android/android_kernel_asus_sm8350
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

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

Browse Source 
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: Joerg Roedel <joerg.roedel@amd.com>
This commit is contained in:
Joerg Roedel
2012-07-17 11:47:14 +02:00
parent 9e971a03af
commit f9a4f063a8
1 changed files with 16 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
drivers/iommu/tegra-smmu.c
View File

@ -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;
} }