crypto: caam - generate hash keys in-place

When generating a split key or hashing the key, DMA mapping the key
buffers coming directly from user is incorrect, since they are
not guaranteed to be DMAable.

Update driver to first copy user-provided key in the output buffer
("key_out") and then use this buffer for in-place computation
(split key generation, respectively key hashing).

Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/caam/key_gen.c

@@ -48,7 +48,7 @@ int gen_split_key(struct device *jrdev, u8 *key_out,
 {
 	u32 *desc;
 	struct split_key_result result;
-	dma_addr_t dma_addr_in, dma_addr_out;
+	dma_addr_t dma_addr;
 	int ret = -ENOMEM;
 
 	adata->keylen = split_key_len(adata->algtype & OP_ALG_ALGSEL_MASK);
@@ -71,22 +71,17 @@ int gen_split_key(struct device *jrdev, u8 *key_out,
 		return ret;
 	}
 
-	dma_addr_in = dma_map_single(jrdev, (void *)key_in, keylen,
-				     DMA_TO_DEVICE);
-	if (dma_mapping_error(jrdev, dma_addr_in)) {
-		dev_err(jrdev, "unable to map key input memory\n");
+	memcpy(key_out, key_in, keylen);
+
+	dma_addr = dma_map_single(jrdev, key_out, adata->keylen_pad,
+				  DMA_BIDIRECTIONAL);
+	if (dma_mapping_error(jrdev, dma_addr)) {
+		dev_err(jrdev, "unable to map key memory\n");
 		goto out_free;
 	}
 
-	dma_addr_out = dma_map_single(jrdev, key_out, adata->keylen_pad,
-				      DMA_FROM_DEVICE);
-	if (dma_mapping_error(jrdev, dma_addr_out)) {
-		dev_err(jrdev, "unable to map key output memory\n");
-		goto out_unmap_in;
-	}
-
 	init_job_desc(desc, 0);
-	append_key(desc, dma_addr_in, keylen, CLASS_2 | KEY_DEST_CLASS_REG);
+	append_key(desc, dma_addr, keylen, CLASS_2 | KEY_DEST_CLASS_REG);
 
 	/* Sets MDHA up into an HMAC-INIT */
 	append_operation(desc, (adata->algtype & OP_ALG_ALGSEL_MASK) |
@@ -104,12 +99,10 @@ int gen_split_key(struct device *jrdev, u8 *key_out,
 	 * FIFO_STORE with the explicit split-key content store
 	 * (0x26 output type)
 	 */
-	append_fifo_store(desc, dma_addr_out, adata->keylen,
+	append_fifo_store(desc, dma_addr, adata->keylen,
 			  LDST_CLASS_2_CCB | FIFOST_TYPE_SPLIT_KEK);
 
 #ifdef DEBUG
-	print_hex_dump(KERN_ERR, "ctx.key@"__stringify(__LINE__)": ",
-		       DUMP_PREFIX_ADDRESS, 16, 4, key_in, keylen, 1);
 	print_hex_dump(KERN_ERR, "jobdesc@"__stringify(__LINE__)": ",
 		       DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc), 1);
 #endif
@@ -129,10 +122,7 @@ int gen_split_key(struct device *jrdev, u8 *key_out,
 #endif
 	}
 
-	dma_unmap_single(jrdev, dma_addr_out, adata->keylen_pad,
-			 DMA_FROM_DEVICE);
-out_unmap_in:
-	dma_unmap_single(jrdev, dma_addr_in, keylen, DMA_TO_DEVICE);
+	dma_unmap_single(jrdev, dma_addr, adata->keylen_pad, DMA_BIDIRECTIONAL);
 out_free:
 	kfree(desc);
 	return ret;