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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /block/blk-crypto.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'block/blk-crypto.c')
-rw-r--r--block/blk-crypto.c428
1 files changed, 428 insertions, 0 deletions
diff --git a/block/blk-crypto.c b/block/blk-crypto.c
new file mode 100644
index 000000000..453785861
--- /dev/null
+++ b/block/blk-crypto.c
@@ -0,0 +1,428 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 Google LLC
+ */
+
+/*
+ * Refer to Documentation/block/inline-encryption.rst for detailed explanation.
+ */
+
+#define pr_fmt(fmt) "blk-crypto: " fmt
+
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/blk-crypto-profile.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include "blk-crypto-internal.h"
+
+const struct blk_crypto_mode blk_crypto_modes[] = {
+ [BLK_ENCRYPTION_MODE_AES_256_XTS] = {
+ .name = "AES-256-XTS",
+ .cipher_str = "xts(aes)",
+ .keysize = 64,
+ .ivsize = 16,
+ },
+ [BLK_ENCRYPTION_MODE_AES_128_CBC_ESSIV] = {
+ .name = "AES-128-CBC-ESSIV",
+ .cipher_str = "essiv(cbc(aes),sha256)",
+ .keysize = 16,
+ .ivsize = 16,
+ },
+ [BLK_ENCRYPTION_MODE_ADIANTUM] = {
+ .name = "Adiantum",
+ .cipher_str = "adiantum(xchacha12,aes)",
+ .keysize = 32,
+ .ivsize = 32,
+ },
+ [BLK_ENCRYPTION_MODE_SM4_XTS] = {
+ .name = "SM4-XTS",
+ .cipher_str = "xts(sm4)",
+ .keysize = 32,
+ .ivsize = 16,
+ },
+};
+
+/*
+ * This number needs to be at least (the number of threads doing IO
+ * concurrently) * (maximum recursive depth of a bio), so that we don't
+ * deadlock on crypt_ctx allocations. The default is chosen to be the same
+ * as the default number of post read contexts in both EXT4 and F2FS.
+ */
+static int num_prealloc_crypt_ctxs = 128;
+
+module_param(num_prealloc_crypt_ctxs, int, 0444);
+MODULE_PARM_DESC(num_prealloc_crypt_ctxs,
+ "Number of bio crypto contexts to preallocate");
+
+static struct kmem_cache *bio_crypt_ctx_cache;
+static mempool_t *bio_crypt_ctx_pool;
+
+static int __init bio_crypt_ctx_init(void)
+{
+ size_t i;
+
+ bio_crypt_ctx_cache = KMEM_CACHE(bio_crypt_ctx, 0);
+ if (!bio_crypt_ctx_cache)
+ goto out_no_mem;
+
+ bio_crypt_ctx_pool = mempool_create_slab_pool(num_prealloc_crypt_ctxs,
+ bio_crypt_ctx_cache);
+ if (!bio_crypt_ctx_pool)
+ goto out_no_mem;
+
+ /* This is assumed in various places. */
+ BUILD_BUG_ON(BLK_ENCRYPTION_MODE_INVALID != 0);
+
+ /* Sanity check that no algorithm exceeds the defined limits. */
+ for (i = 0; i < BLK_ENCRYPTION_MODE_MAX; i++) {
+ BUG_ON(blk_crypto_modes[i].keysize > BLK_CRYPTO_MAX_KEY_SIZE);
+ BUG_ON(blk_crypto_modes[i].ivsize > BLK_CRYPTO_MAX_IV_SIZE);
+ }
+
+ return 0;
+out_no_mem:
+ panic("Failed to allocate mem for bio crypt ctxs\n");
+}
+subsys_initcall(bio_crypt_ctx_init);
+
+void bio_crypt_set_ctx(struct bio *bio, const struct blk_crypto_key *key,
+ const u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE], gfp_t gfp_mask)
+{
+ struct bio_crypt_ctx *bc;
+
+ /*
+ * The caller must use a gfp_mask that contains __GFP_DIRECT_RECLAIM so
+ * that the mempool_alloc() can't fail.
+ */
+ WARN_ON_ONCE(!(gfp_mask & __GFP_DIRECT_RECLAIM));
+
+ bc = mempool_alloc(bio_crypt_ctx_pool, gfp_mask);
+
+ bc->bc_key = key;
+ memcpy(bc->bc_dun, dun, sizeof(bc->bc_dun));
+
+ bio->bi_crypt_context = bc;
+}
+
+void __bio_crypt_free_ctx(struct bio *bio)
+{
+ mempool_free(bio->bi_crypt_context, bio_crypt_ctx_pool);
+ bio->bi_crypt_context = NULL;
+}
+
+int __bio_crypt_clone(struct bio *dst, struct bio *src, gfp_t gfp_mask)
+{
+ dst->bi_crypt_context = mempool_alloc(bio_crypt_ctx_pool, gfp_mask);
+ if (!dst->bi_crypt_context)
+ return -ENOMEM;
+ *dst->bi_crypt_context = *src->bi_crypt_context;
+ return 0;
+}
+
+/* Increments @dun by @inc, treating @dun as a multi-limb integer. */
+void bio_crypt_dun_increment(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
+ unsigned int inc)
+{
+ int i;
+
+ for (i = 0; inc && i < BLK_CRYPTO_DUN_ARRAY_SIZE; i++) {
+ dun[i] += inc;
+ /*
+ * If the addition in this limb overflowed, then we need to
+ * carry 1 into the next limb. Else the carry is 0.
+ */
+ if (dun[i] < inc)
+ inc = 1;
+ else
+ inc = 0;
+ }
+}
+
+void __bio_crypt_advance(struct bio *bio, unsigned int bytes)
+{
+ struct bio_crypt_ctx *bc = bio->bi_crypt_context;
+
+ bio_crypt_dun_increment(bc->bc_dun,
+ bytes >> bc->bc_key->data_unit_size_bits);
+}
+
+/*
+ * Returns true if @bc->bc_dun plus @bytes converted to data units is equal to
+ * @next_dun, treating the DUNs as multi-limb integers.
+ */
+bool bio_crypt_dun_is_contiguous(const struct bio_crypt_ctx *bc,
+ unsigned int bytes,
+ const u64 next_dun[BLK_CRYPTO_DUN_ARRAY_SIZE])
+{
+ int i;
+ unsigned int carry = bytes >> bc->bc_key->data_unit_size_bits;
+
+ for (i = 0; i < BLK_CRYPTO_DUN_ARRAY_SIZE; i++) {
+ if (bc->bc_dun[i] + carry != next_dun[i])
+ return false;
+ /*
+ * If the addition in this limb overflowed, then we need to
+ * carry 1 into the next limb. Else the carry is 0.
+ */
+ if ((bc->bc_dun[i] + carry) < carry)
+ carry = 1;
+ else
+ carry = 0;
+ }
+
+ /* If the DUN wrapped through 0, don't treat it as contiguous. */
+ return carry == 0;
+}
+
+/*
+ * Checks that two bio crypt contexts are compatible - i.e. that
+ * they are mergeable except for data_unit_num continuity.
+ */
+static bool bio_crypt_ctx_compatible(struct bio_crypt_ctx *bc1,
+ struct bio_crypt_ctx *bc2)
+{
+ if (!bc1)
+ return !bc2;
+
+ return bc2 && bc1->bc_key == bc2->bc_key;
+}
+
+bool bio_crypt_rq_ctx_compatible(struct request *rq, struct bio *bio)
+{
+ return bio_crypt_ctx_compatible(rq->crypt_ctx, bio->bi_crypt_context);
+}
+
+/*
+ * Checks that two bio crypt contexts are compatible, and also
+ * that their data_unit_nums are continuous (and can hence be merged)
+ * in the order @bc1 followed by @bc2.
+ */
+bool bio_crypt_ctx_mergeable(struct bio_crypt_ctx *bc1, unsigned int bc1_bytes,
+ struct bio_crypt_ctx *bc2)
+{
+ if (!bio_crypt_ctx_compatible(bc1, bc2))
+ return false;
+
+ return !bc1 || bio_crypt_dun_is_contiguous(bc1, bc1_bytes, bc2->bc_dun);
+}
+
+/* Check that all I/O segments are data unit aligned. */
+static bool bio_crypt_check_alignment(struct bio *bio)
+{
+ const unsigned int data_unit_size =
+ bio->bi_crypt_context->bc_key->crypto_cfg.data_unit_size;
+ struct bvec_iter iter;
+ struct bio_vec bv;
+
+ bio_for_each_segment(bv, bio, iter) {
+ if (!IS_ALIGNED(bv.bv_len | bv.bv_offset, data_unit_size))
+ return false;
+ }
+
+ return true;
+}
+
+blk_status_t __blk_crypto_init_request(struct request *rq)
+{
+ return blk_crypto_get_keyslot(rq->q->crypto_profile,
+ rq->crypt_ctx->bc_key,
+ &rq->crypt_keyslot);
+}
+
+/**
+ * __blk_crypto_free_request - Uninitialize the crypto fields of a request.
+ *
+ * @rq: The request whose crypto fields to uninitialize.
+ *
+ * Completely uninitializes the crypto fields of a request. If a keyslot has
+ * been programmed into some inline encryption hardware, that keyslot is
+ * released. The rq->crypt_ctx is also freed.
+ */
+void __blk_crypto_free_request(struct request *rq)
+{
+ blk_crypto_put_keyslot(rq->crypt_keyslot);
+ mempool_free(rq->crypt_ctx, bio_crypt_ctx_pool);
+ blk_crypto_rq_set_defaults(rq);
+}
+
+/**
+ * __blk_crypto_bio_prep - Prepare bio for inline encryption
+ *
+ * @bio_ptr: pointer to original bio pointer
+ *
+ * If the bio crypt context provided for the bio is supported by the underlying
+ * device's inline encryption hardware, do nothing.
+ *
+ * Otherwise, try to perform en/decryption for this bio by falling back to the
+ * kernel crypto API. When the crypto API fallback is used for encryption,
+ * blk-crypto may choose to split the bio into 2 - the first one that will
+ * continue to be processed and the second one that will be resubmitted via
+ * submit_bio_noacct. A bounce bio will be allocated to encrypt the contents
+ * of the aforementioned "first one", and *bio_ptr will be updated to this
+ * bounce bio.
+ *
+ * Caller must ensure bio has bio_crypt_ctx.
+ *
+ * Return: true on success; false on error (and bio->bi_status will be set
+ * appropriately, and bio_endio() will have been called so bio
+ * submission should abort).
+ */
+bool __blk_crypto_bio_prep(struct bio **bio_ptr)
+{
+ struct bio *bio = *bio_ptr;
+ const struct blk_crypto_key *bc_key = bio->bi_crypt_context->bc_key;
+
+ /* Error if bio has no data. */
+ if (WARN_ON_ONCE(!bio_has_data(bio))) {
+ bio->bi_status = BLK_STS_IOERR;
+ goto fail;
+ }
+
+ if (!bio_crypt_check_alignment(bio)) {
+ bio->bi_status = BLK_STS_IOERR;
+ goto fail;
+ }
+
+ /*
+ * Success if device supports the encryption context, or if we succeeded
+ * in falling back to the crypto API.
+ */
+ if (blk_crypto_config_supported_natively(bio->bi_bdev,
+ &bc_key->crypto_cfg))
+ return true;
+ if (blk_crypto_fallback_bio_prep(bio_ptr))
+ return true;
+fail:
+ bio_endio(*bio_ptr);
+ return false;
+}
+
+int __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio,
+ gfp_t gfp_mask)
+{
+ if (!rq->crypt_ctx) {
+ rq->crypt_ctx = mempool_alloc(bio_crypt_ctx_pool, gfp_mask);
+ if (!rq->crypt_ctx)
+ return -ENOMEM;
+ }
+ *rq->crypt_ctx = *bio->bi_crypt_context;
+ return 0;
+}
+
+/**
+ * blk_crypto_init_key() - Prepare a key for use with blk-crypto
+ * @blk_key: Pointer to the blk_crypto_key to initialize.
+ * @raw_key: Pointer to the raw key. Must be the correct length for the chosen
+ * @crypto_mode; see blk_crypto_modes[].
+ * @crypto_mode: identifier for the encryption algorithm to use
+ * @dun_bytes: number of bytes that will be used to specify the DUN when this
+ * key is used
+ * @data_unit_size: the data unit size to use for en/decryption
+ *
+ * Return: 0 on success, -errno on failure. The caller is responsible for
+ * zeroizing both blk_key and raw_key when done with them.
+ */
+int blk_crypto_init_key(struct blk_crypto_key *blk_key, const u8 *raw_key,
+ enum blk_crypto_mode_num crypto_mode,
+ unsigned int dun_bytes,
+ unsigned int data_unit_size)
+{
+ const struct blk_crypto_mode *mode;
+
+ memset(blk_key, 0, sizeof(*blk_key));
+
+ if (crypto_mode >= ARRAY_SIZE(blk_crypto_modes))
+ return -EINVAL;
+
+ mode = &blk_crypto_modes[crypto_mode];
+ if (mode->keysize == 0)
+ return -EINVAL;
+
+ if (dun_bytes == 0 || dun_bytes > mode->ivsize)
+ return -EINVAL;
+
+ if (!is_power_of_2(data_unit_size))
+ return -EINVAL;
+
+ blk_key->crypto_cfg.crypto_mode = crypto_mode;
+ blk_key->crypto_cfg.dun_bytes = dun_bytes;
+ blk_key->crypto_cfg.data_unit_size = data_unit_size;
+ blk_key->data_unit_size_bits = ilog2(data_unit_size);
+ blk_key->size = mode->keysize;
+ memcpy(blk_key->raw, raw_key, mode->keysize);
+
+ return 0;
+}
+
+bool blk_crypto_config_supported_natively(struct block_device *bdev,
+ const struct blk_crypto_config *cfg)
+{
+ return __blk_crypto_cfg_supported(bdev_get_queue(bdev)->crypto_profile,
+ cfg);
+}
+
+/*
+ * Check if bios with @cfg can be en/decrypted by blk-crypto (i.e. either the
+ * block_device it's submitted to supports inline crypto, or the
+ * blk-crypto-fallback is enabled and supports the cfg).
+ */
+bool blk_crypto_config_supported(struct block_device *bdev,
+ const struct blk_crypto_config *cfg)
+{
+ return IS_ENABLED(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK) ||
+ blk_crypto_config_supported_natively(bdev, cfg);
+}
+
+/**
+ * blk_crypto_start_using_key() - Start using a blk_crypto_key on a device
+ * @bdev: block device to operate on
+ * @key: A key to use on the device
+ *
+ * Upper layers must call this function to ensure that either the hardware
+ * supports the key's crypto settings, or the crypto API fallback has transforms
+ * for the needed mode allocated and ready to go. This function may allocate
+ * an skcipher, and *should not* be called from the data path, since that might
+ * cause a deadlock
+ *
+ * Return: 0 on success; -ENOPKG if the hardware doesn't support the key and
+ * blk-crypto-fallback is either disabled or the needed algorithm
+ * is disabled in the crypto API; or another -errno code.
+ */
+int blk_crypto_start_using_key(struct block_device *bdev,
+ const struct blk_crypto_key *key)
+{
+ if (blk_crypto_config_supported_natively(bdev, &key->crypto_cfg))
+ return 0;
+ return blk_crypto_fallback_start_using_mode(key->crypto_cfg.crypto_mode);
+}
+
+/**
+ * blk_crypto_evict_key() - Evict a key from any inline encryption hardware
+ * it may have been programmed into
+ * @bdev: The block_device who's associated inline encryption hardware this key
+ * might have been programmed into
+ * @key: The key to evict
+ *
+ * Upper layers (filesystems) must call this function to ensure that a key is
+ * evicted from any hardware that it might have been programmed into. The key
+ * must not be in use by any in-flight IO when this function is called.
+ *
+ * Return: 0 on success or if the key wasn't in any keyslot; -errno on error.
+ */
+int blk_crypto_evict_key(struct block_device *bdev,
+ const struct blk_crypto_key *key)
+{
+ struct request_queue *q = bdev_get_queue(bdev);
+
+ if (blk_crypto_config_supported_natively(bdev, &key->crypto_cfg))
+ return __blk_crypto_evict_key(q->crypto_profile, key);
+
+ /*
+ * If the block_device didn't support the key, then blk-crypto-fallback
+ * may have been used, so try to evict the key from blk-crypto-fallback.
+ */
+ return blk_crypto_fallback_evict_key(key);
+}
+EXPORT_SYMBOL_GPL(blk_crypto_evict_key);