On Wed, May 15, 2024 at 04:41:09PM +0200, Andrew Lunn wrote:

quoted

+ * 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*/
+};

...

quoted

+	/** 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);

quoted

+ * 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);

Hi Andrew,

I think that, initially at least, the implementation of
net_shaper_make_handle() can be fairly simple, involving packing
fields into an integer in a static manner.

As such I think implementing a helper or helpers to an to extract fields
should be trivial.

In other words, yes, I think that can be added.