From 832a6b06ab5e13c228fc27e333ad360aa03ace6f Mon Sep 17 00:00:00 2001 From: Haggai Eran Date: Thu, 11 Dec 2014 17:04:22 +0200 Subject: IB/mlx5: Add mlx5_ib_update_mtt to update page tables after creation The new function allows updating the page tables of a memory region after it was created. This can be used to handle page faults and page invalidations. Since mlx5_ib_update_mtt will need to work from within page invalidation, so it must not block on memory allocation. It employs an atomic memory allocation mechanism that is used as a fallback when kmalloc(GFP_ATOMIC) fails. In order to reuse code from mlx5_ib_populate_pas, the patch splits this function and add the needed parameters. Signed-off-by: Haggai Eran Signed-off-by: Shachar Raindel Signed-off-by: Roland Dreier --- drivers/infiniband/hw/mlx5/mr.c | 132 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 129 insertions(+), 3 deletions(-) (limited to 'drivers/infiniband/hw/mlx5/mr.c') diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c index 49fc3ca..38b0626 100644 --- a/drivers/infiniband/hw/mlx5/mr.c +++ b/drivers/infiniband/hw/mlx5/mr.c @@ -44,9 +44,13 @@ enum { MAX_PENDING_REG_MR = 8, }; -enum { - MLX5_UMR_ALIGN = 2048 -}; +#define MLX5_UMR_ALIGN 2048 +#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING +static __be64 mlx5_ib_update_mtt_emergency_buffer[ + MLX5_UMR_MTT_MIN_CHUNK_SIZE/sizeof(__be64)] + __aligned(MLX5_UMR_ALIGN); +static DEFINE_MUTEX(mlx5_ib_update_mtt_emergency_buffer_mutex); +#endif static int order2idx(struct mlx5_ib_dev *dev, int order) { @@ -822,6 +826,128 @@ free_mr: return mr; } +#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING +int mlx5_ib_update_mtt(struct mlx5_ib_mr *mr, u64 start_page_index, int npages, + int zap) +{ + struct mlx5_ib_dev *dev = mr->dev; + struct device *ddev = dev->ib_dev.dma_device; + struct umr_common *umrc = &dev->umrc; + struct mlx5_ib_umr_context umr_context; + struct ib_umem *umem = mr->umem; + int size; + __be64 *pas; + dma_addr_t dma; + struct ib_send_wr wr, *bad; + struct mlx5_umr_wr *umrwr = (struct mlx5_umr_wr *)&wr.wr.fast_reg; + struct ib_sge sg; + int err = 0; + const int page_index_alignment = MLX5_UMR_MTT_ALIGNMENT / sizeof(u64); + const int page_index_mask = page_index_alignment - 1; + size_t pages_mapped = 0; + size_t pages_to_map = 0; + size_t pages_iter = 0; + int use_emergency_buf = 0; + + /* UMR copies MTTs in units of MLX5_UMR_MTT_ALIGNMENT bytes, + * so we need to align the offset and length accordingly */ + if (start_page_index & page_index_mask) { + npages += start_page_index & page_index_mask; + start_page_index &= ~page_index_mask; + } + + pages_to_map = ALIGN(npages, page_index_alignment); + + if (start_page_index + pages_to_map > MLX5_MAX_UMR_PAGES) + return -EINVAL; + + size = sizeof(u64) * pages_to_map; + size = min_t(int, PAGE_SIZE, size); + /* We allocate with GFP_ATOMIC to avoid recursion into page-reclaim + * code, when we are called from an invalidation. The pas buffer must + * be 2k-aligned for Connect-IB. */ + pas = (__be64 *)get_zeroed_page(GFP_ATOMIC); + if (!pas) { + mlx5_ib_warn(dev, "unable to allocate memory during MTT update, falling back to slower chunked mechanism.\n"); + pas = mlx5_ib_update_mtt_emergency_buffer; + size = MLX5_UMR_MTT_MIN_CHUNK_SIZE; + use_emergency_buf = 1; + mutex_lock(&mlx5_ib_update_mtt_emergency_buffer_mutex); + memset(pas, 0, size); + } + pages_iter = size / sizeof(u64); + dma = dma_map_single(ddev, pas, size, DMA_TO_DEVICE); + if (dma_mapping_error(ddev, dma)) { + mlx5_ib_err(dev, "unable to map DMA during MTT update.\n"); + err = -ENOMEM; + goto free_pas; + } + + for (pages_mapped = 0; + pages_mapped < pages_to_map && !err; + pages_mapped += pages_iter, start_page_index += pages_iter) { + dma_sync_single_for_cpu(ddev, dma, size, DMA_TO_DEVICE); + + npages = min_t(size_t, + pages_iter, + ib_umem_num_pages(umem) - start_page_index); + + if (!zap) { + __mlx5_ib_populate_pas(dev, umem, PAGE_SHIFT, + start_page_index, npages, pas, + MLX5_IB_MTT_PRESENT); + /* Clear padding after the pages brought from the + * umem. */ + memset(pas + npages, 0, size - npages * sizeof(u64)); + } + + dma_sync_single_for_device(ddev, dma, size, DMA_TO_DEVICE); + + memset(&wr, 0, sizeof(wr)); + wr.wr_id = (u64)(unsigned long)&umr_context; + + sg.addr = dma; + sg.length = ALIGN(npages * sizeof(u64), + MLX5_UMR_MTT_ALIGNMENT); + sg.lkey = dev->umrc.mr->lkey; + + wr.send_flags = MLX5_IB_SEND_UMR_FAIL_IF_FREE | + MLX5_IB_SEND_UMR_UPDATE_MTT; + wr.sg_list = &sg; + wr.num_sge = 1; + wr.opcode = MLX5_IB_WR_UMR; + umrwr->npages = sg.length / sizeof(u64); + umrwr->page_shift = PAGE_SHIFT; + umrwr->mkey = mr->mmr.key; + umrwr->target.offset = start_page_index; + + mlx5_ib_init_umr_context(&umr_context); + down(&umrc->sem); + err = ib_post_send(umrc->qp, &wr, &bad); + if (err) { + mlx5_ib_err(dev, "UMR post send failed, err %d\n", err); + } else { + wait_for_completion(&umr_context.done); + if (umr_context.status != IB_WC_SUCCESS) { + mlx5_ib_err(dev, "UMR completion failed, code %d\n", + umr_context.status); + err = -EFAULT; + } + } + up(&umrc->sem); + } + dma_unmap_single(ddev, dma, size, DMA_TO_DEVICE); + +free_pas: + if (!use_emergency_buf) + free_page((unsigned long)pas); + else + mutex_unlock(&mlx5_ib_update_mtt_emergency_buffer_mutex); + + return err; +} +#endif + static struct mlx5_ib_mr *reg_create(struct ib_pd *pd, u64 virt_addr, u64 length, struct ib_umem *umem, int npages, int page_shift, -- cgit v1.1