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2020-11-03iommu: Fix a check in iommu_check_bind_data()Dan Carpenter
The "data->flags" variable is a u64 so if one of the high 32 bits is set the original code will allow it, but it should be rejected. The fix is to declare "mask" as a u64 instead of a u32. Fixes: d90573812eea ("iommu/uapi: Handle data and argsz filled by users") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/20201103101623.GA1127762@mwanda Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-11-03iommu/vt-d: Fix a bug for PDP check in prq_event_threadLiu, Yi L
In prq_event_thread(), the QI_PGRP_PDP is wrongly set by 'req->pasid_present' which should be replaced to 'req->priv_data_present'. Fixes: 5b438f4ba315 ("iommu/vt-d: Support page request in scalable mode") Signed-off-by: Liu, Yi L <yi.l.liu@intel.com> Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com> Acked-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/1604025444-6954-3-git-send-email-yi.y.sun@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-11-03iommu/vt-d: Fix sid not set issue in intel_svm_bind_gpasid()Liu Yi L
Should get correct sid and set it into sdev. Because we execute 'sdev->sid != req->rid' in the loop of prq_event_thread(). Fixes: eb8d93ea3c1d ("iommu/vt-d: Report page request faults for guest SVA") Signed-off-by: Liu Yi L <yi.l.liu@intel.com> Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com> Acked-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/1604025444-6954-2-git-send-email-yi.y.sun@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-11-03iommu/vt-d: Fix kernel NULL pointer dereference in find_domain()Lu Baolu
If calling find_domain() for a device which hasn't been probed by the iommu core, below kernel NULL pointer dereference issue happens. [ 362.736947] BUG: kernel NULL pointer dereference, address: 0000000000000038 [ 362.743953] #PF: supervisor read access in kernel mode [ 362.749115] #PF: error_code(0x0000) - not-present page [ 362.754278] PGD 0 P4D 0 [ 362.756843] Oops: 0000 [#1] SMP NOPTI [ 362.760528] CPU: 0 PID: 844 Comm: cat Not tainted 5.9.0-rc4-intel-next+ #1 [ 362.767428] Hardware name: Intel Corporation Ice Lake Client Platform/IceLake U DDR4 SODIMM PD RVP TLC, BIOS ICLSFWR1.R00.3384.A02.1909200816 09/20/2019 [ 362.781109] RIP: 0010:find_domain+0xd/0x40 [ 362.785234] Code: 48 81 fb 60 28 d9 b2 75 de 5b 41 5c 41 5d 5d c3 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 8b 87 e0 02 00 00 55 <48> 8b 40 38 48 89 e5 48 83 f8 fe 0f 94 c1 48 85 ff 0f 94 c2 08 d1 [ 362.804041] RSP: 0018:ffffb09cc1f0bd38 EFLAGS: 00010046 [ 362.809292] RAX: 0000000000000000 RBX: ffff905b98e4fac8 RCX: 0000000000000000 [ 362.816452] RDX: 0000000000000001 RSI: ffff905b98e4fac8 RDI: ffff905b9ccd40d0 [ 362.823617] RBP: ffffb09cc1f0bda0 R08: ffffb09cc1f0bd48 R09: 000000000000000f [ 362.830778] R10: ffffffffb266c080 R11: ffff905b9042602d R12: ffff905b98e4fac8 [ 362.837944] R13: ffffb09cc1f0bd48 R14: ffff905b9ccd40d0 R15: ffff905b98e4fac8 [ 362.845108] FS: 00007f8485460740(0000) GS:ffff905b9fc00000(0000) knlGS:0000000000000000 [ 362.853227] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 362.858996] CR2: 0000000000000038 CR3: 00000004627a6003 CR4: 0000000000770ef0 [ 362.866161] PKRU: fffffffc [ 362.868890] Call Trace: [ 362.871363] ? show_device_domain_translation+0x32/0x100 [ 362.876700] ? bind_store+0x110/0x110 [ 362.880387] ? klist_next+0x91/0x120 [ 362.883987] ? domain_translation_struct_show+0x50/0x50 [ 362.889237] bus_for_each_dev+0x79/0xc0 [ 362.893121] domain_translation_struct_show+0x36/0x50 [ 362.898204] seq_read+0x135/0x410 [ 362.901545] ? handle_mm_fault+0xeb8/0x1750 [ 362.905755] full_proxy_read+0x5c/0x90 [ 362.909526] vfs_read+0xa6/0x190 [ 362.912782] ksys_read+0x61/0xe0 [ 362.916037] __x64_sys_read+0x1a/0x20 [ 362.919725] do_syscall_64+0x37/0x80 [ 362.923329] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 362.928405] RIP: 0033:0x7f84855c5e95 Filter out those devices to avoid such error. Fixes: e2726daea583d ("iommu/vt-d: debugfs: Add support to show page table internals") Reported-and-tested-by: Xu Pengfei <pengfei.xu@intel.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Cc: stable@vger.kernel.org#v5.6+ Link: https://lore.kernel.org/r/20201028070725.24979-1-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-11-03iommu/amd: Increase interrupt remapping table limit to 512 entriesSuravee Suthikulpanit
Certain device drivers allocate IO queues on a per-cpu basis. On AMD EPYC platform, which can support up-to 256 cpu threads, this can exceed the current MAX_IRQ_PER_TABLE limit of 256, and result in the error message: AMD-Vi: Failed to allocate IRTE This has been observed with certain NVME devices. AMD IOMMU hardware can actually support upto 512 interrupt remapping table entries. Therefore, update the driver to match the hardware limit. Please note that this also increases the size of interrupt remapping table to 8KB per device when using the 128-bit IRTE format. Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Link: https://lore.kernel.org/r/20201015025002.87997-1-suravee.suthikulpanit@amd.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-10-20Merge tag 'iommu-fix-v5.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu Pull iommu fix from Joerg Roedel: "Fix a build regression with !CONFIG_IOMMU_API" * tag 'iommu-fix-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: iommu/vt-d: Don't dereference iommu_device if IOMMU_API is not built
2020-10-19iommu/vt-d: Don't dereference iommu_device if IOMMU_API is not builtBartosz Golaszewski
Since commit c40aaaac1018 ("iommu/vt-d: Gracefully handle DMAR units with no supported address widths") dmar.c needs struct iommu_device to be selected. We can drop this dependency by not dereferencing struct iommu_device if IOMMU_API is not selected and by reusing the information stored in iommu->drhd->ignored instead. This fixes the following build error when IOMMU_API is not selected: drivers/iommu/intel/dmar.c: In function ‘free_iommu’: drivers/iommu/intel/dmar.c:1139:41: error: ‘struct iommu_device’ has no member named ‘ops’ 1139 | if (intel_iommu_enabled && iommu->iommu.ops) { ^ Fixes: c40aaaac1018 ("iommu/vt-d: Gracefully handle DMAR units with no supported address widths") Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Acked-by: Lu Baolu <baolu.lu@linux.intel.com> Acked-by: David Woodhouse <dwmw@amazon.co.uk> Link: https://lore.kernel.org/r/20201013073055.11262-1-brgl@bgdev.pl Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-10-15Merge tag 'dma-mapping-5.10' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds
Pull dma-mapping updates from Christoph Hellwig: - rework the non-coherent DMA allocator - move private definitions out of <linux/dma-mapping.h> - lower CMA_ALIGNMENT (Paul Cercueil) - remove the omap1 dma address translation in favor of the common code - make dma-direct aware of multiple dma offset ranges (Jim Quinlan) - support per-node DMA CMA areas (Barry Song) - increase the default seg boundary limit (Nicolin Chen) - misc fixes (Robin Murphy, Thomas Tai, Xu Wang) - various cleanups * tag 'dma-mapping-5.10' of git://git.infradead.org/users/hch/dma-mapping: (63 commits) ARM/ixp4xx: add a missing include of dma-map-ops.h dma-direct: simplify the DMA_ATTR_NO_KERNEL_MAPPING handling dma-direct: factor out a dma_direct_alloc_from_pool helper dma-direct check for highmem pages in dma_direct_alloc_pages dma-mapping: merge <linux/dma-noncoherent.h> into <linux/dma-map-ops.h> dma-mapping: move large parts of <linux/dma-direct.h> to kernel/dma dma-mapping: move dma-debug.h to kernel/dma/ dma-mapping: remove <asm/dma-contiguous.h> dma-mapping: merge <linux/dma-contiguous.h> into <linux/dma-map-ops.h> dma-contiguous: remove dma_contiguous_set_default dma-contiguous: remove dev_set_cma_area dma-contiguous: remove dma_declare_contiguous dma-mapping: split <linux/dma-mapping.h> cma: decrease CMA_ALIGNMENT lower limit to 2 firewire-ohci: use dma_alloc_pages dma-iommu: implement ->alloc_noncoherent dma-mapping: add new {alloc,free}_noncoherent dma_map_ops methods dma-mapping: add a new dma_alloc_pages API dma-mapping: remove dma_cache_sync 53c700: convert to dma_alloc_noncoherent ...
2020-10-14Merge tag 'iommu-updates-v5.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu Pull iommu updates from Joerg Roedel: - ARM-SMMU Updates from Will: - Continued SVM enablement, where page-table is shared with CPU - Groundwork to support integrated SMMU with Adreno GPU - Allow disabling of MSI-based polling on the kernel command-line - Minor driver fixes and cleanups (octal permissions, error messages, ...) - Secure Nested Paging Support for AMD IOMMU. The IOMMU will fault when a device tries DMA on memory owned by a guest. This needs new fault-types as well as a rewrite of the IOMMU memory semaphore for command completions. - Allow broken Intel IOMMUs (wrong address widths reported) to still be used for interrupt remapping. - IOMMU UAPI updates for supporting vSVA, where the IOMMU can access address spaces of processes running in a VM. - Support for the MT8167 IOMMU in the Mediatek IOMMU driver. - Device-tree updates for the Renesas driver to support r8a7742. - Several smaller fixes and cleanups all over the place. * tag 'iommu-updates-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (57 commits) iommu/vt-d: Gracefully handle DMAR units with no supported address widths iommu/vt-d: Check UAPI data processed by IOMMU core iommu/uapi: Handle data and argsz filled by users iommu/uapi: Rename uapi functions iommu/uapi: Use named union for user data iommu/uapi: Add argsz for user filled data docs: IOMMU user API iommu/qcom: add missing put_device() call in qcom_iommu_of_xlate() iommu/arm-smmu-v3: Add SVA device feature iommu/arm-smmu-v3: Check for SVA features iommu/arm-smmu-v3: Seize private ASID iommu/arm-smmu-v3: Share process page tables iommu/arm-smmu-v3: Move definitions to a header iommu/io-pgtable-arm: Move some definitions to a header iommu/arm-smmu-v3: Ensure queue is read after updating prod pointer iommu/amd: Re-purpose Exclusion range registers to support SNP CWWB iommu/amd: Add support for RMP_PAGE_FAULT and RMP_HW_ERR iommu/amd: Use 4K page for completion wait write-back semaphore iommu/tegra-smmu: Allow to group clients in same swgroup iommu/tegra-smmu: Fix iova->phys translation ...
2020-10-14Merge tag 'acpi-5.10-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI updates from Rafael Wysocki: "These add support for generic initiator-only proximity domains to the ACPI NUMA code and the architectures using it, clean up some non-ACPICA code referring to debug facilities from ACPICA, reduce the overhead related to accessing GPE registers, add a new DPTF (Dynamic Power and Thermal Framework) participant driver, update the ACPICA code in the kernel to upstream revision 20200925, add a new ACPI backlight whitelist entry, fix a few assorted issues and clean up some code. Specifics: - Add support for generic initiator-only proximity domains to the ACPI NUMA code and the architectures using it (Jonathan Cameron) - Clean up some non-ACPICA code referring to debug facilities from ACPICA that are not actually used in there (Hanjun Guo) - Add new DPTF driver for the PCH FIVR participant (Srinivas Pandruvada) - Reduce overhead related to accessing GPE registers in ACPICA and the OS interface layer and make it possible to access GPE registers using logical addresses if they are memory-mapped (Rafael Wysocki) - Update the ACPICA code in the kernel to upstream revision 20200925 including changes as follows: + Add predefined names from the SMBus sepcification (Bob Moore) + Update acpi_help UUID list (Bob Moore) + Return exceptions for string-to-integer conversions in iASL (Bob Moore) + Add a new "ALL <NameSeg>" debugger command (Bob Moore) + Add support for 64 bit risc-v compilation (Colin Ian King) + Do assorted cleanups (Bob Moore, Colin Ian King, Randy Dunlap) - Add new ACPI backlight whitelist entry for HP 635 Notebook (Alex Hung) - Move TPS68470 OpRegion driver to drivers/acpi/pmic/ and split out Kconfig and Makefile specific for ACPI PMIC (Andy Shevchenko) - Clean up the ACPI SoC driver for AMD SoCs (Hanjun Guo) - Add missing config_item_put() to fix refcount leak (Hanjun Guo) - Drop lefrover field from struct acpi_memory_device (Hanjun Guo) - Make the ACPI extlog driver check for RDMSR failures (Ben Hutchings) - Fix handling of lid state changes in the ACPI button driver when input device is closed (Dmitry Torokhov) - Fix several assorted build issues (Barnabás Pőcze, John Garry, Nathan Chancellor, Tian Tao) - Drop unused inline functions and reduce code duplication by using kobj_to_dev() in the NFIT parsing code (YueHaibing, Wang Qing) - Serialize tools/power/acpi Makefile (Thomas Renninger)" * tag 'acpi-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (64 commits) ACPICA: Update version to 20200925 Version 20200925 ACPICA: Remove unnecessary semicolon ACPICA: Debugger: Add a new command: "ALL <NameSeg>" ACPICA: iASL: Return exceptions for string-to-integer conversions ACPICA: acpi_help: Update UUID list ACPICA: Add predefined names found in the SMBus sepcification ACPICA: Tree-wide: fix various typos and spelling mistakes ACPICA: Drop the repeated word "an" in a comment ACPICA: Add support for 64 bit risc-v compilation ACPI: button: fix handling lid state changes when input device closed tools/power/acpi: Serialize Makefile ACPI: scan: Replace ACPI_DEBUG_PRINT() with pr_debug() ACPI: memhotplug: Remove 'state' from struct acpi_memory_device ACPI / extlog: Check for RDMSR failure ACPI: Make acpi_evaluate_dsm() prototype consistent docs: mm: numaperf.rst Add brief description for access class 1. node: Add access1 class to represent CPU to memory characteristics ACPI: HMAT: Fix handling of changes from ACPI 6.2 to ACPI 6.3 ACPI: Let ACPI know we support Generic Initiator Affinity Structures x86: Support Generic Initiator only proximity domains ...
2020-10-13Merge branch 'acpi-numa'Rafael J. Wysocki
* acpi-numa: docs: mm: numaperf.rst Add brief description for access class 1. node: Add access1 class to represent CPU to memory characteristics ACPI: HMAT: Fix handling of changes from ACPI 6.2 to ACPI 6.3 ACPI: Let ACPI know we support Generic Initiator Affinity Structures x86: Support Generic Initiator only proximity domains ACPI: Support Generic Initiator only domains ACPI / NUMA: Add stub function for pxm_to_node() irq-chip/gic-v3-its: Fix crash if ITS is in a proximity domain without processor or memory ACPI: Remove side effect of partly creating a node in acpi_get_node() ACPI: Rename acpi_map_pxm_to_online_node() to pxm_to_online_node() ACPI: Remove side effect of partly creating a node in acpi_map_pxm_to_online_node() ACPI: Do not create new NUMA domains from ACPI static tables that are not SRAT ACPI: Add out of bounds and numa_off protections to pxm_to_node()
2020-10-12Merge tag 'x86-irq-2020-10-12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 irq updates from Thomas Gleixner: "Surgery of the MSI interrupt handling to prepare the support of upcoming devices which require non-PCI based MSI handling: - Cleanup historical leftovers all over the place - Rework the code to utilize more core functionality - Wrap XEN PCI/MSI interrupts into an irqdomain to make irqdomain assignment to PCI devices possible. - Assign irqdomains to PCI devices at initialization time which allows to utilize the full functionality of hierarchical irqdomains. - Remove arch_.*_msi_irq() functions from X86 and utilize the irqdomain which is assigned to the device for interrupt management. - Make the arch_.*_msi_irq() support conditional on a config switch and let the last few users select it" * tag 'x86-irq-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) PCI: MSI: Fix Kconfig dependencies for PCI_MSI_ARCH_FALLBACKS x86/apic/msi: Unbreak DMAR and HPET MSI iommu/amd: Remove domain search for PCI/MSI iommu/vt-d: Remove domain search for PCI/MSI[X] x86/irq: Make most MSI ops XEN private x86/irq: Cleanup the arch_*_msi_irqs() leftovers PCI/MSI: Make arch_.*_msi_irq[s] fallbacks selectable x86/pci: Set default irq domain in pcibios_add_device() iommm/amd: Store irq domain in struct device iommm/vt-d: Store irq domain in struct device x86/xen: Wrap XEN MSI management into irqdomain irqdomain/msi: Allow to override msi_domain_alloc/free_irqs() x86/xen: Consolidate XEN-MSI init x86/xen: Rework MSI teardown x86/xen: Make xen_msi_init() static and rename it to xen_hvm_msi_init() PCI/MSI: Provide pci_dev_has_special_msi_domain() helper PCI_vmd_Mark_VMD_irqdomain_with_DOMAIN_BUS_VMD_MSI irqdomain/msi: Provide DOMAIN_BUS_VMD_MSI x86/irq: Initialize PCI/MSI domain at PCI init time x86/pci: Reducde #ifdeffery in PCI init code ...
2020-10-12Merge tag 'x86_pasid_for_5.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 PASID updates from Borislav Petkov: "Initial support for sharing virtual addresses between the CPU and devices which doesn't need pinning of pages for DMA anymore. Add support for the command submission to devices using new x86 instructions like ENQCMD{,S} and MOVDIR64B. In addition, add support for process address space identifiers (PASIDs) which are referenced by those command submission instructions along with the handling of the PASID state on context switch as another extended state. Work by Fenghua Yu, Ashok Raj, Yu-cheng Yu and Dave Jiang" * tag 'x86_pasid_for_5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/asm: Add an enqcmds() wrapper for the ENQCMDS instruction x86/asm: Carve out a generic movdir64b() helper for general usage x86/mmu: Allocate/free a PASID x86/cpufeatures: Mark ENQCMD as disabled when configured out mm: Add a pasid member to struct mm_struct x86/msr-index: Define an IA32_PASID MSR x86/fpu/xstate: Add supervisor PASID state for ENQCMD x86/cpufeatures: Enumerate ENQCMD and ENQCMDS instructions Documentation/x86: Add documentation for SVA (Shared Virtual Addressing) iommu/vt-d: Change flags type to unsigned int in binding mm drm, iommu: Change type of pasid to u32
2020-10-07Merge branches 'arm/allwinner', 'arm/mediatek', 'arm/renesas', 'arm/tegra', ↵Joerg Roedel
'arm/qcom', 'arm/smmu', 'ppc/pamu', 'x86/amd', 'x86/vt-d' and 'core' into next
2020-10-07iommu/vt-d: Gracefully handle DMAR units with no supported address widthsDavid Woodhouse
Instead of bailing out completely, such a unit can still be used for interrupt remapping. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/linux-iommu/549928db2de6532117f36c9c810373c14cf76f51.camel@infradead.org/ Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-10-06dma-mapping: merge <linux/dma-noncoherent.h> into <linux/dma-map-ops.h>Christoph Hellwig
Move more nitty gritty DMA implementation details into the common internal header. Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-10-06dma-mapping: merge <linux/dma-contiguous.h> into <linux/dma-map-ops.h>Christoph Hellwig
Merge dma-contiguous.h into dma-map-ops.h, after removing the comment describing the contiguous allocator into kernel/dma/contigous.c. Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-10-06dma-mapping: split <linux/dma-mapping.h>Christoph Hellwig
Split out all the bits that are purely for dma_map_ops implementations and related code into a new <linux/dma-map-ops.h> header so that they don't get pulled into all the drivers. That also means the architecture specific <asm/dma-mapping.h> is not pulled in by <linux/dma-mapping.h> any more, which leads to a missing includes that were pulled in by the x86 or arm versions in a few not overly portable drivers. Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-10-01iommu/vt-d: Fix lockdep splat in iommu_flush_dev_iotlb()Lu Baolu
Lock(&iommu->lock) without disabling irq causes lockdep warnings. [ 12.703950] ======================================================== [ 12.703962] WARNING: possible irq lock inversion dependency detected [ 12.703975] 5.9.0-rc6+ #659 Not tainted [ 12.703983] -------------------------------------------------------- [ 12.703995] systemd-udevd/284 just changed the state of lock: [ 12.704007] ffffffffbd6ff4d8 (device_domain_lock){..-.}-{2:2}, at: iommu_flush_dev_iotlb.part.57+0x2e/0x90 [ 12.704031] but this lock took another, SOFTIRQ-unsafe lock in the past: [ 12.704043] (&iommu->lock){+.+.}-{2:2} [ 12.704045] and interrupts could create inverse lock ordering between them. [ 12.704073] other info that might help us debug this: [ 12.704085] Possible interrupt unsafe locking scenario: [ 12.704097] CPU0 CPU1 [ 12.704106] ---- ---- [ 12.704115] lock(&iommu->lock); [ 12.704123] local_irq_disable(); [ 12.704134] lock(device_domain_lock); [ 12.704146] lock(&iommu->lock); [ 12.704158] <Interrupt> [ 12.704164] lock(device_domain_lock); [ 12.704174] *** DEADLOCK *** Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/20200927062428.13713-1-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-10-01iommu/vt-d: Check UAPI data processed by IOMMU coreJacob Pan
IOMMU generic layer already does sanity checks on UAPI data for version match and argsz range based on generic information. This patch adjusts the following data checking responsibilities: - removes the redundant version check from VT-d driver - removes the check for vendor specific data size - adds check for the use of reserved/undefined flags Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Link: https://lore.kernel.org/r/1601051567-54787-7-git-send-email-jacob.jun.pan@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-10-01iommu/uapi: Handle data and argsz filled by usersJacob Pan
IOMMU user APIs are responsible for processing user data. This patch changes the interface such that user pointers can be passed into IOMMU code directly. Separate kernel APIs without user pointers are introduced for in-kernel users of the UAPI functionality. IOMMU UAPI data has a user filled argsz field which indicates the data length of the structure. User data is not trusted, argsz must be validated based on the current kernel data size, mandatory data size, and feature flags. User data may also be extended, resulting in possible argsz increase. Backward compatibility is ensured based on size and flags (or the functional equivalent fields) checking. This patch adds sanity checks in the IOMMU layer. In addition to argsz, reserved/unused fields in padding, flags, and version are also checked. Details are documented in Documentation/userspace-api/iommu.rst Signed-off-by: Liu Yi L <yi.l.liu@intel.com> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Link: https://lore.kernel.org/r/1601051567-54787-6-git-send-email-jacob.jun.pan@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-10-01iommu/uapi: Rename uapi functionsJacob Pan
User APIs such as iommu_sva_unbind_gpasid() may also be used by the kernel. Since we introduced user pointer to the UAPI functions, in-kernel callers cannot share the same APIs. In-kernel callers are also trusted, there is no need to validate the data. We plan to have two flavors of the same API functions, one called through ioctls, carrying a user pointer and one called directly with valid IOMMU UAPI structs. To differentiate both, let's rename existing functions with an iommu_uapi_ prefix. Suggested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Link: https://lore.kernel.org/r/1601051567-54787-5-git-send-email-jacob.jun.pan@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-10-01iommu/uapi: Use named union for user dataJacob Pan
IOMMU UAPI data size is filled by the user space which must be validated by the kernel. To ensure backward compatibility, user data can only be extended by either re-purpose padding bytes or extend the variable sized union at the end. No size change is allowed before the union. Therefore, the minimum size is the offset of the union. To use offsetof() on the union, we must make it named. Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Link: https://lore.kernel.org/linux-iommu/20200611145518.0c2817d6@x1.home/ Link: https://lore.kernel.org/r/1601051567-54787-4-git-send-email-jacob.jun.pan@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-10-01iommu/amd: Fix the overwritten field in IVMD headerAdrian Huang
Commit 387caf0b759a ("iommu/amd: Treat per-device exclusion ranges as r/w unity-mapped regions") accidentally overwrites the 'flags' field in IVMD (struct ivmd_header) when the I/O virtualization memory definition is associated with the exclusion range entry. This leads to the corrupted IVMD table (incorrect checksum). The kdump kernel reports the invalid checksum: ACPI BIOS Warning (bug): Incorrect checksum in table [IVRS] - 0x5C, should be 0x60 (20200717/tbprint-177) AMD-Vi: [Firmware Bug]: IVRS invalid checksum Fix the above-mentioned issue by modifying the 'struct unity_map_entry' member instead of the IVMD header. Cleanup: The *exclusion_range* functions are not used anymore, so get rid of them. Fixes: 387caf0b759a ("iommu/amd: Treat per-device exclusion ranges as r/w unity-mapped regions") Reported-and-tested-by: Baoquan He <bhe@redhat.com> Signed-off-by: Adrian Huang <ahuang12@lenovo.com> Cc: Jerry Snitselaar <jsnitsel@redhat.com> Link: https://lore.kernel.org/r/20200926102602.19177-1-adrianhuang0701@gmail.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-09-29iommu/qcom: add missing put_device() call in qcom_iommu_of_xlate()Yu Kuai
if of_find_device_by_node() succeed, qcom_iommu_of_xlate() doesn't have a corresponding put_device(). Thus add put_device() to fix the exception handling for this function implementation. Fixes: 0ae349a0f33f ("iommu/qcom: Add qcom_iommu") Acked-by: Rob Clark <robdclark@gmail.com> Signed-off-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20200929014037.2436663-1-yukuai3@huawei.com Signed-off-by: Will Deacon <will@kernel.org>
2020-09-28iommu/arm-smmu-v3: Add SVA device featureJean-Philippe Brucker
Implement the IOMMU device feature callbacks to support the SVA feature. At the moment dev_has_feat() returns false since I/O Page Faults and BTM aren't yet implemented. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20200918101852.582559-12-jean-philippe@linaro.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-28iommu/arm-smmu-v3: Check for SVA featuresJean-Philippe Brucker
Aggregate all sanity-checks for sharing CPU page tables with the SMMU under a single ARM_SMMU_FEAT_SVA bit. For PCIe SVA, users also need to check FEAT_ATS and FEAT_PRI. For platform SVA, they will have to check FEAT_STALLS. Introduce ARM_SMMU_FEAT_BTM (Broadcast TLB Maintenance), but don't enable it at the moment. Since the entire VMID space is shared with the CPU, enabling DVM (by clearing SMMU_CR2.PTM) could result in over-invalidation and affect performance of stage-2 mappings. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20200918101852.582559-11-jean-philippe@linaro.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-28iommu/arm-smmu-v3: Seize private ASIDJean-Philippe Brucker
The SMMU has a single ASID space, the union of shared and private ASID sets. This means that the SMMU driver competes with the arch allocator for ASIDs. Shared ASIDs are those of Linux processes, allocated by the arch, and contribute in broadcast TLB maintenance. Private ASIDs are allocated by the SMMU driver and used for "classic" map/unmap DMA. They require command-queue TLB invalidations. When we pin down an mm_context and get an ASID that is already in use by the SMMU, it belongs to a private context. We used to simply abort the bind, but this is unfair to users that would be unable to bind a few seemingly random processes. Try to allocate a new private ASID for the context, and make the old ASID shared. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20200918101852.582559-10-jean-philippe@linaro.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-28iommu/arm-smmu-v3: Share process page tablesJean-Philippe Brucker
With Shared Virtual Addressing (SVA), we need to mirror CPU TTBR, TCR, MAIR and ASIDs in SMMU contexts. Each SMMU has a single ASID space split into two sets, shared and private. Shared ASIDs correspond to those obtained from the arch ASID allocator, and private ASIDs are used for "classic" map/unmap DMA. A possible conflict happens when trying to use a shared ASID that has already been allocated for private use by the SMMU driver. This will be addressed in a later patch by replacing the private ASID. At the moment we return -EBUSY. Each mm_struct shared with the SMMU will have a single context descriptor. Add a refcount to keep track of this. It will be protected by the global SVA lock. Introduce a new arm-smmu-v3-sva.c file and the CONFIG_ARM_SMMU_V3_SVA option to let users opt in SVA support. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20200918101852.582559-9-jean-philippe@linaro.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-28iommu/arm-smmu-v3: Move definitions to a headerJean-Philippe Brucker
Allow sharing structure definitions with the upcoming SVA support for Arm SMMUv3, by moving them to a separate header. We could surgically extract only what is needed but keeping all definitions in one place looks nicer. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Link: https://lore.kernel.org/r/20200918101852.582559-8-jean-philippe@linaro.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-28iommu/io-pgtable-arm: Move some definitions to a headerJean-Philippe Brucker
Extract some of the most generic TCR defines, so they can be reused by the page table sharing code. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200918101852.582559-6-jean-philippe@linaro.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-28iommu/arm-smmu-v3: Ensure queue is read after updating prod pointerZhou Wang
Reading the 'prod' MMIO register in order to determine whether or not there is valid data beyond 'cons' for a given queue does not provide sufficient dependency ordering, as the resulting access is address dependent only on 'cons' and can therefore be speculated ahead of time, potentially allowing stale data to be read by the CPU. Use readl() instead of readl_relaxed() when updating the shadow copy of the 'prod' pointer, so that all speculated memory reads from the corresponding queue can occur only from valid slots. Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com> Link: https://lore.kernel.org/r/1601281922-117296-1-git-send-email-wangzhou1@hisilicon.com [will: Use readl() instead of explicit barrier. Update 'cons' side to match.] Signed-off-by: Will Deacon <will@kernel.org>
2020-09-25dma-iommu: implement ->alloc_noncoherentChristoph Hellwig
Implement the alloc_noncoherent method to provide memory that is neither coherent not contiguous. Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-09-25dma-mapping: add a new dma_alloc_pages APIChristoph Hellwig
This API is the equivalent of alloc_pages, except that the returned memory is guaranteed to be DMA addressable by the passed in device. The implementation will also be used to provide a more sensible replacement for DMA_ATTR_NON_CONSISTENT flag. Additionally dma_alloc_noncoherent is switched over to use dma_alloc_pages as its backend. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> (MIPS part)
2020-09-25Merge branch 'master' of ↵Christoph Hellwig
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into dma-mapping-for-next Pull in the latest 5.9 tree for the commit to revert the V4L2_FLAG_MEMORY_NON_CONSISTENT uapi addition.
2020-09-24ACPI: Do not create new NUMA domains from ACPI static tables that are not SRATJonathan Cameron
Several ACPI static tables contain references to proximity domains. ACPI 6.3 has clarified that only entries in SRAT may define a new domain (sec 5.2.16). Those tables described in the ACPI spec have additional clarifying text. NFIT: Table 5-132, "Integer that represents the proximity domain to which the memory belongs. This number must match with corresponding entry in the SRAT table." HMAT: Table 5-145, "... This number must match with the corresponding entry in the SRAT table's processor affinity structure ... if the initiator is a processor, or the Generic Initiator Affinity Structure if the initiator is a generic initiator". IORT and DMAR are defined by external specifications. Intel Virtualization Technology for Directed I/O Rev 3.1 does not make any explicit statements, but the general SRAT statement above will still apply. https://software.intel.com/sites/default/files/managed/c5/15/vt-directed-io-spec.pdf IO Remapping Table, Platform Design Document rev D, also makes not explicit statement, but refers to ACPI SRAT table for more information and again the generic SRAT statement above applies. https://developer.arm.com/documentation/den0049/d/ In conclusion, any proximity domain specified in these tables, should be a reference to a proximity domain also found in SRAT, and they should not be able to instantiate a new domain. Hence we switch to pxm_to_node() which will only return existing nodes. Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Barry Song <song.bao.hua@hisilicon.com> Reviewed-by: Hanjun Guo <guohanjun@huawei.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-09-24iommu/amd: Re-purpose Exclusion range registers to support SNP CWWBSuravee Suthikulpanit
When the IOMMU SNP support bit is set in the IOMMU Extended Features register, hardware re-purposes the following registers: 1. IOMMU Exclusion Base register (MMIO offset 0020h) to Completion Wait Write-Back (CWWB) Base register 2. IOMMU Exclusion Range Limit (MMIO offset 0028h) to Completion Wait Write-Back (CWWB) Range Limit register and requires the IOMMU CWWB semaphore base and range to be programmed in the register offset 0020h and 0028h accordingly. Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Link: https://lore.kernel.org/r/20200923121347.25365-4-suravee.suthikulpanit@amd.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-09-24iommu/amd: Add support for RMP_PAGE_FAULT and RMP_HW_ERRSuravee Suthikulpanit
IOMMU SNP support introduces two new IOMMU events: * RMP Page Fault event * RMP Hardware Error event Hence, add reporting functions for these events. Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Link: https://lore.kernel.org/r/20200923121347.25365-3-suravee.suthikulpanit@amd.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-09-24iommu/amd: Use 4K page for completion wait write-back semaphoreSuravee Suthikulpanit
IOMMU SNP support requires the completion wait write-back semaphore to be implemented using a 4K-aligned page, where the page address is to be programmed into the newly introduced MMIO base/range registers. This new scheme uses a per-iommu atomic variable to store the current semaphore value, which is incremented for every completion wait command. Since this new scheme is also compatible with non-SNP mode, generalize the driver to use 4K page for completion-wait semaphore in both modes. Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Link: https://lore.kernel.org/r/20200923121347.25365-2-suravee.suthikulpanit@amd.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-09-24iommu/tegra-smmu: Allow to group clients in same swgroupNicolin Chen
There can be clients using the same swgroup in DT, for example i2c0 and i2c1. The current driver will add them to separate IOMMU groups, though it has implemented device_group() callback which is to group devices using different swgroups like DC and DCB. All clients having the same swgroup should be also added to the same IOMMU group so as to share an asid. Otherwise, the asid register may get overwritten every time a new device is attached. Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com> Acked-by: Thierry Reding <treding@nvidia.com> Link: https://lore.kernel.org/r/20200911071643.17212-4-nicoleotsuka@gmail.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-09-24iommu/tegra-smmu: Fix iova->phys translationNicolin Chen
IOVA might not be always 4KB aligned. So tegra_smmu_iova_to_phys function needs to add on the lower 12-bit offset from input iova. Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com> Acked-by: Thierry Reding <treding@nvidia.com> Link: https://lore.kernel.org/r/20200911071643.17212-3-nicoleotsuka@gmail.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-09-24iommu/tegra-smmu: Do not use PAGE_SHIFT and PAGE_MASKNicolin Chen
PAGE_SHIFT and PAGE_MASK are defined corresponding to the page size for CPU virtual addresses, which means PAGE_SHIFT could be a number other than 12, but tegra-smmu maintains fixed 4KB IOVA pages and has fixed [21:12] bit range for PTE entries. So this patch replaces all PAGE_SHIFT/PAGE_MASK references with the macros defined with SMMU_PTE_SHIFT. Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com> Acked-by: Thierry Reding <treding@nvidia.com> Link: https://lore.kernel.org/r/20200911071643.17212-2-nicoleotsuka@gmail.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-09-24iommu/vt-d: Use device numa domain if RHSA is missingLu Baolu
If there are multiple NUMA domains but the RHSA is missing in ACPI/DMAR table, we could default to the device NUMA domain as fall back. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Ashok Raj <ashok.raj@intel.com> Link: https://lore.kernel.org/r/20200904010303.2961-1-baolu.lu@linux.intel.com Link: https://lore.kernel.org/r/20200922060843.31546-2-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-09-24iommu/exynos: add missing put_device() call in exynos_iommu_of_xlate()Yu Kuai
if of_find_device_by_node() succeed, exynos_iommu_of_xlate() doesn't have a corresponding put_device(). Thus add put_device() to fix the exception handling for this function implementation. Fixes: aa759fd376fb ("iommu/exynos: Add callback for initializing devices from device tree") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://lore.kernel.org/r/20200918011335.909141-1-yukuai3@huawei.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2020-09-21iommu/arm-smmu: Constify some helpersRob Clark
Sprinkle a few `const`s where helpers don't need write access. Signed-off-by: Rob Clark <robdclark@chromium.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-09-21iommu/arm-smmu: Prepare for the adreno-smmu implementationJordan Crouse
Do a bit of prep work to add the upcoming adreno-smmu implementation. Add an hook to allow the implementation to choose which context banks to allocate. Move some of the common structs to arm-smmu.h in anticipation of them being used by the implementations and update some of the existing hooks to pass more information that the implementation will need. These modifications will be used by the upcoming Adreno SMMU implementation to identify the GPU device and properly configure it for pagetable switching. Co-developed-by: Rob Clark <robdclark@chromium.org> Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org> Signed-off-by: Rob Clark <robdclark@chromium.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-09-21iommu/arm-smmu: Add support for split pagetablesJordan Crouse
Enable TTBR1 for a context bank if IO_PGTABLE_QUIRK_ARM_TTBR1 is selected by the io-pgtable configuration. Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org> Signed-off-by: Rob Clark <robdclark@chromium.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-09-21iommu/arm-smmu: Pass io-pgtable config to implementation specific functionJordan Crouse
Construct the io-pgtable config before calling the implementation specific init_context function and pass it so the implementation specific function can get a chance to change it before the io-pgtable is created. Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org> Signed-off-by: Rob Clark <robdclark@chromium.org> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-09-21iommu/arm-smmu-v3: Fix endianness annotationsJean-Philippe Brucker
When building with C=1, sparse reports some issues regarding endianness annotations: arm-smmu-v3.c:221:26: warning: cast to restricted __le64 arm-smmu-v3.c:221:24: warning: incorrect type in assignment (different base types) arm-smmu-v3.c:221:24: expected restricted __le64 [usertype] arm-smmu-v3.c:221:24: got unsigned long long [usertype] arm-smmu-v3.c:229:20: warning: incorrect type in argument 1 (different base types) arm-smmu-v3.c:229:20: expected restricted __le64 [usertype] *[assigned] dst arm-smmu-v3.c:229:20: got unsigned long long [usertype] *ent arm-smmu-v3.c:229:25: warning: incorrect type in argument 2 (different base types) arm-smmu-v3.c:229:25: expected unsigned long long [usertype] *[assigned] src arm-smmu-v3.c:229:25: got restricted __le64 [usertype] * arm-smmu-v3.c:396:20: warning: incorrect type in argument 1 (different base types) arm-smmu-v3.c:396:20: expected restricted __le64 [usertype] *[assigned] dst arm-smmu-v3.c:396:20: got unsigned long long * arm-smmu-v3.c:396:25: warning: incorrect type in argument 2 (different base types) arm-smmu-v3.c:396:25: expected unsigned long long [usertype] *[assigned] src arm-smmu-v3.c:396:25: got restricted __le64 [usertype] * arm-smmu-v3.c:1349:32: warning: invalid assignment: |= arm-smmu-v3.c:1349:32: left side has type restricted __le64 arm-smmu-v3.c:1349:32: right side has type unsigned long arm-smmu-v3.c:1396:53: warning: incorrect type in argument 3 (different base types) arm-smmu-v3.c:1396:53: expected restricted __le64 [usertype] *dst arm-smmu-v3.c:1396:53: got unsigned long long [usertype] *strtab arm-smmu-v3.c:1424:39: warning: incorrect type in argument 1 (different base types) arm-smmu-v3.c:1424:39: expected unsigned long long [usertype] *[assigned] strtab arm-smmu-v3.c:1424:39: got restricted __le64 [usertype] *l2ptr While harmless, they are incorrect and could hide actual errors during development. Fix them. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/20200918141856.629722-1-jean-philippe@linaro.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-21iommu/io-pgtable-arm: Clean up faulty sanity checkRobin Murphy
Checking for a nonzero dma_pfn_offset was a quick shortcut to validate whether the DMA == phys assumption could hold at all. Checking for a non-NULL dma_range_map is not quite equivalent, since a map may be present to describe a limited DMA window even without an offset, and thus this check can now yield false positives. However, it only ever served to short-circuit going all the way through to __arm_lpae_alloc_pages(), failing the canonical test there, and having a bit more to clean up. As such, we can simply remove it without loss of correctness. Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>