scsi: ufs: core: Add fill_crypto_prdt variant op

Add a variant op to allow host drivers to initialize nonstandard
crypto-related fields in the PRDT.  This is needed to support inline
encryption on the "Exynos" UFS controller.

Note that this will be used together with the support for overriding the
PRDT entry size that was already added by commit ada1e65 ("scsi: ufs:
core: Allow UFS host drivers to override the sg entry size").

Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20240708235330.103590-5-ebiggers@kernel.org
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/ufs/core/ufshcd-crypto.h

@@ -37,6 +37,19 @@ ufshcd_prepare_req_desc_hdr_crypto(struct ufshcd_lrb *lrbp,
 	h->dunu = cpu_to_le32(upper_32_bits(lrbp->data_unit_num));
 }
 
+static inline int ufshcd_crypto_fill_prdt(struct ufs_hba *hba,
+					  struct ufshcd_lrb *lrbp)
+{
+	struct scsi_cmnd *cmd = lrbp->cmd;
+	const struct bio_crypt_ctx *crypt_ctx = scsi_cmd_to_rq(cmd)->crypt_ctx;
+
+	if (crypt_ctx && hba->vops && hba->vops->fill_crypto_prdt)
+		return hba->vops->fill_crypto_prdt(hba, crypt_ctx,
+						   lrbp->ucd_prdt_ptr,
+						   scsi_sg_count(cmd));
+	return 0;
+}
+
 bool ufshcd_crypto_enable(struct ufs_hba *hba);
 
 int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba);
@@ -54,6 +67,12 @@ static inline void
 ufshcd_prepare_req_desc_hdr_crypto(struct ufshcd_lrb *lrbp,
 				   struct request_desc_header *h) { }
 
+static inline int ufshcd_crypto_fill_prdt(struct ufs_hba *hba,
+					  struct ufshcd_lrb *lrbp)
+{
+	return 0;
+}
+
 static inline bool ufshcd_crypto_enable(struct ufs_hba *hba)
 {
 	return false;

drivers/ufs/core/ufshcd.c

@@ -2641,7 +2641,7 @@ static int ufshcd_map_sg(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 
 	ufshcd_sgl_to_prdt(hba, lrbp, sg_segments, scsi_sglist(cmd));
 
-	return 0;
+	return ufshcd_crypto_fill_prdt(hba, lrbp);
 }
 
 /**

include/ufs/ufshcd.h

@@ -322,6 +322,7 @@ struct ufs_pwr_mode_info {
  * @device_reset: called to issue a reset pulse on the UFS device
  * @config_scaling_param: called to configure clock scaling parameters
  * @program_key: program or evict an inline encryption key
+ * @fill_crypto_prdt: initialize crypto-related fields in the PRDT
  * @event_notify: called to notify important events
  * @reinit_notify: called to notify reinit of UFSHCD during max gear switch
  * @mcq_config_resource: called to configure MCQ platform resources
@@ -367,6 +368,9 @@ struct ufs_hba_variant_ops {
 				struct devfreq_simple_ondemand_data *data);
 	int	(*program_key)(struct ufs_hba *hba,
 			       const union ufs_crypto_cfg_entry *cfg, int slot);
+	int	(*fill_crypto_prdt)(struct ufs_hba *hba,
+				    const struct bio_crypt_ctx *crypt_ctx,
+				    void *prdt, unsigned int num_segments);
 	void	(*event_notify)(struct ufs_hba *hba,
 				enum ufs_event_type evt, void *data);
 	void	(*reinit_notify)(struct ufs_hba *);