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Commit eb4a52bc authored by Fenghua Yu's avatar Fenghua Yu Committed by David Woodhouse
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Intel IOMMU Suspend/Resume Support - Queued Invalidation 



This patch supports queued invalidation suspend/resume.

Signed-off-by: default avatarFenghua Yu <fenghua.yu@intel.com>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent f59c7b69

drivers/pci/dmar.c

+55 −15
Original line number Diff line number Diff line
@@ -789,6 +789,35 @@ void dmar_disable_qi(struct intel_iommu *iommu) 
	spin_unlock_irqrestore(&iommu->register_lock, flags);

}



/*

 * Enable queued invalidation.

 */

static void __dmar_enable_qi(struct intel_iommu *iommu)

{

	u32 cmd, sts;

	unsigned long flags;

	struct q_inval *qi = iommu->qi;



	qi->free_head = qi->free_tail = 0;

	qi->free_cnt = QI_LENGTH;



	spin_lock_irqsave(&iommu->register_lock, flags);



	/* write zero to the tail reg */

	writel(0, iommu->reg + DMAR_IQT_REG);



	dmar_writeq(iommu->reg + DMAR_IQA_REG, virt_to_phys(qi->desc));



	cmd = iommu->gcmd | DMA_GCMD_QIE;

	iommu->gcmd |= DMA_GCMD_QIE;

	writel(cmd, iommu->reg + DMAR_GCMD_REG);



	/* Make sure hardware complete it */

	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG, readl, (sts & DMA_GSTS_QIES), sts);



	spin_unlock_irqrestore(&iommu->register_lock, flags);

}



/*

 * Enable Queued Invalidation interface. This is a must to support

 * interrupt-remapping. Also used by DMA-remapping, which replaces
@@ -796,8 +825,6 @@ void dmar_disable_qi(struct intel_iommu *iommu) 
 */

int dmar_enable_qi(struct intel_iommu *iommu)

{

	u32 cmd, sts;

	unsigned long flags;

	struct q_inval *qi;



	if (!ecap_qis(iommu->ecap))
@@ -835,19 +862,7 @@ int dmar_enable_qi(struct intel_iommu *iommu) 


	spin_lock_init(&qi->q_lock);



	spin_lock_irqsave(&iommu->register_lock, flags);

	/* write zero to the tail reg */

	writel(0, iommu->reg + DMAR_IQT_REG);



	dmar_writeq(iommu->reg + DMAR_IQA_REG, virt_to_phys(qi->desc));



	cmd = iommu->gcmd | DMA_GCMD_QIE;

	iommu->gcmd |= DMA_GCMD_QIE;

	writel(cmd, iommu->reg + DMAR_GCMD_REG);



	/* Make sure hardware complete it */

	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG, readl, (sts & DMA_GSTS_QIES), sts);

	spin_unlock_irqrestore(&iommu->register_lock, flags);

	__dmar_enable_qi(iommu);



	return 0;

}
@@ -1102,3 +1117,28 @@ int __init enable_drhd_fault_handling(void) 


	return 0;

}



/*

 * Re-enable Queued Invalidation interface.

 */

int dmar_reenable_qi(struct intel_iommu *iommu)

{

	if (!ecap_qis(iommu->ecap))

		return -ENOENT;



	if (!iommu->qi)

		return -ENOENT;



	/*

	 * First disable queued invalidation.

	 */

	dmar_disable_qi(iommu);

	/*

	 * Then enable queued invalidation again. Since there is no pending

	 * invalidation requests now, it's safe to re-enable queued

	 * invalidation.

	 */

	__dmar_enable_qi(iommu);



	return 0;

}