diff mbox series

[net-next,1/2] net: ethtool: Add new parameters and a function to support EPL

Message ID 20240906055700.2645281-2-danieller@nvidia.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series ethtool: Add support for writing firmware | expand

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netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 16 this patch: 16
netdev/build_tools success No tools touched, skip
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netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 16 this patch: 16
netdev/checkpatch warning WARNING: line length of 83 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
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netdev/source_inline success Was 0 now: 0

Commit Message

Danielle Ratson Sept. 6, 2024, 5:56 a.m. UTC 
In the CMIS specification for pluggable modules, LPL (Low-Priority Payload)
and EPL (Extended Payload Length) are two types of data payloads used for
managing various functions and features of the module.

EPL payloads are used for more complex and extensive management
functions that require a larger amount of data, so writing firmware
blocks using EPL is much more efficient.

Currently, only LPL payload is supported for writing firmware blocks to
the module.

Add EPL related parameters to the function ethtool_cmis_cdb_compose_args()
and add a specific function for calculating the maximum allowable length
extension for EPL. Both will be used in the next patch to add support for
writing firmware blocks using EPL.

Signed-off-by: Danielle Ratson <danieller@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
---
 net/ethtool/cmis.h           | 12 +++++++-----
 net/ethtool/cmis_cdb.c       | 32 +++++++++++++++++++++-----------
 net/ethtool/cmis_fw_update.c | 17 ++++++++++-------
 3 files changed, 38 insertions(+), 23 deletions(-)

Comments

Andrew Lunn Sept. 6, 2024, 3:36 p.m. UTC | #1 
> +/* For accessing the EPL field on page 9Fh, the allowable length extension is
> + * min(i, 255) byte octets where i specifies the allowable additional number of
> + * byte octets in a READ or a WRITE.
> + */
> +u32 ethtool_cmis_get_max_epl_size(u8 num_of_byte_octs)
> +{
> +	return 8 * (1 + min_t(u8, num_of_byte_octs, 255));
> +}

Does this get mapped to a 255 byte I2C bus transfer?

https://elixir.bootlin.com/linux/v6.11-rc6/source/drivers/net/phy/sfp.c#L218

/* SFP_EEPROM_BLOCK_SIZE is the size of data chunk to read the EEPROM
 * at a time. Some SFP modules and also some Linux I2C drivers do not like
 * reads longer than 16 bytes.
 */
#define SFP_EEPROM_BLOCK_SIZE	16

If an SMBUS is being used, rather than I2C, there is a hard limit of
32 bytes in a message transfer.

I've not looked in details at these patches, but maybe you need a
mechanism to ask the hardware or I2C driver what it can actually do?
Is it possible to say LPL is the only choice?

	Andrew
Danielle Ratson Sept. 8, 2024, 12:33 p.m. UTC | #2 
> From: Andrew Lunn <andrew@lunn.ch>
> Sent: Friday, 6 September 2024 18:36
> To: Danielle Ratson <danieller@nvidia.com>
> Cc: netdev@vger.kernel.org; davem@davemloft.net; edumazet@google.com;
> kuba@kernel.org; pabeni@redhat.com; yuehaibing@huawei.com; linux-
> kernel@vger.kernel.org; Petr Machata <petrm@nvidia.com>
> Subject: Re: [PATCH net-next 1/2] net: ethtool: Add new parameters and a
> function to support EPL
> 
> > +/* For accessing the EPL field on page 9Fh, the allowable length
> > +extension is
> > + * min(i, 255) byte octets where i specifies the allowable additional
> > +number of
> > + * byte octets in a READ or a WRITE.
> > + */
> > +u32 ethtool_cmis_get_max_epl_size(u8 num_of_byte_octs) {
> > +	return 8 * (1 + min_t(u8, num_of_byte_octs, 255)); }
> 
> Does this get mapped to a 255 byte I2C bus transfer?
> 
> https://elixir.bootlin.com/linux/v6.11-rc6/source/drivers/net/phy/sfp.c#L218
> 
> /* SFP_EEPROM_BLOCK_SIZE is the size of data chunk to read the EEPROM
>  * at a time. Some SFP modules and also some Linux I2C drivers do not like
>  * reads longer than 16 bytes.
>  */
> #define SFP_EEPROM_BLOCK_SIZE	16
> 
> If an SMBUS is being used, rather than I2C, there is a hard limit of
> 32 bytes in a message transfer.
> 
> I've not looked in details at these patches, but maybe you need a mechanism
> to ask the hardware or I2C driver what it can actually do?
> Is it possible to say LPL is the only choice?
> 
> 	Andrew

Hi Andrew,

Thanks for your reply.

As I wrote in the commit message, the EPL is an extended type of data payload in which you can send the firmware image, for example, in blocks.
The LPL contains ap to 128 bytes, and the EPL up to 2048. The exact allowed extension can be derived from the 'readWriteLengthExt' and the two functions (ethtool_cmis_get_max_lpl/epl_size ()) that calculates the specific value of the module from it.

The obligations on the chunks that are related to the bus type limit, should be referred to in the driver itself. 
The driver should be the responsible for bus that cannot read/write larger chunks and then split it to the supported size chunks accordingly. 

Hope it makes more sense now.

Thanks,
Danielle
diff mbox series

Patch

diff --git a/net/ethtool/cmis.h b/net/ethtool/cmis.h
index 3e7c293af78c..73a5060d0f4c 100644
--- a/net/ethtool/cmis.h
+++ b/net/ethtool/cmis.h
@@ -96,13 +96,15 @@  struct ethtool_cmis_cdb_rpl {
 	u8 payload[ETHTOOL_CMIS_CDB_LPL_MAX_PL_LENGTH];
 };
 
-u32 ethtool_cmis_get_max_payload_size(u8 num_of_byte_octs);
+u32 ethtool_cmis_get_max_lpl_size(u8 num_of_byte_octs);
+u32 ethtool_cmis_get_max_epl_size(u8 num_of_byte_octs);
 
 void ethtool_cmis_cdb_compose_args(struct ethtool_cmis_cdb_cmd_args *args,
-				   enum ethtool_cmis_cdb_cmd_id cmd, u8 *pl,
-				   u8 lpl_len, u16 max_duration,
-				   u8 read_write_len_ext, u16 msleep_pre_rpl,
-				   u8 rpl_exp_len, u8 flags);
+				   enum ethtool_cmis_cdb_cmd_id cmd, u8 *lpl,
+				   u8 lpl_len, u8 *epl, u16 epl_len,
+				   u16 max_duration, u8 read_write_len_ext,
+				   u16 msleep_pre_rpl, u8 rpl_exp_len,
+				   u8 flags);
 
 void ethtool_cmis_cdb_check_completion_flag(u8 cmis_rev, u8 *flags);
 
diff --git a/net/ethtool/cmis_cdb.c b/net/ethtool/cmis_cdb.c
index 1bb08783b60d..f599b20479f6 100644
--- a/net/ethtool/cmis_cdb.c
+++ b/net/ethtool/cmis_cdb.c
@@ -11,25 +11,34 @@ 
  * min(i, 15) byte octets where i specifies the allowable additional number of
  * byte octets in a READ or a WRITE.
  */
-u32 ethtool_cmis_get_max_payload_size(u8 num_of_byte_octs)
+u32 ethtool_cmis_get_max_lpl_size(u8 num_of_byte_octs)
 {
 	return 8 * (1 + min_t(u8, num_of_byte_octs, 15));
 }
 
+/* For accessing the EPL field on page 9Fh, the allowable length extension is
+ * min(i, 255) byte octets where i specifies the allowable additional number of
+ * byte octets in a READ or a WRITE.
+ */
+u32 ethtool_cmis_get_max_epl_size(u8 num_of_byte_octs)
+{
+	return 8 * (1 + min_t(u8, num_of_byte_octs, 255));
+}
+
 void ethtool_cmis_cdb_compose_args(struct ethtool_cmis_cdb_cmd_args *args,
-				   enum ethtool_cmis_cdb_cmd_id cmd, u8 *pl,
-				   u8 lpl_len, u16 max_duration,
-				   u8 read_write_len_ext, u16 msleep_pre_rpl,
-				   u8 rpl_exp_len, u8 flags)
+				   enum ethtool_cmis_cdb_cmd_id cmd, u8 *lpl,
+				   u8 lpl_len, u8 *epl, u16 epl_len,
+				   u16 max_duration, u8 read_write_len_ext,
+				   u16 msleep_pre_rpl, u8 rpl_exp_len, u8 flags)
 {
 	args->req.id = cpu_to_be16(cmd);
 	args->req.lpl_len = lpl_len;
-	if (pl)
-		memcpy(args->req.payload, pl, args->req.lpl_len);
+	if (lpl)
+		memcpy(args->req.payload, lpl, args->req.lpl_len);
 
 	args->max_duration = max_duration;
 	args->read_write_len_ext =
-		ethtool_cmis_get_max_payload_size(read_write_len_ext);
+		ethtool_cmis_get_max_lpl_size(read_write_len_ext);
 	args->msleep_pre_rpl = msleep_pre_rpl;
 	args->rpl_exp_len = rpl_exp_len;
 	args->flags = flags;
@@ -178,7 +187,7 @@  cmis_cdb_validate_password(struct ethtool_cmis_cdb *cdb,
 	}
 
 	ethtool_cmis_cdb_compose_args(&args, ETHTOOL_CMIS_CDB_CMD_QUERY_STATUS,
-				      (u8 *)&qs_pl, sizeof(qs_pl), 0,
+				      (u8 *)&qs_pl, sizeof(qs_pl), NULL, 0, 0,
 				      cdb->read_write_len_ext, 1000,
 				      sizeof(*rpl),
 				      CDB_F_COMPLETION_VALID | CDB_F_STATUS_VALID);
@@ -240,8 +249,9 @@  static int cmis_cdb_module_features_get(struct ethtool_cmis_cdb *cdb,
 	ethtool_cmis_cdb_check_completion_flag(cdb->cmis_rev, &flags);
 	ethtool_cmis_cdb_compose_args(&args,
 				      ETHTOOL_CMIS_CDB_CMD_MODULE_FEATURES,
-				      NULL, 0, 0, cdb->read_write_len_ext,
-				      1000, sizeof(*rpl), flags);
+				      NULL, 0, NULL, 0, 0,
+				      cdb->read_write_len_ext, 1000,
+				      sizeof(*rpl), flags);
 
 	err = ethtool_cmis_cdb_execute_cmd(dev, &args);
 	if (err < 0) {
diff --git a/net/ethtool/cmis_fw_update.c b/net/ethtool/cmis_fw_update.c
index 655ff5224ffa..a514127985d4 100644
--- a/net/ethtool/cmis_fw_update.c
+++ b/net/ethtool/cmis_fw_update.c
@@ -54,7 +54,8 @@  cmis_fw_update_fw_mng_features_get(struct ethtool_cmis_cdb *cdb,
 	ethtool_cmis_cdb_check_completion_flag(cdb->cmis_rev, &flags);
 	ethtool_cmis_cdb_compose_args(&args,
 				      ETHTOOL_CMIS_CDB_CMD_FW_MANAGMENT_FEATURES,
-				      NULL, 0, cdb->max_completion_time,
+				      NULL, 0, NULL, 0,
+				      cdb->max_completion_time,
 				      cdb->read_write_len_ext, 1000,
 				      sizeof(*rpl), flags);
 
@@ -122,7 +123,7 @@  cmis_fw_update_start_download(struct ethtool_cmis_cdb *cdb,
 
 	ethtool_cmis_cdb_compose_args(&args,
 				      ETHTOOL_CMIS_CDB_CMD_START_FW_DOWNLOAD,
-				      (u8 *)&pl, lpl_len,
+				      (u8 *)&pl, lpl_len, NULL, 0,
 				      fw_mng->max_duration_start,
 				      cdb->read_write_len_ext, 1000, 0,
 				      CDB_F_COMPLETION_VALID | CDB_F_STATUS_VALID);
@@ -158,7 +159,7 @@  cmis_fw_update_write_image(struct ethtool_cmis_cdb *cdb,
 	int err;
 
 	max_lpl_len = min_t(u32,
-			    ethtool_cmis_get_max_payload_size(cdb->read_write_len_ext),
+			    ethtool_cmis_get_max_lpl_size(cdb->read_write_len_ext),
 			    ETHTOOL_CMIS_CDB_LPL_MAX_PL_LENGTH);
 	max_block_size =
 		max_lpl_len - sizeof_field(struct cmis_cdb_write_fw_block_lpl_pl,
@@ -183,7 +184,7 @@  cmis_fw_update_write_image(struct ethtool_cmis_cdb *cdb,
 
 		ethtool_cmis_cdb_compose_args(&args,
 					      ETHTOOL_CMIS_CDB_CMD_WRITE_FW_BLOCK_LPL,
-					      (u8 *)&pl, lpl_len,
+					      (u8 *)&pl, lpl_len, NULL, 0,
 					      fw_mng->max_duration_write,
 					      cdb->read_write_len_ext, 1, 0,
 					      CDB_F_COMPLETION_VALID | CDB_F_STATUS_VALID);
@@ -212,7 +213,8 @@  cmis_fw_update_complete_download(struct ethtool_cmis_cdb *cdb,
 
 	ethtool_cmis_cdb_compose_args(&args,
 				      ETHTOOL_CMIS_CDB_CMD_COMPLETE_FW_DOWNLOAD,
-				      NULL, 0, fw_mng->max_duration_complete,
+				      NULL, 0, NULL, 0,
+				      fw_mng->max_duration_complete,
 				      cdb->read_write_len_ext, 1000, 0,
 				      CDB_F_COMPLETION_VALID | CDB_F_STATUS_VALID);
 
@@ -294,7 +296,7 @@  cmis_fw_update_run_image(struct ethtool_cmis_cdb *cdb, struct net_device *dev,
 	int err;
 
 	ethtool_cmis_cdb_compose_args(&args, ETHTOOL_CMIS_CDB_CMD_RUN_FW_IMAGE,
-				      (u8 *)&pl, sizeof(pl),
+				      (u8 *)&pl, sizeof(pl), NULL, 0,
 				      cdb->max_completion_time,
 				      cdb->read_write_len_ext, 1000, 0,
 				      CDB_F_MODULE_STATE_VALID);
@@ -326,7 +328,8 @@  cmis_fw_update_commit_image(struct ethtool_cmis_cdb *cdb,
 
 	ethtool_cmis_cdb_compose_args(&args,
 				      ETHTOOL_CMIS_CDB_CMD_COMMIT_FW_IMAGE,
-				      NULL, 0, cdb->max_completion_time,
+				      NULL, 0, NULL, 0,
+				      cdb->max_completion_time,
 				      cdb->read_write_len_ext, 1000, 0,
 				      CDB_F_COMPLETION_VALID | CDB_F_STATUS_VALID);