[PATCH net-next] eth: fbnic: Read module EEPROM

[Mohsin Bashir <mohsin.bashr@gmail.com>]

Add support to read module EEPROM for fbnic. Towards this, add required
support to issue a new command to the firmware and to receive the response
to the corresponding command.

Create a local copy of the data in the completion struct before writing to
ethtool_module_eeprom to avoid writing to data in case it is freed. Given
that EEPROM pages are small, the overhead of additional copy is
negligible.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Mohsin Bashir <mohsin.bashr@gmail.com>
---
 .../net/ethernet/meta/fbnic/fbnic_ethtool.c   |  66 +++++++++
 drivers/net/ethernet/meta/fbnic/fbnic_fw.c    | 135 ++++++++++++++++++
 drivers/net/ethernet/meta/fbnic/fbnic_fw.h    |  22 +++
 3 files changed, 223 insertions(+)

diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
index b4ff98ee2051..f6069cddffa5 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_ethtool.c
@@ -1635,6 +1635,71 @@ static void fbnic_get_ts_stats(struct net_device *netdev,
 	}
 }
 
+static int
+fbnic_get_module_eeprom_by_page(struct net_device *netdev,
+				const struct ethtool_module_eeprom *page_data,
+				struct netlink_ext_ack *extack)
+{
+	struct fbnic_net *fbn = netdev_priv(netdev);
+	struct fbnic_fw_completion *fw_cmpl;
+	struct fbnic_dev *fbd = fbn->fbd;
+	int err;
+
+	if (page_data->i2c_address != 0x50) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Invalid i2c address. Only 0x50 is supported");
+		return -EINVAL;
+	}
+
+	if (page_data->bank != 0) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Invalid bank. Only 0 is supported");
+		return -EINVAL;
+	}
+
+	fw_cmpl = __fbnic_fw_alloc_cmpl(FBNIC_TLV_MSG_ID_QSFP_READ_RESP,
+					page_data->length);
+	if (!fw_cmpl)
+		return -ENOMEM;
+
+	/* Initialize completion and queue it for FW to process */
+	fw_cmpl->u.qsfp.length = page_data->length;
+	fw_cmpl->u.qsfp.offset = page_data->offset;
+	fw_cmpl->u.qsfp.page = page_data->page;
+	fw_cmpl->u.qsfp.bank = page_data->bank;
+
+	err = fbnic_fw_xmit_qsfp_read_msg(fbd, fw_cmpl, page_data->page,
+					  page_data->bank, page_data->offset,
+					  page_data->length);
+	if (err) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Failed to transmit EEPROM read request");
+		goto exit_free;
+	}
+
+	if (!wait_for_completion_timeout(&fw_cmpl->done, 2 * HZ)) {
+		err = -ETIMEDOUT;
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Timed out waiting for firmware response");
+		goto exit_cleanup;
+	}
+
+	if (fw_cmpl->result) {
+		err = fw_cmpl->result;
+		NL_SET_ERR_MSG_MOD(extack, "Failed to read EEPROM");
+		goto exit_cleanup;
+	}
+
+	memcpy(page_data->data, fw_cmpl->u.qsfp.data, page_data->length);
+
+exit_cleanup:
+	fbnic_mbx_clear_cmpl(fbd, fw_cmpl);
+exit_free:
+	fbnic_fw_put_cmpl(fw_cmpl);
+
+	return err ? : page_data->length;
+}
+
 static void fbnic_set_counter(u64 *stat, struct fbnic_stat_counter *counter)
 {
 	if (counter->reported)
@@ -1841,6 +1906,7 @@ static const struct ethtool_ops fbnic_ethtool_ops = {
 	.get_link_ksettings		= fbnic_phylink_ethtool_ksettings_get,
 	.get_fec_stats			= fbnic_get_fec_stats,
 	.get_fecparam			= fbnic_phylink_get_fecparam,
+	.get_module_eeprom_by_page	= fbnic_get_module_eeprom_by_page,
 	.get_eth_phy_stats		= fbnic_get_eth_phy_stats,
 	.get_eth_mac_stats		= fbnic_get_eth_mac_stats,
 	.get_eth_ctrl_stats		= fbnic_get_eth_ctrl_stats,
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_fw.c b/drivers/net/ethernet/meta/fbnic/fbnic_fw.c
index 6c3e7f81a2ed..c87cb9ed09e7 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_fw.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_fw.c
@@ -1184,6 +1184,138 @@ static int fbnic_fw_parse_fw_finish_upgrade_req(void *opaque,
 	return 0;
 }
 
+/**
+ * fbnic_fw_xmit_qsfp_read_msg - Transmit a QSFP read request
+ * @fbd: FBNIC device structure
+ * @cmpl_data: Structure to store EEPROM response in
+ * @page: Refers to page number on page enabled QSFP modules
+ * @bank: Refers to a collection of pages
+ * @offset: Offset into QSFP EEPROM requested
+ * @length: Length of section of QSFP EEPROM to fetch
+ *
+ * Return: zero on success, negative value on failure
+ *
+ * Asks the firmware to provide a section of the QSFP EEPROM back in a
+ * message. The response will have an offset and size matching the values
+ * provided.
+ */
+int fbnic_fw_xmit_qsfp_read_msg(struct fbnic_dev *fbd,
+				struct fbnic_fw_completion *cmpl_data,
+				u32 page, u32 bank, u32 offset, u32 length)
+{
+	struct fbnic_tlv_msg *msg;
+	int err = 0;
+
+	if (!length || length > TLV_MAX_DATA)
+		return -EINVAL;
+
+	msg = fbnic_tlv_msg_alloc(FBNIC_TLV_MSG_ID_QSFP_READ_REQ);
+	if (!msg)
+		return -ENOMEM;
+
+	err = fbnic_tlv_attr_put_int(msg, FBNIC_FW_QSFP_BANK, bank);
+	if (err)
+		goto free_message;
+
+	err = fbnic_tlv_attr_put_int(msg, FBNIC_FW_QSFP_PAGE, page);
+	if (err)
+		goto free_message;
+
+	err = fbnic_tlv_attr_put_int(msg, FBNIC_FW_QSFP_OFFSET, offset);
+	if (err)
+		goto free_message;
+
+	err = fbnic_tlv_attr_put_int(msg, FBNIC_FW_QSFP_LENGTH, length);
+	if (err)
+		goto free_message;
+
+	err = fbnic_mbx_map_req_w_cmpl(fbd, msg, cmpl_data);
+	if (err)
+		goto free_message;
+
+	return 0;
+
+free_message:
+	free_page((unsigned long)msg);
+	return err;
+}
+
+static const struct fbnic_tlv_index fbnic_qsfp_read_resp_index[] = {
+	FBNIC_TLV_ATTR_U32(FBNIC_FW_QSFP_BANK),
+	FBNIC_TLV_ATTR_U32(FBNIC_FW_QSFP_PAGE),
+	FBNIC_TLV_ATTR_U32(FBNIC_FW_QSFP_OFFSET),
+	FBNIC_TLV_ATTR_U32(FBNIC_FW_QSFP_LENGTH),
+	FBNIC_TLV_ATTR_RAW_DATA(FBNIC_FW_QSFP_DATA),
+	FBNIC_TLV_ATTR_S32(FBNIC_FW_QSFP_ERROR),
+	FBNIC_TLV_ATTR_LAST
+};
+
+static int fbnic_fw_parse_qsfp_read_resp(void *opaque,
+					 struct fbnic_tlv_msg **results)
+{
+	struct fbnic_fw_completion *cmpl_data;
+	struct fbnic_dev *fbd = opaque;
+	struct fbnic_tlv_msg *data_hdr;
+	u32 length, offset, page, bank;
+	u8 *data;
+	s32 err;
+
+	/* Verify we have a completion pointer to provide with data */
+	cmpl_data = fbnic_fw_get_cmpl_by_type(fbd,
+					      FBNIC_TLV_MSG_ID_QSFP_READ_RESP);
+	if (!cmpl_data)
+		return -ENOSPC;
+
+	bank = fta_get_uint(results, FBNIC_FW_QSFP_BANK);
+	if (bank != cmpl_data->u.qsfp.bank) {
+		dev_warn(fbd->dev, "bank not equal to bank requested: %d vs %d\n",
+			 bank, cmpl_data->u.qsfp.bank);
+		err = -EINVAL;
+		goto msg_err;
+	}
+
+	page = fta_get_uint(results, FBNIC_FW_QSFP_PAGE);
+	if (page != cmpl_data->u.qsfp.page) {
+		dev_warn(fbd->dev, "page not equal to page requested: %d vs %d\n",
+			 page, cmpl_data->u.qsfp.page);
+		err = -EINVAL;
+		goto msg_err;
+	}
+
+	offset = fta_get_uint(results, FBNIC_FW_QSFP_OFFSET);
+	length = fta_get_uint(results, FBNIC_FW_QSFP_LENGTH);
+
+	if (length != cmpl_data->u.qsfp.length ||
+	    offset != cmpl_data->u.qsfp.offset) {
+		dev_warn(fbd->dev,
+			 "offset/length not equal to size requested: %d/%d vs %d/%d\n",
+			 offset, length,
+			 cmpl_data->u.qsfp.offset, cmpl_data->u.qsfp.length);
+		err = -EINVAL;
+		goto msg_err;
+	}
+
+	err = fta_get_sint(results, FBNIC_FW_QSFP_ERROR);
+	if (err)
+		goto msg_err;
+
+	data_hdr = results[FBNIC_FW_QSFP_DATA];
+	if (!data_hdr) {
+		err = -ENODATA;
+		goto msg_err;
+	}
+
+	/* Copy data */
+	data = fbnic_tlv_attr_get_value_ptr(data_hdr);
+	memcpy(cmpl_data->u.qsfp.data, data, length);
+msg_err:
+	cmpl_data->result = err;
+	complete(&cmpl_data->done);
+	fbnic_fw_put_cmpl(cmpl_data);
+
+	return err;
+}
+
 /**
  * fbnic_fw_xmit_tsene_read_msg - Create and transmit a sensor read request
  * @fbd: FBNIC device structure
@@ -1445,6 +1577,9 @@ static const struct fbnic_tlv_parser fbnic_fw_tlv_parser[] = {
 	FBNIC_TLV_PARSER(FW_FINISH_UPGRADE_REQ,
 			 fbnic_fw_finish_upgrade_req_index,
 			 fbnic_fw_parse_fw_finish_upgrade_req),
+	FBNIC_TLV_PARSER(QSFP_READ_RESP,
+			 fbnic_qsfp_read_resp_index,
+			 fbnic_fw_parse_qsfp_read_resp),
 	FBNIC_TLV_PARSER(TSENE_READ_RESP,
 			 fbnic_tsene_read_resp_index,
 			 fbnic_fw_parse_tsene_read_resp),
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_fw.h b/drivers/net/ethernet/meta/fbnic/fbnic_fw.h
index d776be9fc7f7..1ecd777aaada 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_fw.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_fw.h
@@ -78,6 +78,13 @@ struct fbnic_fw_completion {
 			u32 offset;
 			u32 length;
 		} fw_update;
+		struct {
+			u16 length;
+			u8 offset;
+			u8 page;
+			u8 bank;
+			u8 data[] __aligned(sizeof(u32)) __counted_by(length);
+		} qsfp;
 		struct {
 			s32 millivolts;
 			s32 millidegrees;
@@ -109,6 +116,9 @@ int fbnic_fw_xmit_fw_start_upgrade(struct fbnic_dev *fbd,
 int fbnic_fw_xmit_fw_write_chunk(struct fbnic_dev *fbd,
 				 const u8 *data, u32 offset, u16 length,
 				 int cancel_error);
+int fbnic_fw_xmit_qsfp_read_msg(struct fbnic_dev *fbd,
+				struct fbnic_fw_completion *cmpl_data,
+				u32 page, u32 bank, u32 offset, u32 length);
 int fbnic_fw_xmit_tsene_read_msg(struct fbnic_dev *fbd,
 				 struct fbnic_fw_completion *cmpl_data);
 int fbnic_fw_xmit_send_logs(struct fbnic_dev *fbd, bool enable,
@@ -161,6 +171,8 @@ enum {
 	FBNIC_TLV_MSG_ID_FW_WRITE_CHUNK_RESP		= 0x25,
 	FBNIC_TLV_MSG_ID_FW_FINISH_UPGRADE_REQ		= 0x28,
 	FBNIC_TLV_MSG_ID_FW_FINISH_UPGRADE_RESP		= 0x29,
+	FBNIC_TLV_MSG_ID_QSFP_READ_REQ			= 0x38,
+	FBNIC_TLV_MSG_ID_QSFP_READ_RESP			= 0x39,
 	FBNIC_TLV_MSG_ID_TSENE_READ_REQ			= 0x3C,
 	FBNIC_TLV_MSG_ID_TSENE_READ_RESP		= 0x3D,
 	FBNIC_TLV_MSG_ID_LOG_SEND_LOGS_REQ		= 0x43,
@@ -209,6 +221,16 @@ enum {
 	FBNIC_FW_LINK_FEC_BASER			= 3,
 };
 
+enum {
+	FBNIC_FW_QSFP_BANK			= 0x0,
+	FBNIC_FW_QSFP_PAGE			= 0x1,
+	FBNIC_FW_QSFP_OFFSET			= 0x2,
+	FBNIC_FW_QSFP_LENGTH			= 0x3,
+	FBNIC_FW_QSFP_ERROR			= 0x4,
+	FBNIC_FW_QSFP_DATA			= 0x5,
+	FBNIC_FW_QSFP_MSG_MAX
+};
+
 enum {
 	FBNIC_FW_TSENE_THERM			= 0x0,
 	FBNIC_FW_TSENE_VOLT			= 0x1,
-- 
2.47.3