This patch creates a new interface for IOMMUs by adding a centralized
location for IOMMU allocation (for translation tables/apertures) and
IOMMU initialization.  In creating these, code was moved around for
abstraction, uniformity, and consiceness.

Take note of the move of the iommu_setup bootarg parsing code to
__setup.  This is enabled by moving back the location of the aperture
allocation/detection to mem init (which while ugly, was already the
location of the swiotlb_init).

While a slight departure from the previous patch, I belive this provides
the true intention of the previous versions of the patch which changed
this code.  It also makes the addition of the upcoming calgary code much
cleaner than previous patches.

[AK: Removed one broken change. iommu_setup still has to be called
early]
Signed-off-by: NMuli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: NJon Mason <jdmason@us.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

 - Rename the GART_IOMMU option to IOMMU to make clear it's not
   just for AMD
 - Rewrite the help text to better emphatise this fact
 - Make it an embedded option because too many people get it wrong.

To my astonishment I discovered the aacraid driver tests this
symbol directly. This looks quite broken to me - it's an internal
implementation detail of the PCI DMA API. Can the maintainer
please clarify what this test was intended to do?

Cc: linux-scsi@vger.kernel.org
Cc: alan@redhat.com
Cc: markh@osdl.org
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

In previous versions of pci-gart.c, no_iommu was used to determine if IOMMU was
disabled in the GART DMA mapping functions.  This changed in 2.6.16 and now
gart_xxx() functions are only called if gart is enabled.  Therefore, uses of
no_iommu in the GART code are no longer necessary and can be removed.

Also, it removes double deceleration of no_iommu and force_iommu in pci.h and
proto.h, by removing the deceleration in pci.h.

Lastly, end_pfn off by one error.

Tested (along with patch 1/2) on dual opteron with gart enabled, iommu=soft,
and iommu=off.
Signed-off-by: NJon Mason <jdmason@us.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

AK: I hacked Muli's original patch a lot and there were a lot
of changes - all bugs are probably to blame on me now.
There were also some changes in the fall back behaviour
for swiotlb - in particular it doesn't try to use GFP_DMA
now anymore. Also all DMA mapping operations use the
same core dma_alloc_coherent code with proper fallbacks now.
And various other changes and cleanups.

Known problems: iommu=force swiotlb=force together breaks
                needs more testing.

This patch cleans up x86_64's DMA mapping dispatching code. Right now
we have three possible IOMMU types: AGP GART, swiotlb and nommu, and
in the future we will also have Xen's x86_64 swiotlb and other HW
IOMMUs for x86_64. In order to support all of them cleanly, this
patch:

- introduces a struct dma_mapping_ops with function pointers for each
  of the DMA mapping operations of gart (AMD HW IOMMU), swiotlb
  (software IOMMU) and nommu (no IOMMU).

- gets rid of:

  if (swiotlb)
      return swiotlb_xxx();

- PCI_DMA_BUS_IS_PHYS is now checked against the dma_ops being set
This makes swiotlb faster by avoiding double copying in some cases.
Signed-Off-By: NMuli Ben-Yehuda <mulix@mulix.org>
Signed-Off-By: NJon D. Mason <jdmason@us.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Commit id 6142891a

Andi Kleen reports that it seems to break things for some people,
and since it's purely a small optimization, revert it for now.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

PCI_DMA_BUS_IS_PHYS has to be zero even when the GART IOMMU is disabled
and the swiotlb is used. Otherwise the block layer does unnecessary
double bouncing.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This reverts commits

  71db63ac
	[PATCH] increase PCIBIOS_MIN_IO on x86

and

  0b2bfb4e
    ACPI: increase PCIBIOS_MIN_IO on x86

since Lukas Sandströ<lukass@etek.chalmers.se> reports that this breaks
his on-board nvidia audio.

We should re-visit this later. For now we revert the change
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

There is a number of x86 laptops that have some non-PCI IO ports
in the 0x1000-0x1fff range, and it's quite hard to control the correct
order of resource allocation between PCI and other subsystems controlling
these ports. Especially with modular kernel.

So just increase PCIBIOS_MIN_IO to 0x4000 to prevent any new PCI
resource allocations in the problematic range (this limitation must
apply _only_ to the root bus resources - see Linus' change in
pci_bus_alloc_resource).  As PCIBIOS_MIN_IO and PCIBIOS_MIN_CARDBUS_IO
are the same now on i386 and x86-64, we can remove the latter.
Signed-off-by: NIvan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

http://bugme.osdl.org/show_bug.cgi?id=4016Written-by: NDavid Shaohua Li <shaohua.li@intel.com>
Acked-by: NAdam Belay <abelay@novell.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

With CONFIG_PCI=n:

In file included from include/linux/pci.h:917,
                 from lib/iomap.c:6:
include/asm/pci.h:104: warning: `enum pci_dma_burst_strategy' declared inside parameter list
include/asm/pci.h:104: warning: its scope is only this definition or declaration, which is probably not what you want.
include/asm/pci.h: In function `pci_dma_burst_advice':
include/asm/pci.h:106: dereferencing pointer to incomplete type
include/asm/pci.h:106: `PCI_DMA_BURST_INFINITY' undeclared (first use in this function)
include/asm/pci.h:106: (Each undeclared identifier is reported only once
include/asm/pci.h:106: for each function it appears in.)
make[1]: *** [lib/iomap.o] Error 1
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

After seeing, at best, "guesses" as to the following kind
of information in several drivers, I decided that we really
need a way for platforms to specifically give advice in this
area for what works best with their PCI controller implementation.

Basically, this new interface gives DMA bursting advice on
PCI.  There are three forms of the advice:

1) Burst as much as possible, it is not necessary to end bursts
   on some particular boundary for best performance.

2) Burst on some byte count multiple.  A DMA burst to some multiple of
   number of bytes may be done, but it is important to end the burst
   on an exact multiple for best performance.

   The best example of this I am aware of are the PPC64 PCI
   controllers, where if you end a burst mid-cacheline then
   chip has to refetch the data and the IOMMU translations
   which hurts performance a lot.

3) Burst on a single byte count multiple.  Bursts shall end
   exactly on the next multiple boundary for best performance.

   Sparc64 and Alpha's PCI controllers operate this way.  They
   disconnect any device which tries to burst across a cacheline
   boundary.

   Actually, newer sparc64 PCI controllers do not have this behavior.
   That is why the "pdev" is passed into the interface, so I can
   add code later to check which PCI controller the system is using
   and give advice accordingly.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!