From 832a6b06ab5e13c228fc27e333ad360aa03ace6f Mon Sep 17 00:00:00 2001 From: Haggai Eran Date: Thu, 11 Dec 2014 17:04:22 +0200 Subject: [PATCH] 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/mem.c | 19 +++- drivers/infiniband/hw/mlx5/mlx5_ib.h | 5 + drivers/infiniband/hw/mlx5/mr.c | 132 ++++++++++++++++++++++++++- include/linux/mlx5/device.h | 1 + 4 files changed, 149 insertions(+), 8 deletions(-) diff --git a/drivers/infiniband/hw/mlx5/mem.c b/drivers/infiniband/hw/mlx5/mem.c index 5f7b30147180..b56e4c5593ee 100644 --- a/drivers/infiniband/hw/mlx5/mem.c +++ b/drivers/infiniband/hw/mlx5/mem.c @@ -140,12 +140,16 @@ static u64 umem_dma_to_mtt(dma_addr_t umem_dma) * dev - mlx5_ib device * umem - umem to use to fill the pages * page_shift - determines the page size used in the resulting array + * offset - offset into the umem to start from, + * only implemented for ODP umems + * num_pages - total number of pages to fill * pas - bus addresses array to fill * access_flags - access flags to set on all present pages. use enum mlx5_ib_mtt_access_flags for this. */ -void mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem, - int page_shift, __be64 *pas, int access_flags) +void __mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem, + int page_shift, size_t offset, size_t num_pages, + __be64 *pas, int access_flags) { unsigned long umem_page_shift = ilog2(umem->page_size); int shift = page_shift - umem_page_shift; @@ -160,13 +164,11 @@ void mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem, const bool odp = umem->odp_data != NULL; if (odp) { - int num_pages = ib_umem_num_pages(umem); - WARN_ON(shift != 0); WARN_ON(access_flags != (MLX5_IB_MTT_READ | MLX5_IB_MTT_WRITE)); for (i = 0; i < num_pages; ++i) { - dma_addr_t pa = umem->odp_data->dma_list[i]; + dma_addr_t pa = umem->odp_data->dma_list[offset + i]; pas[i] = cpu_to_be64(umem_dma_to_mtt(pa)); } @@ -194,6 +196,13 @@ void mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem, } } +void mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem, + int page_shift, __be64 *pas, int access_flags) +{ + return __mlx5_ib_populate_pas(dev, umem, page_shift, 0, + ib_umem_num_pages(umem), pas, + access_flags); +} int mlx5_ib_get_buf_offset(u64 addr, int page_shift, u32 *offset) { u64 page_size; diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h index 83c1690e9dd0..6856e27bfb6a 100644 --- a/drivers/infiniband/hw/mlx5/mlx5_ib.h +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h @@ -527,6 +527,8 @@ struct ib_mr *mlx5_ib_get_dma_mr(struct ib_pd *pd, int acc); struct ib_mr *mlx5_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length, u64 virt_addr, int access_flags, struct ib_udata *udata); +int mlx5_ib_update_mtt(struct mlx5_ib_mr *mr, u64 start_page_index, + int npages, int zap); int mlx5_ib_dereg_mr(struct ib_mr *ibmr); int mlx5_ib_destroy_mr(struct ib_mr *ibmr); struct ib_mr *mlx5_ib_create_mr(struct ib_pd *pd, @@ -558,6 +560,9 @@ int mlx5_ib_init_fmr(struct mlx5_ib_dev *dev); void mlx5_ib_cleanup_fmr(struct mlx5_ib_dev *dev); void mlx5_ib_cont_pages(struct ib_umem *umem, u64 addr, int *count, int *shift, int *ncont, int *order); +void __mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem, + int page_shift, size_t offset, size_t num_pages, + __be64 *pas, int access_flags); void mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem, int page_shift, __be64 *pas, int access_flags); void mlx5_ib_copy_pas(u64 *old, u64 *new, int step, int num); diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c index 49fc3ca735a4..38b06267798e 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 @@ static struct mlx5_ib_mr *reg_umr(struct ib_pd *pd, struct ib_umem *umem, 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, diff --git a/include/linux/mlx5/device.h b/include/linux/mlx5/device.h index 64512a7354cb..4e5bd813bb9a 100644 --- a/include/linux/mlx5/device.h +++ b/include/linux/mlx5/device.h @@ -200,6 +200,7 @@ enum { #define MLX5_UMR_MTT_ALIGNMENT 0x40 #define MLX5_UMR_MTT_MASK (MLX5_UMR_MTT_ALIGNMENT - 1) +#define MLX5_UMR_MTT_MIN_CHUNK_SIZE MLX5_UMR_MTT_ALIGNMENT enum mlx5_event { MLX5_EVENT_TYPE_COMP = 0x0, -- GitLab