1 files changed, 238 insertions, 0 deletions
diff --git a/drivers/scsi/ufs/ufshcd-crypto.c b/drivers/scsi/ufs/ufshcd-crypto.c
new file mode 100644
index 000000000000..98ff87c38aa7
--- /dev/null
+++ b/drivers/scsi/ufs/ufshcd-crypto.c
@@ -0,0 +1,238 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 Google LLC
+ */
+
+#include "ufshcd.h"
+#include "ufshcd-crypto.h"
+
+/* Blk-crypto modes supported by UFS crypto */
+static const struct ufs_crypto_alg_entry {
+	enum ufs_crypto_alg ufs_alg;
+	enum ufs_crypto_key_size ufs_key_size;
+} ufs_crypto_algs[BLK_ENCRYPTION_MODE_MAX] = {
+	[BLK_ENCRYPTION_MODE_AES_256_XTS] = {
+		.ufs_alg = UFS_CRYPTO_ALG_AES_XTS,
+		.ufs_key_size = UFS_CRYPTO_KEY_SIZE_256,
+	},
+};
+
+static void ufshcd_program_key(struct ufs_hba *hba,
+			       const union ufs_crypto_cfg_entry *cfg,
+			       int slot)
+{
+	int i;
+	u32 slot_offset = hba->crypto_cfg_register + slot * sizeof(*cfg);
+
+	ufshcd_hold(hba, false);
+	/* Ensure that CFGE is cleared before programming the key */
+	ufshcd_writel(hba, 0, slot_offset + 16 * sizeof(cfg->reg_val[0]));
+	for (i = 0; i < 16; i++) {
+		ufshcd_writel(hba, le32_to_cpu(cfg->reg_val[i]),
+			      slot_offset + i * sizeof(cfg->reg_val[0]));
+	}
+	/* Write dword 17 */
+	ufshcd_writel(hba, le32_to_cpu(cfg->reg_val[17]),
+		      slot_offset + 17 * sizeof(cfg->reg_val[0]));
+	/* Dword 16 must be written last */
+	ufshcd_writel(hba, le32_to_cpu(cfg->reg_val[16]),
+		      slot_offset + 16 * sizeof(cfg->reg_val[0]));
+	ufshcd_release(hba);
+}
+
+static int ufshcd_crypto_keyslot_program(struct blk_keyslot_manager *ksm,
+					 const struct blk_crypto_key *key,
+					 unsigned int slot)
+{
+	struct ufs_hba *hba = container_of(ksm, struct ufs_hba, ksm);
+	const union ufs_crypto_cap_entry *ccap_array = hba->crypto_cap_array;
+	const struct ufs_crypto_alg_entry *alg =
+			&ufs_crypto_algs[key->crypto_cfg.crypto_mode];
+	u8 data_unit_mask = key->crypto_cfg.data_unit_size / 512;
+	int i;
+	int cap_idx = -1;
+	union ufs_crypto_cfg_entry cfg = { 0 };
+
+	BUILD_BUG_ON(UFS_CRYPTO_KEY_SIZE_INVALID != 0);
+	for (i = 0; i < hba->crypto_capabilities.num_crypto_cap; i++) {
+		if (ccap_array[i].algorithm_id == alg->ufs_alg &&
+		    ccap_array[i].key_size == alg->ufs_key_size &&
+		    (ccap_array[i].sdus_mask & data_unit_mask)) {
+			cap_idx = i;
+			break;
+		}
+	}
+
+	if (WARN_ON(cap_idx < 0))
+		return -EOPNOTSUPP;
+
+	cfg.data_unit_size = data_unit_mask;
+	cfg.crypto_cap_idx = cap_idx;
+	cfg.config_enable = UFS_CRYPTO_CONFIGURATION_ENABLE;
+
+	if (ccap_array[cap_idx].algorithm_id == UFS_CRYPTO_ALG_AES_XTS) {
+		/* In XTS mode, the blk_crypto_key's size is already doubled */
+		memcpy(cfg.crypto_key, key->raw, key->size/2);
+		memcpy(cfg.crypto_key + UFS_CRYPTO_KEY_MAX_SIZE/2,
+		       key->raw + key->size/2, key->size/2);
+	} else {
+		memcpy(cfg.crypto_key, key->raw, key->size);
+	}
+
+	ufshcd_program_key(hba, &cfg, slot);
+
+	memzero_explicit(&cfg, sizeof(cfg));
+	return 0;
+}
+
+static void ufshcd_clear_keyslot(struct ufs_hba *hba, int slot)
+{
+	/*
+	 * Clear the crypto cfg on the device. Clearing CFGE
+	 * might not be sufficient, so just clear the entire cfg.
+	 */
+	union ufs_crypto_cfg_entry cfg = { 0 };
+
+	ufshcd_program_key(hba, &cfg, slot);
+}
+
+static int ufshcd_crypto_keyslot_evict(struct blk_keyslot_manager *ksm,
+				       const struct blk_crypto_key *key,
+				       unsigned int slot)
+{
+	struct ufs_hba *hba = container_of(ksm, struct ufs_hba, ksm);
+
+	ufshcd_clear_keyslot(hba, slot);
+
+	return 0;
+}
+
+bool ufshcd_crypto_enable(struct ufs_hba *hba)
+{
+	if (!(hba->caps & UFSHCD_CAP_CRYPTO))
+		return false;
+
+	/* Reset might clear all keys, so reprogram all the keys. */
+	blk_ksm_reprogram_all_keys(&hba->ksm);
+	return true;
+}
+
+static const struct blk_ksm_ll_ops ufshcd_ksm_ops = {
+	.keyslot_program	= ufshcd_crypto_keyslot_program,
+	.keyslot_evict		= ufshcd_crypto_keyslot_evict,
+};
+
+static enum blk_crypto_mode_num
+ufshcd_find_blk_crypto_mode(union ufs_crypto_cap_entry cap)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ufs_crypto_algs); i++) {
+		BUILD_BUG_ON(UFS_CRYPTO_KEY_SIZE_INVALID != 0);
+		if (ufs_crypto_algs[i].ufs_alg == cap.algorithm_id &&
+		    ufs_crypto_algs[i].ufs_key_size == cap.key_size) {
+			return i;
+		}
+	}
+	return BLK_ENCRYPTION_MODE_INVALID;
+}
+
+/**
+ * ufshcd_hba_init_crypto_capabilities - Read crypto capabilities, init crypto
+ *					 fields in hba
+ * @hba: Per adapter instance
+ *
+ * Return: 0 if crypto was initialized or is not supported, else a -errno value.
+ */
+int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
+{
+	int cap_idx;
+	int err = 0;
+	enum blk_crypto_mode_num blk_mode_num;
+
+	/*
+	 * Don't use crypto if either the hardware doesn't advertise the
+	 * standard crypto capability bit *or* if the vendor specific driver
+	 * hasn't advertised that crypto is supported.
+	 */
+	if (!(hba->capabilities & MASK_CRYPTO_SUPPORT) ||
+	    !(hba->caps & UFSHCD_CAP_CRYPTO))
+		goto out;
+
+	hba->crypto_capabilities.reg_val =
+			cpu_to_le32(ufshcd_readl(hba, REG_UFS_CCAP));
+	hba->crypto_cfg_register =
+		(u32)hba->crypto_capabilities.config_array_ptr * 0x100;
+	hba->crypto_cap_array =
+		devm_kcalloc(hba->dev, hba->crypto_capabilities.num_crypto_cap,
+			     sizeof(hba->crypto_cap_array[0]), GFP_KERNEL);
+	if (!hba->crypto_cap_array) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	/* The actual number of configurations supported is (CFGC+1) */
+	err = blk_ksm_init(&hba->ksm,
+			   hba->crypto_capabilities.config_count + 1);
+	if (err)
+		goto out_free_caps;
+
+	hba->ksm.ksm_ll_ops = ufshcd_ksm_ops;
+	/* UFS only supports 8 bytes for any DUN */
+	hba->ksm.max_dun_bytes_supported = 8;
+	hba->ksm.dev = hba->dev;
+
+	/*
+	 * Cache all the UFS crypto capabilities and advertise the supported
+	 * crypto modes and data unit sizes to the block layer.
+	 */
+	for (cap_idx = 0; cap_idx < hba->crypto_capabilities.num_crypto_cap;
+	     cap_idx++) {
+		hba->crypto_cap_array[cap_idx].reg_val =
+			cpu_to_le32(ufshcd_readl(hba,
+						 REG_UFS_CRYPTOCAP +
+						 cap_idx * sizeof(__le32)));
+		blk_mode_num = ufshcd_find_blk_crypto_mode(
+						hba->crypto_cap_array[cap_idx]);
+		if (blk_mode_num != BLK_ENCRYPTION_MODE_INVALID)
+			hba->ksm.crypto_modes_supported[blk_mode_num] |=
+				hba->crypto_cap_array[cap_idx].sdus_mask * 512;
+	}
+
+	return 0;
+
+out_free_caps:
+	devm_kfree(hba->dev, hba->crypto_cap_array);
+out:
+	/* Indicate that init failed by clearing UFSHCD_CAP_CRYPTO */
+	hba->caps &= ~UFSHCD_CAP_CRYPTO;
+	return err;
+}
+
+/**
+ * ufshcd_init_crypto - Initialize crypto hardware
+ * @hba: Per adapter instance
+ */
+void ufshcd_init_crypto(struct ufs_hba *hba)
+{
+	int slot;
+
+	if (!(hba->caps & UFSHCD_CAP_CRYPTO))
+		return;
+
+	/* Clear all keyslots - the number of keyslots is (CFGC + 1) */
+	for (slot = 0; slot < hba->crypto_capabilities.config_count + 1; slot++)
+		ufshcd_clear_keyslot(hba, slot);
+}
+
+void ufshcd_crypto_setup_rq_keyslot_manager(struct ufs_hba *hba,
+					    struct request_queue *q)
+{
+	if (hba->caps & UFSHCD_CAP_CRYPTO)
+		blk_ksm_register(&hba->ksm, q);
+}
+
+void ufshcd_crypto_destroy_keyslot_manager(struct ufs_hba *hba)
+{
+	blk_ksm_destroy(&hba->ksm);
+}