devlink: make sure driver does not read updated driverinit param before reload

The driverinit param purpose is to serve the driver during init/reload
time to provide a value, either default or set by user.

Make sure that driver does not read value updated by user before the
reload is performed. Hold the new value in a separate struct and switch
it during reload.

Note that this is required to be eventually possible to call
devl_param_driverinit_value_get() without holding instance lock.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/devlink.h b/include/net/devlink.h
index 2e85a59..8ed9603 100644 (file)
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -489,6 +489,10 @@ struct devlink_param_item {
        const struct devlink_param *param;
        union devlink_param_value driverinit_value;
        bool driverinit_value_valid;
+       union devlink_param_value driverinit_value_new; /* Not reachable
+                                                        * until reload.
+                                                        */
+       bool driverinit_value_new_valid;
 };
 
 enum devlink_param_generic_id {

diff --git a/net/devlink/dev.c b/net/devlink/dev.c
index 7cf2de4..ab4e0f3 100644 (file)
--- a/net/devlink/dev.c
+++ b/net/devlink/dev.c
@@ -369,6 +369,9 @@ int devlink_reload(struct devlink *devlink, struct net *dest_net,
        if (dest_net && !net_eq(dest_net, curr_net))
                devlink_reload_netns_change(devlink, curr_net, dest_net);
 
+       if (action == DEVLINK_RELOAD_ACTION_DRIVER_REINIT)
+               devlink_params_driverinit_load_new(devlink);
+
        err = devlink->ops->reload_up(devlink, action, limit, actions_performed, extack);
        devlink_reload_failed_set(devlink, !!err);
        if (err)

diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h
index 941174e..5c117e8 100644 (file)
--- a/net/devlink/devl_internal.h
+++ b/net/devlink/devl_internal.h
@@ -189,6 +189,9 @@ static inline bool devlink_reload_supported(const struct devlink_ops *ops)
        return ops->reload_down && ops->reload_up;
 }
 
+/* Params */
+void devlink_params_driverinit_load_new(struct devlink *devlink);
+
 /* Resources */
 struct devlink_resource;
 int devlink_resources_validate(struct devlink *devlink,

diff --git a/net/devlink/leftover.c b/net/devlink/leftover.c
index 2f9e309..f74aca8 100644 (file)
--- a/net/devlink/leftover.c
+++ b/net/devlink/leftover.c
@@ -4097,9 +4097,12 @@ static int devlink_nl_param_fill(struct sk_buff *msg, struct devlink *devlink,
                if (!devlink_param_cmode_is_supported(param, i))
                        continue;
                if (i == DEVLINK_PARAM_CMODE_DRIVERINIT) {
-                       if (!param_item->driverinit_value_valid)
+                       if (param_item->driverinit_value_new_valid)
+                               param_value[i] = param_item->driverinit_value_new;
+                       else if (param_item->driverinit_value_valid)
+                               param_value[i] = param_item->driverinit_value;
+                       else
                                return -EOPNOTSUPP;
-                       param_value[i] = param_item->driverinit_value;
                } else {
                        ctx.cmode = i;
                        err = devlink_param_get(devlink, param, &ctx);
@@ -4387,8 +4390,8 @@ static int __devlink_nl_cmd_param_set_doit(struct devlink *devlink,
                return -EOPNOTSUPP;
 
        if (cmode == DEVLINK_PARAM_CMODE_DRIVERINIT) {
-               param_item->driverinit_value = value;
-               param_item->driverinit_value_valid = true;
+               param_item->driverinit_value_new = value;
+               param_item->driverinit_value_new_valid = true;
        } else {
                if (!param->set)
                        return -EOPNOTSUPP;
@@ -9690,6 +9693,21 @@ void devl_param_driverinit_value_set(struct devlink *devlink, u32 param_id,
 }
 EXPORT_SYMBOL_GPL(devl_param_driverinit_value_set);
 
+void devlink_params_driverinit_load_new(struct devlink *devlink)
+{
+       struct devlink_param_item *param_item;
+
+       list_for_each_entry(param_item, &devlink->param_list, list) {
+               if (!devlink_param_cmode_is_supported(param_item->param,
+                                                     DEVLINK_PARAM_CMODE_DRIVERINIT) ||
+                   !param_item->driverinit_value_new_valid)
+                       continue;
+               param_item->driverinit_value = param_item->driverinit_value_new;
+               param_item->driverinit_value_valid = true;
+               param_item->driverinit_value_new_valid = false;
+       }
+}
+
 /**
  *     devl_param_value_changed - notify devlink on a parameter's value
  *                                change. Should be called by the driver