From: Mark Zhang Date: Mon, 16 Jun 2025 08:26:20 +0000 (+0300) Subject: RDMA/core: Add driver APIs pre_destroy_cq() and post_destroy_cq() X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5a2a5b65d5d67279be9e1f0e4b9baf39ee594cb1;p=thirdparty%2Flinux.git RDMA/core: Add driver APIs pre_destroy_cq() and post_destroy_cq() Currently in ib_free_cq, it disables IRQ or cancel the CQ work before driver destroy_cq. This isn't good as a new IRQ or a CQ work can be submitted immediately after disabling IRQ or canceling CQ work, which may run concurrently with destroy_cq and cause crashes. The right flow should be: 1. Driver disables CQ to make sure no new CQ event will be submitted; 2. Disables IRQ or Cancels CQ work in core layer, to make sure no CQ polling work is running; 3. Free all resources to destroy the CQ. This patch adds 2 driver APIs: - pre_destroy_cq(): Disable a CQ to prevent it from generating any new work completions, but not free any kernel resources; - post_destroy_cq(): Free all kernel resources. In ib_free_cq, the IRQ is disabled or CQ work is canceled after pre_destroy_cq, and before post_destroy_cq. Fixes: 14d3a3b2498e ("IB: add a proper completion queue abstraction") Signed-off-by: Mark Zhang Link: https://patch.msgid.link/b5f7ae3d75f44a3e15ff3f4eb2bbdea13e06b97f.1750062328.git.leon@kernel.org Signed-off-by: Leon Romanovsky --- diff --git a/drivers/infiniband/core/cq.c b/drivers/infiniband/core/cq.c index a70876a0a2312..584537c71545c 100644 --- a/drivers/infiniband/core/cq.c +++ b/drivers/infiniband/core/cq.c @@ -317,13 +317,18 @@ EXPORT_SYMBOL(__ib_alloc_cq_any); */ void ib_free_cq(struct ib_cq *cq) { - int ret; + int ret = 0; if (WARN_ON_ONCE(atomic_read(&cq->usecnt))) return; if (WARN_ON_ONCE(cq->cqe_used)) return; + if (cq->device->ops.pre_destroy_cq) { + ret = cq->device->ops.pre_destroy_cq(cq); + WARN_ONCE(ret, "Disable of kernel CQ shouldn't fail"); + } + switch (cq->poll_ctx) { case IB_POLL_DIRECT: break; @@ -340,7 +345,10 @@ void ib_free_cq(struct ib_cq *cq) rdma_dim_destroy(cq); trace_cq_free(cq); - ret = cq->device->ops.destroy_cq(cq, NULL); + if (cq->device->ops.post_destroy_cq) + cq->device->ops.post_destroy_cq(cq); + else + ret = cq->device->ops.destroy_cq(cq, NULL); WARN_ONCE(ret, "Destroy of kernel CQ shouldn't fail"); rdma_restrack_del(&cq->res); kfree(cq->wc); diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c index d4263385850a7..468ed6bd47220 100644 --- a/drivers/infiniband/core/device.c +++ b/drivers/infiniband/core/device.c @@ -2763,8 +2763,10 @@ void ib_set_device_ops(struct ib_device *dev, const struct ib_device_ops *ops) SET_DEVICE_OP(dev_ops, modify_srq); SET_DEVICE_OP(dev_ops, modify_wq); SET_DEVICE_OP(dev_ops, peek_cq); + SET_DEVICE_OP(dev_ops, pre_destroy_cq); SET_DEVICE_OP(dev_ops, poll_cq); SET_DEVICE_OP(dev_ops, port_groups); + SET_DEVICE_OP(dev_ops, post_destroy_cq); SET_DEVICE_OP(dev_ops, post_recv); SET_DEVICE_OP(dev_ops, post_send); SET_DEVICE_OP(dev_ops, post_srq_recv); diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index af43a8d2a74ae..38f68d245fa6e 100644 --- a/include/rdma/ib_verbs.h +++ b/include/rdma/ib_verbs.h @@ -2489,6 +2489,15 @@ struct ib_device_ops { int (*modify_cq)(struct ib_cq *cq, u16 cq_count, u16 cq_period); int (*destroy_cq)(struct ib_cq *cq, struct ib_udata *udata); int (*resize_cq)(struct ib_cq *cq, int cqe, struct ib_udata *udata); + /** + * pre_destroy_cq - Prevent a cq from generating any new work + * completions, but not free any kernel resources + */ + int (*pre_destroy_cq)(struct ib_cq *cq); + /** + * post_destroy_cq - Free all kernel resources + */ + void (*post_destroy_cq)(struct ib_cq *cq); struct ib_mr *(*get_dma_mr)(struct ib_pd *pd, int mr_access_flags); struct ib_mr *(*reg_user_mr)(struct ib_pd *pd, u64 start, u64 length, u64 virt_addr, int mr_access_flags,