From 6aec21f6a8322fa8d43df3ea7f051dfd8967f1b9 Mon Sep 17 00:00:00 2001 From: Haggai Eran Date: Thu, 11 Dec 2014 17:04:23 +0200 Subject: [PATCH] IB/mlx5: Page faults handling infrastructure * Refactor MR registration and cleanup, and fix reg_pages accounting. * Create a work queue to handle page fault events in a kthread context. * Register a fault handler to get events from the core for each QP. The registered fault handler is empty in this patch, and only a later patch implements it. Signed-off-by: Sagi Grimberg Signed-off-by: Shachar Raindel Signed-off-by: Haggai Eran Signed-off-by: Roland Dreier --- drivers/infiniband/hw/mlx5/main.c | 31 +++++- drivers/infiniband/hw/mlx5/mlx5_ib.h | 67 ++++++++++++- drivers/infiniband/hw/mlx5/mr.c | 47 ++++++--- drivers/infiniband/hw/mlx5/odp.c | 145 +++++++++++++++++++++++++++ drivers/infiniband/hw/mlx5/qp.c | 26 ++++- include/linux/mlx5/driver.h | 2 +- 6 files changed, 295 insertions(+), 23 deletions(-) diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c index e6d775f2446d..a801baa79c8e 100644 --- a/drivers/infiniband/hw/mlx5/main.c +++ b/drivers/infiniband/hw/mlx5/main.c @@ -864,7 +864,7 @@ static ssize_t show_reg_pages(struct device *device, struct mlx5_ib_dev *dev = container_of(device, struct mlx5_ib_dev, ib_dev.dev); - return sprintf(buf, "%d\n", dev->mdev->priv.reg_pages); + return sprintf(buf, "%d\n", atomic_read(&dev->mdev->priv.reg_pages)); } static ssize_t show_hca(struct device *device, struct device_attribute *attr, @@ -1389,16 +1389,19 @@ static void *mlx5_ib_add(struct mlx5_core_dev *mdev) goto err_eqs; mutex_init(&dev->cap_mask_mutex); - spin_lock_init(&dev->mr_lock); err = create_dev_resources(&dev->devr); if (err) goto err_eqs; - err = ib_register_device(&dev->ib_dev, NULL); + err = mlx5_ib_odp_init_one(dev); if (err) goto err_rsrc; + err = ib_register_device(&dev->ib_dev, NULL); + if (err) + goto err_odp; + err = create_umr_res(dev); if (err) goto err_dev; @@ -1420,6 +1423,9 @@ err_umrc: err_dev: ib_unregister_device(&dev->ib_dev); +err_odp: + mlx5_ib_odp_remove_one(dev); + err_rsrc: destroy_dev_resources(&dev->devr); @@ -1435,8 +1441,10 @@ err_dealloc: static void mlx5_ib_remove(struct mlx5_core_dev *mdev, void *context) { struct mlx5_ib_dev *dev = context; + ib_unregister_device(&dev->ib_dev); destroy_umrc_res(dev); + mlx5_ib_odp_remove_one(dev); destroy_dev_resources(&dev->devr); free_comp_eqs(dev); ib_dealloc_device(&dev->ib_dev); @@ -1450,15 +1458,30 @@ static struct mlx5_interface mlx5_ib_interface = { static int __init mlx5_ib_init(void) { + int err; + if (deprecated_prof_sel != 2) pr_warn("prof_sel is deprecated for mlx5_ib, set it for mlx5_core\n"); - return mlx5_register_interface(&mlx5_ib_interface); + err = mlx5_ib_odp_init(); + if (err) + return err; + + err = mlx5_register_interface(&mlx5_ib_interface); + if (err) + goto clean_odp; + + return err; + +clean_odp: + mlx5_ib_odp_cleanup(); + return err; } static void __exit mlx5_ib_cleanup(void) { mlx5_unregister_interface(&mlx5_ib_interface); + mlx5_ib_odp_cleanup(); } module_init(mlx5_ib_init); diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h index 6856e27bfb6a..c6ceec3e3d6a 100644 --- a/drivers/infiniband/hw/mlx5/mlx5_ib.h +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h @@ -149,6 +149,29 @@ enum { MLX5_QP_EMPTY }; +/* + * Connect-IB can trigger up to four concurrent pagefaults + * per-QP. + */ +enum mlx5_ib_pagefault_context { + MLX5_IB_PAGEFAULT_RESPONDER_READ, + MLX5_IB_PAGEFAULT_REQUESTOR_READ, + MLX5_IB_PAGEFAULT_RESPONDER_WRITE, + MLX5_IB_PAGEFAULT_REQUESTOR_WRITE, + MLX5_IB_PAGEFAULT_CONTEXTS +}; + +static inline enum mlx5_ib_pagefault_context + mlx5_ib_get_pagefault_context(struct mlx5_pagefault *pagefault) +{ + return pagefault->flags & (MLX5_PFAULT_REQUESTOR | MLX5_PFAULT_WRITE); +} + +struct mlx5_ib_pfault { + struct work_struct work; + struct mlx5_pagefault mpfault; +}; + struct mlx5_ib_qp { struct ib_qp ibqp; struct mlx5_core_qp mqp; @@ -194,6 +217,21 @@ struct mlx5_ib_qp { /* Store signature errors */ bool signature_en; + +#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING + /* + * A flag that is true for QP's that are in a state that doesn't + * allow page faults, and shouldn't schedule any more faults. + */ + int disable_page_faults; + /* + * The disable_page_faults_lock protects a QP's disable_page_faults + * field, allowing for a thread to atomically check whether the QP + * allows page faults, and if so schedule a page fault. + */ + spinlock_t disable_page_faults_lock; + struct mlx5_ib_pfault pagefaults[MLX5_IB_PAGEFAULT_CONTEXTS]; +#endif }; struct mlx5_ib_cq_buf { @@ -392,13 +430,17 @@ struct mlx5_ib_dev { struct umr_common umrc; /* sync used page count stats */ - spinlock_t mr_lock; struct mlx5_ib_resources devr; struct mlx5_mr_cache cache; struct timer_list delay_timer; int fill_delay; #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING struct ib_odp_caps odp_caps; + /* + * Sleepable RCU that prevents destruction of MRs while they are still + * being used by a page fault handler. + */ + struct srcu_struct mr_srcu; #endif }; @@ -575,12 +617,33 @@ int mlx5_ib_check_mr_status(struct ib_mr *ibmr, u32 check_mask, struct ib_mr_status *mr_status); #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING +extern struct workqueue_struct *mlx5_ib_page_fault_wq; + int mlx5_ib_internal_query_odp_caps(struct mlx5_ib_dev *dev); -#else +void mlx5_ib_mr_pfault_handler(struct mlx5_ib_qp *qp, + struct mlx5_ib_pfault *pfault); +void mlx5_ib_odp_create_qp(struct mlx5_ib_qp *qp); +int mlx5_ib_odp_init_one(struct mlx5_ib_dev *ibdev); +void mlx5_ib_odp_remove_one(struct mlx5_ib_dev *ibdev); +int __init mlx5_ib_odp_init(void); +void mlx5_ib_odp_cleanup(void); +void mlx5_ib_qp_disable_pagefaults(struct mlx5_ib_qp *qp); +void mlx5_ib_qp_enable_pagefaults(struct mlx5_ib_qp *qp); + +#else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */ static inline int mlx5_ib_internal_query_odp_caps(struct mlx5_ib_dev *dev) { return 0; } + +static inline void mlx5_ib_odp_create_qp(struct mlx5_ib_qp *qp) {} +static inline int mlx5_ib_odp_init_one(struct mlx5_ib_dev *ibdev) { return 0; } +static inline void mlx5_ib_odp_remove_one(struct mlx5_ib_dev *ibdev) {} +static inline int mlx5_ib_odp_init(void) { return 0; } +static inline void mlx5_ib_odp_cleanup(void) {} +static inline void mlx5_ib_qp_disable_pagefaults(struct mlx5_ib_qp *qp) {} +static inline void mlx5_ib_qp_enable_pagefaults(struct mlx5_ib_qp *qp) {} + #endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */ static inline void init_query_mad(struct ib_smp *mad) diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c index 38b06267798e..922ac85b7198 100644 --- a/drivers/infiniband/hw/mlx5/mr.c +++ b/drivers/infiniband/hw/mlx5/mr.c @@ -52,6 +52,8 @@ static __be64 mlx5_ib_update_mtt_emergency_buffer[ static DEFINE_MUTEX(mlx5_ib_update_mtt_emergency_buffer_mutex); #endif +static int clean_mr(struct mlx5_ib_mr *mr); + static int order2idx(struct mlx5_ib_dev *dev, int order) { struct mlx5_mr_cache *cache = &dev->cache; @@ -1049,6 +1051,10 @@ struct ib_mr *mlx5_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length, mlx5_ib_dbg(dev, "cache empty for order %d", order); mr = NULL; } + } else if (access_flags & IB_ACCESS_ON_DEMAND) { + err = -EINVAL; + pr_err("Got MR registration for ODP MR > 512MB, not supported for Connect-IB"); + goto error; } if (!mr) @@ -1064,9 +1070,7 @@ struct ib_mr *mlx5_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length, mr->umem = umem; mr->npages = npages; - spin_lock(&dev->mr_lock); - dev->mdev->priv.reg_pages += npages; - spin_unlock(&dev->mr_lock); + atomic_add(npages, &dev->mdev->priv.reg_pages); mr->ibmr.lkey = mr->mmr.key; mr->ibmr.rkey = mr->mmr.key; @@ -1110,12 +1114,9 @@ error: return err; } -int mlx5_ib_dereg_mr(struct ib_mr *ibmr) +static int clean_mr(struct mlx5_ib_mr *mr) { - struct mlx5_ib_dev *dev = to_mdev(ibmr->device); - struct mlx5_ib_mr *mr = to_mmr(ibmr); - struct ib_umem *umem = mr->umem; - int npages = mr->npages; + struct mlx5_ib_dev *dev = to_mdev(mr->ibmr.device); int umred = mr->umred; int err; @@ -1135,19 +1136,35 @@ int mlx5_ib_dereg_mr(struct ib_mr *ibmr) free_cached_mr(dev, mr); } - if (umem) { - ib_umem_release(umem); - spin_lock(&dev->mr_lock); - dev->mdev->priv.reg_pages -= npages; - spin_unlock(&dev->mr_lock); - } - if (!umred) kfree(mr); return 0; } +int mlx5_ib_dereg_mr(struct ib_mr *ibmr) +{ + struct mlx5_ib_dev *dev = to_mdev(ibmr->device); + struct mlx5_ib_mr *mr = to_mmr(ibmr); + int npages = mr->npages; + struct ib_umem *umem = mr->umem; + +#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING + if (umem) + /* Wait for all running page-fault handlers to finish. */ + synchronize_srcu(&dev->mr_srcu); +#endif + + clean_mr(mr); + + if (umem) { + ib_umem_release(umem); + atomic_sub(npages, &dev->mdev->priv.reg_pages); + } + + return 0; +} + struct ib_mr *mlx5_ib_create_mr(struct ib_pd *pd, struct ib_mr_init_attr *mr_init_attr) { diff --git a/drivers/infiniband/hw/mlx5/odp.c b/drivers/infiniband/hw/mlx5/odp.c index 66c39ee16aff..63bbdba396f1 100644 --- a/drivers/infiniband/hw/mlx5/odp.c +++ b/drivers/infiniband/hw/mlx5/odp.c @@ -32,6 +32,8 @@ #include "mlx5_ib.h" +struct workqueue_struct *mlx5_ib_page_fault_wq; + #define COPY_ODP_BIT_MLX_TO_IB(reg, ib_caps, field_name, bit_name) do { \ if (be32_to_cpu(reg.field_name) & MLX5_ODP_SUPPORT_##bit_name) \ ib_caps->field_name |= IB_ODP_SUPPORT_##bit_name; \ @@ -58,3 +60,146 @@ int mlx5_ib_internal_query_odp_caps(struct mlx5_ib_dev *dev) out: return err; } + +static struct mlx5_ib_mr *mlx5_ib_odp_find_mr_lkey(struct mlx5_ib_dev *dev, + u32 key) +{ + u32 base_key = mlx5_base_mkey(key); + struct mlx5_core_mr *mmr = __mlx5_mr_lookup(dev->mdev, base_key); + + if (!mmr || mmr->key != key) + return NULL; + + return container_of(mmr, struct mlx5_ib_mr, mmr); +} + +static void mlx5_ib_page_fault_resume(struct mlx5_ib_qp *qp, + struct mlx5_ib_pfault *pfault, + int error) { + struct mlx5_ib_dev *dev = to_mdev(qp->ibqp.pd->device); + int ret = mlx5_core_page_fault_resume(dev->mdev, qp->mqp.qpn, + pfault->mpfault.flags, + error); + if (ret) + pr_err("Failed to resolve the page fault on QP 0x%x\n", + qp->mqp.qpn); +} + +void mlx5_ib_mr_pfault_handler(struct mlx5_ib_qp *qp, + struct mlx5_ib_pfault *pfault) +{ + u8 event_subtype = pfault->mpfault.event_subtype; + + switch (event_subtype) { + default: + pr_warn("Invalid page fault event subtype: 0x%x\n", + event_subtype); + mlx5_ib_page_fault_resume(qp, pfault, 1); + break; + } +} + +static void mlx5_ib_qp_pfault_action(struct work_struct *work) +{ + struct mlx5_ib_pfault *pfault = container_of(work, + struct mlx5_ib_pfault, + work); + enum mlx5_ib_pagefault_context context = + mlx5_ib_get_pagefault_context(&pfault->mpfault); + struct mlx5_ib_qp *qp = container_of(pfault, struct mlx5_ib_qp, + pagefaults[context]); + mlx5_ib_mr_pfault_handler(qp, pfault); +} + +void mlx5_ib_qp_disable_pagefaults(struct mlx5_ib_qp *qp) +{ + unsigned long flags; + + spin_lock_irqsave(&qp->disable_page_faults_lock, flags); + qp->disable_page_faults = 1; + spin_unlock_irqrestore(&qp->disable_page_faults_lock, flags); + + /* + * Note that at this point, we are guarenteed that no more + * work queue elements will be posted to the work queue with + * the QP we are closing. + */ + flush_workqueue(mlx5_ib_page_fault_wq); +} + +void mlx5_ib_qp_enable_pagefaults(struct mlx5_ib_qp *qp) +{ + unsigned long flags; + + spin_lock_irqsave(&qp->disable_page_faults_lock, flags); + qp->disable_page_faults = 0; + spin_unlock_irqrestore(&qp->disable_page_faults_lock, flags); +} + +static void mlx5_ib_pfault_handler(struct mlx5_core_qp *qp, + struct mlx5_pagefault *pfault) +{ + /* + * Note that we will only get one fault event per QP per context + * (responder/initiator, read/write), until we resolve the page fault + * with the mlx5_ib_page_fault_resume command. Since this function is + * called from within the work element, there is no risk of missing + * events. + */ + struct mlx5_ib_qp *mibqp = to_mibqp(qp); + enum mlx5_ib_pagefault_context context = + mlx5_ib_get_pagefault_context(pfault); + struct mlx5_ib_pfault *qp_pfault = &mibqp->pagefaults[context]; + + qp_pfault->mpfault = *pfault; + + /* No need to stop interrupts here since we are in an interrupt */ + spin_lock(&mibqp->disable_page_faults_lock); + if (!mibqp->disable_page_faults) + queue_work(mlx5_ib_page_fault_wq, &qp_pfault->work); + spin_unlock(&mibqp->disable_page_faults_lock); +} + +void mlx5_ib_odp_create_qp(struct mlx5_ib_qp *qp) +{ + int i; + + qp->disable_page_faults = 1; + spin_lock_init(&qp->disable_page_faults_lock); + + qp->mqp.pfault_handler = mlx5_ib_pfault_handler; + + for (i = 0; i < MLX5_IB_PAGEFAULT_CONTEXTS; ++i) + INIT_WORK(&qp->pagefaults[i].work, mlx5_ib_qp_pfault_action); +} + +int mlx5_ib_odp_init_one(struct mlx5_ib_dev *ibdev) +{ + int ret; + + ret = init_srcu_struct(&ibdev->mr_srcu); + if (ret) + return ret; + + return 0; +} + +void mlx5_ib_odp_remove_one(struct mlx5_ib_dev *ibdev) +{ + cleanup_srcu_struct(&ibdev->mr_srcu); +} + +int __init mlx5_ib_odp_init(void) +{ + mlx5_ib_page_fault_wq = + create_singlethread_workqueue("mlx5_ib_page_faults"); + if (!mlx5_ib_page_fault_wq) + return -ENOMEM; + + return 0; +} + +void mlx5_ib_odp_cleanup(void) +{ + destroy_workqueue(mlx5_ib_page_fault_wq); +} diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c index 9783c3342dbf..be0cd358b080 100644 --- a/drivers/infiniband/hw/mlx5/qp.c +++ b/drivers/infiniband/hw/mlx5/qp.c @@ -876,6 +876,8 @@ static int create_qp_common(struct mlx5_ib_dev *dev, struct ib_pd *pd, int inlen = sizeof(*in); int err; + mlx5_ib_odp_create_qp(qp); + gen = &dev->mdev->caps.gen; mutex_init(&qp->mutex); spin_lock_init(&qp->sq.lock); @@ -1160,11 +1162,13 @@ static void destroy_qp_common(struct mlx5_ib_dev *dev, struct mlx5_ib_qp *qp) in = kzalloc(sizeof(*in), GFP_KERNEL); if (!in) return; - if (qp->state != IB_QPS_RESET) + if (qp->state != IB_QPS_RESET) { + mlx5_ib_qp_disable_pagefaults(qp); if (mlx5_core_qp_modify(dev->mdev, to_mlx5_state(qp->state), MLX5_QP_STATE_RST, in, sizeof(*in), &qp->mqp)) mlx5_ib_warn(dev, "mlx5_ib: modify QP %06x to RESET failed\n", qp->mqp.qpn); + } get_cqs(qp, &send_cq, &recv_cq); @@ -1712,6 +1716,15 @@ static int __mlx5_ib_modify_qp(struct ib_qp *ibqp, if (mlx5_st < 0) goto out; + /* If moving to a reset or error state, we must disable page faults on + * this QP and flush all current page faults. Otherwise a stale page + * fault may attempt to work on this QP after it is reset and moved + * again to RTS, and may cause the driver and the device to get out of + * sync. */ + if (cur_state != IB_QPS_RESET && cur_state != IB_QPS_ERR && + (new_state == IB_QPS_RESET || new_state == IB_QPS_ERR)) + mlx5_ib_qp_disable_pagefaults(qp); + optpar = ib_mask_to_mlx5_opt(attr_mask); optpar &= opt_mask[mlx5_cur][mlx5_new][mlx5_st]; in->optparam = cpu_to_be32(optpar); @@ -1721,6 +1734,9 @@ static int __mlx5_ib_modify_qp(struct ib_qp *ibqp, if (err) goto out; + if (cur_state == IB_QPS_RESET && new_state == IB_QPS_INIT) + mlx5_ib_qp_enable_pagefaults(qp); + qp->state = new_state; if (attr_mask & IB_QP_ACCESS_FLAGS) @@ -3026,6 +3042,14 @@ int mlx5_ib_query_qp(struct ib_qp *ibqp, struct ib_qp_attr *qp_attr, int qp_attr int mlx5_state; int err = 0; +#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING + /* + * Wait for any outstanding page faults, in case the user frees memory + * based upon this query's result. + */ + flush_workqueue(mlx5_ib_page_fault_wq); +#endif + mutex_lock(&qp->mutex); outb = kzalloc(sizeof(*outb), GFP_KERNEL); if (!outb) { diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h index 7088dcd19214..166d9315fe4b 100644 --- a/include/linux/mlx5/driver.h +++ b/include/linux/mlx5/driver.h @@ -474,7 +474,7 @@ struct mlx5_priv { struct workqueue_struct *pg_wq; struct rb_root page_root; int fw_pages; - int reg_pages; + atomic_t reg_pages; struct list_head free_list; struct mlx5_core_health health;