drivers/scsi/ufs/ufshcd-crypto.c - linux - Git at Google

 // 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 int 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);
 	int err = 0;

 	ufshcd_hold(hba, false);

 	if (hba->vops && hba->vops->program_key) {
 		err = hba->vops->program_key(hba, cfg, slot);
 		goto out;
 	}

 	/* 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]));
 out:
 	ufshcd_release(hba);
 	return err;
 }

 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 = {};
 	int err;

 	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);
 	}

 	err = ufshcd_program_key(hba, &cfg, slot);

 	memzero_explicit(&cfg, sizeof(cfg));
 	return err;
 }

 static int 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 = {};

 	return 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);

 	return ufshcd_clear_keyslot(hba, slot);
 }

 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 = devm_blk_ksm_init(hba->dev, &hba->ksm,
 				hba->crypto_capabilities.config_count + 1);
 	if (err)
 		goto out;

 	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:
 	/* 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);
 }
	// 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 int 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);
	int err = 0;

	ufshcd_hold(hba, false);

	if (hba->vops && hba->vops->program_key) {
	err = hba->vops->program_key(hba, cfg, slot);
	goto out;
	}

	/* 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]));
	out:
	ufshcd_release(hba);
	return err;
	}

	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 = {};
	int err;

	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);
	}

	err = ufshcd_program_key(hba, &cfg, slot);

	memzero_explicit(&cfg, sizeof(cfg));
	return err;
	}

	static int 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 = {};

	return 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);

	return ufshcd_clear_keyslot(hba, slot);
	}

	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 = devm_blk_ksm_init(hba->dev, &hba->ksm,
	hba->crypto_capabilities.config_count + 1);
	if (err)
	goto out;

	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:
	/* 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);
	}