Merge branch 'stable/for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb

Pull swiotlb fixes from Konrad Rzeszutek Wilk:
 "This has one fix to make i915 work when using Xen SWIOTLB, and a
  feature from Geert to aid in debugging of devices that can't do DMA
  outside the 32-bit address space.

  The feature from Geert is on top of v4.10 merge window commit
  (specifically you pulling my previous branch), as his changes were
  dependent on the Documentation/ movement patches.

  I figured it would just easier than me trying than to cherry-pick the
  Documentation patches to satisfy git.

  The patches have been soaking since 12/20, albeit I updated the last
  patch due to linux-next catching an compiler error and adding an
  Tested-and-Reported-by tag"

* 'stable/for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
  swiotlb: Export swiotlb_max_segment to users
  swiotlb: Add swiotlb=noforce debug option
  swiotlb: Convert swiotlb_force from int to enum
  x86, swiotlb: Simplify pci_swiotlb_detect_override()

Documentation/admin-guide/kernel-parameters.txt

@@ -3821,10 +3821,11 @@
 			it if 0 is given (See Documentation/cgroup-v1/memory.txt)
 
 	swiotlb=	[ARM,IA-64,PPC,MIPS,X86]
-			Format: { <int> | force }
+			Format: { <int> | force | noforce }
 			<int> -- Number of I/O TLB slabs
 			force -- force using of bounce buffers even if they
 			         wouldn't be automatically used by the kernel
+			noforce -- Never use bounce buffers (for debugging)
 
 	switches=	[HW,M68k]