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  1. 26 Jul, 2019 21 commits
  3. 21 Jul, 2019 19 commits
    • Greg Kroah-Hartman's avatar
      Linux 5.1.19 · 0d4f1b2a
      Greg Kroah-Hartman authored
      0d4f1b2a
    • Jiri Slaby's avatar
      x86/entry/32: Fix ENDPROC of common_spurious · 0e921583
      Jiri Slaby authored 
      [ Upstream commit 1cbec37b ]

common_spurious is currently ENDed erroneously. common_interrupt is used
in its ENDPROC. So fix this mistake.

Found by my asm macros rewrite patchset.

Fixes: f8a8fe61 ("x86/irq: Seperate unused system vectors from spurious entry again")
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190709063402.19847-1-jslaby@suse.czSigned-off-by: default avatarSasha Levin <sashal@kernel.org>
      0e921583
    • Haren Myneni's avatar
      crypto/NX: Set receive window credits to max number of CRBs in RxFIFO · 845912c3
      Haren Myneni authored 
      commit e52d484d upstream.

System gets checkstop if RxFIFO overruns with more requests than the
maximum possible number of CRBs in FIFO at the same time. The max number
of requests per window is controlled by window credits. So find max
CRBs from FIFO size and set it to receive window credits.

Fixes: b0d6c9ba ("crypto/nx: Add P9 NX support for 842 compression engine")
CC: stable@vger.kernel.org # v4.14+
Signed-off-by: default avatarHaren Myneni <haren@us.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      845912c3
    • Christophe Leroy's avatar
      crypto: talitos - fix hash on SEC1. · 5b7e0364
      Christophe Leroy authored 
      commit 58cdbc6d upstream.

On SEC1, hash provides wrong result when performing hashing in several
steps with input data SG list has more than one element. This was
detected with CONFIG_CRYPTO_MANAGER_EXTRA_TESTS:

[   44.185947] alg: hash: md5-talitos test failed (wrong result) on test vector 6, cfg="random: may_sleep use_finup src_divs=[<reimport>25.88%@+8063, <flush>24.19%@+9588, 28.63%@+16333, <reimport>4.60%@+6756, 16.70%@+16281] dst_divs=[71.61%@alignmask+16361, 14.36%@+7756, 14.3%@+"
[   44.325122] alg: hash: sha1-talitos test failed (wrong result) on test vector 3, cfg="random: inplace use_final src_divs=[<flush,nosimd>16.56%@+16378, <reimport>52.0%@+16329, 21.42%@alignmask+16380, 10.2%@alignmask+16380] iv_offset=39"
[   44.493500] alg: hash: sha224-talitos test failed (wrong result) on test vector 4, cfg="random: use_final nosimd src_divs=[<reimport>52.27%@+7401, <reimport>17.34%@+16285, <flush>17.71%@+26, 12.68%@+10644] iv_offset=43"
[   44.673262] alg: hash: sha256-talitos test failed (wrong result) on test vector 4, cfg="random: may_sleep use_finup src_divs=[<reimport>60.6%@+12790, 17.86%@+1329, <reimport>12.64%@alignmask+16300, 8.29%@+15, 0.40%@+13506, <reimport>0.51%@+16322, <reimport>0.24%@+16339] dst_divs"

This is due to two issues:
- We have an overlap between the buffer used for copying the input
data (SEC1 doesn't do scatter/gather) and the chained descriptor.
- Data copy is wrong when the previous hash left less than one
blocksize of data to hash, implying a complement of the previous
block with a few bytes from the new request.

Fix it by:
- Moving the second descriptor after the buffer, as moving the buffer
after the descriptor would make it more complex for other cipher
operations (AEAD, ABLKCIPHER)
- Skip the bytes taken from the new request to complete the previous
one by moving the SG list forward.

Fixes: 37b5e889 ("crypto: talitos - chain in buffered data for ahash on SEC1")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5b7e0364
    • Christophe Leroy's avatar
      crypto: talitos - move struct talitos_edesc into talitos.h · 5da29258
      Christophe Leroy authored 
      commit d44769e4 upstream.

Moves struct talitos_edesc into talitos.h so that it can be used
from any place in talitos.c

It will be required for next patch ("crypto: talitos - fix hash
on SEC1")
Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5da29258
    • Julian Wiedmann's avatar
      s390/qdio: don't touch the dsci in tiqdio_add_input_queues() · 9ca71f3d
      Julian Wiedmann authored 
      commit ac6639cd upstream.

Current code sets the dsci to 0x00000080. Which doesn't make any sense,
as the indicator area is located in the _left-most_ byte.

Worse: if the dsci is the _shared_ indicator, this potentially clears
the indication of activity for a _different_ device.
tiqdio_thinint_handler() will then have no reason to call that device's
IRQ handler, and the device ends up stalling.

Fixes: d0c9d4a8 ("[S390] qdio: set correct bit in dsci")
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9ca71f3d
    • Julian Wiedmann's avatar
      s390/qdio: (re-)initialize tiqdio list entries · 1f5dcaa9
      Julian Wiedmann authored 
      commit e54e4785 upstream.

When tiqdio_remove_input_queues() removes a queue from the tiq_list as
part of qdio_shutdown(), it doesn't re-initialize the queue's list entry
and the prev/next pointers go stale.

If a subsequent qdio_establish() fails while sending the ESTABLISH cmd,
it calls qdio_shutdown() again in QDIO_IRQ_STATE_ERR state and
tiqdio_remove_input_queues() will attempt to remove the queue entry a
second time. This dereferences the stale pointers, and bad things ensue.
Fix this by re-initializing the list entry after removing it from the
list.

For good practice also initialize the list entry when the queue is first
allocated, and remove the quirky checks that papered over this omission.
Note that prior to
commit e5218134 ("s390/qdio: fix access to uninitialized qdio_q fields"),
these checks were bogus anyway.

setup_queues_misc() clears the whole queue struct, and thus needs to
re-init the prev/next pointers as well.

Fixes: 779e6e1c ("[S390] qdio: new qdio driver.")
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1f5dcaa9
    • Heiko Carstens's avatar
      s390: fix stfle zero padding · d6e7f5e8
      Heiko Carstens authored 
      commit 4f18d869 upstream.

The stfle inline assembly returns the number of double words written
(condition code 0) or the double words it would have written
(condition code 3), if the memory array it got as parameter would have
been large enough.

The current stfle implementation assumes that the array is always
large enough and clears those parts of the array that have not been
written to with a subsequent memset call.

If however the array is not large enough memset will get a negative
length parameter, which means that memset clears memory until it gets
an exception and the kernel crashes.

To fix this simply limit the maximum length. Move also the inline
assembly to an extra function to avoid clobbering of register 0, which
might happen because of the added min_t invocation together with code
instrumentation.

The bug was introduced with commit 14375bc4 ("[S390] cleanup
facility list handling") but was rather harmless, since it would only
write to a rather large array. It became a potential problem with
commit 3ab121ab ("[S390] kernel: Add z/VM LGR detection"). Since
then it writes to an array with only four double words, while some
machines already deliver three double words. As soon as machines have
a facility bit within the fifth double a crash on IPL would happen.

Fixes: 14375bc4 ("[S390] cleanup facility list handling")
Cc: <stable@vger.kernel.org> # v2.6.37+
Reviewed-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d6e7f5e8
    • Arnd Bergmann's avatar
      ARC: hide unused function unw_hdr_alloc · d6d65a2f
      Arnd Bergmann authored 
      commit fd5de272 upstream.

As kernelci.org reports, this function is not used in
vdk_hs38_defconfig:

arch/arc/kernel/unwind.c:188:14: warning: 'unw_hdr_alloc' defined but not used [-Wunused-function]

Fixes: bc79c9a7 ("ARC: dw2 unwind: Reinstante unwinding out of modules")
Link: https://kernelci.org/build/id/5d1cae3f59b514300340c132/logs/
Cc: stable@vger.kernel.org
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d6d65a2f
    • Thomas Gleixner's avatar
      x86/irq: Seperate unused system vectors from spurious entry again · 4ac89364
      Thomas Gleixner authored 
      commit f8a8fe61 upstream.

Quite some time ago the interrupt entry stubs for unused vectors in the
system vector range got removed and directly mapped to the spurious
interrupt vector entry point.

Sounds reasonable, but it's subtly broken. The spurious interrupt vector
entry point pushes vector number 0xFF on the stack which makes the whole
logic in __smp_spurious_interrupt() pointless.

As a consequence any spurious interrupt which comes from a vector != 0xFF
is treated as a real spurious interrupt (vector 0xFF) and not
acknowledged. That subsequently stalls all interrupt vectors of equal and
lower priority, which brings the system to a grinding halt.

This can happen because even on 64-bit the system vector space is not
guaranteed to be fully populated. A full compile time handling of the
unused vectors is not possible because quite some of them are conditonally
populated at runtime.

Bring the entry stubs back, which wastes 160 bytes if all stubs are unused,
but gains the proper handling back. There is no point to selectively spare
some of the stubs which are known at compile time as the required code in
the IDT management would be way larger and convoluted.

Do not route the spurious entries through common_interrupt and do_IRQ() as
the original code did. Route it to smp_spurious_interrupt() which evaluates
the vector number and acts accordingly now that the real vector numbers are
handed in.

Fixup the pr_warn so the actual spurious vector (0xff) is clearly
distiguished from the other vectors and also note for the vectored case
whether it was pending in the ISR or not.

 "Spurious APIC interrupt (vector 0xFF) on CPU#0, should never happen."
 "Spurious interrupt vector 0xed on CPU#1. Acked."
 "Spurious interrupt vector 0xee on CPU#1. Not pending!."

Fixes: 2414e021 ("x86: Avoid building unused IRQ entry stubs")
Reported-by: default avatarJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jan Beulich <jbeulich@suse.com>
Link: https://lkml.kernel.org/r/20190628111440.550568228@linutronix.deSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4ac89364
    • Thomas Gleixner's avatar
      x86/irq: Handle spurious interrupt after shutdown gracefully · 3fa8d2a7
      Thomas Gleixner authored 
      commit b7107a67 upstream.

Since the rework of the vector management, warnings about spurious
interrupts have been reported. Robert provided some more information and
did an initial analysis. The following situation leads to these warnings:

   CPU 0                  CPU 1               IO_APIC

                                              interrupt is raised
                                              sent to CPU1
			  Unable to handle
			  immediately
			  (interrupts off,
			   deep idle delay)
   mask()
   ...
   free()
     shutdown()
     synchronize_irq()
     clear_vector()
                          do_IRQ()
                            -> vector is clear

Before the rework the vector entries of legacy interrupts were statically
assigned and occupied precious vector space while most of them were
unused. Due to that the above situation was handled silently because the
vector was handled and the core handler of the assigned interrupt
descriptor noticed that it is shut down and returned.

While this has been usually observed with legacy interrupts, this situation
is not limited to them. Any other interrupt source, e.g. MSI, can cause the
same issue.

After adding proper synchronization for level triggered interrupts, this
can only happen for edge triggered interrupts where the IO-APIC obviously
cannot provide information about interrupts in flight.

While the spurious warning is actually harmless in this case it worries
users and driver developers.

Handle it gracefully by marking the vector entry as VECTOR_SHUTDOWN instead
of VECTOR_UNUSED when the vector is freed up.

If that above late handling happens the spurious detector will not complain
and switch the entry to VECTOR_UNUSED. Any subsequent spurious interrupt on
that line will trigger the spurious warning as before.

Fixes: 464d1230 ("x86/vector: Switch IOAPIC to global reservation mode")
Reported-by: default avatarRobert Hodaszi <Robert.Hodaszi@digi.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>-
Tested-by: default avatarRobert Hodaszi <Robert.Hodaszi@digi.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/20190628111440.459647741@linutronix.deSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3fa8d2a7
    • Thomas Gleixner's avatar
      x86/ioapic: Implement irq_get_irqchip_state() callback · 557f2d49
      Thomas Gleixner authored 
      commit dfe0cf8b upstream.

When an interrupt is shut down in free_irq() there might be an inflight
interrupt pending in the IO-APIC remote IRR which is not yet serviced. That
means the interrupt has been sent to the target CPUs local APIC, but the
target CPU is in a state which delays the servicing.

So free_irq() would proceed to free resources and to clear the vector
because synchronize_hardirq() does not see an interrupt handler in
progress.

That can trigger a spurious interrupt warning, which is harmless and just
confuses users, but it also can leave the remote IRR in a stale state
because once the handler is invoked the interrupt resources might be freed
already and therefore acknowledgement is not possible anymore.

Implement the irq_get_irqchip_state() callback for the IO-APIC irq chip. The
callback is invoked from free_irq() via __synchronize_hardirq(). Check the
remote IRR bit of the interrupt and return 'in flight' if it is set and the
interrupt is configured in level mode. For edge mode the remote IRR has no
meaning.

As this is only meaningful for level triggered interrupts this won't cure
the potential spurious interrupt warning for edge triggered interrupts, but
the edge trigger case does not result in stale hardware state. This has to
be addressed at the vector/interrupt entry level seperately.

Fixes: 464d1230 ("x86/vector: Switch IOAPIC to global reservation mode")
Reported-by: default avatarRobert Hodaszi <Robert.Hodaszi@digi.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/20190628111440.370295517@linutronix.deSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      557f2d49
    • Thomas Gleixner's avatar
      genirq: Add optional hardware synchronization for shutdown · b9926c40
      Thomas Gleixner authored 
      commit 62e04686 upstream.

free_irq() ensures that no hardware interrupt handler is executing on a
different CPU before actually releasing resources and deactivating the
interrupt completely in a domain hierarchy.

But that does not catch the case where the interrupt is on flight at the
hardware level but not yet serviced by the target CPU. That creates an
interesing race condition:

   CPU 0                  CPU 1               IRQ CHIP

                                              interrupt is raised
                                              sent to CPU1
			  Unable to handle
			  immediately
			  (interrupts off,
			   deep idle delay)
   mask()
   ...
   free()
     shutdown()
     synchronize_irq()
     release_resources()
                          do_IRQ()
                            -> resources are not available

That might be harmless and just trigger a spurious interrupt warning, but
some interrupt chips might get into a wedged state.

Utilize the existing irq_get_irqchip_state() callback for the
synchronization in free_irq().

synchronize_hardirq() is not using this mechanism as it might actually
deadlock unter certain conditions, e.g. when called with interrupts
disabled and the target CPU is the one on which the synchronization is
invoked. synchronize_irq() uses it because that function cannot be called
from non preemtible contexts as it might sleep.

No functional change intended and according to Marc the existing GIC
implementations where the driver supports the callback should be able
to cope with that core change. Famous last words.

Fixes: 464d1230 ("x86/vector: Switch IOAPIC to global reservation mode")
Reported-by: default avatarRobert Hodaszi <Robert.Hodaszi@digi.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Tested-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/20190628111440.279463375@linutronix.deSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b9926c40
    • Thomas Gleixner's avatar
      genirq: Fix misleading synchronize_irq() documentation · cd022296
      Thomas Gleixner authored 
      commit 1d21f2af upstream.

The function might sleep, so it cannot be called from interrupt
context. Not even with care.
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/20190628111440.189241552@linutronix.deSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      cd022296
    • Thomas Gleixner's avatar
      genirq: Delay deactivation in free_irq() · 284f5105
      Thomas Gleixner authored 
      commit 4001d8e8 upstream.

When interrupts are shutdown, they are immediately deactivated in the
irqdomain hierarchy. While this looks obviously correct there is a subtle
issue:

There might be an interrupt in flight when free_irq() is invoking the
shutdown. This is properly handled at the irq descriptor / primary handler
level, but the deactivation might completely disable resources which are
required to acknowledge the interrupt.

Split the shutdown code and deactivate the interrupt after synchronization
in free_irq(). Fixup all other usage sites where this is not an issue to
invoke the combined shutdown_and_deactivate() function instead.

This still might be an issue if the interrupt in flight servicing is
delayed on a remote CPU beyond the invocation of synchronize_irq(), but
that cannot be handled at that level and needs to be handled in the
synchronize_irq() context.

Fixes: f8264e34 ("irqdomain: Introduce new interfaces to support hierarchy irqdomains")
Reported-by: default avatarRobert Hodaszi <Robert.Hodaszi@digi.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/20190628111440.098196390@linutronix.deSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      284f5105
    • Vinod Koul's avatar
      linux/kernel.h: fix overflow for DIV_ROUND_UP_ULL · cbf12566
      Vinod Koul authored 
      [ Upstream commit 8f9fab48 ]

DIV_ROUND_UP_ULL adds the two arguments and then invokes
DIV_ROUND_DOWN_ULL.  But on a 32bit system the addition of two 32 bit
values can overflow.  DIV_ROUND_DOWN_ULL does it correctly and stashes
the addition into a unsigned long long so cast the result to unsigned
long long here to avoid the overflow condition.

[akpm@linux-foundation.org: DIV_ROUND_UP_ULL must be an rval]
Link: http://lkml.kernel.org/r/20190625100518.30753-1-vkoul@kernel.orgSigned-off-by: default avatarVinod Koul <vkoul@kernel.org>
Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      cbf12566
    • Andrea Arcangeli's avatar
      fork,memcg: alloc_thread_stack_node needs to set tsk->stack · e97fe6ea
      Andrea Arcangeli authored 
      [ Upstream commit 1bf4580e ]

Commit 5eed6f1d ("fork,memcg: fix crash in free_thread_stack on
memcg charge fail") corrected two instances, but there was a third
instance of this bug.

Without setting tsk->stack, if memcg_charge_kernel_stack fails, it'll
execute free_thread_stack() on a dangling pointer.

Enterprise kernels are compiled with VMAP_STACK=y so this isn't
critical, but custom VMAP_STACK=n builds should have some performance
advantage, with the drawback of risking to fail fork because compaction
didn't succeed.  So as long as VMAP_STACK=n is a supported option it's
worth fixing it upstream.

Link: http://lkml.kernel.org/r/20190619011450.28048-1-aarcange@redhat.com
Fixes: 9b6f7e16 ("mm: rework memcg kernel stack accounting")
Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
Reviewed-by: default avatarRik van Riel <riel@surriel.com>
Acked-by: default avatarRoman Gushchin <guro@fb.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      e97fe6ea
    • Yafang Shao's avatar
      mm/oom_kill.c: fix uninitialized oc->constraint · 1451f564
      Yafang Shao authored 
      [ Upstream commit 432b1de0 ]

In dump_oom_summary() oc->constraint is used to show oom_constraint_text,
but it hasn't been set before.  So the value of it is always the default
value 0.  We should inititialize it before.

Bellow is the output when memcg oom occurs,

before this patch:
  oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null), cpuset=/,mems_allowed=0,oom_memcg=/foo,task_memcg=/foo,task=bash,pid=7997,uid=0

after this patch:
  oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null), cpuset=/,mems_allowed=0,oom_memcg=/foo,task_memcg=/foo,task=bash,pid=13681,uid=0

Link: http://lkml.kernel.org/r/1560522038-15879-1-git-send-email-laoar.shao@gmail.com
Fixes: ef8444ea ("mm, oom: reorganize the oom report in dump_header")
Signed-off-by: default avatarYafang Shao <laoar.shao@gmail.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Wind Yu <yuzhoujian@didichuxing.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      1451f564
    • Nicolas Boichat's avatar
      pinctrl: mediatek: Update cur_mask in mask/mask ops · 056432be
      Nicolas Boichat authored 
      [ Upstream commit 9d957a95 ]

During suspend/resume, mtk_eint_mask may be called while
wake_mask is active. For example, this happens if a wake-source
with an active interrupt handler wakes the system:
irq/pm.c:irq_pm_check_wakeup would disable the interrupt, so
that it can be handled later on in the resume flow.

However, this may happen before mtk_eint_do_resume is called:
in this case, wake_mask is loaded, and cur_mask is restored
from an older copy, re-enabling the interrupt, and causing
an interrupt storm (especially for level interrupts).

Step by step, for a line that has both wake and interrupt enabled:
 1. cur_mask[irq] = 1; wake_mask[irq] = 1; EINT_EN[irq] = 1 (interrupt
    enabled at hardware level)
 2. System suspends, resumes due to that line (at this stage EINT_EN
    == wake_mask)
 3. irq_pm_check_wakeup is called, and disables the interrupt =>
    EINT_EN[irq] = 0, but we still have cur_mask[irq] = 1
 4. mtk_eint_do_resume is called, and restores EINT_EN = cur_mask, so
    it reenables EINT_EN[irq] = 1 => interrupt storm as the driver
    is not yet ready to handle the interrupt.

This patch fixes the issue in step 3, by recording all mask/unmask
changes in cur_mask. This also avoids the need to read the current
mask in eint_do_suspend, and we can remove mtk_eint_chip_read_mask
function.

The interrupt will be re-enabled properly later on, sometimes after
mtk_eint_do_resume, when the driver is ready to handle it.

Fixes: 58a5e1b6 ("pinctrl: mediatek: Implement wake handler and suspend resume")
Signed-off-by: default avatarNicolas Boichat <drinkcat@chromium.org>
Acked-by: default avatarSean Wang <sean.wang@kernel.org>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
      056432be
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