diff options
| -rw-r--r-- | io_uring/zcrx.c | 274 | ||||
| -rw-r--r-- | io_uring/zcrx.h | 3 |
2 files changed, 277 insertions, 0 deletions
diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c index 435cd634f91c..f9e924cfa829 100644 --- a/io_uring/zcrx.c +++ b/io_uring/zcrx.c @@ -2,10 +2,17 @@ #include <linux/kernel.h> #include <linux/errno.h> #include <linux/mm.h> +#include <linux/nospec.h> #include <linux/io_uring.h> #include <linux/netdevice.h> #include <linux/rtnetlink.h> +#include <net/page_pool/helpers.h> +#include <net/page_pool/memory_provider.h> +#include <net/netlink.h> + +#include <trace/events/page_pool.h> + #include <uapi/linux/io_uring.h> #include "io_uring.h" @@ -16,6 +23,33 @@ #define IO_RQ_MAX_ENTRIES 32768 +__maybe_unused +static const struct memory_provider_ops io_uring_pp_zc_ops; + +static inline struct io_zcrx_area *io_zcrx_iov_to_area(const struct net_iov *niov) +{ + struct net_iov_area *owner = net_iov_owner(niov); + + return container_of(owner, struct io_zcrx_area, nia); +} + +static inline atomic_t *io_get_user_counter(struct net_iov *niov) +{ + struct io_zcrx_area *area = io_zcrx_iov_to_area(niov); + + return &area->user_refs[net_iov_idx(niov)]; +} + +static bool io_zcrx_put_niov_uref(struct net_iov *niov) +{ + atomic_t *uref = io_get_user_counter(niov); + + if (unlikely(!atomic_read(uref))) + return false; + atomic_dec(uref); + return true; +} + static int io_allocate_rbuf_ring(struct io_zcrx_ifq *ifq, struct io_uring_zcrx_ifq_reg *reg, struct io_uring_region_desc *rd) @@ -51,6 +85,7 @@ static void io_zcrx_free_area(struct io_zcrx_area *area) { kvfree(area->freelist); kvfree(area->nia.niovs); + kvfree(area->user_refs); if (area->pages) { unpin_user_pages(area->pages, area->nia.num_niovs); kvfree(area->pages); @@ -106,6 +141,19 @@ static int io_zcrx_create_area(struct io_zcrx_ifq *ifq, for (i = 0; i < nr_pages; i++) area->freelist[i] = i; + area->user_refs = kvmalloc_array(nr_pages, sizeof(area->user_refs[0]), + GFP_KERNEL | __GFP_ZERO); + if (!area->user_refs) + goto err; + + for (i = 0; i < nr_pages; i++) { + struct net_iov *niov = &area->nia.niovs[i]; + + niov->owner = &area->nia; + area->freelist[i] = i; + atomic_set(&area->user_refs[i], 0); + } + area->free_count = nr_pages; area->ifq = ifq; /* we're only supporting one area per ifq for now */ @@ -131,6 +179,7 @@ static struct io_zcrx_ifq *io_zcrx_ifq_alloc(struct io_ring_ctx *ctx) ifq->if_rxq = -1; ifq->ctx = ctx; spin_lock_init(&ifq->lock); + spin_lock_init(&ifq->rq_lock); return ifq; } @@ -256,7 +305,232 @@ void io_unregister_zcrx_ifqs(struct io_ring_ctx *ctx) io_zcrx_ifq_free(ifq); } +static struct net_iov *__io_zcrx_get_free_niov(struct io_zcrx_area *area) +{ + unsigned niov_idx; + + lockdep_assert_held(&area->freelist_lock); + + niov_idx = area->freelist[--area->free_count]; + return &area->nia.niovs[niov_idx]; +} + +static void io_zcrx_return_niov_freelist(struct net_iov *niov) +{ + struct io_zcrx_area *area = io_zcrx_iov_to_area(niov); + + spin_lock_bh(&area->freelist_lock); + area->freelist[area->free_count++] = net_iov_idx(niov); + spin_unlock_bh(&area->freelist_lock); +} + +static void io_zcrx_return_niov(struct net_iov *niov) +{ + netmem_ref netmem = net_iov_to_netmem(niov); + + page_pool_put_unrefed_netmem(niov->pp, netmem, -1, false); +} + +static void io_zcrx_scrub(struct io_zcrx_ifq *ifq) +{ + struct io_zcrx_area *area = ifq->area; + int i; + + if (!area) + return; + + /* Reclaim back all buffers given to the user space. */ + for (i = 0; i < area->nia.num_niovs; i++) { + struct net_iov *niov = &area->nia.niovs[i]; + int nr; + + if (!atomic_read(io_get_user_counter(niov))) + continue; + nr = atomic_xchg(io_get_user_counter(niov), 0); + if (nr && !page_pool_unref_netmem(net_iov_to_netmem(niov), nr)) + io_zcrx_return_niov(niov); + } +} + void io_shutdown_zcrx_ifqs(struct io_ring_ctx *ctx) { lockdep_assert_held(&ctx->uring_lock); + + if (ctx->ifq) + io_zcrx_scrub(ctx->ifq); +} + +static inline u32 io_zcrx_rqring_entries(struct io_zcrx_ifq *ifq) +{ + u32 entries; + + entries = smp_load_acquire(&ifq->rq_ring->tail) - ifq->cached_rq_head; + return min(entries, ifq->rq_entries); } + +static struct io_uring_zcrx_rqe *io_zcrx_get_rqe(struct io_zcrx_ifq *ifq, + unsigned mask) +{ + unsigned int idx = ifq->cached_rq_head++ & mask; + + return &ifq->rqes[idx]; +} + +static void io_zcrx_ring_refill(struct page_pool *pp, + struct io_zcrx_ifq *ifq) +{ + unsigned int mask = ifq->rq_entries - 1; + unsigned int entries; + netmem_ref netmem; + + spin_lock_bh(&ifq->rq_lock); + + entries = io_zcrx_rqring_entries(ifq); + entries = min_t(unsigned, entries, PP_ALLOC_CACHE_REFILL - pp->alloc.count); + if (unlikely(!entries)) { + spin_unlock_bh(&ifq->rq_lock); + return; + } + + do { + struct io_uring_zcrx_rqe *rqe = io_zcrx_get_rqe(ifq, mask); + struct io_zcrx_area *area; + struct net_iov *niov; + unsigned niov_idx, area_idx; + + area_idx = rqe->off >> IORING_ZCRX_AREA_SHIFT; + niov_idx = (rqe->off & ~IORING_ZCRX_AREA_MASK) >> PAGE_SHIFT; + + if (unlikely(rqe->__pad || area_idx)) + continue; + area = ifq->area; + + if (unlikely(niov_idx >= area->nia.num_niovs)) + continue; + niov_idx = array_index_nospec(niov_idx, area->nia.num_niovs); + + niov = &area->nia.niovs[niov_idx]; + if (!io_zcrx_put_niov_uref(niov)) + continue; + + netmem = net_iov_to_netmem(niov); + if (page_pool_unref_netmem(netmem, 1) != 0) + continue; + + if (unlikely(niov->pp != pp)) { + io_zcrx_return_niov(niov); + continue; + } + + net_mp_netmem_place_in_cache(pp, netmem); + } while (--entries); + + smp_store_release(&ifq->rq_ring->head, ifq->cached_rq_head); + spin_unlock_bh(&ifq->rq_lock); +} + +static void io_zcrx_refill_slow(struct page_pool *pp, struct io_zcrx_ifq *ifq) +{ + struct io_zcrx_area *area = ifq->area; + + spin_lock_bh(&area->freelist_lock); + while (area->free_count && pp->alloc.count < PP_ALLOC_CACHE_REFILL) { + struct net_iov *niov = __io_zcrx_get_free_niov(area); + netmem_ref netmem = net_iov_to_netmem(niov); + + net_mp_niov_set_page_pool(pp, niov); + net_mp_netmem_place_in_cache(pp, netmem); + } + spin_unlock_bh(&area->freelist_lock); +} + +static netmem_ref io_pp_zc_alloc_netmems(struct page_pool *pp, gfp_t gfp) +{ + struct io_zcrx_ifq *ifq = pp->mp_priv; + + /* pp should already be ensuring that */ + if (unlikely(pp->alloc.count)) + goto out_return; + + io_zcrx_ring_refill(pp, ifq); + if (likely(pp->alloc.count)) + goto out_return; + + io_zcrx_refill_slow(pp, ifq); + if (!pp->alloc.count) + return 0; +out_return: + return pp->alloc.cache[--pp->alloc.count]; +} + +static bool io_pp_zc_release_netmem(struct page_pool *pp, netmem_ref netmem) +{ + struct net_iov *niov; + + if (WARN_ON_ONCE(!netmem_is_net_iov(netmem))) + return false; + + niov = netmem_to_net_iov(netmem); + net_mp_niov_clear_page_pool(niov); + io_zcrx_return_niov_freelist(niov); + return false; +} + +static int io_pp_zc_init(struct page_pool *pp) +{ + struct io_zcrx_ifq *ifq = pp->mp_priv; + + if (WARN_ON_ONCE(!ifq)) + return -EINVAL; + if (pp->dma_map) + return -EOPNOTSUPP; + if (pp->p.order != 0) + return -EOPNOTSUPP; + + percpu_ref_get(&ifq->ctx->refs); + return 0; +} + +static void io_pp_zc_destroy(struct page_pool *pp) +{ + struct io_zcrx_ifq *ifq = pp->mp_priv; + struct io_zcrx_area *area = ifq->area; + + if (WARN_ON_ONCE(area->free_count != area->nia.num_niovs)) + return; + percpu_ref_put(&ifq->ctx->refs); +} + +static int io_pp_nl_fill(void *mp_priv, struct sk_buff *rsp, + struct netdev_rx_queue *rxq) +{ + struct nlattr *nest; + int type; + + type = rxq ? NETDEV_A_QUEUE_IO_URING : NETDEV_A_PAGE_POOL_IO_URING; + nest = nla_nest_start(rsp, type); + if (!nest) + return -EMSGSIZE; + nla_nest_end(rsp, nest); + + return 0; +} + +static void io_pp_uninstall(void *mp_priv, struct netdev_rx_queue *rxq) +{ + struct pp_memory_provider_params *p = &rxq->mp_params; + struct io_zcrx_ifq *ifq = mp_priv; + + io_zcrx_drop_netdev(ifq); + p->mp_ops = NULL; + p->mp_priv = NULL; +} + +static const struct memory_provider_ops io_uring_pp_zc_ops = { + .alloc_netmems = io_pp_zc_alloc_netmems, + .release_netmem = io_pp_zc_release_netmem, + .init = io_pp_zc_init, + .destroy = io_pp_zc_destroy, + .nl_fill = io_pp_nl_fill, + .uninstall = io_pp_uninstall, +}; diff --git a/io_uring/zcrx.h b/io_uring/zcrx.h index 595bca0001d2..6c808240ac91 100644 --- a/io_uring/zcrx.h +++ b/io_uring/zcrx.h @@ -9,6 +9,7 @@ struct io_zcrx_area { struct net_iov_area nia; struct io_zcrx_ifq *ifq; + atomic_t *user_refs; u16 area_id; struct page **pages; @@ -26,6 +27,8 @@ struct io_zcrx_ifq { struct io_uring *rq_ring; struct io_uring_zcrx_rqe *rqes; u32 rq_entries; + u32 cached_rq_head; + spinlock_t rq_lock; u32 if_rxq; struct device *dev; |