linux/drivers/mmc/host/cqhci-crypto.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * CQHCI crypto engine (inline encryption) support
 *
 * Copyright 2020 Google LLC
 */

#include <linux/blk-crypto.h>
#include <linux/blk-crypto-profile.h>
#include <linux/mmc/host.h>

#include "cqhci-crypto.h"

/* Map from blk-crypto modes to CQHCI crypto algorithm IDs and key sizes */
static const struct cqhci_crypto_alg_entry { … } cqhci_crypto_algs[BLK_ENCRYPTION_MODE_MAX] = …;

static inline struct cqhci_host *
cqhci_host_from_crypto_profile(struct blk_crypto_profile *profile)
{ … }

static int cqhci_crypto_program_key(struct cqhci_host *cq_host,
				    const union cqhci_crypto_cfg_entry *cfg,
				    int slot)
{ … }

static int cqhci_crypto_keyslot_program(struct blk_crypto_profile *profile,
					const struct blk_crypto_key *key,
					unsigned int slot)

{ … }

static int cqhci_crypto_clear_keyslot(struct cqhci_host *cq_host, int slot)
{ … }

static int cqhci_crypto_keyslot_evict(struct blk_crypto_profile *profile,
				      const struct blk_crypto_key *key,
				      unsigned int slot)
{ … }

/*
 * The keyslot management operations for CQHCI crypto.
 *
 * Note that the block layer ensures that these are never called while the host
 * controller is runtime-suspended.  However, the CQE won't necessarily be
 * "enabled" when these are called, i.e. CQHCI_ENABLE might not be set in the
 * CQHCI_CFG register.  But the hardware allows that.
 */
static const struct blk_crypto_ll_ops cqhci_crypto_ops = …;

static enum blk_crypto_mode_num
cqhci_find_blk_crypto_mode(union cqhci_crypto_cap_entry cap)
{ … }

/**
 * cqhci_crypto_init - initialize CQHCI crypto support
 * @cq_host: a cqhci host
 *
 * If the driver previously set MMC_CAP2_CRYPTO and the CQE declares
 * CQHCI_CAP_CS, initialize the crypto support.  This involves reading the
 * crypto capability registers, initializing the blk_crypto_profile, clearing
 * all keyslots, and enabling 128-bit task descriptors.
 *
 * Return: 0 if crypto was initialized or isn't supported; whether
 *	   MMC_CAP2_CRYPTO remains set indicates which one of those cases it is.
 *	   Also can return a negative errno value on unexpected error.
 */
int cqhci_crypto_init(struct cqhci_host *cq_host)
{ … }