Commit 847a8ab1 authored by Edward Cree's avatar Edward Cree Committed by Jakub Kicinski
Browse files

net: ethtool: let the core choose RSS context IDs 



Add a new API to create/modify/remove RSS contexts, that passes in the
 newly-chosen context ID (not as a pointer) rather than leaving the
 driver to choose it on create.  Also pass in the ctx, allowing drivers
 to easily use its private data area to store their hardware-specific
 state.
Keep the existing .set_rxfh API for now as a fallback, but deprecate it
 for custom contexts (rss_context != 0).

Signed-off-by: default avatarEdward Cree <ecree.xilinx@gmail.com>
Reviewed-by: default avatarPrzemek Kitszel <przemyslaw.kitszel@intel.com>
Link: https://patch.msgid.link/45f1fe61df2163c091ec394c9f52000c8b16cc3b.1719502240.git.ecree.xilinx@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent eac9122f

include/linux/ethtool.h

+40 −0
Original line number Diff line number Diff line
@@ -723,6 +723,10 @@ struct ethtool_rxfh_param { 
 *	RSS.

 * @rxfh_priv_size: size of the driver private data area the core should

 *	allocate for an RSS context (in &struct ethtool_rxfh_context).

 * @rxfh_max_context_id: maximum (exclusive) supported RSS context ID.  If this

 *	is zero then the core may choose any (nonzero) ID, otherwise the core

 *	will only use IDs strictly less than this value, as the @rss_context

 *	argument to @create_rxfh_context and friends.

 * @supported_coalesce_params: supported types of interrupt coalescing.

 * @supported_ring_params: supported ring params.

 * @get_drvinfo: Report driver/device information. Modern drivers no
@@ -819,6 +823,32 @@ struct ethtool_rxfh_param { 
 *	will remain unchanged.

 *	Returns a negative error code or zero. An error code must be returned

 *	if at least one unsupported change was requested.

 * @create_rxfh_context: Create a new RSS context with the specified RX flow

 *	hash indirection table, hash key, and hash function.

 *	The &struct ethtool_rxfh_context for this context is passed in @ctx;

 *	note that the indir table, hkey and hfunc are not yet populated as

 *	of this call.  The driver does not need to update these; the core

 *	will do so if this op succeeds.

 *	However, if @rxfh.indir is set to %NULL, the driver must update the

 *	indir table in @ctx with the (default or inherited) table actually in

 *	use; similarly, if @rxfh.key is %NULL, @rxfh.hfunc is

 *	%ETH_RSS_HASH_NO_CHANGE, or @rxfh.input_xfrm is %RXH_XFRM_NO_CHANGE,

 *	the driver should update the corresponding information in @ctx.

 *	If the driver provides this method, it must also provide

 *	@modify_rxfh_context and @remove_rxfh_context.

 *	Returns a negative error code or zero.

 * @modify_rxfh_context: Reconfigure the specified RSS context.  Allows setting

 *	the contents of the RX flow hash indirection table, hash key, and/or

 *	hash function associated with the given context.

 *	Parameters which are set to %NULL or zero will remain unchanged.

 *	The &struct ethtool_rxfh_context for this context is passed in @ctx;

 *	note that it will still contain the *old* settings.  The driver does

 *	not need to update these; the core will do so if this op succeeds.

 *	Returns a negative error code or zero. An error code must be returned

 *	if at least one unsupported change was requested.

 * @remove_rxfh_context: Remove the specified RSS context.

 *	The &struct ethtool_rxfh_context for this context is passed in @ctx.

 *	Returns a negative error code or zero.

 * @get_channels: Get number of channels.

 * @set_channels: Set number of channels.  Returns a negative error code or

 *	zero.
@@ -909,6 +939,7 @@ struct ethtool_ops { 
	u32     cap_rss_ctx_supported:1;

	u32	cap_rss_sym_xor_supported:1;

	u16	rxfh_priv_size;

	u32	rxfh_max_context_id;

	u32	supported_coalesce_params;

	u32	supported_ring_params;

	void	(*get_drvinfo)(struct net_device *, struct ethtool_drvinfo *);
@@ -971,6 +1002,15 @@ struct ethtool_ops { 
	int	(*get_rxfh)(struct net_device *, struct ethtool_rxfh_param *);

	int	(*set_rxfh)(struct net_device *, struct ethtool_rxfh_param *,

			    struct netlink_ext_ack *extack);

	int	(*create_rxfh_context)(struct net_device *,

				       struct ethtool_rxfh_context *ctx,

				       const struct ethtool_rxfh_param *rxfh);

	int	(*modify_rxfh_context)(struct net_device *,

				       struct ethtool_rxfh_context *ctx,

				       const struct ethtool_rxfh_param *rxfh);

	int	(*remove_rxfh_context)(struct net_device *,

				       struct ethtool_rxfh_context *ctx,

				       u32 rss_context);

	void	(*get_channels)(struct net_device *, struct ethtool_channels *);

	int	(*set_channels)(struct net_device *, struct ethtool_channels *);

	int	(*get_dump_flag)(struct net_device *, struct ethtool_dump *);

net/core/dev.c

+5 −1
Original line number Diff line number Diff line
@@ -11254,6 +11254,10 @@ static void netdev_rss_contexts_free(struct net_device *dev) 
		rxfh.rss_delete = true;



		xa_erase(&dev->ethtool->rss_ctx, context);

		if (dev->ethtool_ops->create_rxfh_context)

			dev->ethtool_ops->remove_rxfh_context(dev, ctx,

							      context);

		else

			dev->ethtool_ops->set_rxfh(dev, &rxfh, NULL);

		kfree(ctx);

	}

net/ethtool/ioctl.c

+34 −12
Original line number Diff line number Diff line
@@ -1395,9 +1395,24 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev, 
		}

		ctx->indir_size = dev_indir_size;

		ctx->key_size = dev_key_size;

		ctx->hfunc = rxfh.hfunc;

		ctx->input_xfrm = rxfh.input_xfrm;

		ctx->priv_size = ops->rxfh_priv_size;

		/* Initialise to an empty context */

		ctx->hfunc = ETH_RSS_HASH_NO_CHANGE;

		ctx->input_xfrm = RXH_XFRM_NO_CHANGE;

		if (ops->create_rxfh_context) {

			u32 limit = ops->rxfh_max_context_id ?: U32_MAX;

			u32 ctx_id;



			/* driver uses new API, core allocates ID */

			ret = xa_alloc(&dev->ethtool->rss_ctx, &ctx_id, ctx,

				       XA_LIMIT(1, limit), GFP_KERNEL_ACCOUNT);

			if (ret < 0) {

				kfree(ctx);

				goto out;

			}

			WARN_ON(!ctx_id); /* can't happen */

			rxfh.rss_context = ctx_id;

		}

	} else if (rxfh.rss_context) {

		ctx = xa_load(&dev->ethtool->rss_ctx, rxfh.rss_context);

		if (!ctx) {
@@ -1409,11 +1424,24 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev, 
	rxfh_dev.rss_context = rxfh.rss_context;

	rxfh_dev.input_xfrm = rxfh.input_xfrm;



	if (rxfh.rss_context && ops->create_rxfh_context) {

		if (create)

			ret = ops->create_rxfh_context(dev, ctx, &rxfh_dev);

		else if (rxfh_dev.rss_delete)

			ret = ops->remove_rxfh_context(dev, ctx,

						       rxfh.rss_context);

		else

			ret = ops->modify_rxfh_context(dev, ctx, &rxfh_dev);

	} else {

		ret = ops->set_rxfh(dev, &rxfh_dev, extack);

	}

	if (ret) {

		if (create)

		if (create) {

			/* failed to create, free our new tracking entry */

			if (ops->create_rxfh_context)

				xa_erase(&dev->ethtool->rss_ctx, rxfh.rss_context);

			kfree(ctx);

		}

		goto out;

	}
@@ -1429,12 +1457,8 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev, 
			dev->priv_flags |= IFF_RXFH_CONFIGURED;

	}

	/* Update rss_ctx tracking */

	if (create) {

		/* Ideally this should happen before calling the driver,

		 * so that we can fail more cleanly; but we don't have the

		 * context ID until the driver picks it, so we have to

		 * wait until after.

		 */

	if (create && !ops->create_rxfh_context) {

		/* driver uses old API, it chose context ID */

		if (WARN_ON(xa_load(&dev->ethtool->rss_ctx, rxfh.rss_context))) {

			/* context ID reused, our tracking is screwed */

			kfree(ctx);
@@ -1446,8 +1470,6 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev, 
			kfree(ctx);

			goto out;

		}

		ctx->indir_configured = rxfh.indir_size != ETH_RXFH_INDIR_NO_CHANGE;

		ctx->key_configured = !!rxfh.key_size;

	}

	if (rxfh_dev.rss_delete) {

		WARN_ON(xa_erase(&dev->ethtool->rss_ctx, rxfh.rss_context) != ctx);