Intel IOMMU: Avoid memory allocation failures in dma map api calls

[karo-tx-linux.git] / drivers / pci / intel-iommu.c

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 93ed771b3254b52a18127bf1cf58f964bbf1e50a..05630b44dbfc9b280ec5c3e5551849f6c784fae0 100644 (file)
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -85,9 +85,31 @@ static struct kmem_cache *iommu_domain_cache;
 static struct kmem_cache *iommu_devinfo_cache;
 static struct kmem_cache *iommu_iova_cache;
 
+static inline void *iommu_kmem_cache_alloc(struct kmem_cache *cachep)
+{
+       unsigned int flags;
+       void *vaddr;
+
+       /* trying to avoid low memory issues */
+       flags = current->flags & PF_MEMALLOC;
+       current->flags |= PF_MEMALLOC;
+       vaddr = kmem_cache_alloc(cachep, GFP_ATOMIC);
+       current->flags &= (~PF_MEMALLOC | flags);
+       return vaddr;
+}
+
+
 static inline void *alloc_pgtable_page(void)
 {
-       return (void *)get_zeroed_page(GFP_ATOMIC);
+       unsigned int flags;
+       void *vaddr;
+
+       /* trying to avoid low memory issues */
+       flags = current->flags & PF_MEMALLOC;
+       current->flags |= PF_MEMALLOC;
+       vaddr = (void *)get_zeroed_page(GFP_ATOMIC);
+       current->flags &= (~PF_MEMALLOC | flags);
+       return vaddr;
 }
 
 static inline void free_pgtable_page(void *vaddr)
@@ -97,7 +119,7 @@ static inline void free_pgtable_page(void *vaddr)
 
 static inline void *alloc_domain_mem(void)
 {
-       return kmem_cache_alloc(iommu_domain_cache, GFP_ATOMIC);
+       return iommu_kmem_cache_alloc(iommu_domain_cache);
 }
 
 static inline void free_domain_mem(void *vaddr)
@@ -107,7 +129,7 @@ static inline void free_domain_mem(void *vaddr)
 
 static inline void * alloc_devinfo_mem(void)
 {
-       return kmem_cache_alloc(iommu_devinfo_cache, GFP_ATOMIC);
+       return iommu_kmem_cache_alloc(iommu_devinfo_cache);
 }
 
 static inline void free_devinfo_mem(void *vaddr)
@@ -117,7 +139,7 @@ static inline void free_devinfo_mem(void *vaddr)
 
 struct iova *alloc_iova_mem(void)
 {
-       return kmem_cache_alloc(iommu_iova_cache, GFP_ATOMIC);
+       return iommu_kmem_cache_alloc(iommu_iova_cache);
 }
 
 void free_iova_mem(struct iova *iova)