On Wed, Apr 1, 2026 at 7:39 AM Mikhail Gavrilov
<[email protected]> wrote:
>
> xa_alloc_cyclic() and xa_erase() use plain xa_lock()/xa_unlock()
> regardless of XA_FLAGS_LOCK_IRQ — the flag only affects lockdep
> annotations, not runtime locking.
>
> Switch amdgpu_pasid_alloc() to xa_alloc_cyclic_irq() which uses
> xa_lock_irq/xa_unlock_irq internally.
>
> For amdgpu_pasid_free(), use explicit xa_lock_irqsave/__xa_erase/
> xa_unlock_irqrestore since this function can be called from hardirq
> context via amdgpu_pasid_free_cb, where xa_erase_irq()'s
> xa_lock_irq/xa_unlock_irq would prematurely re-enable interrupts.
>
> Fixes: a3c0ee978e16 ("drm/amdgpu: replace PASID IDR with XArray")
> Reviewed-by: Christian König <[email protected]>
> Signed-off-by: Mikhail Gavrilov <[email protected]>

Applied and squashed into the original patch.

Thanks!

Alex

> ---
>
> v4: Move comment to kerneldoc, add Reviewed-by. (Christian König)
> v3: Shortened comment per Christian König.
>     
> https://lore.kernel.org/all/[email protected]/
> v2: Use xa_lock_irqsave/__xa_erase/xa_unlock_irqrestore for
>     amdgpu_pasid_free() instead of xa_erase_irq(). (Christian König)
>     
> https://lore.kernel.org/all/[email protected]/
> v1: 
> https://lore.kernel.org/all/[email protected]/
>
>  drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c 
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c
> index a6ac3b4ce0df..684f40fce73f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c
> @@ -68,7 +68,7 @@ int amdgpu_pasid_alloc(unsigned int bits)
>         if (bits == 0)
>                 return -EINVAL;
>
> -       r = xa_alloc_cyclic(&amdgpu_pasid_xa, &pasid, xa_mk_value(0),
> +       r = xa_alloc_cyclic_irq(&amdgpu_pasid_xa, &pasid, xa_mk_value(0),
>                             XA_LIMIT(1, (1U << bits) - 1),
>                             &amdgpu_pasid_xa_next, GFP_KERNEL);
>         if (r < 0)
> @@ -81,11 +81,18 @@ int amdgpu_pasid_alloc(unsigned int bits)
>  /**
>   * amdgpu_pasid_free - Free a PASID
>   * @pasid: PASID to free
> + *
> + * Called in IRQ context.
>   */
>  void amdgpu_pasid_free(u32 pasid)
>  {
> +       unsigned long flags;
> +
>         trace_amdgpu_pasid_freed(pasid);
> -       xa_erase(&amdgpu_pasid_xa, pasid);
> +
> +       xa_lock_irqsave(&amdgpu_pasid_xa, flags);
> +       __xa_erase(&amdgpu_pasid_xa, pasid);
> +       xa_unlock_irqrestore(&amdgpu_pasid_xa, flags);
>  }
>
>  static void amdgpu_pasid_free_cb(struct dma_fence *fence,
> --
> 2.53.0
>

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