4.9.65-rt57-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Sebastian Andrzej Siewior <bige...@linutronix.de>
get_cpu_ptr() disabled preemption and returns the ->flush_queue object
of the current CPU. raw_cpu_ptr() does the same except that it not
disable preemption which means the scheduler can move it to another CPU
after it obtained the per-CPU object.
In this case this is not bad because the data structure itself is
protected with a spin_lock. This change shouldn't matter however on RT
it does because the sleeping lock can't be accessed with disabled
preemption.
Cc: rt-sta...@vger.kernel.org
Cc: Joerg Roedel <j...@8bytes.org>
Cc: iommu@lists.linux-foundation.org
Reported-by: Vinod Adhikary <vina...@gmail.com>
Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
---
drivers/iommu/amd_iommu.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index a88595b21111..ff5c2424eb9e 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -2283,7 +2283,7 @@ static void queue_add(struct dma_ops_domain *dma_dom,
pages = __roundup_pow_of_two(pages);
address >>= PAGE_SHIFT;
- queue = get_cpu_ptr(&flush_queue);
+ queue = raw_cpu_ptr(&flush_queue);
spin_lock_irqsave(&queue->lock, flags);
if (queue->next == FLUSH_QUEUE_SIZE)
@@ -2300,8 +2300,6 @@ static void queue_add(struct dma_ops_domain *dma_dom,
if (atomic_cmpxchg(&queue_timer_on, 0, 1) == 0)
mod_timer(&queue_timer, jiffies + msecs_to_jiffies(10));
-
- put_cpu_ptr(&flush_queue);
}
--
2.13.2
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