Implement the new driver method 'reg_user_mr_dmabuf'. Utilize the core functions to import dma-buf based memory region and update the mappings.
Add code to handle dma-buf related page fault.
Signed-off-by: Jianxin Xiong jianxin.xiong@intel.com Reviewed-by: Sean Hefty sean.hefty@intel.com Acked-by: Michael J. Ruhl michael.j.ruhl@intel.com Acked-by: Christian Koenig christian.koenig@amd.com Acked-by: Daniel Vetter daniel.vetter@ffwll.ch --- drivers/infiniband/hw/mlx5/main.c | 2 + drivers/infiniband/hw/mlx5/mlx5_ib.h | 18 ++++ drivers/infiniband/hw/mlx5/mr.c | 128 +++++++++++++++++++++++++-- drivers/infiniband/hw/mlx5/odp.c | 86 +++++++++++++++++- 4 files changed, 225 insertions(+), 9 deletions(-)
diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c index 36b15a063e68..e647ea4bf9ce 100644 --- a/drivers/infiniband/hw/mlx5/main.c +++ b/drivers/infiniband/hw/mlx5/main.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB /* * Copyright (c) 2013-2020, Mellanox Technologies inc. All rights reserved. + * Copyright (c) 2020, Intel Corporation. All rights reserved. */
#include <linux/debugfs.h> @@ -4055,6 +4056,7 @@ static const struct ib_device_ops mlx5_ib_dev_ops = { .query_srq = mlx5_ib_query_srq, .query_ucontext = mlx5_ib_query_ucontext, .reg_user_mr = mlx5_ib_reg_user_mr, + .reg_user_mr_dmabuf = mlx5_ib_reg_user_mr_dmabuf, .req_notify_cq = mlx5_ib_arm_cq, .rereg_user_mr = mlx5_ib_rereg_user_mr, .resize_cq = mlx5_ib_resize_cq, diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h index bb44080170be..3ef6872fa258 100644 --- a/drivers/infiniband/hw/mlx5/mlx5_ib.h +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h @@ -1,6 +1,7 @@ /* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */ /* * Copyright (c) 2013-2020, Mellanox Technologies inc. All rights reserved. + * Copyright (c) 2020, Intel Corporation. All rights reserved. */
#ifndef MLX5_IB_H @@ -665,6 +666,12 @@ static inline bool is_odp_mr(struct mlx5_ib_mr *mr) mr->umem->is_odp; }
+static inline bool is_dmabuf_mr(struct mlx5_ib_mr *mr) +{ + return IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING) && mr->umem && + mr->umem->is_dmabuf; +} + struct mlx5_ib_mw { struct ib_mw ibmw; struct mlx5_core_mkey mmkey; @@ -1200,6 +1207,10 @@ 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); +struct ib_mr *mlx5_ib_reg_user_mr_dmabuf(struct ib_pd *pd, u64 start, + u64 length, u64 virt_addr, + int fd, int access_flags, + struct ib_udata *udata); int mlx5_ib_advise_mr(struct ib_pd *pd, enum ib_uverbs_advise_mr_advice advice, u32 flags, @@ -1210,11 +1221,13 @@ int mlx5_ib_alloc_mw(struct ib_mw *mw, struct ib_udata *udata); int mlx5_ib_dealloc_mw(struct ib_mw *mw); int mlx5_ib_update_xlt(struct mlx5_ib_mr *mr, u64 idx, int npages, int page_shift, int flags); +int mlx5_ib_update_mr_pas(struct mlx5_ib_mr *mr, unsigned int flags); struct mlx5_ib_mr *mlx5_ib_alloc_implicit_mr(struct mlx5_ib_pd *pd, struct ib_udata *udata, int access_flags); void mlx5_ib_free_implicit_mr(struct mlx5_ib_mr *mr); void mlx5_ib_fence_odp_mr(struct mlx5_ib_mr *mr); +void mlx5_ib_fence_dmabuf_mr(struct mlx5_ib_mr *mr); int mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start, u64 length, u64 virt_addr, int access_flags, struct ib_pd *pd, struct ib_udata *udata); @@ -1306,6 +1319,7 @@ int mlx5_ib_advise_mr_prefetch(struct ib_pd *pd, enum ib_uverbs_advise_mr_advice advice, u32 flags, struct ib_sge *sg_list, u32 num_sge); int mlx5_ib_init_odp_mr(struct mlx5_ib_mr *mr, bool enable); +int mlx5_ib_init_dmabuf_mr(struct mlx5_ib_mr *mr); #else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */ static inline void mlx5_ib_internal_fill_odp_caps(struct mlx5_ib_dev *dev) { @@ -1331,6 +1345,10 @@ static inline int mlx5_ib_init_odp_mr(struct mlx5_ib_mr *mr, bool enable) { return -EOPNOTSUPP; } +static inline int mlx5_ib_init_dmabuf_mr(struct mlx5_ib_mr *mr) +{ + return -EOPNOTSUPP; +} #endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
extern const struct mmu_interval_notifier_ops mlx5_mn_ops; diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c index 9f653b4a5438..4551d41596f9 100644 --- a/drivers/infiniband/hw/mlx5/mr.c +++ b/drivers/infiniband/hw/mlx5/mr.c @@ -1,5 +1,6 @@ /* * Copyright (c) 2013-2015, Mellanox Technologies. All rights reserved. + * Copyright (c) 2020, Intel Corporation. All rights reserved. * * This software is available to you under a choice of one of two * licenses. You may choose to be licensed under the terms of the GNU @@ -36,6 +37,8 @@ #include <linux/debugfs.h> #include <linux/export.h> #include <linux/delay.h> +#include <linux/dma-buf.h> +#include <linux/dma-resv.h> #include <rdma/ib_umem.h> #include <rdma/ib_umem_odp.h> #include <rdma/ib_verbs.h> @@ -957,6 +960,16 @@ static struct mlx5_cache_ent *mr_cache_ent_from_order(struct mlx5_ib_dev *dev, return &cache->ent[order]; }
+static unsigned int mlx5_umem_dmabuf_default_pgsz(struct ib_umem *umem, + u64 iova) +{ + if ((iova ^ umem->address) & (PAGE_SIZE - 1)) + return 0; + + umem->iova = iova; + return PAGE_SIZE; +} + static struct mlx5_ib_mr *alloc_mr_from_cache(struct ib_pd *pd, struct ib_umem *umem, u64 iova, int access_flags) @@ -966,7 +979,11 @@ static struct mlx5_ib_mr *alloc_mr_from_cache(struct ib_pd *pd, struct mlx5_ib_mr *mr; unsigned int page_size;
- page_size = mlx5_umem_find_best_pgsz(umem, mkc, log_page_size, 0, iova); + if (umem->is_dmabuf) + page_size = mlx5_umem_dmabuf_default_pgsz(umem, iova); + else + page_size = mlx5_umem_find_best_pgsz(umem, mkc, log_page_size, + 0, iova); if (WARN_ON(!page_size)) return ERR_PTR(-EINVAL); ent = mr_cache_ent_from_order( @@ -1212,8 +1229,10 @@ int mlx5_ib_update_xlt(struct mlx5_ib_mr *mr, u64 idx, int npages,
/* * Send the DMA list to the HW for a normal MR using UMR. + * Dmabuf MR is handled in a similar way, except that the MLX5_IB_UPD_XLT_ZAP + * flag may be used. */ -static int mlx5_ib_update_mr_pas(struct mlx5_ib_mr *mr, unsigned int flags) +int mlx5_ib_update_mr_pas(struct mlx5_ib_mr *mr, unsigned int flags) { struct mlx5_ib_dev *dev = mr->dev; struct device *ddev = dev->ib_dev.dev.parent; @@ -1255,6 +1274,10 @@ static int mlx5_ib_update_mr_pas(struct mlx5_ib_mr *mr, unsigned int flags) cur_mtt->ptag = cpu_to_be64(rdma_block_iter_dma_address(&biter) | MLX5_IB_MTT_PRESENT); + + if (mr->umem->is_dmabuf && (flags & MLX5_IB_UPD_XLT_ZAP)) + cur_mtt->ptag = 0; + cur_mtt++; }
@@ -1291,8 +1314,11 @@ static struct mlx5_ib_mr *reg_create(struct ib_mr *ibmr, struct ib_pd *pd, int err; bool pg_cap = !!(MLX5_CAP_GEN(dev->mdev, pg));
- page_size = - mlx5_umem_find_best_pgsz(umem, mkc, log_page_size, 0, iova); + if (umem->is_dmabuf) + page_size = mlx5_umem_dmabuf_default_pgsz(umem, iova); + else + page_size = mlx5_umem_find_best_pgsz(umem, mkc, log_page_size, + 0, iova); if (WARN_ON(!page_size)) return ERR_PTR(-EINVAL);
@@ -1581,6 +1607,96 @@ struct ib_mr *mlx5_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length, return ERR_PTR(err); }
+static void mlx5_ib_dmabuf_invalidate_cb(struct dma_buf_attachment *attach) +{ + struct ib_umem_dmabuf *umem_dmabuf = attach->importer_priv; + struct mlx5_ib_mr *mr = umem_dmabuf->private; + + dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv); + + if (!umem_dmabuf->sgt) + return; + + mlx5_ib_update_mr_pas(mr, MLX5_IB_UPD_XLT_ZAP); + ib_umem_dmabuf_unmap_pages(umem_dmabuf); +} + +static struct dma_buf_attach_ops mlx5_ib_dmabuf_attach_ops = { + .allow_peer2peer = 1, + .move_notify = mlx5_ib_dmabuf_invalidate_cb, +}; + +struct ib_mr *mlx5_ib_reg_user_mr_dmabuf(struct ib_pd *pd, u64 offset, + u64 length, u64 virt_addr, + int fd, int access_flags, + struct ib_udata *udata) +{ + struct mlx5_ib_dev *dev = to_mdev(pd->device); + struct mlx5_ib_mr *mr = NULL; + struct ib_umem *umem; + int err; + + if (!IS_ENABLED(CONFIG_INFINIBAND_USER_MEM)) + return ERR_PTR(-EOPNOTSUPP); + + mlx5_ib_dbg(dev, + "offset 0x%llx, virt_addr 0x%llx, length 0x%llx, fd %d, access_flags 0x%x\n", + offset, virt_addr, length, fd, access_flags); + + if (!mlx5_ib_can_load_pas_with_umr(dev, length)) + return ERR_PTR(-EINVAL); + + umem = ib_umem_dmabuf_get(&dev->ib_dev, offset, length, fd, access_flags, + &mlx5_ib_dmabuf_attach_ops); + if (IS_ERR(umem)) { + mlx5_ib_dbg(dev, "umem get failed (%ld)\n", PTR_ERR(umem)); + return ERR_PTR(PTR_ERR(umem)); + } + + mr = alloc_mr_from_cache(pd, umem, virt_addr, access_flags); + if (IS_ERR(mr)) + mr = NULL; + + if (!mr) { + mutex_lock(&dev->slow_path_mutex); + mr = reg_create(NULL, pd, umem, virt_addr, access_flags, + false); + mutex_unlock(&dev->slow_path_mutex); + } + + if (IS_ERR(mr)) { + err = PTR_ERR(mr); + goto error; + } + + mlx5_ib_dbg(dev, "mkey 0x%x\n", mr->mmkey.key); + + mr->umem = umem; + atomic_add(ib_umem_num_pages(mr->umem), &dev->mdev->priv.reg_pages); + set_mr_fields(dev, mr, length, access_flags); + + to_ib_umem_dmabuf(umem)->private = mr; + init_waitqueue_head(&mr->q_deferred_work); + atomic_set(&mr->num_deferred_work, 0); + err = xa_err(xa_store(&dev->odp_mkeys, + mlx5_base_mkey(mr->mmkey.key), &mr->mmkey, + GFP_KERNEL)); + if (err) { + dereg_mr(dev, mr); + return ERR_PTR(err); + } + + err = mlx5_ib_init_dmabuf_mr(mr); + if (err) { + dereg_mr(dev, mr); + return ERR_PTR(err); + } + return &mr->ibmr; +error: + ib_umem_release(umem); + return ERR_PTR(err); +} + /** * mlx5_mr_cache_invalidate - Fence all DMA on the MR * @mr: The MR to fence @@ -1649,7 +1765,7 @@ int mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start, if (!mr->umem) return -EINVAL;
- if (is_odp_mr(mr)) + if (is_odp_mr(mr) || is_dmabuf_mr(mr)) return -EOPNOTSUPP;
if (flags & IB_MR_REREG_TRANS) { @@ -1812,6 +1928,8 @@ static void dereg_mr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr) /* Stop all DMA */ if (is_odp) mlx5_ib_fence_odp_mr(mr); + else if (is_dmabuf_mr(mr)) + mlx5_ib_fence_dmabuf_mr(mr); else clean_mr(dev, mr);
diff --git a/drivers/infiniband/hw/mlx5/odp.c b/drivers/infiniband/hw/mlx5/odp.c index 5c853ec1b0d8..41aeb9200427 100644 --- a/drivers/infiniband/hw/mlx5/odp.c +++ b/drivers/infiniband/hw/mlx5/odp.c @@ -33,6 +33,8 @@ #include <rdma/ib_umem.h> #include <rdma/ib_umem_odp.h> #include <linux/kernel.h> +#include <linux/dma-buf.h> +#include <linux/dma-resv.h>
#include "mlx5_ib.h" #include "cmd.h" @@ -664,6 +666,37 @@ void mlx5_ib_fence_odp_mr(struct mlx5_ib_mr *mr) dma_fence_odp_mr(mr); }
+/** + * mlx5_ib_fence_dmabuf_mr - Stop all access to the dmabuf MR + * @mr: to fence + * + * On return no parallel threads will be touching this MR and no DMA will be + * active. + */ +void mlx5_ib_fence_dmabuf_mr(struct mlx5_ib_mr *mr) +{ + struct ib_umem_dmabuf *umem_dmabuf = to_ib_umem_dmabuf(mr->umem); + + /* Prevent new page faults and prefetch requests from succeeding */ + xa_erase(&mr->dev->odp_mkeys, mlx5_base_mkey(mr->mmkey.key)); + + /* Wait for all running page-fault handlers to finish. */ + synchronize_srcu(&mr->dev->odp_srcu); + + wait_event(mr->q_deferred_work, !atomic_read(&mr->num_deferred_work)); + + dma_resv_lock(umem_dmabuf->attach->dmabuf->resv, NULL); + mlx5_mr_cache_invalidate(mr); + umem_dmabuf->private = NULL; + ib_umem_dmabuf_unmap_pages(umem_dmabuf); + dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv); + + if (!mr->cache_ent) { + mlx5_core_destroy_mkey(mr->dev->mdev, &mr->mmkey); + WARN_ON(mr->descs); + } +} + #define MLX5_PF_FLAGS_DOWNGRADE BIT(1) #define MLX5_PF_FLAGS_SNAPSHOT BIT(2) #define MLX5_PF_FLAGS_ENABLE BIT(3) @@ -797,6 +830,41 @@ static int pagefault_implicit_mr(struct mlx5_ib_mr *imr, return ret; }
+static int pagefault_dmabuf_mr(struct mlx5_ib_mr *mr, size_t bcnt, + u32 *bytes_mapped, u32 flags) +{ + struct ib_umem_dmabuf *umem_dmabuf = to_ib_umem_dmabuf(mr->umem); + u32 xlt_flags = 0; + int err; + unsigned int page_size; + + if (flags & MLX5_PF_FLAGS_ENABLE) + xlt_flags |= MLX5_IB_UPD_XLT_ENABLE; + + dma_resv_lock(umem_dmabuf->attach->dmabuf->resv, NULL); + err = ib_umem_dmabuf_map_pages(umem_dmabuf); + if (!err) { + page_size = mlx5_umem_find_best_pgsz(&umem_dmabuf->umem, mkc, + log_page_size, 0, + umem_dmabuf->umem.iova); + if (unlikely(page_size < PAGE_SIZE)) { + ib_umem_dmabuf_unmap_pages(umem_dmabuf); + err = -EINVAL; + } else { + err = mlx5_ib_update_mr_pas(mr, xlt_flags); + } + } + dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv); + + if (err) + return err; + + if (bytes_mapped) + *bytes_mapped += bcnt; + + return ib_umem_num_pages(mr->umem); +} + /* * Returns: * -EFAULT: The io_virt->bcnt is not within the MR, it covers pages that are @@ -815,6 +883,9 @@ static int pagefault_mr(struct mlx5_ib_mr *mr, u64 io_virt, size_t bcnt, if (unlikely(io_virt < mr->mmkey.iova)) return -EFAULT;
+ if (is_dmabuf_mr(mr)) + return pagefault_dmabuf_mr(mr, bcnt, bytes_mapped, flags); + if (!odp->is_implicit_odp) { u64 user_va;
@@ -845,6 +916,16 @@ int mlx5_ib_init_odp_mr(struct mlx5_ib_mr *mr, bool enable) return ret >= 0 ? 0 : ret; }
+int mlx5_ib_init_dmabuf_mr(struct mlx5_ib_mr *mr) +{ + int ret; + + ret = pagefault_dmabuf_mr(mr, mr->umem->length, NULL, + MLX5_PF_FLAGS_ENABLE); + + return ret >= 0 ? 0 : ret; +} + struct pf_frame { struct pf_frame *next; u32 key; @@ -1747,7 +1828,6 @@ get_prefetchable_mr(struct ib_pd *pd, enum ib_uverbs_advise_mr_advice advice, { struct mlx5_ib_dev *dev = to_mdev(pd->device); struct mlx5_core_mkey *mmkey; - struct ib_umem_odp *odp; struct mlx5_ib_mr *mr;
lockdep_assert_held(&dev->odp_srcu); @@ -1761,11 +1841,9 @@ get_prefetchable_mr(struct ib_pd *pd, enum ib_uverbs_advise_mr_advice advice, if (mr->ibmr.pd != pd) return NULL;
- odp = to_ib_umem_odp(mr->umem); - /* prefetch with write-access must be supported by the MR */ if (advice == IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH_WRITE && - !odp->umem.writable) + !mr->umem->writable) return NULL;
return mr;