Commit graph

250 commits

Author SHA1 Message Date
David Woodhouse
44cd613c0e intel-iommu: Fix oops with intel_iommu=igfx_off
The hotplug notifier will call find_domain() to see if the device in
question has been assigned an IOMMU domain. However, this should never
be called for devices with a "dummy" domain, such as graphics devices
when intel_iommu=igfx_off is set and the corresponding IOMMU isn't even
initialised. If you do that, it'll oops as it dereferences the (-1)
pointer.

The notifier function should check iommu_no_mapping() for the
device before doing anything else.

Cc: stable@kernel.org
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-12-08 10:03:06 +00:00
David Woodhouse
5595b528b4 intel-iommu: Check for an RMRR which ends before it starts.
Some HP BIOSes report an RMRR region (a region which needs a 1:1 mapping
in the IOMMU for a given device) which has an end address lower than its
start address. Detect that and warn, rather than triggering the
BUG() in dma_pte_clear_range().

Cc: stable@kernel.org
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-12-08 10:02:52 +00:00
David Woodhouse
ec20849193 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Merge the BIOS workarounds from 2.6.32, and the swiotlb fallback on failure.
2009-12-08 09:59:24 +00:00
Linus Torvalds
7b626acb8f Merge branch 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (63 commits)
  x86, Calgary IOMMU quirk: Find nearest matching Calgary while walking up the PCI tree
  x86/amd-iommu: Remove amd_iommu_pd_table
  x86/amd-iommu: Move reset_iommu_command_buffer out of locked code
  x86/amd-iommu: Cleanup DTE flushing code
  x86/amd-iommu: Introduce iommu_flush_device() function
  x86/amd-iommu: Cleanup attach/detach_device code
  x86/amd-iommu: Keep devices per domain in a list
  x86/amd-iommu: Add device bind reference counting
  x86/amd-iommu: Use dev->arch->iommu to store iommu related information
  x86/amd-iommu: Remove support for domain sharing
  x86/amd-iommu: Rearrange dma_ops related functions
  x86/amd-iommu: Move some pte allocation functions in the right section
  x86/amd-iommu: Remove iommu parameter from dma_ops_domain_alloc
  x86/amd-iommu: Use get_device_id and check_device where appropriate
  x86/amd-iommu: Move find_protection_domain to helper functions
  x86/amd-iommu: Simplify get_device_resources()
  x86/amd-iommu: Let domain_for_device handle aliases
  x86/amd-iommu: Remove iommu specific handling from dma_ops path
  x86/amd-iommu: Remove iommu parameter from __(un)map_single
  x86/amd-iommu: Make alloc_new_range aware of multiple IOMMUs
  ...
2009-12-05 09:49:07 -08:00
Kenji Kaneshige
5f4d91a122 PCI: use pci_is_pcie() in pci core
Change for PCI core to use pci_is_pcie() instead of checking
pci_dev->is_pcie.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-11-24 15:25:16 -08:00
Fenghua Yu
99dcadede4 intel-iommu: Support PCIe hot-plug
To support PCIe hot plug in IOMMU, we register a notifier to respond to device
change action.

When the notifier gets BUS_NOTIFY_UNBOUND_DRIVER, it removes the device
from its DMAR domain.

A hot added device will be added into an IOMMU domain when it first does IOMMU
op. So there is no need to add more code for hot add.

Without the patch, after a hot-remove, a hot-added device on the same
slot will not work.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Tested-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-11-12 02:28:45 +00:00
Alex Williamson
e8bb910d1b intel-iommu: Obey coherent_dma_mask for alloc_coherent on passthrough
The model for IOMMU passthrough is that decent devices that can cope
with DMA to all of memory get passthrough; crappy devices with a limited
dma_mask don't -- they get to use the IOMMU anyway.

This is done on the basis that IOMMU passthrough is usually wanted for
performance reasons, and it's only the decent PCI devices that you
really care about performance for, while the crappy 32-bit ones like
your USB controller can just use the IOMMU and you won't really care.

Unfortunately, the check for this was only looking at dev->dma_mask, not
at dev->coherent_dma_mask. And some devices have a 32-bit
coherent_dma_mask even though they have a full 64-bit dma_mask.

Even more unfortunately, fixing that simple oversight would upset
certain broken HP devices. Not only do they have a 32-bit
coherent_dma_mask, but they also have a tendency to do stray DMA to
unmapped addresses. And then they die when they take the DMA fault they
so richly deserve.

So if we do the 'correct' fix, it'll mean that affected users have to
disable IOMMU support completely on "a large percentage of servers from
a major vendor."

Personally, I have little sympathy -- given that this is the _same_
'major vendor' who is shipping machines which claim to have IOMMU
support but have obviously never _once_ booted a VT-d capable OS to do
any form of QA. But strictly speaking, it _would_ be a regression even
though it only ever worked by fluke.

For 2.6.33, we'll come up with a quirk which gives swiotlb support
for this particular device, and other devices with an inadequate
coherent_dma_mask will just get normal IOMMU mapping.

The simplest fix for 2.6.32, though, is just to jump through some hoops
to try to allocate coherent DMA memory for such devices in a place that
they can reach. We'd use dma_generic_alloc_coherent() for this if it
existed on IA64.

Signed-off-by: Alex Williamson <alex.williamson@hp.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-11-12 02:10:34 +00:00
FUJITA Tomonori
75f1cdf1dd x86: Handle HW IOMMU initialization failure gracefully
If HW IOMMU initialization fails (Intel VT-d often does this,
typically due to BIOS bugs), we fall back to nommu. It doesn't
work for the majority since nowadays we have more than 4GB
memory so we must use swiotlb instead of nommu.

The problem is that it's too late to initialize swiotlb when HW
IOMMU initialization fails. We need to allocate swiotlb memory
earlier from bootmem allocator. Chris explained the issue in
detail:

  http://marc.info/?l=linux-kernel&m=125657444317079&w=2

The current x86 IOMMU initialization sequence is too complicated
and handling the above issue makes it more hacky.

This patch changes x86 IOMMU initialization sequence to handle
the above issue cleanly.

The new x86 IOMMU initialization sequence are:

1. we initialize the swiotlb (and setting swiotlb to 1) in the case
   of (max_pfn > MAX_DMA32_PFN && !no_iommu). dma_ops is set to
   swiotlb_dma_ops or nommu_dma_ops. if swiotlb usage is forced by
   the boot option, we finish here.

2. we call the detection functions of all the IOMMUs

3. the detection function sets x86_init.iommu.iommu_init to the
   IOMMU initialization function (so we can avoid calling the
   initialization functions of all the IOMMUs needlessly).

4. if the IOMMU initialization function doesn't need to swiotlb
   then sets swiotlb to zero (e.g. the initialization is
   sucessful).

5. if we find that swiotlb is set to zero, we free swiotlb
   resource.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: chrisw@sous-sol.org
Cc: dwmw2@infradead.org
Cc: joerg.roedel@amd.com
Cc: muli@il.ibm.com
LKML-Reference: <1257849980-22640-10-git-send-email-fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-10 12:32:07 +01:00
Suresh Siddha
4c923d4714 iommu: Allocate dma-remapping structures using numa locality info
Allocate dma-remapping structures using numa locality info. On platforms
having remapping hardware units span different nodes, this enables
optimized dma-remapping transalation structures access by remapping hardware.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-10-05 07:55:33 +01:00
David Woodhouse
e0fc7e0b4b intel-iommu: Yet another BIOS workaround: Isoch DMAR unit with no TLB space
Asus decided to ship a BIOS which configures sound DMA to go via the
dedicated IOMMU unit, but assigns precisely zero TLB entries to that
unit. Which causes the whole thing to deadlock, including the DMA
traffic on the _other_ IOMMU units. Nice one.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-09-30 09:12:17 -07:00
Linus Torvalds
b09a75fc5e Merge git://git.infradead.org/iommu-2.6
* git://git.infradead.org/iommu-2.6: (23 commits)
  intel-iommu: Disable PMRs after we enable translation, not before
  intel-iommu: Kill DMAR_BROKEN_GFX_WA option.
  intel-iommu: Fix integer wrap on 32 bit kernels
  intel-iommu: Fix integer overflow in dma_pte_{clear_range,free_pagetable}()
  intel-iommu: Limit DOMAIN_MAX_PFN to fit in an 'unsigned long'
  intel-iommu: Fix kernel hang if interrupt remapping disabled in BIOS
  intel-iommu: Disallow interrupt remapping if not all ioapics covered
  intel-iommu: include linux/dmi.h to use dmi_ routines
  pci/dmar: correct off-by-one error in dmar_fault()
  intel-iommu: Cope with yet another BIOS screwup causing crashes
  intel-iommu: iommu init error path bug fixes
  intel-iommu: Mark functions with __init
  USB: Work around BIOS bugs by quiescing USB controllers earlier
  ia64: IOMMU passthrough mode shouldn't trigger swiotlb init
  intel-iommu: make domain_add_dev_info() call domain_context_mapping()
  intel-iommu: Unify hardware and software passthrough support
  intel-iommu: Cope with broken HP DC7900 BIOS
  iommu=pt is a valid early param
  intel-iommu: double kfree()
  intel-iommu: Kill pointless intel_unmap_single() function
  ...

Fixed up trivial include lines conflict in drivers/pci/intel-iommu.c
2009-09-23 10:06:10 -07:00
David Woodhouse
b94996c99c intel-iommu: Disable PMRs after we enable translation, not before
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-09-19 15:28:12 -07:00
Benjamin LaHaise
64de5af000 intel-iommu: Fix integer wrap on 32 bit kernels
The following 64 bit promotions are necessary to handle memory above the
4GiB boundary correctly.

[dwmw2: Fix the second part not to need 64-bit arithmetic at all]

Signed-off-by: Benjamin LaHaise <ben.lahaise@neterion.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-09-19 09:26:20 -07:00
David Woodhouse
59c36286b7 intel-iommu: Fix integer overflow in dma_pte_{clear_range,free_pagetable}()
If end_pfn is equal to (unsigned long)-1, then the loop will never end.

Seen on 32-bit kernel, but could have happened on 64-bit too once we get
hardware that supports 64-bit guest addresses.

Change both functions to a 'do {} while' loop with the test at the end,
and check for the PFN having wrapper round to zero.

Reported-by: Benjamin LaHaise <ben.lahaise@neterion.com>
Tested-by: Benjamin LaHaise <ben.lahaise@neterion.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-09-19 07:36:28 -07:00
David Woodhouse
2ebe31513f intel-iommu: Limit DOMAIN_MAX_PFN to fit in an 'unsigned long'
This means we're limited to 44-bit addresses on 32-bit kernels, and
makes it sane for us to use 'unsigned long' for PFNs throughout.

Which is just as well, really, since we already do that.

Reported-by: Benjamin LaHaise <ben.lahaise@neterion.com>
Tested-by: Benjamin LaHaise <ben.lahaise@neterion.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-09-19 07:34:04 -07:00
Ingo Molnar
936e894a97 Merge commit 'v2.6.31-rc8' into x86/txt
Conflicts:
	arch/x86/kernel/reboot.c
	security/Kconfig

Merge reason: resolve the conflicts, bump up from rc3 to rc8.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-02 08:17:56 +02:00
Shane Wang
69575d3886 x86, intel_txt: clean up the impact on generic code, unbreak non-x86
Move tboot.h from asm to linux to fix the build errors of intel_txt
patch on non-X86 platforms. Remove the tboot code from generic code
init/main.c and kernel/cpu.c.

Signed-off-by: Shane Wang <shane.wang@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-09-01 18:25:07 -07:00
Stephen Rothwell
adb2fe0277 intel-iommu: include linux/dmi.h to use dmi_ routines
This file needs to include linux/dmi.h directly rather than relying on
it being pulled in from elsewhere.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-08-31 10:50:01 +01:00
David Woodhouse
2ff729f544 intel-iommu: Cope with yet another BIOS screwup causing crashes
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-08-26 14:25:41 +01:00
Donald Dutile
94a91b5051 intel-iommu: iommu init error path bug fixes
The kcalloc() failure path in iommu_init_domains() calls
free_dmar_iommu(), which assumes that ->domains, ->domain_ids,
and ->lock have been properly initialized.

Add checks in free_[dmar]_iommu to not use ->domains,->domain_ids
if not alloced. Move the lock init to prior to the kcalloc()'s,
so it is valid in free_context_table() when free_dmar_iommu() invokes
it at the end.

Patch based on iommu-2.6,
commit 132032274a

Signed-off-by: Donald Dutile <ddutile@redhat.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-08-24 08:56:26 +01:00
Matt Kraai
071e13746f intel-iommu: Mark functions with __init
Mark si_domain_init and iommu_prepare_static_identity_mapping with
__init, to eliminate the following warnings:

WARNING: drivers/pci/built-in.o(.text+0xf1f4): Section mismatch in reference from the function si_domain_init() to the function .init.text:si_domain_work_fn()
The function si_domain_init() references
the function __init si_domain_work_fn().
This is often because si_domain_init lacks a __init
annotation or the annotation of si_domain_work_fn is wrong.

WARNING: drivers/pci/built-in.o(.text+0xe340): Section mismatch in reference from the function iommu_prepare_static_identity_mapping() to the function .init.text:si_domain_init()
The function iommu_prepare_static_identity_mapping() references
the function __init si_domain_init().
This is often because iommu_prepare_static_identity_mapping lacks a __init
annotation or the annotation of si_domain_init is wrong.

Signed-off-by: Matt Kraai <kraai@ftbfs.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-08-24 08:54:34 +01:00
David Woodhouse
5fe60f4e58 intel-iommu: make domain_add_dev_info() call domain_context_mapping()
All callers of the former were also calling the latter, in one order or
the other, and failing to correctly clean up if the second returned
failure.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-08-09 10:53:50 +01:00
David Woodhouse
a131bc1855 Merge branch 'master' of /pub/scm/linux/kernel/git/torvalds/linux-2.6
Pull fixes in from 2.6.31 so that people testing the iommu-2.6.git tree
no longer trip over bugs which were already fixed (sorry, Horms).
2009-08-08 11:26:15 +01:00
Sheng Yang
c5b1525533 intel-iommu: Fix enabling snooping feature by mistake
Two defects work together result in KVM device passthrough randomly can't
work:
1. iommu_snooping is not initialized to zero when vm_iommu_init() called.
So it is possible to get a random value.
2. One line added by commit 2c2e2c38("IOMMU Identity Mapping Support")
change the code path, let it bypass domain_update_iommu_cap(), as well as
missing the increment of domain iommu reference count.

The latter is also likely to cause a leak of domains on repeated VMM 
assignment and deassignment.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-08-06 11:35:50 +01:00
Fenghua Yu
33041ec049 intel-iommu: Mask physical address to correct page size in intel_map_single()
The physical address passed to domain_pfn_mapping() should be rounded 
down to the start of the MM page, not the VT-d page.

This issue causes kernel panic on PAGE_SIZE>VTD_PAGE_SIZE platforms e.g. ia64
platforms.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-08-05 09:15:48 +01:00
Fenghua Yu
f532959b77 intel-iommu: Correct sglist size calculation.
In domain_sg_mapping(), use aligned_nrpages() instead of hand-coded
rounding code for calculating the size of each sg elem. This means that
on IA64 we correctly round up to the MM page size, not just to the VT-d
page size.

Also remove the incorrect mm_to_dma_pfn() when intel_map_sg() calls
domain_sg_mapping() -- the 'size' variable is in VT-d pages already.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-08-05 08:59:47 +01:00
David Woodhouse
19943b0e30 intel-iommu: Unify hardware and software passthrough support
This makes the hardware passthrough mode work a lot more like the
software version, so that the behaviour of a kernel with 'iommu=pt'
is the same whether the hardware supports passthrough or not.

In particular:
 - We use a single si_domain for the pass-through devices.
 - 32-bit devices can be taken out of the pass-through domain so that
   they don't have to use swiotlb.
 - Devices will work again after being removed from a KVM guest.
 - A potential oops on OOM (in init_context_pass_through()) is fixed.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-08-04 16:19:23 +01:00
Joseph Cihula
a59b50e995 intel_txt: Force IOMMU on for Intel TXT launch
The tboot module will DMA protect all of memory in order to ensure the that
kernel will be able to initialize without compromise (from DMA).  Consequently,
the kernel must enable Intel Virtualization Technology for Directed I/O
(VT-d or Intel IOMMU) in order to replace this broad protection with the
appropriate page-granular protection.  Otherwise DMA devices will be unable
to read or write from memory and the kernel will eventually panic.

Because runtime IOMMU support is configurable by command line options, this
patch will force it to be enabled regardless of the options specified, and will
log a message if it was required to force it on.

 dmar.c        |    7 +++++++
 intel-iommu.c |   17 +++++++++++++++--
 2 files changed, 22 insertions(+), 2 deletions(-)

Signed-off-by: Joseph Cihula <joseph.cihula@intel.com>
Signed-off-by: Shane Wang <shane.wang@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-07-21 11:50:42 -07:00
Dan Carpenter
86f4d0123b intel-iommu: double kfree()
g_iommus is freed after we "goto error;".

Found by smatch (http://repo.or.cz/w/smatch.git).

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-20 05:01:20 +01:00
David Woodhouse
0db9b7aebb intel-iommu: Kill pointless intel_unmap_single() function
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-15 08:17:26 +01:00
David Woodhouse
acea0018a2 intel-iommu: Defer the iotlb flush and iova free for intel_unmap_sg() too.
I see no reason why we did this _only_ in intel_unmap_page().

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-15 08:17:23 +01:00
David Woodhouse
3d39cecc48 intel-iommu: Remove superfluous iova_alloc_lock from IOVA code
We only ever obtain this lock immediately before the iova_rbtree_lock,
and release it immediately after the iova_rbtree_lock. So ditch it and
just use iova_rbtree_lock.

[v2: Remove the lockdep bits this time too]
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-15 08:17:02 +01:00
Sheng Yang
4b99d35270 intel-iommu: Fix intel_iommu_unmap_range() with size 0
After some API change, intel_iommu_unmap_range() introduced a assumption that
parameter size != 0, otherwise the dma_pte_clean_range() would have a
overflowed argument. But the user like KVM don't have this assumption before,
then some BUG() triggered.

Fix it by ignoring size = 0.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-08 09:35:10 -07:00
David Woodhouse
147202aa77 intel-iommu: Speed up map routines by using cached domain ASAP
We did before, in the end -- but it was at the bottom of a long stack of
functions. Add an inline wrapper get_valid_domain_for_dev() which will
use the cached one _first_ and only make the out-of-line call if it's
not already set.

This takes the average time taken for a 1-page intel_map_sg() from 5961
cycles to 4812 cycles on my Lenovo x200s test box -- a modest 20%.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-07 19:43:24 +01:00
David Woodhouse
3dfc813d94 intel-iommu: Don't use identity mapping for PCI devices behind bridges
Our current strategy for pass-through mode is to put all devices into
the 1:1 domain at startup (which is before we know what their dma_mask
will be), and only _later_ take them out of that domain, if it turns out
that they really can't address all of memory.

However, when there are a bunch of PCI devices behind a bridge, they all
end up with the same source-id on their DMA transactions, and hence in
the same IOMMU domain. This means that we _can't_ easily move them from
the 1:1 domain into their own domain at runtime, because there might be DMA
in-flight from their siblings.

So we have to adjust our pass-through strategy: For PCI devices not on
the root bus, and for the bridges which will take responsibility for
their transactions, we have to start up _out_ of the 1:1 domain, just in
case.

This fixes the BUG() we see when we have 32-bit-capable devices behind a
PCI-PCI bridge, and use the software identity mapping.

It does mean that we might end up using 'normal' mapping mode for some
devices which could actually live with the faster 1:1 mapping -- but
this is only for PCI devices behind bridges, which presumably aren't the
devices for which people are most concerned about performance.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-04 19:19:10 +01:00
David Woodhouse
6941af2810 intel-iommu: Use iommu_should_identity_map() at startup time too.
At boot time, the dma_mask won't have been set on any devices, so we
assume that all devices will be 64-bit capable (and thus get a 1:1 map).

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-04 19:19:08 +01:00
David Woodhouse
736768325e intel-iommu: No mapping for non-PCI devices
This should fix kernel.org bug #11821, where the dcdbas driver makes up
a platform device and then uses dma_alloc_coherent() on it, in an
attempt to get memory < 4GiB.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-04 14:12:01 +01:00
David Woodhouse
62edf5dc4a intel-iommu: Restore DMAR_BROKEN_GFX_WA option for broken graphics drivers
We need to give people a little more time to fix the broken drivers.
Re-introduce this, but tied in properly with the 'iommu=pt' support this
time. Change the config option name and make it default to 'no' too.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-04 10:59:46 +01:00
David Woodhouse
40e4aa3432 intel-iommu: Add iommu_should_identity_map() function
We do this twice, and it's about to get more complicated. This makes the
code slightly clearer about what it's doing, too.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-04 10:55:41 +01:00
David Woodhouse
1b7bc0a161 intel-iommu: Fix reattaching of devices to identity mapping domain
When we reattach a device to the si_domain (because it's been removed
from a VM), we weren't calling domain_context_mapping() to actually tell
the hardware about that.

We should really put the call to domain_context_mapping() into
domain_add_dev_info() -- we never call the latter without also doing the
former, and we can keep the error paths simple that way. But that's a
cleanup which can wait for 2.6.32 now.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-04 10:49:46 +01:00
David Woodhouse
1e4c64c46d intel-iommu: Don't set identity mapping for bypassed graphics devices
We should check iommu_dummy() _first_, because that means it's attached
to an iommu that we've just disabled completely. At the moment, we might
try to put the device into the identity mapping domain.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-04 10:40:44 +01:00
David Woodhouse
5a5e02a614 intel-iommu: Fix dma vs. mm page confusion with aligned_nrpages()
The aligned_nrpages() function rounds up to the next VM page, but
returns its result as a number of DMA pages.

Purely theoretical except on IA64, which doesn't boot with VT-d right
now anyway.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-04 09:35:52 +01:00
David Woodhouse
6a43e574c5 intel-iommu: Don't keep freeing page zero in dma_pte_free_pagetable()
Check dma_pte_present() and only free the page if there _is_ one.
Kind of surprising that there was no warning about this.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-02 12:02:38 +01:00
David Woodhouse
75e6bf9638 intel-iommu: Introduce first_pte_in_page() to simplify PTE-setting loops
On Wed, 2009-07-01 at 16:59 -0700, Linus Torvalds wrote:
> I also _really_ hate how you do
>
>         (unsigned long)pte >> VTD_PAGE_SHIFT ==
>         (unsigned long)first_pte >> VTD_PAGE_SHIFT

Kill this, in favour of just looking to see if the incremented pte
pointer has 'wrapped' onto the next page. Which means we have to check
it _after_ incrementing it, not before.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-02 11:27:13 +01:00
David Woodhouse
7766a3fb90 intel-iommu: Use cmpxchg64_local() for setting PTEs
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-01 20:27:03 +01:00
David Woodhouse
85b98276f2 intel-iommu: Warn about unmatched unmap requests
This would have found the bug in i386 pci_unmap_addr() a long time ago.
We shouldn't just silently return without doing anything.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-01 19:54:37 +01:00
David Woodhouse
206a73c102 intel-iommu: Kill superfluous mapping_lock
Since we're using cmpxchg64() anyway (because that's the only way to do
an atomic 64-bit store on i386), we might as well ditch the extra
locking and just use cmpxchg64() to ensure that we don't add the page
twice.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-01 19:43:37 +01:00
David Woodhouse
c85994e477 intel-iommu: Ensure that PTE writes are 64-bit atomic, even on i386
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-07-01 19:21:24 +01:00
David Woodhouse
f3a0a52fff intel-iommu: Performance improvement for dma_pte_free_pagetable()
As with other functions, batch the CPU data cache flushes and don't keep
recalculating PTE addresses.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-30 03:58:15 +01:00
David Woodhouse
3d7b0e4154 intel-iommu: Don't free too much in dma_pte_free_pagetable()
The loop condition was wrong -- we should free a PMD only if its
_entire_ range is within the range we're intending to clear. The
early-termination condition was right, but not the loop.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-30 03:57:38 +01:00
David Woodhouse
1bf20f0dc5 intel-iommu: dump mappings but don't die on pte already set
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-30 03:55:21 +01:00
David Woodhouse
9051aa0268 intel-iommu: Combine domain_pfn_mapping() and domain_sg_mapping()
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-30 03:53:31 +01:00
David Woodhouse
e1605495c7 intel-iommu: Introduce domain_sg_mapping() to speed up intel_map_sg()
Instead of calling domain_pfn_mapping() repeatedly with single or
small numbers of pages, just pass the sglist in. It can optimise the
number of cache flushes like domain_pfn_mapping() does, and gives a huge
speedup for large scatterlists.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-30 03:51:30 +01:00
David Woodhouse
875764de6f intel-iommu: Simplify __intel_alloc_iova()
There's no need for the separate iommu_alloc_iova() function, and
certainly not for it to be global. Remove the underscores while we're at
it.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:39:53 +01:00
David Woodhouse
6f6a00e40a intel-iommu: Performance improvement for domain_pfn_mapping()
As with dma_pte_clear_range(), don't keep flushing a single PTE at a
time. And also micro-optimise the setting of PTE values rather than
using the helper functions to do all the masking.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:39:45 +01:00
David Woodhouse
310a5ab93c intel-iommu: Performance improvement for dma_pte_clear_range()
It's a bit silly to repeatedly call domain_flush_cache() for each PTE
individually, as we clear it. Instead, batch them up and flush a whole
range at a time. We might as well refrain from recalculating the PTE
address from scratch each time round the loop too.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:39:17 +01:00
David Woodhouse
c5395d5c4a intel-iommu: Clean up iommu_domain_identity_map()
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:39:12 +01:00
David Woodhouse
1a4a45516d intel-iommu: Remove last use of PHYSICAL_PAGE_MASK, for reserving PCI BARs
This is fairly broken anyway -- it doesn't take hotplug into account.
We should probably be checking page_is_ram() instead.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:39:05 +01:00
David Woodhouse
03d6a2461a intel-iommu: Make iommu_flush_iotlb_psi() take pfn as argument
Most of its callers are having to shift for themselves anyway, so we might
as well do it in iommu_flush_iotlb_psi().

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:38:11 +01:00
David Woodhouse
88cb6a7424 intel-iommu: Change aligned_size() to aligned_nrpages()
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:38:04 +01:00
David Woodhouse
b536d24d21 intel-iommu: Clean up intel_map_sg(), remove domain_page_mapping()
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:35:06 +01:00
David Woodhouse
ad05122162 intel-iommu: Use domain_pfn_mapping() in intel_iommu_map_range()
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:35:00 +01:00
David Woodhouse
0ab36de274 intel-iommu: Use domain_pfn_mapping() in __intel_map_single()
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:34:24 +01:00
David Woodhouse
61df744314 intel-iommu: Introduce domain_pfn_mapping()
... and use it in the trivial cases; the other callers want individual
(and bisectable) attention, since I screwed them up the first time...

Make the BUG_ON() happen on too-large virtual address rather than
physical address, too. That's the one we care about.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:33:59 +01:00
David Woodhouse
1c5a46ed49 intel-iommu: Clean up address handling in domain_page_mapping()
No more masking and alignment; just use pfns.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:33:11 +01:00
David Woodhouse
b026fd28ea intel-iommu: Change addr_to_dma_pte() to pfn_to_dma_pte()
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:32:26 +01:00
David Woodhouse
163cc52ccd intel-iommu: Clean up intel_iommu_unmap_range()
Use unaligned address for domain->max_addr. That algorithm isn't ideal
anyway -- we should probably just look at the last iova in the tree.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:31:12 +01:00
David Woodhouse
d794dc9b30 intel-iommu: Make dma_pte_free_pagetable() take pfns as argument
With some cleanup of intel_unmap_page(), intel_unmap_sg() and
vm_domain_exit() to no longer play with 64-bit addresses.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:30:45 +01:00
David Woodhouse
6660c63a79 intel-iommu: Make dma_pte_free_pagetable() use pfns
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:30:35 +01:00
David Woodhouse
595badf5d6 intel-iommu: Make dma_pte_clear_range() take pfns as argument
Noting that this is now an _inclusive_ range.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:28:10 +01:00
David Woodhouse
04b18e65dd intel-iommu: Make dma_pte_clear_range() use pfns
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 13:26:36 +01:00
David Woodhouse
66eae8469e intel-iommu: Don't just mask out too-big physical addresses; BUG() instead
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 12:38:42 +01:00
David Woodhouse
a75f7cf94f intel-iommu: Make dma_pte_clear_one() take pfn not address
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 12:38:40 +01:00
David Woodhouse
90dcfb5eb2 intel-iommu: Change dma_addr_level_pte() to dma_pfn_level_pte()
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 12:38:38 +01:00
David Woodhouse
77dfa56c94 intel-iommu: Change address_level_offset() to pfn_level_offset()
We're shifting the inputs for now, but that'll change...

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 12:38:32 +01:00
David Woodhouse
dd4e831960 intel-iommu: Change dma_set_pte_addr() to dma_set_pte_pfn()
Add some helpers for converting between VT-d and normal system pfns,
since system pages can be larger than VT-d pages.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 12:38:11 +01:00
David Woodhouse
c7ab48d2ac intel-iommu: Clean up identity mapping code, remove CONFIG_DMAR_GFX_WA
There's no need for the GFX workaround now we have 'iommu=pt' for the
cases where people really care about performance. There's no need to
have a special case for just one type of device.

This also speeds up the iommu=pt path and reduces memory usage by
setting up the si_domain _once_ and then using it for all devices,
rather than giving each device its own private page tables.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 12:37:44 +01:00
David Woodhouse
b213203e47 intel-iommu: Create new iommu_domain_identity_map() function
We'll want to do this to a _domain_ (the si_domain) rather than a PCI device.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 12:37:42 +01:00
Yu Zhao
bf92df30df intel-iommu: Only avoid flushing device IOTLB for domain ID 0 in caching mode
In caching mode, domain ID 0 is reserved for non-present to present
mapping flush. Device IOTLB doesn't need to be flushed in this case.

Previously we were avoiding the flush for domain zero, even if the IOMMU 
wasn't in caching mode and domain zero wasn't special.

Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-29 12:34:11 +01:00
Chris Wright
7e25a24229 intel-iommu: fix Identity Mapping to be arch independent
Drop the e820 scanning and use existing function for finding valid
RAM regions to add to 1:1 mapping.

Signed-off-by: Chris Wright <chrisw@redhat.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-26 11:26:27 +01:00
Fenghua Yu
2c2e2c389d IOMMU Identity Mapping Support (drivers/pci/intel_iommu.c)
Identity mapping for IOMMU defines a single domain to 1:1 map all PCI
devices to all usable memory.

This reduces map/unmap overhead in DMA API's and improve IOMMU
performance. On 10Gb network cards, Netperf shows no performance
degradation compared to non-IOMMU performance.

This method may lose some of DMA remapping benefits like isolation.

The patch sets up identity mapping for all PCI devices to all usable
memory. In the DMA API, there is no overhead to maintain page tables,
invalidate iotlb, flush cache etc.

32 bit DMA devices don't use identity mapping domain, in order to access
memory beyond 4GiB.

When kernel option iommu=pt, pass through is first tried. If pass
through succeeds, IOMMU goes to pass through. If pass through is not
supported in hw or fail for whatever reason, IOMMU goes to identity
mapping.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-06-23 22:07:54 +01:00
Linus Torvalds
687d680985 Merge git://git.infradead.org/~dwmw2/iommu-2.6.31
* git://git.infradead.org/~dwmw2/iommu-2.6.31:
  intel-iommu: Fix one last ia64 build problem in Pass Through Support
  VT-d: support the device IOTLB
  VT-d: cleanup iommu_flush_iotlb_psi and flush_unmaps
  VT-d: add device IOTLB invalidation support
  VT-d: parse ATSR in DMA Remapping Reporting Structure
  PCI: handle Virtual Function ATS enabling
  PCI: support the ATS capability
  intel-iommu: dmar_set_interrupt return error value
  intel-iommu: Tidy up iommu->gcmd handling
  intel-iommu: Fix tiny theoretical race in write-buffer flush.
  intel-iommu: Clean up handling of "caching mode" vs. IOTLB flushing.
  intel-iommu: Clean up handling of "caching mode" vs. context flushing.
  VT-d: fix invalid domain id for KVM context flush
  Fix !CONFIG_DMAR build failure introduced by Intel IOMMU Pass Through Support
  Intel IOMMU Pass Through Support

Fix up trivial conflicts in drivers/pci/{intel-iommu.c,intr_remapping.c}
2009-06-22 21:38:22 -07:00
Ingo Molnar
3d58f48ba0 Merge branch 'linus' into irq/numa
Conflicts:
	arch/mips/sibyte/bcm1480/irq.c
	arch/mips/sibyte/sb1250/irq.c

Merge reason: we gathered a few conflicts plus update to latest upstream fixes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-01 21:06:21 +02:00
Yu Zhao
93a23a7271 VT-d: support the device IOTLB
Enable the device IOTLB (i.e. ATS) for both the bare metal and KVM
environments.

Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-05-18 14:46:26 +01:00
Yu Zhao
9dd2fe8906 VT-d: cleanup iommu_flush_iotlb_psi and flush_unmaps
Make iommu_flush_iotlb_psi() and flush_unmaps() more readable.

Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-05-18 14:46:00 +01:00
David Woodhouse
fd18de50b9 intel-iommu: PAE memory corruption fix
PAGE_MASK is 0xFFFFF000 on i386 -- even with PAE.

So it's not sufficient to ensure that you use phys_addr_t or uint64_t
everywhere you handle physical addresses -- you also have to avoid using
the construct 'addr & PAGE_MASK', because that will strip the high 32
bits of the address.

This patch avoids that problem by using PHYSICAL_PAGE_MASK instead of
PAGE_MASK where appropriate. It leaves '& PAGE_MASK' in a few instances
that don't matter -- where it's being used on the virtual bus addresses
we're dishing out, which are 32-bit anyway.

Since PHYSICAL_PAGE_MASK is not present on other architectures, we have
to define it (to PAGE_MASK) if it's not already defined.

Maybe it would be better just to fix PAGE_MASK for i386/PAE?

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-11 07:51:01 -07:00
David Woodhouse
c416daa98a intel-iommu: Tidy up iommu->gcmd handling
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-05-10 20:32:37 +01:00
David Woodhouse
462b60f6cc intel-iommu: Fix tiny theoretical race in write-buffer flush.
In iommu_flush_write_buffer() we read iommu->gcmd before taking the
register_lock, and then we mask in the WBF bit and write it to the
register.

There is a tiny chance that something else could have _changed_
iommu->gcmd before we take the lock, but after we read it. So we could
be undoing that change.

Never actually going to have happened in practice, since nothing else
changes that register at runtime -- aside from the write-buffer flush
it's only ever touched at startup for enabling translation, etc.

But worth fixing anyway.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-05-10 20:18:18 +01:00
David Woodhouse
1f0ef2aa18 intel-iommu: Clean up handling of "caching mode" vs. IOTLB flushing.
As we just did for context cache flushing, clean up the logic around
whether we need to flush the iotlb or just the write-buffer, depending
on caching mode.

Fix the same bug in qi_flush_iotlb() that qi_flush_context() had -- it
isn't supposed to be returning an error; it's supposed to be returning a
flag which triggers a write-buffer flush.

Remove some superfluous conditional write-buffer flushes which could
never have happened because they weren't for non-present-to-present
mapping changes anyway.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-05-10 19:58:49 +01:00
David Woodhouse
4c25a2c1b9 intel-iommu: Clean up handling of "caching mode" vs. context flushing.
It really doesn't make a lot of sense to have some of the logic to
handle caching vs. non-caching mode duplicated in qi_flush_context() and
__iommu_flush_context(), while the return value indicates whether the
caller should take other action which depends on the same thing.

Especially since qi_flush_context() thought it was returning something
entirely different anyway.

This patch makes qi_flush_context() and __iommu_flush_context() both
return void, removes the 'non_present_entry_flush' argument and makes
the only call site which _set_ that argument to 1 do the right thing.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-05-10 19:49:52 +01:00
Yu Zhao
fa3b6dcd52 VT-d: fix invalid domain id for KVM context flush
The domain->id is a sequence number associated with the KVM guest
and should not be used for the context flush. This patch replaces
the domain->id with a proper id value for both bare metal and KVM.

Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Acked-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-05-10 15:55:09 +01:00
Fenghua Yu
aed5d5f4c5 Fix !CONFIG_DMAR build failure introduced by Intel IOMMU Pass Through Support
This updated patch should fix the compiling errors and remove the extern
iommu_pass_through from drivers/pci/intel-iommu.c file.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-05-01 16:44:47 +01:00
Fenghua Yu
4ed0d3e6c6 Intel IOMMU Pass Through Support
The patch adds kernel parameter intel_iommu=pt to set up pass through
mode in context mapping entry. This disables DMAR in linux kernel; but
KVM still runs on VT-d and interrupt remapping still works.

In this mode, kernel uses swiotlb for DMA API functions but other VT-d
functionalities are enabled for KVM. KVM always uses multi level
translation page table in VT-d. By default, pass though mode is disabled
in kernel.

This is useful when people don't want to enable VT-d DMAR in kernel but
still want to use KVM and interrupt remapping for reasons like DMAR
performance concern or debug purpose.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Weidong Han <weidong@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-04-29 06:54:34 +01:00
Weidong Han
937582382c x86, intr-remap: enable interrupt remapping early
Currently, when x2apic is not enabled, interrupt remapping
will be enabled in init_dmars(), where it is too late to remap
ioapic interrupts, that is, ioapic interrupts are really in
compatibility mode, not remappable mode.

This patch always enables interrupt remapping before ioapic
setup, it guarantees all interrupts will be remapped when
interrupt remapping is enabled. Thus it doesn't need to set
the compatibility interrupt bit.

[ Impact: refactor intr-remap init sequence, enable fuller remap mode ]

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Weidong Han <weidong.han@intel.com>
Acked-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: iommu@lists.linux-foundation.org
Cc: allen.m.kay@intel.com
Cc: fenghua.yu@intel.com
LKML-Reference: <1239957736-6161-4-git-send-email-weidong.han@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-19 10:21:43 +02:00
Linus Torvalds
7b11428d37 Merge git://git.infradead.org/iommu-2.6
* git://git.infradead.org/iommu-2.6:
  intel-iommu: Avoid panic() for DRHD at address zero.
  Intel-IOMMU Alignment Issue in dma_pte_clear_range()
2009-04-13 11:35:50 -07:00
Yang Hongyang
284901a90a dma-mapping: replace all DMA_32BIT_MASK macro with DMA_BIT_MASK(32)
Replace all DMA_32BIT_MASK macro with DMA_BIT_MASK(32)

Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07 08:31:11 -07:00
Yang Hongyang
6a35528a83 dma-mapping: replace all DMA_64BIT_MASK macro with DMA_BIT_MASK(64)
Replace all DMA_64BIT_MASK macro with DMA_BIT_MASK(64)

Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-07 08:31:10 -07:00
Fenghua Yu
31d3568dfe Intel-IOMMU Alignment Issue in dma_pte_clear_range()
This issue was pointed out by Linus.

In dma_pte_clear_range() in intel-iommu.c

start = PAGE_ALIGN(start);
end &= PAGE_MASK;
npages = (end - start) / VTD_PAGE_SIZE;

In partial page case, start could be bigger than end and npages will be
negative.

Currently the issue doesn't show up as a real bug in because start and 
end have been aligned to page boundary already by all callers. So the 
issue has been hidden. But it is dangerous programming practice.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-04-06 14:47:00 -07:00
David Woodhouse
4958c5dc7b intel-iommu: Fix oops in device_to_iommu() when devices not found.
It's possible for a device in the drhd->devices[] array to be NULL if
it wasn't found at boot time, which means we have to check for that
case.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-04-06 13:30:01 -07:00
David Woodhouse
276dbf9970 intel-iommu: Handle PCI domains appropriately.
We were comparing {bus,devfn} and assuming that a match meant it was the
same device. It doesn't -- the same {bus,devfn} can exist in
multiple PCI domains. Include domain number in device identification
(and call it 'segment' in most places, because there's already a lot of
references to 'domain' which means something else, and this code is
infected with ACPI thinking already).

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-04-04 10:43:31 +01:00