1 files changed, 681 insertions, 0 deletions

diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
new file mode 100644
index 000000000..ed6c71826
--- /dev/null
+++ b/net/xdp/xsk_buff_pool.c
@@ -0,0 +1,681 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <net/xsk_buff_pool.h>
+#include <net/xdp_sock.h>
+#include <net/xdp_sock_drv.h>
+
+#include "xsk_queue.h"
+#include "xdp_umem.h"
+#include "xsk.h"
+
+void xp_add_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs)
+{
+	unsigned long flags;
+
+	if (!xs->tx)
+		return;
+
+	spin_lock_irqsave(&pool->xsk_tx_list_lock, flags);
+	list_add_rcu(&xs->tx_list, &pool->xsk_tx_list);
+	spin_unlock_irqrestore(&pool->xsk_tx_list_lock, flags);
+}
+
+void xp_del_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs)
+{
+	unsigned long flags;
+
+	if (!xs->tx)
+		return;
+
+	spin_lock_irqsave(&pool->xsk_tx_list_lock, flags);
+	list_del_rcu(&xs->tx_list);
+	spin_unlock_irqrestore(&pool->xsk_tx_list_lock, flags);
+}
+
+void xp_destroy(struct xsk_buff_pool *pool)
+{
+	if (!pool)
+		return;
+
+	kvfree(pool->tx_descs);
+	kvfree(pool->heads);
+	kvfree(pool);
+}
+
+int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs)
+{
+	pool->tx_descs = kvcalloc(xs->tx->nentries, sizeof(*pool->tx_descs),
+				  GFP_KERNEL);
+	if (!pool->tx_descs)
+		return -ENOMEM;
+
+	return 0;
+}
+
+struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
+						struct xdp_umem *umem)
+{
+	bool unaligned = umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG;
+	struct xsk_buff_pool *pool;
+	struct xdp_buff_xsk *xskb;
+	u32 i, entries;
+
+	entries = unaligned ? umem->chunks : 0;
+	pool = kvzalloc(struct_size(pool, free_heads, entries),	GFP_KERNEL);
+	if (!pool)
+		goto out;
+
+	pool->heads = kvcalloc(umem->chunks, sizeof(*pool->heads), GFP_KERNEL);
+	if (!pool->heads)
+		goto out;
+
+	if (xs->tx)
+		if (xp_alloc_tx_descs(pool, xs))
+			goto out;
+
+	pool->chunk_mask = ~((u64)umem->chunk_size - 1);
+	pool->addrs_cnt = umem->size;
+	pool->heads_cnt = umem->chunks;
+	pool->free_heads_cnt = umem->chunks;
+	pool->headroom = umem->headroom;
+	pool->chunk_size = umem->chunk_size;
+	pool->chunk_shift = ffs(umem->chunk_size) - 1;
+	pool->unaligned = unaligned;
+	pool->frame_len = umem->chunk_size - umem->headroom -
+		XDP_PACKET_HEADROOM;
+	pool->umem = umem;
+	pool->addrs = umem->addrs;
+	INIT_LIST_HEAD(&pool->free_list);
+	INIT_LIST_HEAD(&pool->xsk_tx_list);
+	spin_lock_init(&pool->xsk_tx_list_lock);
+	spin_lock_init(&pool->cq_lock);
+	refcount_set(&pool->users, 1);
+
+	pool->fq = xs->fq_tmp;
+	pool->cq = xs->cq_tmp;
+
+	for (i = 0; i < pool->free_heads_cnt; i++) {
+		xskb = &pool->heads[i];
+		xskb->pool = pool;
+		xskb->xdp.frame_sz = umem->chunk_size - umem->headroom;
+		INIT_LIST_HEAD(&xskb->free_list_node);
+		if (pool->unaligned)
+			pool->free_heads[i] = xskb;
+		else
+			xp_init_xskb_addr(xskb, pool, i * pool->chunk_size);
+	}
+
+	return pool;
+
+out:
+	xp_destroy(pool);
+	return NULL;
+}
+
+void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq)
+{
+	u32 i;
+
+	for (i = 0; i < pool->heads_cnt; i++)
+		pool->heads[i].xdp.rxq = rxq;
+}
+EXPORT_SYMBOL(xp_set_rxq_info);
+
+static void xp_disable_drv_zc(struct xsk_buff_pool *pool)
+{
+	struct netdev_bpf bpf;
+	int err;
+
+	ASSERT_RTNL();
+
+	if (pool->umem->zc) {
+		bpf.command = XDP_SETUP_XSK_POOL;
+		bpf.xsk.pool = NULL;
+		bpf.xsk.queue_id = pool->queue_id;
+
+		err = pool->netdev->netdev_ops->ndo_bpf(pool->netdev, &bpf);
+
+		if (err)
+			WARN(1, "Failed to disable zero-copy!\n");
+	}
+}
+
+int xp_assign_dev(struct xsk_buff_pool *pool,
+		  struct net_device *netdev, u16 queue_id, u16 flags)
+{
+	bool force_zc, force_copy;
+	struct netdev_bpf bpf;
+	int err = 0;
+
+	ASSERT_RTNL();
+
+	force_zc = flags & XDP_ZEROCOPY;
+	force_copy = flags & XDP_COPY;
+
+	if (force_zc && force_copy)
+		return -EINVAL;
+
+	if (xsk_get_pool_from_qid(netdev, queue_id))
+		return -EBUSY;
+
+	pool->netdev = netdev;
+	pool->queue_id = queue_id;
+	err = xsk_reg_pool_at_qid(netdev, pool, queue_id);
+	if (err)
+		return err;
+
+	if (flags & XDP_USE_NEED_WAKEUP)
+		pool->uses_need_wakeup = true;
+	/* Tx needs to be explicitly woken up the first time.  Also
+	 * for supporting drivers that do not implement this
+	 * feature. They will always have to call sendto() or poll().
+	 */
+	pool->cached_need_wakeup = XDP_WAKEUP_TX;
+
+	dev_hold(netdev);
+
+	if (force_copy)
+		/* For copy-mode, we are done. */
+		return 0;
+
+	if (!netdev->netdev_ops->ndo_bpf ||
+	    !netdev->netdev_ops->ndo_xsk_wakeup) {
+		err = -EOPNOTSUPP;
+		goto err_unreg_pool;
+	}
+
+	bpf.command = XDP_SETUP_XSK_POOL;
+	bpf.xsk.pool = pool;
+	bpf.xsk.queue_id = queue_id;
+
+	err = netdev->netdev_ops->ndo_bpf(netdev, &bpf);
+	if (err)
+		goto err_unreg_pool;
+
+	if (!pool->dma_pages) {
+		WARN(1, "Driver did not DMA map zero-copy buffers");
+		err = -EINVAL;
+		goto err_unreg_xsk;
+	}
+	pool->umem->zc = true;
+	return 0;
+
+err_unreg_xsk:
+	xp_disable_drv_zc(pool);
+err_unreg_pool:
+	if (!force_zc)
+		err = 0; /* fallback to copy mode */
+	if (err) {
+		xsk_clear_pool_at_qid(netdev, queue_id);
+		dev_put(netdev);
+	}
+	return err;
+}
+
+int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs,
+			 struct net_device *dev, u16 queue_id)
+{
+	u16 flags;
+	struct xdp_umem *umem = umem_xs->umem;
+
+	/* One fill and completion ring required for each queue id. */
+	if (!pool->fq || !pool->cq)
+		return -EINVAL;
+
+	flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY;
+	if (umem_xs->pool->uses_need_wakeup)
+		flags |= XDP_USE_NEED_WAKEUP;
+
+	return xp_assign_dev(pool, dev, queue_id, flags);
+}
+
+void xp_clear_dev(struct xsk_buff_pool *pool)
+{
+	if (!pool->netdev)
+		return;
+
+	xp_disable_drv_zc(pool);
+	xsk_clear_pool_at_qid(pool->netdev, pool->queue_id);
+	dev_put(pool->netdev);
+	pool->netdev = NULL;
+}
+
+static void xp_release_deferred(struct work_struct *work)
+{
+	struct xsk_buff_pool *pool = container_of(work, struct xsk_buff_pool,
+						  work);
+
+	rtnl_lock();
+	xp_clear_dev(pool);
+	rtnl_unlock();
+
+	if (pool->fq) {
+		xskq_destroy(pool->fq);
+		pool->fq = NULL;
+	}
+
+	if (pool->cq) {
+		xskq_destroy(pool->cq);
+		pool->cq = NULL;
+	}
+
+	xdp_put_umem(pool->umem, false);
+	xp_destroy(pool);
+}
+
+void xp_get_pool(struct xsk_buff_pool *pool)
+{
+	refcount_inc(&pool->users);
+}
+
+bool xp_put_pool(struct xsk_buff_pool *pool)
+{
+	if (!pool)
+		return false;
+
+	if (refcount_dec_and_test(&pool->users)) {
+		INIT_WORK(&pool->work, xp_release_deferred);
+		schedule_work(&pool->work);
+		return true;
+	}
+
+	return false;
+}
+
+static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool)
+{
+	struct xsk_dma_map *dma_map;
+
+	list_for_each_entry(dma_map, &pool->umem->xsk_dma_list, list) {
+		if (dma_map->netdev == pool->netdev)
+			return dma_map;
+	}
+
+	return NULL;
+}
+
+static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_device *netdev,
+					     u32 nr_pages, struct xdp_umem *umem)
+{
+	struct xsk_dma_map *dma_map;
+
+	dma_map = kzalloc(sizeof(*dma_map), GFP_KERNEL);
+	if (!dma_map)
+		return NULL;
+
+	dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL);
+	if (!dma_map->dma_pages) {
+		kfree(dma_map);
+		return NULL;
+	}
+
+	dma_map->netdev = netdev;
+	dma_map->dev = dev;
+	dma_map->dma_need_sync = false;
+	dma_map->dma_pages_cnt = nr_pages;
+	refcount_set(&dma_map->users, 1);
+	list_add(&dma_map->list, &umem->xsk_dma_list);
+	return dma_map;
+}
+
+static void xp_destroy_dma_map(struct xsk_dma_map *dma_map)
+{
+	list_del(&dma_map->list);
+	kvfree(dma_map->dma_pages);
+	kfree(dma_map);
+}
+
+static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs)
+{
+	dma_addr_t *dma;
+	u32 i;
+
+	for (i = 0; i < dma_map->dma_pages_cnt; i++) {
+		dma = &dma_map->dma_pages[i];
+		if (*dma) {
+			*dma &= ~XSK_NEXT_PG_CONTIG_MASK;
+			dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE,
+					     DMA_BIDIRECTIONAL, attrs);
+			*dma = 0;
+		}
+	}
+
+	xp_destroy_dma_map(dma_map);
+}
+
+void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs)
+{
+	struct xsk_dma_map *dma_map;
+
+	if (pool->dma_pages_cnt == 0)
+		return;
+
+	dma_map = xp_find_dma_map(pool);
+	if (!dma_map) {
+		WARN(1, "Could not find dma_map for device");
+		return;
+	}
+
+	if (!refcount_dec_and_test(&dma_map->users))
+		return;
+
+	__xp_dma_unmap(dma_map, attrs);
+	kvfree(pool->dma_pages);
+	pool->dma_pages_cnt = 0;
+	pool->dev = NULL;
+}
+EXPORT_SYMBOL(xp_dma_unmap);
+
+static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map)
+{
+	u32 i;
+
+	for (i = 0; i < dma_map->dma_pages_cnt - 1; i++) {
+		if (dma_map->dma_pages[i] + PAGE_SIZE == dma_map->dma_pages[i + 1])
+			dma_map->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK;
+		else
+			dma_map->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK;
+	}
+}
+
+static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map)
+{
+	if (!pool->unaligned) {
+		u32 i;
+
+		for (i = 0; i < pool->heads_cnt; i++) {
+			struct xdp_buff_xsk *xskb = &pool->heads[i];
+
+			xp_init_xskb_dma(xskb, pool, dma_map->dma_pages, xskb->orig_addr);
+		}
+	}
+
+	pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL);
+	if (!pool->dma_pages)
+		return -ENOMEM;
+
+	pool->dev = dma_map->dev;
+	pool->dma_pages_cnt = dma_map->dma_pages_cnt;
+	pool->dma_need_sync = dma_map->dma_need_sync;
+	memcpy(pool->dma_pages, dma_map->dma_pages,
+	       pool->dma_pages_cnt * sizeof(*pool->dma_pages));
+
+	return 0;
+}
+
+int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
+	       unsigned long attrs, struct page **pages, u32 nr_pages)
+{
+	struct xsk_dma_map *dma_map;
+	dma_addr_t dma;
+	int err;
+	u32 i;
+
+	dma_map = xp_find_dma_map(pool);
+	if (dma_map) {
+		err = xp_init_dma_info(pool, dma_map);
+		if (err)
+			return err;
+
+		refcount_inc(&dma_map->users);
+		return 0;
+	}
+
+	dma_map = xp_create_dma_map(dev, pool->netdev, nr_pages, pool->umem);
+	if (!dma_map)
+		return -ENOMEM;
+
+	for (i = 0; i < dma_map->dma_pages_cnt; i++) {
+		dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE,
+					 DMA_BIDIRECTIONAL, attrs);
+		if (dma_mapping_error(dev, dma)) {
+			__xp_dma_unmap(dma_map, attrs);
+			return -ENOMEM;
+		}
+		if (dma_need_sync(dev, dma))
+			dma_map->dma_need_sync = true;
+		dma_map->dma_pages[i] = dma;
+	}
+
+	if (pool->unaligned)
+		xp_check_dma_contiguity(dma_map);
+
+	err = xp_init_dma_info(pool, dma_map);
+	if (err) {
+		__xp_dma_unmap(dma_map, attrs);
+		return err;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(xp_dma_map);
+
+static bool xp_addr_crosses_non_contig_pg(struct xsk_buff_pool *pool,
+					  u64 addr)
+{
+	return xp_desc_crosses_non_contig_pg(pool, addr, pool->chunk_size);
+}
+
+static bool xp_check_unaligned(struct xsk_buff_pool *pool, u64 *addr)
+{
+	*addr = xp_unaligned_extract_addr(*addr);
+	if (*addr >= pool->addrs_cnt ||
+	    *addr + pool->chunk_size > pool->addrs_cnt ||
+	    xp_addr_crosses_non_contig_pg(pool, *addr))
+		return false;
+	return true;
+}
+
+static bool xp_check_aligned(struct xsk_buff_pool *pool, u64 *addr)
+{
+	*addr = xp_aligned_extract_addr(pool, *addr);
+	return *addr < pool->addrs_cnt;
+}
+
+static struct xdp_buff_xsk *__xp_alloc(struct xsk_buff_pool *pool)
+{
+	struct xdp_buff_xsk *xskb;
+	u64 addr;
+	bool ok;
+
+	if (pool->free_heads_cnt == 0)
+		return NULL;
+
+	for (;;) {
+		if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) {
+			pool->fq->queue_empty_descs++;
+			return NULL;
+		}
+
+		ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
+		     xp_check_aligned(pool, &addr);
+		if (!ok) {
+			pool->fq->invalid_descs++;
+			xskq_cons_release(pool->fq);
+			continue;
+		}
+		break;
+	}
+
+	if (pool->unaligned) {
+		xskb = pool->free_heads[--pool->free_heads_cnt];
+		xp_init_xskb_addr(xskb, pool, addr);
+		if (pool->dma_pages_cnt)
+			xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr);
+	} else {
+		xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)];
+	}
+
+	xskq_cons_release(pool->fq);
+	return xskb;
+}
+
+struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool)
+{
+	struct xdp_buff_xsk *xskb;
+
+	if (!pool->free_list_cnt) {
+		xskb = __xp_alloc(pool);
+		if (!xskb)
+			return NULL;
+	} else {
+		pool->free_list_cnt--;
+		xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk,
+					free_list_node);
+		list_del_init(&xskb->free_list_node);
+	}
+
+	xskb->xdp.data = xskb->xdp.data_hard_start + XDP_PACKET_HEADROOM;
+	xskb->xdp.data_meta = xskb->xdp.data;
+
+	if (pool->dma_need_sync) {
+		dma_sync_single_range_for_device(pool->dev, xskb->dma, 0,
+						 pool->frame_len,
+						 DMA_BIDIRECTIONAL);
+	}
+	return &xskb->xdp;
+}
+EXPORT_SYMBOL(xp_alloc);
+
+static u32 xp_alloc_new_from_fq(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
+{
+	u32 i, cached_cons, nb_entries;
+
+	if (max > pool->free_heads_cnt)
+		max = pool->free_heads_cnt;
+	max = xskq_cons_nb_entries(pool->fq, max);
+
+	cached_cons = pool->fq->cached_cons;
+	nb_entries = max;
+	i = max;
+	while (i--) {
+		struct xdp_buff_xsk *xskb;
+		u64 addr;
+		bool ok;
+
+		__xskq_cons_read_addr_unchecked(pool->fq, cached_cons++, &addr);
+
+		ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
+			xp_check_aligned(pool, &addr);
+		if (unlikely(!ok)) {
+			pool->fq->invalid_descs++;
+			nb_entries--;
+			continue;
+		}
+
+		if (pool->unaligned) {
+			xskb = pool->free_heads[--pool->free_heads_cnt];
+			xp_init_xskb_addr(xskb, pool, addr);
+			if (pool->dma_pages_cnt)
+				xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr);
+		} else {
+			xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)];
+		}
+
+		*xdp = &xskb->xdp;
+		xdp++;
+	}
+
+	xskq_cons_release_n(pool->fq, max);
+	return nb_entries;
+}
+
+static u32 xp_alloc_reused(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 nb_entries)
+{
+	struct xdp_buff_xsk *xskb;
+	u32 i;
+
+	nb_entries = min_t(u32, nb_entries, pool->free_list_cnt);
+
+	i = nb_entries;
+	while (i--) {
+		xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk, free_list_node);
+		list_del_init(&xskb->free_list_node);
+
+		*xdp = &xskb->xdp;
+		xdp++;
+	}
+	pool->free_list_cnt -= nb_entries;
+
+	return nb_entries;
+}
+
+u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
+{
+	u32 nb_entries1 = 0, nb_entries2;
+
+	if (unlikely(pool->dma_need_sync)) {
+		struct xdp_buff *buff;
+
+		/* Slow path */
+		buff = xp_alloc(pool);
+		if (buff)
+			*xdp = buff;
+		return !!buff;
+	}
+
+	if (unlikely(pool->free_list_cnt)) {
+		nb_entries1 = xp_alloc_reused(pool, xdp, max);
+		if (nb_entries1 == max)
+			return nb_entries1;
+
+		max -= nb_entries1;
+		xdp += nb_entries1;
+	}
+
+	nb_entries2 = xp_alloc_new_from_fq(pool, xdp, max);
+	if (!nb_entries2)
+		pool->fq->queue_empty_descs++;
+
+	return nb_entries1 + nb_entries2;
+}
+EXPORT_SYMBOL(xp_alloc_batch);
+
+bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count)
+{
+	if (pool->free_list_cnt >= count)
+		return true;
+	return xskq_cons_has_entries(pool->fq, count - pool->free_list_cnt);
+}
+EXPORT_SYMBOL(xp_can_alloc);
+
+void xp_free(struct xdp_buff_xsk *xskb)
+{
+	if (!list_empty(&xskb->free_list_node))
+		return;
+
+	xskb->pool->free_list_cnt++;
+	list_add(&xskb->free_list_node, &xskb->pool->free_list);
+}
+EXPORT_SYMBOL(xp_free);
+
+void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
+{
+	addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
+	return pool->addrs + addr;
+}
+EXPORT_SYMBOL(xp_raw_get_data);
+
+dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr)
+{
+	addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
+	return (pool->dma_pages[addr >> PAGE_SHIFT] &
+		~XSK_NEXT_PG_CONTIG_MASK) +
+		(addr & ~PAGE_MASK);
+}
+EXPORT_SYMBOL(xp_raw_get_dma);
+
+void xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk *xskb)
+{
+	dma_sync_single_range_for_cpu(xskb->pool->dev, xskb->dma, 0,
+				      xskb->pool->frame_len, DMA_BIDIRECTIONAL);
+}
+EXPORT_SYMBOL(xp_dma_sync_for_cpu_slow);
+
+void xp_dma_sync_for_device_slow(struct xsk_buff_pool *pool, dma_addr_t dma,
+				 size_t size)
+{
+	dma_sync_single_range_for_device(pool->dev, dma, 0,
+					 size, DMA_BIDIRECTIONAL);
+}
+EXPORT_SYMBOL(xp_dma_sync_for_device_slow);