mmc: sdhci-msm: convert to use custom crypto profile

As is being done in ufs-qcom, make the sdhci-msm driver override the
full crypto profile rather than "just" key programming and eviction.
This makes it much more straightforward to add support for
hardware-wrapped inline encryption keys.  It also makes it easy to pass
the original blk_crypto_key down to qcom_ice_program_key() once it is
updated to require the key in that form.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Message-ID: <20241213041958.202565-8-ebiggers@kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Author: ebiggers

drivers/mmc/host/cqhci-crypto.c

@@ -28,16 +28,13 @@ cqhci_host_from_crypto_profile(struct blk_crypto_profile *profile)
 	return mmc_from_crypto_profile(profile)->cqe_private;
 }
 
-static int cqhci_crypto_program_key(struct cqhci_host *cq_host,
-				    const union cqhci_crypto_cfg_entry *cfg,
-				    int slot)
+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;
 
-	if (cq_host->ops->program_key)
-		return cq_host->ops->program_key(cq_host, cfg, slot);
-
 	/* Clear CFGE */
 	cqhci_writel(cq_host, 0, slot_offset + 16 * sizeof(cfg->reg_val[0]));
 
@@ -52,7 +49,6 @@ static int cqhci_crypto_program_key(struct cqhci_host *cq_host,
 	/* 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]));
-	return 0;
 }
 
 static int cqhci_crypto_keyslot_program(struct blk_crypto_profile *profile,
@@ -69,7 +65,6 @@ static int cqhci_crypto_keyslot_program(struct blk_crypto_profile *profile,
 	int i;
 	int cap_idx = -1;
 	union cqhci_crypto_cfg_entry cfg = {};
-	int err;
 
 	BUILD_BUG_ON(CQHCI_CRYPTO_KEY_SIZE_INVALID != 0);
 	for (i = 0; i < cq_host->crypto_capabilities.num_crypto_cap; i++) {
@@ -96,10 +91,10 @@ static int cqhci_crypto_keyslot_program(struct blk_crypto_profile *profile,
 		memcpy(cfg.crypto_key, key->raw, key->size);
 	}
 
-	err = cqhci_crypto_program_key(cq_host, &cfg, slot);
+	cqhci_crypto_program_key(cq_host, &cfg, slot);
 
 	memzero_explicit(&cfg, sizeof(cfg));
-	return err;
+	return 0;
 }
 
 static int cqhci_crypto_clear_keyslot(struct cqhci_host *cq_host, int slot)
@@ -110,7 +105,8 @@ static int cqhci_crypto_clear_keyslot(struct cqhci_host *cq_host, int slot)
 	 */
 	union cqhci_crypto_cfg_entry cfg = {};
 
-	return cqhci_crypto_program_key(cq_host, &cfg, slot);
+	cqhci_crypto_program_key(cq_host, &cfg, slot);
+	return 0;
 }
 
 static int cqhci_crypto_keyslot_evict(struct blk_crypto_profile *profile,
@@ -167,7 +163,6 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
 	struct mmc_host *mmc = cq_host->mmc;
 	struct device *dev = mmc_dev(mmc);
 	struct blk_crypto_profile *profile = &mmc->crypto_profile;
-	unsigned int num_keyslots;
 	unsigned int cap_idx;
 	enum blk_crypto_mode_num blk_mode_num;
 	unsigned int slot;
@@ -177,6 +172,9 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
 	    !(cqhci_readl(cq_host, CQHCI_CAP) & CQHCI_CAP_CS))
 		goto out;
 
+	if (cq_host->ops->uses_custom_crypto_profile)
+		goto profile_initialized;
+
 	cq_host->crypto_capabilities.reg_val =
 			cpu_to_le32(cqhci_readl(cq_host, CQHCI_CCAP));
 
@@ -195,9 +193,8 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
 	 * 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 = devm_blk_crypto_profile_init(dev, profile, num_keyslots);
+	err = devm_blk_crypto_profile_init(
+		dev, profile, cq_host->crypto_capabilities.config_count + 1);
 	if (err)
 		goto out;
 
@@ -225,9 +222,11 @@ int cqhci_crypto_init(struct cqhci_host *cq_host)
 			cq_host->crypto_cap_array[cap_idx].sdus_mask * 512;
 	}
 
+profile_initialized:
+
 	/* 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);
+	for (slot = 0; slot < profile->num_slots; slot++)
+		profile->ll_ops.keyslot_evict(profile, NULL, slot);
 
 	/* CQHCI crypto requires the use of 128-bit task descriptors. */
 	cq_host->caps |= CQHCI_TASK_DESC_SZ_128;

drivers/mmc/host/cqhci.h

@@ -289,13 +289,11 @@ struct cqhci_host_ops {
 				 u64 *data);
 	void (*pre_enable)(struct mmc_host *mmc);
 	void (*post_disable)(struct mmc_host *mmc);
-#ifdef CONFIG_MMC_CRYPTO
-	int (*program_key)(struct cqhci_host *cq_host,
-			   const union cqhci_crypto_cfg_entry *cfg, int slot);
-#endif
 	void (*set_tran_desc)(struct cqhci_host *cq_host, u8 **desc,
 			      dma_addr_t addr, int len, bool end, bool dma64);
-
+#ifdef CONFIG_MMC_CRYPTO
+	bool uses_custom_crypto_profile;
+#endif
 };
 
 static inline void cqhci_writel(struct cqhci_host *host, u32 val, int reg)

drivers/mmc/host/sdhci-msm.c

@@ -1807,12 +1807,19 @@ static void sdhci_msm_set_clock(struct sdhci_host *host, unsigned int clock)
 
 #ifdef CONFIG_MMC_CRYPTO
 
+static const struct blk_crypto_ll_ops sdhci_msm_crypto_ops; /* forward decl */
+
 static int sdhci_msm_ice_init(struct sdhci_msm_host *msm_host,
 			      struct cqhci_host *cq_host)
 {
 	struct mmc_host *mmc = msm_host->mmc;
+	struct blk_crypto_profile *profile = &mmc->crypto_profile;
 	struct device *dev = mmc_dev(mmc);
 	struct qcom_ice *ice;
+	union cqhci_crypto_capabilities caps;
+	union cqhci_crypto_cap_entry cap;
+	int err;
+	int i;
 
 	if (!(cqhci_readl(cq_host, CQHCI_CAP) & CQHCI_CAP_CS))
 		return 0;
@@ -1827,8 +1834,37 @@ static int sdhci_msm_ice_init(struct sdhci_msm_host *msm_host,
 		return PTR_ERR_OR_ZERO(ice);
 
 	msm_host->ice = ice;
-	mmc->caps2 |= MMC_CAP2_CRYPTO;
 
+	/* Initialize the blk_crypto_profile */
+
+	caps.reg_val = cpu_to_le32(cqhci_readl(cq_host, CQHCI_CCAP));
+
+	/* The number of keyslots supported is (CFGC+1) */
+	err = devm_blk_crypto_profile_init(dev, profile, caps.config_count + 1);
+	if (err)
+		return err;
+
+	profile->ll_ops = sdhci_msm_crypto_ops;
+	profile->max_dun_bytes_supported = 4;
+	profile->dev = dev;
+
+	/*
+	 * Currently this driver only supports AES-256-XTS.  All known versions
+	 * of ICE support it, but to be safe make sure it is really declared in
+	 * the crypto capability registers.  The crypto capability registers
+	 * also give the supported data unit size(s).
+	 */
+	for (i = 0; i < caps.num_crypto_cap; i++) {
+		cap.reg_val = cpu_to_le32(cqhci_readl(cq_host,
+						      CQHCI_CRYPTOCAP +
+						      i * sizeof(__le32)));
+		if (cap.algorithm_id == CQHCI_CRYPTO_ALG_AES_XTS &&
+		    cap.key_size == CQHCI_CRYPTO_KEY_SIZE_256)
+			profile->modes_supported[BLK_ENCRYPTION_MODE_AES_256_XTS] |=
+				cap.sdus_mask * 512;
+	}
+
+	mmc->caps2 |= MMC_CAP2_CRYPTO;
 	return 0;
 }
 
@@ -1854,35 +1890,55 @@ static __maybe_unused int sdhci_msm_ice_suspend(struct sdhci_msm_host *msm_host)
 	return 0;
 }
 
-/*
- * Program a key into a QC ICE keyslot, or evict a keyslot.  QC ICE requires
- * vendor-specific SCM calls for this; it doesn't support the standard way.
- */
-static int sdhci_msm_program_key(struct cqhci_host *cq_host,
-				 const union cqhci_crypto_cfg_entry *cfg,
-				 int slot)
+static inline struct sdhci_msm_host *
+sdhci_msm_host_from_crypto_profile(struct blk_crypto_profile *profile)
 {
-	struct sdhci_host *host = mmc_priv(cq_host->mmc);
+	struct mmc_host *mmc = mmc_from_crypto_profile(profile);
+	struct sdhci_host *host = mmc_priv(mmc);
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
-	union cqhci_crypto_cap_entry cap;
 
-	if (!(cfg->config_enable & CQHCI_CRYPTO_CONFIGURATION_ENABLE))
-		return qcom_ice_evict_key(msm_host->ice, slot);
+	return msm_host;
+}
+
+/*
+ * Program a key into a QC ICE keyslot.  QC ICE requires a QC-specific SCM call
+ * for this; it doesn't support the standard way.
+ */
+static int sdhci_msm_ice_keyslot_program(struct blk_crypto_profile *profile,
+					 const struct blk_crypto_key *key,
+					 unsigned int slot)
+{
+	struct sdhci_msm_host *msm_host =
+		sdhci_msm_host_from_crypto_profile(profile);
 
 	/* Only AES-256-XTS has been tested so far. */
-	cap = cq_host->crypto_cap_array[cfg->crypto_cap_idx];
-	if (cap.algorithm_id != CQHCI_CRYPTO_ALG_AES_XTS ||
-		cap.key_size != CQHCI_CRYPTO_KEY_SIZE_256)
-		return -EINVAL;
+	if (key->crypto_cfg.crypto_mode != BLK_ENCRYPTION_MODE_AES_256_XTS)
+		return -EOPNOTSUPP;
 
 	return qcom_ice_program_key(msm_host->ice,
 				    QCOM_ICE_CRYPTO_ALG_AES_XTS,
 				    QCOM_ICE_CRYPTO_KEY_SIZE_256,
-				    cfg->crypto_key,
-				    cfg->data_unit_size, slot);
+				    key->raw,
+				    key->crypto_cfg.data_unit_size / 512,
+				    slot);
 }
 
+static int sdhci_msm_ice_keyslot_evict(struct blk_crypto_profile *profile,
+				       const struct blk_crypto_key *key,
+				       unsigned int slot)
+{
+	struct sdhci_msm_host *msm_host =
+		sdhci_msm_host_from_crypto_profile(profile);
+
+	return qcom_ice_evict_key(msm_host->ice, slot);
+}
+
+static const struct blk_crypto_ll_ops sdhci_msm_crypto_ops = {
+	.keyslot_program	= sdhci_msm_ice_keyslot_program,
+	.keyslot_evict		= sdhci_msm_ice_keyslot_evict,
+};
+
 #else /* CONFIG_MMC_CRYPTO */
 
 static inline int sdhci_msm_ice_init(struct sdhci_msm_host *msm_host,
@@ -1988,7 +2044,7 @@ static const struct cqhci_host_ops sdhci_msm_cqhci_ops = {
 	.enable		= sdhci_msm_cqe_enable,
 	.disable	= sdhci_msm_cqe_disable,
 #ifdef CONFIG_MMC_CRYPTO
-	.program_key	= sdhci_msm_program_key,
+	.uses_custom_crypto_profile = true,
 #endif
 };