diff options
Diffstat (limited to 'drivers/scsi/ufs/ufshcd-crypto.c')
| -rw-r--r-- | drivers/scsi/ufs/ufshcd-crypto.c | 245 |
1 files changed, 245 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..d2edbd960ebf --- /dev/null +++ b/drivers/scsi/ufs/ufshcd-crypto.c @@ -0,0 +1,245 @@ +// 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 = { 0 }; + 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 = { 0 }; + + 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 = 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); +} |