2 files changed, 36 insertions, 0 deletions

diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 73b1f1cec423..59bafa690290 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -88,4 +88,10 @@ swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr);
 extern int
 swiotlb_dma_supported(struct device *hwdev, u64 mask);
 
+#ifdef CONFIG_SWIOTLB
+extern void __init swiotlb_free(void);
+#else
+static inline void swiotlb_free(void) { }
+#endif
+
 #endif /* __LINUX_SWIOTLB_H */
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index ac25cd28e807..eee512b63f17 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -97,6 +97,8 @@ static phys_addr_t *io_tlb_orig_addr;
  */
 static DEFINE_SPINLOCK(io_tlb_lock);
 
+static int late_alloc;
+
 static int __init
 setup_io_tlb_npages(char *str)
 {
@@ -262,6 +264,8 @@ swiotlb_late_init_with_default_size(size_t default_size)
 
         swiotlb_print_info(bytes);
 
+        late_alloc = 1;
+
         return 0;
 
 cleanup4:
@@ -281,6 +285,32 @@ cleanup1:
         return -ENOMEM;
 }
 
+void __init swiotlb_free(void)
+{
+        if (!io_tlb_overflow_buffer)
+                return;
+
+        if (late_alloc) {
+                free_pages((unsigned long)io_tlb_overflow_buffer,
+                           get_order(io_tlb_overflow));
+                free_pages((unsigned long)io_tlb_orig_addr,
+                           get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
+                free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
+                                                                 sizeof(int)));
+                free_pages((unsigned long)io_tlb_start,
+                           get_order(io_tlb_nslabs << IO_TLB_SHIFT));
+        } else {
+                free_bootmem_late(__pa(io_tlb_overflow_buffer),
+                                  io_tlb_overflow);
+                free_bootmem_late(__pa(io_tlb_orig_addr),
+                                  io_tlb_nslabs * sizeof(phys_addr_t));
+                free_bootmem_late(__pa(io_tlb_list),
+                                  io_tlb_nslabs * sizeof(int));
+                free_bootmem_late(__pa(io_tlb_start),
+                                  io_tlb_nslabs << IO_TLB_SHIFT);
+        }
+}
+
 static int is_swiotlb_buffer(phys_addr_t paddr)
 {
         return paddr >= virt_to_phys(io_tlb_start) &&