crypto: caam - improve key inlining

For authenc / stitched AEAD algorithms, check independently
each of the two (authentication, encryption) keys whether inlining
is possible.
Prioritize the inlining of the authentication key, since the length
of the (split) key is bigger than that of the encryption key.

For the other algorithms, compute only once per tfm the remaining
available bytes and decide whether key inlining is possible
based on this.
Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/caam/desc_constr.h

@@ -449,3 +449,42 @@ struct alginfo {
 	u64 key;
 	bool key_inline;
 };
+
+/**
+ * desc_inline_query() - Provide indications on which data items can be inlined
+ *                       and which shall be referenced in a shared descriptor.
+ * @sd_base_len: Shared descriptor base length - bytes consumed by the commands,
+ *               excluding the data items to be inlined (or corresponding
+ *               pointer if an item is not inlined). Each cnstr_* function that
+ *               generates descriptors should have a define mentioning
+ *               corresponding length.
+ * @jd_len: Maximum length of the job descriptor(s) that will be used
+ *          together with the shared descriptor.
+ * @data_len: Array of lengths of the data items trying to be inlined
+ * @inl_mask: 32bit mask with bit x = 1 if data item x can be inlined, 0
+ *            otherwise.
+ * @count: Number of data items (size of @data_len array); must be <= 32
+ *
+ * Return: 0 if data can be inlined / referenced, negative value if not. If 0,
+ *         check @inl_mask for details.
+ */
+static inline int desc_inline_query(unsigned int sd_base_len,
+				    unsigned int jd_len, unsigned int *data_len,
+				    u32 *inl_mask, unsigned int count)
+{
+	int rem_bytes = (int)(CAAM_DESC_BYTES_MAX - sd_base_len - jd_len);
+	unsigned int i;
+
+	*inl_mask = 0;
+	for (i = 0; (i < count) && (rem_bytes > 0); i++) {
+		if (rem_bytes - (int)(data_len[i] +
+			(count - i - 1) * CAAM_PTR_SZ) >= 0) {
+			rem_bytes -= data_len[i];
+			*inl_mask |= (1 << i);
+		} else {
+			rem_bytes -= CAAM_PTR_SZ;
+		}
+	}
+
+	return (rem_bytes >= 0) ? 0 : -1;
+}