From: Jason Gunthorpe Date: Thu, 4 Mar 2021 12:07:44 +0000 (+0200) Subject: RDMA/mlx5: Consolidate MR destruction to mlx5_ib_dereg_mr() X-Git-Tag: microblaze-v5.14~80^2~131 X-Git-Url: http://git.monstr.eu/?p=linux-2.6-microblaze.git;a=commitdiff_plain;h=e6fb246ccafbdfc86e0750af021628132fdbceac RDMA/mlx5: Consolidate MR destruction to mlx5_ib_dereg_mr() Now that the SRCU stuff has been removed the entire MR destroy logic can be made a lot simpler. Currently there are many different ways to destroy a MR and it makes it really hard to do this task correctly. Route all destruction through mlx5_ib_dereg_mr() and make it work for all situations. Since it turns out all the different MR types do basically the same thing this removes a lot of knowledge of MR internals from ODP and leaves ODP just exporting an operation to clean up children. This fixes a few weird corner cases bugs and firmly uses the correct ordering of the MR destruction: - Stop parallel access to the mkey via the ODP xarray - Stop DMA - Release the umem - Clean up ODP children - Free/Recycle the MR Link: https://lore.kernel.org/r/20210304120745.1090751-4-leon@kernel.org Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe --- diff --git a/drivers/infiniband/core/umem_dmabuf.c b/drivers/infiniband/core/umem_dmabuf.c index f9b5162d9260..0d65ce146fc4 100644 --- a/drivers/infiniband/core/umem_dmabuf.c +++ b/drivers/infiniband/core/umem_dmabuf.c @@ -168,6 +168,10 @@ void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf) { struct dma_buf *dmabuf = umem_dmabuf->attach->dmabuf; + dma_resv_lock(dmabuf->resv, NULL); + ib_umem_dmabuf_unmap_pages(umem_dmabuf); + dma_resv_unlock(dmabuf->resv); + dma_buf_detach(dmabuf, umem_dmabuf->attach); dma_buf_put(dmabuf); kfree(umem_dmabuf); diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h index 091bbcd16139..03fe99deea14 100644 --- a/drivers/infiniband/hw/mlx5/mlx5_ib.h +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h @@ -1285,8 +1285,7 @@ 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); +void mlx5_ib_free_odp_mr(struct mlx5_ib_mr *mr); struct ib_mr *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); @@ -1334,8 +1333,6 @@ int mlx5_mr_cache_cleanup(struct mlx5_ib_dev *dev); struct mlx5_ib_mr *mlx5_mr_cache_alloc(struct mlx5_ib_dev *dev, unsigned int entry, int access_flags); -void mlx5_mr_cache_free(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr); -int mlx5_mr_cache_invalidate(struct mlx5_ib_mr *mr); int mlx5_ib_check_mr_status(struct ib_mr *ibmr, u32 check_mask, struct ib_mr_status *mr_status); diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c index 54fd38b01a7e..6304ba54a42d 100644 --- a/drivers/infiniband/hw/mlx5/mr.c +++ b/drivers/infiniband/hw/mlx5/mr.c @@ -119,8 +119,6 @@ mlx5_ib_create_mkey_cb(struct mlx5_ib_dev *dev, create_mkey_callback, context); } -static void clean_mr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr); -static void dereg_mr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr); static int mr_cache_max_order(struct mlx5_ib_dev *dev); static void queue_adjust_cache_locked(struct mlx5_cache_ent *ent); @@ -627,30 +625,10 @@ static struct mlx5_ib_mr *get_cache_mr(struct mlx5_cache_ent *req_ent) return NULL; } -static void detach_mr_from_cache(struct mlx5_ib_mr *mr) +static void mlx5_mr_cache_free(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr) { struct mlx5_cache_ent *ent = mr->cache_ent; - mr->cache_ent = NULL; - spin_lock_irq(&ent->lock); - ent->total_mrs--; - spin_unlock_irq(&ent->lock); -} - -void mlx5_mr_cache_free(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr) -{ - struct mlx5_cache_ent *ent = mr->cache_ent; - - if (!ent) - return; - - if (mlx5_mr_cache_invalidate(mr)) { - detach_mr_from_cache(mr); - destroy_mkey(dev, mr); - kfree(mr); - return; - } - spin_lock_irq(&ent->lock); list_add_tail(&mr->list, &ent->head); ent->available_mrs++; @@ -1503,7 +1481,7 @@ static struct ib_mr *create_real_mr(struct ib_pd *pd, struct ib_umem *umem, */ err = mlx5_ib_update_mr_pas(mr, MLX5_IB_UPD_XLT_ENABLE); if (err) { - dereg_mr(dev, mr); + mlx5_ib_dereg_mr(&mr->ibmr, NULL); return ERR_PTR(err); } } @@ -1560,7 +1538,7 @@ static struct ib_mr *create_user_odp_mr(struct ib_pd *pd, u64 start, u64 length, return &mr->ibmr; err_dereg_mr: - dereg_mr(dev, mr); + mlx5_ib_dereg_mr(&mr->ibmr, NULL); return ERR_PTR(err); } @@ -1657,7 +1635,7 @@ struct ib_mr *mlx5_ib_reg_user_mr_dmabuf(struct ib_pd *pd, u64 offset, return &mr->ibmr; err_dereg_mr: - dereg_mr(dev, mr); + mlx5_ib_dereg_mr(&mr->ibmr, NULL); return ERR_PTR(err); } @@ -1669,7 +1647,7 @@ err_dereg_mr: * and any DMA inprogress will be completed. Failure of this function * indicates the HW has failed catastrophically. */ -int mlx5_mr_cache_invalidate(struct mlx5_ib_mr *mr) +static int mlx5_mr_cache_invalidate(struct mlx5_ib_mr *mr) { struct mlx5_umr_wr umrwr = {}; @@ -1941,69 +1919,82 @@ mlx5_free_priv_descs(struct mlx5_ib_mr *mr) } } -static void clean_mr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr) +int mlx5_ib_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata) { - if (mr->ibmr.type == IB_MR_TYPE_INTEGRITY) { + struct mlx5_ib_mr *mr = to_mmr(ibmr); + struct mlx5_ib_dev *dev = to_mdev(ibmr->device); + int rc; + + /* + * Any async use of the mr must hold the refcount, once the refcount + * goes to zero no other thread, such as ODP page faults, prefetch, any + * UMR activity, etc can touch the mkey. Thus it is safe to destroy it. + */ + if (IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING) && + refcount_read(&mr->mmkey.usecount) != 0 && + xa_erase(&mr_to_mdev(mr)->odp_mkeys, mlx5_base_mkey(mr->mmkey.key))) + mlx5r_deref_wait_odp_mkey(&mr->mmkey); + + if (ibmr->type == IB_MR_TYPE_INTEGRITY) { + xa_cmpxchg(&dev->sig_mrs, mlx5_base_mkey(mr->mmkey.key), ibmr, + NULL, GFP_KERNEL); + + if (mr->mtt_mr) { + rc = mlx5_ib_dereg_mr(&mr->mtt_mr->ibmr, NULL); + if (rc) + return rc; + mr->mtt_mr = NULL; + } + if (mr->klm_mr) { + mlx5_ib_dereg_mr(&mr->klm_mr->ibmr, NULL); + if (rc) + return rc; + mr->klm_mr = NULL; + } + if (mlx5_core_destroy_psv(dev->mdev, mr->sig->psv_memory.psv_idx)) mlx5_ib_warn(dev, "failed to destroy mem psv %d\n", mr->sig->psv_memory.psv_idx); - if (mlx5_core_destroy_psv(dev->mdev, - mr->sig->psv_wire.psv_idx)) + if (mlx5_core_destroy_psv(dev->mdev, mr->sig->psv_wire.psv_idx)) mlx5_ib_warn(dev, "failed to destroy wire psv %d\n", mr->sig->psv_wire.psv_idx); - xa_erase(&dev->sig_mrs, mlx5_base_mkey(mr->mmkey.key)); kfree(mr->sig); mr->sig = NULL; } + /* Stop DMA */ + if (mr->cache_ent) { + if (mlx5_mr_cache_invalidate(mr)) { + spin_lock_irq(&mr->cache_ent->lock); + mr->cache_ent->total_mrs--; + spin_unlock_irq(&mr->cache_ent->lock); + mr->cache_ent = NULL; + } + } if (!mr->cache_ent) { - destroy_mkey(dev, mr); - mlx5_free_priv_descs(mr); + rc = destroy_mkey(to_mdev(mr->ibmr.device), mr); + if (rc) + return rc; } -} - -static void dereg_mr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr) -{ - struct ib_umem *umem = mr->umem; - /* Stop all DMA */ - if (is_odp_mr(mr)) - mlx5_ib_fence_odp_mr(mr); - else if (is_dmabuf_mr(mr)) - mlx5_ib_fence_dmabuf_mr(mr); - else - clean_mr(dev, mr); + if (mr->umem) { + bool is_odp = is_odp_mr(mr); - if (umem) { - if (!is_odp_mr(mr)) - atomic_sub(ib_umem_num_pages(umem), + if (!is_odp) + atomic_sub(ib_umem_num_pages(mr->umem), &dev->mdev->priv.reg_pages); - ib_umem_release(umem); + ib_umem_release(mr->umem); + if (is_odp) + mlx5_ib_free_odp_mr(mr); } - if (mr->cache_ent) + if (mr->cache_ent) { mlx5_mr_cache_free(dev, mr); - else + } else { + mlx5_free_priv_descs(mr); kfree(mr); -} - -int mlx5_ib_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata) -{ - struct mlx5_ib_mr *mmr = to_mmr(ibmr); - - if (ibmr->type == IB_MR_TYPE_INTEGRITY) { - dereg_mr(to_mdev(mmr->mtt_mr->ibmr.device), mmr->mtt_mr); - dereg_mr(to_mdev(mmr->klm_mr->ibmr.device), mmr->klm_mr); - } - - if (is_odp_mr(mmr) && to_ib_umem_odp(mmr->umem)->is_implicit_odp) { - mlx5_ib_free_implicit_mr(mmr); - return 0; } - - dereg_mr(to_mdev(ibmr->device), mmr); - return 0; } @@ -2175,10 +2166,10 @@ err_free_descs: destroy_mkey(dev, mr); mlx5_free_priv_descs(mr); err_free_mtt_mr: - dereg_mr(to_mdev(mr->mtt_mr->ibmr.device), mr->mtt_mr); + mlx5_ib_dereg_mr(&mr->mtt_mr->ibmr, NULL); mr->mtt_mr = NULL; err_free_klm_mr: - dereg_mr(to_mdev(mr->klm_mr->ibmr.device), mr->klm_mr); + mlx5_ib_dereg_mr(&mr->klm_mr->ibmr, NULL); mr->klm_mr = NULL; err_destroy_psv: if (mlx5_core_destroy_psv(dev->mdev, mr->sig->psv_memory.psv_idx)) diff --git a/drivers/infiniband/hw/mlx5/odp.c b/drivers/infiniband/hw/mlx5/odp.c index d98755e78362..3008d1539ad4 100644 --- a/drivers/infiniband/hw/mlx5/odp.c +++ b/drivers/infiniband/hw/mlx5/odp.c @@ -181,63 +181,29 @@ void mlx5_odp_populate_xlt(void *xlt, size_t idx, size_t nentries, } } -static void dma_fence_odp_mr(struct mlx5_ib_mr *mr) -{ - struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem); - - /* Ensure mlx5_ib_invalidate_range() will not touch the MR any more */ - mutex_lock(&odp->umem_mutex); - if (odp->npages) { - mlx5_mr_cache_invalidate(mr); - ib_umem_odp_unmap_dma_pages(odp, ib_umem_start(odp), - ib_umem_end(odp)); - WARN_ON(odp->npages); - } - odp->private = NULL; - mutex_unlock(&odp->umem_mutex); - - if (!mr->cache_ent) { - mlx5_core_destroy_mkey(mr_to_mdev(mr)->mdev, &mr->mmkey); - WARN_ON(mr->descs); - } -} - /* * This must be called after the mr has been removed from implicit_children. * NOTE: The MR does not necessarily have to be * empty here, parallel page faults could have raced with the free process and * added pages to it. */ -static void free_implicit_child_mr(struct mlx5_ib_mr *mr, bool need_imr_xlt) +static void free_implicit_child_mr_work(struct work_struct *work) { + struct mlx5_ib_mr *mr = + container_of(work, struct mlx5_ib_mr, odp_destroy.work); struct mlx5_ib_mr *imr = mr->parent; struct ib_umem_odp *odp_imr = to_ib_umem_odp(imr->umem); struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem); - unsigned long idx = ib_umem_start(odp) >> MLX5_IMR_MTT_SHIFT; mlx5r_deref_wait_odp_mkey(&mr->mmkey); - if (need_imr_xlt) { - mutex_lock(&odp_imr->umem_mutex); - mlx5_ib_update_xlt(mr->parent, idx, 1, 0, - MLX5_IB_UPD_XLT_INDIRECT | - MLX5_IB_UPD_XLT_ATOMIC); - mutex_unlock(&odp_imr->umem_mutex); - } - - dma_fence_odp_mr(mr); - - mlx5_mr_cache_free(mr_to_mdev(mr), mr); - ib_umem_odp_release(odp); -} - -static void free_implicit_child_mr_work(struct work_struct *work) -{ - struct mlx5_ib_mr *mr = - container_of(work, struct mlx5_ib_mr, odp_destroy.work); - struct mlx5_ib_mr *imr = mr->parent; + mutex_lock(&odp_imr->umem_mutex); + mlx5_ib_update_xlt(mr->parent, ib_umem_start(odp) >> MLX5_IMR_MTT_SHIFT, + 1, 0, + MLX5_IB_UPD_XLT_INDIRECT | MLX5_IB_UPD_XLT_ATOMIC); + mutex_unlock(&odp_imr->umem_mutex); + mlx5_ib_dereg_mr(&mr->ibmr, NULL); - free_implicit_child_mr(mr, true); mlx5r_deref_odp_mkey(&imr->mmkey); } @@ -454,8 +420,10 @@ static struct mlx5_ib_mr *implicit_get_child_mr(struct mlx5_ib_mr *imr, ret = mr = mlx5_mr_cache_alloc( mr_to_mdev(imr), MLX5_IMR_MTT_CACHE_ENTRY, imr->access_flags); - if (IS_ERR(mr)) - goto out_umem; + if (IS_ERR(mr)) { + ib_umem_odp_release(odp); + return mr; + } mr->ibmr.pd = imr->ibmr.pd; mr->ibmr.device = &mr_to_mdev(imr)->ib_dev; @@ -505,9 +473,7 @@ static struct mlx5_ib_mr *implicit_get_child_mr(struct mlx5_ib_mr *imr, out_lock: xa_unlock(&imr->implicit_children); out_mr: - mlx5_mr_cache_free(mr_to_mdev(imr), mr); -out_umem: - ib_umem_odp_release(odp); + mlx5_ib_dereg_mr(&mr->ibmr, NULL); return ret; } @@ -530,8 +496,8 @@ struct mlx5_ib_mr *mlx5_ib_alloc_implicit_mr(struct mlx5_ib_pd *pd, imr = mlx5_mr_cache_alloc(dev, MLX5_IMR_KSM_CACHE_ENTRY, access_flags); if (IS_ERR(imr)) { - err = PTR_ERR(imr); - goto out_umem; + ib_umem_odp_release(umem_odp); + return imr; } imr->ibmr.pd = &pd->ibpd; @@ -561,93 +527,22 @@ struct mlx5_ib_mr *mlx5_ib_alloc_implicit_mr(struct mlx5_ib_pd *pd, return imr; out_mr: mlx5_ib_err(dev, "Failed to register MKEY %d\n", err); - mlx5_mr_cache_free(dev, imr); -out_umem: - ib_umem_odp_release(umem_odp); + mlx5_ib_dereg_mr(&imr->ibmr, NULL); return ERR_PTR(err); } -void mlx5_ib_free_implicit_mr(struct mlx5_ib_mr *imr) +void mlx5_ib_free_odp_mr(struct mlx5_ib_mr *mr) { - struct ib_umem_odp *odp_imr = to_ib_umem_odp(imr->umem); - struct mlx5_ib_dev *dev = mr_to_mdev(imr); struct mlx5_ib_mr *mtt; unsigned long idx; - xa_erase(&dev->odp_mkeys, mlx5_base_mkey(imr->mmkey.key)); /* - * All work on the prefetch list must be completed, xa_erase() prevented - * new work from being created. + * If this is an implicit MR it is already invalidated so we can just + * delete the children mkeys. */ - mlx5r_deref_wait_odp_mkey(&imr->mmkey); - /* - * At this point it is forbidden for any other thread to enter - * pagefault_mr() on this imr. It is already forbidden to call - * pagefault_mr() on an implicit child. Due to this additions to - * implicit_children are prevented. - * In addition, any new call to destroy_unused_implicit_child_mr() - * may return immediately. - */ - - /* - * Fence the imr before we destroy the children. This allows us to - * skip updating the XLT of the imr during destroy of the child mkey - * the imr points to. - */ - mlx5_mr_cache_invalidate(imr); - - xa_for_each(&imr->implicit_children, idx, mtt) { - xa_erase(&imr->implicit_children, idx); - free_implicit_child_mr(mtt, false); - } - - mlx5_mr_cache_free(dev, imr); - ib_umem_odp_release(odp_imr); -} - -/** - * mlx5_ib_fence_odp_mr - Stop all access to the ODP MR - * @mr: to fence - * - * On return no parallel threads will be touching this MR and no DMA will be - * active. - */ -void mlx5_ib_fence_odp_mr(struct mlx5_ib_mr *mr) -{ - /* Prevent new page faults and prefetch requests from succeeding */ - xa_erase(&mr_to_mdev(mr)->odp_mkeys, mlx5_base_mkey(mr->mmkey.key)); - - /* Wait for all running page-fault handlers to finish. */ - mlx5r_deref_wait_odp_mkey(&mr->mmkey); - - 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_to_mdev(mr)->odp_mkeys, mlx5_base_mkey(mr->mmkey.key)); - - mlx5r_deref_wait_odp_mkey(&mr->mmkey); - - 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_to_mdev(mr)->mdev, &mr->mmkey); - WARN_ON(mr->descs); + xa_for_each(&mr->implicit_children, idx, mtt) { + xa_erase(&mr->implicit_children, idx); + mlx5_ib_dereg_mr(&mtt->ibmr, NULL); } }