linux-toradex.git/drivers/iommu, branch v4.4.44

iommu/vt-d: Flush old iommu caches for kdump when the device gets context mapped

2017-01-12T10:22:49+00:00

commit aec0e86172a79eb5e44aff1055bb953fe4d47c59 upstream.

We met the DMAR fault both on hpsa P420i and P421 SmartArray controllers
under kdump, it can be steadily reproduced on several different machines,
the dmesg log is like:
HP HPSA Driver (v 3.4.16-0)
hpsa 0000:02:00.0: using doorbell to reset controller
hpsa 0000:02:00.0: board ready after hard reset.
hpsa 0000:02:00.0: Waiting for controller to respond to no-op
DMAR: Setting identity map for device 0000:02:00.0 [0xe8000 - 0xe8fff]
DMAR: Setting identity map for device 0000:02:00.0 [0xf4000 - 0xf4fff]
DMAR: Setting identity map for device 0000:02:00.0 [0xbdf6e000 - 0xbdf6efff]
DMAR: Setting identity map for device 0000:02:00.0 [0xbdf6f000 - 0xbdf7efff]
DMAR: Setting identity map for device 0000:02:00.0 [0xbdf7f000 - 0xbdf82fff]
DMAR: Setting identity map for device 0000:02:00.0 [0xbdf83000 - 0xbdf84fff]
DMAR: DRHD: handling fault status reg 2
DMAR: [DMA Read] Request device [02:00.0] fault addr fffff000 [fault reason 06] PTE Read access is not set
hpsa 0000:02:00.0: controller message 03:00 timed out
hpsa 0000:02:00.0: no-op failed; re-trying

After some debugging, we found that the fault addr is from DMA initiated at
the driver probe stage after reset(not in-flight DMA), and the corresponding
pte entry value is correct, the fault is likely due to the old iommu caches
of the in-flight DMA before it.

Thus we need to flush the old cache after context mapping is setup for the
device, where the device is supposed to finish reset at its driver probe
stage and no in-flight DMA exists hereafter.

I'm not sure if the hardware is responsible for invalidating all the related
caches allocated in the iommu hardware before, but seems not the case for hpsa,
actually many device drivers have problems in properly resetting the hardware.
Anyway flushing (again) by software in kdump kernel when the device gets context
mapped which is a quite infrequent operation does little harm.

With this patch, the problematic machine can survive the kdump tests.

CC: Myron Stowe 
CC: Joseph Szczypek 
CC: Don Brace 
CC: Baoquan He 
CC: Dave Young 
Fixes: 091d42e43d21 ("iommu/vt-d: Copy translation tables from old kernel")
Fixes: dbcd861f252d ("iommu/vt-d: Do not re-use domain-ids from the old kernel")
Fixes: cf484d0e6939 ("iommu/vt-d: Mark copied context entries")
Signed-off-by: Xunlei Pang 
Tested-by: Don Brace 
Signed-off-by: Joerg Roedel 
Signed-off-by: Greg Kroah-Hartman

iommu/vt-d: Fix pasid table size encoding

2017-01-12T10:22:49+00:00

commit 65ca7f5f7d1cdde6c25172fe6107cd16902f826f upstream.

Different encodings are used to represent supported PASID bits
and number of PASID table entries.
The current code assigns ecap_pss directly to extended context
table entry PTS which is wrong and could result in writing
non-zero bits to the reserved fields. IOMMU fault reason
11 will be reported when reserved bits are nonzero.
This patch converts ecap_pss to extend context entry pts encoding
based on VT-d spec. Chapter 9.4 as follows:
 - number of PASID bits = ecap_pss + 1
 - number of PASID table entries = 2^(pts + 5)
Software assigned limit of pasid_max value is also respected to
match the allocation limitation of PASID table.

cc: Mika Kuoppala 
cc: Ashok Raj 
Signed-off-by: Jacob Pan 
Tested-by: Mika Kuoppala 
Fixes: 2f26e0a9c9860 ('iommu/vt-d: Add basic SVM PASID support')
Signed-off-by: Joerg Roedel 
Signed-off-by: Greg Kroah-Hartman

iommu/amd: Fix the left value check of cmd buffer

2017-01-12T10:22:49+00:00

commit 432abf68a79332282329286d190e21fe3ac02a31 upstream.

The generic command buffer entry is 128 bits (16 bytes), so the offset
of tail and head pointer should be 16 bytes aligned and increased with
0x10 per command.

When cmd buf is full, head = (tail + 0x10) % CMD_BUFFER_SIZE.

So when left space of cmd buf should be able to store only two
command, we should be issued one COMPLETE_WAIT additionally to wait
all older commands completed. Then the left space should be increased
after IOMMU fetching from cmd buf.

So left check value should be left <= 0x20 (two commands).

Signed-off-by: Huang Rui 
Fixes: ac0ea6e92b222 ('x86/amd-iommu: Improve handling of full command buffer')
Signed-off-by: Joerg Roedel 
Signed-off-by: Greg Kroah-Hartman

iommu/amd: Missing error code in amd_iommu_init_device()

2017-01-12T10:22:49+00:00

commit 24c790fbf5d8f54c8c82979db11edea8855b74bf upstream.

We should set "ret" to -EINVAL if iommu_group_get() fails.

Fixes: 55c99a4dc50f ("iommu/amd: Use iommu_attach_group()")
Signed-off-by: Dan Carpenter 
Signed-off-by: Joerg Roedel 
Signed-off-by: Greg Kroah-Hartman

iommu/vt-d: Fix IOMMU lookup for SR-IOV Virtual Functions

2016-12-02T08:09:00+00:00

commit 1c387188c60f53b338c20eee32db055dfe022a9b upstream.

The VT-d specification (§8.3.3) says:
    ‘Virtual Functions’ of a ‘Physical Function’ are under the scope
    of the same remapping unit as the ‘Physical Function’.

The BIOS is not required to list all the possible VFs in the scope
tables, and arguably *shouldn't* make any attempt to do so, since there
could be a huge number of them.

This has been broken basically for ever — the VF is never going to match
against a specific unit's scope, so it ends up being assigned to the
INCLUDE_ALL IOMMU. Which was always actually correct by coincidence, but
now we're looking at Root-Complex integrated devices with SR-IOV support
it's going to start being wrong.

Fix it to simply use pci_physfn() before doing the lookup for PCI devices.

Signed-off-by: Sainath Grandhi 
Signed-off-by: Ashok Raj 
Signed-off-by: David Woodhouse 
Signed-off-by: Greg Kroah-Hartman

iommu/vt-d: Fix PASID table allocation

2016-12-02T08:09:00+00:00

commit 910170442944e1f8674fd5ddbeeb8ccd1877ea98 upstream.

Somehow I ended up with an off-by-three error in calculating the size of
the PASID and PASID State tables, which triggers allocations failures as
those tables unfortunately have to be physically contiguous.

In fact, even the *correct* maximum size of 8MiB is problematic and is
wont to lead to allocation failures. Since I have extracted a promise
that this *will* be fixed in hardware, I'm happy to limit it on the
current hardware to a maximum of 0x20000 PASIDs, which gives us 1MiB
tables — still not ideal, but better than before.

Reported by Mika Kuoppala  and also by
Xunlei Pang  who submitted a simpler patch to fix
only the allocation (and not the free) to the "correct" limit... which
was still problematic.

Signed-off-by: David Woodhouse 
Signed-off-by: Greg Kroah-Hartman

iommu/vt-d: Fix dead-locks in disable_dmar_iommu() path

2016-11-18T09:48:36+00:00

commit bea64033dd7b5fb6296eda8266acab6364ce1554 upstream.

It turns out that the disable_dmar_iommu() code-path tried
to get the device_domain_lock recursivly, which will
dead-lock when this code runs on dmar removal. Fix both
code-paths that could lead to the dead-lock.

Fixes: 55d940430ab9 ('iommu/vt-d: Get rid of domain->iommu_lock')
Signed-off-by: Joerg Roedel 
Signed-off-by: Greg Kroah-Hartman

iommu/amd: Free domain id when free a domain of struct dma_ops_domain

2016-11-18T09:48:36+00:00

commit c3db901c54466a9c135d1e6e95fec452e8a42666 upstream.

The current code missed freeing domain id when free a domain of
struct dma_ops_domain.

Signed-off-by: Baoquan He 
Fixes: ec487d1a110a ('x86, AMD IOMMU: add domain allocation and deallocation functions')
Signed-off-by: Joerg Roedel 
Signed-off-by: Greg Kroah-Hartman

Add braces to avoid "ambiguous ‘else’" compiler warnings

2016-09-30T08:18:35+00:00

commit 194dc870a5890e855ecffb30f3b80ba7c88f96d6 upstream.

Some of our "for_each_xyz()" macro constructs make gcc unhappy about
lack of braces around if-statements inside or outside the loop, because
the loop construct itself has a "if-then-else" statement inside of it.

The resulting warnings look something like this:

  drivers/gpu/drm/i915/i915_debugfs.c: In function ‘i915_dump_lrc’:
  drivers/gpu/drm/i915/i915_debugfs.c:2103:6: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses]
     if (ctx != dev_priv->kernel_context)
        ^

even if the code itself is fine.

Since the warning is fairly easy to avoid by adding a braces around the
if-statement near the for_each_xyz() construct, do so, rather than
disabling the otherwise potentially useful warning.

(The if-then-else statements used in the "for_each_xyz()" constructs are
designed to be inherently safe even with no braces, but in this case
it's quite understandable that gcc isn't really able to tell that).

This finally leaves the standard "allmodconfig" build with just a
handful of remaining warnings, so new and valid warnings hopefully will
stand out.

Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

iommu/arm-smmu: Don't BUG() if we find aborting STEs with disable_bypass

2016-09-07T06:32:41+00:00

commit 5bc0a11664e17e9f9551983f5b660bd48b57483c upstream.

The disable_bypass cmdline option changes the SMMUv3 driver to put down
faulting stream table entries by default, as opposed to bypassing
transactions from unconfigured devices.

In this mode of operation, it is entirely expected to see aborting
entries in the stream table if and when we come to installing a valid
translation, so don't trigger a BUG() as a result of misdiagnosing these
entries as stream table corruption.

Fixes: 48ec83bcbcf5 ("iommu/arm-smmu: Add initial driver support for ARM SMMUv3 devices")
Tested-by: Robin Murphy 
Reported-by: Robin Murphy 
Reviewed-by: Robin Murphy 
Signed-off-by: Will Deacon 
Signed-off-by: Greg Kroah-Hartman