swiotlb: Add swiotlb_free() function

swiotlb_free() function frees all allocated memory for swiotlb.

We need to initialize swiotlb before IOMMU initialization (x86
and powerpc needs to allocate memory from bootmem allocator). If
IOMMU initialization is successful, we need to free swiotlb
resource (don't want to waste 64MB).

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: chrisw@sous-sol.org
Cc: dwmw2@infradead.org
Cc: joerg.roedel@amd.com
Cc: muli@il.ibm.com
LKML-Reference: <1257849980-22640-8-git-send-email-fujita.tomonori@lab.ntt.co.jp>
[ -v2: build fix for the !CONFIG_SWIOTLB case ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 6 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 */