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2018-07-27iommu/dma: Respect bus DMA limit for IOVAsRobin Murphy1-0/+3
Take the new bus limit into account (when present) for IOVA allocations, to accommodate those SoCs which integrate off-the-shelf IP blocks with narrower interconnects such that the link between a device output and an IOMMU input can truncate DMA addresses to even fewer bits than the native size of either block's interface would imply. Eventually it might make sense for the DMA core to apply this constraint up-front in dma_set_mask() and friends, but for now this seems like the least risky approach. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-03iommu/dma: Move PCI window region reservation back into dma specific path.Shameer Kolothum1-29/+25
This pretty much reverts commit 273df9635385 ("iommu/dma: Make PCI window reservation generic") by moving the PCI window region reservation back into the dma specific path so that these regions doesn't get exposed via the IOMMU API interface. With this change, the vfio interface will report only iommu specific reserved regions to the user space. Cc: Joerg Roedel <joro@8bytes.org> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Fixes: 273df9635385 ('iommu/dma: Make PCI window reservation generic') Signed-off-by: Joerg Roedel <jroedel@suse.de>
2018-02-14iommu/dma: Add HW MSI(GICv3 ITS) address regions reservationShameer Kolothum1-1/+7
Modified iommu_dma_get_resv_regions() to include GICv3 ITS region on ACPI based ARM platfiorms which may require HW MSI reservations. Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-10-12iommu/iova: Make rcache flush optional on IOVA allocation failureTomasz Nowicki1-2/+4
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>
2017-09-27iommu/iova: Make dma_32bit_pfn implicitZhen Lei1-17/+1
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>
2017-07-12Merge tag 'iommu-updates-v4.13' of ↵Linus Torvalds1-1/+1
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 ...
2017-06-28Merge branches 'iommu/fixes', 'arm/rockchip', 'arm/renesas', 'arm/smmu', ↵Joerg Roedel1-1/+1
'arm/core', 'x86/vt-d', 'x86/amd', 's390' and 'core' into next
2017-06-20iommu/dma: don't rely on DMA_ERROR_CODEChristoph Hellwig1-8/+10
DMA_ERROR_CODE is not a public API and will go away soon. dma dma-iommu driver already implements a proper ->mapping_error method, so it's only using the value internally. Add a new local define using the value that arm64 which is the only current user of dma-iommu. Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-17iommu/iova: Sort out rbtree limit_pfn handlingRobin Murphy1-1/+1
When walking the rbtree, the fact that iovad->start_pfn and limit_pfn are both inclusive limits creates an ambiguity once limit_pfn reaches the bottom of the address space and they overlap. Commit 5016bdb796b3 ("iommu/iova: Fix underflow bug in __alloc_and_insert_iova_range") fixed the worst side-effect of this, that of underflow wraparound leading to bogus allocations, but the remaining fallout is that any attempt to allocate start_pfn itself erroneously fails. The cleanest way to resolve the ambiguity is to simply make limit_pfn an exclusive limit when inside the guts of the rbtree. Since we're working with PFNs, representing one past the top of the address space is always possible without fear of overflow, and elsewhere it just makes life a little more straightforward. Reported-by: Aaron Sierra <asierra@xes-inc.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-05-17iommu/dma: Don't touch invalid iova_domain membersRobin Murphy1-5/+8
When __iommu_dma_map() and iommu_dma_free_iova() are called from iommu_dma_get_msi_page(), various iova_*() helpers are still invoked in the process, whcih is unwise since they access a different member of the union (the iova_domain) from that which was last written, and there's no guarantee that sensible values will result anyway. CLean up the code paths that are valid for an MSI cookie to ensure we only do iova_domain-specific things when we're actually dealing with one. Fixes: a44e6657585b ("iommu/dma: Clean up MSI IOVA allocation") Reported-by: Nate Watterson <nwatters@codeaurora.org> Tested-by: Shanker Donthineni <shankerd@codeaurora.org> Tested-by: Bharat Bhushan <bharat.bhushan@nxp.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-04-03iommu/dma: Plumb in the per-CPU IOVA cachesRobin Murphy1-20/+17
With IOVA allocation suitably tidied up, we are finally free to opt in to the per-CPU caching mechanism. The caching alone can provide a modest improvement over walking the rbtree for weedier systems (iperf3 shows ~10% more ethernet throughput on an ARM Juno r1 constrained to a single 650MHz Cortex-A53), but the real gain will be in sidestepping the rbtree lock contention which larger ARM-based systems with lots of parallel I/O are starting to feel the pain of. Reviewed-by: Nate Watterson <nwatters@codeaurora.org> Tested-by: Nate Watterson <nwatters@codeaurora.org> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-04-03iommu/dma: Clean up MSI IOVA allocationRobin Murphy1-33/+25
Now that allocation is suitably abstracted, our private alloc/free helpers can drive the trivial MSI cookie allocator directly as well, which lets us clean up its exposed guts from iommu_dma_map_msi_msg() and simplify things quite a bit. Reviewed-by: Nate Watterson <nwatters@codeaurora.org> Tested-by: Nate Watterson <nwatters@codeaurora.org> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-04-03iommu/dma: Convert to address-based allocationRobin Murphy1-52/+67
In preparation for some IOVA allocation improvements, clean up all the explicit struct iova usage such that all our mapping, unmapping and cleanup paths deal exclusively with addresses rather than implementation details. In the process, a few of the things we're touching get renamed for the sake of internal consistency. Reviewed-by: Nate Watterson <nwatters@codeaurora.org> Tested-by: Nate Watterson <nwatters@codeaurora.org> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-03-22iommu/dma: Make PCI window reservation genericRobin Murphy1-10/+28
Now that we're applying the IOMMU API reserved regions to our IOVA domains, we shouldn't need to privately special-case PCI windows, or indeed anything else which isn't specific to our iommu-dma layer. However, since those aren't IOMMU-specific either, rather than start duplicating code into IOMMU drivers let's transform the existing function into an iommu_get_resv_regions() helper that they can share. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-03-22iommu/dma: Handle IOMMU API reserved regionsRobin Murphy1-7/+69
Now that it's simple to discover the necessary reservations for a given device/IOMMU combination, let's wire up the appropriate handling. Basic reserved regions and direct-mapped regions we simply have to carve out of IOVA space (the IOMMU core having already mapped the latter before attaching the device). For hardware MSI regions, we also pre-populate the cookie with matching msi_pages. That way, irqchip drivers which normally assume MSIs to require mapping at the IOMMU can keep working without having to special-case their iommu_dma_map_msi_msg() hook, or indeed be aware at all of quirks preventing the IOMMU from translating certain addresses. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-03-22iommu/dma: Don't reserve PCI I/O windowsRobin Murphy1-2/+1
Even if a host controller's CPU-side MMIO windows into PCI I/O space do happen to leak into PCI memory space such that it might treat them as peer addresses, trying to reserve the corresponding I/O space addresses doesn't do anything to help solve that problem. Stop doing a silly thing. Fixes: fade1ec055dc ("iommu/dma: Avoid PCI host bridge windows") Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-02-06iommu/dma: Remove bogus dma_supported() implementationRobin Murphy1-10/+0
Back when this was first written, dma_supported() was somewhat of a murky mess, with subtly different interpretations being relied upon in various places. The "does device X support DMA to address range Y?" uses assuming Y to be physical addresses, which motivated the current iommu_dma_supported() implementation and are alluded to in the comment therein, have since been cleaned up, leaving only the far less ambiguous "can device X drive address bits Y" usage internal to DMA API mask setting. As such, there is no reason to keep a slightly misleading callback which does nothing but duplicate the current default behaviour; we already constrain IOVA allocations to the iommu_domain aperture where necessary, so let's leave DMA mask business to architecture-specific code where it belongs. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-01-30iommu/dma: Implement PCI allocation optimisationRobin Murphy1-6/+15
Whilst PCI devices may have 64-bit DMA masks, they still benefit from using 32-bit addresses wherever possible in order to avoid DAC (PCI) or longer address packets (PCIe), which may incur a performance overhead. Implement the same optimisation as other allocators by trying to get a 32-bit address first, only falling back to the full mask if that fails. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-01-30iommu/dma: Stop getting dma_32bit_pfn wrongRobin Murphy1-5/+18
iommu_dma_init_domain() was originally written under the misconception that dma_32bit_pfn represented some sort of size limit for IOVA domains. Since the truth is almost the exact opposite of that, rework the logic and comments to reflect its real purpose of optimising lookups when allocating from a subset of the available 64-bit space. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-01-30Merge branch 'iommu/iommu-priv' of ↵Joerg Roedel1-3/+9
git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into arm/core
2017-01-23iommu/dma: Allow MSI-only cookiesRobin Murphy1-23/+96
IOMMU domain users such as VFIO face a similar problem to DMA API ops with regard to mapping MSI messages in systems where the MSI write is subject to IOMMU translation. With the relevant infrastructure now in place for managed DMA domains, it's actually really simple for other users to piggyback off that and reap the benefits without giving up their own IOVA management, and without having to reinvent their own wheel in the MSI layer. Allow such users to opt into automatic MSI remapping by dedicating a region of their IOVA space to a managed cookie, and extend the mapping routine to implement a trivial linear allocator in such cases, to avoid the needless overhead of a full-blown IOVA domain. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Tested-by: Tomasz Nowicki <tomasz.nowicki@caviumnetworks.com> Tested-by: Bharat Bhushan <bharat.bhushan@nxp.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-19arm64/dma-mapping: Implement DMA_ATTR_PRIVILEGEDMitchel Humpherys1-3/+9
The newly added DMA_ATTR_PRIVILEGED is useful for creating mappings that are only accessible to privileged DMA engines. Implement it in dma-iommu.c so that the ARM64 DMA IOMMU mapper can make use of it. Reviewed-by: Robin Murphy <robin.murphy@arm.com> Tested-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-11-14iommu/dma: Implement dma_{map,unmap}_resource()Robin Murphy1-3/+21
With the new dma_{map,unmap}_resource() functions added to the DMA API for the benefit of cases like slave DMA, add suitable implementations to the arsenal of our generic layer. Since cache maintenance should not be a concern, these can both be standalone callback implementations without the need for arch code wrappers. CC: Joerg Roedel <joro@8bytes.org> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2016-09-16iommu/dma: Avoid PCI host bridge windowsRobin Murphy1-1/+24
With our DMA ops enabled for PCI devices, we should avoid allocating IOVAs which a host bridge might misinterpret as peer-to-peer DMA and lead to faults, corruption or other badness. To be safe, punch out holes for all of the relevant host bridge's windows when initialising a DMA domain for a PCI device. CC: Marek Szyprowski <m.szyprowski@samsung.com> CC: Inki Dae <inki.dae@samsung.com> Reported-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-16iommu/dma: Add support for mapping MSIsRobin Murphy1-15/+121
When an MSI doorbell is located downstream of an IOMMU, attaching devices to a DMA ops domain and switching on translation leads to a rude shock when their attempt to write to the physical address returned by the irqchip driver faults (or worse, writes into some already-mapped buffer) and no interrupt is forthcoming. Address this by adding a hook for relevant irqchip drivers to call from their compose_msi_msg() callback, to swizzle the physical address with an appropriatly-mapped IOVA for any device attached to one of our DMA ops domains. Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-10iommu/dma: Respect IOMMU aperture when allocatingRobin Murphy1-4/+7
Where a device driver has set a 64-bit DMA mask to indicate the absence of addressing limitations, we still need to ensure that we don't allocate IOVAs beyond the actual input size of the IOMMU. The reported aperture is the most reliable way we have of inferring that input address size, so use that to enforce a hard upper limit where available. Fixes: 0db2e5d18f76 ("iommu: Implement common IOMMU ops for DMA mapping") Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2016-08-09iommu/dma: Don't put uninitialised IOVA domainsRobin Murphy1-1/+2
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") Cc: stable@vger.kernel.org Reported-by: Nate Watterson <nwatters@codeaurora.org> Reviewed-by: Nate Watterson <nwatters@codeaurora.org> Tested-by: Nate Watterson <nwatters@codeaurora.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2016-08-04dma-mapping: use unsigned long for dma_attrsKrzysztof Kozlowski1-4/+4
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>
2016-05-09iommu/dma: Finish optimising higher-order allocationsRobin Murphy1-21/+39
Now that we know exactly which page sizes our caller wants to use in the given domain, we can restrict higher-order allocation attempts to just those sizes, if any, and avoid wasting any time or effort on other sizes which offer no benefit. In the same vein, this also lets us accommodate a minimum order greater than 0 for special cases. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Tested-by: Yong Wu <yong.wu@mediatek.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2016-05-09iommu: Allow selecting page sizes per domainRobin Murphy1-1/+1
Many IOMMUs support multiple page table formats, meaning that any given domain may only support a subset of the hardware page sizes presented in iommu_ops->pgsize_bitmap. There are also certain use-cases where the creator of a domain may want to control which page sizes are used, for example to force the use of hugepage mappings to reduce pagetable walk depth. To this end, add a per-domain pgsize_bitmap to represent the subset of page sizes actually in use, to make it possible for domains with different requirements to coexist. Signed-off-by: Will Deacon <will.deacon@arm.com> [rm: hijacked and rebased original patch with new commit message] Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2016-05-09iommu/dma: Implement scatterlist segment mergingRobin Murphy1-23/+61
Stop wasting IOVA space by over-aligning scatterlist segments for a theoretical worst-case segment boundary mask, and instead take the real limits into account to merge consecutive segments wherever appropriate, so our callers can benefit from getting back nicely simplified lists. This also represents the last piece of functionality wanted by users of the current arch/arm implementation, thus brings us a small step closer to converting that over to the common code. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2016-04-05iommu/dma: Restore scatterlist offsets correctlyRobin Murphy1-2/+2
With the change to stashing just the IOVA-page-aligned remainder of the CPU-page offset rather than the whole thing, the failure path in __invalidate_sg() also needs tweaking to account for that in the case of differing page sizes where the two offsets may not be equivalent. Similarly in __finalise_sg(), lest the architecture-specific wrappers later get the wrong address for cache maintenance on sync or unmap. Fixes: 164afb1d85b8 ("iommu/dma: Use correct offset in map_sg") Reported-by: Magnus Damm <damm+renesas@opensource.se> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Cc: stable@ver.kernel.org # v4.4+ Signed-off-by: Joerg Roedel <jroedel@suse.de>
2016-01-07iommu/dma: Use correct offset in map_sgRobin Murphy1-1/+1
When mapping a non-page-aligned scatterlist entry, we copy the original offset to the output DMA address before aligning it to hand off to iommu_map_sg(), then later adding the IOVA page address portion to get the final mapped address. However, when the IOVA page size is smaller than the CPU page size, it is the offset within the IOVA page we want, not that within the CPU page, which can easily be larger than an IOVA page and thus result in an incorrect final address. Fix the bug by taking only the IOVA-aligned part of the offset as the basis of the DMA address, not the whole thing. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2015-12-28iommu/dma: Avoid unlikely high-order allocationsRobin Murphy1-2/+4
Doug reports that the equivalent page allocator on 32-bit ARM exhibits particularly pathalogical behaviour under memory pressure when fragmentation is high, where allocating a 4MB buffer takes tens of seconds and the number of calls to alloc_pages() is over 9000![1] We can drastically improve that situation without losing the other benefits of high-order allocations when they would succeed, by assuming memory pressure is relatively constant over the course of an allocation, and not retrying allocations at orders we know to have failed before. This way, the best-case behaviour remains unchanged, and in the worst case we should see at most a dozen or so (MAX_ORDER - 1) failed attempts before falling back to single pages for the remainder of the buffer. [1]:http://lists.infradead.org/pipermail/linux-arm-kernel/2015-December/394660.html Reported-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2015-12-28iommu/dma: Add some missing #includesRobin Murphy1-0/+3
dma-iommu.c was naughtily relying on an implicit transitive #include of linux/vmalloc.h, which is apparently not present on some architectures. Add that, plus a couple more headers for other functions which are used similarly. Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
2015-10-15iommu: Implement common IOMMU ops for DMA mappingRobin Murphy1-0/+524
Taking inspiration from the existing arch/arm code, break out some generic functions to interface the DMA-API to the IOMMU-API. This will do the bulk of the heavy lifting for IOMMU-backed dma-mapping. Since associating an IOVA allocator with an IOMMU domain is a fairly common need, rather than introduce yet another private structure just to do this for ourselves, extend the top-level struct iommu_domain with the notion. A simple opaque cookie allows reuse by other IOMMU API users with their various different incompatible allocator types. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>