1 files changed, 470 insertions, 0 deletions
diff --git a/include/net/xdp_sock_drv.h b/include/net/xdp_sock_drv.h
new file mode 100644
index 000000000000..242e34f771cc
--- /dev/null
+++ b/include/net/xdp_sock_drv.h
@@ -0,0 +1,470 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Interface for implementing AF_XDP zero-copy support in drivers.
+ * Copyright(c) 2020 Intel Corporation.
+ */
+
+#ifndef _LINUX_XDP_SOCK_DRV_H
+#define _LINUX_XDP_SOCK_DRV_H
+
+#include <net/xdp_sock.h>
+#include <net/xsk_buff_pool.h>
+
+#define XDP_UMEM_MIN_CHUNK_SHIFT 11
+#define XDP_UMEM_MIN_CHUNK_SIZE (1 << XDP_UMEM_MIN_CHUNK_SHIFT)
+
+#define NETDEV_XDP_ACT_XSK	(NETDEV_XDP_ACT_BASIC |		\
+				 NETDEV_XDP_ACT_REDIRECT |	\
+				 NETDEV_XDP_ACT_XSK_ZEROCOPY)
+
+struct xsk_cb_desc {
+	void *src;
+	u8 off;
+	u8 bytes;
+};
+
+#ifdef CONFIG_XDP_SOCKETS
+
+void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries);
+bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc);
+u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, u32 max);
+void xsk_tx_release(struct xsk_buff_pool *pool);
+struct xsk_buff_pool *xsk_get_pool_from_qid(struct net_device *dev,
+					    u16 queue_id);
+void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool);
+void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool);
+void xsk_clear_rx_need_wakeup(struct xsk_buff_pool *pool);
+void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool);
+bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool);
+
+static inline u32 xsk_pool_get_headroom(struct xsk_buff_pool *pool)
+{
+	return XDP_PACKET_HEADROOM + pool->headroom;
+}
+
+static inline u32 xsk_pool_get_chunk_size(struct xsk_buff_pool *pool)
+{
+	return pool->chunk_size;
+}
+
+static inline u32 xsk_pool_get_rx_frame_size(struct xsk_buff_pool *pool)
+{
+	return xsk_pool_get_chunk_size(pool) - xsk_pool_get_headroom(pool);
+}
+
+static inline void xsk_pool_set_rxq_info(struct xsk_buff_pool *pool,
+					 struct xdp_rxq_info *rxq)
+{
+	xp_set_rxq_info(pool, rxq);
+}
+
+static inline void xsk_pool_fill_cb(struct xsk_buff_pool *pool,
+				    struct xsk_cb_desc *desc)
+{
+	xp_fill_cb(pool, desc);
+}
+
+static inline void xsk_pool_dma_unmap(struct xsk_buff_pool *pool,
+				      unsigned long attrs)
+{
+	xp_dma_unmap(pool, attrs);
+}
+
+static inline int xsk_pool_dma_map(struct xsk_buff_pool *pool,
+				   struct device *dev, unsigned long attrs)
+{
+	struct xdp_umem *umem = pool->umem;
+
+	return xp_dma_map(pool, dev, attrs, umem->pgs, umem->npgs);
+}
+
+static inline dma_addr_t xsk_buff_xdp_get_dma(struct xdp_buff *xdp)
+{
+	struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
+
+	return xp_get_dma(xskb);
+}
+
+static inline dma_addr_t xsk_buff_xdp_get_frame_dma(struct xdp_buff *xdp)
+{
+	struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
+
+	return xp_get_frame_dma(xskb);
+}
+
+static inline struct xdp_buff *xsk_buff_alloc(struct xsk_buff_pool *pool)
+{
+	return xp_alloc(pool);
+}
+
+static inline bool xsk_is_eop_desc(const struct xdp_desc *desc)
+{
+	return !xp_mb_desc(desc);
+}
+
+/* Returns as many entries as possible up to max. 0 <= N <= max. */
+static inline u32 xsk_buff_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
+{
+	return xp_alloc_batch(pool, xdp, max);
+}
+
+static inline bool xsk_buff_can_alloc(struct xsk_buff_pool *pool, u32 count)
+{
+	return xp_can_alloc(pool, count);
+}
+
+static inline void xsk_buff_free(struct xdp_buff *xdp)
+{
+	struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
+	struct list_head *xskb_list = &xskb->pool->xskb_list;
+	struct xdp_buff_xsk *pos, *tmp;
+
+	if (likely(!xdp_buff_has_frags(xdp)))
+		goto out;
+
+	list_for_each_entry_safe(pos, tmp, xskb_list, list_node) {
+		list_del(&pos->list_node);
+		xp_free(pos);
+	}
+
+	xdp_get_shared_info_from_buff(xdp)->nr_frags = 0;
+out:
+	xp_free(xskb);
+}
+
+static inline bool xsk_buff_add_frag(struct xdp_buff *head,
+				     struct xdp_buff *xdp)
+{
+	const void *data = xdp->data;
+	struct xdp_buff_xsk *frag;
+
+	if (!__xdp_buff_add_frag(head, virt_to_netmem(data),
+				 offset_in_page(data), xdp->data_end - data,
+				 xdp->frame_sz, false))
+		return false;
+
+	frag = container_of(xdp, struct xdp_buff_xsk, xdp);
+	list_add_tail(&frag->list_node, &frag->pool->xskb_list);
+
+	return true;
+}
+
+static inline struct xdp_buff *xsk_buff_get_frag(const struct xdp_buff *first)
+{
+	struct xdp_buff_xsk *xskb = container_of(first, struct xdp_buff_xsk, xdp);
+	struct xdp_buff *ret = NULL;
+	struct xdp_buff_xsk *frag;
+
+	frag = list_first_entry_or_null(&xskb->pool->xskb_list,
+					struct xdp_buff_xsk, list_node);
+	if (frag) {
+		list_del(&frag->list_node);
+		ret = &frag->xdp;
+	}
+
+	return ret;
+}
+
+static inline void xsk_buff_del_frag(struct xdp_buff *xdp)
+{
+	struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
+
+	list_del(&xskb->list_node);
+}
+
+static inline struct xdp_buff *xsk_buff_get_head(struct xdp_buff *first)
+{
+	struct xdp_buff_xsk *xskb = container_of(first, struct xdp_buff_xsk, xdp);
+	struct xdp_buff_xsk *frag;
+
+	frag = list_first_entry(&xskb->pool->xskb_list, struct xdp_buff_xsk,
+				list_node);
+	return &frag->xdp;
+}
+
+static inline struct xdp_buff *xsk_buff_get_tail(struct xdp_buff *first)
+{
+	struct xdp_buff_xsk *xskb = container_of(first, struct xdp_buff_xsk, xdp);
+	struct xdp_buff_xsk *frag;
+
+	frag = list_last_entry(&xskb->pool->xskb_list, struct xdp_buff_xsk,
+			       list_node);
+	return &frag->xdp;
+}
+
+static inline void xsk_buff_set_size(struct xdp_buff *xdp, u32 size)
+{
+	xdp->data = xdp->data_hard_start + XDP_PACKET_HEADROOM;
+	xdp->data_meta = xdp->data;
+	xdp->data_end = xdp->data + size;
+	xdp->flags = 0;
+}
+
+static inline dma_addr_t xsk_buff_raw_get_dma(struct xsk_buff_pool *pool,
+					      u64 addr)
+{
+	return xp_raw_get_dma(pool, addr);
+}
+
+static inline void *xsk_buff_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
+{
+	return xp_raw_get_data(pool, addr);
+}
+
+/**
+ * xsk_buff_raw_get_ctx - get &xdp_desc context
+ * @pool: XSk buff pool desc address belongs to
+ * @addr: desc address (from userspace)
+ *
+ * Wrapper for xp_raw_get_ctx() to be used in drivers, see its kdoc for
+ * details.
+ *
+ * Return: new &xdp_desc_ctx struct containing desc's DMA address and metadata
+ * pointer, if it is present and valid (initialized to %NULL otherwise).
+ */
+static inline struct xdp_desc_ctx
+xsk_buff_raw_get_ctx(const struct xsk_buff_pool *pool, u64 addr)
+{
+	return xp_raw_get_ctx(pool, addr);
+}
+
+#define XDP_TXMD_FLAGS_VALID ( \
+		XDP_TXMD_FLAGS_TIMESTAMP | \
+		XDP_TXMD_FLAGS_CHECKSUM | \
+		XDP_TXMD_FLAGS_LAUNCH_TIME | \
+	0)
+
+static inline bool
+xsk_buff_valid_tx_metadata(const struct xsk_tx_metadata *meta)
+{
+	return !(meta->flags & ~XDP_TXMD_FLAGS_VALID);
+}
+
+static inline struct xsk_tx_metadata *
+__xsk_buff_get_metadata(const struct xsk_buff_pool *pool, void *data)
+{
+	struct xsk_tx_metadata *meta;
+
+	if (!pool->tx_metadata_len)
+		return NULL;
+
+	meta = data - pool->tx_metadata_len;
+	if (unlikely(!xsk_buff_valid_tx_metadata(meta)))
+		return NULL; /* no way to signal the error to the user */
+
+	return meta;
+}
+
+static inline struct xsk_tx_metadata *
+xsk_buff_get_metadata(struct xsk_buff_pool *pool, u64 addr)
+{
+	return __xsk_buff_get_metadata(pool, xp_raw_get_data(pool, addr));
+}
+
+static inline void xsk_buff_dma_sync_for_cpu(struct xdp_buff *xdp)
+{
+	struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
+
+	xp_dma_sync_for_cpu(xskb);
+}
+
+static inline void xsk_buff_raw_dma_sync_for_device(struct xsk_buff_pool *pool,
+						    dma_addr_t dma,
+						    size_t size)
+{
+	xp_dma_sync_for_device(pool, dma, size);
+}
+
+#else
+
+static inline void xsk_tx_completed(struct xsk_buff_pool *pool, u32 nb_entries)
+{
+}
+
+static inline bool xsk_tx_peek_desc(struct xsk_buff_pool *pool,
+				    struct xdp_desc *desc)
+{
+	return false;
+}
+
+static inline u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, u32 max)
+{
+	return 0;
+}
+
+static inline void xsk_tx_release(struct xsk_buff_pool *pool)
+{
+}
+
+static inline struct xsk_buff_pool *
+xsk_get_pool_from_qid(struct net_device *dev, u16 queue_id)
+{
+	return NULL;
+}
+
+static inline void xsk_set_rx_need_wakeup(struct xsk_buff_pool *pool)
+{
+}
+
+static inline void xsk_set_tx_need_wakeup(struct xsk_buff_pool *pool)
+{
+}
+
+static inline void xsk_clear_rx_need_wakeup(struct xsk_buff_pool *pool)
+{
+}
+
+static inline void xsk_clear_tx_need_wakeup(struct xsk_buff_pool *pool)
+{
+}
+
+static inline bool xsk_uses_need_wakeup(struct xsk_buff_pool *pool)
+{
+	return false;
+}
+
+static inline u32 xsk_pool_get_headroom(struct xsk_buff_pool *pool)
+{
+	return 0;
+}
+
+static inline u32 xsk_pool_get_chunk_size(struct xsk_buff_pool *pool)
+{
+	return 0;
+}
+
+static inline u32 xsk_pool_get_rx_frame_size(struct xsk_buff_pool *pool)
+{
+	return 0;
+}
+
+static inline void xsk_pool_set_rxq_info(struct xsk_buff_pool *pool,
+					 struct xdp_rxq_info *rxq)
+{
+}
+
+static inline void xsk_pool_fill_cb(struct xsk_buff_pool *pool,
+				    struct xsk_cb_desc *desc)
+{
+}
+
+static inline void xsk_pool_dma_unmap(struct xsk_buff_pool *pool,
+				      unsigned long attrs)
+{
+}
+
+static inline int xsk_pool_dma_map(struct xsk_buff_pool *pool,
+				   struct device *dev, unsigned long attrs)
+{
+	return 0;
+}
+
+static inline dma_addr_t xsk_buff_xdp_get_dma(struct xdp_buff *xdp)
+{
+	return 0;
+}
+
+static inline dma_addr_t xsk_buff_xdp_get_frame_dma(struct xdp_buff *xdp)
+{
+	return 0;
+}
+
+static inline struct xdp_buff *xsk_buff_alloc(struct xsk_buff_pool *pool)
+{
+	return NULL;
+}
+
+static inline bool xsk_is_eop_desc(const struct xdp_desc *desc)
+{
+	return false;
+}
+
+static inline u32 xsk_buff_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
+{
+	return 0;
+}
+
+static inline bool xsk_buff_can_alloc(struct xsk_buff_pool *pool, u32 count)
+{
+	return false;
+}
+
+static inline void xsk_buff_free(struct xdp_buff *xdp)
+{
+}
+
+static inline bool xsk_buff_add_frag(struct xdp_buff *head,
+				     struct xdp_buff *xdp)
+{
+	return false;
+}
+
+static inline struct xdp_buff *xsk_buff_get_frag(const struct xdp_buff *first)
+{
+	return NULL;
+}
+
+static inline void xsk_buff_del_frag(struct xdp_buff *xdp)
+{
+}
+
+static inline struct xdp_buff *xsk_buff_get_head(struct xdp_buff *first)
+{
+	return NULL;
+}
+
+static inline struct xdp_buff *xsk_buff_get_tail(struct xdp_buff *first)
+{
+	return NULL;
+}
+
+static inline void xsk_buff_set_size(struct xdp_buff *xdp, u32 size)
+{
+}
+
+static inline dma_addr_t xsk_buff_raw_get_dma(struct xsk_buff_pool *pool,
+					      u64 addr)
+{
+	return 0;
+}
+
+static inline void *xsk_buff_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
+{
+	return NULL;
+}
+
+static inline struct xdp_desc_ctx
+xsk_buff_raw_get_ctx(const struct xsk_buff_pool *pool, u64 addr)
+{
+	return (struct xdp_desc_ctx){ };
+}
+
+static inline bool xsk_buff_valid_tx_metadata(struct xsk_tx_metadata *meta)
+{
+	return false;
+}
+
+static inline struct xsk_tx_metadata *
+__xsk_buff_get_metadata(const struct xsk_buff_pool *pool, void *data)
+{
+	return NULL;
+}
+
+static inline struct xsk_tx_metadata *
+xsk_buff_get_metadata(struct xsk_buff_pool *pool, u64 addr)
+{
+	return NULL;
+}
+
+static inline void xsk_buff_dma_sync_for_cpu(struct xdp_buff *xdp)
+{
+}
+
+static inline void xsk_buff_raw_dma_sync_for_device(struct xsk_buff_pool *pool,
+						    dma_addr_t dma,
+						    size_t size)
+{
+}
+
+#endif /* CONFIG_XDP_SOCKETS */
+
+#endif /* _LINUX_XDP_SOCK_DRV_H */