crypto: sun8i-ss - Remove GFP_DMA and add DMA alignment padding

GFP_DMA does not guarantee that the returned memory is aligned
for DMA.  In fact for sun8i-ss it is superfluous and can be removed.

However, kmalloc may start returning DMA-unaligned memory in future
so fix this by adding the alignment by hand.

Signed-off-by: Herbert Xu <[email protected]>
Tested-by: Corentin Labbe <[email protected]>
Acked-by: Corentin Labbe <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>

Author: herbertx

drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c

@@ -452,7 +452,7 @@ int sun8i_ss_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
 	}
 	kfree_sensitive(op->key);
 	op->keylen = keylen;
-	op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
+	op->key = kmemdup(key, keylen, GFP_KERNEL);
 	if (!op->key)
 		return -ENOMEM;
 
@@ -475,7 +475,7 @@ int sun8i_ss_des3_setkey(struct crypto_skcipher *tfm, const u8 *key,
 
 	kfree_sensitive(op->key);
 	op->keylen = keylen;
-	op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
+	op->key = kmemdup(key, keylen, GFP_KERNEL);
 	if (!op->key)
 		return -ENOMEM;
 

drivers/crypto/allwinner/sun8i-ss/sun8i-ss-core.c

@@ -16,6 +16,7 @@
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/irq.h>
+#include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
@@ -527,15 +528,15 @@ static int allocate_flows(struct sun8i_ss_dev *ss)
 		init_completion(&ss->flows[i].complete);
 
 		ss->flows[i].biv = devm_kmalloc(ss->dev, AES_BLOCK_SIZE,
-						GFP_KERNEL | GFP_DMA);
+						GFP_KERNEL);
 		if (!ss->flows[i].biv) {
 			err = -ENOMEM;
 			goto error_engine;
 		}
 
 		for (j = 0; j < MAX_SG; j++) {
 			ss->flows[i].iv[j] = devm_kmalloc(ss->dev, AES_BLOCK_SIZE,
-							  GFP_KERNEL | GFP_DMA);
+							  GFP_KERNEL);
 			if (!ss->flows[i].iv[j]) {
 				err = -ENOMEM;
 				goto error_engine;
@@ -544,13 +545,15 @@ static int allocate_flows(struct sun8i_ss_dev *ss)
 
 		/* the padding could be up to two block. */
 		ss->flows[i].pad = devm_kmalloc(ss->dev, MAX_PAD_SIZE,
-						GFP_KERNEL | GFP_DMA);
+						GFP_KERNEL);
 		if (!ss->flows[i].pad) {
 			err = -ENOMEM;
 			goto error_engine;
 		}
-		ss->flows[i].result = devm_kmalloc(ss->dev, SHA256_DIGEST_SIZE,
-						   GFP_KERNEL | GFP_DMA);
+		ss->flows[i].result =
+			devm_kmalloc(ss->dev, max(SHA256_DIGEST_SIZE,
+						  dma_get_cache_alignment()),
+				     GFP_KERNEL);
 		if (!ss->flows[i].result) {
 			err = -ENOMEM;
 			goto error_engine;

drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c

@@ -79,10 +79,10 @@ int sun8i_ss_hmac_setkey(struct crypto_ahash *ahash, const u8 *key,
 		memcpy(tfmctx->key, key, keylen);
 	}
 
-	tfmctx->ipad = kzalloc(bs, GFP_KERNEL | GFP_DMA);
+	tfmctx->ipad = kzalloc(bs, GFP_KERNEL);
 	if (!tfmctx->ipad)
 		return -ENOMEM;
-	tfmctx->opad = kzalloc(bs, GFP_KERNEL | GFP_DMA);
+	tfmctx->opad = kzalloc(bs, GFP_KERNEL);
 	if (!tfmctx->opad) {
 		ret = -ENOMEM;
 		goto err_opad;

drivers/crypto/allwinner/sun8i-ss/sun8i-ss-prng.c

@@ -11,6 +11,8 @@
  */
 #include "sun8i-ss.h"
 #include <linux/dma-mapping.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
 #include <linux/pm_runtime.h>
 #include <crypto/internal/rng.h>
 
@@ -25,7 +27,7 @@ int sun8i_ss_prng_seed(struct crypto_rng *tfm, const u8 *seed,
 		ctx->seed = NULL;
 	}
 	if (!ctx->seed)
-		ctx->seed = kmalloc(slen, GFP_KERNEL | GFP_DMA);
+		ctx->seed = kmalloc(slen, GFP_KERNEL);
 	if (!ctx->seed)
 		return -ENOMEM;
 
@@ -58,6 +60,7 @@ int sun8i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,
 	struct sun8i_ss_rng_tfm_ctx *ctx = crypto_rng_ctx(tfm);
 	struct rng_alg *alg = crypto_rng_alg(tfm);
 	struct sun8i_ss_alg_template *algt;
+	unsigned int todo_with_padding;
 	struct sun8i_ss_dev *ss;
 	dma_addr_t dma_iv, dma_dst;
 	unsigned int todo;
@@ -81,7 +84,11 @@ int sun8i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,
 	todo = dlen + PRNG_SEED_SIZE + PRNG_DATA_SIZE;
 	todo -= todo % PRNG_DATA_SIZE;
 
-	d = kzalloc(todo, GFP_KERNEL | GFP_DMA);
+	todo_with_padding = ALIGN(todo, dma_get_cache_alignment());
+	if (todo_with_padding < todo || todo < dlen)
+		return -EOVERFLOW;
+
+	d = kzalloc(todo_with_padding, GFP_KERNEL);
 	if (!d)
 		return -ENOMEM;