Re: [RFC PATCH] net: introduce HW Rate Limiting Driver API
From: Andrew Lunn <andrew@lunn.ch>
Date: 2024-05-15 14:41:15
+ * struct net_shaper_info - represents a shaping node on the NIC H/W
+ * @metric: Specify if the bw limits refers to PPS or BPS
+ * @bw_min: Minimum guaranteed rate for this shaper
+ * @bw_max: Maximum peak bw allowed for this shaper
+ * @burst: Maximum burst for the peek rate of this shaper
+ * @priority: Scheduling priority for this shaper
+ * @weight: Scheduling weight for this shaper
+ */
+struct net_shaper_info {
+ enum net_shaper_metric metric;
+ u64 bw_min; /* minimum guaranteed bandwidth, according to metric */
+ u64 bw_max; /* maximum allowed bandwidth */
+ u32 burst; /* maximum burst in bytes for bw_max */
+ u32 priority; /* scheduling strict priority */
+ u32 weight; /* scheduling WRR weight*/
+};...
+ /** set - Update the specified shaper, if it exists + * @dev: Netdevice to operate on. + * @handle: the shaper identifier + * @shaper: Configuration of shaper. + * @extack: Netlink extended ACK for reporting errors. + * + * Return: + * * %0 - Success + * * %-EOPNOTSUPP - Operation is not supported by hardware, driver, + * or core for any reason. @extack should be set to + * text describing the reason. + * * Other negative error values on failure. + */ + int (*set)(struct net_device *dev, u32 handle, + const struct net_shaper_info *shaper, + struct netlink_ext_ack *extack);
+ * net_shaper_make_handle - creates an unique shaper identifier + * @scope: the shaper scope + * @vf: virtual function number + * @id: queue group or queue id + * + * Return: an unique identifier for the shaper + * + * Combines the specified arguments to create an unique identifier for + * the shaper. + * The virtual function number is only used within @NET_SHAPER_SCOPE_VF, + * @NET_SHAPER_SCOPE_QUEUE_GROUP and @NET_SHAPER_SCOPE_QUEUE. + * The @id number is only used for @NET_SHAPER_SCOPE_QUEUE_GROUP and + * @NET_SHAPER_SCOPE_QUEUE, and must be, respectively, the queue group + * identifier or the queue number. + */ +u32 net_shaper_make_handle(enum net_shaper_scope scope, int vf, int id);
One thing i'm missing here is a function which does the opposite of
net_shaper_make_handle(). Given a handle, it returns the scope, vf and
the id.
When the set() op is called, i somehow need to find the software
instance representing the hardware block. If i know the id, it is just
an array access. Otherwise i need additional bookkeeping, maybe a
linked list of handles and pointers to structures etc.
Or net_shaper_make_handle() could maybe take an addition void * priv,
and provide a function void * net_shape_priv(u32 handle);
Andrew