// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright 2019 Google LLC
 */

#include <ufs/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);

        /* 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_crypto_profile *profile,
                                         const struct blk_crypto_key *key,
                                         unsigned int slot)
{
        struct ufs_hba *hba = ufs_hba_from_crypto_profile(profile);
        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 = {};

        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->bytes, key->size/2);
                memcpy(cfg.crypto_key + UFS_CRYPTO_KEY_MAX_SIZE/2,
                       key->bytes + key->size/2, key->size/2);
        } else {
                memcpy(cfg.crypto_key, key->bytes, key->size);
        }

        ufshcd_program_key(hba, &cfg, slot);

        memzero_explicit(&cfg, sizeof(cfg));
        return 0;
}

static int ufshcd_crypto_keyslot_evict(struct blk_crypto_profile *profile,
                                       const struct blk_crypto_key *key,
                                       unsigned int slot)
{
        struct ufs_hba *hba = ufs_hba_from_crypto_profile(profile);
        /*
         * 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 = {};

        ufshcd_program_key(hba, &cfg, slot);
        return 0;
}

/*
 * Reprogram the keyslots if needed, and return true if CRYPTO_GENERAL_ENABLE
 * should be used in the host controller initialization sequence.
 */
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_crypto_reprogram_all_keys(&hba->crypto_profile);

        if (hba->quirks & UFSHCD_QUIRK_BROKEN_CRYPTO_ENABLE)
                return false;

        return true;
}

static const struct blk_crypto_ll_ops ufshcd_crypto_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;

        if (hba->quirks & UFSHCD_QUIRK_CUSTOM_CRYPTO_PROFILE)
                return 0;

        /*
         * 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_crypto_profile_init(
                        hba->dev, &hba->crypto_profile,
                        hba->crypto_capabilities.config_count + 1);
        if (err)
                goto out;

        hba->crypto_profile.ll_ops = ufshcd_crypto_ops;
        /* UFS only supports 8 bytes for any DUN */
        hba->crypto_profile.max_dun_bytes_supported = 8;
        hba->crypto_profile.key_types_supported = BLK_CRYPTO_KEY_TYPE_RAW;
        hba->crypto_profile.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->crypto_profile.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. */
        for (slot = 0; slot < hba->crypto_profile.num_slots; slot++)
                hba->crypto_profile.ll_ops.keyslot_evict(&hba->crypto_profile,
                                                         NULL, slot);
}

void ufshcd_crypto_register(struct ufs_hba *hba, struct request_queue *q)
{
        if (hba->caps & UFSHCD_CAP_CRYPTO)
                blk_crypto_register(&hba->crypto_profile, q);
}