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drm/amdkfd: Cleanup IO links during KFD device removal

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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 <shuotaoxu@microsoft.com>
Reviewed-by: Shuotao Xu <shuotaoxu@microsoft.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Mukul Joshi <mukul.joshi@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Mukul Joshi 2022-04-06 20:07:37 -04:00 committed by Alex Deucher
parent eb85fc2389
commit 46d18d510d
3 changed files with 78 additions and 11 deletions
drivers/gpu/drm/amd/amdkfd
kfd_crat.ckfd_priv.hkfd_topology.c

4
drivers/gpu/drm/amd/amdkfd/kfd_crat.c
View File

@ -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)

2
drivers/gpu/drm/amd/amdkfd/kfd_priv.h
View File

@ -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);

83
drivers/gpu/drm/amd/amdkfd/kfd_topology.c
View File

@ -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);