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Commit c4596114 authored by Joerg Roedel's avatar Joerg Roedel
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x86/amd-iommu: Add per IOMMU reference counting 



This patch adds reference counting for protection domains
per IOMMU. This allows a smarter TLB flushing strategy.

Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent bb52777e

arch/x86/include/asm/amd_iommu_types.h

+2 −0
Original line number Diff line number Diff line
@@ -238,7 +238,9 @@ struct protection_domain { 
	unsigned long flags;	/* flags to find out type of domain */

	bool updated;		/* complete domain flush required */

	unsigned dev_cnt;	/* devices assigned to this domain */

	unsigned dev_iommu[MAX_IOMMUS]; /* per-IOMMU reference count */

	void *priv;		/* private data */



};



/*

arch/x86/kernel/amd_iommu.c

+9 −3
Original line number Diff line number Diff line
@@ -1175,6 +1175,8 @@ static void __attach_device(struct amd_iommu *iommu, 
	/* update DTE entry */

	set_dte_entry(devid, domain);



	/* Do reference counting */

	domain->dev_iommu[iommu->index] += 1;

	domain->dev_cnt                 += 1;



	/* ready */
@@ -1209,6 +1211,9 @@ static void attach_device(struct amd_iommu *iommu, 
 */

static void __detach_device(struct protection_domain *domain, u16 devid)

{

	struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];



	BUG_ON(!iommu);



	/* lock domain */

	spin_lock(&domain->lock);
@@ -1223,7 +1228,8 @@ static void __detach_device(struct protection_domain *domain, u16 devid) 


	amd_iommu_apply_erratum_63(devid);



	/* decrease reference counter */

	/* decrease reference counters */

	domain->dev_iommu[iommu->index] -= 1;

	domain->dev_cnt                 -= 1;



	/* ready */