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path: root/drivers/gpu/drm/msm/msm_iommu.c
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Diffstat (limited to 'drivers/gpu/drm/msm/msm_iommu.c')
-rw-r--r--drivers/gpu/drm/msm/msm_iommu.c16
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
index 55c29f49b788..76cdd5ea06a0 100644
--- a/drivers/gpu/drm/msm/msm_iommu.c
+++ b/drivers/gpu/drm/msm/msm_iommu.c
@@ -14,7 +14,9 @@
struct msm_iommu {
struct msm_mmu base;
struct iommu_domain *domain;
- atomic_t pagetables;
+
+ struct mutex init_lock; /* protects pagetables counter and prr_page */
+ int pagetables;
struct page *prr_page;
struct kmem_cache *pt_cache;
@@ -227,7 +229,8 @@ static void msm_iommu_pagetable_destroy(struct msm_mmu *mmu)
* If this is the last attached pagetable for the parent,
* disable TTBR0 in the arm-smmu driver
*/
- if (atomic_dec_return(&iommu->pagetables) == 0) {
+ mutex_lock(&iommu->init_lock);
+ if (--iommu->pagetables == 0) {
adreno_smmu->set_ttbr0_cfg(adreno_smmu->cookie, NULL);
if (adreno_smmu->set_prr_bit) {
@@ -236,6 +239,7 @@ static void msm_iommu_pagetable_destroy(struct msm_mmu *mmu)
iommu->prr_page = NULL;
}
}
+ mutex_unlock(&iommu->init_lock);
free_io_pgtable_ops(pagetable->pgtbl_ops);
kfree(pagetable);
@@ -568,9 +572,12 @@ struct msm_mmu *msm_iommu_pagetable_create(struct msm_mmu *parent, bool kernel_m
* If this is the first pagetable that we've allocated, send it back to
* the arm-smmu driver as a trigger to set up TTBR0
*/
- if (atomic_inc_return(&iommu->pagetables) == 1) {
+ mutex_lock(&iommu->init_lock);
+ if (iommu->pagetables++ == 0) {
ret = adreno_smmu->set_ttbr0_cfg(adreno_smmu->cookie, &ttbr0_cfg);
if (ret) {
+ iommu->pagetables--;
+ mutex_unlock(&iommu->init_lock);
free_io_pgtable_ops(pagetable->pgtbl_ops);
kfree(pagetable);
return ERR_PTR(ret);
@@ -595,6 +602,7 @@ struct msm_mmu *msm_iommu_pagetable_create(struct msm_mmu *parent, bool kernel_m
adreno_smmu->set_prr_bit(adreno_smmu->cookie, true);
}
}
+ mutex_unlock(&iommu->init_lock);
/* Needed later for TLB flush */
pagetable->parent = parent;
@@ -730,7 +738,7 @@ struct msm_mmu *msm_iommu_new(struct device *dev, unsigned long quirks)
iommu->domain = domain;
msm_mmu_init(&iommu->base, dev, &funcs, MSM_MMU_IOMMU);
- atomic_set(&iommu->pagetables, 0);
+ mutex_init(&iommu->init_lock);
ret = iommu_attach_device(iommu->domain, dev);
if (ret) {