From: Vladyslav Tarasiuk <vladysl...@nvidia.com>

Define get_module_eeprom_data_by_page() ethtool callback and implement
netlink infrastructure.

get_module_eeprom_data_by_page() allows network drivers to dump a part
of module's EEPROM specified by page and bank numbers along with offset
and length. It is effectively a netlink replacement for
get_module_info() and get_module_eeprom() pair, which is needed due to
emergence of complex non-linear EEPROM layouts.

Signed-off-by: Vladyslav Tarasiuk <vladysl...@nvidia.com>
---
 include/linux/ethtool.h              |   7 +-
 include/uapi/linux/ethtool.h         |  26 +++++
 include/uapi/linux/ethtool_netlink.h |  19 ++++
 net/ethtool/Makefile                 |   2 +-
 net/ethtool/eeprom.c                 | 157 +++++++++++++++++++++++++++
 net/ethtool/netlink.c                |  10 ++
 net/ethtool/netlink.h                |   2 +
 7 files changed, 221 insertions(+), 2 deletions(-)
 create mode 100644 net/ethtool/eeprom.c

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index ec4cd3921c67..2f65aae5f492 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -81,6 +81,7 @@ enum {
 #define ETH_RSS_HASH_NO_CHANGE 0
 
 struct net_device;
+struct netlink_ext_ack;
 
 /* Some generic methods drivers may use in their ethtool_ops */
 u32 ethtool_op_get_link(struct net_device *dev);
@@ -410,6 +411,8 @@ struct ethtool_pause_stats {
  * @get_ethtool_phy_stats: Return extended statistics about the PHY device.
  *     This is only useful if the device maintains PHY statistics and
  *     cannot use the standard PHY library helpers.
+ * @get_module_eeprom_data_by_page: Get a region of plug-in module EEPROM data
+ *     from specified page. Returns a negative error code or zero.
  *
  * All operations are optional (i.e. the function pointer may be set
  * to %NULL) and callers must take this into account.  Callers must
@@ -515,6 +518,9 @@ struct ethtool_ops {
                                   const struct ethtool_tunable *, void *);
        int     (*set_phy_tunable)(struct net_device *,
                                   const struct ethtool_tunable *, const void 
*);
+       int     (*get_module_eeprom_data_by_page)(struct net_device *dev,
+                                                 const struct 
ethtool_eeprom_data *page,
+                                                 struct netlink_ext_ack 
*extack);
 };
 
 int ethtool_check_ops(const struct ethtool_ops *ops);
@@ -538,7 +544,6 @@ int ethtool_virtdev_set_link_ksettings(struct net_device 
*dev,
                                       const struct ethtool_link_ksettings *cmd,
                                       u32 *dev_speed, u8 *dev_duplex);
 
-struct netlink_ext_ack;
 struct phy_device;
 struct phy_tdr_config;
 
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index cde753bb2093..2459571fc1d1 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -340,6 +340,28 @@ struct ethtool_eeprom {
        __u8    data[0];
 };
 
+/**
+ * struct ethtool_eeprom_data - EEPROM dump from specified page
+ * @offset: Offset within the specified EEPROM page to begin read, in bytes.
+ * @length: Number of bytes to read.
+ * @page: Page number to read from.
+ * @bank: Page bank number to read from, if applicable by EEPROM spec.
+ * @i2c_address: I2C address of a page. Value less than 0x7f expected. Most
+ *     EEPROMs use 0x50 or 0x51.
+ * @data: Pointer to buffer with EEPROM data of @length size.
+ *
+ * This can be used to manage pages during EEPROM dump in ethtool and pass
+ * required information to the driver.
+ */
+struct ethtool_eeprom_data {
+       __u32   offset;
+       __u32   length;
+       __u32   page;
+       __u32   bank;
+       __u32   i2c_address;
+       __u8    *data;
+};
+
 /**
  * struct ethtool_eee - Energy Efficient Ethernet information
  * @cmd: ETHTOOL_{G,S}EEE
@@ -1865,6 +1887,10 @@ static inline int ethtool_validate_duplex(__u8 duplex)
 #define ETH_MODULE_SFF_8636_MAX_LEN     640
 #define ETH_MODULE_SFF_8436_MAX_LEN     640
 
+#define ETH_MODULE_EEPROM_MAX_LEN      640
+#define ETH_MODULE_EEPROM_PAGE_LEN     256
+#define ETH_MODULE_MAX_I2C_ADDRESS     0x7f
+
 /* Reset flags */
 /* The reset() operation must clear the flags for the components which
  * were actually reset.  On successful return, the flags indicate the
diff --git a/include/uapi/linux/ethtool_netlink.h 
b/include/uapi/linux/ethtool_netlink.h
index a286635ac9b8..60dd848d0b54 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -42,6 +42,7 @@ enum {
        ETHTOOL_MSG_CABLE_TEST_ACT,
        ETHTOOL_MSG_CABLE_TEST_TDR_ACT,
        ETHTOOL_MSG_TUNNEL_INFO_GET,
+       ETHTOOL_MSG_EEPROM_DATA_GET,
 
        /* add new constants above here */
        __ETHTOOL_MSG_USER_CNT,
@@ -80,6 +81,7 @@ enum {
        ETHTOOL_MSG_CABLE_TEST_NTF,
        ETHTOOL_MSG_CABLE_TEST_TDR_NTF,
        ETHTOOL_MSG_TUNNEL_INFO_GET_REPLY,
+       ETHTOOL_MSG_EEPROM_DATA_GET_REPLY,
 
        /* add new constants above here */
        __ETHTOOL_MSG_KERNEL_CNT,
@@ -629,6 +631,23 @@ enum {
        ETHTOOL_A_TUNNEL_INFO_MAX = (__ETHTOOL_A_TUNNEL_INFO_CNT - 1)
 };
 
+/* MODULE EEPROM DATA */
+
+enum {
+       ETHTOOL_A_EEPROM_DATA_UNSPEC,
+       ETHTOOL_A_EEPROM_DATA_HEADER,
+
+       ETHTOOL_A_EEPROM_DATA_OFFSET,
+       ETHTOOL_A_EEPROM_DATA_LENGTH,
+       ETHTOOL_A_EEPROM_DATA_PAGE,
+       ETHTOOL_A_EEPROM_DATA_BANK,
+       ETHTOOL_A_EEPROM_DATA_I2C_ADDRESS,
+       ETHTOOL_A_EEPROM_DATA,
+
+       __ETHTOOL_A_EEPROM_DATA_CNT,
+       ETHTOOL_A_EEPROM_DATA_MAX = (__ETHTOOL_A_EEPROM_DATA_CNT - 1)
+};
+
 /* generic netlink info */
 #define ETHTOOL_GENL_NAME "ethtool"
 #define ETHTOOL_GENL_VERSION 1
diff --git a/net/ethtool/Makefile b/net/ethtool/Makefile
index 7a849ff22dad..d604346bc074 100644
--- a/net/ethtool/Makefile
+++ b/net/ethtool/Makefile
@@ -7,4 +7,4 @@ obj-$(CONFIG_ETHTOOL_NETLINK)   += ethtool_nl.o
 ethtool_nl-y   := netlink.o bitset.o strset.o linkinfo.o linkmodes.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
+                  tunnels.o eeprom.o
diff --git a/net/ethtool/eeprom.c b/net/ethtool/eeprom.c
new file mode 100644
index 000000000000..2618a55b9a40
--- /dev/null
+++ b/net/ethtool/eeprom.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/ethtool.h>
+#include "netlink.h"
+#include "common.h"
+
+struct eeprom_data_req_info {
+       struct ethnl_req_info   base;
+       u32                     offset;
+       u32                     length;
+       u32                     page;
+       u32                     bank;
+       u32                     i2c_address;
+};
+
+struct eeprom_data_reply_data {
+       struct ethnl_reply_data base;
+       u32                     length;
+       u32                     i2c_address;
+       u8                      *data;
+};
+
+#define EEPROM_DATA_REQINFO(__req_base) \
+       container_of(__req_base, struct eeprom_data_req_info, base)
+
+#define EEPROM_DATA_REPDATA(__reply_base) \
+       container_of(__reply_base, struct eeprom_data_reply_data, base)
+
+static int eeprom_data_prepare_data(const struct ethnl_req_info *req_base,
+                                   struct ethnl_reply_data *reply_base,
+                                   struct genl_info *info)
+{
+       struct eeprom_data_reply_data *reply = EEPROM_DATA_REPDATA(reply_base);
+       struct eeprom_data_req_info *request = EEPROM_DATA_REQINFO(req_base);
+       struct ethtool_eeprom_data page_data = {0};
+       struct net_device *dev = reply_base->dev;
+       int err;
+
+       if (!dev->ethtool_ops->get_module_eeprom_data_by_page)
+               return -EOPNOTSUPP;
+
+       page_data.offset = request->offset;
+       page_data.length = request->length;
+       page_data.i2c_address = request->i2c_address;
+       page_data.page = request->page;
+       page_data.bank = request->bank;
+       page_data.data = kmalloc(page_data.length, GFP_KERNEL);
+       if (!page_data.data)
+               return -ENOMEM;
+       err = ethnl_ops_begin(dev);
+       if (err)
+               goto err_free;
+
+       err = dev->ethtool_ops->get_module_eeprom_data_by_page(dev, &page_data,
+                                                              info->extack);
+       if (err)
+               goto err_ops;
+
+       reply->length = page_data.length;
+       reply->i2c_address = page_data.i2c_address;
+       reply->data = page_data.data;
+
+       ethnl_ops_complete(dev);
+       return 0;
+
+err_ops:
+       ethnl_ops_complete(dev);
+err_free:
+       kfree(page_data.data);
+       return err;
+}
+
+static int eeprom_data_parse_request(struct ethnl_req_info *req_info, struct 
nlattr **tb,
+                                    struct netlink_ext_ack *extack)
+{
+       struct eeprom_data_req_info *request = EEPROM_DATA_REQINFO(req_info);
+
+       if (!tb[ETHTOOL_A_EEPROM_DATA_OFFSET] ||
+           !tb[ETHTOOL_A_EEPROM_DATA_LENGTH] ||
+           !tb[ETHTOOL_A_EEPROM_DATA_I2C_ADDRESS])
+               return -EINVAL;
+
+       request->i2c_address = 
nla_get_u32(tb[ETHTOOL_A_EEPROM_DATA_I2C_ADDRESS]);
+       if (request->i2c_address > ETH_MODULE_MAX_I2C_ADDRESS)
+               return -EINVAL;
+
+       request->offset = nla_get_u32(tb[ETHTOOL_A_EEPROM_DATA_OFFSET]);
+       request->length = nla_get_u32(tb[ETHTOOL_A_EEPROM_DATA_LENGTH]);
+       if (request->length > ETH_MODULE_EEPROM_MAX_LEN)
+               return -EINVAL;
+       if (tb[ETHTOOL_A_EEPROM_DATA_PAGE] &&
+           request->offset + request->length > ETH_MODULE_EEPROM_PAGE_LEN)
+               return -EINVAL;
+
+       if (tb[ETHTOOL_A_EEPROM_DATA_PAGE])
+               request->page = nla_get_u32(tb[ETHTOOL_A_EEPROM_DATA_PAGE]);
+       if (tb[ETHTOOL_A_EEPROM_DATA_BANK])
+               request->bank = nla_get_u32(tb[ETHTOOL_A_EEPROM_DATA_BANK]);
+
+       return 0;
+}
+
+static int eeprom_data_reply_size(const struct ethnl_req_info *req_base,
+                                 const struct ethnl_reply_data *reply_base)
+{
+       const struct eeprom_data_req_info *request = 
EEPROM_DATA_REQINFO(req_base);
+
+       return nla_total_size(sizeof(u32)) + /* _EEPROM_DATA_LENGTH */
+              nla_total_size(sizeof(u32)) + /* _EEPROM_DATA_I2C_ADDRESS */
+              nla_total_size(sizeof(u8) * request->length); /* _EEPROM_DATA */
+}
+
+static int eeprom_data_fill_reply(struct sk_buff *skb,
+                                 const struct ethnl_req_info *req_base,
+                                 const struct ethnl_reply_data *reply_base)
+{
+       struct eeprom_data_reply_data *reply = EEPROM_DATA_REPDATA(reply_base);
+
+       if (nla_put_u32(skb, ETHTOOL_A_EEPROM_DATA_LENGTH, reply->length) ||
+           nla_put_u32(skb, ETHTOOL_A_EEPROM_DATA_I2C_ADDRESS, 
reply->i2c_address) ||
+           nla_put(skb, ETHTOOL_A_EEPROM_DATA, reply->length, reply->data))
+               return -EMSGSIZE;
+
+       return 0;
+}
+
+static void eeprom_data_cleanup_data(struct ethnl_reply_data *reply_base)
+{
+       struct eeprom_data_reply_data *reply = EEPROM_DATA_REPDATA(reply_base);
+
+       kfree(reply->data);
+}
+
+const struct ethnl_request_ops ethnl_eeprom_data_request_ops = {
+       .request_cmd            = ETHTOOL_MSG_EEPROM_DATA_GET,
+       .reply_cmd              = ETHTOOL_MSG_EEPROM_DATA_GET_REPLY,
+       .hdr_attr               = ETHTOOL_A_EEPROM_DATA_HEADER,
+       .req_info_size          = sizeof(struct eeprom_data_req_info),
+       .reply_data_size        = sizeof(struct eeprom_data_reply_data),
+
+       .parse_request          = eeprom_data_parse_request,
+       .prepare_data           = eeprom_data_prepare_data,
+       .reply_size             = eeprom_data_reply_size,
+       .fill_reply             = eeprom_data_fill_reply,
+       .cleanup_data           = eeprom_data_cleanup_data,
+};
+
+const struct nla_policy ethnl_eeprom_data_get_policy[] = {
+       [ETHTOOL_A_EEPROM_DATA_HEADER]          = 
NLA_POLICY_NESTED(ethnl_header_policy),
+       [ETHTOOL_A_EEPROM_DATA_OFFSET]          = { .type = NLA_U32 },
+       [ETHTOOL_A_EEPROM_DATA_LENGTH]          = { .type = NLA_U32 },
+       [ETHTOOL_A_EEPROM_DATA_PAGE]            = { .type = NLA_U32 },
+       [ETHTOOL_A_EEPROM_DATA_BANK]            = { .type = NLA_U32 },
+       [ETHTOOL_A_EEPROM_DATA_I2C_ADDRESS]     = { .type = NLA_U32 },
+       [ETHTOOL_A_EEPROM_DATA]                 = { .type = NLA_BINARY },
+};
+
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 50d3c8896f91..ff2528bee192 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -245,6 +245,7 @@ ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
        [ETHTOOL_MSG_PAUSE_GET]         = &ethnl_pause_request_ops,
        [ETHTOOL_MSG_EEE_GET]           = &ethnl_eee_request_ops,
        [ETHTOOL_MSG_TSINFO_GET]        = &ethnl_tsinfo_request_ops,
+       [ETHTOOL_MSG_EEPROM_DATA_GET]   = &ethnl_eeprom_data_request_ops,
 };
 
 static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
@@ -912,6 +913,15 @@ static const struct genl_ops ethtool_genl_ops[] = {
                .policy = ethnl_tunnel_info_get_policy,
                .maxattr = ARRAY_SIZE(ethnl_tunnel_info_get_policy) - 1,
        },
+       {
+               .cmd    = ETHTOOL_MSG_EEPROM_DATA_GET,
+               .doit   = ethnl_default_doit,
+               .start  = ethnl_default_start,
+               .dumpit = ethnl_default_dumpit,
+               .done   = ethnl_default_done,
+               .policy = ethnl_eeprom_data_get_policy,
+               .maxattr = ARRAY_SIZE(ethnl_eeprom_data_get_policy) - 1,
+       },
 };
 
 static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index 6eabd58d81bf..60954c7b4dfe 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -344,6 +344,7 @@ extern const struct ethnl_request_ops 
ethnl_coalesce_request_ops;
 extern const struct ethnl_request_ops ethnl_pause_request_ops;
 extern const struct ethnl_request_ops ethnl_eee_request_ops;
 extern const struct ethnl_request_ops ethnl_tsinfo_request_ops;
+extern const struct ethnl_request_ops ethnl_eeprom_data_request_ops;
 
 extern const struct nla_policy ethnl_header_policy[ETHTOOL_A_HEADER_FLAGS + 1];
 extern const struct nla_policy 
ethnl_header_policy_stats[ETHTOOL_A_HEADER_FLAGS + 1];
@@ -375,6 +376,7 @@ extern const struct nla_policy 
ethnl_tsinfo_get_policy[ETHTOOL_A_TSINFO_HEADER +
 extern const struct nla_policy 
ethnl_cable_test_act_policy[ETHTOOL_A_CABLE_TEST_HEADER + 1];
 extern const struct nla_policy 
ethnl_cable_test_tdr_act_policy[ETHTOOL_A_CABLE_TEST_TDR_CFG + 1];
 extern const struct nla_policy 
ethnl_tunnel_info_get_policy[ETHTOOL_A_TUNNEL_INFO_HEADER + 1];
+extern const struct nla_policy 
ethnl_eeprom_data_get_policy[ETHTOOL_A_EEPROM_DATA + 1];
 
 int ethnl_set_linkinfo(struct sk_buff *skb, struct genl_info *info);
 int ethnl_set_linkmodes(struct sk_buff *skb, struct genl_info *info);
-- 
2.18.2

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