scsi: ufs: Add program_key() variant op

On Snapdragon SoCs, the Linux kernel isn't permitted to directly access the
standard UFS crypto configuration registers.  Instead, programming and
evicting keys must be done through vendor-specific SMC calls.

To support this hardware, add a ->program_key() method to 'struct
ufs_hba_variant_ops'.  This allows overriding the UFS standard key
programming / eviction procedure.

Link: https://lore.kernel.org/r/20200710072013.177481-5-ebiggers@kernel.org
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 656c0691..b2ef18f 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -281,6 +281,7 @@ struct ufs_pwr_mode_info {
  * @dbg_register_dump: used to dump controller debug information
  * @phy_initialization: used to initialize phys
  * @device_reset: called to issue a reset pulse on the UFS device
+ * @program_key: program or evict an inline encryption key
  */
 struct ufs_hba_variant_ops {
 	const char *name;
@@ -314,6 +315,8 @@ struct ufs_hba_variant_ops {
 	void	(*config_scaling_param)(struct ufs_hba *hba,
 					struct devfreq_dev_profile *profile,
 					void *data);
+	int	(*program_key)(struct ufs_hba *hba,
+			       const union ufs_crypto_cfg_entry *cfg, int slot);
 };
 
 /* clock gating state  */