kernel/linux.git/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.h, branch v6.1.168

drm/amdgpu: Replace Mutex with Spinlock for RLCG register access to avoid Priority Inversion in SRIOV

2026-02-06T15:44:24+00:00

[ Upstream commit dc0297f3198bd60108ccbd167ee5d9fa4af31ed0 ] RLCG Register Access is a way for virtual functions to safely access GPU registers in a virtualized environment., including TLB flushes and register reads. When multiple threads or VFs try to access the same registers simultaneously, it can lead to race conditions. By using the RLCG interface, the driver can serialize access to the registers. This means that only one thread can access the registers at a time, preventing conflicts and ensuring that operations are performed correctly. Additionally, when a low-priority task holds a mutex that a high-priority task needs, ie., If a thread holding a spinlock tries to acquire a mutex, it can lead to priority inversion. register access in amdgpu_virt_rlcg_reg_rw especially in a fast code path is critical. The call stack shows that the function amdgpu_virt_rlcg_reg_rw is being called, which attempts to acquire the mutex. This function is invoked from amdgpu_sriov_wreg, which in turn is called from gmc_v11_0_flush_gpu_tlb. The [ BUG: Invalid wait context ] indicates that a thread is trying to acquire a mutex while it is in a context that does not allow it to sleep (like holding a spinlock). Fixes the below: [ 253.013423] ============================= [ 253.013434] [ BUG: Invalid wait context ] [ 253.013446] 6.12.0-amdstaging-drm-next-lol-050225 #14 Tainted: G U OE [ 253.013464] ----------------------------- [ 253.013475] kworker/0:1/10 is trying to lock: [ 253.013487] ffff9f30542e3cf8 (&adev->virt.rlcg_reg_lock){+.+.}-{3:3}, at: amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu] [ 253.013815] other info that might help us debug this: [ 253.013827] context-{4:4} [ 253.013835] 3 locks held by kworker/0:1/10: [ 253.013847] #0: ffff9f3040050f58 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x3f5/0x680 [ 253.013877] #1: ffffb789c008be40 ((work_completion)(&wfc.work)){+.+.}-{0:0}, at: process_one_work+0x1d6/0x680 [ 253.013905] #2: ffff9f3054281838 (&adev->gmc.invalidate_lock){+.+.}-{2:2}, at: gmc_v11_0_flush_gpu_tlb+0x198/0x4f0 [amdgpu] [ 253.014154] stack backtrace: [ 253.014164] CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Tainted: G U OE 6.12.0-amdstaging-drm-next-lol-050225 #14 [ 253.014189] Tainted: [U]=USER, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE [ 253.014203] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 11/18/2024 [ 253.014224] Workqueue: events work_for_cpu_fn [ 253.014241] Call Trace: [ 253.014250] [ 253.014260] dump_stack_lvl+0x9b/0xf0 [ 253.014275] dump_stack+0x10/0x20 [ 253.014287] __lock_acquire+0xa47/0x2810 [ 253.014303] ? srso_alias_return_thunk+0x5/0xfbef5 [ 253.014321] lock_acquire+0xd1/0x300 [ 253.014333] ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu] [ 253.014562] ? __lock_acquire+0xa6b/0x2810 [ 253.014578] __mutex_lock+0x85/0xe20 [ 253.014591] ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu] [ 253.014782] ? sched_clock_noinstr+0x9/0x10 [ 253.014795] ? srso_alias_return_thunk+0x5/0xfbef5 [ 253.014808] ? local_clock_noinstr+0xe/0xc0 [ 253.014822] ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu] [ 253.015012] ? srso_alias_return_thunk+0x5/0xfbef5 [ 253.015029] mutex_lock_nested+0x1b/0x30 [ 253.015044] ? mutex_lock_nested+0x1b/0x30 [ 253.015057] amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu] [ 253.015249] amdgpu_sriov_wreg+0xc5/0xd0 [amdgpu] [ 253.015435] gmc_v11_0_flush_gpu_tlb+0x44b/0x4f0 [amdgpu] [ 253.015667] gfx_v11_0_hw_init+0x499/0x29c0 [amdgpu] [ 253.015901] ? __pfx_smu_v13_0_update_pcie_parameters+0x10/0x10 [amdgpu] [ 253.016159] ? srso_alias_return_thunk+0x5/0xfbef5 [ 253.016173] ? smu_hw_init+0x18d/0x300 [amdgpu] [ 253.016403] amdgpu_device_init+0x29ad/0x36a0 [amdgpu] [ 253.016614] amdgpu_driver_load_kms+0x1a/0xc0 [amdgpu] [ 253.017057] amdgpu_pci_probe+0x1c2/0x660 [amdgpu] [ 253.017493] local_pci_probe+0x4b/0xb0 [ 253.017746] work_for_cpu_fn+0x1a/0x30 [ 253.017995] process_one_work+0x21e/0x680 [ 253.018248] worker_thread+0x190/0x330 [ 253.018500] ? __pfx_worker_thread+0x10/0x10 [ 253.018746] kthread+0xe7/0x120 [ 253.018988] ? __pfx_kthread+0x10/0x10 [ 253.019231] ret_from_fork+0x3c/0x60 [ 253.019468] ? __pfx_kthread+0x10/0x10 [ 253.019701] ret_from_fork_asm+0x1a/0x30 [ 253.019939] v2: s/spin_trylock/spin_lock_irqsave to be safe (Christian). Fixes: e864180ee49b ("drm/amdgpu: Add lock around VF RLCG interface") Cc: lin cao Cc: Jingwen Chen Cc: Victor Skvortsov Cc: Zhigang Luo Cc: Christian König Cc: Alex Deucher Signed-off-by: Srinivasan Shanmugam Suggested-by: Alex Deucher Reviewed-by: Christian König Signed-off-by: Alex Deucher [ Minor conflict resolved. ] Signed-off-by: Li hongliang <1468888505@139.com> Signed-off-by: Greg Kroah-Hartman

drm/amdgpu: trigger flr_work if reading pf2vf data failed

2025-05-22T12:10:00+00:00

[ Upstream commit ab66c832847fcdffc97d4591ba5547e3990d9d33 ] if reading pf2vf data failed 30 times continuously, it means something is wrong. Need to trigger flr_work to recover the issue. also use dev_err to print the error message to get which device has issue and add warning message if waiting IDH_FLR_NOTIFICATION_CMPL timeout. Signed-off-by: Zhigang Luo Acked-by: Hawking Zhang Signed-off-by: Alex Deucher Stable-dep-of: d0ce1aaa8531 ("Revert "drm/amd: Stop evicting resources on APUs in suspend"") Signed-off-by: Sasha Levin

drm/amdgpu: Add lock around VF RLCG interface

2024-08-14T11:52:48+00:00

[ Upstream commit e864180ee49b4d30e640fd1e1d852b86411420c9 ] flush_gpu_tlb may be called from another thread while device_gpu_recover is running. Both of these threads access registers through the VF RLCG interface during VF Full Access. Add a lock around this interface to prevent race conditions between these threads. Signed-off-by: Victor Skvortsov Reviewed-by: Zhigang Luo Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amdgpu: Fix type of second parameter in trans_msg() callback

2022-12-31T12:33:01+00:00

[ Upstream commit f0d0f1087333714ee683cc134a95afe331d7ddd9 ] With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG), indirect call targets are validated against the expected function pointer prototype to make sure the call target is valid to help mitigate ROP attacks. If they are not identical, there is a failure at run time, which manifests as either a kernel panic or thread getting killed. A proposed warning in clang aims to catch these at compile time, which reveals: drivers/gpu/drm/amd/amdgpu/mxgpu_ai.c:412:15: error: incompatible function pointer types initializing 'void (*)(struct amdgpu_device *, u32, u32, u32, u32)' (aka 'void (*)(struct amdgpu_device *, unsigned int, unsigned int, unsigned int, unsigned int)') with an expression of type 'void (struct amdgpu_device *, enum idh_request, u32, u32, u32)' (aka 'void (struct amdgpu_device *, enum idh_request, unsigned int, unsigned int, unsigned int)') [-Werror,-Wincompatible-function-pointer-types-strict] .trans_msg = xgpu_ai_mailbox_trans_msg, ^~~~~~~~~~~~~~~~~~~~~~~~~ 1 error generated. drivers/gpu/drm/amd/amdgpu/mxgpu_nv.c:435:15: error: incompatible function pointer types initializing 'void (*)(struct amdgpu_device *, u32, u32, u32, u32)' (aka 'void (*)(struct amdgpu_device *, unsigned int, unsigned int, unsigned int, unsigned int)') with an expression of type 'void (struct amdgpu_device *, enum idh_request, u32, u32, u32)' (aka 'void (struct amdgpu_device *, enum idh_request, unsigned int, unsigned int, unsigned int)') [-Werror,-Wincompatible-function-pointer-types-strict] .trans_msg = xgpu_nv_mailbox_trans_msg, ^~~~~~~~~~~~~~~~~~~~~~~~~ 1 error generated. The type of the second parameter in the prototype should be 'enum idh_request' instead of 'u32'. Update it to clear up the warnings. Link: https://github.com/ClangBuiltLinux/linux/issues/1750 Reported-by: Sami Tolvanen Reviewed-by: Kees Cook Signed-off-by: Nathan Chancellor Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin

drm/amdgpu: set vm_update_mode=0 as default for Sienna Cichlid in SRIOV case

2022-10-19T02:07:58+00:00

For asic with VF MMIO access protection avoid using CPU for VM table updates. CPU pagetable updates have issues with HDP flush as VF MMIO access protection blocks write to mmBIF_BX_DEV0_EPF0_VF0_HDP_MEM_COHERENCY_FLUSH_CNTL register during sriov runtime. v3: introduce virtualization capability flag AMDGPU_VF_MMIO_ACCESS_PROTECT which indicates that VF MMIO write access is not allowed in sriov runtime Signed-off-by: Danijel Slivka Reviewed-by: Felix Kuehling Signed-off-by: Alex Deucher

drm/amdgpu: Support PSP 13.0.10 on SR-IOV

2022-09-01T19:11:26+00:00

Add support for PSP 13.0.10 for SR-IOV VF Acked-by: Christian König Signed-off-by: Horace Chen Reviewed-by: Hawking Zhang Signed-off-by: Alex Deucher

drm/amdgpu: refine virtualization psp fw skip check

2022-09-01T19:11:12+00:00

SR-IOV may need to load different firmwares for different ASIC inside VF. So create a new function in amdgpu_virt to check whether FW load needs to be skipped. Acked-by: Christian König Signed-off-by: Horace Chen Reviewed-by: Hawking Zhang Signed-off-by: Alex Deucher

drm/amdgpu: Fix wait for RLCG command completion

2022-02-16T22:30:02+00:00

if (!(tmp & flag)) condition will always evaluate to true when the flag is 0x0 (AMDGPU_RLCG_GC_WRITE). Instead check that address bits are cleared to determine whether the command is complete. Signed-off-by: Victor Skvortsov Tested-by: Bokun Zhang Reviewed by: Shaoyun.liu Signed-off-by: Alex Deucher

drm/amdgpu: add determine passthrough under arm64

2022-01-27T20:47:34+00:00

add determine for passthrough mode under arm64 by reading CurrentEL register v2: squash in warning fix (Alex) Signed-off-by: Victor Zhao Acked-by: Alex Deucher Signed-off-by: Alex Deucher

drm/amdgpu: retire rlc callbacks sriov_rreg/wreg

2022-01-25T23:00:33+00:00

Not needed anymore. Signed-off-by: Hawking Zhang Reviewed-by: Zhou, Peng Ju Acked-by: Christian König Reviewed-by: Lijo Lazar Signed-off-by: Alex Deucher