firmware: qcom_scm: update comment for ICE-related functions

The SCM calls QCOM_SCM_ES_INVALIDATE_ICE_KEY and
QCOM_SCM_ES_CONFIG_SET_ICE_KEY are also needed for eMMC inline
encryption support, not just for UFS.  Update the comments accordingly.
Reviewed-by: NSatya Tangirala <satyat@google.com>
Acked-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: NEric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20210125183810.198008-7-ebiggers@kernel.orgSigned-off-by: NUlf Hansson <ulf.hansson@linaro.org>

drivers/firmware/qcom_scm.c

@@ -965,8 +965,11 @@ EXPORT_SYMBOL(qcom_scm_ice_available);
  * qcom_scm_ice_invalidate_key() - Invalidate an inline encryption key
  * @index: the keyslot to invalidate
  *
- * The UFSHCI standard defines a standard way to do this, but it doesn't work on
- * these SoCs; only this SCM call does.
+ * The UFSHCI and eMMC standards define a standard way to do this, but it
+ * doesn't work on these SoCs; only this SCM call does.
+ *
+ * It is assumed that the SoC has only one ICE instance being used, as this SCM
+ * call doesn't specify which ICE instance the keyslot belongs to.
  *
  * Return: 0 on success; -errno on failure.
  */
@@ -995,10 +998,13 @@ EXPORT_SYMBOL(qcom_scm_ice_invalidate_key);
  *		    units, e.g. 1 = 512 bytes, 8 = 4096 bytes, etc.
  *
  * Program a key into a keyslot of Qualcomm ICE (Inline Crypto Engine), where it
- * can then be used to encrypt/decrypt UFS I/O requests inline.
+ * can then be used to encrypt/decrypt UFS or eMMC I/O requests inline.
+ *
+ * The UFSHCI and eMMC standards define a standard way to do this, but it
+ * doesn't work on these SoCs; only this SCM call does.
  *
- * The UFSHCI standard defines a standard way to do this, but it doesn't work on
- * these SoCs; only this SCM call does.
+ * It is assumed that the SoC has only one ICE instance being used, as this SCM
+ * call doesn't specify which ICE instance the keyslot belongs to.
  *
  * Return: 0 on success; -errno on failure.
  */