Merge branch 'fixes-dra7' into fixes

Merge tag 'v5.2-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into fbdev-for-next

Linux 5.2-rc1

Sync with upstream (which now contains fbdev-v5.2 changes) to
prepare a base

Merge tag 'v5.2-rc1' of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into fbdev-for-next

Linux 5.2-rc1

Sync with upstream (which now contains fbdev-v5.2 changes) to
prepare a base for fbdev-v5.3 changes.

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Merge tag 'v5.2-rc1' into spi-5.3

Linux 5.2-rc1

Merge tag 'v5.2-rc1' into regulator-5.3

Linux 5.2-rc1

Merge tag 'v5.2-rc1' into asoc-5.3

Linux 5.2-rc1

Merge branch 'linus' into x86/urgent, to pick up dependent changes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
"This is mostly update of the usual drivers: qla2xxx, qedf, smartpqi,
hpsa

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
"This is mostly update of the usual drivers: qla2xxx, qedf, smartpqi,
hpsa, lpfc, ufs, mpt3sas, ibmvfc and hisi_sas. Plus number of minor
changes, spelling fixes and other trivia"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (298 commits)
scsi: qla2xxx: Avoid that lockdep complains about unsafe locking in tcm_qla2xxx_close_session()
scsi: qla2xxx: Avoid that qlt_send_resp_ctio() corrupts memory
scsi: qla2xxx: Fix hardirq-unsafe locking
scsi: qla2xxx: Complain loudly about reference count underflow
scsi: qla2xxx: Use __le64 instead of uint32_t[2] for sending DMA addresses to firmware
scsi: qla2xxx: Introduce the dsd32 and dsd64 data structures
scsi: qla2xxx: Check the size of firmware data structures at compile time
scsi: qla2xxx: Pass little-endian values to the firmware
scsi: qla2xxx: Fix race conditions in the code for aborting SCSI commands
scsi: qla2xxx: Use an on-stack completion in qla24xx_control_vp()
scsi: qla2xxx: Make qla24xx_async_abort_cmd() static
scsi: qla2xxx: Remove unnecessary locking from the target code
scsi: qla2xxx: Remove qla_tgt_cmd.released
scsi: qla2xxx: Complain if a command is released that is owned by the firmware
scsi: qla2xxx: target: Fix offline port handling and host reset handling
scsi: qla2xxx: Fix abort handling in tcm_qla2xxx_write_pending()
scsi: qla2xxx: Fix error handling in qlt_alloc_qfull_cmd()
scsi: qla2xxx: Simplify qlt_send_term_imm_notif()
scsi: qla2xxx: Fix use-after-free issues in qla2xxx_qpair_sp_free_dma()
scsi: qla2xxx: Fix a qla24xx_enable_msix() error path
...

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scsi: mpt3sas: Irq poll to avoid CPU hard lockups

Issue Description:
We have seen cpu lock up issue from fields if system has greater (more than
96) logical cpu count. SAS3.0 controller (Invader se

scsi: mpt3sas: Irq poll to avoid CPU hard lockups

Issue Description:
We have seen cpu lock up issue from fields if system has greater (more than
96) logical cpu count. SAS3.0 controller (Invader series) supports at max
96 msix vector and SAS3.5 product (Ventura) supports at max 128 msix
vectors.

This may be a generic issue (if PCI device supports completion on multiple
reply queues). Let me explain it w.r.t to mpt3sas supported h/w just to
simplify the problem and possible changes to handle such issues. IT HBA
(mpt3sas) supports multiple reply queues in completion path. Driver creates
MSI-x vectors for controller as "min of (FW supported Reply queue, Logical
CPUs)". If submitter is not interrupted via completion on same CPU, there
is a loop in the IO path. This behavior can cause hard/soft CPU lockups, IO
timeout, system sluggish etc.

Example - one CPU (e.g. CPU A) is busy submitting the IOs and another CPU
(e.g. CPU B) is busy with processing the corresponding IO's reply
descriptors from reply descriptor queue upon receiving the interrupts from
HBA. If the CPU A is continuously pumping the IOs then always CPU B (which
is executing the ISR) will see the valid reply descriptors in the reply
descriptor queue and it will be continuously processing those reply
descriptor in a loop without quitting the ISR handler.

Mpt3sas driver will exit ISR handler if it finds unused reply descriptor in
the reply descriptor queue. Since CPU A will be continuously sending the
IOs, CPU B may always see a valid reply descriptor (posted by HBA Firmware
after processing the IO) in the reply descriptor queue. In worst case,
driver will not quit from this loop in the ISR handler. Eventually, CPU
lockup will be detected by watchdog.

Above mentioned behavior is not common if "rq_affinity" set to 2 or
affinity_hint is honored by irqbalance as "exact". If rq_affinity is set
to 2, submitter will be always interrupted via completion on same CPU. If
irqbalance is using "exact" policy, interrupt will be delivered to
submitter CPU.

If CPU counts to MSI-X vectors (reply descriptor Queues) count ratio is not
1:1, we still have exposure of issue explained above and for that we don't
have any solution.

Exposure of soft/hard lockup if CPU count is more than MSI-x supported by
device.

If CPUs count to MSI-x vectors count ratio is not 1:1, (Other way, if CPU
counts to MSI-x vector count ratio is something like X:1, where X > 1) then
'exact' irqbalance policy OR rq_affinity = 2 won't help to avoid CPU
hard/soft lockups. There won't be any one to one mapping between CPU to
MSI-x vector instead one MSI-x interrupt (or reply descriptor queue) is
shared with group/set of CPUs and there is a possibility of having a loop
in the IO path within that CPU group and may observe lockups.

For example: Consider a system having two NUMA nodes and each node having
four logical CPUs and also consider that number of MSI-x vectors enabled on
the HBA is two, then CPUs count to MSI-x vector count ratio as 4:1. e.g.
MSIx vector 0 is affinity to CPU 0, CPU 1, CPU 2 & CPU 3 of NUMA node 0 and
MSI-x vector 1 is affinity to CPU 4, CPU 5, CPU 6 & CPU 7 of NUMA node 1.

numactl --hardware
available: 2 nodes (0-1)
node 0 cpus: 0 1 2 3 --> MSI-x 0
node 0 size: 65536 MB
node 0 free: 63176 MB
node 1 cpus: 4 5 6 7 -->MSI-x 1
node 1 size: 65536 MB
node 1 free: 63176 MB

Assume that user started an application which uses all the CPUs of NUMA
node 0 for issuing the IOs. Only one CPU from affinity list (it can be any
cpu since this behavior depends upon irqbalance) CPU0 will receive the
interrupts from MSIx vector 0 for all the IOs. Eventually, CPU 0 IO
submission percentage will be decreasing and ISR processing percentage will
be increasing as it is more busy with processing the interrupts. Gradually
IO submission percentage on CPU 0 will be zero and it's ISR processing
percentage will be 100 percentage as IO loop has already formed within the
NUMA node 0, i.e. CPU 1, CPU 2 & CPU 3 will be continuously busy with
submitting the heavy IOs and only CPU 0 is busy in the ISR path as it
always find the valid reply descriptor in the reply descriptor
queue. Eventually, we will observe the hard lockup here.

Chances of occurring of hard/soft lockups are directly proportional to
value of X. If value of X is high, then chances of observing CPU lockups is
high.

Solution: Use IRQ poll interface defined in " irq_poll.c". mpt3sas driver
will execute ISR routine in Softirq context and it will always quit the
loop based on budget provided in IRQ poll interface.

In these scenarios (i.e. where CPUs count to MSI-X vectors count ratio is
X:1 (where X > 1)), IRQ poll interface will avoid CPU hard lockups due to
voluntary exit from the reply queue processing based on budget. Note -
Only one MSI-x vector is busy doing processing.

Irqstat output:

IRQs / 1 second(s)
IRQ# TOTAL NODE0 NODE1 NODE2 NODE3 NAME
44 122871 122871 0 0 0 IR-PCI-MSI-edge mpt3sas0-msix0
45 0 0 0 0 0 IR-PCI-MSI-edge mpt3sas0-msix1

We use this approach only if cpu count is more than FW supported MSI-x
vector

Signed-off-by: Suganath Prabu <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

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Merge branch 'master' into for-next

Sync with Linus' tree so that patches against newer codebase can be applied.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Merge branch 'topic/update-bits' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap into asoc-rcar

Merge remote-tracking branch 'linusw-gpio/for-next' into devm_gpiochip

Base for demv_gpiochip_add_data() and devm_gpiochip_remove().

Merge tag 'v4.5-rc5' into asoc-mtk

Linux 4.5-rc5

Merge branch 'topic/acpi' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-pxa2xx

Merge branch 'linus' into efi/core, to refresh the branch and to pick up recent fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'v4.5-rc1' into patchwork

Linux 4.5-rc1

* tag 'v4.5-rc1': (11309 commits)
Linux 4.5-rc1
ideapad-laptop: Add Lenovo Yoga 700 to no_hw_rfkill dmi list
MAINTAINERS: Combine multiple te

Merge tag 'v4.5-rc1' into patchwork

Linux 4.5-rc1

* tag 'v4.5-rc1': (11309 commits)
Linux 4.5-rc1
ideapad-laptop: Add Lenovo Yoga 700 to no_hw_rfkill dmi list
MAINTAINERS: Combine multiple telemetry entries
intel_telemetry_debugfs: Fix unused warnings in telemetry debugfs
vmstat: Remove BUG_ON from vmstat_update
MIPS: zboot: Add support for serial debug using the PROM
MIPS: zboot: Avoid useless rebuilds
MIPS: BMIPS: Enable ARCH_WANT_OPTIONAL_GPIOLIB
MIPS: bcm63xx: nvram: Remove unused bcm63xx_nvram_get_psi_size() function
MIPS: bcm963xx: Update bcm_tag field image_sequence
MIPS: bcm963xx: Move extended flash address to bcm_tag header file
MIPS: bcm963xx: Move Broadcom BCM963xx image tag data structure
MIPS: bcm63xx: nvram: Use nvram structure definition from header file
MIPS: bcm963xx: Add Broadcom BCM963xx board nvram data structure
MAINTAINERS: Add KVM for MIPS entry
MIPS: KVM: Add missing newline to kvm_err()
MIPS: Move KVM specific opcodes into asm/inst.h
MIPS: KVM: Use cacheops.h definitions
MIPS: Break down cacheops.h definitions
MIPS: Use EXCCODE_ constants with set_except_vector()
...

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Merge tag 'v4.4'

Linux 4.4

Orangefs: merge with V4.4

Merge tag 'v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into current

Linux 4.4

Orangefs: Merge tag 'v4.4-rc1' into for-next

Linux 4.4-rc1

Merge branches 'for-4.4/upstream-fixes', 'for-4.5/async-suspend', 'for-4.5/container-of-cleanups', 'for-4.5/core', 'for-4.5/i2c-hid', 'for-4.5/logitech', 'for-4.5/multitouch', 'for-4.5/sony', 'for-4.

Merge branches 'for-4.4/upstream-fixes', 'for-4.5/async-suspend', 'for-4.5/container-of-cleanups', 'for-4.5/core', 'for-4.5/i2c-hid', 'for-4.5/logitech', 'for-4.5/multitouch', 'for-4.5/sony', 'for-4.5/upstream' and 'for-4.5/wacom' into for-linus

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Merge branches 'clockevents/4.4-fixes' and 'clockevents/4.5-fixes' of http://git.linaro.org/people/daniel.lezcano/linux into timers/urgent

Pull in fixes from Daniel Lezcano:

- Fix the vt8500 timer

Merge branches 'clockevents/4.4-fixes' and 'clockevents/4.5-fixes' of http://git.linaro.org/people/daniel.lezcano/linux into timers/urgent

Pull in fixes from Daniel Lezcano:

- Fix the vt8500 timer leading to a system lock up when dealing with too
small delta (Roman Volkov)

- Select the CLKSRC_MMIO when the fsl_ftm_timer is enabled with COMPILE_TEST
(Daniel Lezcano)

- Prevent to compile timers using the 'iomem' API when the architecture has
not HAS_IOMEM set (Richard Weinberger)

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Merge branch 'next' into for-linus

Prepare first round of input updates for 4.5 merge window.

Merge branch 'jejb-scsi' into misc

Merge tag 'kvm-arm-for-4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-next

KVM/ARM changes for Linux v4.5

- Complete rewrite of the arm64 world switch in C, hopefull

Merge tag 'kvm-arm-for-4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-next

KVM/ARM changes for Linux v4.5

- Complete rewrite of the arm64 world switch in C, hopefully
paving the way for more sharing with the 32bit code, better
maintainability and easier integration of new features.
Also smaller and slightly faster in some cases...
- Support for 16bit VM identifiers
- Various cleanups

show more ...

Merge branch 'goodix' into next

Merge several improvements to Goodix touchscreen driver:
- power management support
- configuration upload
- axis swapping and inversion

Merge branch 'sched/urgent' into sched/core, to pick up fixes before merging new patches

Signed-off-by: Ingo Molnar <mingo@kernel.org>