ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/net/xdp/xsk_queue.h b/marvell/linux/net/xdp/xsk_queue.h
new file mode 100644
index 0000000..ee3f8c8
--- /dev/null
+++ b/marvell/linux/net/xdp/xsk_queue.h
@@ -0,0 +1,384 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* XDP user-space ring structure
+ * Copyright(c) 2018 Intel Corporation.
+ */
+
+#ifndef _LINUX_XSK_QUEUE_H
+#define _LINUX_XSK_QUEUE_H
+
+#include <linux/types.h>
+#include <linux/if_xdp.h>
+#include <net/xdp_sock.h>
+
+#define RX_BATCH_SIZE 16
+#define LAZY_UPDATE_THRESHOLD 128
+
+struct xdp_ring {
+ u32 producer ____cacheline_aligned_in_smp;
+ u32 consumer ____cacheline_aligned_in_smp;
+ u32 flags;
+};
+
+/* Used for the RX and TX queues for packets */
+struct xdp_rxtx_ring {
+ struct xdp_ring ptrs;
+ struct xdp_desc desc[0] ____cacheline_aligned_in_smp;
+};
+
+/* Used for the fill and completion queues for buffers */
+struct xdp_umem_ring {
+ struct xdp_ring ptrs;
+ u64 desc[0] ____cacheline_aligned_in_smp;
+};
+
+struct xsk_queue {
+ u64 chunk_mask;
+ u64 size;
+ u32 ring_mask;
+ u32 nentries;
+ u32 prod_head;
+ u32 prod_tail;
+ u32 cons_head;
+ u32 cons_tail;
+ struct xdp_ring *ring;
+ u64 invalid_descs;
+};
+
+/* The structure of the shared state of the rings are the same as the
+ * ring buffer in kernel/events/ring_buffer.c. For the Rx and completion
+ * ring, the kernel is the producer and user space is the consumer. For
+ * the Tx and fill rings, the kernel is the consumer and user space is
+ * the producer.
+ *
+ * producer consumer
+ *
+ * if (LOAD ->consumer) { LOAD ->producer
+ * (A) smp_rmb() (C)
+ * STORE $data LOAD $data
+ * smp_wmb() (B) smp_mb() (D)
+ * STORE ->producer STORE ->consumer
+ * }
+ *
+ * (A) pairs with (D), and (B) pairs with (C).
+ *
+ * Starting with (B), it protects the data from being written after
+ * the producer pointer. If this barrier was missing, the consumer
+ * could observe the producer pointer being set and thus load the data
+ * before the producer has written the new data. The consumer would in
+ * this case load the old data.
+ *
+ * (C) protects the consumer from speculatively loading the data before
+ * the producer pointer actually has been read. If we do not have this
+ * barrier, some architectures could load old data as speculative loads
+ * are not discarded as the CPU does not know there is a dependency
+ * between ->producer and data.
+ *
+ * (A) is a control dependency that separates the load of ->consumer
+ * from the stores of $data. In case ->consumer indicates there is no
+ * room in the buffer to store $data we do not. So no barrier is needed.
+ *
+ * (D) protects the load of the data to be observed to happen after the
+ * store of the consumer pointer. If we did not have this memory
+ * barrier, the producer could observe the consumer pointer being set
+ * and overwrite the data with a new value before the consumer got the
+ * chance to read the old value. The consumer would thus miss reading
+ * the old entry and very likely read the new entry twice, once right
+ * now and again after circling through the ring.
+ */
+
+/* Common functions operating for both RXTX and umem queues */
+
+static inline u64 xskq_nb_invalid_descs(struct xsk_queue *q)
+{
+ return q ? q->invalid_descs : 0;
+}
+
+static inline u32 xskq_nb_avail(struct xsk_queue *q, u32 dcnt)
+{
+ u32 entries = q->prod_tail - q->cons_tail;
+
+ if (entries == 0) {
+ /* Refresh the local pointer */
+ q->prod_tail = READ_ONCE(q->ring->producer);
+ entries = q->prod_tail - q->cons_tail;
+ }
+
+ return (entries > dcnt) ? dcnt : entries;
+}
+
+static inline u32 xskq_nb_free(struct xsk_queue *q, u32 producer, u32 dcnt)
+{
+ u32 free_entries = q->nentries - (producer - q->cons_tail);
+
+ if (free_entries >= dcnt)
+ return free_entries;
+
+ /* Refresh the local tail pointer */
+ q->cons_tail = READ_ONCE(q->ring->consumer);
+ return q->nentries - (producer - q->cons_tail);
+}
+
+static inline bool xskq_has_addrs(struct xsk_queue *q, u32 cnt)
+{
+ u32 entries = q->prod_tail - q->cons_tail;
+
+ if (entries >= cnt)
+ return true;
+
+ /* Refresh the local pointer. */
+ q->prod_tail = READ_ONCE(q->ring->producer);
+ entries = q->prod_tail - q->cons_tail;
+
+ return entries >= cnt;
+}
+
+/* UMEM queue */
+
+static inline bool xskq_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_is_valid_addr(struct xsk_queue *q, u64 addr)
+{
+ if (addr >= q->size) {
+ q->invalid_descs++;
+ return false;
+ }
+
+ return true;
+}
+
+static inline bool xskq_is_valid_addr_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->size || addr >= q->size ||
+ xskq_crosses_non_contig_pg(umem, addr, length)) {
+ q->invalid_descs++;
+ return false;
+ }
+
+ return true;
+}
+
+static inline u64 *xskq_validate_addr(struct xsk_queue *q, u64 *addr,
+ struct xdp_umem *umem)
+{
+ while (q->cons_tail != q->cons_head) {
+ struct xdp_umem_ring *ring = (struct xdp_umem_ring *)q->ring;
+ unsigned int idx = q->cons_tail & q->ring_mask;
+
+ *addr = READ_ONCE(ring->desc[idx]) & q->chunk_mask;
+
+ if (umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG) {
+ if (xskq_is_valid_addr_unaligned(q, *addr,
+ umem->chunk_size_nohr,
+ umem))
+ return addr;
+ goto out;
+ }
+
+ if (xskq_is_valid_addr(q, *addr))
+ return addr;
+
+out:
+ q->cons_tail++;
+ }
+
+ return NULL;
+}
+
+static inline u64 *xskq_peek_addr(struct xsk_queue *q, u64 *addr,
+ struct xdp_umem *umem)
+{
+ if (q->cons_tail == q->cons_head) {
+ smp_mb(); /* D, matches A */
+ WRITE_ONCE(q->ring->consumer, q->cons_tail);
+ q->cons_head = q->cons_tail + xskq_nb_avail(q, RX_BATCH_SIZE);
+
+ /* Order consumer and data */
+ smp_rmb();
+ }
+
+ return xskq_validate_addr(q, addr, umem);
+}
+
+static inline void xskq_discard_addr(struct xsk_queue *q)
+{
+ q->cons_tail++;
+}
+
+static inline int xskq_produce_addr(struct xsk_queue *q, u64 addr)
+{
+ struct xdp_umem_ring *ring = (struct xdp_umem_ring *)q->ring;
+
+ if (xskq_nb_free(q, q->prod_tail, 1) == 0)
+ return -ENOSPC;
+
+ /* A, matches D */
+ ring->desc[q->prod_tail++ & q->ring_mask] = addr;
+
+ /* Order producer and data */
+ smp_wmb(); /* B, matches C */
+
+ WRITE_ONCE(q->ring->producer, q->prod_tail);
+ return 0;
+}
+
+static inline int xskq_produce_addr_lazy(struct xsk_queue *q, u64 addr)
+{
+ struct xdp_umem_ring *ring = (struct xdp_umem_ring *)q->ring;
+
+ if (xskq_nb_free(q, q->prod_head, LAZY_UPDATE_THRESHOLD) == 0)
+ return -ENOSPC;
+
+ /* A, matches D */
+ ring->desc[q->prod_head++ & q->ring_mask] = addr;
+ return 0;
+}
+
+static inline void xskq_produce_flush_addr_n(struct xsk_queue *q,
+ u32 nb_entries)
+{
+ /* Order producer and data */
+ smp_wmb(); /* B, matches C */
+
+ q->prod_tail += nb_entries;
+ WRITE_ONCE(q->ring->producer, q->prod_tail);
+}
+
+static inline int xskq_reserve_addr(struct xsk_queue *q)
+{
+ if (xskq_nb_free(q, q->prod_head, 1) == 0)
+ return -ENOSPC;
+
+ /* A, matches D */
+ q->prod_head++;
+ return 0;
+}
+
+/* Rx/Tx queue */
+
+static inline bool xskq_is_valid_desc(struct xsk_queue *q, struct xdp_desc *d,
+ struct xdp_umem *umem)
+{
+ if (umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG) {
+ if (!xskq_is_valid_addr_unaligned(q, d->addr, d->len, umem))
+ return false;
+
+ if (d->len > umem->chunk_size_nohr || d->options) {
+ q->invalid_descs++;
+ return false;
+ }
+
+ return true;
+ }
+
+ if (!xskq_is_valid_addr(q, d->addr))
+ return false;
+
+ if (((d->addr + d->len) & q->chunk_mask) != (d->addr & q->chunk_mask) ||
+ d->options) {
+ q->invalid_descs++;
+ return false;
+ }
+
+ return true;
+}
+
+static inline struct xdp_desc *xskq_validate_desc(struct xsk_queue *q,
+ struct xdp_desc *desc,
+ struct xdp_umem *umem)
+{
+ while (q->cons_tail != q->cons_head) {
+ struct xdp_rxtx_ring *ring = (struct xdp_rxtx_ring *)q->ring;
+ unsigned int idx = q->cons_tail & q->ring_mask;
+
+ *desc = READ_ONCE(ring->desc[idx]);
+ if (xskq_is_valid_desc(q, desc, umem))
+ return desc;
+
+ q->cons_tail++;
+ }
+
+ return NULL;
+}
+
+static inline struct xdp_desc *xskq_peek_desc(struct xsk_queue *q,
+ struct xdp_desc *desc,
+ struct xdp_umem *umem)
+{
+ if (q->cons_tail == q->cons_head) {
+ smp_mb(); /* D, matches A */
+ WRITE_ONCE(q->ring->consumer, q->cons_tail);
+ q->cons_head = q->cons_tail + xskq_nb_avail(q, RX_BATCH_SIZE);
+
+ /* Order consumer and data */
+ smp_rmb(); /* C, matches B */
+ }
+
+ return xskq_validate_desc(q, desc, umem);
+}
+
+static inline void xskq_discard_desc(struct xsk_queue *q)
+{
+ q->cons_tail++;
+}
+
+static inline int xskq_produce_batch_desc(struct xsk_queue *q,
+ u64 addr, u32 len)
+{
+ struct xdp_rxtx_ring *ring = (struct xdp_rxtx_ring *)q->ring;
+ unsigned int idx;
+
+ if (xskq_nb_free(q, q->prod_head, 1) == 0)
+ return -ENOSPC;
+
+ /* A, matches D */
+ idx = (q->prod_head++) & q->ring_mask;
+ ring->desc[idx].addr = addr;
+ ring->desc[idx].len = len;
+
+ return 0;
+}
+
+static inline void xskq_produce_flush_desc(struct xsk_queue *q)
+{
+ /* Order producer and data */
+ smp_wmb(); /* B, matches C */
+
+ q->prod_tail = q->prod_head;
+ WRITE_ONCE(q->ring->producer, q->prod_tail);
+}
+
+static inline bool xskq_full_desc(struct xsk_queue *q)
+{
+ /* No barriers needed since data is not accessed */
+ return READ_ONCE(q->ring->producer) - READ_ONCE(q->ring->consumer) ==
+ q->nentries;
+}
+
+static inline bool xskq_empty_desc(struct xsk_queue *q)
+{
+ /* No barriers needed since data is not accessed */
+ return READ_ONCE(q->ring->consumer) == READ_ONCE(q->ring->producer);
+}
+
+void xskq_set_umem(struct xsk_queue *q, u64 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 */