4.9.65-rt57-rc2 stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> 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: stable-rt@xxxxxxxxxxxxxxx Cc: Joerg Roedel <joro@xxxxxxxxxx> Cc: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx Reported-by: Vinod Adhikary <vinadhy@xxxxxxxxx> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> --- 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 -- To unsubscribe from this list: send the line "unsubscribe stable-rt" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
