From 46d18d510d78318c4aa5aaeff66782f1ec42c2ec Mon Sep 17 00:00:00 2001 From: Mukul Joshi Date: Wed, 6 Apr 2022 20:07:37 -0400 Subject: drm/amdkfd: Cleanup IO links during KFD device removal Currently, the IO-links to the device being removed from topology, are not cleared. As a result, there would be dangling links left in the KFD topology. This patch aims to fix the following: 1. Cleanup all IO links to the device being removed. 2. Ensure that node numbering in sysfs and nodes proximity domain values are consistent after the device is removed: a. Adding a device and removing a GPU device are made mutually exclusive. b. The global proximity domain counter is no longer required to be an atomic counter. A normal 32-bit counter can be used instead. 3. Update generation_count to let user-mode know that topology has changed due to device removal. CC: Shuotao Xu Reviewed-by: Shuotao Xu Reviewed-by: Felix Kuehling Signed-off-by: Mukul Joshi Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdkfd/kfd_crat.c | 4 +- drivers/gpu/drm/amd/amdkfd/kfd_priv.h | 2 + drivers/gpu/drm/amd/amdkfd/kfd_topology.c | 83 +++++++++++++++++++++++++++---- 3 files changed, 78 insertions(+), 11 deletions(-) (limited to 'drivers/gpu') diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c index 1eaabd2cb41b..afc8a7fcdad8 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c @@ -1056,7 +1056,7 @@ static int kfd_parse_subtype_iolink(struct crat_subtype_iolink *iolink, * table, add corresponded reversed direction link now. */ if (props && (iolink->flags & CRAT_IOLINK_FLAGS_BI_DIRECTIONAL)) { - to_dev = kfd_topology_device_by_proximity_domain(id_to); + to_dev = kfd_topology_device_by_proximity_domain_no_lock(id_to); if (!to_dev) return -ENODEV; /* same everything but the other direction */ @@ -2225,7 +2225,7 @@ static int kfd_create_vcrat_image_gpu(void *pcrat_image, */ if (kdev->hive_id) { for (nid = 0; nid < proximity_domain; ++nid) { - peer_dev = kfd_topology_device_by_proximity_domain(nid); + peer_dev = kfd_topology_device_by_proximity_domain_no_lock(nid); if (!peer_dev->gpu) continue; if (peer_dev->gpu->hive_id != kdev->hive_id) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h index e1b7e6afa920..8a43def1f638 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h +++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h @@ -1016,6 +1016,8 @@ int kfd_topology_add_device(struct kfd_dev *gpu); int kfd_topology_remove_device(struct kfd_dev *gpu); struct kfd_topology_device *kfd_topology_device_by_proximity_domain( uint32_t proximity_domain); +struct kfd_topology_device *kfd_topology_device_by_proximity_domain_no_lock( + uint32_t proximity_domain); struct kfd_topology_device *kfd_topology_device_by_id(uint32_t gpu_id); struct kfd_dev *kfd_device_by_id(uint32_t gpu_id); struct kfd_dev *kfd_device_by_pci_dev(const struct pci_dev *pdev); diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c index 3bdcae239bc0..8b7710b4d3ed 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c @@ -46,22 +46,32 @@ static struct list_head topology_device_list; static struct kfd_system_properties sys_props; static DECLARE_RWSEM(topology_lock); -static atomic_t topology_crat_proximity_domain; +static uint32_t topology_crat_proximity_domain; -struct kfd_topology_device *kfd_topology_device_by_proximity_domain( +struct kfd_topology_device *kfd_topology_device_by_proximity_domain_no_lock( uint32_t proximity_domain) { struct kfd_topology_device *top_dev; struct kfd_topology_device *device = NULL; - down_read(&topology_lock); - list_for_each_entry(top_dev, &topology_device_list, list) if (top_dev->proximity_domain == proximity_domain) { device = top_dev; break; } + return device; +} + +struct kfd_topology_device *kfd_topology_device_by_proximity_domain( + uint32_t proximity_domain) +{ + struct kfd_topology_device *device = NULL; + + down_read(&topology_lock); + + device = kfd_topology_device_by_proximity_domain_no_lock( + proximity_domain); up_read(&topology_lock); return device; @@ -1060,7 +1070,7 @@ int kfd_topology_init(void) down_write(&topology_lock); kfd_topology_update_device_list(&temp_topology_device_list, &topology_device_list); - atomic_set(&topology_crat_proximity_domain, sys_props.num_devices-1); + topology_crat_proximity_domain = sys_props.num_devices-1; ret = kfd_topology_update_sysfs(); up_write(&topology_lock); @@ -1295,8 +1305,6 @@ int kfd_topology_add_device(struct kfd_dev *gpu) pr_debug("Adding new GPU (ID: 0x%x) to topology\n", gpu_id); - proximity_domain = atomic_inc_return(&topology_crat_proximity_domain); - /* Include the CPU in xGMI hive if xGMI connected by assigning it the hive ID. */ if (gpu->hive_id && gpu->adev->gmc.xgmi.connected_to_cpu) { struct kfd_topology_device *top_dev; @@ -1321,12 +1329,16 @@ int kfd_topology_add_device(struct kfd_dev *gpu) */ dev = kfd_assign_gpu(gpu); if (!dev) { + down_write(&topology_lock); + proximity_domain = ++topology_crat_proximity_domain; + res = kfd_create_crat_image_virtual(&crat_image, &image_size, COMPUTE_UNIT_GPU, gpu, proximity_domain); if (res) { pr_err("Error creating VCRAT for GPU (ID: 0x%x)\n", gpu_id); + topology_crat_proximity_domain--; return res; } res = kfd_parse_crat_table(crat_image, @@ -1335,10 +1347,10 @@ int kfd_topology_add_device(struct kfd_dev *gpu) if (res) { pr_err("Error parsing VCRAT for GPU (ID: 0x%x)\n", gpu_id); + topology_crat_proximity_domain--; goto err; } - down_write(&topology_lock); kfd_topology_update_device_list(&temp_topology_device_list, &topology_device_list); @@ -1485,25 +1497,78 @@ err: return res; } +/** + * kfd_topology_update_io_links() - Update IO links after device removal. + * @proximity_domain: Proximity domain value of the dev being removed. + * + * The topology list currently is arranged in increasing order of + * proximity domain. + * + * Two things need to be done when a device is removed: + * 1. All the IO links to this device need to be removed. + * 2. All nodes after the current device node need to move + * up once this device node is removed from the topology + * list. As a result, the proximity domain values for + * all nodes after the node being deleted reduce by 1. + * This would also cause the proximity domain values for + * io links to be updated based on new proximity domain + * values. + * + * Context: The caller must hold write topology_lock. + */ +static void kfd_topology_update_io_links(int proximity_domain) +{ + struct kfd_topology_device *dev; + struct kfd_iolink_properties *iolink, *tmp; + + list_for_each_entry(dev, &topology_device_list, list) { + if (dev->proximity_domain > proximity_domain) + dev->proximity_domain--; + + list_for_each_entry_safe(iolink, tmp, &dev->io_link_props, list) { + /* + * If there is an io link to the dev being deleted + * then remove that IO link also. + */ + if (iolink->node_to == proximity_domain) { + list_del(&iolink->list); + dev->io_link_count--; + dev->node_props.io_links_count--; + } else if (iolink->node_from > proximity_domain) { + iolink->node_from--; + } else if (iolink->node_to > proximity_domain) { + iolink->node_to--; + } + } + + } +} + int kfd_topology_remove_device(struct kfd_dev *gpu) { struct kfd_topology_device *dev, *tmp; uint32_t gpu_id; int res = -ENODEV; + int i = 0; down_write(&topology_lock); - list_for_each_entry_safe(dev, tmp, &topology_device_list, list) + list_for_each_entry_safe(dev, tmp, &topology_device_list, list) { if (dev->gpu == gpu) { gpu_id = dev->gpu_id; kfd_remove_sysfs_node_entry(dev); kfd_release_topology_device(dev); sys_props.num_devices--; + kfd_topology_update_io_links(i); + topology_crat_proximity_domain = sys_props.num_devices-1; + sys_props.generation_count++; res = 0; if (kfd_topology_update_sysfs() < 0) kfd_topology_release_sysfs(); break; } + i++; + } up_write(&topology_lock); -- cgit v1.2.3-59-g8ed1b