kernel/linux.git/drivers/iommu, branch linux-4.7.y

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

2016-09-24T08:09:41+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

2016-09-07T06:34:48+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

iommu/arm-smmu: Disable stalling faults for all endpoints

2016-09-07T06:34:48+00:00

commit 3714ce1d6655098ee69ede632883e5874d67e4ab upstream. Enabling stalling faults can result in hardware deadlock on poorly designed systems, particularly those with a PCI root complex upstream of the SMMU. Although it's not really Linux's job to save hardware integrators from their own misfortune, it *is* our job to stop userspace (e.g. VFIO clients) from hosing the system for everybody else, even if they might already be required to have elevated privileges. Given that the fault handling code currently executes entirely in IRQ context, there is nothing that can sensibly be done to recover from things like page faults anyway, so let's rip this code out for now and avoid the potential for deadlock. Fixes: 48ec83bcbcf5 ("iommu/arm-smmu: Add initial driver support for ARM SMMUv3 devices") Reported-by: Matt Evans Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman

iommu/arm-smmu: Fix CMDQ error handling

2016-09-07T06:34:48+00:00

commit aea2037e0d3e23c3be1498feae29f71ca997d9e6 upstream. In the unlikely event of a global command queue error, the ARM SMMUv3 driver attempts to convert the problematic command into a CMD_SYNC and resume the command queue. Unfortunately, this code is pretty badly broken: 1. It uses the index into the error string table as the CMDQ index, so we probably read the wrong entry out of the queue 2. The arguments to queue_write are the wrong way round, so we end up writing from the queue onto the stack. These happily cancel out, so the kernel is likely to stay alive, but the command queue will probably fault again when we resume. This patch fixes the error handling code to use the correct queue index and write back the CMD_SYNC to the faulting entry. Fixes: 48ec83bcbcf5 ("iommu/arm-smmu: Add initial driver support for ARM SMMUv3 devices") Reported-by: Diwakar Subraveti Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman

iommu/io-pgtable-arm-v7s: Fix attributes when splitting blocks

2016-09-07T06:34:48+00:00

commit e633fc7a1347528c3b4a6bbdeb41f5d63988242c upstream. Due to the attribute bits being all over the place in the different types of short-descriptor PTEs, when remapping an existing entry, e.g. splitting a section into pages, we take the approach of decomposing the PTE attributes back to the IOMMU API flags to start from scratch. On inspection, though, the existing code seems to have got the read-only bit backwards and ignored the XN bit. How embarrassing... Fortunately the primary user so far, the Mediatek IOMMU, both never splits blocks (because it only serves non-overlapping DMA API calls) and also ignores permissions anyway, but let's put things right before any future users trip up. Fixes: e5fc9753b1a8 ("iommu/io-pgtable: Add ARMv7 short descriptor support") Signed-off-by: Robin Murphy Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman

iommu/dma: Don't put uninitialised IOVA domains

2016-09-07T06:34:48+00:00

commit 3ec60043f7c02e1f79e4a90045ff2d2e80042941 upstream. Due to the limitations of having to wait until we see a device's DMA restrictions before we know how we want an IOVA domain initialised, there is a window for error if a DMA ops domain is allocated but later freed without ever being used. In that case, init_iova_domain() was never called, so calling put_iova_domain() from iommu_put_dma_cookie() ends up trying to take an uninitialised lock and crashing. Make things robust by skipping the call unless the IOVA domain actually has been initialised, as we probably should have done from the start. Fixes: 0db2e5d18f76 ("iommu: Implement common IOMMU ops for DMA mapping") Reported-by: Nate Watterson Reviewed-by: Nate Watterson Tested-by: Nate Watterson Reviewed-by: Eric Auger Tested-by: Eric Auger Signed-off-by: Robin Murphy Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman

iommu/amd: Update Alias-DTE in update_device_table()

2016-08-20T16:10:57+00:00

commit 3254de6bf74fe94c197c9f819fe62a3a3c36f073 upstream. Not doing so might cause IO-Page-Faults when a device uses an alias request-id and the alias-dte is left in a lower page-mode which does not cover the address allocated from the iova-allocator. Fixes: 492667dacc0a ('x86/amd-iommu: Remove amd_iommu_pd_table') Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman

iommu/amd: Init unity mappings only for dma_ops domains

2016-08-20T16:10:57+00:00

commit b548e786ce47017107765bbeb0f100202525ea83 upstream. The default domain for a device might also be identity-mapped. In this case the kernel would crash when unity mappings are defined for the device. Fix that by making sure the domain is a dma_ops domain. Fixes: 0bb6e243d7fb ('iommu/amd: Support IOMMU_DOMAIN_DMA type allocation') Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman

iommu/amd: Handle IOMMU_DOMAIN_DMA in ops->domain_free call-back

2016-08-20T16:10:57+00:00

commit cda7005ba2cbd0744fea343dd5b2aa637eba5b9e upstream. This domain type is not yet handled in the iommu_ops->domain_free() call-back. Fix that. Fixes: 0bb6e243d7fb ('iommu/amd: Support IOMMU_DOMAIN_DMA type allocation') Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman

iommu/io-pgtable-arm: Fix iova_to_phys for block entries

2016-08-20T16:10:57+00:00

commit 7c6d90e2bb1a98b86d73b9e8ab4d97ed5507e37c upstream. The implementation of iova_to_phys for the long-descriptor ARM io-pgtable code always masks with the granule size when inserting the low virtual address bits into the physical address determined from the page tables. In cases where the leaf entry is found before the final level of table (i.e. due to a block mapping), this results in rounding down to the bottom page of the block mapping. Consequently, the physical address range batching in the vfio_unmap_unpin is defeated and we end up taking the long way home. This patch fixes the problem by masking the virtual address with the appropriate mask for the level at which the leaf descriptor is located. The short-descriptor code already gets this right, so no change is needed there. Reported-by: Robin Murphy Tested-by: Robin Murphy Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman