From: Eli Cohen Date: Wed, 18 May 2022 13:38:04 +0000 (+0300) Subject: vdpa/mlx5: Use readers/writers semaphore instead of mutex X-Git-Tag: v6.1-rc5~1169^2~58 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=759ae7f9bf1e6b7f5c9c197d7207e2be1dfd74b1;p=platform%2Fkernel%2Flinux-starfive.git vdpa/mlx5: Use readers/writers semaphore instead of mutex Reading statistics could be done intensively and by several processes concurrently. Reader's lock is sufficient in this case. Change reslock from mutex to a rwsem. Suggested-by: Si-Wei Liu Signed-off-by: Eli Cohen Message-Id: <20220518133804.1075129-7-elic@nvidia.com> Signed-off-by: Michael S. Tsirkin --- diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c index 2b815ef..57cfc64 100644 --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c @@ -155,7 +155,7 @@ struct mlx5_vdpa_net { * since memory map might change and we need to destroy and create * resources while driver in operational. */ - struct mutex reslock; + struct rw_semaphore reslock; struct mlx5_flow_table *rxft; struct mlx5_fc *rx_counter; struct mlx5_flow_handle *rx_rule_ucast; @@ -1695,7 +1695,7 @@ static void mlx5_cvq_kick_handler(struct work_struct *work) ndev = to_mlx5_vdpa_ndev(mvdev); cvq = &mvdev->cvq; - mutex_lock(&ndev->reslock); + down_write(&ndev->reslock); if (!(mvdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) goto out; @@ -1746,7 +1746,7 @@ static void mlx5_cvq_kick_handler(struct work_struct *work) } out: - mutex_unlock(&ndev->reslock); + up_write(&ndev->reslock); } static void mlx5_vdpa_kick_vq(struct vdpa_device *vdev, u16 idx) @@ -2244,7 +2244,7 @@ static int setup_driver(struct mlx5_vdpa_dev *mvdev) struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev); int err; - WARN_ON(!mutex_is_locked(&ndev->reslock)); + WARN_ON(!rwsem_is_locked(&ndev->reslock)); if (ndev->setup) { mlx5_vdpa_warn(mvdev, "setup driver called for already setup driver\n"); @@ -2292,7 +2292,7 @@ out: static void teardown_driver(struct mlx5_vdpa_net *ndev) { - WARN_ON(!mutex_is_locked(&ndev->reslock)); + WARN_ON(!rwsem_is_locked(&ndev->reslock)); if (!ndev->setup) return; @@ -2322,7 +2322,7 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status) print_status(mvdev, status, true); - mutex_lock(&ndev->reslock); + down_write(&ndev->reslock); if ((status ^ ndev->mvdev.status) & VIRTIO_CONFIG_S_DRIVER_OK) { if (status & VIRTIO_CONFIG_S_DRIVER_OK) { @@ -2338,14 +2338,14 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status) } ndev->mvdev.status = status; - mutex_unlock(&ndev->reslock); + up_write(&ndev->reslock); return; err_setup: mlx5_vdpa_destroy_mr(&ndev->mvdev); ndev->mvdev.status |= VIRTIO_CONFIG_S_FAILED; err_clear: - mutex_unlock(&ndev->reslock); + up_write(&ndev->reslock); } static int mlx5_vdpa_reset(struct vdpa_device *vdev) @@ -2356,7 +2356,7 @@ static int mlx5_vdpa_reset(struct vdpa_device *vdev) print_status(mvdev, 0, true); mlx5_vdpa_info(mvdev, "performing device reset\n"); - mutex_lock(&ndev->reslock); + down_write(&ndev->reslock); teardown_driver(ndev); clear_vqs_ready(ndev); mlx5_vdpa_destroy_mr(&ndev->mvdev); @@ -2371,7 +2371,7 @@ static int mlx5_vdpa_reset(struct vdpa_device *vdev) if (mlx5_vdpa_create_mr(mvdev, NULL)) mlx5_vdpa_warn(mvdev, "create MR failed\n"); } - mutex_unlock(&ndev->reslock); + up_write(&ndev->reslock); return 0; } @@ -2411,7 +2411,7 @@ static int mlx5_vdpa_set_map(struct vdpa_device *vdev, struct vhost_iotlb *iotlb bool change_map; int err; - mutex_lock(&ndev->reslock); + down_write(&ndev->reslock); err = mlx5_vdpa_handle_set_map(mvdev, iotlb, &change_map); if (err) { @@ -2423,7 +2423,7 @@ static int mlx5_vdpa_set_map(struct vdpa_device *vdev, struct vhost_iotlb *iotlb err = mlx5_vdpa_change_map(mvdev, iotlb); err: - mutex_unlock(&ndev->reslock); + up_write(&ndev->reslock); return err; } @@ -2442,7 +2442,6 @@ static void mlx5_vdpa_free(struct vdpa_device *vdev) mlx5_mpfs_del_mac(pfmdev, ndev->config.mac); } mlx5_vdpa_free_resources(&ndev->mvdev); - mutex_destroy(&ndev->reslock); kfree(ndev->event_cbs); kfree(ndev->vqs); } @@ -2527,7 +2526,7 @@ static int mlx5_vdpa_get_vendor_vq_stats(struct vdpa_device *vdev, u16 idx, u64 completed_desc; int err = 0; - mutex_lock(&ndev->reslock); + down_read(&ndev->reslock); if (!is_index_valid(mvdev, idx)) { NL_SET_ERR_MSG_MOD(extack, "virtqueue index is not valid"); err = -EINVAL; @@ -2566,7 +2565,7 @@ out: err = 0; out_err: - mutex_unlock(&ndev->reslock); + up_read(&ndev->reslock); return err; } @@ -2835,18 +2834,18 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name, } init_mvqs(ndev); - mutex_init(&ndev->reslock); + init_rwsem(&ndev->reslock); config = &ndev->config; if (add_config->mask & BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MTU)) { err = config_func_mtu(mdev, add_config->net.mtu); if (err) - goto err_mtu; + goto err_alloc; } err = query_mtu(mdev, &mtu); if (err) - goto err_mtu; + goto err_alloc; ndev->config.mtu = cpu_to_mlx5vdpa16(mvdev, mtu); @@ -2860,14 +2859,14 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name, } else { err = mlx5_query_nic_vport_mac_address(mdev, 0, 0, config->mac); if (err) - goto err_mtu; + goto err_alloc; } if (!is_zero_ether_addr(config->mac)) { pfmdev = pci_get_drvdata(pci_physfn(mdev->pdev)); err = mlx5_mpfs_add_mac(pfmdev, config->mac); if (err) - goto err_mtu; + goto err_alloc; ndev->mvdev.mlx_features |= BIT_ULL(VIRTIO_NET_F_MAC); } @@ -2917,8 +2916,6 @@ err_res: err_mpfs: if (!is_zero_ether_addr(config->mac)) mlx5_mpfs_del_mac(pfmdev, config->mac); -err_mtu: - mutex_destroy(&ndev->reslock); err_alloc: put_device(&mvdev->vdev.dev); return err;