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")
Signed-off-by: Mikhail Gavrilov <[email protected]>
---

v3: Shortened comment per Christian König.
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 | 10 ++++++++--
 1 file changed, 8 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..a1f72f5d31d6 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)
@@ -84,8 +84,14 @@ int amdgpu_pasid_alloc(unsigned int bits)
  */
 void amdgpu_pasid_free(u32 pasid)
 {
+       unsigned long flags;
+
        trace_amdgpu_pasid_freed(pasid);
-       xa_erase(&amdgpu_pasid_xa, pasid);
+
+       /* Called from IRQ via amdgpu_pasid_free_cb, needs irqsave */
+       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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