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From:   Tzung-Bi Shih <tzungbi@kernel.org>
To:     bleung@chromium.org, groeck@chromium.org
Cc:     chrome-platform@lists.linux.dev, tzungbi@kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH 07/13] platform/chrome: cros_ec_proto: separate fill_protocol_info()
Date:   Mon,  6 Jun 2022 14:10:45 +0000
Message-Id: <20220606141051.285823-8-tzungbi@kernel.org>
In-Reply-To: <20220606141051.285823-1-tzungbi@kernel.org>
References: <20220606141051.285823-1-tzungbi@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Rename cros_ec_host_command_proto_query() to fill_protocol_info() and
make it responsible for setting `ec_dev` fields according to the
response protocol info.

Also make cros_ec_get_host_event_wake_mask() allocate its own message
buffer.  It was lucky that size of `struct ec_response_host_event_mask`
is less than `struct ec_response_get_protocol_info`.  Thus, the buffer
wasn't overflow.

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
---
 drivers/platform/chrome/cros_ec_proto.c      | 130 +++++++++----------
 drivers/platform/chrome/cros_ec_proto_test.c |  28 ++--
 2 files changed, 76 insertions(+), 82 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index 71ba6a56ad7c..f57b4dba95b7 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -242,47 +242,53 @@ EXPORT_SYMBOL(cros_ec_check_result);
  * the caller has ec_dev->lock mutex, or the caller knows there is
  * no other command in progress.
  */
-static int cros_ec_get_host_event_wake_mask(struct cros_ec_device *ec_dev,
-					    struct cros_ec_command *msg,
-					    uint32_t *mask)
+static int cros_ec_get_host_event_wake_mask(struct cros_ec_device *ec_dev, uint32_t *mask)
 {
+	struct cros_ec_command *msg;
 	struct ec_response_host_event_mask *r;
 	int ret, mapped;
 
+	msg = kzalloc(sizeof(*msg) + sizeof(*r), GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
 	msg->command = EC_CMD_HOST_EVENT_GET_WAKE_MASK;
-	msg->version = 0;
-	msg->outsize = 0;
 	msg->insize = sizeof(*r);
 
 	ret = send_command(ec_dev, msg);
 	if (ret >= 0) {
 		mapped = cros_ec_map_error(msg->result);
-		if (mapped)
-			return mapped;
+		if (mapped) {
+			ret = mapped;
+			goto exit;
+		}
 	}
 	if (ret > 0) {
 		r = (struct ec_response_host_event_mask *)msg->data;
 		*mask = r->mask;
 	}
 
+exit:
+	kfree(msg);
 	return ret;
 }
 
-static int cros_ec_host_command_proto_query(struct cros_ec_device *ec_dev,
-					    int devidx,
-					    struct cros_ec_command *msg)
+static int fill_protocol_info(struct cros_ec_device *ec_dev, int devidx)
 {
-	/*
-	 * Try using v3+ to query for supported protocols. If this
-	 * command fails, fall back to v2. Returns the highest protocol
-	 * supported by the EC.
-	 * Also sets the max request/response/passthru size.
-	 */
+	struct cros_ec_command *msg;
+	struct ec_response_get_protocol_info *info;
 	int ret;
 
-	memset(msg, 0, sizeof(*msg));
+	ec_dev->proto_version = 3;
+	if (devidx > 0)
+		ec_dev->max_passthru = 0;
+
+	msg = kzalloc(sizeof(*msg) + sizeof(*info), GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
 	msg->command = EC_CMD_PASSTHRU_OFFSET(devidx) | EC_CMD_GET_PROTOCOL_INFO;
-	msg->insize = sizeof(struct ec_response_get_protocol_info);
+	msg->insize = sizeof(*info);
 
 	ret = send_command(ec_dev, msg);
 	/*
@@ -299,15 +305,43 @@ static int cros_ec_host_command_proto_query(struct cros_ec_device *ec_dev,
 		dev_dbg(ec_dev->dev,
 			"failed to check for EC[%d] protocol version: %d\n",
 			devidx, ret);
-		return ret;
+		goto exit;
 	}
 
-	if (devidx > 0 && msg->result == EC_RES_INVALID_COMMAND)
-		return -ENODEV;
-	else if (msg->result != EC_RES_SUCCESS)
-		return msg->result;
+	ret = cros_ec_map_error(msg->result);
+	if (ret)
+		goto exit;
+
+	info = (struct ec_response_get_protocol_info *)msg->data;
+
+	switch (devidx) {
+	case CROS_EC_DEV_EC_INDEX:
+		ec_dev->max_request = info->max_request_packet_size -
+						sizeof(struct ec_host_request);
+		ec_dev->max_response = info->max_response_packet_size -
+						sizeof(struct ec_host_response);
+		ec_dev->proto_version = min(EC_HOST_REQUEST_VERSION,
+					    fls(info->protocol_versions) - 1);
+		ec_dev->din_size = info->max_response_packet_size + EC_MAX_RESPONSE_OVERHEAD;
+		ec_dev->dout_size = info->max_request_packet_size + EC_MAX_REQUEST_OVERHEAD;
+
+		dev_dbg(ec_dev->dev, "using proto v%u\n", ec_dev->proto_version);
+		break;
+	case CROS_EC_DEV_PD_INDEX:
+		ec_dev->max_passthru = info->max_request_packet_size -
+						sizeof(struct ec_host_request);
+
+		dev_dbg(ec_dev->dev, "found PD chip\n");
+		break;
+	default:
+		dev_dbg(ec_dev->dev, "unknwon passthru index: %d\n", devidx);
+		break;
+	}
 
-	return 0;
+	ret = 0;
+exit:
+	kfree(msg);
+	return ret;
 }
 
 static int cros_ec_host_command_proto_query_v2(struct cros_ec_device *ec_dev)
@@ -417,51 +451,13 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
 int cros_ec_query_all(struct cros_ec_device *ec_dev)
 {
 	struct device *dev = ec_dev->dev;
-	struct cros_ec_command *proto_msg;
-	struct ec_response_get_protocol_info *proto_info;
 	u32 ver_mask = 0;
 	int ret;
 
-	proto_msg = kzalloc(sizeof(*proto_msg) + sizeof(*proto_info),
-			    GFP_KERNEL);
-	if (!proto_msg)
-		return -ENOMEM;
-
 	/* First try sending with proto v3. */
-	ec_dev->proto_version = 3;
-	ret = cros_ec_host_command_proto_query(ec_dev, CROS_EC_DEV_EC_INDEX, proto_msg);
-
-	if (ret == 0) {
-		proto_info = (struct ec_response_get_protocol_info *)
-			proto_msg->data;
-		ec_dev->max_request = proto_info->max_request_packet_size -
-			sizeof(struct ec_host_request);
-		ec_dev->max_response = proto_info->max_response_packet_size -
-			sizeof(struct ec_host_response);
-		ec_dev->proto_version =
-			min(EC_HOST_REQUEST_VERSION,
-					fls(proto_info->protocol_versions) - 1);
-		dev_dbg(ec_dev->dev,
-			"using proto v%u\n",
-			ec_dev->proto_version);
-
-		ec_dev->din_size = proto_info->max_response_packet_size + EC_MAX_RESPONSE_OVERHEAD;
-		ec_dev->dout_size = proto_info->max_request_packet_size + EC_MAX_REQUEST_OVERHEAD;
-
-		/*
-		 * Check for PD
-		 */
-		ret = cros_ec_host_command_proto_query(ec_dev, CROS_EC_DEV_PD_INDEX, proto_msg);
-
-		if (ret) {
-			dev_dbg(ec_dev->dev, "no PD chip found: %d\n", ret);
-			ec_dev->max_passthru = 0;
-		} else {
-			dev_dbg(ec_dev->dev, "found PD chip\n");
-			ec_dev->max_passthru =
-				proto_info->max_request_packet_size -
-				sizeof(struct ec_host_request);
-		}
+	if (!fill_protocol_info(ec_dev, CROS_EC_DEV_EC_INDEX)) {
+		/* Check for PD. */
+		fill_protocol_info(ec_dev, CROS_EC_DEV_PD_INDEX);
 	} else {
 		/* Try querying with a v2 hello message. */
 		ec_dev->proto_version = 2;
@@ -524,8 +520,7 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
 	ec_dev->host_sleep_v1 = (ret >= 0 && (ver_mask & EC_VER_MASK(1)));
 
 	/* Get host event wake mask. */
-	ret = cros_ec_get_host_event_wake_mask(ec_dev, proto_msg,
-					       &ec_dev->host_event_wake_mask);
+	ret = cros_ec_get_host_event_wake_mask(ec_dev, &ec_dev->host_event_wake_mask);
 	if (ret < 0) {
 		/*
 		 * If the EC doesn't support EC_CMD_HOST_EVENT_GET_WAKE_MASK,
@@ -556,7 +551,6 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
 	ret = 0;
 
 exit:
-	kfree(proto_msg);
 	return ret;
 }
 EXPORT_SYMBOL(cros_ec_query_all);
diff --git a/drivers/platform/chrome/cros_ec_proto_test.c b/drivers/platform/chrome/cros_ec_proto_test.c
index 5169bf33360b..cdedbdfc1885 100644
--- a/drivers/platform/chrome/cros_ec_proto_test.c
+++ b/drivers/platform/chrome/cros_ec_proto_test.c
@@ -194,7 +194,7 @@ static void cros_ec_proto_test_query_all_normal(struct kunit *test)
 	struct ec_xfer_mock *mock;
 	int ret;
 
-	/* For cros_ec_host_command_proto_query() without passthru. */
+	/* For fill_protocol_info() without passthru. */
 	{
 		struct ec_response_get_protocol_info *data;
 
@@ -207,7 +207,7 @@ static void cros_ec_proto_test_query_all_normal(struct kunit *test)
 		data->max_response_packet_size = 0xef;
 	}
 
-	/* For cros_ec_host_command_proto_query() with passthru. */
+	/* For fill_protocol_info() with passthru. */
 	{
 		struct ec_response_get_protocol_info *data;
 
@@ -255,7 +255,7 @@ static void cros_ec_proto_test_query_all_normal(struct kunit *test)
 	ret = cros_ec_query_all(ec_dev);
 	KUNIT_EXPECT_EQ(test, ret, 0);
 
-	/* For cros_ec_host_command_proto_query() without passthru. */
+	/* For fill_protocol_info() without passthru. */
 	{
 		mock = cros_kunit_ec_xfer_mock_next();
 		KUNIT_EXPECT_PTR_NE(test, mock, NULL);
@@ -273,7 +273,7 @@ static void cros_ec_proto_test_query_all_normal(struct kunit *test)
 		KUNIT_EXPECT_EQ(test, ec_dev->dout_size, 0xbe + EC_MAX_REQUEST_OVERHEAD);
 	}
 
-	/* For cros_ec_host_command_proto_query() with passthru. */
+	/* For fill_protocol_info() with passthru. */
 	{
 		mock = cros_kunit_ec_xfer_mock_next();
 		KUNIT_EXPECT_PTR_NE(test, mock, NULL);
@@ -348,7 +348,7 @@ static void cros_ec_proto_test_query_all_no_pd(struct kunit *test)
 	struct ec_xfer_mock *mock;
 	int ret;
 
-	/* For cros_ec_host_command_proto_query() without passthru. */
+	/* For fill_protocol_info() without passthru. */
 	{
 		struct ec_response_get_protocol_info *data;
 
@@ -364,7 +364,7 @@ static void cros_ec_proto_test_query_all_no_pd(struct kunit *test)
 		data->max_response_packet_size = 0xef;
 	}
 
-	/* For cros_ec_host_command_proto_query() with passthru. */
+	/* For fill_protocol_info() with passthru. */
 	{
 		mock = cros_kunit_ec_xfer_mock_addx(test, 0, EC_RES_INVALID_COMMAND,
 						    sizeof(struct ec_response_get_protocol_info));
@@ -375,7 +375,7 @@ static void cros_ec_proto_test_query_all_no_pd(struct kunit *test)
 	ret = cros_ec_query_all(ec_dev);
 	KUNIT_EXPECT_EQ(test, ret, 0);
 
-	/* For cros_ec_host_command_proto_query() without passthru. */
+	/* For fill_protocol_info() without passthru. */
 	{
 		mock = cros_kunit_ec_xfer_mock_next();
 		KUNIT_EXPECT_PTR_NE(test, mock, NULL);
@@ -387,7 +387,7 @@ static void cros_ec_proto_test_query_all_no_pd(struct kunit *test)
 		KUNIT_EXPECT_EQ(test, mock->msg.outsize, 0);
 	}
 
-	/* For cros_ec_host_command_proto_query() with passthru. */
+	/* For fill_protocol_info() with passthru. */
 	{
 		mock = cros_kunit_ec_xfer_mock_next();
 		KUNIT_EXPECT_PTR_NE(test, mock, NULL);
@@ -411,7 +411,7 @@ static void cros_ec_proto_test_query_all_legacy_normal(struct kunit *test)
 	struct ec_xfer_mock *mock;
 	int ret;
 
-	/* For cros_ec_host_command_proto_query() without passthru. */
+	/* For fill_protocol_info() without passthru. */
 	{
 		mock = cros_kunit_ec_xfer_mock_addx(test, 0, EC_RES_INVALID_COMMAND,
 						    sizeof(struct ec_response_get_protocol_info));
@@ -433,7 +433,7 @@ static void cros_ec_proto_test_query_all_legacy_normal(struct kunit *test)
 	ret = cros_ec_query_all(ec_dev);
 	KUNIT_EXPECT_EQ(test, ret, 0);
 
-	/* For cros_ec_host_command_proto_query() without passthru. */
+	/* For fill_protocol_info() without passthru. */
 	{
 		mock = cros_kunit_ec_xfer_mock_next();
 		KUNIT_EXPECT_PTR_NE(test, mock, NULL);
@@ -771,7 +771,7 @@ static void cros_ec_proto_test_query_all_default_wake_mask(struct kunit *test)
 	/* Set some garbage bytes. */
 	ec_dev->host_event_wake_mask = U32_MAX;
 
-	/* For cros_ec_host_command_proto_query() without passthru. */
+	/* For fill_protocol_info() without passthru. */
 	{
 		struct ec_response_get_protocol_info *data;
 
@@ -787,7 +787,7 @@ static void cros_ec_proto_test_query_all_default_wake_mask(struct kunit *test)
 		data->max_response_packet_size = 0xef;
 	}
 
-	/* For cros_ec_host_command_proto_query() with passthru. */
+	/* For fill_protocol_info() with passthru. */
 	{
 		mock = cros_kunit_ec_xfer_mock_addx(test, 0, EC_RES_INVALID_COMMAND,
 						    sizeof(struct ec_response_get_protocol_info));
@@ -819,7 +819,7 @@ static void cros_ec_proto_test_query_all_default_wake_mask(struct kunit *test)
 	ret = cros_ec_query_all(ec_dev);
 	KUNIT_EXPECT_EQ(test, ret, 0);
 
-	/* For cros_ec_host_command_proto_query() without passthru. */
+	/* For fill_protocol_info() without passthru. */
 	{
 		mock = cros_kunit_ec_xfer_mock_next();
 		KUNIT_EXPECT_PTR_NE(test, mock, NULL);
@@ -831,7 +831,7 @@ static void cros_ec_proto_test_query_all_default_wake_mask(struct kunit *test)
 		KUNIT_EXPECT_EQ(test, mock->msg.outsize, 0);
 	}
 
-	/* For cros_ec_host_command_proto_query() with passthru. */
+	/* For fill_protocol_info() with passthru. */
 	{
 		mock = cros_kunit_ec_xfer_mock_next();
 		KUNIT_EXPECT_PTR_NE(test, mock, NULL);
-- 
2.36.1.255.ge46751e96f-goog