The BIOS errors where an IOMMU is reported either at zero or a bogus
address are causing problems even when the IOMMU is disabled -- because
interrupt remapping uses the same hardware. Ensure that the checks get
applied for the interrupt remapping initialisation too.

Cc: stable@kernel.org
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Many BIOSes will lie to us about the existence of an IOMMU, and claim
that there is one at an address which actually returns all 0xFF.

We need to detect this early, so that we know we don't have a viable
IOMMU and can set up swiotlb before it's too late.

Cc: stable@kernel.org
Signed-off-by: NChris Wright <chrisw@sous-sol.org>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Commit ae21ee65 "PCI: acs p2p upsteram
forwarding enabling" doesn't actually enable ACS.

Add a function to pci core to allow an IOMMU to request that ACS
be enabled.  The existing mechanism of using iommu_found() in the pci
core to know when ACS should be enabled doesn't actually work due to
initialization order;  iommu has only been detected not initialized.

Have Intel and AMD IOMMUs request ACS, and Xen does as well during early
init of dom0.

Cc: Allen Kay <allen.m.kay@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NChris Wright <chrisw@sous-sol.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Change for PCI core to use pci_is_pcie() instead of checking
pci_dev->is_pcie.
Signed-off-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Commit 86cf898e ("intel-iommu: Check for
'DMAR at zero' BIOS error earlier.") was supposed to work by pretending
not to detect an IOMMU if it was actually being reported by the BIOS at
physical address zero.

However, the intel_iommu_init() function is called unconditionally, as
are the corresponding functions for other IOMMU hardware.

So the patch only worked if you have RAM above the 4GiB boundary. It
caused swiotlb to be initialised when no IOMMU was detected during early
boot, and thus the later IOMMU init would refuse to run.

But if you have less RAM than that, swiotlb wouldn't get set up and the
IOMMU _would_ still end up being initialised, even though we never
claimed to detect it.

This patch also sets the dmar_disabled flag when the error is detected
during the initial detection phase -- so that the later call to
intel_iommu_init() will return without doing anything, regardless of
whether swiotlb is used or not.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NFUJITA 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: NIngo Molnar <mingo@elte.hu>

This changes detect_intel_iommu() to set intel_iommu_init() to
iommu_init hook if detect_intel_iommu() finds the IOMMU.
Signed-off-by: NFUJITA 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: <1257849980-22640-6-git-send-email-fujita.tomonori@lab.ntt.co.jp>
[ -v2: build fix for the !CONFIG_DMAR case ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Chris Wright has some patches which let us fall back to swiotlb nicely
if IOMMU initialisation fails. But those are a bit much for 2.6.32.

Instead, let's shift the check for the biggest problem, the HP and Acer
BIOS bug which reports a DMAR at physical address zero. That one can
actually be checked much earlier -- before we even admit to having
detected an IOMMU in the first place. So the swiotlb init goes ahead as
we want.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Allocate queued invalidation descriptor structures using numa locality info.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Add support for parsing Remapping Hardware Static Affinity (RHSA) structure.
This enables identifying the association between remapping hardware units and
the corresponding proximity domain. This enables to allocate transalation
structures closer to the remapping hardware unit.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

I recently got a system where the DMAR table included a couple of RHSA
(remapping hardware static affinity) entries.  Rather than printing a
message about an "Unknown DMAR structure," it would probably be more
useful to dump the RHSA structure (as other DMAR structures are dumped).
Signed-off-by: NRoland Dreier <rolandd@cisco.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

We might as well print the type of the DMAR structure we don't know how
to handle when skipping it.  Then someone getting this message has a
chance of telling whether the structure is just bogus, or if there
really is something valid that the kernel doesn't know how to handle.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

users of acpi.h that need dmi.h should include it directly.
Signed-off-by: NLen Brown <len.brown@intel.com>

BIOS clear DMAR table INTR_REMAP flag to disable interrupt remapping. Current
kernel only check interrupt remapping(IR) flag in DRHD's extended capability
register to decide interrupt remapping support or not. But IR flag will not
change when BIOS disable/enable interrupt remapping.

When user disable interrupt remapping in BIOS or BIOS often defaultly disable
interrupt remapping feature when BIOS is not mature.Though BIOS disable
interrupt remapping but intr_remapping_supported function will always report
to OS support interrupt remapping if VT-d2 chipset populated. On this
cases, kernel will continue enable interrupt remapping and result kernel panic.
This bug exist on almost all platforms with interrupt remapping support.

This patch add DMAR table INTR_REMAP flag check before enable interrupt
remapping.
Signed-off-by: NYouquan Song <youquan.song@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Current kernel enable interrupt remapping only when all the vt-d unit support
interrupt remapping. So it is reasonable we should also disallow enabling
intr-remapping if there any io-apics that are not listed under vt-d units.
Otherwise we can run into issues.
Acked-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NYouquan Song <youquan.song@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

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: NShane Wang <shane.wang@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

DMAR faults are recorded into a ring of "fault recording registers".
fault_index is a 0-based index into the ring. The code allows the
0-based fault_index to be equal to the total number of fault registers
available from the cap_num_fault_regs() macro, which causes access
beyond the last available register.

Signed-off-by Troy Heber <troy.heber@hp.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Linux/ACPI core files using internal.h all PREFIX "ACPI: ",
however, not all ACPI drivers use/want it -- and they
should not have to #undef PREFIX to define their own.

Add GPL commment to internal.h while we are there.

This does not change any actual console output,
asside from a whitespace fix.
Signed-off-by: NLen Brown <len.brown@intel.com>

Yet another reason why trusting this stuff to the BIOS was a bad idea.
The HP DC7900 BIOS reports an iommu at an address which just returns all
ones, when VT-d is disabled in the BIOS.

Fix up the missing iounmap in the error paths while we're at it.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

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: NJoseph Cihula <joseph.cihula@intel.com>
Signed-off-by: NShane Wang <shane.wang@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Support device IOTLB invalidation to flush the translation cached
in the Endpoint.
Signed-off-by: NYu Zhao <yu.zhao@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Parse the Root Port ATS Capability Reporting Structure in the DMA
Remapping Reporting Structure ACPI table.
Signed-off-by: NYu Zhao <yu.zhao@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

dmar_set_interrupt feigns success when arch_setup_dmar_msi
fails, return error value.
Signed-off-by: NChris Wright <chrisw@sous-sol.org>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

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: NDavid Woodhouse <David.Woodhouse@intel.com>

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: NDavid Woodhouse <David.Woodhouse@intel.com>

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: NFenghua Yu <fenghua.yu@intel.com>
Acked-by: NWeidong Han <weidong@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

If the BIOS does something obviously stupid, like claiming that the
registers for the IOMMU are at physical address zero, then print a nasty
message and abort, rather than trying to set up the IOMMU and then later
panicking.

It's becoming more and more obvious that trusting this stuff to the BIOS
was a mistake.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

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: NDavid Woodhouse <David.Woodhouse@intel.com>

This patch supports queued invalidation suspend/resume.
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Impact: invalid use of GFP_KERNEL in interrupt context

Queued invalidation and interrupt-remapping will get initialized with
interrupts disabled (while enabling interrupt-remapping). So use
GFP_ATOMIC instead of GFP_KERNEL for memory alloacations.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Impact: cleanup/sanitization

Start from a sane state while enabling dma and interrupt-remapping, by
clearing the previous recorded faults and disabling previously
enabled queued invalidation and interrupt-remapping.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Impact: new interfaces (not yet used)

Routines for disabling queued invalidation and interrupt remapping.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Impact: interface augmentation (not yet used)

Enable fault handling flow for intr-remapping aswell. Fault handling
code now shared by both dma-remapping and intr-remapping.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Impact: code movement

Move page fault handling code to dmar.c
This will be shared both by DMA-remapping and Intr-remapping code.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

I have a SuperMicro C2SBX motherboard with BIOS revision 1.0b.  With vt-d
enabled in the BIOS, Linux gets into an endless loop printing
"DMAR:Unknown DMAR structure type" when booting.  Here is the DMAR ACPI
table:

DMAR @ 0x7fe86dec
  0000: 44 4d 41 52 98 00 00 00 01 6f 49 6e 74 65 6c 20  DMAR.....oIntel
  0010: 4f 45 4d 44 4d 41 52 20 00 00 04 06 4c 4f 48 52  OEMDMAR ....LOHR
  0020: 01 00 00 00 23 00 00 00 00 00 00 00 00 00 00 00  ....#...........
  0030: 01 00 58 00 00 00 00 00 00 a0 e8 7f 00 00 00 00  ..X.............
  0040: ff ff ef 7f 00 00 00 00 01 08 00 00 00 00 1d 00  ................
  0050: 01 08 00 00 00 00 1d 01 01 08 00 00 00 00 1d 02  ................
  0060: 01 08 00 00 00 00 1d 07 01 08 00 00 00 00 1a 00  ................
  0070: 01 08 00 00 00 00 1a 01 01 08 00 00 00 00 1a 02  ................
  0080: 01 08 00 00 00 00 1a 07 01 08 00 00 00 00 1a 07  ................
  0090: c0 00 68 00 04 10 66 60                          ..h...f`

Here are the messages printed by the kernel:

DMAR:Host address width 36
DMAR:RMRR base: 0x000000007fe8a000 end: 0x000000007fefffff
DMAR:Unknown DMAR structure type
DMAR:Unknown DMAR structure type
DMAR:Unknown DMAR structure type
...

Although I not very familiar with ACPI, to me it looks like struct
acpi_dmar_header::length == 0x0058 is incorrect, causing
parse_dmar_table() to look at an invalid offset on the next loop.  This
offset happens to have struct acpi_dmar_header::length == 0x0000, which
prevents the loop from ever terminating.  This patch checks for this
condition and bails out instead of looping forever.
Signed-off-by: NTony Battersby <tonyb@cybernetics.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Pawel reported:
------------[ cut here ]------------
WARNING: at arch/x86/mm/ioremap.c:616 check_early_ioremap_leak+0x52/0x67()
Hardware name:
Debug warning: early ioremap leak of 1 areas detected.
Modules linked in:
Pid: 1, comm: swapper Not tainted 2.6.29-rc4-tip #2
...
Reported-by: NPawel Dziekonski <dzieko@gmail.com>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

When hardware detects any error with a descriptor from the invalidation
queue, it stops fetching new descriptors from the queue until software
clears the Invalidation Queue Error bit in the Fault Status register.
Following fix handles the IQE so the kernel won't be trapped in an
infinite loop.
Signed-off-by: NYu Zhao <yu.zhao@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This fix should be safe since iommu->agaw is only used in intel-iommu.c.
And this file is only compiled with DMAR=y.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>