linux.git/drivers/clocksource, branch v5.16

clocksource/drivers/arm_arch_timer: Force inlining of erratum_set_next_event_generic()

2021-12-10T16:47:00+00:00

With some specific kernel configuration and Clang, the kernel fails
to like with something like:

ld.lld: error: undefined symbol: __compiletime_assert_200
>>> referenced by arch_timer.h:156 (./arch/arm64/include/asm/arch_timer.h:156)
>>>               clocksource/arm_arch_timer.o:(erratum_set_next_event_generic) in archive drivers/built-in.a

ld.lld: error: undefined symbol: __compiletime_assert_197
>>> referenced by arch_timer.h:133 (./arch/arm64/include/asm/arch_timer.h:133)
>>>               clocksource/arm_arch_timer.o:(erratum_set_next_event_generic) in archive drivers/built-in.a
make: *** [Makefile:1161: vmlinux] Error 1

These are due to the BUILD_BUG() macros contained in the low-level
accessors (arch_timer_reg_{write,read}_cp15) being emitted, as the
access type wasn't known at compile time.

Fix this by making erratum_set_next_event_generic() __force_inline,
resulting in the 'access' parameter to be resolved at compile time,
similarly to what is already done for set_next_event().

Fixes: 4775bc63f880 ("Add build-time guards for unhandled register accesses")
Reported-by: Greg Kroah-Hartman 
Signed-off-by: Marc Zyngier 
Cc: Mark Rutland 
Cc: Daniel Lezcano 
Cc: Sami Tolvanen 
Cc: Nick Desaulniers 
Tested-by: Sami Tolvanen 
Reviewed-by: Nathan Chancellor 
Tested-by: Nathan Chancellor 
Link: https://lore.kernel.org/r/20211117113532.3895208-1-maz@kernel.org
Signed-off-by: Daniel Lezcano

clocksource/drivers/dw_apb_timer_of: Fix probe failure

2021-12-10T16:46:54+00:00

The driver refuses to probe with -EINVAL since the commit 5d9814df0aec
("clocksource/drivers/dw_apb_timer_of: Add error handling if no clock
available").

Before the driver used to probe successfully if either "clock-freq" or
"clock-frequency" properties has been specified in the device tree.

That commit changed

if (A && B)
	panic("No clock nor clock-frequency property");

into

if (!A && !B)
	return 0;

That's a bug: the reverse of `A && B` is '!A || !B', not '!A && !B'

Signed-off-by: Vadim V. Vlasov 
Signed-off-by: Alexey Sheplyakov 
Fixes: 5d9814df0aec56a6 ("clocksource/drivers/dw_apb_timer_of: Add error handling if no clock available").
Cc: Daniel Lezcano 
Cc: Dinh Nguyen 
Cc: Thomas Gleixner 
Cc: Vadim V. Vlasov 
Acked-by: Dinh Nguyen 
Link: https://lore.kernel.org/r/20211109153401.157491-1-asheplyakov@basealt.ru
Signed-off-by: Daniel Lezcano

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2021-11-02T18:24:14+00:00

Pull KVM updates from Paolo Bonzini:
 "ARM:

   - More progress on the protected VM front, now with the full fixed
     feature set as well as the limitation of some hypercalls after
     initialisation.

   - Cleanup of the RAZ/WI sysreg handling, which was pointlessly
     complicated

   - Fixes for the vgic placement in the IPA space, together with a
     bunch of selftests

   - More memcg accounting of the memory allocated on behalf of a guest

   - Timer and vgic selftests

   - Workarounds for the Apple M1 broken vgic implementation

   - KConfig cleanups

   - New kvmarm.mode=none option, for those who really dislike us

  RISC-V:

   - New KVM port.

  x86:

   - New API to control TSC offset from userspace

   - TSC scaling for nested hypervisors on SVM

   - Switch masterclock protection from raw_spin_lock to seqcount

   - Clean up function prototypes in the page fault code and avoid
     repeated memslot lookups

   - Convey the exit reason to userspace on emulation failure

   - Configure time between NX page recovery iterations

   - Expose Predictive Store Forwarding Disable CPUID leaf

   - Allocate page tracking data structures lazily (if the i915 KVM-GT
     functionality is not compiled in)

   - Cleanups, fixes and optimizations for the shadow MMU code

  s390:

   - SIGP Fixes

   - initial preparations for lazy destroy of secure VMs

   - storage key improvements/fixes

   - Log the guest CPNC

  Starting from this release, KVM-PPC patches will come from Michael
  Ellerman's PPC tree"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (227 commits)
  RISC-V: KVM: fix boolreturn.cocci warnings
  RISC-V: KVM: remove unneeded semicolon
  RISC-V: KVM: Fix GPA passed to __kvm_riscv_hfence_gvma_xyz() functions
  RISC-V: KVM: Factor-out FP virtualization into separate sources
  KVM: s390: add debug statement for diag 318 CPNC data
  KVM: s390: pv: properly handle page flags for protected guests
  KVM: s390: Fix handle_sske page fault handling
  KVM: x86: SGX must obey the KVM_INTERNAL_ERROR_EMULATION protocol
  KVM: x86: On emulation failure, convey the exit reason, etc. to userspace
  KVM: x86: Get exit_reason as part of kvm_x86_ops.get_exit_info
  KVM: x86: Clarify the kvm_run.emulation_failure structure layout
  KVM: s390: Add a routine for setting userspace CPU state
  KVM: s390: Simplify SIGP Set Arch handling
  KVM: s390: pv: avoid stalls when making pages secure
  KVM: s390: pv: avoid stalls for kvm_s390_pv_init_vm
  KVM: s390: pv: avoid double free of sida page
  KVM: s390: pv: add macros for UVC CC values
  s390/mm: optimize reset_guest_reference_bit()
  s390/mm: optimize set_guest_storage_key()
  s390/mm: no need for pte_alloc_map_lock() if we know the pmd is present
  ...

Merge tag 'timers-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2021-11-01T20:44:55+00:00

Pull timer updates from Thomas Gleixner:
 "Time, timers and timekeeping updates:

   - No core updates

   - No new clocksource/event driver

   - A large rework of the ARM architected timer driver to prepare for
     the support of the upcoming ARMv8.6 support

   - Fix Kconfig options for Exynos MCT, Samsung PWM and TI DM timers

   - Address a namespace collison in the ARC sp804 timer driver"

* tag 'timers-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/timer-ti-dm: Select TIMER_OF
  clocksource/drivers/exynosy: Depend on sub-architecture for Exynos MCT and Samsung PWM
  clocksource/drivers/arch_arm_timer: Move workaround synchronisation around
  clocksource/drivers/arm_arch_timer: Fix masking for high freq counters
  clocksource/drivers/arm_arch_timer: Drop unnecessary ISB on CVAL programming
  clocksource/drivers/arm_arch_timer: Remove any trace of the TVAL programming interface
  clocksource/drivers/arm_arch_timer: Work around broken CVAL implementations
  clocksource/drivers/arm_arch_timer: Advertise 56bit timer to the core code
  clocksource/drivers/arm_arch_timer: Move MMIO timer programming over to CVAL
  clocksource/drivers/arm_arch_timer: Fix MMIO base address vs callback ordering issue
  clocksource/drivers/arm_arch_timer: Move drop _tval from erratum function names
  clocksource/drivers/arm_arch_timer: Move system register timer programming over to CVAL
  clocksource/drivers/arm_arch_timer: Extend write side of timer register accessors to u64
  clocksource/drivers/arm_arch_timer: Drop CNT*_TVAL read accessors
  clocksource/arm_arch_timer: Add build-time guards for unhandled register accesses
  clocksource/drivers/arc_timer: Eliminate redefined macro error

clocksource/drivers/timer-ti-dm: Select TIMER_OF

2021-10-21T12:18:53+00:00

When building OMAP_DM_TIMER without TIMER_OF, there are orphan sections
due to the use of TIMER_OF_DELCARE() without CONFIG_TIMER_OF. Select
CONFIG_TIMER_OF when enaling OMAP_DM_TIMER:

arm-linux-gnueabi-ld: warning: orphan section `__timer_of_table' from `drivers/clocksource/timer-ti-dm-systimer.o' being placed in section `__timer_of_table'

Reported-by: kernel test robot 
Link: https://lore.kernel.org/lkml/202108282255.tkdt4ani-lkp@intel.com/
Cc: Tony Lindgren 
Cc: Daniel Lezcano 
Cc: Keerthy 
Cc: Sebastian Reichel 
Cc: Ladislav Michl 
Cc: Grygorii Strashko 
Cc: linux-omap@vger.kernel.org
Fixes: 52762fbd1c47 ("clocksource/drivers/timer-ti-dm: Add clockevent and clocksource support")
Signed-off-by: Kees Cook 
Acked-by: Tony Lindgren 
Link: https://lore.kernel.org/r/20210828175747.3777891-1-keescook@chromium.org
Signed-off-by: Daniel Lezcano

clocksource/drivers/exynosy: Depend on sub-architecture for Exynos MCT and Samsung PWM

2021-10-21T10:54:28+00:00

The Exynos MCT and Samsung PWM Timer clocksource drivers are not usable
on anything else than Samsung Exynos, S3C or S5P SoC platforms.  These
are integral parts of a SoC.  Even though the drivers are not user
selectable, still document the hardware architecture explicitly with
depends on ARCH_EXYNOS and others.  This also serves a purpose of
documenting use-case, if someone ever wonders whether to select the
driver for his platform.  No functional change, because drivers are
already selected by the platform described in depends. We follow similar
approach also for other SoC-specific drivers.

Signed-off-by: Krzysztof Kozlowski 
Link: https://lore.kernel.org/r/20211021063500.39314-1-krzysztof.kozlowski@canonical.com
Signed-off-by: Daniel Lezcano

Merge branch 'timers/drivers/armv8.6_arch_timer' into timers/drivers/next

2021-10-19T08:07:28+00:00

The branch is a stable branch shared with ARM maintainers for the
first 13th patches of the series:

It is based on v5.14-rc3.

As stated by the changelog:

" [... ] enabling ARMv8.6 support for timer subsystem, and was prompted by a
discussion with Oliver around the fact that an ARMv8.6 implementation
must have a 1GHz counter, which leads to a number of things to break
in the timer code:

- the counter rollover can come pretty quickly as we only advertise a
  56bit counter,
- the maximum timer delta can be remarkably small, as we use the
  countdown interface which is limited to 32bit...

Thankfully, there is a way out: we can compute the minimal width of
the counter based on the guarantees that the architecture gives us,
and we can use the 64bit comparator interface instead of the countdown
to program the timer.

Finally, we start making use of the ARMv8.6 ECV features by switching
accesses to the counters to a self-synchronising register, removing
the need for an ISB. Hopefully, implementations will *not* just stick
an invisible ISB there...

A side effect of the switch to CVAL is that XGene-1 breaks. I have
added a workaround to keep it alive.

I have added Oliver's original patch[0] to the series and tweaked a
couple of things. Blame me if I broke anything.

The whole things has been tested on Juno (sysreg + MMIO timers),
XGene-1 (broken sysreg timers), FVP (FEAT_ECV, CNT*CTSS_EL0).
"

Link: https://lore.kernel.org/r/20211017124225.3018098-1-maz@kernel.org
Signed-off-by: Daniel Lezcano

clocksource/drivers/arm_arch_timer: Fix masking for high freq counters

2021-10-18T07:20:02+00:00

Unfortunately, the architecture provides no means to determine the bit
width of the system counter. However, we do know the following from the
specification:

 - the system counter is at least 56 bits wide
 - Roll-over time of not less than 40 years

To date, the arch timer driver has depended on the first property,
assuming any system counter to be 56 bits wide and masking off the rest.
However, combining a narrow clocksource mask with a high frequency
counter could result in prematurely wrapping the system counter by a
significant margin. For example, a 56 bit wide, 1GHz system counter
would wrap in a mere 2.28 years!

This is a problem for two reasons: v8.6+ implementations are required to
provide a 64 bit, 1GHz system counter. Furthermore, before v8.6,
implementers may select a counter frequency of their choosing.

Fix the issue by deriving a valid clock mask based on the second
property from above. Set the floor at 56 bits, since we know no system
counter is narrower than that.

[maz: fixed width computation not to lose the last bit, added
      max delta generation for the timer]

Suggested-by: Marc Zyngier 
Signed-off-by: Oliver Upton 
Reviewed-by: Linus Walleij 
Signed-off-by: Marc Zyngier 
Link: https://lore.kernel.org/r/20210807191428.3488948-1-oupton@google.com
Link: https://lore.kernel.org/r/20211017124225.3018098-13-maz@kernel.org
Signed-off-by: Daniel Lezcano

clocksource/drivers/arm_arch_timer: Remove any trace of the TVAL programming interface

2021-10-17T19:47:39+00:00

TVAL usage is now long gone, get rid of the leftovers.

Signed-off-by: Marc Zyngier 
Link: https://lore.kernel.org/r/20211017124225.3018098-11-maz@kernel.org
Signed-off-by: Daniel Lezcano

clocksource/drivers/arm_arch_timer: Work around broken CVAL implementations

2021-10-17T19:47:31+00:00

The Applied Micro XGene-1 SoC has a busted implementation of the
CVAL register: it looks like it is based on TVAL instead of the
other way around. The net effect of this implementation blunder
is that the maximum deadline you can program in the timer is
32bit wide.

Use a MIDR check to notice the broken CPU, and reduce the width
of the timer to 32bit.

Signed-off-by: Marc Zyngier 
Link: https://lore.kernel.org/r/20211017124225.3018098-10-maz@kernel.org
Signed-off-by: Daniel Lezcano