net/mlx5e: RX, Remove alloc unit layout constraint for legacy rq

The mlx5e_alloc_unit union is conveniently used to store arrays of
pointers to struct page or struct xdp_buff (for xsk). The union is
currently expected to have the size of a pointer for xsk batch
allocations to work. This is conveniet for the current state of the
code but makes it impossible to add a structure of a different size
to the alloc unit.

A further patch in the series will add the mlx5e_frag_page struct for
which the described size constraint will no longer hold.

This change removes the usage of mlx5e_alloc_unit union for legacy rq:

- A union of arrays is introduced (mlx5e_alloc_units) to replace the
  array of unions to allow structures of different sizes.

- Each fragment has a pointer to a unit in the mlx5e_alloc_units array.

Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h
index 02237e6..32036f2 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -606,11 +606,19 @@ struct mlx5e_icosq {
 } ____cacheline_aligned_in_smp;
 
 struct mlx5e_wqe_frag_info {
-       union mlx5e_alloc_unit *au;
+       union {
+               struct page **pagep;
+               struct xdp_buff **xskp;
+       };
        u32 offset;
        bool last_in_page;
 };
 
+union mlx5e_alloc_units {
+       DECLARE_FLEX_ARRAY(struct page *, pages);
+       DECLARE_FLEX_ARRAY(struct xdp_buff *, xsk_buffs);
+};
+
 struct mlx5e_mpw_info {
        u16 consumed_strides;
        DECLARE_BITMAP(xdp_xmit_bitmap, MLX5_MPWRQ_MAX_PAGES_PER_WQE);
@@ -702,7 +710,7 @@ struct mlx5e_rq {
                struct {
                        struct mlx5_wq_cyc          wq;
                        struct mlx5e_wqe_frag_info *frags;
-                       union mlx5e_alloc_unit     *alloc_units;
+                       union mlx5e_alloc_units    *alloc_units;
                        struct mlx5e_rq_frags_info  info;
                        mlx5e_fp_skb_from_cqe       skb_from_cqe;
                } wqe;

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.c
index fab7876..8a5ae80 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.c
@@ -163,13 +163,10 @@ int mlx5e_xsk_alloc_rx_wqes_batched(struct mlx5e_rq *rq, u16 ix, int wqe_bulk)
        u32 contig, alloc;
        int i;
 
-       /* mlx5e_init_frags_partition creates a 1:1 mapping between
-        * rq->wqe.frags and rq->wqe.alloc_units, which allows us to
-        * allocate XDP buffers straight into alloc_units.
+       /* Each rq->wqe.frags->xskp is 1:1 mapped to an element inside the
+        * rq->wqe.alloc_units->xsk_buffs array allocated here.
         */
-       BUILD_BUG_ON(sizeof(rq->wqe.alloc_units[0]) !=
-                    sizeof(rq->wqe.alloc_units[0].xsk));
-       buffs = (struct xdp_buff **)rq->wqe.alloc_units;
+       buffs = rq->wqe.alloc_units->xsk_buffs;
        contig = mlx5_wq_cyc_get_size(wq) - ix;
        if (wqe_bulk <= contig) {
                alloc = xsk_buff_alloc_batch(rq->xsk_pool, buffs + ix, wqe_bulk);
@@ -189,7 +186,7 @@ int mlx5e_xsk_alloc_rx_wqes_batched(struct mlx5e_rq *rq, u16 ix, int wqe_bulk)
                /* Assumes log_num_frags == 0. */
                frag = &rq->wqe.frags[j];
 
-               addr = xsk_buff_xdp_get_frame_dma(frag->au->xsk);
+               addr = xsk_buff_xdp_get_frame_dma(*frag->xskp);
                wqe->data[0].addr = cpu_to_be64(addr + rq->buff.headroom);
        }
 
@@ -211,11 +208,11 @@ int mlx5e_xsk_alloc_rx_wqes(struct mlx5e_rq *rq, u16 ix, int wqe_bulk)
                /* Assumes log_num_frags == 0. */
                frag = &rq->wqe.frags[j];
 
-               frag->au->xsk = xsk_buff_alloc(rq->xsk_pool);
-               if (unlikely(!frag->au->xsk))
+               *frag->xskp = xsk_buff_alloc(rq->xsk_pool);
+               if (unlikely(!*frag->xskp))
                        return i;
 
-               addr = xsk_buff_xdp_get_frame_dma(frag->au->xsk);
+               addr = xsk_buff_xdp_get_frame_dma(*frag->xskp);
                wqe->data[0].addr = cpu_to_be64(addr + rq->buff.headroom);
        }
 
@@ -306,7 +303,7 @@ struct sk_buff *mlx5e_xsk_skb_from_cqe_linear(struct mlx5e_rq *rq,
                                              struct mlx5_cqe64 *cqe,
                                              u32 cqe_bcnt)
 {
-       struct mlx5e_xdp_buff *mxbuf = xsk_buff_to_mxbuf(wi->au->xsk);
+       struct mlx5e_xdp_buff *mxbuf = xsk_buff_to_mxbuf(*wi->xskp);
        struct bpf_prog *prog;
 
        /* wi->offset is not used in this function, because xdp->data and the

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 90eac1a..917b98d 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -499,15 +499,9 @@ static void mlx5e_init_frags_partition(struct mlx5e_rq *rq)
        struct mlx5e_wqe_frag_info *prev = NULL;
        int i;
 
-       if (rq->xsk_pool) {
-               /* Assumptions used by XSK batched allocator. */
-               WARN_ON(rq->wqe.info.num_frags != 1);
-               WARN_ON(rq->wqe.info.log_num_frags != 0);
-               WARN_ON(rq->wqe.info.arr[0].frag_stride != PAGE_SIZE);
-       }
-
-       next_frag.au = &rq->wqe.alloc_units[0];
+       WARN_ON(rq->xsk_pool);
 
+       next_frag.pagep = &rq->wqe.alloc_units->pages[0];
        for (i = 0; i < mlx5_wq_cyc_get_size(&rq->wqe.wq); i++) {
                struct mlx5e_rq_frag_info *frag_info = &rq->wqe.info.arr[0];
                struct mlx5e_wqe_frag_info *frag =
@@ -516,7 +510,8 @@ static void mlx5e_init_frags_partition(struct mlx5e_rq *rq)
 
                for (f = 0; f < rq->wqe.info.num_frags; f++, frag++) {
                        if (next_frag.offset + frag_info[f].frag_stride > PAGE_SIZE) {
-                               next_frag.au++;
+                               /* Pages are assigned at runtime. */
+                               next_frag.pagep++;
                                next_frag.offset = 0;
                                if (prev)
                                        prev->last_in_page = true;
@@ -533,22 +528,59 @@ static void mlx5e_init_frags_partition(struct mlx5e_rq *rq)
                prev->last_in_page = true;
 }
 
-static int mlx5e_init_au_list(struct mlx5e_rq *rq, int wq_sz, int node)
+static void mlx5e_init_xsk_buffs(struct mlx5e_rq *rq)
+{
+       int i;
+
+       /* Assumptions used by XSK batched allocator. */
+       WARN_ON(rq->wqe.info.num_frags != 1);
+       WARN_ON(rq->wqe.info.log_num_frags != 0);
+       WARN_ON(rq->wqe.info.arr[0].frag_stride != PAGE_SIZE);
+
+       /* Considering the above assumptions a fragment maps to a single
+        * xsk_buff.
+        */
+       for (i = 0; i < mlx5_wq_cyc_get_size(&rq->wqe.wq); i++)
+               rq->wqe.frags[i].xskp = &rq->wqe.alloc_units->xsk_buffs[i];
+}
+
+static int mlx5e_init_wqe_alloc_info(struct mlx5e_rq *rq, int node)
 {
+       int wq_sz = mlx5_wq_cyc_get_size(&rq->wqe.wq);
        int len = wq_sz << rq->wqe.info.log_num_frags;
+       struct mlx5e_wqe_frag_info *frags;
+       union mlx5e_alloc_units *aus;
+       int aus_sz;
+
+       if (rq->xsk_pool)
+               aus_sz = sizeof(*aus->xsk_buffs);
+       else
+               aus_sz = sizeof(*aus->pages);
+
+       aus = kvzalloc_node(array_size(len, aus_sz), GFP_KERNEL, node);
+       if (!aus)
+               return -ENOMEM;
 
-       rq->wqe.alloc_units = kvzalloc_node(array_size(len, sizeof(*rq->wqe.alloc_units)),
-                                           GFP_KERNEL, node);
-       if (!rq->wqe.alloc_units)
+       frags = kvzalloc_node(array_size(len, sizeof(*frags)), GFP_KERNEL, node);
+       if (!frags) {
+               kvfree(aus);
                return -ENOMEM;
+       }
+
+       rq->wqe.alloc_units = aus;
+       rq->wqe.frags = frags;
 
-       mlx5e_init_frags_partition(rq);
+       if (rq->xsk_pool)
+               mlx5e_init_xsk_buffs(rq);
+       else
+               mlx5e_init_frags_partition(rq);
 
        return 0;
 }
 
-static void mlx5e_free_au_list(struct mlx5e_rq *rq)
+static void mlx5e_free_wqe_alloc_info(struct mlx5e_rq *rq)
 {
+       kvfree(rq->wqe.frags);
        kvfree(rq->wqe.alloc_units);
 }
 
@@ -778,18 +810,9 @@ static int mlx5e_alloc_rq(struct mlx5e_params *params,
                rq->wqe.info = rqp->frags_info;
                rq->buff.frame0_sz = rq->wqe.info.arr[0].frag_stride;
 
-               rq->wqe.frags =
-                       kvzalloc_node(array_size(sizeof(*rq->wqe.frags),
-                                       (wq_sz << rq->wqe.info.log_num_frags)),
-                                     GFP_KERNEL, node);
-               if (!rq->wqe.frags) {
-                       err = -ENOMEM;
-                       goto err_rq_wq_destroy;
-               }
-
-               err = mlx5e_init_au_list(rq, wq_sz, node);
+               err = mlx5e_init_wqe_alloc_info(rq, node);
                if (err)
-                       goto err_rq_frags;
+                       goto err_rq_wq_destroy;
        }
 
        if (xsk) {
@@ -888,9 +911,7 @@ err_rq_drop_page:
                mlx5e_free_mpwqe_rq_drop_page(rq);
                break;
        default: /* MLX5_WQ_TYPE_CYCLIC */
-               mlx5e_free_au_list(rq);
-err_rq_frags:
-               kvfree(rq->wqe.frags);
+               mlx5e_free_wqe_alloc_info(rq);
        }
 err_rq_wq_destroy:
        mlx5_wq_destroy(&rq->wq_ctrl);
@@ -921,8 +942,7 @@ static void mlx5e_free_rq(struct mlx5e_rq *rq)
                mlx5e_rq_free_shampo(rq);
                break;
        default: /* MLX5_WQ_TYPE_CYCLIC */
-               kvfree(rq->wqe.frags);
-               mlx5e_free_au_list(rq);
+               mlx5e_free_wqe_alloc_info(rq);
        }
 
        for (i = rq->page_cache.head; i != rq->page_cache.tail;

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 3630011..74e7e00 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -371,12 +371,12 @@ static inline int mlx5e_get_rx_frag(struct mlx5e_rq *rq,
        int err = 0;
 
        if (!frag->offset)
-               /* On first frag (offset == 0), replenish page (alloc_unit actually).
-                * Other frags that point to the same alloc_unit (with a different
+               /* On first frag (offset == 0), replenish page.
+                * Other frags that point to the same page (with a different
                 * offset) should just use the new one without replenishing again
                 * by themselves.
                 */
-               err = mlx5e_page_alloc_pool(rq, &frag->au->page);
+               err = mlx5e_page_alloc_pool(rq, frag->pagep);
 
        return err;
 }
@@ -386,7 +386,7 @@ static inline void mlx5e_put_rx_frag(struct mlx5e_rq *rq,
                                     bool recycle)
 {
        if (frag->last_in_page)
-               mlx5e_page_release_dynamic(rq, frag->au->page, recycle);
+               mlx5e_page_release_dynamic(rq, *frag->pagep, recycle);
 }
 
 static inline struct mlx5e_wqe_frag_info *get_frag(struct mlx5e_rq *rq, u16 ix)
@@ -410,7 +410,7 @@ static int mlx5e_alloc_rx_wqe(struct mlx5e_rq *rq, struct mlx5e_rx_wqe_cyc *wqe,
                        goto free_frags;
 
                headroom = i == 0 ? rq->buff.headroom : 0;
-               addr = page_pool_get_dma_addr(frag->au->page);
+               addr = page_pool_get_dma_addr(*frag->pagep);
                wqe->data[i].addr = cpu_to_be64(addr + frag->offset + headroom);
        }
 
@@ -434,7 +434,7 @@ static inline void mlx5e_free_rx_wqe(struct mlx5e_rq *rq,
                 * put into the Reuse Ring, because there is no way to return
                 * the page to the userspace when the interface goes down.
                 */
-               xsk_buff_free(wi->au->xsk);
+               xsk_buff_free(*wi->xskp);
                return;
        }
 
@@ -1587,8 +1587,8 @@ static struct sk_buff *
 mlx5e_skb_from_cqe_linear(struct mlx5e_rq *rq, struct mlx5e_wqe_frag_info *wi,
                          struct mlx5_cqe64 *cqe, u32 cqe_bcnt)
 {
-       union mlx5e_alloc_unit *au = wi->au;
        u16 rx_headroom = rq->buff.headroom;
+       struct page *page = *wi->pagep;
        struct bpf_prog *prog;
        struct sk_buff *skb;
        u32 metasize = 0;
@@ -1596,11 +1596,11 @@ mlx5e_skb_from_cqe_linear(struct mlx5e_rq *rq, struct mlx5e_wqe_frag_info *wi,
        dma_addr_t addr;
        u32 frag_size;
 
-       va             = page_address(au->page) + wi->offset;
+       va             = page_address(page) + wi->offset;
        data           = va + rx_headroom;
        frag_size      = MLX5_SKB_FRAG_SZ(rx_headroom + cqe_bcnt);
 
-       addr = page_pool_get_dma_addr(au->page);
+       addr = page_pool_get_dma_addr(page);
        dma_sync_single_range_for_cpu(rq->pdev, addr, wi->offset,
                                      frag_size, rq->buff.map_dir);
        net_prefetch(data);
@@ -1624,7 +1624,7 @@ mlx5e_skb_from_cqe_linear(struct mlx5e_rq *rq, struct mlx5e_wqe_frag_info *wi,
                return NULL;
 
        /* queue up for recycling/reuse */
-       page_ref_inc(au->page);
+       page_ref_inc(page);
 
        return skb;
 }
@@ -1635,8 +1635,8 @@ mlx5e_skb_from_cqe_nonlinear(struct mlx5e_rq *rq, struct mlx5e_wqe_frag_info *wi
 {
        struct mlx5e_rq_frag_info *frag_info = &rq->wqe.info.arr[0];
        struct mlx5e_wqe_frag_info *head_wi = wi;
-       union mlx5e_alloc_unit *au = wi->au;
        u16 rx_headroom = rq->buff.headroom;
+       struct page *page = *wi->pagep;
        struct skb_shared_info *sinfo;
        struct mlx5e_xdp_buff mxbuf;
        u32 frag_consumed_bytes;
@@ -1646,10 +1646,10 @@ mlx5e_skb_from_cqe_nonlinear(struct mlx5e_rq *rq, struct mlx5e_wqe_frag_info *wi
        u32 truesize;
        void *va;
 
-       va = page_address(au->page) + wi->offset;
+       va = page_address(page) + wi->offset;
        frag_consumed_bytes = min_t(u32, frag_info->frag_size, cqe_bcnt);
 
-       addr = page_pool_get_dma_addr(au->page);
+       addr = page_pool_get_dma_addr(page);
        dma_sync_single_range_for_cpu(rq->pdev, addr, wi->offset,
                                      rq->buff.frame0_sz, rq->buff.map_dir);
        net_prefetchw(va); /* xdp_frame data area */
@@ -1666,11 +1666,11 @@ mlx5e_skb_from_cqe_nonlinear(struct mlx5e_rq *rq, struct mlx5e_wqe_frag_info *wi
        while (cqe_bcnt) {
                skb_frag_t *frag;
 
-               au = wi->au;
+               page = *wi->pagep;
 
                frag_consumed_bytes = min_t(u32, frag_info->frag_size, cqe_bcnt);
 
-               addr = page_pool_get_dma_addr(au->page);
+               addr = page_pool_get_dma_addr(page);
                dma_sync_single_for_cpu(rq->pdev, addr + wi->offset,
                                        frag_consumed_bytes, rq->buff.map_dir);
 
@@ -1684,11 +1684,11 @@ mlx5e_skb_from_cqe_nonlinear(struct mlx5e_rq *rq, struct mlx5e_wqe_frag_info *wi
                }
 
                frag = &sinfo->frags[sinfo->nr_frags++];
-               __skb_frag_set_page(frag, au->page);
+               __skb_frag_set_page(frag, page);
                skb_frag_off_set(frag, wi->offset);
                skb_frag_size_set(frag, frag_consumed_bytes);
 
-               if (page_is_pfmemalloc(au->page))
+               if (page_is_pfmemalloc(page))
                        xdp_buff_set_frag_pfmemalloc(&mxbuf.xdp);
 
                sinfo->xdp_frags_size += frag_consumed_bytes;
@@ -1717,7 +1717,7 @@ mlx5e_skb_from_cqe_nonlinear(struct mlx5e_rq *rq, struct mlx5e_wqe_frag_info *wi
        if (unlikely(!skb))
                return NULL;
 
-       page_ref_inc(head_wi->au->page);
+       page_ref_inc(*head_wi->pagep);
 
        if (xdp_buff_has_frags(&mxbuf.xdp)) {
                int i;