linux-toradex.git/drivers/clocksource/arm_arch_timer.c, branch v5.11-rc5

clocksource/drivers/arm_arch_timer: Correct fault programming of CNTKCTL_EL1.EVNTI

2020-12-05T18:34:04+00:00

ARM virtual counter supports event stream, it can only trigger an event
when the trigger bit (the value of CNTKCTL_EL1.EVNTI) of CNTVCT_EL0 changes,
so the actual period of event stream is 2^(cntkctl_evnti + 1). For example,
when the trigger bit is 0, then virtual counter trigger an event for every
two cycles.

While we're at it, rework the way we compute the trigger bit position
by making it more obvious that when bits [n:n-1] are both set (with n
being the most significant bit), we pick bit (n + 1).

Fixes: 037f637767a8 ("drivers: clocksource: add support for ARM architected timer event stream")
Suggested-by: Marc Zyngier 
Signed-off-by: Keqian Zhu 
Acked-by: Marc Zyngier 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20201204073126.6920-3-zhukeqian1@huawei.com

clocksource/drivers/arm_arch_timer: Use stable count reader in erratum sne

2020-12-05T18:33:55+00:00

In commit 0ea415390cd3 ("clocksource/arm_arch_timer: Use arch_timer_read_counter
to access stable counters"), we separate stable and normal count reader to omit
unnecessary overhead on systems that have no timer erratum.

However, in erratum_set_next_event_tval_generic(), count reader becomes normal
reader. This converts it to stable reader.

Fixes: 0ea415390cd3 ("clocksource/arm_arch_timer: Use arch_timer_read_counter to access stable counters")
Acked-by: Marc Zyngier 
Signed-off-by: Keqian Zhu 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20201204073126.6920-2-zhukeqian1@huawei.com

arm64: arch_timer: Disable the compat vdso for cores affected by ARM64_WORKAROUND_1418040

2020-07-08T20:57:51+00:00

ARM64_WORKAROUND_1418040 requires that AArch32 EL0 accesses to
the virtual counter register are trapped and emulated by the kernel.
This makes the vdso pretty pointless, and in some cases livelock
prone.

Provide a workaround entry that limits the vdso to 64bit tasks.

Signed-off-by: Marc Zyngier 
Acked-by: Mark Rutland 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200706163802.1836732-4-maz@kernel.org
Signed-off-by: Will Deacon

arm64: arch_timer: Allow an workaround descriptor to disable compat vdso

2020-07-08T20:57:51+00:00

As we are about to disable the vdso for compat tasks in some circumstances,
let's allow a workaround descriptor to express exactly that.

Signed-off-by: Marc Zyngier 
Acked-by: Mark Rutland 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200706163802.1836732-3-maz@kernel.org
Signed-off-by: Will Deacon

Merge branch 'timers/drivers/timer-ti' into timers/drivers/next

2020-05-22T22:01:13+00:00

drivers/clocksource/arm_arch_timer: Remove duplicate error message

2020-05-22T21:58:56+00:00

The function acpi_gtdt_init() prints a message in case of
error. Remove the error message after testing if the function fails,
otherwise it is a duplicate message.

Signed-off-by: Dejin Zheng 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20200429153559.21189-1-zhengdejin5@gmail.com

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2020-03-31T17:05:01+00:00

Pull arm64 updates from Catalin Marinas:
 "The bulk is in-kernel pointer authentication, activity monitors and
  lots of asm symbol annotations. I also queued the sys_mremap() patch
  commenting the asymmetry in the address untagging.

  Summary:

   - In-kernel Pointer Authentication support (previously only offered
     to user space).

   - ARM Activity Monitors (AMU) extension support allowing better CPU
     utilisation numbers for the scheduler (frequency invariance).

   - Memory hot-remove support for arm64.

   - Lots of asm annotations (SYM_*) in preparation for the in-kernel
     Branch Target Identification (BTI) support.

   - arm64 perf updates: ARMv8.5-PMU 64-bit counters, refactoring the
     PMU init callbacks, support for new DT compatibles.

   - IPv6 header checksum optimisation.

   - Fixes: SDEI (software delegated exception interface) double-lock on
     hibernate with shared events.

   - Minor clean-ups and refactoring: cpu_ops accessor,
     cpu_do_switch_mm() converted to C, cpufeature finalisation helper.

   - sys_mremap() comment explaining the asymmetric address untagging
     behaviour"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (81 commits)
  mm/mremap: Add comment explaining the untagging behaviour of mremap()
  arm64: head: Convert install_el2_stub to SYM_INNER_LABEL
  arm64: Introduce get_cpu_ops() helper function
  arm64: Rename cpu_read_ops() to init_cpu_ops()
  arm64: Declare ACPI parking protocol CPU operation if needed
  arm64: move kimage_vaddr to .rodata
  arm64: use mov_q instead of literal ldr
  arm64: Kconfig: verify binutils support for ARM64_PTR_AUTH
  lkdtm: arm64: test kernel pointer authentication
  arm64: compile the kernel with ptrauth return address signing
  kconfig: Add support for 'as-option'
  arm64: suspend: restore the kernel ptrauth keys
  arm64: __show_regs: strip PAC from lr in printk
  arm64: unwind: strip PAC from kernel addresses
  arm64: mask PAC bits of __builtin_return_address
  arm64: initialize ptrauth keys for kernel booting task
  arm64: initialize and switch ptrauth kernel keys
  arm64: enable ptrauth earlier
  arm64: cpufeature: handle conflicts based on capability
  arm64: cpufeature: Move cpu capability helpers inside C file
  ...

clocksource/drivers/arm_arch_timer: validate arch_timer_rate

2020-03-06T16:02:51+00:00

Using an arch timer with a frequency of less than 1MHz can potentially
result in incorrect functionality in systems that assume a reasonable
rate of the arch timer of 1 to 50MHz, described as typical in the
architecture specification.

Therefore, warn if the arch timer rate is below 1MHz, which is
considered atypical and worth emphasizing.

Suggested-by: Valentin Schneider 
Signed-off-by: Ionela Voinescu 
Acked-by: Marc Zyngier 
Cc: Marc Zyngier 
Cc: Mark Rutland 
Signed-off-by: Catalin Marinas

clocksource/drivers/arm_arch_timer: Fix vDSO clockmode when vDSO disabled

2020-02-25T21:08:39+00:00

The arm_arch_timer requires VDSO_CLOCKMODE_ARCHTIMER to be defined to
compile correctly. On ARM the vDSO can be disabled and when this is the
case the compilation ends prematurely with an error:

 $ make ARCH=arm multi_v7_defconfig
 $ ./scripts/config -d VDSO
 $ make

drivers/clocksource/arm_arch_timer.c:73:44: error:
‘VDSO_CLOCKMODE_ARCHTIMER’ undeclared here (not in a function)
  static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_ARCHTIMER;

Make the usage of VDSO_CLOCKMODE_ARCHTIMER depend on the VDSO enablement
and initialize the vdso clockmode variable with VDSO_CLOCKMODE_NONE
otherwise.

[ tglx: Match changelog and patch content. ]

Fixes: 5e3c6a312a09 ("ARM/arm64: vdso: Use common vdso clock mode storage")
Reported-by: Marek Szyprowski 
Signed-off-by: Vincenzo Frascino 
Signed-off-by: Thomas Gleixner 
Link: https://lkml.kernel.org/r/20200224151552.57274-1-vincenzo.frascino@arm.com

ARM/arm64: vdso: Use common vdso clock mode storage

2020-02-17T19:12:16+00:00

Convert ARM/ARM64 to the generic VDSO clock mode storage. This needs to
happen in one go as they share the clocksource driver.

Signed-off-by: Thomas Gleixner 
Tested-by: Vincenzo Frascino 
Reviewed-by: Vincenzo Frascino 
Link: https://lkml.kernel.org/r/20200207124403.363235229@linutronix.de