Commit f9a4f063 authored by Joerg Roedel's avatar Joerg Roedel
Browse files

iommu/tegra: Don't call alloc_pdir with as->lock 



Instead of taking as->lock before calling alloc_pdir() and
releasing it in that function to allocate memory, just take
the lock only in the alloc_pdir function and run the loop
without any lock held. This simplifies the complicated
lock->unlock->alloc->lock->unlock sequence into
alloc->lock->unlock.

Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent 9e971a03

drivers/iommu/tegra-smmu.c

+16 −13
Original line number Original line Diff line number Diff line
@@ -553,11 +553,11 @@ static inline void put_signature(struct smmu_as *as, 
#endif

#endif





/*

/*

 * Caller must lock/unlock as

 * Caller must not hold as->lock

 */

 */

static int alloc_pdir(struct smmu_as *as, unsigned long *flags)

static int alloc_pdir(struct smmu_as *as)

{

{

	unsigned long *pdir;

	unsigned long *pdir, flags;

	int pdn, err = 0;

	int pdn, err = 0;

	u32 val;

	u32 val;

	struct smmu_device *smmu = as->smmu;

	struct smmu_device *smmu = as->smmu;
@@ -565,13 +565,14 @@ static int alloc_pdir(struct smmu_as *as, unsigned long *flags) 
	unsigned int *cnt;

	unsigned int *cnt;





	/*

	/*

	 * do the allocation outside the as->lock

	 * do the allocation, then grab as->lock

	 */

	 */

	spin_unlock_irqrestore(&as->lock, *flags);

	cnt = devm_kzalloc(smmu->dev,

	cnt = devm_kzalloc(smmu->dev,

			   sizeof(cnt[0]) * SMMU_PDIR_COUNT, GFP_KERNEL);

			   sizeof(cnt[0]) * SMMU_PDIR_COUNT,

			   GFP_KERNEL);

	page = alloc_page(GFP_KERNEL | __GFP_DMA);

	page = alloc_page(GFP_KERNEL | __GFP_DMA);

	spin_lock_irqsave(&as->lock, *flags);



	spin_lock_irqsave(&as->lock, flags);





	if (as->pdir_page) {

	if (as->pdir_page) {

		/* We raced, free the redundant */

		/* We raced, free the redundant */
@@ -603,9 +604,13 @@ static int alloc_pdir(struct smmu_as *as, unsigned long *flags) 
	smmu_write(smmu, val, SMMU_TLB_FLUSH);

	smmu_write(smmu, val, SMMU_TLB_FLUSH);

	FLUSH_SMMU_REGS(as->smmu);

	FLUSH_SMMU_REGS(as->smmu);





	spin_unlock_irqrestore(&as->lock, flags);



	return 0;

	return 0;





err_out:

err_out:

	spin_unlock_irqrestore(&as->lock, flags);



	devm_kfree(smmu->dev, cnt);

	devm_kfree(smmu->dev, cnt);

	if (page)

	if (page)

		__free_page(page);

		__free_page(page);
@@ -809,13 +814,11 @@ static int smmu_iommu_domain_init(struct iommu_domain *domain) 
	/* Look for a free AS with lock held */

	/* Look for a free AS with lock held */

	for  (i = 0; i < smmu->num_as; i++) {

	for  (i = 0; i < smmu->num_as; i++) {

		as = &smmu->as[i];

		as = &smmu->as[i];

		spin_lock_irqsave(&as->lock, flags);

		if (!as->pdir_page) {

		if (!as->pdir_page) {

			err = alloc_pdir(as, &flags);

			err = alloc_pdir(as);

			if (!err)

			if (!err)

				goto found;

				goto found;

		}

		}

		spin_unlock_irqrestore(&as->lock, flags);

		if (err != -EAGAIN)

		if (err != -EAGAIN)

			break;

			break;

	}

	}
@@ -824,7 +827,7 @@ static int smmu_iommu_domain_init(struct iommu_domain *domain) 
	return err;

	return err;





found:

found:

	spin_lock(&smmu->lock);

	spin_lock_irqsave(&smmu->lock, flags);





	/* Update PDIR register */

	/* Update PDIR register */

	smmu_write(smmu, SMMU_PTB_ASID_CUR(as->asid), SMMU_PTB_ASID);

	smmu_write(smmu, SMMU_PTB_ASID_CUR(as->asid), SMMU_PTB_ASID);
@@ -832,12 +835,12 @@ found: 
		   SMMU_MK_PDIR(as->pdir_page, as->pdir_attr), SMMU_PTB_DATA);

		   SMMU_MK_PDIR(as->pdir_page, as->pdir_attr), SMMU_PTB_DATA);

	FLUSH_SMMU_REGS(smmu);

	FLUSH_SMMU_REGS(smmu);





	spin_unlock(&smmu->lock);

	spin_unlock_irqrestore(&smmu->lock, flags);





	spin_unlock_irqrestore(&as->lock, flags);

	domain->priv = as;

	domain->priv = as;





	dev_dbg(smmu->dev, "smmu_as@%p\n", as);

	dev_dbg(smmu->dev, "smmu_as@%p\n", as);



	return 0;

	return 0;

}

}

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