From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Date: Tue, 10 Nov 2009 12:35:17 +0000 (+0900)
Subject: x86, 32-bit: Fix swiotlb boot crash
X-Git-Tag: firefly_0821_release~9833^2~3989^2~51
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=72d03802b8b5c841ab1da82bff0652628cbadf60;p=firefly-linux-kernel-4.4.55.git

x86, 32-bit: Fix swiotlb boot crash

Ingo Molnar reported this boot crash:

[    8.655620] pata_amd 0000:00:06.0: version 0.4.1
[    8.660286] BUG: unable to handle kernel NULL pointer dereference at 00000034
[    8.663572] IP: [<c100617b>] dma_supported+0x3b/0xa4
[    8.663572] *pde = 00000000

Initialize dma_ops properly in the 32-bit case.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index a234e63c2656..63eebee80e75 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -129,6 +129,8 @@ void __init pci_iommu_alloc(void)
 #ifdef CONFIG_X86_64
 	/* free the range so iommu could get some range less than 4G */
 	dma32_free_bootmem();
+#else
+	dma_ops = &nommu_dma_ops;
 #endif
 	pci_swiotlb_init();
 	if (use_swiotlb)