1. 20 11月, 2009 1 次提交
    • D
      Fix handling of the HP/Acer 'DMAR at zero' BIOS error for machines with <4GiB RAM. · 5854d9c8
      David Woodhouse 提交于
      Commit 86cf898e ("intel-iommu: Check for
      'DMAR at zero' BIOS error earlier.") was supposed to work by pretending
      not to detect an IOMMU if it was actually being reported by the BIOS at
      physical address zero.
      
      However, the intel_iommu_init() function is called unconditionally, as
      are the corresponding functions for other IOMMU hardware.
      
      So the patch only worked if you have RAM above the 4GiB boundary. It
      caused swiotlb to be initialised when no IOMMU was detected during early
      boot, and thus the later IOMMU init would refuse to run.
      
      But if you have less RAM than that, swiotlb wouldn't get set up and the
      IOMMU _would_ still end up being initialised, even though we never
      claimed to detect it.
      
      This patch also sets the dmar_disabled flag when the error is detected
      during the initial detection phase -- so that the later call to
      intel_iommu_init() will return without doing anything, regardless of
      whether swiotlb is used or not.
      Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5854d9c8
  2. 19 11月, 2009 11 次提交
  3. 18 11月, 2009 28 次提交