kbuild spits outs following warning on a
defconfig x86_64 build:
WARNING: swiotlb.o - Section mismatch: reference to .init.text:swiotlb_init from __ksymtab between '__ksymtab_swiotlb_init' (at offset 0xa0) and '__ksymtab_swiotlb_free_coherent'

This warning happens because the function swiotlb_init is marked __init and
EXPORT_SYMBOL().  A 'git grep swiotlb_init' showed no users in drivers/ so
remove the EXPORT_SYMBOL.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit 51099005.

Optimise swiotlb.c for size.

   text    data     bss     dec     hex filename
   5009      89      64    5162    142a lib/swiotlb.o-before
   4666      89      64    4819    12d3 lib/swiotlb.o-after

For some reason my gcc (4.0.2) doesn't want to tailcall these things.

swiotlb_sync_sg_for_device:
	pushq	%rbp	#
	movl	$1, %r8d	#,
	movq	%rsp, %rbp	#,
	call	swiotlb_sync_sg	#
	leave
	ret
	.size	swiotlb_sync_sg_for_device, .-swiotlb_sync_sg_for_device
	.section	.text.swiotlb_sync_sg_for_cpu,"ax",@progbits
.globl swiotlb_sync_sg_for_cpu
	.type	swiotlb_sync_sg_for_cpu, @function
swiotlb_sync_sg_for_cpu:
	pushq	%rbp	#
	xorl	%r8d, %r8d	#
	movq	%rsp, %rbp	#,
	call	swiotlb_sync_sg	#
	leave
	ret

Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add abstraction so that the file can be used by environments other than IA64
and EM64T, namely for Xen.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

- add proper __init decoration to swiotlb's init code (and the code calling
  it, where not already the case)

- replace uses of 'unsigned long' with dma_addr_t where appropriate

- do miscellaneous simplicfication and cleanup
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Convert all phys_to_virt/virt_to_phys uses to bus_to_virt/virt_to_bus, as is
what is meant and what is needed in (at least) some virtualized environments
like Xen.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Acked-by: NMuli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

This patch fixes
- marking I-cache clean of pages DMAed to now only done for IA64
- broken multiple inclusion in include/asm-x86_64/swiotlb.h
- missing call to mark_clean in swiotlb_sync_sg()
- a (perhaps only theoretical) issue in swiotlb_dma_supported() when
io_tlb_end is exactly at the end of memory
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.
Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

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>

Patch cleans up the alloc_bootmem fix for swiotlb.  Patch removes
alloc_bootmem_*_limit api and fixes alloc_boot_*low api to do the right
thing -- allocate from low32 memory.
Signed-off-by: NRavikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The overflow checking condition in lib/swiotlb.c was wrong.
It would first run a NULL pointer through virt_to_phys before
testing it. Since pci_map_sg overflow is not that uncommon
and causes data corruption (including broken file systems) when not
properly detected I think it's better to fix it in 2.6.15.

This affects x86-64 and IA64.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Matthew Wilcox pointed out that swiotlb.c implements a generic
interface that is not tied to just PCI.  Remove includes of
<linux/pci.h>, <asm/pci.h>.  Fix comments and printk() messages
to no longer refer to PCI.
Signed-off-by: NTony Luck <tony.luck@intel.com>

Change comment at top of swiotlb.c to reflect that the code is shared
with EM64T (i.e. Intel x86_64). Also add an entry for myself so that
if I "broke it", everyone knows who "bought it"... :-)
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

The current implementation of sync_single in swiotlb.c chokes on
DMA_BIDIRECTIONAL mappings. This patch adds the capability to sync
those mappings, and optimizes other syncs by accounting for the
sync target (i.e. cpu or device) in addition to the DMA direction of
the mapping.
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

This patch implements swiotlb_sync_single_range_for_{cpu,device}. This
is intended to support an x86_64 implementation of
dma_sync_single_range_for_{cpu,device}.
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

The implementations of swiotlb_sync_single_for_{cpu,device} are
identical. Likewise for swiotlb_syng_sg_for_{cpu,device}. This patch
move the guts of those functions to two new inline functions, and
calls the appropriate one from the bodies of those functions.
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

The swiotlb implementation is shared by both IA-64 and EM64T. However,
the source itself lives under arch/ia64. This patch moves swiotlb.c
from arch/ia64/lib to lib/ and fixes-up the appropriate Makefile and
Kconfig files. No actual changes are made to swiotlb.c.
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Machine vector selection has always been a bit of a hack given how
early in system boot it needs to be done.  Services like ACPI namespace
are not available and there are non-trivial problems to moving them to
early boot.  However, there's no reason we can't change to a different
machvec later in boot when the services we need are available.  By
adding a entry point for later initialization of the swiotlb, we can add
an error path for the hpzx1 machevec initialization and fall back to the
DIG machine vector if IOMMU hardware isn't found in the system.  Since
ia64 uses 4GB for zone DMA (no ISA support), it's trivial to allocate a
contiguous range from the slab for bounce buffer usage.
Signed-off-by: NAlex Williamson <alex.williamson@hp.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

   Fix swiotlb sizing to match what the comments and the kernel
parameters documentation indicate.  Given a default 16k page size kernel
(ia64) and a 2k swiotlb page size, we're off by a multiple of 8 trying
to size the swiotlb.  When specified on the boot line, the swiotlb is
made 8x bigger than requested.  When left to the default value, it's 8x
smaller than the comments indicate.  For x86_64 the multiplier would be
2x.  The patch below fixes this.  Now, what's a good default swiotlb
size?  Apparently we don't really need 64MB.
Signed-off-by: NAlex Williamson <alex.williamson@hp.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

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!