[PATCHv2,2/5] block/sed: Add helper to qualify response tokens

Commit Message

Jon Derrick Feb. 18, 2017, midnight UTC

Add helper which verifies the response token is valid and matches the
expected value. Merges token_type and response_get_token.

Signed-off-by: Jon Derrick <[e-mail]>
---
 block/sed-opal.c | 61 +++++++++++++++++++++++---------------------------------
 1 file changed, 25 insertions(+), 36 deletions(-)

Patch

diff --git a/block/sed-opal.c b/block/sed-opal.c
index 4675fd8..d3d6db2 100644
--- a/block/sed-opal.c
+++ b/block/sed-opal.c
@@ -662,48 +662,25 @@  static int cmd_finalize(struct opal_dev *cmd, u32 hsn, u32 tsn)
 	return 0;
 }
 
-static enum opal_response_token token_type(const struct parsed_resp *resp,
-					   int n)
+static const struct opal_resp_tok *response_get_token(
+				const struct parsed_resp *resp,
+				int n)
 {
 	const struct opal_resp_tok *tok;
 
 	if (n >= resp->num) {
 		pr_err("Token number doesn't exist: %d, resp: %d\n",
 		       n, resp->num);
-		return OPAL_DTA_TOKENID_INVALID;
+		return ERR_PTR(-EINVAL);
 	}
 
 	tok = &resp->toks[n];
 	if (tok->len == 0) {
 		pr_err("Token length must be non-zero\n");
-		return OPAL_DTA_TOKENID_INVALID;
+		return ERR_PTR(-EINVAL);
 	}
 
-	return tok->type;
-}
-
-/*
- * This function returns 0 in case of invalid token. One should call
- * token_type() first to find out if the token is valid or not.
- */
-static enum opal_token response_get_token(const struct parsed_resp *resp,
-					  int n)
-{
-	const struct opal_resp_tok *tok;
-
-	if (n >= resp->num) {
-		pr_err("Token number doesn't exist: %d, resp: %d\n",
-		       n, resp->num);
-		return 0;
-	}
-
-	tok = &resp->toks[n];
-	if (tok->len == 0) {
-		pr_err("Token length must be non-zero\n");
-		return 0;
-	}
-
-	return tok->pos[0];
+	return tok;
 }
 
 static ssize_t response_parse_tiny(struct opal_resp_tok *tok,
@@ -922,20 +899,32 @@  static u64 response_get_u64(const struct parsed_resp *resp, int n)
 	return resp->toks[n].stored.u;
 }
 
+static bool response_token_matches(const struct opal_resp_tok *token, u8 match)
+{
+	if (IS_ERR(token) ||
+	    token->type != OPAL_DTA_TOKENID_TOKEN ||
+	    token->pos[0] != match)
+		return false;
+	return true;
+}
+
 static u8 response_status(const struct parsed_resp *resp)
 {
-	if (token_type(resp, 0) == OPAL_DTA_TOKENID_TOKEN &&
-	    response_get_token(resp, 0) == OPAL_ENDOFSESSION) {
+	const struct opal_resp_tok *tok;
+
+	tok = response_get_token(resp, 0);
+	if (response_token_matches(tok, OPAL_ENDOFSESSION))
 		return 0;
-	}
 
 	if (resp->num < 5)
 		return DTAERROR_NO_METHOD_STATUS;
 
-	if (token_type(resp, resp->num - 1) != OPAL_DTA_TOKENID_TOKEN ||
-	    token_type(resp, resp->num - 5) != OPAL_DTA_TOKENID_TOKEN ||
-	    response_get_token(resp, resp->num - 1) != OPAL_ENDLIST ||
-	    response_get_token(resp, resp->num - 5) != OPAL_STARTLIST)
+	tok = response_get_token(resp, resp->num - 5);
+	if (!response_token_matches(tok, OPAL_STARTLIST))
+		return DTAERROR_NO_METHOD_STATUS;
+
+	tok = response_get_token(resp, resp->num - 1);
+	if (!response_token_matches(tok, OPAL_ENDLIST))
 		return DTAERROR_NO_METHOD_STATUS;
 
 	return response_get_u64(resp, resp->num - 4);