[COMMON] iommu/exynos: alloc page table entry with gfp mask

Page table entry can be allocated with GFP_KERNEL if mapping request is
passed by iommu_map(), because it is outside of spinlock boundary.

Change-Id: I59fc5666597ee41f060bccfe91772c603acf9a12
Signed-off-by: Janghyuck Kim <janghyuck.kim@samsung.com>

diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index 230d2a9630cd48453a075a9e453fbb1ece21c853..7a20cc63ad5b97978e1b2cf37c37cb25b07995e6 100644 (file)
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -1212,7 +1212,8 @@ static void exynos_iommu_detach_device(struct iommu_domain *iommu_domain,
 }
 
 static sysmmu_pte_t *alloc_lv2entry(struct exynos_iommu_domain *domain,
-               sysmmu_pte_t *sent, sysmmu_iova_t iova, atomic_t *pgcounter)
+                               sysmmu_pte_t *sent, sysmmu_iova_t iova,
+                               atomic_t *pgcounter, gfp_t gfpmask)
 {
        if (lv1ent_section(sent)) {
                WARN(1, "Trying mapping on %#08x mapped with 1MiB page", iova);
@@ -1221,15 +1222,22 @@ static sysmmu_pte_t *alloc_lv2entry(struct exynos_iommu_domain *domain,
 
        if (lv1ent_fault(sent)) {
                unsigned long flags;
+               sysmmu_pte_t *pent = NULL;
+
+               if (!(gfpmask & __GFP_ATOMIC)) {
+                       pent = kmem_cache_zalloc(lv2table_kmem_cache, gfpmask);
+                       if (!pent)
+                               return ERR_PTR(-ENOMEM);
+               }
+
                spin_lock_irqsave(&domain->pgtablelock, flags);
                if (lv1ent_fault(sent)) {
-                       sysmmu_pte_t *pent;
-
-                       pent = kmem_cache_zalloc(lv2table_kmem_cache, GFP_ATOMIC);
-                       BUG_ON((unsigned long)pent & (LV2TABLE_SIZE - 1));
                        if (!pent) {
-                               spin_unlock_irqrestore(&domain->pgtablelock, flags);
-                               return ERR_PTR(-ENOMEM);
+                               pent = kmem_cache_zalloc(lv2table_kmem_cache, gfpmask);
+                               if (!pent) {
+                                       spin_unlock_irqrestore(&domain->pgtablelock, flags);
+                                       return ERR_PTR(-ENOMEM);
+                               }
                        }
 
                        *sent = mk_lv1ent_page(virt_to_phys(pent));
@@ -1237,6 +1245,9 @@ static sysmmu_pte_t *alloc_lv2entry(struct exynos_iommu_domain *domain,
                        atomic_set(pgcounter, NUM_LV2ENTRIES);
                        pgtable_flush(pent, pent + NUM_LV2ENTRIES);
                        pgtable_flush(sent, sent + 1);
+               } else {
+                       /* Pre-allocated entry is not used, so free it. */
+                       kmem_cache_free(lv2table_kmem_cache, pent);
                }
                spin_unlock_irqrestore(&domain->pgtablelock, flags);
        }
@@ -1331,7 +1342,7 @@ static int exynos_iommu_map(struct iommu_domain *iommu_domain,
                sysmmu_pte_t *pent;
 
                pent = alloc_lv2entry(domain, entry, iova,
-                                     &domain->lv2entcnt[lv1ent_offset(iova)]);
+                             &domain->lv2entcnt[lv1ent_offset(iova)], GFP_KERNEL);
 
                if (IS_ERR(pent))
                        ret = PTR_ERR(pent);
@@ -1775,7 +1786,7 @@ static sysmmu_pte_t *alloc_lv2entry_userptr(struct exynos_iommu_domain *domain,
                                                sysmmu_iova_t iova)
 {
        return alloc_lv2entry(domain, section_entry(domain->pgtable, iova),
-                               iova, &domain->lv2entcnt[lv1ent_offset(iova)]);
+                       iova, &domain->lv2entcnt[lv1ent_offset(iova)], GFP_ATOMIC);
 }
 
 static int sysmmu_map_pte(struct mm_struct *mm,