x86: Move swiotlb initialization before dma32_free_bootmem

The commit 75f1cdf1 introduced a
bug that we initialize SWIOTLB right after dma32_free_bootmem so
we wrongly steal memory area allocated for GART with broken BIOS
earlier.

This moves swiotlb initialization before dma32_free_bootmem().
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: yinghai@kernel.org
LKML-Reference: <1260759135-6450-2-git-send-email-fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/pci-dma.c

@@ -120,11 +120,14 @@ static void __init dma32_free_bootmem(void)
 
 void __init pci_iommu_alloc(void)
 {
+	int use_swiotlb;
+
+	use_swiotlb = pci_swiotlb_init();
 #ifdef CONFIG_X86_64
 	/* free the range so iommu could get some range less than 4G */
 	dma32_free_bootmem();
 #endif
-	if (pci_swiotlb_init())
+	if (use_swiotlb)
 		return;
 
 	gart_iommu_hole_init();