[PATCH AUTOSEL 5.18 066/159] drm/amdkfd: Fix circular lock dependency warning

Sasha Levin
2022-05-30T13:31:51Z

From: Mukul Joshi <mukul.joshi@amd.com>

[ Upstream commit b179fc28d521379ba7e0a38eec1a4c722e7ea634 ]

[ 168.544078] ======================================================
[ 168.550309] WARNING: possible circular locking dependency detected
[ 168.556523] 5.16.0-kfd-fkuehlin #148 Tainted: G E
[ 168.562558] ------------------------------------------------------
[ 168.568764] kfdtest/3479 is trying to acquire lock:
[ 168.573672] ffffffffc0927a70 (&topology_lock){++++}-{3:3}, at:
kfd_topology_device_by_id+0x16/0x60 [amdgpu] [ 168.583663]
but task is already holding lock:
[ 168.589529] ffff97d303dee668 (&mm->mmap_lock#2){++++}-{3:3}, at:
vm_mmap_pgoff+0xa9/0x180 [ 168.597755]
which lock already depends on the new lock.

[ 168.605970]
the existing dependency chain (in reverse order) is:
[ 168.613487]
-> #3 (&mm->mmap_lock#2){++++}-{3:3}:
[ 168.619700] lock_acquire+0xca/0x2e0
[ 168.623814] down_read+0x3e/0x140
[ 168.627676] do_user_addr_fault+0x40d/0x690
[ 168.632399] exc_page_fault+0x6f/0x270
[ 168.636692] asm_exc_page_fault+0x1e/0x30
[ 168.641249] filldir64+0xc8/0x1e0
[ 168.645115] call_filldir+0x7c/0x110
[ 168.649238] ext4_readdir+0x58e/0x940
[ 168.653442] iterate_dir+0x16a/0x1b0
[ 168.657558] __x64_sys_getdents64+0x83/0x140
[ 168.662375] do_syscall_64+0x35/0x80
[ 168.666492] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 168.672095]
-> #2 (&type->i_mutex_dir_key#6){++++}-{3:3}:
[ 168.679008] lock_acquire+0xca/0x2e0
[ 168.683122] down_read+0x3e/0x140
[ 168.686982] path_openat+0x5b2/0xa50
[ 168.691095] do_file_open_root+0xfc/0x190
[ 168.695652] file_open_root+0xd8/0x1b0
[ 168.702010] kernel_read_file_from_path_initns+0xc4/0x140
[ 168.709542] _request_firmware+0x2e9/0x5e0
[ 168.715741] request_firmware+0x32/0x50
[ 168.721667] amdgpu_cgs_get_firmware_info+0x370/0xdd0 [amdgpu]
[ 168.730060] smu7_upload_smu_firmware_image+0x53/0x190 [amdgpu]
[ 168.738414] fiji_start_smu+0xcf/0x4e0 [amdgpu]
[ 168.745539] pp_dpm_load_fw+0x21/0x30 [amdgpu]
[ 168.752503] amdgpu_pm_load_smu_firmware+0x4b/0x80 [amdgpu]
[ 168.760698] amdgpu_device_fw_loading+0xb8/0x140 [amdgpu]
[ 168.768412] amdgpu_device_init.cold+0xdf6/0x1716 [amdgpu]
[ 168.776285] amdgpu_driver_load_kms+0x15/0x120 [amdgpu]
[ 168.784034] amdgpu_pci_probe+0x19b/0x3a0 [amdgpu]
[ 168.791161] local_pci_probe+0x40/0x80
[ 168.797027] work_for_cpu_fn+0x10/0x20
[ 168.802839] process_one_work+0x273/0x5b0
[ 168.808903] worker_thread+0x20f/0x3d0
[ 168.814700] kthread+0x176/0x1a0
[ 168.819968] ret_from_fork+0x1f/0x30
[ 168.825563]
-> #1 (&adev->pm.mutex){+.+.}-{3:3}:
[ 168.834721] lock_acquire+0xca/0x2e0
[ 168.840364] __mutex_lock+0xa2/0x930
[ 168.846020] amdgpu_dpm_get_mclk+0x37/0x60 [amdgpu]
[ 168.853257] amdgpu_amdkfd_get_local_mem_info+0xba/0xe0 [amdgpu]
[ 168.861547] kfd_create_vcrat_image_gpu+0x1b1/0xbb0 [amdgpu]
[ 168.869478] kfd_create_crat_image_virtual+0x447/0x510 [amdgpu]
[ 168.877884] kfd_topology_add_device+0x5c8/0x6f0 [amdgpu]
[ 168.885556] kgd2kfd_device_init.cold+0x385/0x4c5 [amdgpu]
[ 168.893347] amdgpu_amdkfd_device_init+0x138/0x180 [amdgpu]
[ 168.901177] amdgpu_device_init.cold+0x141b/0x1716 [amdgpu]
[ 168.909025] amdgpu_driver_load_kms+0x15/0x120 [amdgpu]
[ 168.916458] amdgpu_pci_probe+0x19b/0x3a0 [amdgpu]
[ 168.923442] local_pci_probe+0x40/0x80
[ 168.929249] work_for_cpu_fn+0x10/0x20
[ 168.935008] process_one_work+0x273/0x5b0
[ 168.940944] worker_thread+0x20f/0x3d0
[ 168.946623] kthread+0x176/0x1a0
[ 168.951765] ret_from_fork+0x1f/0x30
[ 168.957277]
-> #0 (&topology_lock){++++}-{3:3}:
[ 168.965993] check_prev_add+0x8f/0xbf0
[ 168.971613] __lock_acquire+0x1299/0x1ca0
[ 168.977485] lock_acquire+0xca/0x2e0
[ 168.982877] down_read+0x3e/0x140
[ 168.987975] kfd_topology_device_by_id+0x16/0x60 [amdgpu]
[ 168.995583] kfd_device_by_id+0xa/0x20 [amdgpu]
[ 169.002180] kfd_mmap+0x95/0x200 [amdgpu]
[ 169.008293] mmap_region+0x337/0x5a0
[ 169.013679] do_mmap+0x3aa/0x540
[ 169.018678] vm_mmap_pgoff+0xdc/0x180
[ 169.024095] ksys_mmap_pgoff+0x186/0x1f0
[ 169.029734] do_syscall_64+0x35/0x80
[ 169.035005] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 169.041754]
other info that might help us debug this:

[ 169.053276] Chain exists of:
&topology_lock --> &type->i_mutex_dir_key#6 --> &mm->mmap_lock#2

[ 169.068389] Possible unsafe locking scenario:

[ 169.076661] CPU0 CPU1
[ 169.082383] ---- ----
[ 169.088087] lock(&mm->mmap_lock#2);
[ 169.092922] lock(&type->i_mutex_dir_key#6);
[ 169.100975] lock(&mm->mmap_lock#2);
[ 169.108320] lock(&topology_lock);
[ 169.112957]
*** DEADLOCK ***

This commit fixes the deadlock warning by ensuring pm.mutex is not
held while holding the topology lock. For this, kfd_local_mem_info
is moved into the KFD dev struct and filled during device init.
This cached value can then be used instead of querying the value
again and again.

Signed-off-by: Mukul Joshi <mukul.joshi@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 7 ++-----
drivers/gpu/drm/amd/amdkfd/kfd_crat.c | 2 +-
drivers/gpu/drm/amd/amdkfd/kfd_device.c | 2 ++
drivers/gpu/drm/amd/amdkfd/kfd_priv.h | 1 +
drivers/gpu/drm/amd/amdkfd/kfd_topology.c | 7 ++-----
5 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index 607f65ab39ac..10cc834a5ac3 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -944,8 +944,6 @@ static int kfd_ioctl_acquire_vm(struct file *filep, struct kfd_process *p,

bool kfd_dev_is_large_bar(struct kfd_dev *dev)
{
- struct kfd_local_mem_info mem_info;
-
if (debug_largebar) {
pr_debug("Simulate large-bar allocation on non large-bar machine\n");
return true;
@@ -954,9 +952,8 @@ bool kfd_dev_is_large_bar(struct kfd_dev *dev)
if (dev->use_iommu_v2)
return false;

- amdgpu_amdkfd_get_local_mem_info(dev->adev, &mem_info);
- if (mem_info.local_mem_size_private == 0 &&
- mem_info.local_mem_size_public > 0)
+ if (dev->local_mem_info.local_mem_size_private == 0 &&
+ dev->local_mem_info.local_mem_size_public > 0)
return true;
return false;
}
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
index 1eaabd2cb41b..59b349a4c04a 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
@@ -2152,7 +2152,7 @@ static int kfd_create_vcrat_image_gpu(void *pcrat_image,
* report the total FB size (public+private) as a single
* private heap.
*/
- amdgpu_amdkfd_get_local_mem_info(kdev->adev, &local_mem_info);
+ local_mem_info = kdev->local_mem_info;
sub_type_hdr = (typeof(sub_type_hdr))((char *)sub_type_hdr +
sub_type_hdr->length);

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device.c b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
index 62aa6c9d5123..c96d521447fc 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
@@ -575,6 +575,8 @@ bool kgd2kfd_device_init(struct kfd_dev *kfd,
if (kfd_resume(kfd))
goto kfd_resume_error;

+ amdgpu_amdkfd_get_local_mem_info(kfd->adev, &kfd->local_mem_info);
+
if (kfd_topology_add_device(kfd)) {
dev_err(kfd_device, "Error adding device to topology\n");
goto kfd_topology_add_device_error;
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
index 8f58fc491b28..49a29a60b71e 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
@@ -272,6 +272,7 @@ struct kfd_dev {

struct kgd2kfd_shared_resources shared_resources;
struct kfd_vmid_info vm_info;
+ struct kfd_local_mem_info local_mem_info;

const struct kfd2kgd_calls *kfd2kgd;
struct mutex doorbell_mutex;
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
index 3bdcae239bc0..9fc24f6823df 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
@@ -1102,15 +1102,12 @@ static uint32_t kfd_generate_gpu_id(struct kfd_dev *gpu)
uint32_t buf[7];
uint64_t local_mem_size;
int i;
- struct kfd_local_mem_info local_mem_info;

if (!gpu)
return 0;

- amdgpu_amdkfd_get_local_mem_info(gpu->adev, &local_mem_info);
-
- local_mem_size = local_mem_info.local_mem_size_private +
- local_mem_info.local_mem_size_public;
+ local_mem_size = gpu->local_mem_info.local_mem_size_private +
+ gpu->local_mem_info.local_mem_size_public;

buf[0] = gpu->pdev->devfn;
buf[1] = gpu->pdev->subsystem_vendor |
--
2.35.1