[PATCH v2 06/10] crypto: tegra: Fix HASH intermediate result handling

[Akhil R <akhilrajeev@nvidia.com>]

The intermediate hash values generated during an update task were
handled incorrectly in the driver. The values have a defined format for
each algorithm. Copying and pasting from the HASH_RESULT register
balantly would not work for all the supported algorithms. This incorrect
handling causes failures when there is a context switch between multiple
operations.

To handle the expected format correctly, add a separate buffer for
storing the intermediate results for each request. Remove the previous
copy/paste functions which read/wrote to the registers directly. Instead
configure the hardware to get the intermediate result copied to the
buffer and use host1x path to restore the intermediate hash results.

Fixes: 0880bb3b00c8 ("crypto: tegra - Add Tegra Security Engine driver")
Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
---
 drivers/crypto/tegra/tegra-se-hash.c | 148 +++++++++++++++++----------
 drivers/crypto/tegra/tegra-se.h      |   1 +
 2 files changed, 97 insertions(+), 52 deletions(-)

diff --git a/drivers/crypto/tegra/tegra-se-hash.c b/drivers/crypto/tegra/tegra-se-hash.c
index 6da18f0f7ce9..89c1e1a0016b 100644
--- a/drivers/crypto/tegra/tegra-se-hash.c
+++ b/drivers/crypto/tegra/tegra-se-hash.c
@@ -34,6 +34,7 @@ struct tegra_sha_reqctx {
 	struct tegra_se_datbuf datbuf;
 	struct tegra_se_datbuf residue;
 	struct tegra_se_datbuf digest;
+	struct tegra_se_datbuf intr_res;
 	unsigned int alg;
 	unsigned int config;
 	unsigned int total_len;
@@ -211,9 +212,61 @@ static int tegra_sha_fallback_export(struct ahash_request *req, void *out)
 	return crypto_ahash_export(&rctx->fallback_req, out);
 }
 
-static int tegra_sha_prep_cmd(struct tegra_se *se, u32 *cpuvaddr,
+static int tegra_se_insert_hash_result(struct tegra_sha_ctx *ctx, u32 *cpuvaddr,
 			      struct tegra_sha_reqctx *rctx)
 {
+	u32 *res = (u32 *)rctx->intr_res.buf;
+	int i = 0, j;
+
+	cpuvaddr[i++] = 0;
+	cpuvaddr[i++] = host1x_opcode_setpayload(HASH_RESULT_REG_COUNT);
+	cpuvaddr[i++] = se_host1x_opcode_incr_w(SE_SHA_HASH_RESULT);
+
+	for (j = 0; j < HASH_RESULT_REG_COUNT; j++) {
+		int idx = j;
+
+		/*
+		 * The initial, intermediate and final hash value of SHA-384, SHA-512
+		 * in SHA_HASH_RESULT registers follow the below layout of bytes.
+		 *
+		 * +---------------+------------+
+		 * | HASH_RESULT_0 | B4...B7    |
+		 * +---------------+------------+
+		 * | HASH_RESULT_1 | B0...B3    |
+		 * +---------------+------------+
+		 * | HASH_RESULT_2 | B12...B15  |
+		 * +---------------+------------+
+		 * | HASH_RESULT_3 | B8...B11   |
+		 * +---------------+------------+
+		 * |            ......          |
+		 * +---------------+------------+
+		 * | HASH_RESULT_14| B60...B63  |
+		 * +---------------+------------+
+		 * | HASH_RESULT_15| B56...B59  |
+		 * +---------------+------------+
+		 *
+		 */
+		if (ctx->alg == SE_ALG_SHA384 || ctx->alg == SE_ALG_SHA512)
+			idx = (j % 2) ? j - 1 : j + 1;
+
+		/* For SHA-1, SHA-224, SHA-256, SHA-384, SHA-512 the initial
+		 * intermediate and final hash value when stored in
+		 * SHA_HASH_RESULT registers, the byte order is NOT in
+		 * little-endian.
+		 */
+		if (ctx->alg <= SE_ALG_SHA512)
+			cpuvaddr[i++] = be32_to_cpu(res[idx]);
+		else
+			cpuvaddr[i++] = res[idx];
+	}
+
+	return i;
+}
+
+static int tegra_sha_prep_cmd(struct tegra_sha_ctx *ctx, u32 *cpuvaddr,
+			      struct tegra_sha_reqctx *rctx)
+{
+	struct tegra_se *se = ctx->se;
 	u64 msg_len, msg_left;
 	int i = 0;
 
@@ -241,7 +294,7 @@ static int tegra_sha_prep_cmd(struct tegra_se *se, u32 *cpuvaddr,
 	cpuvaddr[i++] = upper_32_bits(msg_left);
 	cpuvaddr[i++] = 0;
 	cpuvaddr[i++] = 0;
-	cpuvaddr[i++] = host1x_opcode_setpayload(6);
+	cpuvaddr[i++] = host1x_opcode_setpayload(2);
 	cpuvaddr[i++] = se_host1x_opcode_incr_w(SE_SHA_CFG);
 	cpuvaddr[i++] = rctx->config;
 
@@ -249,15 +302,29 @@ static int tegra_sha_prep_cmd(struct tegra_se *se, u32 *cpuvaddr,
 		cpuvaddr[i++] = SE_SHA_TASK_HASH_INIT;
 		rctx->task &= ~SHA_FIRST;
 	} else {
-		cpuvaddr[i++] = 0;
+		/*
+		 * If it isn't the first task, program the HASH_RESULT register
+		 * with the intermediate result from the previous task
+		 */
+		i += tegra_se_insert_hash_result(ctx, cpuvaddr + i, rctx);
 	}
 
+	cpuvaddr[i++] = host1x_opcode_setpayload(4);
+	cpuvaddr[i++] = se_host1x_opcode_incr_w(SE_SHA_IN_ADDR);
 	cpuvaddr[i++] = rctx->datbuf.addr;
 	cpuvaddr[i++] = (u32)(SE_ADDR_HI_MSB(upper_32_bits(rctx->datbuf.addr)) |
 				SE_ADDR_HI_SZ(rctx->datbuf.size));
-	cpuvaddr[i++] = rctx->digest.addr;
-	cpuvaddr[i++] = (u32)(SE_ADDR_HI_MSB(upper_32_bits(rctx->digest.addr)) |
-				SE_ADDR_HI_SZ(rctx->digest.size));
+
+	if (rctx->task & SHA_UPDATE) {
+		cpuvaddr[i++] = rctx->intr_res.addr;
+		cpuvaddr[i++] = (u32)(SE_ADDR_HI_MSB(upper_32_bits(rctx->intr_res.addr)) |
+					SE_ADDR_HI_SZ(rctx->intr_res.size));
+	} else {
+		cpuvaddr[i++] = rctx->digest.addr;
+		cpuvaddr[i++] = (u32)(SE_ADDR_HI_MSB(upper_32_bits(rctx->digest.addr)) |
+					SE_ADDR_HI_SZ(rctx->digest.size));
+	}
+
 	if (rctx->key_id) {
 		cpuvaddr[i++] = host1x_opcode_setpayload(1);
 		cpuvaddr[i++] = se_host1x_opcode_nonincr_w(SE_SHA_CRYPTO_CFG);
@@ -266,36 +333,18 @@ static int tegra_sha_prep_cmd(struct tegra_se *se, u32 *cpuvaddr,
 
 	cpuvaddr[i++] = host1x_opcode_setpayload(1);
 	cpuvaddr[i++] = se_host1x_opcode_nonincr_w(SE_SHA_OPERATION);
-	cpuvaddr[i++] = SE_SHA_OP_WRSTALL |
-			SE_SHA_OP_START |
+	cpuvaddr[i++] = SE_SHA_OP_WRSTALL | SE_SHA_OP_START |
 			SE_SHA_OP_LASTBUF;
 	cpuvaddr[i++] = se_host1x_opcode_nonincr(host1x_uclass_incr_syncpt_r(), 1);
 	cpuvaddr[i++] = host1x_uclass_incr_syncpt_cond_f(1) |
 			host1x_uclass_incr_syncpt_indx_f(se->syncpt_id);
 
-	dev_dbg(se->dev, "msg len %llu msg left %llu cfg %#x",
-		msg_len, msg_left, rctx->config);
+	dev_dbg(se->dev, "msg len %llu msg left %llu sz %lu cfg %#x",
+		msg_len, msg_left, rctx->datbuf.size, rctx->config);
 
 	return i;
 }
 
-static void tegra_sha_copy_hash_result(struct tegra_se *se, struct tegra_sha_reqctx *rctx)
-{
-	int i;
-
-	for (i = 0; i < HASH_RESULT_REG_COUNT; i++)
-		rctx->result[i] = readl(se->base + se->hw->regs->result + (i * 4));
-}
-
-static void tegra_sha_paste_hash_result(struct tegra_se *se, struct tegra_sha_reqctx *rctx)
-{
-	int i;
-
-	for (i = 0; i < HASH_RESULT_REG_COUNT; i++)
-		writel(rctx->result[i],
-		       se->base + se->hw->regs->result + (i * 4));
-}
-
 static int tegra_sha_do_init(struct ahash_request *req)
 {
 	struct tegra_sha_reqctx *rctx = ahash_request_ctx(req);
@@ -325,8 +374,17 @@ static int tegra_sha_do_init(struct ahash_request *req)
 	if (!rctx->residue.buf)
 		goto resbuf_fail;
 
+	rctx->intr_res.size = HASH_RESULT_REG_COUNT * 4;
+	rctx->intr_res.buf = dma_alloc_coherent(se->dev, rctx->intr_res.size,
+						&rctx->intr_res.addr, GFP_KERNEL);
+	if (!rctx->intr_res.buf)
+		goto intr_res_fail;
+
 	return 0;
 
+intr_res_fail:
+	dma_free_coherent(se->dev, rctx->residue.size, rctx->residue.buf,
+			  rctx->residue.addr);
 resbuf_fail:
 	dma_free_coherent(se->dev, rctx->digest.size, rctx->digest.buf,
 			  rctx->digest.addr);
@@ -356,7 +414,6 @@ static int tegra_sha_do_update(struct ahash_request *req)
 
 	rctx->src_sg = req->src;
 	rctx->datbuf.size = (req->nbytes + rctx->residue.size) - nresidue;
-	rctx->total_len += rctx->datbuf.size;
 
 	/*
 	 * If nbytes are less than a block size, copy it residue and
@@ -365,12 +422,12 @@ static int tegra_sha_do_update(struct ahash_request *req)
 	if (nblks < 1) {
 		scatterwalk_map_and_copy(rctx->residue.buf + rctx->residue.size,
 					 rctx->src_sg, 0, req->nbytes, 0);
-
 		rctx->residue.size += req->nbytes;
+
 		return 0;
 	}
 
-	rctx->datbuf.buf = dma_alloc_coherent(ctx->se->dev, rctx->datbuf.size,
+	rctx->datbuf.buf = dma_alloc_coherent(se->dev, rctx->datbuf.size,
 					      &rctx->datbuf.addr, GFP_KERNEL);
 	if (!rctx->datbuf.buf)
 		return -ENOMEM;
@@ -387,31 +444,15 @@ static int tegra_sha_do_update(struct ahash_request *req)
 
 	/* Update residue value with the residue after current block */
 	rctx->residue.size = nresidue;
+	rctx->total_len += rctx->datbuf.size;
 
 	rctx->config = tegra_sha_get_config(rctx->alg) |
-			SE_SHA_DST_HASH_REG;
-
-	/*
-	 * If this is not the first 'update' call, paste the previous copied
-	 * intermediate results to the registers so that it gets picked up.
-	 * This is to support the import/export functionality.
-	 */
-	if (!(rctx->task & SHA_FIRST))
-		tegra_sha_paste_hash_result(se, rctx);
-
-	size = tegra_sha_prep_cmd(se, cpuvaddr, rctx);
+			SE_SHA_DST_MEMORY;
 
+	size = tegra_sha_prep_cmd(ctx, cpuvaddr, rctx);
 	ret = tegra_se_host1x_submit(se, se->cmdbuf, size);
 
-	/*
-	 * If this is not the final update, copy the intermediate results
-	 * from the registers so that it can be used in the next 'update'
-	 * call. This is to support the import/export functionality.
-	 */
-	if (!(rctx->task & SHA_FINAL))
-		tegra_sha_copy_hash_result(se, rctx);
-
-	dma_free_coherent(ctx->se->dev, rctx->datbuf.size,
+	dma_free_coherent(se->dev, rctx->datbuf.size,
 			  rctx->datbuf.buf, rctx->datbuf.addr);
 
 	return ret;
@@ -443,8 +484,7 @@ static int tegra_sha_do_final(struct ahash_request *req)
 	rctx->config = tegra_sha_get_config(rctx->alg) |
 		       SE_SHA_DST_MEMORY;
 
-	size = tegra_sha_prep_cmd(se, cpuvaddr, rctx);
-
+	size = tegra_sha_prep_cmd(ctx, cpuvaddr, rctx);
 	ret = tegra_se_host1x_submit(se, se->cmdbuf, size);
 	if (ret)
 		goto out;
@@ -461,6 +501,10 @@ static int tegra_sha_do_final(struct ahash_request *req)
 			  rctx->residue.buf, rctx->residue.addr);
 	dma_free_coherent(se->dev, rctx->digest.size, rctx->digest.buf,
 			  rctx->digest.addr);
+
+	dma_free_coherent(se->dev, rctx->intr_res.size, rctx->intr_res.buf,
+			  rctx->intr_res.addr);
+
 	return ret;
 }
 
diff --git a/drivers/crypto/tegra/tegra-se.h b/drivers/crypto/tegra/tegra-se.h
index e1ec37bfb80a..0f5bcf27358b 100644
--- a/drivers/crypto/tegra/tegra-se.h
+++ b/drivers/crypto/tegra/tegra-se.h
@@ -24,6 +24,7 @@
 #define SE_STREAM_ID					0x90
 
 #define SE_SHA_CFG					0x4004
+#define SE_SHA_IN_ADDR					0x400c
 #define SE_SHA_KEY_ADDR					0x4094
 #define SE_SHA_KEY_DATA					0x4098
 #define SE_SHA_KEYMANIFEST				0x409c
-- 
2.43.2