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ethtool: Allow network drivers to dump arbitrary EEPROM data
authorVladyslav Tarasiuk <vladyslavt@nvidia.com>
Fri, 9 Apr 2021 08:06:34 +0000 (11:06 +0300)
committerDavid S. Miller <davem@davemloft.net>
Sun, 11 Apr 2021 23:34:56 +0000 (16:34 -0700)
Define get_module_eeprom_by_page() ethtool callback and implement
netlink infrastructure.

get_module_eeprom_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 <vladyslavt@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Documentation/networking/ethtool-netlink.rst
include/linux/ethtool.h
include/uapi/linux/ethtool_netlink.h
net/ethtool/Makefile
net/ethtool/eeprom.c [new file with mode: 0644]
net/ethtool/netlink.c
net/ethtool/netlink.h

index ce4a69f..bbecffc 100644 (file)
@@ -1338,6 +1338,38 @@ in an implementation specific way.
 ``ETHTOOL_A_FEC_AUTO`` requests the driver to choose FEC mode based on SFP
 module parameters. This does not mean autonegotiation.
 
+MODULE_EEPROM
+=============
+
+Fetch module EEPROM data dump.
+This interface is designed to allow dumps of at most 1/2 page at once. This
+means only dumps of 128 (or less) bytes are allowed, without crossing half page
+boundary located at offset 128. For pages other than 0 only high 128 bytes are
+accessible.
+
+Request contents:
+
+  =======================================  ======  ==========================
+  ``ETHTOOL_A_MODULE_EEPROM_HEADER``       nested  request header
+  ``ETHTOOL_A_MODULE_EEPROM_OFFSET``       u32     offset within a page
+  ``ETHTOOL_A_MODULE_EEPROM_LENGTH``       u32     amount of bytes to read
+  ``ETHTOOL_A_MODULE_EEPROM_PAGE``         u8      page number
+  ``ETHTOOL_A_MODULE_EEPROM_BANK``         u8      bank number
+  ``ETHTOOL_A_MODULE_EEPROM_I2C_ADDRESS``  u8      page I2C address
+  =======================================  ======  ==========================
+
+Kernel response contents:
+
+ +---------------------------------------------+--------+---------------------+
+ | ``ETHTOOL_A_MODULE_EEPROM_HEADER``          | nested | reply header        |
+ +---------------------------------------------+--------+---------------------+
+ | ``ETHTOOL_A_MODULE_EEPROM_DATA``            | nested | array of bytes from |
+ |                                             |        | module EEPROM       |
+ +---------------------------------------------+--------+---------------------+
+
+``ETHTOOL_A_MODULE_EEPROM_DATA`` has an attribute length equal to the amount of
+bytes driver actually read.
+
 Request translation
 ===================
 
@@ -1415,8 +1447,8 @@ are netlink only.
   ``ETHTOOL_GET_DUMP_FLAG``           n/a
   ``ETHTOOL_GET_DUMP_DATA``           n/a
   ``ETHTOOL_GET_TS_INFO``             ``ETHTOOL_MSG_TSINFO_GET``
-  ``ETHTOOL_GMODULEINFO``             n/a
-  ``ETHTOOL_GMODULEEEPROM``           n/a
+  ``ETHTOOL_GMODULEINFO``             ``ETHTOOL_MSG_MODULE_EEPROM_GET``
+  ``ETHTOOL_GMODULEEEPROM``           ``ETHTOOL_MSG_MODULE_EEPROM_GET``
   ``ETHTOOL_GEEE``                    ``ETHTOOL_MSG_EEE_GET``
   ``ETHTOOL_SEEE``                    ``ETHTOOL_MSG_EEE_SET``
   ``ETHTOOL_GRSSH``                   n/a
index 4290e2f..9f6f323 100644 (file)
@@ -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);
@@ -262,6 +263,31 @@ struct ethtool_pause_stats {
        u64 rx_pause_frames;
 };
 
+#define ETH_MODULE_EEPROM_PAGE_LEN     128
+#define ETH_MODULE_MAX_I2C_ADDRESS     0x7f
+
+/**
+ * struct ethtool_module_eeprom - 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_module_eeprom {
+       __u32   offset;
+       __u32   length;
+       __u8    page;
+       __u8    bank;
+       __u8    i2c_address;
+       __u8    *data;
+};
+
 /**
  * struct ethtool_ops - optional netdev operations
  * @cap_link_lanes_supported: indicates if the driver supports lanes
@@ -414,6 +440,9 @@ struct ethtool_pause_stats {
  *     cannot use the standard PHY library helpers.
  * @get_phy_tunable: Read the value of a PHY tunable.
  * @set_phy_tunable: Set the value of a PHY tunable.
+ * @get_module_eeprom_by_page: Get a region of plug-in module EEPROM data from
+ *     specified page. Returns a negative error code or the amount of bytes
+ *     read.
  *
  * All operations are optional (i.e. the function pointer may be set
  * to %NULL) and callers must take this into account.  Callers must
@@ -519,6 +548,9 @@ 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_by_page)(struct net_device *dev,
+                                            const struct ethtool_module_eeprom *page,
+                                            struct netlink_ext_ack *extack);
 };
 
 int ethtool_check_ops(const struct ethtool_ops *ops);
@@ -542,7 +574,6 @@ 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;
 
index 7f1bdb5..9612dcd 100644 (file)
@@ -44,6 +44,7 @@ enum {
        ETHTOOL_MSG_TUNNEL_INFO_GET,
        ETHTOOL_MSG_FEC_GET,
        ETHTOOL_MSG_FEC_SET,
+       ETHTOOL_MSG_MODULE_EEPROM_GET,
 
        /* add new constants above here */
        __ETHTOOL_MSG_USER_CNT,
@@ -84,6 +85,7 @@ enum {
        ETHTOOL_MSG_TUNNEL_INFO_GET_REPLY,
        ETHTOOL_MSG_FEC_GET_REPLY,
        ETHTOOL_MSG_FEC_NTF,
+       ETHTOOL_MSG_MODULE_EEPROM_GET_REPLY,
 
        /* add new constants above here */
        __ETHTOOL_MSG_KERNEL_CNT,
@@ -646,6 +648,23 @@ enum {
        ETHTOOL_A_FEC_MAX = (__ETHTOOL_A_FEC_CNT - 1)
 };
 
+/* MODULE EEPROM */
+
+enum {
+       ETHTOOL_A_MODULE_EEPROM_UNSPEC,
+       ETHTOOL_A_MODULE_EEPROM_HEADER,                 /* nest - _A_HEADER_* */
+
+       ETHTOOL_A_MODULE_EEPROM_OFFSET,                 /* u32 */
+       ETHTOOL_A_MODULE_EEPROM_LENGTH,                 /* u32 */
+       ETHTOOL_A_MODULE_EEPROM_PAGE,                   /* u8 */
+       ETHTOOL_A_MODULE_EEPROM_BANK,                   /* u8 */
+       ETHTOOL_A_MODULE_EEPROM_I2C_ADDRESS,            /* u8 */
+       ETHTOOL_A_MODULE_EEPROM_DATA,                   /* nested */
+
+       __ETHTOOL_A_MODULE_EEPROM_CNT,
+       ETHTOOL_A_MODULE_EEPROM_MAX = (__ETHTOOL_A_MODULE_EEPROM_CNT - 1)
+};
+
 /* generic netlink info */
 #define ETHTOOL_GENL_NAME "ethtool"
 #define ETHTOOL_GENL_VERSION 1
index c2dc903..8384268 100644 (file)
@@ -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 fec.o
+                  tunnels.o fec.o eeprom.o
diff --git a/net/ethtool/eeprom.c b/net/ethtool/eeprom.c
new file mode 100644 (file)
index 0000000..8536dd9
--- /dev/null
@@ -0,0 +1,171 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/ethtool.h>
+#include "netlink.h"
+#include "common.h"
+
+struct eeprom_req_info {
+       struct ethnl_req_info   base;
+       u32                     offset;
+       u32                     length;
+       u8                      page;
+       u8                      bank;
+       u8                      i2c_address;
+};
+
+struct eeprom_reply_data {
+       struct ethnl_reply_data base;
+       u32                     length;
+       u8                      *data;
+};
+
+#define MODULE_EEPROM_REQINFO(__req_base) \
+       container_of(__req_base, struct eeprom_req_info, base)
+
+#define MODULE_EEPROM_REPDATA(__reply_base) \
+       container_of(__reply_base, struct eeprom_reply_data, base)
+
+static int eeprom_prepare_data(const struct ethnl_req_info *req_base,
+                              struct ethnl_reply_data *reply_base,
+                              struct genl_info *info)
+{
+       struct eeprom_reply_data *reply = MODULE_EEPROM_REPDATA(reply_base);
+       struct eeprom_req_info *request = MODULE_EEPROM_REQINFO(req_base);
+       struct ethtool_module_eeprom page_data = {0};
+       struct net_device *dev = reply_base->dev;
+       int ret;
+
+       if (!dev->ethtool_ops->get_module_eeprom_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;
+
+       ret = ethnl_ops_begin(dev);
+       if (ret)
+               goto err_free;
+
+       ret = dev->ethtool_ops->get_module_eeprom_by_page(dev, &page_data,
+                                                         info->extack);
+       if (ret < 0)
+               goto err_ops;
+
+       reply->length = ret;
+       reply->data = page_data.data;
+
+       ethnl_ops_complete(dev);
+       return 0;
+
+err_ops:
+       ethnl_ops_complete(dev);
+err_free:
+       kfree(page_data.data);
+       return ret;
+}
+
+static int eeprom_parse_request(struct ethnl_req_info *req_info, struct nlattr **tb,
+                               struct netlink_ext_ack *extack)
+{
+       struct eeprom_req_info *request = MODULE_EEPROM_REQINFO(req_info);
+
+       if (!tb[ETHTOOL_A_MODULE_EEPROM_OFFSET] ||
+           !tb[ETHTOOL_A_MODULE_EEPROM_LENGTH] ||
+           !tb[ETHTOOL_A_MODULE_EEPROM_PAGE] ||
+           !tb[ETHTOOL_A_MODULE_EEPROM_I2C_ADDRESS])
+               return -EINVAL;
+
+       request->i2c_address = nla_get_u8(tb[ETHTOOL_A_MODULE_EEPROM_I2C_ADDRESS]);
+       request->offset = nla_get_u32(tb[ETHTOOL_A_MODULE_EEPROM_OFFSET]);
+       request->length = nla_get_u32(tb[ETHTOOL_A_MODULE_EEPROM_LENGTH]);
+
+       if (!request->length)
+               return -EINVAL;
+
+       /* The following set of conditions limit the API to only dump 1/2
+        * EEPROM page without crossing low page boundary located at offset 128.
+        * This means user may only request dumps of length limited to 128 from
+        * either low 128 bytes or high 128 bytes.
+        * For pages higher than 0 only high 128 bytes are accessible.
+        */
+       request->page = nla_get_u8(tb[ETHTOOL_A_MODULE_EEPROM_PAGE]);
+       if (request->page && request->offset < ETH_MODULE_EEPROM_PAGE_LEN) {
+               NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_MODULE_EEPROM_PAGE],
+                                   "reading from lower half page is allowed for page 0 only");
+               return -EINVAL;
+       }
+
+       if (request->offset < ETH_MODULE_EEPROM_PAGE_LEN &&
+           request->offset + request->length > ETH_MODULE_EEPROM_PAGE_LEN) {
+               NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_MODULE_EEPROM_LENGTH],
+                                   "reading cross half page boundary is illegal");
+               return -EINVAL;
+       } else if (request->offset >= ETH_MODULE_EEPROM_PAGE_LEN * 2) {
+               NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_MODULE_EEPROM_OFFSET],
+                                   "offset is out of bounds");
+               return -EINVAL;
+       } else if (request->offset + request->length > ETH_MODULE_EEPROM_PAGE_LEN * 2) {
+               NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_MODULE_EEPROM_LENGTH],
+                                   "reading cross page boundary is illegal");
+               return -EINVAL;
+       }
+
+       if (tb[ETHTOOL_A_MODULE_EEPROM_BANK])
+               request->bank = nla_get_u8(tb[ETHTOOL_A_MODULE_EEPROM_BANK]);
+
+       return 0;
+}
+
+static int eeprom_reply_size(const struct ethnl_req_info *req_base,
+                            const struct ethnl_reply_data *reply_base)
+{
+       const struct eeprom_req_info *request = MODULE_EEPROM_REQINFO(req_base);
+
+       return nla_total_size(sizeof(u8) * request->length); /* _EEPROM_DATA */
+}
+
+static int eeprom_fill_reply(struct sk_buff *skb,
+                            const struct ethnl_req_info *req_base,
+                            const struct ethnl_reply_data *reply_base)
+{
+       struct eeprom_reply_data *reply = MODULE_EEPROM_REPDATA(reply_base);
+
+       return nla_put(skb, ETHTOOL_A_MODULE_EEPROM_DATA, reply->length, reply->data);
+}
+
+static void eeprom_cleanup_data(struct ethnl_reply_data *reply_base)
+{
+       struct eeprom_reply_data *reply = MODULE_EEPROM_REPDATA(reply_base);
+
+       kfree(reply->data);
+}
+
+const struct ethnl_request_ops ethnl_module_eeprom_request_ops = {
+       .request_cmd            = ETHTOOL_MSG_MODULE_EEPROM_GET,
+       .reply_cmd              = ETHTOOL_MSG_MODULE_EEPROM_GET_REPLY,
+       .hdr_attr               = ETHTOOL_A_MODULE_EEPROM_HEADER,
+       .req_info_size          = sizeof(struct eeprom_req_info),
+       .reply_data_size        = sizeof(struct eeprom_reply_data),
+
+       .parse_request          = eeprom_parse_request,
+       .prepare_data           = eeprom_prepare_data,
+       .reply_size             = eeprom_reply_size,
+       .fill_reply             = eeprom_fill_reply,
+       .cleanup_data           = eeprom_cleanup_data,
+};
+
+const struct nla_policy ethnl_module_eeprom_get_policy[] = {
+       [ETHTOOL_A_MODULE_EEPROM_HEADER]        = NLA_POLICY_NESTED(ethnl_header_policy),
+       [ETHTOOL_A_MODULE_EEPROM_OFFSET]        = { .type = NLA_U32 },
+       [ETHTOOL_A_MODULE_EEPROM_LENGTH]        = { .type = NLA_U32 },
+       [ETHTOOL_A_MODULE_EEPROM_PAGE]          = { .type = NLA_U8 },
+       [ETHTOOL_A_MODULE_EEPROM_BANK]          = { .type = NLA_U8 },
+       [ETHTOOL_A_MODULE_EEPROM_I2C_ADDRESS]   =
+               NLA_POLICY_RANGE(NLA_U8, 0, ETH_MODULE_MAX_I2C_ADDRESS),
+};
+
index 705a4b2..5f5d7c4 100644 (file)
@@ -246,6 +246,7 @@ ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
        [ETHTOOL_MSG_EEE_GET]           = &ethnl_eee_request_ops,
        [ETHTOOL_MSG_FEC_GET]           = &ethnl_fec_request_ops,
        [ETHTOOL_MSG_TSINFO_GET]        = &ethnl_tsinfo_request_ops,
+       [ETHTOOL_MSG_MODULE_EEPROM_GET] = &ethnl_module_eeprom_request_ops,
 };
 
 static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
@@ -931,6 +932,16 @@ static const struct genl_ops ethtool_genl_ops[] = {
                .policy = ethnl_fec_set_policy,
                .maxattr = ARRAY_SIZE(ethnl_fec_set_policy) - 1,
        },
+       {
+               .cmd    = ETHTOOL_MSG_MODULE_EEPROM_GET,
+               .flags  = GENL_UNS_ADMIN_PERM,
+               .doit   = ethnl_default_doit,
+               .start  = ethnl_default_start,
+               .dumpit = ethnl_default_dumpit,
+               .done   = ethnl_default_done,
+               .policy = ethnl_module_eeprom_get_policy,
+               .maxattr = ARRAY_SIZE(ethnl_module_eeprom_get_policy) - 1,
+       },
 };
 
 static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
index 785f7ee..4305ac9 100644 (file)
@@ -345,6 +345,7 @@ 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_fec_request_ops;
+extern const struct ethnl_request_ops ethnl_module_eeprom_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];
@@ -378,6 +379,7 @@ extern const struct nla_policy ethnl_cable_test_tdr_act_policy[ETHTOOL_A_CABLE_T
 extern const struct nla_policy ethnl_tunnel_info_get_policy[ETHTOOL_A_TUNNEL_INFO_HEADER + 1];
 extern const struct nla_policy ethnl_fec_get_policy[ETHTOOL_A_FEC_HEADER + 1];
 extern const struct nla_policy ethnl_fec_set_policy[ETHTOOL_A_FEC_AUTO + 1];
+extern const struct nla_policy ethnl_module_eeprom_get_policy[ETHTOOL_A_MODULE_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);