On 4/1/26 09:36, Mikhail Gavrilov 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 to xa_alloc_cyclic_irq() and xa_erase_irq() which use
> xa_lock_irq/xa_unlock_irq internally, fixing the IRQ safety issue
> for amdgpu_pasid_free() called from hardirq via fence callbacks.
>
> Fixes: a3c0ee978e16 ("drm/amdgpu: replace PASID IDR with XArray")
> Signed-off-by: Mikhail Gavrilov <[email protected]>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c | 4 ++--
> 1 file changed, 2 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..64d0da28441f 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)
> @@ -85,7 +85,7 @@ int amdgpu_pasid_alloc(unsigned int bits)
> void amdgpu_pasid_free(u32 pasid)
> {
> trace_amdgpu_pasid_freed(pasid);
> - xa_erase(&amdgpu_pasid_xa, pasid);
> + xa_erase_irq(&amdgpu_pasid_xa, pasid);
This one needs to use:
xa_lock_irqsave(xa, flags);
__xa_eras(...);
xa_unlock_irqrestore(xa, flags);
Since it is actually used in IRQ context and not process context.
Apart from that looks good to me.
Regards,
Christian.
> }
>
> static void amdgpu_pasid_free_cb(struct dma_fence *fence,
