diff mbox series

[net-next,07/10] ethtool: cmis_cdb: Add a layer for supporting CDB commands

Message ID 20240408125340.2084269-8-danieller@nvidia.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series Add ability to flash modules' firmware | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next, async
netdev/apply fail Patch does not apply to net-next-0

Commit Message

Danielle Ratson April 8, 2024, 12:53 p.m. UTC
CDB (Command Data Block Message Communication) reads and writes are
performed on memory map pages 9Fh-AFh according to the CMIS standard,
section 8.20 of revision 5.2.
Page 9Fh is used to specify the CDB command to be executed and also
provides an area for a local payload (LPL).

According to the CMIS standard, the firmware update process is done using
a CDB commands sequence that will be implemented in the next patch.

The kernel interface that will implement the firmware update using CDB
command will include 2 layers that will be added under ethtool:

* The upper layer that will be triggered from the module layer, is
  cmis_fw_update.
* The lower one is cmis_cdb.

In the future there might be more operations to implement using CDB
commands. Therefore, the idea is to keep the CDB interface clean and the
cmis_fw_update specific to the CDB commands handling it.

These two layers will communicate using the API the consists of three
functions:

- struct ethtool_cmis_cdb *
  ethtool_cmis_cdb_init(struct net_device *dev,
			struct ethtool_module_fw_flash_params *params);
- void ethtool_cmis_cdb_fini(struct ethtool_cmis_cdb *cdb);
- int ethtool_cmis_cdb_execute_cmd(struct net_device *dev,
				   struct ethtool_cmis_cdb_cmd_args *args);

Add the CDB layer to support initializing, finishing and executing CDB
commands:

* The initialization process will include creating of an ethtool_cmis_cdb
  instance, querying the module CDB support, entering and validating the
  password from user space (CMD 0x0000) and querying the module features
  (CMD 0x0040).

* The finishing API will simply free the ethtool_cmis_cdb instance.

* The executing process will write the CDB command to EEPROM using
  set_module_eeprom_by_page() that was presented earlier, and will
  process the reply from EEPROM.

Signed-off-by: Danielle Ratson <danieller@nvidia.com>
---
 net/ethtool/Makefile    |   2 +-
 net/ethtool/cmis.h      | 114 +++++++++
 net/ethtool/cmis_cdb.c  | 549 ++++++++++++++++++++++++++++++++++++++++
 net/ethtool/module_fw.h |  10 +
 4 files changed, 674 insertions(+), 1 deletion(-)
 create mode 100644 net/ethtool/cmis.h
 create mode 100644 net/ethtool/cmis_cdb.c

Comments

Russell King (Oracle) April 8, 2024, 2:55 p.m. UTC | #1
On Mon, Apr 08, 2024 at 03:53:37PM +0300, Danielle Ratson wrote:
> +/**
> + * struct ethtool_cmis_cdb_request - CDB commands request fields as decribed in
> + *				the CMIS standard
> + * @id: Command ID.
> + * @epl_len: EPL memory length.
> + * @lpl_len: LPL memory length.
> + * @chk_code: Check code for the previous field and the payload.
> + * @resv1: Added to match the CMIS standard request continuity.
> + * @resv2: Added to match the CMIS standard request continuity.
> + * @payload: Payload for the CDB commands.
> + */
> +struct ethtool_cmis_cdb_request {
> +	__be16 id;
> +	struct_group(body,
> +		u16 epl_len;

u16 with a struct that also uses __be16 looks suspicious.

> +		u8 lpl_len;
> +		u8 chk_code;
> +		u8 resv1;
> +		u8 resv2;
> +		u8 payload[ETHTOOL_CMIS_CDB_LPL_MAX_PL_LENGTH];
> +	);

Does it matter if the compiler inserts some padding before this struct
group?

> +/**
> + * struct ethtool_cmis_cdb_rpl_hdr - CDB commands reply header arguments
> + * @rpl_len: Reply length.
> + * @rpl_chk_code: Reply check code.
> + */
> +struct ethtool_cmis_cdb_rpl_hdr {
> +	u8 rpl_len;
> +	u8 rpl_chk_code;

Does it matter if the compiler adds some padding here?
Matthew Wilcox April 8, 2024, 4:10 p.m. UTC | #2
On Mon, Apr 08, 2024 at 03:55:19PM +0100, Russell King (Oracle) wrote:
> On Mon, Apr 08, 2024 at 03:53:37PM +0300, Danielle Ratson wrote:
> > +/**
> > + * struct ethtool_cmis_cdb_request - CDB commands request fields as decribed in
> > + *				the CMIS standard
> > + * @id: Command ID.
> > + * @epl_len: EPL memory length.
> > + * @lpl_len: LPL memory length.
> > + * @chk_code: Check code for the previous field and the payload.
> > + * @resv1: Added to match the CMIS standard request continuity.
> > + * @resv2: Added to match the CMIS standard request continuity.
> > + * @payload: Payload for the CDB commands.
> > + */
> > +struct ethtool_cmis_cdb_request {
> > +	__be16 id;
> > +	struct_group(body,
> > +		u16 epl_len;
> 
> u16 with a struct that also uses __be16 looks suspicious.

I'd understand if it were the other way around.  The command ID isn't a
_number_, it's an ID.  You can't add 1 to it and get a meaningful requilt;
all you can do is check it for equality, so a u16 makes sense for an ID.
That's what I did in NVMe; command_id is typed as a __u16.

But a 'length' field is obviously a number.  You can meaningfully add
and subtract numbers to it.  If there's an endian consideration, that's
where you'd expect to see it.

So I concur, this is supicious.

(Oh, you might wonder why namespace ID (nsid) in the NVMe command is
an le32 rather than a u32, since it is also an ID.  And that's because
it's an ID which is exposed to userspace.  You wouldn't want to have big
endian systems call the namespace 16777216 and little endian systems
call it 1)
Danielle Ratson April 9, 2024, 10:58 a.m. UTC | #3
> -----Original Message-----
> From: Matthew Wilcox <willy@infradead.org>
> Sent: Monday, 8 April 2024 19:10
> To: Russell King (Oracle) <linux@armlinux.org.uk>
> Cc: Danielle Ratson <danieller@nvidia.com>; netdev@vger.kernel.org;
> davem@davemloft.net; edumazet@google.com; kuba@kernel.org;
> pabeni@redhat.com; corbet@lwn.net; sdf@google.com;
> kory.maincent@bootlin.com; maxime.chevallier@bootlin.com;
> vladimir.oltean@nxp.com; przemyslaw.kitszel@intel.com;
> ahmed.zaki@intel.com; richardcochran@gmail.com; shayagr@amazon.com;
> paul.greenwalt@intel.com; jiri@resnulli.us; linux-doc@vger.kernel.org; linux-
> kernel@vger.kernel.org; mlxsw <mlxsw@nvidia.com>; Petr Machata
> <petrm@nvidia.com>; Ido Schimmel <idosch@nvidia.com>
> Subject: Re: [PATCH net-next 07/10] ethtool: cmis_cdb: Add a layer for
> supporting CDB commands
> 
> On Mon, Apr 08, 2024 at 03:55:19PM +0100, Russell King (Oracle) wrote:
> > On Mon, Apr 08, 2024 at 03:53:37PM +0300, Danielle Ratson wrote:
> > > +/**
> > > + * struct ethtool_cmis_cdb_request - CDB commands request fields as
> decribed in
> > > + *				the CMIS standard
> > > + * @id: Command ID.
> > > + * @epl_len: EPL memory length.
> > > + * @lpl_len: LPL memory length.
> > > + * @chk_code: Check code for the previous field and the payload.
> > > + * @resv1: Added to match the CMIS standard request continuity.
> > > + * @resv2: Added to match the CMIS standard request continuity.
> > > + * @payload: Payload for the CDB commands.
> > > + */
> > > +struct ethtool_cmis_cdb_request {
> > > +	__be16 id;
> > > +	struct_group(body,
> > > +		u16 epl_len;
> >
> > u16 with a struct that also uses __be16 looks suspicious.
> 
> I'd understand if it were the other way around.  The command ID isn't a
> _number_, it's an ID.  You can't add 1 to it and get a meaningful requilt; all you
> can do is check it for equality, so a u16 makes sense for an ID.
> That's what I did in NVMe; command_id is typed as a __u16.
> 
> But a 'length' field is obviously a number.  You can meaningfully add and
> subtract numbers to it.  If there's an endian consideration, that's where you'd
> expect to see it.
> 
> So I concur, this is supicious.
> 
> (Oh, you might wonder why namespace ID (nsid) in the NVMe command is an
> le32 rather than a u32, since it is also an ID.  And that's because it's an ID
> which is exposed to userspace.  You wouldn't want to have big endian systems
> call the namespace 16777216 and little endian systems call it 1)

Hi,

Thank you two for the comment.
Yes, you are right. Does it make sense to you to define both as __be16? 

Thanks,
Danielle
Danielle Ratson April 9, 2024, 1:34 p.m. UTC | #4
> -----Original Message-----
> From: Russell King <linux@armlinux.org.uk>
> Sent: Monday, 8 April 2024 17:55
> To: Danielle Ratson <danieller@nvidia.com>
> Cc: netdev@vger.kernel.org; davem@davemloft.net; edumazet@google.com;
> kuba@kernel.org; pabeni@redhat.com; corbet@lwn.net; sdf@google.com;
> kory.maincent@bootlin.com; maxime.chevallier@bootlin.com;
> vladimir.oltean@nxp.com; przemyslaw.kitszel@intel.com;
> ahmed.zaki@intel.com; richardcochran@gmail.com; shayagr@amazon.com;
> paul.greenwalt@intel.com; jiri@resnulli.us; linux-doc@vger.kernel.org; linux-
> kernel@vger.kernel.org; mlxsw <mlxsw@nvidia.com>; Petr Machata
> <petrm@nvidia.com>; Ido Schimmel <idosch@nvidia.com>
> Subject: Re: [PATCH net-next 07/10] ethtool: cmis_cdb: Add a layer for
> supporting CDB commands
> 
> On Mon, Apr 08, 2024 at 03:53:37PM +0300, Danielle Ratson wrote:
> > +/**
> > + * struct ethtool_cmis_cdb_request - CDB commands request fields as
> decribed in
> > + *				the CMIS standard
> > + * @id: Command ID.
> > + * @epl_len: EPL memory length.
> > + * @lpl_len: LPL memory length.
> > + * @chk_code: Check code for the previous field and the payload.
> > + * @resv1: Added to match the CMIS standard request continuity.
> > + * @resv2: Added to match the CMIS standard request continuity.
> > + * @payload: Payload for the CDB commands.
> > + */
> > +struct ethtool_cmis_cdb_request {
> > +	__be16 id;
> > +	struct_group(body,
> > +		u16 epl_len;
> 
> u16 with a struct that also uses __be16 looks suspicious.
> 
> > +		u8 lpl_len;
> > +		u8 chk_code;
> > +		u8 resv1;
> > +		u8 resv2;
> > +		u8 payload[ETHTOOL_CMIS_CDB_LPL_MAX_PL_LENGTH];
> > +	);
> 
> Does it matter if the compiler inserts some padding before this struct group?

Yes it should matter since I copy this struct into a payload and it should be transferred like that to match the CMIS specification, but if I use __be16 for both id and epl_len it might resolve the issue isn’t it?

> 
> > +/**
> > + * struct ethtool_cmis_cdb_rpl_hdr - CDB commands reply header
> > +arguments
> > + * @rpl_len: Reply length.
> > + * @rpl_chk_code: Reply check code.
> > + */
> > +struct ethtool_cmis_cdb_rpl_hdr {
> > +	u8 rpl_len;
> > +	u8 rpl_chk_code;
> 
> Does it matter if the compiler adds some padding here?

Kind of the same idea, it is matter if the compiler adds padding since the reply is read and extracted into this struct like it is written in the CMIS specification.
> 
> --
> RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
> FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!
Danielle Ratson April 14, 2024, 8:20 a.m. UTC | #5
> -----Original Message-----
> From: Danielle Ratson <danieller@nvidia.com>
> Sent: Tuesday, 9 April 2024 16:34
> To: Russell King <linux@armlinux.org.uk>
> Cc: netdev@vger.kernel.org; davem@davemloft.net; edumazet@google.com;
> kuba@kernel.org; pabeni@redhat.com; corbet@lwn.net; sdf@google.com;
> kory.maincent@bootlin.com; maxime.chevallier@bootlin.com;
> vladimir.oltean@nxp.com; przemyslaw.kitszel@intel.com;
> ahmed.zaki@intel.com; richardcochran@gmail.com; shayagr@amazon.com;
> paul.greenwalt@intel.com; jiri@resnulli.us; linux-doc@vger.kernel.org; linux-
> kernel@vger.kernel.org; mlxsw <mlxsw@nvidia.com>; Petr Machata
> <petrm@nvidia.com>; Ido Schimmel <idosch@nvidia.com>
> Subject: RE: [PATCH net-next 07/10] ethtool: cmis_cdb: Add a layer for
> supporting CDB commands
> 
> > -----Original Message-----
> > From: Russell King <linux@armlinux.org.uk>
> > Sent: Monday, 8 April 2024 17:55
> > To: Danielle Ratson <danieller@nvidia.com>
> > Cc: netdev@vger.kernel.org; davem@davemloft.net;
> edumazet@google.com;
> > kuba@kernel.org; pabeni@redhat.com; corbet@lwn.net; sdf@google.com;
> > kory.maincent@bootlin.com; maxime.chevallier@bootlin.com;
> > vladimir.oltean@nxp.com; przemyslaw.kitszel@intel.com;
> > ahmed.zaki@intel.com; richardcochran@gmail.com; shayagr@amazon.com;
> > paul.greenwalt@intel.com; jiri@resnulli.us; linux-doc@vger.kernel.org;
> > linux- kernel@vger.kernel.org; mlxsw <mlxsw@nvidia.com>; Petr Machata
> > <petrm@nvidia.com>; Ido Schimmel <idosch@nvidia.com>
> > Subject: Re: [PATCH net-next 07/10] ethtool: cmis_cdb: Add a layer for
> > supporting CDB commands
> >
> > On Mon, Apr 08, 2024 at 03:53:37PM +0300, Danielle Ratson wrote:
> > > +/**
> > > + * struct ethtool_cmis_cdb_request - CDB commands request fields as
> > decribed in
> > > + *				the CMIS standard
> > > + * @id: Command ID.
> > > + * @epl_len: EPL memory length.
> > > + * @lpl_len: LPL memory length.
> > > + * @chk_code: Check code for the previous field and the payload.
> > > + * @resv1: Added to match the CMIS standard request continuity.
> > > + * @resv2: Added to match the CMIS standard request continuity.
> > > + * @payload: Payload for the CDB commands.
> > > + */
> > > +struct ethtool_cmis_cdb_request {
> > > +	__be16 id;
> > > +	struct_group(body,
> > > +		u16 epl_len;
> >
> > u16 with a struct that also uses __be16 looks suspicious.
> >
> > > +		u8 lpl_len;
> > > +		u8 chk_code;
> > > +		u8 resv1;
> > > +		u8 resv2;
> > > +		u8 payload[ETHTOOL_CMIS_CDB_LPL_MAX_PL_LENGTH];
> > > +	);
> >
> > Does it matter if the compiler inserts some padding before this struct group?
> 
> Yes it should matter since I copy this struct into a payload and it should be
> transferred like that to match the CMIS specification, but if I use __be16 for
> both id and epl_len it might resolve the issue isn’t it?
> 
> >
> > > +/**
> > > + * struct ethtool_cmis_cdb_rpl_hdr - CDB commands reply header
> > > +arguments
> > > + * @rpl_len: Reply length.
> > > + * @rpl_chk_code: Reply check code.
> > > + */
> > > +struct ethtool_cmis_cdb_rpl_hdr {
> > > +	u8 rpl_len;
> > > +	u8 rpl_chk_code;
> >
> > Does it matter if the compiler adds some padding here?
> 
> Kind of the same idea, it is matter if the compiler adds padding since the reply
> is read and extracted into this struct like it is written in the CMIS specification.
> >
> > --
> > RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
> > FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!

Hi Russell, 

Please see below pahole's output after changing ethtool_cmis_cdb_request ::epl_len from u16 to __be16.

$ pahole -C 'ethtool_cmis_cdb_request' ./vmlinux
struct ethtool_cmis_cdb_request {
        __be16                     id;                   /*     0     2 */
        union {
                struct {
                        __be16     epl_len;              /*     2     2 */
                        u8         lpl_len;              /*     4     1 */
                        u8         chk_code;             /*     5     1 */
                        u8         resv1;                /*     6     1 */
                        u8         resv2;                /*     7     1 */
                        u8         payload[120];         /*     8   120 */
                };                                       /*     2   126 */
                struct {
                        __be16     epl_len;              /*     2     2 */
                        u8         lpl_len;              /*     4     1 */
                        u8         chk_code;             /*     5     1 */
                        u8         resv1;                /*     6     1 */
                        u8         resv2;                /*     7     1 */
                        u8         payload[120];         /*     8   120 */
                } body;                                  /*     2   126 */
        };                                               /*     2   126 */

        /* size: 128, cachelines: 2, members: 2 */
};

[danieller@dev-r-vrt-155 linux_mlxsw]$ pahole -C 'ethtool_cmis_cdb_rpl' ./vmlinux
struct ethtool_cmis_cdb_rpl {
        struct ethtool_cmis_cdb_rpl_hdr hdr;             /*     0     2 */
        u8                         payload[120];         /*     2   120 */

        /* size: 122, cachelines: 2, members: 2 */
        /* last cacheline: 58 bytes */
};

[danieller@dev-r-vrt-155 linux_mlxsw]$ pahole -C 'ethtool_cmis_cdb_rpl_hdr' ./vmlinux
struct ethtool_cmis_cdb_rpl_hdr {
        u8                         rpl_len;              /*     0     1 */
        u8                         rpl_chk_code;         /*     1     1 */

        /* size: 2, cachelines: 1, members: 2 */
        /* last cacheline: 2 bytes */
};

If a further fix is needed, you are welcome to let me know.

Thanks,
Danielle
diff mbox series

Patch

diff --git a/net/ethtool/Makefile b/net/ethtool/Makefile
index 504f954a1b28..38806b3ecf83 100644
--- a/net/ethtool/Makefile
+++ b/net/ethtool/Makefile
@@ -8,4 +8,4 @@  ethtool_nl-y	:= netlink.o bitset.o strset.o linkinfo.o linkmodes.o rss.o \
 		   linkstate.o debug.o wol.o features.o privflags.o rings.o \
 		   channels.o coalesce.o pause.o eee.o tsinfo.o cabletest.o \
 		   tunnels.o fec.o eeprom.o stats.o phc_vclocks.o mm.o \
-		   module.o pse-pd.o plca.o mm.o
+		   module.o cmis_cdb.o pse-pd.o plca.o mm.o
diff --git a/net/ethtool/cmis.h b/net/ethtool/cmis.h
new file mode 100644
index 000000000000..926fc2320f07
--- /dev/null
+++ b/net/ethtool/cmis.h
@@ -0,0 +1,114 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#define ETHTOOL_CMIS_CDB_LPL_MAX_PL_LENGTH		120
+#define ETHTOOL_CMIS_CDB_CMD_PAGE			0x9F
+#define ETHTOOL_CMIS_CDB_PAGE_I2C_ADDR			0x50
+
+/**
+ * struct ethtool_cmis_cdb - CDB commands parameters
+ * @cmis_rev: CMIS revision major.
+ * @read_write_len_ext: Allowable additional number of byte octets to the LPL
+ *			in a READ or a WRITE CDB commands.
+ * @max_completion_time:  Maximum CDB command completion time in msec.
+ */
+struct ethtool_cmis_cdb {
+	u8	cmis_rev;
+	u8      read_write_len_ext;
+	u16     max_completion_time;
+};
+
+enum ethtool_cmis_cdb_cmd_id {
+	ETHTOOL_CMIS_CDB_CMD_QUERY_STATUS		= 0x0000,
+	ETHTOOL_CMIS_CDB_CMD_MODULE_FEATURES		= 0x0040,
+};
+
+/**
+ * struct ethtool_cmis_cdb_request - CDB commands request fields as decribed in
+ *				the CMIS standard
+ * @id: Command ID.
+ * @epl_len: EPL memory length.
+ * @lpl_len: LPL memory length.
+ * @chk_code: Check code for the previous field and the payload.
+ * @resv1: Added to match the CMIS standard request continuity.
+ * @resv2: Added to match the CMIS standard request continuity.
+ * @payload: Payload for the CDB commands.
+ */
+struct ethtool_cmis_cdb_request {
+	__be16 id;
+	struct_group(body,
+		u16 epl_len;
+		u8 lpl_len;
+		u8 chk_code;
+		u8 resv1;
+		u8 resv2;
+		u8 payload[ETHTOOL_CMIS_CDB_LPL_MAX_PL_LENGTH];
+	);
+};
+
+#define CDB_F_COMPLETION_VALID		BIT(0)
+#define CDB_F_STATUS_VALID		BIT(1)
+
+/**
+ * struct ethtool_cmis_cdb_cmd_args - CDB commands execution arguments
+ * @req: CDB command fields as described in the CMIS standard.
+ * @max_duration: Maximum duration time for command completion in msec.
+ * @read_write_len_ext: Allowable additional number of byte octets to the LPL
+ *			in a READ or a WRITE commands.
+ * @rpl_exp_len: Expected reply length in bytes.
+ * @flags: Validation flags for CDB commands.
+ */
+struct ethtool_cmis_cdb_cmd_args {
+	struct ethtool_cmis_cdb_request req;
+	u16				max_duration;
+	u8				read_write_len_ext;
+	u8				msleep_pre_rpl;
+	u8                              rpl_exp_len;
+	u8				flags;
+	char				*err_msg;
+};
+
+/**
+ * struct ethtool_cmis_cdb_rpl_hdr - CDB commands reply header arguments
+ * @rpl_len: Reply length.
+ * @rpl_chk_code: Reply check code.
+ */
+struct ethtool_cmis_cdb_rpl_hdr {
+	u8 rpl_len;
+	u8 rpl_chk_code;
+};
+
+/**
+ * struct ethtool_cmis_cdb_rpl - CDB commands reply arguments
+ * @hdr: CDB commands reply header arguments.
+ * @payload: Payload for the CDB commands reply.
+ */
+struct ethtool_cmis_cdb_rpl {
+	struct ethtool_cmis_cdb_rpl_hdr hdr;
+	u8 payload[ETHTOOL_CMIS_CDB_LPL_MAX_PL_LENGTH];
+};
+
+u32 ethtool_cmis_get_max_payload_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);
+
+void ethtool_cmis_cdb_check_completion_flag(u8 cmis_rev, u8 *flags);
+
+void ethtool_cmis_page_init(struct ethtool_module_eeprom *page_data,
+			    u8 page, u32 offset, u32 length);
+void ethtool_cmis_page_fini(struct ethtool_module_eeprom *page_data);
+
+struct ethtool_cmis_cdb *
+ethtool_cmis_cdb_init(struct net_device *dev,
+		      const struct ethtool_module_fw_flash_params *params);
+void ethtool_cmis_cdb_fini(struct ethtool_cmis_cdb *cdb);
+
+int ethtool_cmis_wait_for_cond(struct net_device *dev, u8 flags, u8 flag,
+			       u16 max_duration, u32 offset,
+			       bool (*cond_success)(u8), bool (*cond_fail)(u8));
+
+int ethtool_cmis_cdb_execute_cmd(struct net_device *dev,
+				 struct ethtool_cmis_cdb_cmd_args *args);
diff --git a/net/ethtool/cmis_cdb.c b/net/ethtool/cmis_cdb.c
new file mode 100644
index 000000000000..992d59c51299
--- /dev/null
+++ b/net/ethtool/cmis_cdb.c
@@ -0,0 +1,549 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/ethtool.h>
+#include <linux/jiffies.h>
+
+#include "common.h"
+#include "module_fw.h"
+#include "cmis.h"
+
+/* For accessing the LPL field on page 9Fh, the allowable length extension is
+ * 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)
+{
+	return 8 * (1 + min_t(u8, num_of_byte_octs, 15));
+}
+
+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)
+{
+	args->req.id = cpu_to_be16(cmd);
+	args->req.lpl_len = lpl_len;
+	if (pl)
+		memcpy(args->req.payload, pl, args->req.lpl_len);
+
+	args->max_duration = max_duration;
+	args->read_write_len_ext =
+		ethtool_cmis_get_max_payload_size(read_write_len_ext);
+	args->msleep_pre_rpl = msleep_pre_rpl;
+	args->rpl_exp_len = rpl_exp_len;
+	args->flags = flags;
+	args->err_msg = NULL;
+}
+
+void ethtool_cmis_page_init(struct ethtool_module_eeprom *page_data,
+			    u8 page, u32 offset, u32 length)
+{
+	page_data->page = page;
+	page_data->offset = offset;
+	page_data->length = length;
+	page_data->i2c_address = ETHTOOL_CMIS_CDB_PAGE_I2C_ADDR;
+}
+
+#define CMIS_REVISION_PAGE	0x00
+#define CMIS_REVISION_OFFSET	0x01
+
+struct cmis_rev_rpl {
+	u8 rev;
+};
+
+static inline u8
+cmis_rev_rpl_major(struct cmis_rev_rpl *rpl)
+{
+	return rpl->rev >> 4;
+}
+
+static int cmis_rev_major_get(struct net_device *dev, u8 *rev_major)
+{
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct ethtool_module_eeprom page_data = {0};
+	struct netlink_ext_ack extack = {};
+	struct cmis_rev_rpl rpl = {};
+	int err;
+
+	ethtool_cmis_page_init(&page_data, CMIS_REVISION_PAGE,
+			       CMIS_REVISION_OFFSET, sizeof(rpl));
+	page_data.data = (u8 *)&rpl;
+
+	err = ops->get_module_eeprom_by_page(dev, &page_data, &extack);
+	if (err < 0) {
+		if (extack._msg)
+			netdev_err(dev, "%s\n", extack._msg);
+		return err;
+	}
+
+	*rev_major = cmis_rev_rpl_major(&rpl);
+
+	return 0;
+}
+
+#define CMIS_CDB_ADVERTISEMENT_PAGE	0x01
+#define CMIS_CDB_ADVERTISEMENT_OFFSET	0xA3
+
+/* Based on section 8.4.11 "CDB Messaging Support Advertisement" in CMIS
+ * standard revision 5.2.
+ */
+struct cmis_cdb_advert_rpl {
+	u8	inst_supported;
+	u8	read_write_len_ext;
+	u8	resv1;
+	u8	resv2;
+};
+
+static inline u8
+cmis_cdb_advert_rpl_inst_supported(struct cmis_cdb_advert_rpl *rpl)
+{
+	return rpl->inst_supported >> 6;
+}
+
+static int cmis_cdb_advertisement_get(struct ethtool_cmis_cdb *cdb,
+				      struct net_device *dev)
+{
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct ethtool_module_eeprom page_data = {};
+	struct cmis_cdb_advert_rpl rpl = {};
+	struct netlink_ext_ack extack = {};
+	int err;
+
+	ethtool_cmis_page_init(&page_data, CMIS_CDB_ADVERTISEMENT_PAGE,
+			       CMIS_CDB_ADVERTISEMENT_OFFSET, sizeof(rpl));
+	page_data.data = (u8 *)&rpl;
+
+	err = ops->get_module_eeprom_by_page(dev, &page_data, &extack);
+	if (err < 0) {
+		if (extack._msg)
+			netdev_err(dev, "%s\n", extack._msg);
+		return err;
+	}
+
+	if (!cmis_cdb_advert_rpl_inst_supported(&rpl))
+		return -EOPNOTSUPP;
+
+	cdb->read_write_len_ext = rpl.read_write_len_ext;
+
+	return 0;
+}
+
+#define CMIS_PASSWORD_ENTRY_PAGE	0x00
+#define CMIS_PASSWORD_ENTRY_OFFSET	0x7A
+
+struct cmis_password_entry_pl {
+	__be32 password;
+};
+
+/* See section 9.3.1 "CMD 0000h: Query Status" in CMIS standard revision 5.2.
+ * struct cmis_cdb_query_status_pl and struct cmis_cdb_query_status_rpl are
+ * structured layouts of the flat arrays,
+ * struct ethtool_cmis_cdb_request::payload and
+ * struct ethtool_cmis_cdb_rpl::payload respectively.
+ */
+struct cmis_cdb_query_status_pl {
+	u16 response_delay;
+};
+
+struct cmis_cdb_query_status_rpl {
+	u8 length;
+	u8 status;
+};
+
+static int
+cmis_cdb_validate_password(struct ethtool_cmis_cdb *cdb,
+			   struct net_device *dev,
+			   const struct ethtool_module_fw_flash_params *params)
+{
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct cmis_cdb_query_status_pl qs_pl = {0};
+	struct ethtool_module_eeprom page_data = {};
+	struct ethtool_cmis_cdb_cmd_args args = {};
+	struct cmis_password_entry_pl pe_pl = {};
+	struct cmis_cdb_query_status_rpl *rpl;
+	struct netlink_ext_ack extack = {};
+	int err;
+
+	ethtool_cmis_page_init(&page_data, CMIS_PASSWORD_ENTRY_PAGE,
+			       CMIS_PASSWORD_ENTRY_OFFSET, sizeof(pe_pl));
+	page_data.data = (u8 *)&pe_pl;
+
+	pe_pl = *((struct cmis_password_entry_pl *)page_data.data);
+	pe_pl.password = params->password;
+	err = ops->set_module_eeprom_by_page(dev, &page_data, &extack);
+	if (err < 0) {
+		if (extack._msg)
+			netdev_err(dev, "%s\n", extack._msg);
+		return err;
+	}
+
+	ethtool_cmis_cdb_compose_args(&args, ETHTOOL_CMIS_CDB_CMD_QUERY_STATUS,
+				      (u8 *)&qs_pl, sizeof(qs_pl), 0,
+				      cdb->read_write_len_ext, 1000,
+				      sizeof(*rpl),
+				      CDB_F_COMPLETION_VALID | CDB_F_STATUS_VALID);
+
+	err = ethtool_cmis_cdb_execute_cmd(dev, &args);
+	if (err < 0) {
+		ethnl_module_fw_flash_ntf_err(dev,
+					      "Query Status command failed",
+					      args.err_msg);
+		return err;
+	}
+
+	rpl = (struct cmis_cdb_query_status_rpl *)args.req.payload;
+	if (!rpl->length || !rpl->status) {
+		ethnl_module_fw_flash_ntf_err(dev, "Password was not accepted",
+					      NULL);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/* Some CDB commands asserts the CDB completion flag only from CMIS
+ * revision 5. Therefore, check the relevant validity flag only when
+ * the revision supports it.
+ */
+inline void ethtool_cmis_cdb_check_completion_flag(u8 cmis_rev, u8 *flags)
+{
+	*flags |= cmis_rev >= 5 ? CDB_F_COMPLETION_VALID : 0;
+}
+
+#define CMIS_CDB_MODULE_FEATURES_RESV_DATA	34
+
+/* See section 9.4.1 "CMD 0040h: Module Features" in CMIS standard revision 5.2.
+ * struct cmis_cdb_module_features_rpl is structured layout of the flat
+ * array, ethtool_cmis_cdb_rpl::payload.
+ */
+struct cmis_cdb_module_features_rpl {
+	u8	resv1[CMIS_CDB_MODULE_FEATURES_RESV_DATA];
+	__be16	max_completion_time;
+};
+
+static inline u16
+cmis_cdb_module_features_completion_time(struct cmis_cdb_module_features_rpl *rpl)
+{
+	return be16_to_cpu(rpl->max_completion_time);
+}
+
+static int cmis_cdb_module_features_get(struct ethtool_cmis_cdb *cdb,
+					struct net_device *dev)
+{
+	struct ethtool_cmis_cdb_cmd_args args = {};
+	struct cmis_cdb_module_features_rpl *rpl;
+	u8 flags = CDB_F_STATUS_VALID;
+	int err;
+
+	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);
+
+	err = ethtool_cmis_cdb_execute_cmd(dev, &args);
+	if (err < 0) {
+		ethnl_module_fw_flash_ntf_err(dev,
+					      "Module Features command failed",
+					      args.err_msg);
+		return err;
+	}
+
+	rpl = (struct cmis_cdb_module_features_rpl *)args.req.payload;
+	cdb->max_completion_time =
+		cmis_cdb_module_features_completion_time(rpl);
+
+	return 0;
+}
+
+struct ethtool_cmis_cdb *
+ethtool_cmis_cdb_init(struct net_device *dev,
+		      const struct ethtool_module_fw_flash_params *params)
+{
+	struct ethtool_cmis_cdb *cdb;
+	int err;
+
+	cdb = kzalloc(sizeof(*cdb), GFP_KERNEL);
+	if (!cdb)
+		return ERR_PTR(-ENOMEM);
+
+	err = cmis_rev_major_get(dev, &cdb->cmis_rev);
+	if (err < 0)
+		goto err;
+
+	if (cdb->cmis_rev < 4) {
+		ethnl_module_fw_flash_ntf_err(dev,
+					      "CMIS revision doesn't support module firmware flashing",
+					      NULL);
+		err = -EOPNOTSUPP;
+		goto err;
+	}
+
+	err = cmis_cdb_advertisement_get(cdb, dev);
+	if (err < 0)
+		goto err;
+
+	if (params->password_valid) {
+		err = cmis_cdb_validate_password(cdb, dev, params);
+		if (err < 0)
+			goto err;
+	}
+
+	err = cmis_cdb_module_features_get(cdb, dev);
+	if (err < 0)
+		goto err;
+
+	return cdb;
+
+err:
+	ethtool_cmis_cdb_fini(cdb);
+	return ERR_PTR(err);
+}
+
+void ethtool_cmis_cdb_fini(struct ethtool_cmis_cdb *cdb)
+{
+	kfree(cdb);
+}
+
+static bool is_completed(u8 data)
+{
+	return !!(data & 0x40);
+}
+
+#define CMIS_CDB_STATUS_SUCCESS	0x01
+
+static bool status_success(u8 data)
+{
+	return data == CMIS_CDB_STATUS_SUCCESS;
+}
+
+#define CMIS_CDB_STATUS_FAIL	0x40
+
+static bool status_fail(u8 data)
+{
+	return data & CMIS_CDB_STATUS_FAIL;
+}
+
+struct cmis_wait_for_cond_rpl {
+	u8 state;
+};
+
+int ethtool_cmis_wait_for_cond(struct net_device *dev, u8 flags, u8 flag,
+			       u16 max_duration, u32 offset,
+			       bool (*cond_success)(u8), bool (*cond_fail)(u8))
+{
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct ethtool_module_eeprom page_data = {0};
+	struct cmis_wait_for_cond_rpl rpl = {};
+	struct netlink_ext_ack extack = {};
+	unsigned long end;
+	int err;
+
+	if (!(flags & flag))
+		return 0;
+
+	if (max_duration == 0)
+		max_duration = U16_MAX;
+
+	end = jiffies + msecs_to_jiffies(max_duration);
+	do {
+		ethtool_cmis_page_init(&page_data, 0, offset, sizeof(rpl));
+		page_data.data = (u8 *)&rpl;
+
+		err = ops->get_module_eeprom_by_page(dev, &page_data, &extack);
+		if (err < 0) {
+			if (extack._msg)
+				netdev_err(dev, "%s\n", extack._msg);
+			continue;
+		}
+
+		if ((*cond_success)(rpl.state))
+			return 0;
+
+		if (*cond_fail && (*cond_fail)(rpl.state))
+			break;
+
+		msleep(20);
+	} while (time_before(jiffies, end));
+
+	return -EBUSY;
+}
+
+#define CMIS_CDB_COMPLETION_FLAG_OFFSET	0x08
+
+static int cmis_cdb_wait_for_completion(struct net_device *dev,
+					struct ethtool_cmis_cdb_cmd_args *args)
+{
+	int err;
+
+	/* Some vendors demand waiting time before checking completion flag
+	 * in some CDB commands.
+	 */
+	msleep(args->msleep_pre_rpl);
+
+	err = ethtool_cmis_wait_for_cond(dev, args->flags,
+					 CDB_F_COMPLETION_VALID,
+					 args->max_duration,
+					 CMIS_CDB_COMPLETION_FLAG_OFFSET,
+					 is_completed, NULL);
+	if (err < 0)
+		args->err_msg = "Completion Flag did not set on time";
+
+	return err;
+}
+
+#define CMIS_CDB_STATUS_OFFSET	0x25
+
+static int cmis_cdb_wait_for_status(struct net_device *dev,
+				    struct ethtool_cmis_cdb_cmd_args *args)
+{
+	int err;
+
+	/* Some vendors demand waiting time before checking status in some
+	 * CDB commands.
+	 */
+	msleep(args->msleep_pre_rpl);
+
+	err = ethtool_cmis_wait_for_cond(dev, args->flags, CDB_F_STATUS_VALID,
+					 args->max_duration,
+					 CMIS_CDB_STATUS_OFFSET,
+					 status_success, status_fail);
+	if (err < 0)
+		args->err_msg = "CDB Status did not succeed on time";
+
+	return err;
+}
+
+#define CMIS_CDB_REPLY_OFFSET	0x86
+
+static int cmis_cdb_process_reply(struct net_device *dev,
+				  struct ethtool_module_eeprom *page_data,
+				  struct ethtool_cmis_cdb_cmd_args *args)
+{
+	u8 rpl_hdr_len = sizeof(struct ethtool_cmis_cdb_rpl_hdr);
+	u8 rpl_exp_len = args->rpl_exp_len + rpl_hdr_len;
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct netlink_ext_ack extack = {};
+	struct ethtool_cmis_cdb_rpl *rpl;
+	int err;
+
+	if (!args->rpl_exp_len)
+		return 0;
+
+	ethtool_cmis_page_init(page_data, ETHTOOL_CMIS_CDB_CMD_PAGE,
+			       CMIS_CDB_REPLY_OFFSET, rpl_exp_len);
+	page_data->data = kmalloc(page_data->length, GFP_KERNEL);
+	if (!page_data->data)
+		return -ENOMEM;
+
+	err = ops->get_module_eeprom_by_page(dev, page_data, &extack);
+	if (err < 0) {
+		if (extack._msg)
+			netdev_err(dev, "%s\n", extack._msg);
+		goto out;
+	}
+
+	rpl = (struct ethtool_cmis_cdb_rpl *)page_data->data;
+	if ((args->rpl_exp_len > rpl->hdr.rpl_len + rpl_hdr_len) ||
+	    !rpl->hdr.rpl_chk_code) {
+		err = -EIO;
+		goto out;
+	}
+
+	args->req.lpl_len = rpl->hdr.rpl_len;
+	memcpy(args->req.payload, rpl->payload, args->req.lpl_len);
+
+out:
+	kfree(page_data->data);
+	return err;
+}
+
+static int
+__ethtool_cmis_cdb_execute_cmd(struct net_device *dev,
+			       struct ethtool_module_eeprom *page_data,
+			       u8 page, u32 offset, u32 length, void *data)
+{
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct netlink_ext_ack extack = {};
+	int err;
+
+	ethtool_cmis_page_init(page_data, page, offset, length);
+	page_data->data = kmalloc(page_data->length, GFP_KERNEL);
+	if (!page_data->data)
+		return -ENOMEM;
+
+	memcpy(page_data->data, data, page_data->length);
+
+	err = ops->set_module_eeprom_by_page(dev, page_data, &extack);
+	if (err < 0) {
+		if (extack._msg)
+			netdev_err(dev, "%s\n", extack._msg);
+	}
+
+	kfree(page_data->data);
+	return err;
+}
+
+static u8 cmis_cdb_calc_checksum(const void *data, size_t size)
+{
+	const u8 *bytes = (const u8 *)data;
+	u8 checksum = 0;
+
+	for (size_t i = 0; i < size; i++)
+		checksum += bytes[i];
+
+	return ~checksum;
+}
+
+#define CMIS_CDB_CMD_ID_OFFSET	0x80
+
+int ethtool_cmis_cdb_execute_cmd(struct net_device *dev,
+				 struct ethtool_cmis_cdb_cmd_args *args)
+{
+	struct ethtool_module_eeprom page_data = {};
+	u32 offset;
+	int err;
+
+	args->req.chk_code =
+		cmis_cdb_calc_checksum(&args->req, sizeof(args->req));
+
+	if (args->req.lpl_len > args->read_write_len_ext) {
+		args->err_msg = "LPL length is longer than CDB read write length extension allows";
+		return -EINVAL;
+	}
+
+	/* According to the CMIS standard, there are two options to trigger the
+	 * CDB commands. The default option is triggering the command by writing
+	 * the CMDID bytes. Therefore, the command will be split to 2 calls:
+	 * First, with everything except the CMDID field and then the CMDID
+	 * field.
+	 */
+	offset = CMIS_CDB_CMD_ID_OFFSET +
+		offsetof(struct ethtool_cmis_cdb_request, body);
+	err = __ethtool_cmis_cdb_execute_cmd(dev, &page_data,
+					     ETHTOOL_CMIS_CDB_CMD_PAGE, offset,
+					     sizeof(args->req.body),
+					     &args->req.body);
+	if (err < 0)
+		return err;
+
+	offset = CMIS_CDB_CMD_ID_OFFSET +
+		offsetof(struct ethtool_cmis_cdb_request, id);
+	err = __ethtool_cmis_cdb_execute_cmd(dev, &page_data,
+					     ETHTOOL_CMIS_CDB_CMD_PAGE, offset,
+					     sizeof(args->req.id),
+					     &args->req.id);
+	if (err < 0)
+		return err;
+
+	err = cmis_cdb_wait_for_completion(dev, args);
+	if (err < 0)
+		return err;
+
+	err = cmis_cdb_wait_for_status(dev, args);
+	if (err < 0)
+		return err;
+
+	return cmis_cdb_process_reply(dev, &page_data, args);
+}
diff --git a/net/ethtool/module_fw.h b/net/ethtool/module_fw.h
index e40eae442741..96da7a8175f2 100644
--- a/net/ethtool/module_fw.h
+++ b/net/ethtool/module_fw.h
@@ -8,3 +8,13 @@  void ethnl_module_fw_flash_ntf_start(struct net_device *dev);
 void ethnl_module_fw_flash_ntf_complete(struct net_device *dev);
 void ethnl_module_fw_flash_ntf_in_progress(struct net_device *dev, u64 done,
 					   u64 total);
+
+/**
+ * struct ethtool_module_fw_flash_params - module firmware flashing parameters
+ * @password: Module password. Only valid when @pass_valid is set.
+ * @password_valid: Whether the module password is valid or not.
+ */
+struct ethtool_module_fw_flash_params {
+	__be32 password;
+	u8 password_valid:1;
+};