Merge branch 'xdp-a-fistful-of-generic-changes-pt-i'

Alexander Lobakin says:

====================
xdp: a fistful of generic changes pt. I

XDP for idpf is currently 6 chapters:
* convert Rx to libeth;
* convert Tx and stats to libeth;
* generic XDP and XSk code changes (you are here);
* generic XDP and XSk code additions;
* actual XDP for idpf via new libeth_xdp;
* XSk for idpf (via ^).

Part III does the following:
* improve &xdp_buff_xsk cacheline placement;
* does some cleanups with marking read-only bpf_prog and xdp_buff
  arguments const for some generic functions;
* allows attaching already registered XDP memory model to RxQ info;
* makes system percpu page_pools valid XDP memory models;
* starts using netmems in the XDP core code (1 function);
* allows mixing pages from several page_pools within one XDP frame;
* optimizes &xdp_frame layout and removes no-more-used field.

Bullets 4-6 are the most important ones. All of them are prereqs to
libeth_xdp.
====================

Link: https://patch.msgid.link/20241203173733.3181246-1-aleksander.lobakin@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 14 insertions, 6 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 45a8c3dd4a64..c7f3dea3e0eb 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -460,7 +460,7 @@ EXPORT_PER_CPU_SYMBOL(softnet_data);
  * PP consumers must pay attention to run APIs in the appropriate context
  * (e.g. NAPI context).
  */
-static DEFINE_PER_CPU(struct page_pool *, system_page_pool);
+DEFINE_PER_CPU(struct page_pool *, system_page_pool);
 
 #ifdef CONFIG_LOCKDEP
 /*
@@ -4931,7 +4931,7 @@ static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb)
 }
 
 u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
-			     struct bpf_prog *xdp_prog)
+			     const struct bpf_prog *xdp_prog)
 {
 	void *orig_data, *orig_data_end, *hard_start;
 	struct netdev_rx_queue *rxqueue;
@@ -5033,7 +5033,7 @@ u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
 }
 
 static int
-netif_skb_check_for_xdp(struct sk_buff **pskb, struct bpf_prog *prog)
+netif_skb_check_for_xdp(struct sk_buff **pskb, const struct bpf_prog *prog)
 {
 	struct sk_buff *skb = *pskb;
 	int err, hroom, troom;
@@ -5057,7 +5057,7 @@ netif_skb_check_for_xdp(struct sk_buff **pskb, struct bpf_prog *prog)
 
 static u32 netif_receive_generic_xdp(struct sk_buff **pskb,
 				     struct xdp_buff *xdp,
-				     struct bpf_prog *xdp_prog)
+				     const struct bpf_prog *xdp_prog)
 {
 	struct sk_buff *skb = *pskb;
 	u32 mac_len, act = XDP_DROP;
@@ -5110,7 +5110,7 @@ static u32 netif_receive_generic_xdp(struct sk_buff **pskb,
  * and DDOS attacks will be more effective. In-driver-XDP use dedicated TX
  * queues, so they do not have this starvation issue.
  */
-void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
+void generic_xdp_tx(struct sk_buff *skb, const struct bpf_prog *xdp_prog)
 {
 	struct net_device *dev = skb->dev;
 	struct netdev_queue *txq;
@@ -5135,7 +5135,7 @@ void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
 
 static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key);
 
-int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff **pskb)
+int do_xdp_generic(const struct bpf_prog *xdp_prog, struct sk_buff **pskb)
 {
 	struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx;
 
@@ -12152,11 +12152,18 @@ static int net_page_pool_create(int cpuid)
 		.nid = cpu_to_mem(cpuid),
 	};
 	struct page_pool *pp_ptr;
+	int err;
 
 	pp_ptr = page_pool_create_percpu(&page_pool_params, cpuid);
 	if (IS_ERR(pp_ptr))
 		return -ENOMEM;
 
+	err = xdp_reg_page_pool(pp_ptr);
+	if (err) {
+		page_pool_destroy(pp_ptr);
+		return err;
+	}
+
 	per_cpu(system_page_pool, cpuid) = pp_ptr;
 #endif
 	return 0;
@@ -12290,6 +12297,7 @@ out:
 			if (!pp_ptr)
 				continue;
 
+			xdp_unreg_page_pool(pp_ptr);
 			page_pool_destroy(pp_ptr);
 			per_cpu(system_page_pool, i) = NULL;
 		}