[PATCH 5/6] crypto: eip93: order result descriptor reads after PE_READY

[Jihong Min <hurryman2212@gmail.com>]

The result handler polls ownership bits until the packet engine reports the
descriptor as ready. Ensure later descriptor reads observe the DMA writes
that completed before PE_READY became visible.

Use the value already read from the descriptor for error parsing.

Fixes: 9739f5f93b78 ("crypto: eip93 - Add Inside Secure SafeXcel EIP-93 crypto engine support")
Reported-by: Benjamin Larsson <benjamin.larsson@genexis.eu>
Suggested-by: Benjamin Larsson <benjamin.larsson@genexis.eu>
Assisted-by: Codex:gpt-5.5
Signed-off-by: Jihong Min <hurryman2212@gmail.com>
---
 drivers/crypto/inside-secure/eip93/eip93-main.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/crypto/inside-secure/eip93/eip93-main.c b/drivers/crypto/inside-secure/eip93/eip93-main.c
index 276839e1a515..e3bd28cc0c67 100644
--- a/drivers/crypto/inside-secure/eip93/eip93-main.c
+++ b/drivers/crypto/inside-secure/eip93/eip93-main.c
@@ -224,11 +224,14 @@ static void eip93_handle_result_descriptor(struct eip93_device *eip93)
 			 FIELD_GET(EIP93_PE_LENGTH_HOST_PE_READY, pe_length) !=
 			 EIP93_PE_LENGTH_PE_READY);
 
-		err = rdesc->pe_ctrl_stat_word & (EIP93_PE_CTRL_PE_EXT_ERR_CODE |
-						  EIP93_PE_CTRL_PE_EXT_ERR |
-						  EIP93_PE_CTRL_PE_SEQNUM_ERR |
-						  EIP93_PE_CTRL_PE_PAD_ERR |
-						  EIP93_PE_CTRL_PE_AUTH_ERR);
+		/* Order descriptor reads after device ownership is returned. */
+		dma_rmb();
+
+		err = pe_ctrl_stat & (EIP93_PE_CTRL_PE_EXT_ERR_CODE |
+				      EIP93_PE_CTRL_PE_EXT_ERR |
+				      EIP93_PE_CTRL_PE_SEQNUM_ERR |
+				      EIP93_PE_CTRL_PE_PAD_ERR |
+				      EIP93_PE_CTRL_PE_AUTH_ERR);
 
 		desc_flags = FIELD_GET(EIP93_PE_USER_ID_DESC_FLAGS, rdesc->user_id);
 		crypto_idr = FIELD_GET(EIP93_PE_USER_ID_CRYPTO_IDR, rdesc->user_id);
-- 
2.53.0