Re: [PATCH v2 4/9] mmc: cqhci: add support for inline encryption

[Satya Tangirala <satyat@google.com>]

On Sat, Dec 05, 2020 at 10:59:27AM +0000, Satya Tangirala wrote:
> On Wed, Dec 02, 2020 at 06:05:11PM -0800, Eric Biggers wrote:
> > From: Eric Biggers <ebiggers@google.com>
> > 
> > Add support for eMMC inline encryption using the blk-crypto framework
> > (Documentation/block/inline-encryption.rst).
> > 
> > eMMC inline encryption support is specified by the upcoming JEDEC eMMC
> > v5.2 specification.  It is only specified for the CQ interface, not the
> > non-CQ interface.  Although the eMMC v5.2 specification hasn't been
> > officially released yet, the crypto support was already agreed on
> > several years ago, and it was already implemented by at least two major
> > hardware vendors.  Lots of hardware in the field already supports and
> > uses it, e.g. Snapdragon 630 to give one example.
> > 
> > eMMC inline encryption support is very similar to the UFS inline
> > encryption support which was standardized in the UFS v2.1 specification
> > and was already upstreamed.  The only major difference is that eMMC
> > limits data unit numbers to 32 bits, unlike UFS's 64 bits.
> > 
> > Like we did with UFS, make the crypto support opt-in by individual
> > drivers; don't enable it automatically whenever the hardware declares
> > crypto support.  This is necessary because in every case we've seen,
> > some extra vendor-specific logic is needed to use the crypto support.
> > 
> > Co-developed-by: Satya Tangirala <satyat@google.com>
> > Signed-off-by: Satya Tangirala <satyat@google.com>
> > Signed-off-by: Eric Biggers <ebiggers@google.com>
> > ---
> >  drivers/mmc/host/Makefile       |   1 +
> >  drivers/mmc/host/cqhci-core.c   |  41 +++++-
> >  drivers/mmc/host/cqhci-crypto.c | 241 ++++++++++++++++++++++++++++++++
> >  drivers/mmc/host/cqhci-crypto.h |  47 +++++++
> >  drivers/mmc/host/cqhci.h        |  81 ++++++++++-
> >  5 files changed, 408 insertions(+), 3 deletions(-)
> >  create mode 100644 drivers/mmc/host/cqhci-crypto.c
> >  create mode 100644 drivers/mmc/host/cqhci-crypto.h
> > 
> > diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
> > index 20c2f9463d0dc..35158508ab63d 100644
> > --- a/drivers/mmc/host/Makefile
> > +++ b/drivers/mmc/host/Makefile
> > @@ -105,6 +105,7 @@ obj-$(CONFIG_MMC_SDHCI_OMAP)		+= sdhci-omap.o
> >  obj-$(CONFIG_MMC_SDHCI_SPRD)		+= sdhci-sprd.o
> >  obj-$(CONFIG_MMC_CQHCI)			+= cqhci.o
> >  cqhci-y					+= cqhci-core.o
> > +cqhci-$(CONFIG_MMC_CRYPTO)		+= cqhci-crypto.o
> >  obj-$(CONFIG_MMC_HSQ)			+= mmc_hsq.o
> >  
> >  ifeq ($(CONFIG_CB710_DEBUG),y)
> > diff --git a/drivers/mmc/host/cqhci-core.c b/drivers/mmc/host/cqhci-core.c
> > index ad7c9acff1728..93b0432bb6011 100644
> > --- a/drivers/mmc/host/cqhci-core.c
> > +++ b/drivers/mmc/host/cqhci-core.c
> > @@ -18,6 +18,7 @@
> >  #include <linux/mmc/card.h>
> >  
> >  #include "cqhci.h"
> > +#include "cqhci-crypto.h"
> >  
> >  #define DCMD_SLOT 31
> >  #define NUM_SLOTS 32
> > @@ -258,6 +259,9 @@ static void __cqhci_enable(struct cqhci_host *cq_host)
> >  	if (cq_host->caps & CQHCI_TASK_DESC_SZ_128)
> >  		cqcfg |= CQHCI_TASK_DESC_SZ;
> >  
> > +	if (mmc->caps2 & MMC_CAP2_CRYPTO)
> > +		cqcfg |= CQHCI_CRYPTO_GENERAL_ENABLE;
> > +
> >  	cqhci_writel(cq_host, cqcfg, CQHCI_CFG);
> >  
> >  	cqhci_writel(cq_host, lower_32_bits(cq_host->desc_dma_base),
> > @@ -430,7 +434,7 @@ static void cqhci_prep_task_desc(struct mmc_request *mrq,
> >  	task_desc[0] = cpu_to_le64(desc0);
> >  
> >  	if (cq_host->caps & CQHCI_TASK_DESC_SZ_128) {
> > -		u64 desc1 = 0;
> > +		u64 desc1 = cqhci_crypto_prep_task_desc(mrq);
> >  
> >  		task_desc[1] = cpu_to_le64(desc1);
> >  
> > @@ -681,6 +685,7 @@ static void cqhci_error_irq(struct mmc_host *mmc, u32 status, int cmd_error,
> >  	struct cqhci_host *cq_host = mmc->cqe_private;
> >  	struct cqhci_slot *slot;
> >  	u32 terri;
> > +	u32 tdpe;
> >  	int tag;
> >  
> >  	spin_lock(&cq_host->lock);
> > @@ -719,6 +724,30 @@ static void cqhci_error_irq(struct mmc_host *mmc, u32 status, int cmd_error,
> >  		}
> >  	}
> >  
> > +	/*
> > +	 * Handle ICCE ("Invalid Crypto Configuration Error").  This should
> > +	 * never happen, since the block layer ensures that all crypto-enabled
> > +	 * I/O requests have a valid keyslot before they reach the driver.
> > +	 *
> > +	 * Note that GCE ("General Crypto Error") is different; it already got
> > +	 * handled above by checking TERRI.
> > +	 */
> > +	if (status & CQHCI_IS_ICCE) {
> > +		tdpe = cqhci_readl(cq_host, CQHCI_TDPE);
> > +		WARN_ONCE(1,
> > +			  "%s: cqhci: invalid crypto configuration error. IRQ status: 0x%08x TDPE: 0x%08x\n",
> > +			  mmc_hostname(mmc), status, tdpe);
> > +		while (tdpe != 0) {
> > +			tag = __ffs(tdpe);
> > +			tdpe &= ~(1 << tag);
> > +			slot = &cq_host->slot[tag];
> > +			if (!slot->mrq)
> > +				continue;
> > +			slot->flags = cqhci_error_flags(data_error, cmd_error);
> > +			cqhci_recovery_needed(mmc, slot->mrq, true);
> > +		}
> > +	}
> > +
> >  	if (!cq_host->recovery_halt) {
> >  		/*
> >  		 * The only way to guarantee forward progress is to mark at
> > @@ -784,7 +813,8 @@ irqreturn_t cqhci_irq(struct mmc_host *mmc, u32 intmask, int cmd_error,
> >  
> >  	pr_debug("%s: cqhci: IRQ status: 0x%08x\n", mmc_hostname(mmc), status);
> >  
> > -	if ((status & CQHCI_IS_RED) || cmd_error || data_error)
> > +	if ((status & (CQHCI_IS_RED | CQHCI_IS_GCE | CQHCI_IS_ICCE)) ||
> > +	    cmd_error || data_error)
> >  		cqhci_error_irq(mmc, status, cmd_error, data_error);
> >  
> >  	if (status & CQHCI_IS_TCC) {
> > @@ -1151,6 +1181,13 @@ int cqhci_init(struct cqhci_host *cq_host, struct mmc_host *mmc,
> >  		goto out_err;
> >  	}
> >  
> > +	err = cqhci_crypto_init(cq_host);
> > +	if (err) {
> > +		pr_err("%s: CQHCI crypto initialization failed\n",
> > +		       mmc_hostname(mmc));
> > +		goto out_err;
> > +	}
> > +
> >  	spin_lock_init(&cq_host->lock);
> >  
> >  	init_completion(&cq_host->halt_comp);
> > diff --git a/drivers/mmc/host/cqhci-crypto.c b/drivers/mmc/host/cqhci-crypto.c
> > new file mode 100644
> > index 0000000000000..98f141c8480ce
> > --- /dev/null
> > +++ b/drivers/mmc/host/cqhci-crypto.c
> > @@ -0,0 +1,241 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * CQHCI crypto engine (inline encryption) support
> > + *
> > + * Copyright 2020 Google LLC
> > + */
> > +
> > +#include <linux/blk-crypto.h>
> > +#include <linux/keyslot-manager.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 {
> > +	enum cqhci_crypto_alg alg;
> > +	enum cqhci_crypto_key_size key_size;
> > +} cqhci_crypto_algs[BLK_ENCRYPTION_MODE_MAX] = {
> > +	[BLK_ENCRYPTION_MODE_AES_256_XTS] = {
> > +		.alg = CQHCI_CRYPTO_ALG_AES_XTS,
> > +		.key_size = CQHCI_CRYPTO_KEY_SIZE_256,
> > +	},
> > +};
> > +
> > +static inline struct cqhci_host *
> > +cqhci_host_from_ksm(struct blk_keyslot_manager *ksm)
> > +{
> > +	struct mmc_host *mmc = container_of(ksm, struct mmc_host, ksm);
> > +
> > +	return mmc->cqe_private;
> > +}
> > +
> > +static void cqhci_crypto_program_key(struct cqhci_host *cq_host,
> > +				     const union cqhci_crypto_cfg_entry *cfg,
> > +				     int slot)
> > +{
> > +	u32 slot_offset = cq_host->crypto_cfg_register + slot * sizeof(*cfg);
> > +	int i;
> > +
> > +	/* Clear CFGE */
> > +	cqhci_writel(cq_host, 0, slot_offset + 16 * sizeof(cfg->reg_val[0]));
> > +
> > +	/* Write the key */
> > +	for (i = 0; i < 16; i++) {
> > +		cqhci_writel(cq_host, le32_to_cpu(cfg->reg_val[i]),
> > +			     slot_offset + i * sizeof(cfg->reg_val[0]));
> > +	}
> > +	/* Write dword 17 */
> > +	cqhci_writel(cq_host, le32_to_cpu(cfg->reg_val[17]),
> > +		     slot_offset + 17 * sizeof(cfg->reg_val[0]));
> > +	/* Write dword 16, which includes the new value of CFGE */
> > +	cqhci_writel(cq_host, le32_to_cpu(cfg->reg_val[16]),
> > +		     slot_offset + 16 * sizeof(cfg->reg_val[0]));
> > +}
> > +
> > +static int cqhci_crypto_keyslot_program(struct blk_keyslot_manager *ksm,
> > +					const struct blk_crypto_key *key,
> > +					unsigned int slot)
> > +
> > +{
> > +	struct cqhci_host *cq_host = cqhci_host_from_ksm(ksm);
> > +	const union cqhci_crypto_cap_entry *ccap_array =
> > +		cq_host->crypto_cap_array;
> > +	const struct cqhci_crypto_alg_entry *alg =
> > +			&cqhci_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 cqhci_crypto_cfg_entry cfg = {};
> > +
> > +	BUILD_BUG_ON(CQHCI_CRYPTO_KEY_SIZE_INVALID != 0);
> > +	for (i = 0; i < cq_host->crypto_capabilities.num_crypto_cap; i++) {
> > +		if (ccap_array[i].algorithm_id == alg->alg &&
> > +		    ccap_array[i].key_size == alg->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 = CQHCI_CRYPTO_CONFIGURATION_ENABLE;
> > +
> > +	if (ccap_array[cap_idx].algorithm_id == CQHCI_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 + CQHCI_CRYPTO_KEY_MAX_SIZE/2,
> > +		       key->raw + key->size/2, key->size/2);
> > +	} else {
> > +		memcpy(cfg.crypto_key, key->raw, key->size);
> > +	}
> > +
> > +	cqhci_crypto_program_key(cq_host, &cfg, slot);
> > +
> > +	memzero_explicit(&cfg, sizeof(cfg));
> > +	return 0;
> > +}
> > +
> > +static void cqhci_crypto_clear_keyslot(struct cqhci_host *cq_host, int slot)
> > +{
> > +	/*
> > +	 * Clear the crypto cfg on the device. Clearing CFGE
> > +	 * might not be sufficient, so just clear the entire cfg.
> > +	 */
> > +	union cqhci_crypto_cfg_entry cfg = {};
> > +
> > +	cqhci_crypto_program_key(cq_host, &cfg, slot);
> > +}
> > +
> > +static int cqhci_crypto_keyslot_evict(struct blk_keyslot_manager *ksm,
> > +				      const struct blk_crypto_key *key,
> > +				      unsigned int slot)
> > +{
> > +	struct cqhci_host *cq_host = cqhci_host_from_ksm(ksm);
> > +
> > +	cqhci_crypto_clear_keyslot(cq_host, slot);
> > +	return 0;
> > +}
> > +
> > +/*
> > + * 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_ksm_ll_ops cqhci_ksm_ops = {
> > +	.keyslot_program	= cqhci_crypto_keyslot_program,
> > +	.keyslot_evict		= cqhci_crypto_keyslot_evict,
> > +};
> > +
> > +static enum blk_crypto_mode_num
> > +cqhci_find_blk_crypto_mode(union cqhci_crypto_cap_entry cap)
> > +{
> > +	int i;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(cqhci_crypto_algs); i++) {
> > +		BUILD_BUG_ON(CQHCI_CRYPTO_KEY_SIZE_INVALID != 0);
> > +		if (cqhci_crypto_algs[i].alg == cap.algorithm_id &&
> > +		    cqhci_crypto_algs[i].key_size == cap.key_size)
> > +			return i;
> > +	}
> > +	return BLK_ENCRYPTION_MODE_INVALID;
> > +}
> > +
> > +/**
> > + * 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 keyslot manager, 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)
> > +{
> > +	struct mmc_host *mmc = cq_host->mmc;
> > +	struct device *dev = mmc_dev(mmc);
> > +	struct blk_keyslot_manager *ksm = &mmc->ksm;
> > +	unsigned int num_keyslots;
> > +	unsigned int cap_idx;
> > +	enum blk_crypto_mode_num blk_mode_num;
> > +	unsigned int slot;
> > +	int err = 0;
> > +
> > +	if (!(mmc->caps2 & MMC_CAP2_CRYPTO) ||
> > +	    !(cqhci_readl(cq_host, CQHCI_CAP) & CQHCI_CAP_CS))
> > +		goto out;
> > +
> > +	cq_host->crypto_capabilities.reg_val =
> > +			cpu_to_le32(cqhci_readl(cq_host, CQHCI_CCAP));
> > +
> > +	cq_host->crypto_cfg_register =
> > +		(u32)cq_host->crypto_capabilities.config_array_ptr * 0x100;
> > +
> > +	cq_host->crypto_cap_array =
> > +		devm_kcalloc(dev, cq_host->crypto_capabilities.num_crypto_cap,
> > +			     sizeof(cq_host->crypto_cap_array[0]), GFP_KERNEL);
> > +	if (!cq_host->crypto_cap_array) {
> > +		err = -ENOMEM;
> > +		goto out;
> > +	}
> > +
> > +	/*
> > +	 * CCAP.CFGC is off by one, so the actual number of crypto
> > +	 * configurations (a.k.a. keyslots) is CCAP.CFGC + 1.
> > +	 */
> > +	num_keyslots = cq_host->crypto_capabilities.config_count + 1;
> > +
> > +	err = blk_ksm_init(ksm, num_keyslots);
> > +	if (err)
> > +		goto out_free_caps;
> > +
> > +	ksm->ksm_ll_ops = cqhci_ksm_ops;
> > +	ksm->dev = dev;
> > +
> > +	/* Unfortunately, CQHCI crypto only supports 32 DUN bits. */
> > +	ksm->max_dun_bytes_supported = 4;
> > +
> > +	/*
> > +	 * Cache all the crypto capabilities and advertise the supported crypto
> > +	 * modes and data unit sizes to the block layer.
> > +	 */
> > +	for (cap_idx = 0; cap_idx < cq_host->crypto_capabilities.num_crypto_cap;
> > +	     cap_idx++) {
> > +		cq_host->crypto_cap_array[cap_idx].reg_val =
> > +			cpu_to_le32(cqhci_readl(cq_host,
> > +						CQHCI_CRYPTOCAP +
> > +						cap_idx * sizeof(__le32)));
> > +		blk_mode_num = cqhci_find_blk_crypto_mode(
> > +					cq_host->crypto_cap_array[cap_idx]);
> > +		if (blk_mode_num == BLK_ENCRYPTION_MODE_INVALID)
> > +			continue;
> > +		ksm->crypto_modes_supported[blk_mode_num] |=
> > +			cq_host->crypto_cap_array[cap_idx].sdus_mask * 512;
> > +	}
> > +
> > +	/* Clear all the keyslots so that we start in a known state. */
> > +	for (slot = 0; slot < num_keyslots; slot++)
> > +		cqhci_crypto_clear_keyslot(cq_host, slot);
> > +
> > +	/* CQHCI crypto requires the use of 128-bit task descriptors. */
> > +	cq_host->caps |= CQHCI_TASK_DESC_SZ_128;
> > +
> > +	return 0;
> > +
> > +out_free_caps:
> > +	devm_kfree(dev, cq_host->crypto_cap_array);
> > +	cq_host->crypto_cap_array = NULL;
> > +out:
> > +	mmc->caps2 &= ~MMC_CAP2_CRYPTO;
> > +	return err;
> > +}
> > diff --git a/drivers/mmc/host/cqhci-crypto.h b/drivers/mmc/host/cqhci-crypto.h
> > new file mode 100644
> > index 0000000000000..60b58ee0e6256
> > --- /dev/null
> > +++ b/drivers/mmc/host/cqhci-crypto.h
> > @@ -0,0 +1,47 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * CQHCI crypto engine (inline encryption) support
> > + *
> > + * Copyright 2020 Google LLC
> > + */
> > +
> > +#ifndef LINUX_MMC_CQHCI_CRYPTO_H
> > +#define LINUX_MMC_CQHCI_CRYPTO_H
> > +
> > +#include <linux/mmc/host.h>
> > +
> > +#include "cqhci.h"
> > +
> > +#ifdef CONFIG_MMC_CRYPTO
> > +
> > +int cqhci_crypto_init(struct cqhci_host *host);
> > +
> > +/*
> > + * Returns the crypto bits that should be set in bits 64-127 of the
> > + * task descriptor.
> > + */
> > +static inline u64 cqhci_crypto_prep_task_desc(struct mmc_request *mrq)
> > +{
> > +	if (!mrq->crypto_enabled)
> > +		return 0;
> > +
> > +	return CQHCI_CRYPTO_ENABLE_BIT |
> > +	       CQHCI_CRYPTO_KEYSLOT(mrq->crypto_key_slot) |
> > +	       mrq->data_unit_num;
> > +}
> > +
> > +#else /* CONFIG_MMC_CRYPTO */
> > +
> > +static inline int cqhci_crypto_init(struct cqhci_host *host)
> > +{
> > +	return 0;
> > +}
> > +
> > +static inline u64 cqhci_crypto_prep_task_desc(struct mmc_request *mrq)
> > +{
> > +	return 0;
> > +}
> > +
> > +#endif /* !CONFIG_MMC_CRYPTO */
> > +
> > +#endif /* LINUX_MMC_CQHCI_CRYPTO_H */
> > diff --git a/drivers/mmc/host/cqhci.h b/drivers/mmc/host/cqhci.h
> > index 89bf6adbce8ca..5c18734624fea 100644
> > --- a/drivers/mmc/host/cqhci.h
> > +++ b/drivers/mmc/host/cqhci.h
> > @@ -22,10 +22,13 @@
> >  
> >  /* capabilities */
> >  #define CQHCI_CAP			0x04
> > +#define CQHCI_CAP_CS			0x10000000 /* Crypto Support */
> > +
> >  /* configuration */
> >  #define CQHCI_CFG			0x08
> >  #define CQHCI_DCMD			0x00001000
> >  #define CQHCI_TASK_DESC_SZ		0x00000100
> > +#define CQHCI_CRYPTO_GENERAL_ENABLE	0x00000002
> >  #define CQHCI_ENABLE			0x00000001
> >  
> >  /* control */
> > @@ -39,8 +42,11 @@
> >  #define CQHCI_IS_TCC			BIT(1)
> >  #define CQHCI_IS_RED			BIT(2)
> >  #define CQHCI_IS_TCL			BIT(3)
> > +#define CQHCI_IS_GCE			BIT(4) /* General Crypto Error */
> > +#define CQHCI_IS_ICCE			BIT(5) /* Invalid Crypto Config Error */
> >  
> > -#define CQHCI_IS_MASK (CQHCI_IS_TCC | CQHCI_IS_RED)
> > +#define CQHCI_IS_MASK (CQHCI_IS_TCC | CQHCI_IS_RED | \
> > +		       CQHCI_IS_GCE | CQHCI_IS_ICCE)
> >  
> >  /* interrupt status enable */
> >  #define CQHCI_ISTE			0x14
> > @@ -78,6 +84,9 @@
> >  /* task clear */
> >  #define CQHCI_TCLR			0x38
> >  
> > +/* task descriptor processing error */
> > +#define CQHCI_TDPE			0x3c
> > +
> >  /* send status config 1 */
> >  #define CQHCI_SSC1			0x40
> >  #define CQHCI_SSC1_CBC_MASK		GENMASK(19, 16)
> > @@ -107,6 +116,10 @@
> >  /* command response argument */
> >  #define CQHCI_CRA			0x5C
> >  
> > +/* crypto capabilities */
> > +#define CQHCI_CCAP			0x100
> > +#define CQHCI_CRYPTOCAP			0x104
> > +
> >  #define CQHCI_INT_ALL			0xF
> >  #define CQHCI_IC_DEFAULT_ICCTH		31
> >  #define CQHCI_IC_DEFAULT_ICTOVAL	1
> > @@ -133,11 +146,71 @@
> >  #define CQHCI_CMD_TIMING(x)		(((x) & 1) << 22)
> >  #define CQHCI_RESP_TYPE(x)		(((x) & 0x3) << 23)
> >  
> > +/* crypto task descriptor fields (for bits 64-127 of task descriptor) */
> > +#define CQHCI_CRYPTO_ENABLE_BIT		(1ULL << 47)
> > +#define CQHCI_CRYPTO_KEYSLOT(x)		((u64)(x) << 32)
> > +
> >  /* transfer descriptor fields */
> >  #define CQHCI_DAT_LENGTH(x)		(((x) & 0xFFFF) << 16)
> >  #define CQHCI_DAT_ADDR_LO(x)		(((x) & 0xFFFFFFFF) << 32)
> >  #define CQHCI_DAT_ADDR_HI(x)		(((x) & 0xFFFFFFFF) << 0)
> >  
> > +/* CCAP - Crypto Capability 100h */
> > +union cqhci_crypto_capabilities {
> > +	__le32 reg_val;
> > +	struct {
> > +		u8 num_crypto_cap;
> > +		u8 config_count;
> > +		u8 reserved;
> > +		u8 config_array_ptr;
> > +	};
> > +};
> > +
> > +enum cqhci_crypto_key_size {
> > +	CQHCI_CRYPTO_KEY_SIZE_INVALID	= 0,
> > +	CQHCI_CRYPTO_KEY_SIZE_128	= 1,
> > +	CQHCI_CRYPTO_KEY_SIZE_192	= 2,
> > +	CQHCI_CRYPTO_KEY_SIZE_256	= 3,
> > +	CQHCI_CRYPTO_KEY_SIZE_512	= 4,
> > +};
> > +
> > +enum cqhci_crypto_alg {
> > +	CQHCI_CRYPTO_ALG_AES_XTS		= 0,
> > +	CQHCI_CRYPTO_ALG_BITLOCKER_AES_CBC	= 1,
> > +	CQHCI_CRYPTO_ALG_AES_ECB		= 2,
> > +	CQHCI_CRYPTO_ALG_ESSIV_AES_CBC		= 3,
> > +};
> > +
> > +/* x-CRYPTOCAP - Crypto Capability X */
> > +union cqhci_crypto_cap_entry {
> > +	__le32 reg_val;
> > +	struct {
> > +		u8 algorithm_id;
> > +		u8 sdus_mask; /* Supported data unit size mask */
> > +		u8 key_size;
> > +		u8 reserved;
> > +	};
> > +};
> > +
> > +#define CQHCI_CRYPTO_CONFIGURATION_ENABLE (1 << 7)
> > +#define CQHCI_CRYPTO_KEY_MAX_SIZE 64
> > +/* x-CRYPTOCFG - Crypto Configuration X */
> > +union cqhci_crypto_cfg_entry {
> > +	__le32 reg_val[32];
> > +	struct {
> > +		u8 crypto_key[CQHCI_CRYPTO_KEY_MAX_SIZE];
> > +		/* 4KB/512 = 8 */
> > +		u8 data_unit_size;
> > +		u8 crypto_cap_idx;
> > +		u8 reserved_1;
> > +		u8 config_enable;
> > +		u8 reserved_multi_host;
> > +		u8 reserved_2;
> > +		u8 vsb[2];
> > +		u8 reserved_3[56];
> > +	};
> > +};
> > +
> >  struct cqhci_host_ops;
> >  struct mmc_host;
> >  struct mmc_request;
> > @@ -196,6 +269,12 @@ struct cqhci_host {
> >  	struct completion halt_comp;
> >  	wait_queue_head_t wait_queue;
> >  	struct cqhci_slot *slot;
> > +
> > +#ifdef CONFIG_MMC_CRYPTO
> > +	union cqhci_crypto_capabilities crypto_capabilities;
> > +	union cqhci_crypto_cap_entry *crypto_cap_array;
> > +	u32 crypto_cfg_register;
> > +#endif
> >  };
> >  
> >  struct cqhci_host_ops {
> > -- 
> > 2.29.2
> > 
> The version of code from Qualcomm on AOSP reprogrammed all keyslots from
> cqhci_recovery_finish(). I notice that this patch drops that - I'm guessing
> that was intentional? Other than that, this patch looks good to me :).
For reference, the code I'm referring to is at
https://android-review.googlesource.com/c/kernel/common/+/1269702/9