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: NJean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20200918101852.582559-10-jean-philippe@linaro.orgSigned-off-by: NWill Deacon <will@kernel.org>

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: NJean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20200918101852.582559-9-jean-philippe@linaro.orgSigned-off-by: NWill Deacon <will@kernel.org>

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: NJean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: NEric Auger <eric.auger@redhat.com>
Reviewed-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20200918101852.582559-8-jean-philippe@linaro.orgSigned-off-by: NWill Deacon <will@kernel.org>

Extract some of the most generic TCR defines, so they can be reused by
the page table sharing code.
Signed-off-by: NJean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: NWill Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200918101852.582559-6-jean-philippe@linaro.orgSigned-off-by: NWill Deacon <will@kernel.org>

Merge branch 'for-next/svm' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux into for-joerg/arm-smmu/updates

Pull in core arm64 changes required to enable Shared Virtual Memory
(SVM) using SMMUv3. This brings us increasingly closer to being able to
share page-tables directly between user-space tasks running on the CPU
and their corresponding contexts on coherent devices performing DMA
through the SMMU.
Signed-off-by: NWill Deacon <will@kernel.org>

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: NZhou 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: NWill Deacon <will@kernel.org>

The SMMUv3 driver would like to read the MMFR0 PARANGE field in order to
share CPU page tables with devices. Allow the driver to be built as
module by exporting the read_sanitized_ftr_reg() cpufeature symbol.
Signed-off-by: NJean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20200918101852.582559-7-jean-philippe@linaro.orgSigned-off-by: NWill Deacon <will@kernel.org>

To enable address space sharing with the IOMMU, introduce
arm64_mm_context_get() and arm64_mm_context_put(), that pin down a
context and ensure that it will keep its ASID after a rollover. Export
the symbols to let the modular SMMUv3 driver use them.

Pinning is necessary because a device constantly needs a valid ASID,
unlike tasks that only require one when running. Without pinning, we would
need to notify the IOMMU when we're about to use a new ASID for a task,
and it would get complicated when a new task is assigned a shared ASID.
Consider the following scenario with no ASID pinned:

1. Task t1 is running on CPUx with shared ASID (gen=1, asid=1)
2. Task t2 is scheduled on CPUx, gets ASID (1, 2)
3. Task tn is scheduled on CPUy, a rollover occurs, tn gets ASID (2, 1)
   We would now have to immediately generate a new ASID for t1, notify
   the IOMMU, and finally enable task tn. We are holding the lock during
   all that time, since we can't afford having another CPU trigger a
   rollover. The IOMMU issues invalidation commands that can take tens of
   milliseconds.

It gets needlessly complicated. All we wanted to do was schedule task tn,
that has no business with the IOMMU. By letting the IOMMU pin tasks when
needed, we avoid stalling the slow path, and let the pinning fail when
we're out of shareable ASIDs.

After a rollover, the allocator expects at least one ASID to be available
in addition to the reserved ones (one per CPU). So (NR_ASIDS - NR_CPUS -
1) is the maximum number of ASIDs that can be shared with the IOMMU.
Signed-off-by: NJean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20200918101852.582559-5-jean-philippe@linaro.orgSigned-off-by: NWill Deacon <will@kernel.org>

Sprinkle a few `const`s where helpers don't need write access.
Signed-off-by: NRob Clark <robdclark@chromium.org>
Reviewed-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: NWill Deacon <will@kernel.org>

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: NRob Clark <robdclark@chromium.org>
Signed-off-by: NJordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: NRob Clark <robdclark@chromium.org>
Reviewed-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: NWill Deacon <will@kernel.org>

Enable TTBR1 for a context bank if IO_PGTABLE_QUIRK_ARM_TTBR1 is selected
by the io-pgtable configuration.
Signed-off-by: NJordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: NRob Clark <robdclark@chromium.org>
Reviewed-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: NWill Deacon <will@kernel.org>

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: NJordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: NRob Clark <robdclark@chromium.org>
Reviewed-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: NWill Deacon <will@kernel.org>

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: NJean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20200918141856.629722-1-jean-philippe@linaro.orgSigned-off-by: NWill Deacon <will@kernel.org>

Polling by MSI isn't necessarily faster than polling by SEV. Tests on
hi1620 show hns3 100G NIC network throughput can improve from 25G to
27G if we disable MSI polling while running 16 netperf threads sending
UDP packets in size 32KB. TX throughput can improve from 7G to 7.7G for
single thread.
The reason for the throughput improvement is that the latency to poll
the completion of CMD_SYNC becomes smaller. After sending a CMD_SYNC
in an empty cmd queue, typically we need to wait for 280ns using MSI
polling. But we only need around 190ns after disabling MSI polling.
This patch provides a command line option so that users can decide to
use MSI polling or not based on their tests.
Signed-off-by: NBarry Song <song.bao.hua@hisilicon.com>
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20200827092957.22500-4-song.bao.hua@hisilicon.comSigned-off-by: NWill Deacon <will@kernel.org>

Just use module_param() - going out of the way to specify a "different"
name that's identical to the variable name is silly.
Signed-off-by: NBarry Song <song.bao.hua@hisilicon.com>
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20200827092957.22500-3-song.bao.hua@hisilicon.comSigned-off-by: NWill Deacon <will@kernel.org>

This fixed the below checkpatch issue:
WARNING: Symbolic permissions 'S_IRUGO' are not preferred. Consider using
octal permissions '0444'.
417: FILE: drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c:417:
module_param_named(disable_bypass, disable_bypass, bool, S_IRUGO);
Signed-off-by: NBarry Song <song.bao.hua@hisilicon.com>
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20200827092957.22500-2-song.bao.hua@hisilicon.comSigned-off-by: NWill Deacon <will@kernel.org>

The actual size of level-1 stream table is l1size. This looks like an
oversight on commit d2e88e7c ("iommu/arm-smmu: Fix LOG2SIZE setting
for 2-level stream tables") which forgot to update the @size in error
message as well.

As memory allocation failure is already bad enough, nothing worse would
happen. But let's be careful.
Signed-off-by: NZenghui Yu <yuzenghui@huawei.com>
Link: https://lore.kernel.org/r/20200826141758.341-1-yuzenghui@huawei.comSigned-off-by: NWill Deacon <will@kernel.org>

Pull crypto fixes from Herbert Xu:

 - fix regression in af_alg that affects iwd

 - restore polling delay in qat

 - fix double free in ingenic on error path

 - fix potential build failure in sa2ul due to missing Kconfig dependency

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: af_alg - Work around empty control messages without MSG_MORE
  crypto: sa2ul - add Kconfig selects to fix build error
  crypto: ingenic - Drop kfree for memory allocated with devm_kzalloc
  crypto: qat - add delay before polling mailbox

Pull x86 fixes from Thomas Gleixner:
 "Three interrupt related fixes for X86:

   - Move disabling of the local APIC after invoking fixup_irqs() to
     ensure that interrupts which are incoming are noted in the IRR and
     not ignored.

   - Unbreak affinity setting.

     The rework of the entry code reused the regular exception entry
     code for device interrupts. The vector number is pushed into the
     errorcode slot on the stack which is then lifted into an argument
     and set to -1 because that's regs->orig_ax which is used in quite
     some places to check whether the entry came from a syscall.

     But it was overlooked that orig_ax is used in the affinity cleanup
     code to validate whether the interrupt has arrived on the new
     target. It turned out that this vector check is pointless because
     interrupts are never moved from one vector to another on the same
     CPU. That check is a historical leftover from the time where x86
     supported multi-CPU affinities, but not longer needed with the now
     strict single CPU affinity. Famous last words ...

   - Add a missing check for an empty cpumask into the matrix allocator.

     The affinity change added a warning to catch the case where an
     interrupt is moved on the same CPU to a different vector. This
     triggers because a condition with an empty cpumask returns an
     assignment from the allocator as the allocator uses for_each_cpu()
     without checking the cpumask for being empty. The historical
     inconsistent for_each_cpu() behaviour of ignoring the cpumask and
     unconditionally claiming that CPU0 is in the mask struck again.
     Sigh.

  plus a new entry into the MAINTAINER file for the HPE/UV platform"

* tag 'x86-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/matrix: Deal with the sillyness of for_each_cpu() on UP
  x86/irq: Unbreak interrupt affinity setting
  x86/hotplug: Silence APIC only after all interrupts are migrated
  MAINTAINERS: Add entry for HPE Superdome Flex (UV) maintainers

Pull irq fixes from Thomas Gleixner:
 "A set of fixes for interrupt chip drivers:

   - Revert the platform driver conversion of interrupt chip drivers as
     it turned out to create more problems than it solves.

   - Fix a trivial typo in the new module helpers which made probing
     reliably fail.

   - Small fixes in the STM32 and MIPS Ingenic drivers

   - The TI firmware rework which had badly managed dependencies and had
     to wait post rc1"

* tag 'irq-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/ingenic: Leave parent IRQ unmasked on suspend
  irqchip/stm32-exti: Avoid losing interrupts due to clearing pending bits by mistake
  irqchip: Revert modular support for drivers using IRQCHIP_PLATFORM_DRIVER helperse
  irqchip: Fix probing deferal when using IRQCHIP_PLATFORM_DRIVER helpers
  arm64: dts: k3-am65: Update the RM resource types
  arm64: dts: k3-am65: ti-sci-inta/intr: Update to latest bindings
  arm64: dts: k3-j721e: ti-sci-inta/intr: Update to latest bindings
  irqchip/ti-sci-inta: Add support for INTA directly connecting to GIC
  irqchip/ti-sci-inta: Do not store TISCI device id in platform device id field
  dt-bindings: irqchip: Convert ti, sci-inta bindings to yaml
  dt-bindings: irqchip: ti, sci-inta: Update docs to support different parent.
  irqchip/ti-sci-intr: Add support for INTR being a parent to INTR
  dt-bindings: irqchip: Convert ti, sci-intr bindings to yaml
  dt-bindings: irqchip: ti, sci-intr: Update bindings to drop the usage of gic as parent
  firmware: ti_sci: Add support for getting resource with subtype
  firmware: ti_sci: Drop unused structure ti_sci_rm_type_map
  firmware: ti_sci: Drop the device id to resource type translation

Pull scheduler fix from Thomas Gleixner:
 "A single fix for the scheduler:

   - Make is_idle_task() __always_inline to prevent the compiler from
     putting it out of line into the wrong section because it's used
     inside noinstr sections"

* tag 'sched-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Use __always_inline on is_idle_task()

Pull locking fixes from Thomas Gleixner:
 "A set of fixes for lockdep, tracing and RCU:

   - Prevent recursion by using raw_cpu_* operations

   - Fixup the interrupt state in the cpu idle code to be consistent

   - Push rcu_idle_enter/exit() invocations deeper into the idle path so
     that the lock operations are inside the RCU watching sections

   - Move trace_cpu_idle() into generic code so it's called before RCU
     goes idle.

   - Handle raw_local_irq* vs. local_irq* operations correctly

   - Move the tracepoints out from under the lockdep recursion handling
     which turned out to be fragile and inconsistent"

* tag 'locking-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep,trace: Expose tracepoints
  lockdep: Only trace IRQ edges
  mips: Implement arch_irqs_disabled()
  arm64: Implement arch_irqs_disabled()
  nds32: Implement arch_irqs_disabled()
  locking/lockdep: Cleanup
  x86/entry: Remove unused THUNKs
  cpuidle: Move trace_cpu_idle() into generic code
  cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED generic
  sched,idle,rcu: Push rcu_idle deeper into the idle path
  cpuidle: Fixup IRQ state
  lockdep: Use raw_cpu_*() for per-cpu variables

Pull cfis fix from Steve French:
 "DFS fix for referral problem when using SMB1"

* tag '5.9-rc2-smb-fix' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix check of tcon dfs in smb1

Pull powerpc fixes from Michael Ellerman:

 - Revert our removal of PROT_SAO, at least one user expressed an
   interest in using it on Power9. Instead don't allow it to be used in
   guests unless enabled explicitly at compile time.

 - A fix for a crash introduced by a recent change to FP handling.

 - Revert a change to our idle code that left Power10 with no idle
   support.

 - One minor fix for the new scv system call path to set PPR.

 - Fix a crash in our "generic" PMU if branch stack events were enabled.

 - A fix for the IMC PMU, to correctly identify host kernel samples.

 - The ADB_PMU powermac code was found to be incompatible with
   VMAP_STACK, so make them incompatible in Kconfig until the code can
   be fixed.

 - A build fix in drivers/video/fbdev/controlfb.c, and a documentation
   fix.

Thanks to Alexey Kardashevskiy, Athira Rajeev, Christophe Leroy,
Giuseppe Sacco, Madhavan Srinivasan, Milton Miller, Nicholas Piggin,
Pratik Rajesh Sampat, Randy Dunlap, Shawn Anastasio, Vaidyanathan
Srinivasan.

* tag 'powerpc-5.9-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/32s: Disable VMAP stack which CONFIG_ADB_PMU
  Revert "powerpc/powernv/idle: Replace CPU feature check with PVR check"
  powerpc/perf: Fix reading of MSR[HV/PR] bits in trace-imc
  powerpc/perf: Fix crashes with generic_compat_pmu & BHRB
  powerpc/64s: Fix crash in load_fp_state() due to fpexc_mode
  powerpc/64s: scv entry should set PPR
  Documentation/powerpc: fix malformed table in syscall64-abi
  video: fbdev: controlfb: Fix build for COMPILE_TEST=y && PPC_PMAC=n
  selftests/powerpc: Update PROT_SAO test to skip ISA 3.1
  powerpc/64s: Disallow PROT_SAO in LPARs by default
  Revert "powerpc/64s: Remove PROT_SAO support"

Pull USB fixes from Greg KH:
 "Let's try this again...  Here are some USB fixes for 5.9-rc3.

  This differs from the previous pull request for this release in that
  the usb gadget patch now does not break some systems, and actually
  does what it was intended to do. Many thanks to Marek Szyprowski for
  quickly noticing and testing the patch from Andy Shevchenko to resolve
  this issue.

  Additionally, some more new USB quirks have been added to get some new
  devices to work properly based on user reports.

  Other than that, the patches are all here, and they contain:

   - usb gadget driver fixes

   - xhci driver fixes

   - typec fixes

   - new quirks and ids

   - fixes for USB patches that went into 5.9-rc1.

  All of these have been tested in linux-next with no reported issues"

* tag 'usb-5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (33 commits)
  usb: storage: Add unusual_uas entry for Sony PSZ drives
  USB: Ignore UAS for JMicron JMS567 ATA/ATAPI Bridge
  usb: host: ohci-exynos: Fix error handling in exynos_ohci_probe()
  USB: gadget: u_f: Unbreak offset calculation in VLAs
  USB: quirks: Ignore duplicate endpoint on Sound Devices MixPre-D
  usb: typec: tcpm: Fix Fix source hard reset response for TDA 2.3.1.1 and TDA 2.3.1.2 failures
  USB: PHY: JZ4770: Fix static checker warning.
  USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb()
  USB: gadget: u_f: add overflow checks to VLA macros
  xhci: Always restore EP_SOFT_CLEAR_TOGGLE even if ep reset failed
  xhci: Do warm-reset when both CAS and XDEV_RESUME are set
  usb: host: xhci: fix ep context print mismatch in debugfs
  usb: uas: Add quirk for PNY Pro Elite
  tools: usb: move to tools buildsystem
  USB: Fix device driver race
  USB: Also match device drivers using the ->match vfunc
  usb: host: xhci-tegra: fix tegra_xusb_get_phy()
  usb: host: xhci-tegra: otg usb2/usb3 port init
  usb: hcd: Fix use after free in usb_hcd_pci_remove()
  usb: typec: ucsi: Hold con->lock for the entire duration of ucsi_register_port()
  ...

Pull EDAC fix from Borislav Petkov:
 "A fix to properly clear ghes_edac driver state on driver remove so
  that a subsequent load can probe the system properly (Shiju Jose)"

* tag 'edac_urgent_for_v5.9_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
  EDAC/ghes: Fix NULL pointer dereference in ghes_edac_register()

Pull dma-mapping fix from Christoph Hellwig:
 "Fix a possibly uninitialized variable (Dan Carpenter)"

* tag 'dma-mapping-5.9-2' of git://git.infradead.org/users/hch/dma-mapping:
  dma-pool: Fix an uninitialized variable bug in atomic_pool_expand()

Most of the CPU mask operations behave the same way, but for_each_cpu() and
it's variants ignore the cpumask argument and claim that CPU0 is always in
the mask. This is historical, inconsistent and annoying behaviour.

The matrix allocator uses for_each_cpu() and can be called on UP with an
empty cpumask. The calling code does not expect that this succeeds but
until commit e027ffff ("x86/irq: Unbreak interrupt affinity setting")
this went unnoticed. That commit added a WARN_ON() to catch cases which
move an interrupt from one vector to another on the same CPU. The warning
triggers on UP.

Add a check for the cpumask being empty to prevent this.

Fixes: 2f75d9e1 ("genirq: Implement bitmap matrix allocator")
Reported-by: Nkernel test robot <rong.a.chen@intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org

Merge tag 'fallthrough-fixes-5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux

Pull fallthrough fixes from Gustavo A. R. Silva:
 "Fix some minor issues introduced by the recent treewide fallthrough
  conversions:

   - Fix identation issue

   - Fix erroneous fallthrough annotation

   - Remove unnecessary fallthrough annotation

   - Fix code comment changed by fallthrough conversion"

* tag 'fallthrough-fixes-5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
  arm64/cpuinfo: Remove unnecessary fallthrough annotation
  media: dib0700: Fix identation issue in dib8096_set_param_override()
  afs: Remove erroneous fallthough annotation
  iio: dpot-dac: fix code comment in dpot_dac_read_raw()

Commit ef91bb19 ("kernel.h: Silence sparse warning in
lower_32_bits") caused new warnings to show in the fsldma driver, but
that commit was not to blame: it only exposed some very incorrect code
that tried to take the low 32 bits of an address.

That made no sense for multiple reasons, the most notable one being that
that code was intentionally limited to only 32-bit ppc builds, so "only
low 32 bits of an address" was completely nonsensical.  There were no
high bits to mask off to begin with.

But even more importantly fropm a correctness standpoint, turning the
address into an integer then caused the subsequent address arithmetic to
be completely wrong too, and the "+1" actually incremented the address
by one, rather than by four.

Which again was incorrect, since the code was reading two 32-bit values
and trying to make a 64-bit end result of it all.  Surprisingly, the
iowrite64() did not suffer from the same odd and incorrect model.

This code has never worked, but it's questionable whether anybody cared:
of the two users that actually read the 64-bit value (by way of some C
preprocessor hackery and eventually the 'get_cdar()' inline function),
one of them explicitly ignored the value, and the other one might just
happen to work despite the incorrect value being read.

This patch at least makes it not fail the build any more, and makes the
logic superficially sane.  Whether it makes any difference to the code
_working_ or not shall remain a mystery.
Compile-tested-by: NGuenter Roeck <linux@roeck-us.net>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull i2c fixes from Wolfram Sang:
 "A core fix for ACPI matching and two driver bugfixes"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: iproc: Fix shifting 31 bits
  i2c: rcar: in slave mode, clear NACK earlier
  i2c: acpi: Remove dead code, i.e. i2c_acpi_match_device()
  i2c: core: Don't fail PRP0001 enumeration when no ID table exist

Pull s390 fixes from Vasily Gorbik:

 - Disable preemption trace in percpu macros since the lockdep code
   itself uses percpu variables now and it causes recursions.

 - Fix kernel space 4-level paging broken by recent vmem rework.

* tag 's390-5.9-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/vmem: fix vmem_add_range for 4-level paging
  s390: don't trace preemption in percpu macros

Pull xen fixes from Juergen Gross:
 "Two fixes for Xen: one needed for ongoing work to support virtio with
  Xen, and one for a corner case in IRQ handling with Xen"

* tag 'for-linus-5.9-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  arm/xen: Add misuse warning to virt_to_gfn
  xen/xenbus: Fix granting of vmalloc'd memory
  XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN data pointer which contains XEN specific information.

Merge tag 'hwmon-for-v5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:

 - Fix tempeerature scale in gsc-hwmon driver

 - Fix divide by 0 error in nct7904 driver

 - Drop non-existing attribute from pmbus/isl68137 driver

 - Fix status check in applesmc driver

* tag 'hwmon-for-v5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (gsc-hwmon) Scale temperature to millidegrees
  hwmon: (applesmc) check status earlier.
  hwmon: (nct7904) Correct divide by 0
  hwmon: (pmbus/isl68137) remove READ_TEMPERATURE_1 telemetry for RAA228228

Pull block fixes from Jens Axboe:

 - nbd timeout fix (Hou)

 - device size fix for loop LOOP_CONFIGURE (Martijn)

 - MD pull from Song with raid5 stripe size fix (Yufen)

* tag 'block-5.9-2020-08-28' of git://git.kernel.dk/linux-block:
  md/raid5: make sure stripe_size as power of two
  loop: Set correct device size when using LOOP_CONFIGURE
  nbd: restore default timeout when setting it to zero

Pull io_uring fixes from Jens Axboe:
 "A few fixes in here, all based on reports and test cases from folks
  using it. Most of it is stable material as well:

   - Hashed work cancelation fix (Pavel)

   - poll wakeup signalfd fix

   - memlock accounting fix

   - nonblocking poll retry fix

   - ensure we never return -ERESTARTSYS for reads

   - ensure offset == -1 is consistent with preadv2() as documented

   - IOPOLL -EAGAIN handling fixes

   - remove useless task_work bounce for block based -EAGAIN retry"

* tag 'io_uring-5.9-2020-08-28' of git://git.kernel.dk/linux-block:
  io_uring: don't bounce block based -EAGAIN retry off task_work
  io_uring: fix IOPOLL -EAGAIN retries
  io_uring: clear req->result on IOPOLL re-issue
  io_uring: make offset == -1 consistent with preadv2/pwritev2
  io_uring: ensure read requests go through -ERESTART* transformation
  io_uring: don't use poll handler if file can't be nonblocking read/written
  io_uring: fix imbalanced sqo_mm accounting
  io_uring: revert consumed iov_iter bytes on error
  io-wq: fix hang after cancelling pending hashed work
  io_uring: don't recurse on tsk->sighand->siglock with signalfd

Pull device properties framework fix from Rafael Wysocki:
 "Prevent the promotion of the secondary firmware node of a device to
  the primary one from leaking a pointer (Heikki Krogerus)"

* tag 'devprop-5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  device property: Fix the secondary firmware node handling in set_primary_fwnode()

Pull ACPI fixes from Rafael Wysocki:
 "These fix two recent issues in the ACPI memory mappings management
  code and tighten up error handling in the ACPI driver for AMD SoCs
  (APD).

  Specifics:

   - Avoid redundant rounding to the page size in acpi_os_map_iomem() to
     address a recently introduced issue with the EFI memory map
     permission check on ARM64 (Ard Biesheuvel).

   - Fix acpi_release_memory() to wait until the memory mappings
     released by it have been really unmapped (Rafael Wysocki).

   - Make the ACPI driver for AMD SoCs (APD) check the return value of
     acpi_dev_get_property() to avoid failures in the cases when the
     device property under inspection is missing (Furquan Shaikh)"

* tag 'acpi-5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: OSL: Prevent acpi_release_memory() from returning too early
  ACPI: ioremap: avoid redundant rounding to OS page size
  ACPI: SoC: APD: Check return value of acpi_dev_get_property()

Pull power management fixes from Rafael Wysocki:
 "These fix the recently added Tegra194 cpufreq driver and the handling
  of devices using runtime PM during system-wide suspend, improve the
  intel_pstate driver documentation and clean up the cpufreq core.

  Specifics:

   - Make the recently added Tegra194 cpufreq driver use
     read_cpuid_mpir() instead of cpu_logical_map() to avoid exporting
     logical_cpu_map (Sumit Gupta).

   - Drop the automatic system wakeup event reporting for devices with
     pending runtime-resume requests during system-wide suspend to avoid
     spurious aborts of the suspend flow (Rafael Wysocki).

   - Fix build warning in the intel_pstate driver documentation and
     improve the wording in there (Randy Dunlap).

   - Clean up two pieces of code in the cpufreq core (Viresh Kumar)"

* tag 'pm-5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: Use WARN_ON_ONCE() for invalid relation
  cpufreq: No need to verify cpufreq_driver in show_scaling_cur_freq()
  PM: sleep: core: Fix the handling of pending runtime resume requests
  Documentation: fix pm/intel_pstate build warning and wording
  cpufreq: replace cpu_logical_map() with read_cpuid_mpir()