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'x86/vt-d' and 'core' into next
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Since IOVA allocation failure is not unusual case we need to flush
CPUs' rcache in hope we will succeed in next round.
However, it is useful to decide whether we need rcache flush step because
of two reasons:
- Not scalability. On large system with ~100 CPUs iterating and flushing
rcache for each CPU becomes serious bottleneck so we may want to defer it.
- free_cpu_cached_iovas() does not care about max PFN we are interested in.
Thus we may flush our rcaches and still get no new IOVA like in the
commonly used scenario:
if (dma_limit > DMA_BIT_MASK(32) && dev_is_pci(dev))
iova = alloc_iova_fast(iovad, iova_len, DMA_BIT_MASK(32) >> shift);
if (!iova)
iova = alloc_iova_fast(iovad, iova_len, dma_limit >> shift);
1. First alloc_iova_fast() call is limited to DMA_BIT_MASK(32) to get
PCI devices a SAC address
2. alloc_iova() fails due to full 32-bit space
3. rcaches contain PFNs out of 32-bit space so free_cpu_cached_iovas()
throws entries away for nothing and alloc_iova() fails again
4. Next alloc_iova_fast() call cannot take advantage of rcache since we
have just defeated caches. In this case we pick the slowest option
to proceed.
This patch reworks flushed_rcache local flag to be additional function
argument instead and control rcache flush step. Also, it updates all users
to do the flush as the last chance.
Signed-off-by: Tomasz Nowicki <Tomasz.Nowicki@caviumnetworks.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Nate Watterson <nwatters@codeaurora.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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Variable did_old is unsigned so checking whether it is
greater or equal to zero is not necessary.
Signed-off-by: Christos Gkekas <chris.gekas@gmail.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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The notifier function will take the dmar_global_lock too, so
lockdep complains about inverse locking order when the
notifier is registered under the dmar_global_lock.
Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Fixes: 59ce0515cdaf ('iommu/vt-d: Update DRHD/RMRR/ATSR device scope caches when PCI hotplug happens')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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Now that the cached node optimisation can apply to all allocations, the
couple of users which were playing tricks with dma_32bit_pfn in order to
benefit from it can stop doing so. Conversely, there is also no need for
all the other users to explicitly calculate a 'real' 32-bit PFN, when
init_iova_domain() can happily do that itself from the page granularity.
CC: Thierry Reding <thierry.reding@gmail.com>
CC: Jonathan Hunter <jonathanh@nvidia.com>
CC: David Airlie <airlied@linux.ie>
CC: Sudeep Dutt <sudeep.dutt@intel.com>
CC: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Zhen Lei <thunder.leizhen@huawei.com>
Tested-by: Nate Watterson <nwatters@codeaurora.org>
[rm: use iova_shift(), rewrote commit message]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull IOMMU updates from Joerg Roedel:
"Slightly more changes than usual this time:
- KDump Kernel IOMMU take-over code for AMD IOMMU. The code now tries
to preserve the mappings of the kernel so that master aborts for
devices are avoided. Master aborts cause some devices to fail in
the kdump kernel, so this code makes the dump more likely to
succeed when AMD IOMMU is enabled.
- common flush queue implementation for IOVA code users. The code is
still optional, but AMD and Intel IOMMU drivers had their own
implementation which is now unified.
- finish support for iommu-groups. All drivers implement this feature
now so that IOMMU core code can rely on it.
- finish support for 'struct iommu_device' in iommu drivers. All
drivers now use the interface.
- new functions in the IOMMU-API for explicit IO/TLB flushing. This
will help to reduce the number of IO/TLB flushes when IOMMU drivers
support this interface.
- support for mt2712 in the Mediatek IOMMU driver
- new IOMMU driver for QCOM hardware
- system PM support for ARM-SMMU
- shutdown method for ARM-SMMU-v3
- some constification patches
- various other small improvements and fixes"
* tag 'iommu-updates-v4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (87 commits)
iommu/vt-d: Don't be too aggressive when clearing one context entry
iommu: Introduce Interface for IOMMU TLB Flushing
iommu/s390: Constify iommu_ops
iommu/vt-d: Avoid calling virt_to_phys() on null pointer
iommu/vt-d: IOMMU Page Request needs to check if address is canonical.
arm/tegra: Call bus_set_iommu() after iommu_device_register()
iommu/exynos: Constify iommu_ops
iommu/ipmmu-vmsa: Make ipmmu_gather_ops const
iommu/ipmmu-vmsa: Rereserving a free context before setting up a pagetable
iommu/amd: Rename a few flush functions
iommu/amd: Check if domain is NULL in get_domain() and return -EBUSY
iommu/mediatek: Fix a build warning of BIT(32) in ARM
iommu/mediatek: Fix a build fail of m4u_type
iommu: qcom: annotate PM functions as __maybe_unused
iommu/pamu: Fix PAMU boot crash
memory: mtk-smi: Degrade SMI init to module_init
iommu/mediatek: Enlarge the validate PA range for 4GB mode
iommu/mediatek: Disable iommu clock when system suspend
iommu/mediatek: Move pgtable allocation into domain_alloc
iommu/mediatek: Merge 2 M4U HWs into one iommu domain
...
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git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI updates from Bjorn Helgaas:
- add enhanced Downstream Port Containment support, which prints more
details about Root Port Programmed I/O errors (Dongdong Liu)
- add Layerscape ls1088a and ls2088a support (Hou Zhiqiang)
- add MediaTek MT2712 and MT7622 support (Ryder Lee)
- add MediaTek MT2712 and MT7622 MSI support (Honghui Zhang)
- add Qualcom IPQ8074 support (Varadarajan Narayanan)
- add R-Car r8a7743/5 device tree support (Biju Das)
- add Rockchip per-lane PHY support for better power management (Shawn
Lin)
- fix IRQ mapping for hot-added devices by replacing the
pci_fixup_irqs() boot-time design with a host bridge hook called at
probe-time (Lorenzo Pieralisi, Matthew Minter)
- fix race when enabling two devices that results in upstream bridge
not being enabled correctly (Srinath Mannam)
- fix pciehp power fault infinite loop (Keith Busch)
- fix SHPC bridge MSI hotplug events by enabling bus mastering
(Aleksandr Bezzubikov)
- fix a VFIO issue by correcting PCIe capability sizes (Alex
Williamson)
- fix an INTD issue on Xilinx and possibly other drivers by unifying
INTx IRQ domain support (Paul Burton)
- avoid IOMMU stalls by marking AMD Stoney GPU ATS as broken (Joerg
Roedel)
- allow APM X-Gene device assignment to guests by adding an ACS quirk
(Feng Kan)
- fix driver crashes by disabling Extended Tags on Broadcom HT2100
(Extended Tags support is required for PCIe Receivers but not
Requesters, and we now enable them by default when Requesters support
them) (Sinan Kaya)
- fix MSIs for devices that use phantom RIDs for DMA by assuming MSIs
use the real Requester ID (not a phantom RID) (Robin Murphy)
- prevent assignment of Intel VMD children to guests (which may be
supported eventually, but isn't yet) by not associating an IOMMU with
them (Jon Derrick)
- fix Intel VMD suspend/resume by releasing IRQs on suspend (Scott
Bauer)
- fix a Function-Level Reset issue with Intel 750 NVMe by waiting
longer (up to 60sec instead of 1sec) for device to become ready
(Sinan Kaya)
- fix a Function-Level Reset issue on iProc Stingray by working around
hardware defects in the CRS implementation (Oza Pawandeep)
- fix an issue with Intel NVMe P3700 after an iProc reset by adding a
delay during shutdown (Oza Pawandeep)
- fix a Microsoft Hyper-V lockdep issue by polling instead of blocking
in compose_msi_msg() (Stephen Hemminger)
- fix a wireless LAN driver timeout by clearing DesignWare MSI
interrupt status after it is handled, not before (Faiz Abbas)
- fix DesignWare ATU enable checking (Jisheng Zhang)
- reduce Layerscape dependencies on the bootloader by doing more
initialization in the driver (Hou Zhiqiang)
- improve Intel VMD performance allowing allocation of more IRQ vectors
than present CPUs (Keith Busch)
- improve endpoint framework support for initial DMA mask, different
BAR sizes, configurable page sizes, MSI, test driver, etc (Kishon
Vijay Abraham I, Stan Drozd)
- rework CRS support to add periodic messages while we poll during
enumeration and after Function-Level Reset and prepare for possible
other uses of CRS (Sinan Kaya)
- clean up Root Port AER handling by removing unnecessary code and
moving error handler methods to struct pcie_port_service_driver
(Christoph Hellwig)
- clean up error handling paths in various drivers (Bjorn Andersson,
Fabio Estevam, Gustavo A. R. Silva, Harunobu Kurokawa, Jeffy Chen,
Lorenzo Pieralisi, Sergei Shtylyov)
- clean up SR-IOV resource handling by disabling VF decoding before
updating the corresponding resource structs (Gavin Shan)
- clean up DesignWare-based drivers by unifying quirks to update Class
Code and Interrupt Pin and related handling of write-protected
registers (Hou Zhiqiang)
- clean up by adding empty generic pcibios_align_resource() and
pcibios_fixup_bus() and removing empty arch-specific implementations
(Palmer Dabbelt)
- request exclusive reset control for several drivers to allow cleanup
elsewhere (Philipp Zabel)
- constify various structures (Arvind Yadav, Bhumika Goyal)
- convert from full_name() to %pOF (Rob Herring)
- remove unused variables from iProc, HiSi, Altera, Keystone (Shawn
Lin)
* tag 'pci-v4.14-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (170 commits)
PCI: xgene: Clean up whitespace
PCI: xgene: Define XGENE_PCI_EXP_CAP and use generic PCI_EXP_RTCTL offset
PCI: xgene: Fix platform_get_irq() error handling
PCI: xilinx-nwl: Fix platform_get_irq() error handling
PCI: rockchip: Fix platform_get_irq() error handling
PCI: altera: Fix platform_get_irq() error handling
PCI: spear13xx: Fix platform_get_irq() error handling
PCI: artpec6: Fix platform_get_irq() error handling
PCI: armada8k: Fix platform_get_irq() error handling
PCI: dra7xx: Fix platform_get_irq() error handling
PCI: exynos: Fix platform_get_irq() error handling
PCI: iproc: Clean up whitespace
PCI: iproc: Rename PCI_EXP_CAP to IPROC_PCI_EXP_CAP
PCI: iproc: Add 500ms delay during device shutdown
PCI: Fix typos and whitespace errors
PCI: Remove unused "res" variable from pci_resource_io()
PCI: Correct kernel-doc of pci_vpd_srdt_size(), pci_vpd_srdt_tag()
PCI/AER: Reformat AER register definitions
iommu/vt-d: Prevent VMD child devices from being remapping targets
x86/PCI: Use is_vmd() rather than relying on the domain number
...
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'arm/mediatek', 'arm/tegra', 'arm/qcom', 'arm/smmu', 'ppc/pamu', 'x86/vt-d', 'x86/amd', 's390' and 'core' into next
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Previously, we were invalidating context cache and IOTLB globally when
clearing one context entry. This is a tad too aggressive.
Invalidate the context cache and IOTLB for the interested device only.
Signed-off-by: Filippo Sironi <sironi@amazon.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: iommu@lists.linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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VMD child devices must use the VMD endpoint's ID as the requester. Because
of this, there needs to be a way to link the parent VMD endpoint's IOMMU
group and associated mappings to the VMD child devices such that attaching
and detaching child devices modify the endpoint's mappings, while
preventing early detaching on a singular device removal or unbinding.
The reassignment of individual VMD child devices devices to VMs is outside
the scope of VMD, but may be implemented in the future. For now it is best
to prevent any such attempts.
Prevent VMD child devices from returning an IOMMU, which prevents it from
exposing an iommu_group sysfs directory and allowing subsequent binding by
userspace-access drivers such as VFIO.
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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New kernels with debug show panic() from __phys_addr() checks. Avoid
calling virt_to_phys() when pasid_state_tbl pointer is null
To: Joerg Roedel <joro@8bytes.org>
To: linux-kernel@vger.kernel.org>
Cc: iommu@lists.linux-foundation.org
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jacob Pan <jacob.jun.pan@intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Fixes: 2f26e0a9c9860 ('iommu/vt-d: Add basic SVM PASID support')
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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Remove the deferred flushing implementation in the Intel
VT-d driver and use the one from the common iova code
instead.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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The struct iommu_device has a 'struct device' embedded into
it, not as a pointer, but the whole struct. In the
conversion of the iommu drivers to use struct iommu_device
it was forgotten that the relase function for that struct
device simply calls kfree() on the pointer.
This frees memory that was never allocated and causes memory
corruption.
To fix this issue, use a pointer to struct device instead of
embedding the whole struct. This needs some updates in the
iommu sysfs code as well as the Intel VT-d and AMD IOMMU
driver.
Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Fixes: 39ab9555c241 ('iommu: Add sysfs bindings for struct iommu_device')
Cc: stable@vger.kernel.org # >= v4.11
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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When adding a large scatterlist entry that covers more than the L3
superpage size (1GB) but has an alignment such that we must use L2
superpages (2MB) , we give dma_pte_free_level() a range that causes it
to free the L3 pagetable we're about to populate. We fix this by telling
dma_pte_free_pagetable() about the pagetable level we're about to populate
to prevent freeing it.
For example, mapping a scatterlist with entry lengths 854MB and 1194MB
at IOVA 0xffff80000000 would, when processing the 2MB-aligned second
entry, cause pfn_to_dma_pte() to create a L3 directory to hold L2
superpages for the mapping at IOVA 0xffffc0000000. We would previously
call dma_pte_free_pagetable(domain, 0xffffc0000, 0xfffffffff), which
would free the L3 directory pfn_to_dma_pte() just created for IO PFN
0xffffc0000. Telling dma_pte_free_pagetable() to retain the L3
directories while using L2 superpages avoids the erroneous free.
Signed-off-by: David Dillow <dillow@google.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull IOMMU updates from Joerg Roedel:
"This update comes with:
- Support for lockless operation in the ARM io-pgtable code.
This is an important step to solve the scalability problems in the
common dma-iommu code for ARM
- Some Errata workarounds for ARM SMMU implemenations
- Rewrite of the deferred IO/TLB flush code in the AMD IOMMU driver.
The code suffered from very high flush rates, with the new
implementation the flush rate is down to ~1% of what it was before
- Support for amd_iommu=off when booting with kexec.
The problem here was that the IOMMU driver bailed out early without
disabling the iommu hardware, if it was enabled in the old kernel
- The Rockchip IOMMU driver is now available on ARM64
- Align the return value of the iommu_ops->device_group call-backs to
not miss error values
- Preempt-disable optimizations in the Intel VT-d and common IOVA
code to help Linux-RT
- Various other small cleanups and fixes"
* tag 'iommu-updates-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (60 commits)
iommu/vt-d: Constify intel_dma_ops
iommu: Warn once when device_group callback returns NULL
iommu/omap: Return ERR_PTR in device_group call-back
iommu: Return ERR_PTR() values from device_group call-backs
iommu/s390: Use iommu_group_get_for_dev() in s390_iommu_add_device()
iommu/vt-d: Don't disable preemption while accessing deferred_flush()
iommu/iova: Don't disable preempt around this_cpu_ptr()
iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #126
iommu/arm-smmu-v3: Enable ACPI based HiSilicon CMD_PREFETCH quirk(erratum 161010701)
iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #74
ACPI/IORT: Fixup SMMUv3 resource size for Cavium ThunderX2 SMMUv3 model
iommu/arm-smmu-v3, acpi: Add temporary Cavium SMMU-V3 IORT model number definitions
iommu/io-pgtable-arm: Use dma_wmb() instead of wmb() when publishing table
iommu/io-pgtable: depend on !GENERIC_ATOMIC64 when using COMPILE_TEST with LPAE
iommu/arm-smmu-v3: Remove io-pgtable spinlock
iommu/arm-smmu: Remove io-pgtable spinlock
iommu/io-pgtable-arm-v7s: Support lockless operation
iommu/io-pgtable-arm: Support lockless operation
iommu/io-pgtable: Introduce explicit coherency
iommu/io-pgtable-arm-v7s: Refactor split_blk_unmap
...
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Pull dma-mapping infrastructure from Christoph Hellwig:
"This is the first pull request for the new dma-mapping subsystem
In this new subsystem we'll try to properly maintain all the generic
code related to dma-mapping, and will further consolidate arch code
into common helpers.
This pull request contains:
- removal of the DMA_ERROR_CODE macro, replacing it with calls to
->mapping_error so that the dma_map_ops instances are more self
contained and can be shared across architectures (me)
- removal of the ->set_dma_mask method, which duplicates the
->dma_capable one in terms of functionality, but requires more
duplicate code.
- various updates for the coherent dma pool and related arm code
(Vladimir)
- various smaller cleanups (me)"
* tag 'dma-mapping-4.13' of git://git.infradead.org/users/hch/dma-mapping: (56 commits)
ARM: dma-mapping: Remove traces of NOMMU code
ARM: NOMMU: Set ARM_DMA_MEM_BUFFERABLE for M-class cpus
ARM: NOMMU: Introduce dma operations for noMMU
drivers: dma-mapping: allow dma_common_mmap() for NOMMU
drivers: dma-coherent: Introduce default DMA pool
drivers: dma-coherent: Account dma_pfn_offset when used with device tree
dma: Take into account dma_pfn_offset
dma-mapping: replace dmam_alloc_noncoherent with dmam_alloc_attrs
dma-mapping: remove dmam_free_noncoherent
crypto: qat - avoid an uninitialized variable warning
au1100fb: remove a bogus dma_free_nonconsistent call
MAINTAINERS: add entry for dma mapping helpers
powerpc: merge __dma_set_mask into dma_set_mask
dma-mapping: remove the set_dma_mask method
powerpc/cell: use the dma_supported method for ops switching
powerpc/cell: clean up fixed mapping dma_ops initialization
tile: remove dma_supported and mapping_error methods
xen-swiotlb: remove xen_swiotlb_set_dma_mask
arm: implement ->dma_supported instead of ->set_dma_mask
mips/loongson64: implement ->dma_supported instead of ->set_dma_mask
...
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And instead wire it up as method for all the dma_map_ops instances.
Note that this also means the arch specific check will be fully instead
of partially applied in the AMD iommu driver.
Signed-off-by: Christoph Hellwig <hch@lst.de>
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'arm/core', 'x86/vt-d', 'x86/amd', 's390' and 'core' into next
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Most dma_map_ops structures are never modified. Constify these
structures such that these can be write-protected.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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get_cpu() disables preemption and returns the current CPU number. The
CPU number is only used once while retrieving the address of the local's
CPU deferred_flush pointer.
We can instead use raw_cpu_ptr() while we remain preemptible. The worst
thing that can happen is that flush_unmaps_timeout() is invoked multiple
times: once by taskA after seeing HIGH_WATER_MARK and then preempted to
another CPU and then by taskB which saw HIGH_WATER_MARK on the same CPU
as taskA. It is also likely that ->size got from HIGH_WATER_MARK to 0
right after its read because another CPU invoked flush_unmaps_timeout()
for this CPU.
The access to flush_data is protected by a spinlock so even if we get
migrated to another CPU or preempted - the data structure is protected.
While at it, I marked deferred_flush static since I can't find a
reference to it outside of this file.
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: iommu@lists.linux-foundation.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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We do find_domain() in __get_valid_domain_for_dev(), while we do the
same thing in get_valid_domain_for_dev(). No need to do it twice.
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.
Adjust the system_state checks in dmar_parse_one_atsr() and
dmar_iommu_notify_scope_dev() to handle the extra states.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Joerg Roedel <joro@8bytes.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: iommu@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/20170516184735.712365947@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Ever since commit 091d42e43d ("iommu/vt-d: Copy translation tables from
old kernel") the kdump kernel copies the IOMMU context tables from the
previous kernel. Each device mappings will be destroyed once the driver
for the respective device takes over.
This unfortunately breaks the workflow of mapping and unmapping a new
context to the IOMMU. The mapping function assumes that either:
1) Unmapping did the proper IOMMU flushing and it only ever flush if the
IOMMU unit supports caching invalid entries.
2) The system just booted and the initialization code took care of
flushing all IOMMU caches.
This assumption is not true for the kdump kernel since the context
tables have been copied from the previous kernel and translations could
have been cached ever since. So make sure to flush the IOTLB as well
when we destroy these old copied mappings.
Cc: Joerg Roedel <joro@8bytes.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Anthony Liguori <aliguori@amazon.com>
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: stable@vger.kernel.org v4.2+
Fixes: 091d42e43d ("iommu/vt-d: Copy translation tables from old kernel")
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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'arm/smmu', 'arm/core', 'x86/vt-d', 'x86/amd' and 'core' into next
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IOMMU harms performance signficantly when we run very fast networking
workloads. It's 40GB networking doing XDP test. Software overhead is
almost unaware, but it's the IOTLB miss (based on our analysis) which
kills the performance. We observed the same performance issue even with
software passthrough (identity mapping), only the hardware passthrough
survives. The pps with iommu (with software passthrough) is only about
~30% of that without it. This is a limitation in hardware based on our
observation, so we'd like to disable the IOMMU force on, but we do want
to use TBOOT and we can sacrifice the DMA security bought by IOMMU. I
must admit I know nothing about TBOOT, but TBOOT guys (cc-ed) think not
eabling IOMMU is totally ok.
So introduce a new boot option to disable the force on. It's kind of
silly we need to run into intel_iommu_init even without force on, but we
need to disable TBOOT PMR registers. For system without the boot option,
nothing is changed.
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
|
|
When booting into a kexec kernel with intel_iommu=off, and
the previous kernel had intel_iommu=on, the IOMMU hardware
is still enabled and gets not disabled by the new kernel.
This causes the boot to fail because DMA is blocked by the
hardware. Disable the IOMMUs when we find it enabled in the
kexec kernel and boot with intel_iommu=off.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
|
|
The introduction of reserved regions has left a couple of rough edges
which we could do with sorting out sooner rather than later. Since we
are not yet addressing the potential dynamic aspect of software-managed
reservations and presenting them at arbitrary fixed addresses, it is
incongruous that we end up displaying hardware vs. software-managed MSI
regions to userspace differently, especially since ARM-based systems may
actually require one or the other, or even potentially both at once,
(which iommu-dma currently has no hope of dealing with at all). Let's
resolve the former user-visible inconsistency ASAP before the ABI has
been baked into a kernel release, in a way that also lays the groundwork
for the latter shortcoming to be addressed by follow-up patches.
For clarity, rename the software-managed type to IOMMU_RESV_SW_MSI, use
IOMMU_RESV_MSI to describe the hardware type, and document everything a
little bit. Since the x86 MSI remapping hardware falls squarely under
this meaning of IOMMU_RESV_MSI, apply that type to their regions as well,
so that we tell the same story to userspace across all platforms.
Secondly, as the various region types require quite different handling,
and it really makes little sense to ever try combining them, convert the
bitfield-esque #defines to a plain enum in the process before anyone
gets the wrong impression.
Fixes: d30ddcaa7b02 ("iommu: Add a new type field in iommu_resv_region")
Reviewed-by: Eric Auger <eric.auger@redhat.com>
CC: Alex Williamson <alex.williamson@redhat.com>
CC: David Woodhouse <dwmw2@infradead.org>
CC: kvm@vger.kernel.org
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
|
|
The function device_to_iommu() in the Intel VT-d driver
lacks a NULL-ptr check, resulting in this oops at boot on
some platforms:
BUG: unable to handle kernel NULL pointer dereference at 00000000000007ab
IP: [<ffffffff8132234a>] device_to_iommu+0x11a/0x1a0
PGD 0
[...]
Call Trace:
? find_or_alloc_domain.constprop.29+0x1a/0x300
? dw_dma_probe+0x561/0x580 [dw_dmac_core]
? __get_valid_domain_for_dev+0x39/0x120
? __intel_map_single+0x138/0x180
? intel_alloc_coherent+0xb6/0x120
? sst_hsw_dsp_init+0x173/0x420 [snd_soc_sst_haswell_pcm]
? mutex_lock+0x9/0x30
? kernfs_add_one+0xdb/0x130
? devres_add+0x19/0x60
? hsw_pcm_dev_probe+0x46/0xd0 [snd_soc_sst_haswell_pcm]
? platform_drv_probe+0x30/0x90
? driver_probe_device+0x1ed/0x2b0
? __driver_attach+0x8f/0xa0
? driver_probe_device+0x2b0/0x2b0
? bus_for_each_dev+0x55/0x90
? bus_add_driver+0x110/0x210
? 0xffffffffa11ea000
? driver_register+0x52/0xc0
? 0xffffffffa11ea000
? do_one_initcall+0x32/0x130
? free_vmap_area_noflush+0x37/0x70
? kmem_cache_alloc+0x88/0xd0
? do_init_module+0x51/0x1c4
? load_module+0x1ee9/0x2430
? show_taint+0x20/0x20
? kernel_read_file+0xfd/0x190
? SyS_finit_module+0xa3/0xb0
? do_syscall_64+0x4a/0xb0
? entry_SYSCALL64_slow_path+0x25/0x25
Code: 78 ff ff ff 4d 85 c0 74 ee 49 8b 5a 10 0f b6 9b e0 00 00 00 41 38 98 e0 00 00 00 77 da 0f b6 eb 49 39 a8 88 00 00 00 72 ce eb 8f <41> f6 82 ab 07 00 00 04 0f 85 76 ff ff ff 0f b6 4d 08 88 0e 49
RIP [<ffffffff8132234a>] device_to_iommu+0x11a/0x1a0
RSP <ffffc90001457a78>
CR2: 00000000000007ab
---[ end trace 16f974b6d58d0aad ]---
Add the missing pointer check.
Fixes: 1c387188c60f53b338c20eee32db055dfe022a9b ("iommu/vt-d: Fix IOMMU lookup for SR-IOV Virtual Functions")
Signed-off-by: Koos Vriezen <koos.vriezen@gmail.com>
Cc: stable@vger.kernel.org # 4.8.15+
Signed-off-by: Joerg Roedel <jroedel@suse.de>
|
|
The link between the iommu sysfs-device and the struct
intel_iommu is no longer stored as driver-data. Update the
code to use the new access method.
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Fixes: 39ab9555c241 ('iommu: Add sysfs bindings for struct iommu_device')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
|
|
The callers of the DMA alloc functions already provide the proper
context GFP flags. Make sure to pass them through to the CMA allocator,
to make the CMA compaction context aware.
Link: http://lkml.kernel.org/r/20170127172328.18574-3-l.stach@pengutronix.de
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Alexander Graf <agraf@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
'arm/mediatek', 'arm/core', 'x86/vt-d' and 'core' into next
|
|
This makes the interface more consistent with
iommu_device_sysfs_add/remove.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
|
|
There is currently support for iommu sysfs bindings, but
those need to be implemented in the IOMMU drivers. Add a
more generic version of this by adding a struct device to
struct iommu_device and use that for the sysfs bindings.
Also convert the AMD and Intel IOMMU driver to make use of
it.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
|
|
This struct represents one hardware iommu in the iommu core
code. For now it only has the iommu-ops associated with it,
but that will be extended soon.
The register/unregister interface is also added, as well as
making use of it in the Intel and AMD IOMMU drivers.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
|
|
dma_pte_free_level() recurses down the IOMMU page tables and frees
directory pages that are entirely contained in the given PFN range.
Unfortunately, it incorrectly calculates the starting address covered
by the PTE under consideration, which can lead to it clearing an entry
that is still in use.
This occurs if we have a scatterlist with an entry that has a length
greater than 1026 MB and is aligned to 2 MB for both the IOMMU and
physical addresses. For example, if __domain_mapping() is asked to map a
two-entry scatterlist with 2 MB and 1028 MB segments to PFN 0xffff80000,
it will ask if dma_pte_free_pagetable() is asked to PFNs from
0xffff80200 to 0xffffc05ff, it will also incorrectly clear the PFNs from
0xffff80000 to 0xffff801ff because of this issue. The current code will
set level_pfn to 0xffff80200, and 0xffff80200-0xffffc01ff fits inside
the range being cleared. Properly setting the level_pfn for the current
level under consideration catches that this PTE is outside of the range
being cleared.
This patch also changes the value passed into dma_pte_free_level() when
it recurses. This only affects the first PTE of the range being cleared,
and is handled by the existing code that ensures we start our cursor no
lower than start_pfn.
This was found when using dma_map_sg() to map large chunks of contiguous
memory, which immediatedly led to faults on the first access of the
erroneously-deleted mappings.
Fixes: 3269ee0bd668 ("intel-iommu: Fix leaks in pagetable freeing")
Reviewed-by: Benjamin Serebrin <serebrin@google.com>
Signed-off-by: David Dillow <dillow@google.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
|
|
The check to set identity map for tylersburg is done too late. It needs
to be done before the check for identity_map domain is done.
To: Joerg Roedel <joro@8bytes.org>
To: David Woodhouse <dwmw2@infradead.org>
Cc: iommu@lists.linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Cc: Ashok Raj <ashok.raj@intel.com>
Fixes: 86080ccc22 ("iommu/vt-d: Allocate si_domain in init_dmars()")
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Reported-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
|
|
This patch registers the [FEE0_0000h - FEF0_000h] 1MB MSI
range as a reserved region and RMRR regions as direct regions.
This will allow to report those reserved regions in the
iommu-group sysfs.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
|
|
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 <mika.kuoppala@linux.intel.com>
cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Tested-by: Mika Kuoppala <mika.kuoppala@intel.com>
Fixes: 2f26e0a9c9860 ('iommu/vt-d: Add basic SVM PASID support')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
|
|
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 <myron.stowe@gmail.com>
CC: Joseph Szczypek <jszczype@redhat.com>
CC: Don Brace <don.brace@microsemi.com>
CC: Baoquan He <bhe@redhat.com>
CC: Dave Young <dyoung@redhat.com>
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 <xlpang@redhat.com>
Tested-by: Don Brace <don.brace@microsemi.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull smp hotplug updates from Thomas Gleixner:
"This is the final round of converting the notifier mess to the state
machine. The removal of the notifiers and the related infrastructure
will happen around rc1, as there are conversions outstanding in other
trees.
The whole exercise removed about 2000 lines of code in total and in
course of the conversion several dozen bugs got fixed. The new
mechanism allows to test almost every hotplug step standalone, so
usage sites can exercise all transitions extensively.
There is more room for improvement, like integrating all the
pointlessly different architecture mechanisms of synchronizing,
setting cpus online etc into the core code"
* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
tracing/rb: Init the CPU mask on allocation
soc/fsl/qbman: Convert to hotplug state machine
soc/fsl/qbman: Convert to hotplug state machine
zram: Convert to hotplug state machine
KVM/PPC/Book3S HV: Convert to hotplug state machine
arm64/cpuinfo: Convert to hotplug state machine
arm64/cpuinfo: Make hotplug notifier symmetric
mm/compaction: Convert to hotplug state machine
iommu/vt-d: Convert to hotplug state machine
mm/zswap: Convert pool to hotplug state machine
mm/zswap: Convert dst-mem to hotplug state machine
mm/zsmalloc: Convert to hotplug state machine
mm/vmstat: Convert to hotplug state machine
mm/vmstat: Avoid on each online CPU loops
mm/vmstat: Drop get_online_cpus() from init_cpu_node_state/vmstat_cpu_dead()
tracing/rb: Convert to hotplug state machine
oprofile/nmi timer: Convert to hotplug state machine
net/iucv: Use explicit clean up labels in iucv_init()
x86/pci/amd-bus: Convert to hotplug state machine
x86/oprofile/nmi: Convert to hotplug state machine
...
|
|
Install the callbacks via the state machine.
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: iommu@lists.linux-foundation.org
Cc: rt@linutronix.de
Cc: David Woodhouse <dwmw2@infradead.org>
Link: http://lkml.kernel.org/r/20161126231350.10321-14-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
Pull IOMMU fixes from David Woodhouse:
"Two minor fixes.
The first fixes the assignment of SR-IOV virtual functions to the
correct IOMMU unit, and the second fixes the excessively large (and
physically contiguous) PASID tables used with SVM"
* git://git.infradead.org/intel-iommu:
iommu/vt-d: Fix PASID table allocation
iommu/vt-d: Fix IOMMU lookup for SR-IOV Virtual Functions
|
|
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 <jroedel@suse.de>
|
|
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.
Cc: stable@vger.kernel.org
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
|
|
When a domain is allocated through the get_valid_domain_for_dev
path, it will be context-mapped before the RMRR regions are
mapped in the page-table. This opens a short time window
where device-accesses to these regions fail and causing DMAR
faults.
Fix this by mapping the RMRR regions before the domain is
context-mapped.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
|
|
Split out the search for an already existing domain and the
context mapping of the device to the new domain.
This allows to map possible RMRR regions into the domain
before it is context mapped.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
|
|
The dma-mapping core and the implementations do not change the DMA
attributes passed by pointer. Thus the pointer can point to const data.
However the attributes do not have to be a bitfield. Instead unsigned
long will do fine:
1. This is just simpler. Both in terms of reading the code and setting
attributes. Instead of initializing local attributes on the stack
and passing pointer to it to dma_set_attr(), just set the bits.
2. It brings safeness and checking for const correctness because the
attributes are passed by value.
Semantic patches for this change (at least most of them):
virtual patch
virtual context
@r@
identifier f, attrs;
@@
f(...,
- struct dma_attrs *attrs
+ unsigned long attrs
, ...)
{
...
}
@@
identifier r.f;
@@
f(...,
- NULL
+ 0
)
and
// Options: --all-includes
virtual patch
virtual context
@r@
identifier f, attrs;
type t;
@@
t f(..., struct dma_attrs *attrs);
@@
identifier r.f;
@@
f(...,
- NULL
+ 0
)
Link: http://lkml.kernel.org/r/1468399300-5399-2-git-send-email-k.kozlowski@samsung.com
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no>
Acked-by: Mark Salter <msalter@redhat.com> [c6x]
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> [cris]
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> [drm]
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Acked-by: Joerg Roedel <jroedel@suse.de> [iommu]
Acked-by: Fabien Dessenne <fabien.dessenne@st.com> [bdisp]
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> [vb2-core]
Acked-by: David Vrabel <david.vrabel@citrix.com> [xen]
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [xen swiotlb]
Acked-by: Joerg Roedel <jroedel@suse.de> [iommu]
Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon]
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [s390]
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> [avr32]
Acked-by: Vineet Gupta <vgupta@synopsys.com> [arc]
Acked-by: Robin Murphy <robin.murphy@arm.com> [arm64 and dma-iommu]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull IOMMU updates from Joerg Roedel:
- big-endian support and preparation for defered probing for the Exynos
IOMMU driver
- simplifications in iommu-group id handling
- support for Mediatek generation one IOMMU hardware
- conversion of the AMD IOMMU driver to use the generic IOVA allocator.
This driver now also benefits from the recent scalability
improvements in the IOVA code.
- preparations to use generic DMA mapping code in the Rockchip IOMMU
driver
- device tree adaption and conversion to use generic page-table code
for the MSM IOMMU driver
- an iova_to_phys optimization in the ARM-SMMU driver to greatly
improve page-table teardown performance with VFIO
- various other small fixes and conversions
* tag 'iommu-updates-v4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (59 commits)
iommu/amd: Initialize dma-ops domains with 3-level page-table
iommu/amd: Update Alias-DTE in update_device_table()
iommu/vt-d: Return error code in domain_context_mapping_one()
iommu/amd: Use container_of to get dma_ops_domain
iommu/amd: Flush iova queue before releasing dma_ops_domain
iommu/amd: Handle IOMMU_DOMAIN_DMA in ops->domain_free call-back
iommu/amd: Use dev_data->domain in get_domain()
iommu/amd: Optimize map_sg and unmap_sg
iommu/amd: Introduce dir2prot() helper
iommu/amd: Implement timeout to flush unmap queues
iommu/amd: Implement flush queue
iommu/amd: Allow NULL pointer parameter for domain_flush_complete()
iommu/amd: Set up data structures for flush queue
iommu/amd: Remove align-parameter from __map_single()
iommu/amd: Remove other remains of old address allocator
iommu/amd: Make use of the generic IOVA allocator
iommu/amd: Remove special mapping code for dma_ops path
iommu/amd: Pass gfp-flags to iommu_map_page()
iommu/amd: Implement apply_dm_region call-back
iommu/amd: Create a list of reserved iova addresses
...
|
|
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 <torvalds@linux-foundation.org>
|
|
'arm/msm', 'arm/rockchip', 'arm/smmu' and 'core' into next
|
