tree 834419e2fffecbba9f1d5cf6acb3a8765206e438
parent 4cf2e75d0bec15d945972b005056c4a8731b82cf
author Zhao, Yu <yu.zhao@intel.com> 1234518949 +0800
committer David Woodhouse <David.Woodhouse@intel.com> 1237997029 +0000

intel-iommu: Fix address wrap on 32-bit kernel.

The problem is in dma_pte_clear_range and dma_pte_free_pagetable. When
intel_unmap_single and intel_unmap_sg call them, the end address may be
zero if the 'start_addr + size' rounds up. So no PTE gets cleared. The
uncleared PTE fires the BUG_ON when it's used again to create new mappings.

After I modified dma_pte_clear_range a bit, the BUG_ON is gone.

Tested both 32 and 32 PAE modes on Intel X58 and Q35 platforms.

Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>