xsk: Remove MEM_TYPE_ZERO_COPY and corresponding code

There are no users of MEM_TYPE_ZERO_COPY. Remove all corresponding
code, including the "handle" member of struct xdp_buff.

rfc->v1: Fixed spelling in commit message. (Björn)

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200520192103.355233-13-bjorn.topel@gmail.com

6 files changed, 14 insertions, 306 deletions

diff --git a/net/core/xdp.c b/net/core/xdp.c
index f0ce8b195193..a8c2f243367d 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -110,27 +110,6 @@ static void mem_allocator_disconnect(void *allocator)
 	mutex_unlock(&mem_id_lock);
 }
 
-static void mem_id_disconnect(int id)
-{
-	struct xdp_mem_allocator *xa;
-
-	mutex_lock(&mem_id_lock);
-
-	xa = rhashtable_lookup_fast(mem_id_ht, &id, mem_id_rht_params);
-	if (!xa) {
-		mutex_unlock(&mem_id_lock);
-		WARN(1, "Request remove non-existing id(%d), driver bug?", id);
-		return;
-	}
-
-	trace_mem_disconnect(xa);
-
-	if (!rhashtable_remove_fast(mem_id_ht, &xa->node, mem_id_rht_params))
-		call_rcu(&xa->rcu, __xdp_mem_allocator_rcu_free);
-
-	mutex_unlock(&mem_id_lock);
-}
-
 void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq)
 {
 	struct xdp_mem_allocator *xa;
@@ -144,9 +123,6 @@ void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq)
 	if (id == 0)
 		return;
 
-	if (xdp_rxq->mem.type == MEM_TYPE_ZERO_COPY)
-		return mem_id_disconnect(id);
-
 	if (xdp_rxq->mem.type == MEM_TYPE_PAGE_POOL) {
 		rcu_read_lock();
 		xa = rhashtable_lookup(mem_id_ht, &id, mem_id_rht_params);
@@ -302,7 +278,7 @@ int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq,
 	xdp_rxq->mem.type = type;
 
 	if (!allocator) {
-		if (type == MEM_TYPE_PAGE_POOL || type == MEM_TYPE_ZERO_COPY)
+		if (type == MEM_TYPE_PAGE_POOL)
 			return -EINVAL; /* Setup time check page_pool req */
 		return 0;
 	}
@@ -362,7 +338,7 @@ EXPORT_SYMBOL_GPL(xdp_rxq_info_reg_mem_model);
  * of xdp_frames/pages in those cases.
  */
 static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
-			 unsigned long handle, struct xdp_buff *xdp)
+			 struct xdp_buff *xdp)
 {
 	struct xdp_mem_allocator *xa;
 	struct page *page;
@@ -384,14 +360,6 @@ static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
 		page = virt_to_page(data); /* Assumes order0 page*/
 		put_page(page);
 		break;
-	case MEM_TYPE_ZERO_COPY:
-		/* NB! Only valid from an xdp_buff! */
-		rcu_read_lock();
-		/* mem->id is valid, checked in xdp_rxq_info_reg_mem_model() */
-		xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
-		xa->zc_alloc->free(xa->zc_alloc, handle);
-		rcu_read_unlock();
-		break;
 	case MEM_TYPE_XSK_BUFF_POOL:
 		/* NB! Only valid from an xdp_buff! */
 		xsk_buff_free(xdp);
@@ -404,19 +372,19 @@ static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
 
 void xdp_return_frame(struct xdp_frame *xdpf)
 {
-	__xdp_return(xdpf->data, &xdpf->mem, false, 0, NULL);
+	__xdp_return(xdpf->data, &xdpf->mem, false, NULL);
 }
 EXPORT_SYMBOL_GPL(xdp_return_frame);
 
 void xdp_return_frame_rx_napi(struct xdp_frame *xdpf)
 {
-	__xdp_return(xdpf->data, &xdpf->mem, true, 0, NULL);
+	__xdp_return(xdpf->data, &xdpf->mem, true, NULL);
 }
 EXPORT_SYMBOL_GPL(xdp_return_frame_rx_napi);
 
 void xdp_return_buff(struct xdp_buff *xdp)
 {
-	__xdp_return(xdp->data, &xdp->rxq->mem, true, xdp->handle, xdp);
+	__xdp_return(xdp->data, &xdp->rxq->mem, true, xdp);
 }
 EXPORT_SYMBOL_GPL(xdp_return_buff);
 
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
index 7f04688045d5..19e59d1a5e9f 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -179,37 +179,6 @@ void xdp_umem_clear_dev(struct xdp_umem *umem)
 	umem->zc = false;
 }
 
-static void xdp_umem_unmap_pages(struct xdp_umem *umem)
-{
-	unsigned int i;
-
-	for (i = 0; i < umem->npgs; i++)
-		if (PageHighMem(umem->pgs[i]))
-			vunmap(umem->pages[i].addr);
-}
-
-static int xdp_umem_map_pages(struct xdp_umem *umem)
-{
-	unsigned int i;
-	void *addr;
-
-	for (i = 0; i < umem->npgs; i++) {
-		if (PageHighMem(umem->pgs[i]))
-			addr = vmap(&umem->pgs[i], 1, VM_MAP, PAGE_KERNEL);
-		else
-			addr = page_address(umem->pgs[i]);
-
-		if (!addr) {
-			xdp_umem_unmap_pages(umem);
-			return -ENOMEM;
-		}
-
-		umem->pages[i].addr = addr;
-	}
-
-	return 0;
-}
-
 static void xdp_umem_unpin_pages(struct xdp_umem *umem)
 {
 	unpin_user_pages_dirty_lock(umem->pgs, umem->npgs, true);
@@ -244,14 +213,9 @@ static void xdp_umem_release(struct xdp_umem *umem)
 		umem->cq = NULL;
 	}
 
-	xsk_reuseq_destroy(umem);
 	xp_destroy(umem->pool);
-	xdp_umem_unmap_pages(umem);
 	xdp_umem_unpin_pages(umem);
 
-	kvfree(umem->pages);
-	umem->pages = NULL;
-
 	xdp_umem_unaccount_pages(umem);
 	kfree(umem);
 }
@@ -385,11 +349,8 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
 	if (headroom >= chunk_size - XDP_PACKET_HEADROOM)
 		return -EINVAL;
 
-	umem->chunk_mask = unaligned_chunks ? XSK_UNALIGNED_BUF_ADDR_MASK
-					    : ~((u64)chunk_size - 1);
 	umem->size = size;
 	umem->headroom = headroom;
-	umem->chunk_size_nohr = chunk_size - headroom;
 	umem->chunk_size = chunk_size;
 	umem->npgs = size / PAGE_SIZE;
 	umem->pgs = NULL;
@@ -408,29 +369,14 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
 	if (err)
 		goto out_account;
 
-	umem->pages = kvcalloc(umem->npgs, sizeof(*umem->pages),
-			       GFP_KERNEL_ACCOUNT);
-	if (!umem->pages) {
-		err = -ENOMEM;
-		goto out_pin;
-	}
-
-	err = xdp_umem_map_pages(umem);
-	if (err)
-		goto out_pages;
-
 	umem->pool = xp_create(umem->pgs, umem->npgs, chunks, chunk_size,
 			       headroom, size, unaligned_chunks);
 	if (!umem->pool) {
 		err = -ENOMEM;
-		goto out_unmap;
+		goto out_pin;
 	}
 	return 0;
 
-out_unmap:
-	xdp_umem_unmap_pages(umem);
-out_pages:
-	kvfree(umem->pages);
 out_pin:
 	xdp_umem_unpin_pages(umem);
 out_account:
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 6933f0d494ba..3f2ab732ab8b 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -39,24 +39,6 @@ bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs)
 		READ_ONCE(xs->umem->fq);
 }
 
-bool xsk_umem_has_addrs(struct xdp_umem *umem, u32 cnt)
-{
-	return xskq_cons_has_entries(umem->fq, cnt);
-}
-EXPORT_SYMBOL(xsk_umem_has_addrs);
-
-bool xsk_umem_peek_addr(struct xdp_umem *umem, u64 *addr)
-{
-	return xskq_cons_peek_addr(umem->fq, addr, umem);
-}
-EXPORT_SYMBOL(xsk_umem_peek_addr);
-
-void xsk_umem_release_addr(struct xdp_umem *umem)
-{
-	xskq_cons_release(umem->fq);
-}
-EXPORT_SYMBOL(xsk_umem_release_addr);
-
 void xsk_set_rx_need_wakeup(struct xdp_umem *umem)
 {
 	if (umem->need_wakeup & XDP_WAKEUP_RX)
@@ -203,8 +185,7 @@ static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp,
 
 	len = xdp->data_end - xdp->data;
 
-	return xdp->rxq->mem.type == MEM_TYPE_ZERO_COPY ||
-		xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL ?
+	return xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL ?
 		__xsk_rcv_zc(xs, xdp, len) :
 		__xsk_rcv(xs, xdp, len, explicit_free);
 }
@@ -588,24 +569,6 @@ static struct socket *xsk_lookup_xsk_from_fd(int fd)
 	return sock;
 }
 
-/* Check if umem pages are contiguous.
- * If zero-copy mode, use the DMA address to do the page contiguity check
- * For all other modes we use addr (kernel virtual address)
- * Store the result in the low bits of addr.
- */
-static void xsk_check_page_contiguity(struct xdp_umem *umem, u32 flags)
-{
-	struct xdp_umem_page *pgs = umem->pages;
-	int i, is_contig;
-
-	for (i = 0; i < umem->npgs - 1; i++) {
-		is_contig = (flags & XDP_ZEROCOPY) ?
-			(pgs[i].dma + PAGE_SIZE == pgs[i + 1].dma) :
-			(pgs[i].addr + PAGE_SIZE == pgs[i + 1].addr);
-		pgs[i].addr += is_contig << XSK_NEXT_PG_CONTIG_SHIFT;
-	}
-}
-
 static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 {
 	struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr;
@@ -688,23 +651,14 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 		goto out_unlock;
 	} else {
 		/* This xsk has its own umem. */
-		xskq_set_umem(xs->umem->fq, xs->umem->size,
-			      xs->umem->chunk_mask);
-		xskq_set_umem(xs->umem->cq, xs->umem->size,
-			      xs->umem->chunk_mask);
-
 		err = xdp_umem_assign_dev(xs->umem, dev, qid, flags);
 		if (err)
 			goto out_unlock;
-
-		xsk_check_page_contiguity(xs->umem, flags);
 	}
 
 	xs->dev = dev;
 	xs->zc = xs->umem->zc;
 	xs->queue_id = qid;
-	xskq_set_umem(xs->rx, xs->umem->size, xs->umem->chunk_mask);
-	xskq_set_umem(xs->tx, xs->umem->size, xs->umem->chunk_mask);
 	xdp_add_sk_umem(xs->umem, xs);
 
 out_unlock:
diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index e214a5795a62..89dae78865e7 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c
@@ -8,6 +8,13 @@
 
 #include "xsk_queue.h"
 
+/* Masks for xdp_umem_page flags.
+ * The low 12-bits of the addr will be 0 since this is the page address, so we
+ * can use them for flags.
+ */
+#define XSK_NEXT_PG_CONTIG_SHIFT 0
+#define XSK_NEXT_PG_CONTIG_MASK BIT_ULL(XSK_NEXT_PG_CONTIG_SHIFT)
+
 struct xsk_buff_pool {
 	struct xsk_queue *fq;
 	struct list_head free_list;
diff --git a/net/xdp/xsk_queue.c b/net/xdp/xsk_queue.c
index 554b1ebb4d02..6cf9586e5027 100644
--- a/net/xdp/xsk_queue.c
+++ b/net/xdp/xsk_queue.c
@@ -10,15 +10,6 @@
 
 #include "xsk_queue.h"
 
-void xskq_set_umem(struct xsk_queue *q, u64 umem_size, u64 chunk_mask)
-{
-	if (!q)
-		return;
-
-	q->umem_size = umem_size;
-	q->chunk_mask = chunk_mask;
-}
-
 static size_t xskq_get_ring_size(struct xsk_queue *q, bool umem_queue)
 {
 	struct xdp_umem_ring *umem_ring;
@@ -64,56 +55,3 @@ void xskq_destroy(struct xsk_queue *q)
 	page_frag_free(q->ring);
 	kfree(q);
 }
-
-struct xdp_umem_fq_reuse *xsk_reuseq_prepare(u32 nentries)
-{
-	struct xdp_umem_fq_reuse *newq;
-
-	/* Check for overflow */
-	if (nentries > (u32)roundup_pow_of_two(nentries))
-		return NULL;
-	nentries = roundup_pow_of_two(nentries);
-
-	newq = kvmalloc(struct_size(newq, handles, nentries), GFP_KERNEL);
-	if (!newq)
-		return NULL;
-	memset(newq, 0, offsetof(typeof(*newq), handles));
-
-	newq->nentries = nentries;
-	return newq;
-}
-EXPORT_SYMBOL_GPL(xsk_reuseq_prepare);
-
-struct xdp_umem_fq_reuse *xsk_reuseq_swap(struct xdp_umem *umem,
-					  struct xdp_umem_fq_reuse *newq)
-{
-	struct xdp_umem_fq_reuse *oldq = umem->fq_reuse;
-
-	if (!oldq) {
-		umem->fq_reuse = newq;
-		return NULL;
-	}
-
-	if (newq->nentries < oldq->length)
-		return newq;
-
-	memcpy(newq->handles, oldq->handles,
-	       array_size(oldq->length, sizeof(u64)));
-	newq->length = oldq->length;
-
-	umem->fq_reuse = newq;
-	return oldq;
-}
-EXPORT_SYMBOL_GPL(xsk_reuseq_swap);
-
-void xsk_reuseq_free(struct xdp_umem_fq_reuse *rq)
-{
-	kvfree(rq);
-}
-EXPORT_SYMBOL_GPL(xsk_reuseq_free);
-
-void xsk_reuseq_destroy(struct xdp_umem *umem)
-{
-	xsk_reuseq_free(umem->fq_reuse);
-	umem->fq_reuse = NULL;
-}
diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
index 9151aef7dbca..16bf15864788 100644
--- a/net/xdp/xsk_queue.h
+++ b/net/xdp/xsk_queue.h
@@ -32,8 +32,6 @@ struct xdp_umem_ring {
 };
 
 struct xsk_queue {
-	u64 chunk_mask;
-	u64 umem_size;
 	u32 ring_mask;
 	u32 nentries;
 	u32 cached_prod;
@@ -106,90 +104,6 @@ struct xsk_queue {
 
 /* Functions that read and validate content from consumer rings. */
 
-static inline bool xskq_cons_crosses_non_contig_pg(struct xdp_umem *umem,
-						   u64 addr,
-						   u64 length)
-{
-	bool cross_pg = (addr & (PAGE_SIZE - 1)) + length > PAGE_SIZE;
-	bool next_pg_contig =
-		(unsigned long)umem->pages[(addr >> PAGE_SHIFT)].addr &
-			XSK_NEXT_PG_CONTIG_MASK;
-
-	return cross_pg && !next_pg_contig;
-}
-
-static inline bool xskq_cons_is_valid_unaligned(struct xsk_queue *q,
-						u64 addr,
-						u64 length,
-						struct xdp_umem *umem)
-{
-	u64 base_addr = xsk_umem_extract_addr(addr);
-
-	addr = xsk_umem_add_offset_to_addr(addr);
-	if (base_addr >= q->umem_size || addr >= q->umem_size ||
-	    xskq_cons_crosses_non_contig_pg(umem, addr, length)) {
-		q->invalid_descs++;
-		return false;
-	}
-
-	return true;
-}
-
-static inline bool xskq_cons_is_valid_addr(struct xsk_queue *q, u64 addr)
-{
-	if (addr >= q->umem_size) {
-		q->invalid_descs++;
-		return false;
-	}
-
-	return true;
-}
-
-static inline bool xskq_cons_read_addr(struct xsk_queue *q, u64 *addr,
-				       struct xdp_umem *umem)
-{
-	struct xdp_umem_ring *ring = (struct xdp_umem_ring *)q->ring;
-
-	while (q->cached_cons != q->cached_prod) {
-		u32 idx = q->cached_cons & q->ring_mask;
-
-		*addr = ring->desc[idx] & q->chunk_mask;
-
-		if (umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG) {
-			if (xskq_cons_is_valid_unaligned(q, *addr,
-							 umem->chunk_size_nohr,
-							 umem))
-				return true;
-			goto out;
-		}
-
-		if (xskq_cons_is_valid_addr(q, *addr))
-			return true;
-
-out:
-		q->cached_cons++;
-	}
-
-	return false;
-}
-
-static inline bool xskq_cons_read_addr_aligned(struct xsk_queue *q, u64 *addr)
-{
-	struct xdp_umem_ring *ring = (struct xdp_umem_ring *)q->ring;
-
-	while (q->cached_cons != q->cached_prod) {
-		u32 idx = q->cached_cons & q->ring_mask;
-
-		*addr = ring->desc[idx];
-		if (xskq_cons_is_valid_addr(q, *addr))
-			return true;
-
-		q->cached_cons++;
-	}
-
-	return false;
-}
-
 static inline bool xskq_cons_read_addr_unchecked(struct xsk_queue *q, u64 *addr)
 {
 	struct xdp_umem_ring *ring = (struct xdp_umem_ring *)q->ring;
@@ -267,21 +181,6 @@ static inline bool xskq_cons_has_entries(struct xsk_queue *q, u32 cnt)
 	return entries >= cnt;
 }
 
-static inline bool xskq_cons_peek_addr(struct xsk_queue *q, u64 *addr,
-				       struct xdp_umem *umem)
-{
-	if (q->cached_prod == q->cached_cons)
-		xskq_cons_get_entries(q);
-	return xskq_cons_read_addr(q, addr, umem);
-}
-
-static inline bool xskq_cons_peek_addr_aligned(struct xsk_queue *q, u64 *addr)
-{
-	if (q->cached_prod == q->cached_cons)
-		xskq_cons_get_entries(q);
-	return xskq_cons_read_addr_aligned(q, addr);
-}
-
 static inline bool xskq_cons_peek_addr_unchecked(struct xsk_queue *q, u64 *addr)
 {
 	if (q->cached_prod == q->cached_cons)
@@ -410,11 +309,7 @@ static inline u64 xskq_nb_invalid_descs(struct xsk_queue *q)
 	return q ? q->invalid_descs : 0;
 }
 
-void xskq_set_umem(struct xsk_queue *q, u64 umem_size, u64 chunk_mask);
 struct xsk_queue *xskq_create(u32 nentries, bool umem_queue);
 void xskq_destroy(struct xsk_queue *q_ops);
 
-/* Executed by the core when the entire UMEM gets freed */
-void xsk_reuseq_destroy(struct xdp_umem *umem);
-
 #endif /* _LINUX_XSK_QUEUE_H */