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Diffstat (limited to 'Documentation/x86_64/boot-options.txt')
| -rw-r--r-- | Documentation/x86_64/boot-options.txt | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt index f2cd6ef53ff..74b77f9e91b 100644 --- a/Documentation/x86_64/boot-options.txt +++ b/Documentation/x86_64/boot-options.txt @@ -199,12 +199,38 @@ IOMMU allowed overwrite iommu off workarounds for specific chipsets. soft Use software bounce buffering (default for Intel machines) noaperture Don't touch the aperture for AGP. + allowdac Allow DMA >4GB + When off all DMA over >4GB is forced through an IOMMU or bounce + buffering. + nodac Forbid DMA >4GB + panic Always panic when IOMMU overflows swiotlb=pages[,force] pages Prereserve that many 128K pages for the software IO bounce buffering. force Force all IO through the software TLB. + calgary=[64k,128k,256k,512k,1M,2M,4M,8M] + calgary=[translate_empty_slots] + calgary=[disable=<PCI bus number>] + + 64k,...,8M - Set the size of each PCI slot's translation table + when using the Calgary IOMMU. This is the size of the translation + table itself in main memory. The smallest table, 64k, covers an IO + space of 32MB; the largest, 8MB table, can cover an IO space of + 4GB. Normally the kernel will make the right choice by itself. + + translate_empty_slots - Enable translation even on slots that have + no devices attached to them, in case a device will be hotplugged + in the future. + + disable=<PCI bus number> - Disable translation on a given PHB. For + example, the built-in graphics adapter resides on the first bridge + (PCI bus number 0); if translation (isolation) is enabled on this + bridge, X servers that access the hardware directly from user + space might stop working. Use this option if you have devices that + are accessed from userspace directly on some PCI host bridge. + Debugging oops=panic Always panic on oopses. Default is to just kill the process, @@ -217,6 +243,20 @@ Debugging pagefaulttrace Dump all page faults. Only useful for extreme debugging and will create a lot of output. + call_trace=[old|both|newfallback|new] + old: use old inexact backtracer + new: use new exact dwarf2 unwinder + both: print entries from both + newfallback: use new unwinder but fall back to old if it gets + stuck (default) + + call_trace=[old|both|newfallback|new] + old: use old inexact backtracer + new: use new exact dwarf2 unwinder + both: print entries from both + newfallback: use new unwinder but fall back to old if it gets + stuck (default) + Misc noreplacement Don't replace instructions with more appropriate ones |