			 "ICE device is available, but SCM interface isn't.\n");
+		return -ENODEV;
+	}
+
+	host->ice_mmio = devm_ioremap_resource(dev, res);
+	if (IS_ERR(host->ice_mmio)) {
+		err = PTR_ERR(host->ice_mmio);
+		dev_err(dev, "failed to map ICE mmio registers, err %d\n", err);
+		return err;
+	}
+
+	err = qcom_ice_check_version(host);
+	if (err)
+		return err;
+
+	return qcom_ice_check_fuses(host);
+}
+
+static void qcom_ice_low_power_mode_enable(struct ufs_qcom_host *host)
+{
+	u32 regval;
+
+	regval = qcom_ice_readl(host, QCOM_ICE_REGS_ADVANCED_CONTROL);
+	/*
+	 * Enable low power mode sequence
+	 * [0]-0, [1]-0, [2]-0, [3]-E, [4]-0, [5]-0, [6]-0, [7]-0
+	 */
+	regval |= 0x7000;
+	qcom_ice_writel(host, regval, QCOM_ICE_REGS_ADVANCED_CONTROL);
+}
+
+static void qcom_ice_optimization_enable(struct ufs_qcom_host *host)
+{
+	u32 regval;
+
+	/* ICE Optimizations Enable Sequence */
+	regval = qcom_ice_readl(host, QCOM_ICE_REGS_ADVANCED_CONTROL);
+	regval |= 0xD807100;
+	/* ICE HPG requires delay before writing */
+	udelay(5);
+	qcom_ice_writel(host, regval, QCOM_ICE_REGS_ADVANCED_CONTROL);
+	udelay(5);
+}
+
+int ufs_qcom_ice_enable(struct ufs_qcom_host *host)
+{
+	if (!ufshcd_is_crypto_enabled(host->hba))
+		return 0;
+	qcom_ice_low_power_mode_enable(host);
+	qcom_ice_optimization_enable(host);
+	return ufs_qcom_ice_resume(host);
+}
+
+/* Poll until all BIST bits are reset */
+static int qcom_ice_wait_bist_status(struct ufs_qcom_host *host)
+{
+	int count;
+	u32 reg;
+
+	for (count = 0; count < 100; count++) {
+		reg = qcom_ice_readl(host, QCOM_ICE_REGS_BIST_STATUS);
+		if (!(reg & ICE_BIST_STATUS_MASK))
+			break;
+		udelay(50);
+	}
+	if (reg)
+		return -ETIMEDOUT;
+	return 0;
+}
+
+int ufs_qcom_ice_resume(struct ufs_qcom_host *host)
+{
+	int err;
+
+	if (!ufshcd_is_crypto_enabled(host->hba))
+		return 0;
+
+	err = qcom_ice_wait_bist_status(host);
+	if (err) {
+		dev_err(host->hba->dev, "BIST status error (%d)\n", err);
+		return err;
+	}
+	return 0;
+}
+
+/*
+ * Program a key into a QC ICE keyslot, or evict a keyslot.  QC ICE requires
+ * vendor-specific SCM calls for this; it doesn't support the standard way.
+ */
+int ufs_qcom_ice_program_key(struct ufs_hba *hba,
+			     const union ufs_crypto_cfg_entry *cfg, int slot)
+{
+	union ufs_crypto_cap_entry cap;
+	enum qcom_scm_ice_cipher_mode mode;
+	union {
+		u8 bytes[UFS_CRYPTO_KEY_MAX_SIZE];
+		u32 words[UFS_CRYPTO_KEY_MAX_SIZE / sizeof(u32)];
+	} key;
+	int key_size;
+	int i;
+	int err;
+
+	if (!(cfg->config_enable & UFS_CRYPTO_CONFIGURATION_ENABLE))
+		return qcom_scm_ice_invalidate_key(slot);
+
+	/* Only AES-256-XTS has been tested so far. */
+	cap = hba->crypto_cap_array[cfg->crypto_cap_idx];
+	if (cap.algorithm_id == UFS_CRYPTO_ALG_AES_XTS &&
+	    cap.key_size == UFS_CRYPTO_KEY_SIZE_256) {
+		mode = QCOM_SCM_ICE_CIPHER_MODE_XTS_256;
+		key_size = AES_256_XTS_KEY_SIZE;
+		memcpy(key.bytes, cfg->crypto_key, key_size);
+	} else {
+		dev_err_ratelimited(hba->dev,
+				    "Unhandled crypto capability; algorithm_id=%d, key_size=%d\n",
+				    cap.algorithm_id, cap.key_size);
+		err = -ENOTSUPP;
+		goto out;
+	}
+
+	/*
+	 * ICE (or maybe the SCM call?) byte-swaps the 32-bit words of the key.
+	 * So we have to do the same, in order for the final key be correct.
+	 */
+	for (i = 0; i < key_size / sizeof(u32); i++)
+		__cpu_to_be32s(&key.words[i]);
+
+	err = qcom_scm_ice_set_key(slot, key.bytes, key_size, mode,
+				   cfg->data_unit_size);
+out:
+	memzero_explicit(&key, sizeof(key));
+	return err;
+}
diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index c69c29a1ceb90..94e5203699976 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -365,7 +365,7 @@ static int ufs_qcom_hce_enable_notify(struct ufs_hba *hba,
 		/* check if UFS PHY moved from DISABLED to HIBERN8 */
 		err = ufs_qcom_check_hibern8(hba);
 		ufs_qcom_enable_hw_clk_gating(hba);
-
+		ufs_qcom_ice_enable(host);
 		break;
 	default:
 		dev_err(hba->dev, "%s: invalid status %d\n", __func__, status);
@@ -616,6 +616,10 @@ static int ufs_qcom_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 			return err;
 	}
 
+	err = ufs_qcom_ice_resume(host);
+	if (err)
+		return err;
+
 	hba->is_sys_suspended = false;
 	return 0;
 }
@@ -1238,6 +1242,13 @@ static int ufs_qcom_init(struct ufs_hba *hba)
 	ufs_qcom_set_caps(hba);
 	ufs_qcom_advertise_quirks(hba);
 
+	err = ufs_qcom_ice_init(host);
+	if (err) {
+		if (err != -ENODEV)
+			goto out_variant_clear;
+		hba->quirks |= UFSHCD_QUIRK_BROKEN_CRYPTO;
+	}
+
 	ufs_qcom_setup_clocks(hba, true, POST_CHANGE);
 
 	if (hba->dev->id < MAX_UFS_QCOM_HOSTS)
@@ -1651,6 +1662,7 @@ static const struct ufs_hba_variant_ops ufs_hba_qcom_vops = {
 	.resume			= ufs_qcom_resume,
 	.dbg_register_dump	= ufs_qcom_dump_dbg_regs,
 	.device_reset		= ufs_qcom_device_reset,
+	.program_key		= ufs_qcom_ice_program_key,
 };
 
 /**
diff --git a/drivers/scsi/ufs/ufs-qcom.h b/drivers/scsi/ufs/ufs-qcom.h
index 2d95e7cc71874..953c0c806fb94 100644
--- a/drivers/scsi/ufs/ufs-qcom.h
+++ b/drivers/scsi/ufs/ufs-qcom.h
@@ -191,6 +191,13 @@ struct ufs_hw_version {
 	u8 major;
 };
 
+/* Inline Crypto Engine hardware version: major.minor.step */
+struct ufs_qcom_ice_hw_version {
+	u16 step;
+	u8 minor;
+	u8 major;
+};
+
 struct ufs_qcom_testbus {
 	u8 select_major;
 	u8 select_minor;
@@ -227,6 +234,10 @@ struct ufs_qcom_host {
 	void __iomem *dev_ref_clk_ctrl_mmio;
 	bool is_dev_ref_clk_enabled;
 	struct ufs_hw_version hw_ver;
+#ifdef CONFIG_SCSI_UFS_CRYPTO
+	void __iomem *ice_mmio;
+	struct ufs_qcom_ice_hw_version ice_ver;
+#endif
 
 	u32 dev_ref_clk_en_mask;
 
@@ -264,4 +275,28 @@ static inline bool ufs_qcom_cap_qunipro(struct ufs_qcom_host *host)
 		return false;
 }
 
+/* ufs-qcom-ice.c */
+
+#ifdef CONFIG_SCSI_UFS_CRYPTO
+int ufs_qcom_ice_init(struct ufs_qcom_host *host);
+int ufs_qcom_ice_enable(struct ufs_qcom_host *host);
+int ufs_qcom_ice_resume(struct ufs_qcom_host *host);
+int ufs_qcom_ice_program_key(struct ufs_hba *hba,
+			     const union ufs_crypto_cfg_entry *cfg, int slot);
+#else
+static inline int ufs_qcom_ice_init(struct ufs_qcom_host *host)
+{
+	return 0;
+}
+static inline int ufs_qcom_ice_enable(struct ufs_qcom_host *host)
+{
+	return 0;
+}
+static inline int ufs_qcom_ice_resume(struct ufs_qcom_host *host)
+{
+	return 0;
+}
+#define ufs_qcom_ice_program_key NULL
+#endif /* !CONFIG_SCSI_UFS_CRYPTO */
+
 #endif /* UFS_QCOM_H_ */
-- 
2.24.1