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]>
---
v2: Use xa_lock_irqsave/__xa_erase/xa_unlock_irqrestore for
amdgpu_pasid_free() instead of xa_erase_irq(), since it can
be called from hardirq context where xa_unlock_irq would
prematurely re-enable interrupts. (Christian König)
v1:
https://lore.kernel.org/all/[email protected]/
drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c | 15 +++++++++++++--
1 file changed, 13 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..6fc6859d9329 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 +84,19 @@ 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);
+
+ /*
+ * Use irqsave because this can be called from IRQ context
+ * via amdgpu_pasid_free_cb. xa_erase_irq() is insufficient
+ * as it uses xa_lock_irq which can prematurely re-enable
+ * interrupts in hardirq context.
+ */
+ 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
