arm64: Add CNTFRQ_EL0 handler

[dann frazier]

[Impact]
Userspace reads of CNTVCT_EL0 are broken on HiSilicon D05 systems, which breaks some applications such as OpenMPI.

[Test Case]
#include <sys/times.h>
#include <stdio.h>

int main(int argc, char *argv[])
{
   unsigned int freq;
   __asm__ __volatile__ ("mrs %0, CNTFRQ_EL0" : "=r" (freq));
   printf("freq %d\n",freq);
    return (int)freq;
}

==================================
gcc test.c test
./test

This will report an illegal instruction, but should print a frequency value.

[Regression Risk]
The best way we can minimize risk is to verify on both a system that has an errata handler for the timer (D05) and a system that doesn't. We should then be exercising both code paths.

I have regression tested this, using the above test case, on the HP m400, the QDT Centriq 2400, and a Cavium ThunderX CRB.

[Thadeu Lima de Souza Cascardo (cascardo)]

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-zesty' to 'verification-done-zesty'. If the problem still exists, change the tag 'verification-needed-zesty' to 'verification-failed-zesty'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[dann frazier (dannf)]

On a HiSilicon D05 system:

ubuntu@ubuntu:~$ cat /proc/version
Linux version 4.10.0-22-generic (buildd@bos01-arm64-038) (gcc version 6.3.0 20170406 (Ubuntu/Linaro 6.3.0-12ubuntu2) ) #24-Ubuntu SMP Mon May 22 17:43:39 UTC 2017
ubuntu@ubuntu:~$ ./test
freq 50000000

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.10.0-22.24

---------------
linux (4.10.0-22.24) zesty; urgency=low

  * linux: 4.10.0-22.24 -proposed tracker (LP: #1691146)

  * Fix NVLINK2 TCE route (LP: #1690155)
    - powerpc/powernv: Fix TCE kill on NVLink2

  * CVE-2017-0605
    - tracing: Use strlcpy() instead of strcpy() in __trace_find_cmdline()

  * perf: qcom: Add L3 cache PMU driver (LP: #1689856)
    - [Config] CONFIG_QCOM_L3_PMU=y
    - perf: qcom: Add L3 cache PMU driver

  * No PMU support for ACPI-based arm64 systems (LP: #1689661)
    - drivers/perf: arm_pmu: rework per-cpu allocation
    - drivers/perf: arm_pmu: manage interrupts per-cpu
    - drivers/perf: arm_pmu: split irq request from enable
    - drivers/perf: arm_pmu: remove pointless PMU disabling
    - drivers/perf: arm_pmu: define armpmu_init_fn
    - drivers/perf: arm_pmu: fold init into alloc
    - drivers/perf: arm_pmu: factor out pmu registration
    - drivers/perf: arm_pmu: simplify cpu_pmu_request_irqs()
    - drivers/perf: arm_pmu: handle no platform_device
    - drivers/perf: arm_pmu: rename irq request/free functions
    - drivers/perf: arm_pmu: split cpu-local irq request/free
    - drivers/perf: arm_pmu: move irq request/free into probe
    - drivers/perf: arm_pmu: split out platform device probe logic
    - arm64: add function to get a cpu's MADT GICC table
    - [Config] CONFIG_ARM_PMU_ACPI=y
    - drivers/perf: arm_pmu: add ACPI framework
    - arm64: pmuv3: handle !PMUv3 when probing
    - arm64: pmuv3: use arm_pmu ACPI framework

  * [SRU][Zesty]QDF2400 kernel oops on ipmitool fru write 0 fru.bin
    (LP: #1689886)
    - ipmi: Fix kernel panic at ipmi_ssif_thread()

  * tty: pl011: fix earlycon work-around for QDF2400 erratum 44 (LP: #1689818)
    - tty: pl011: fix earlycon work-around for QDF2400 erratum 44
    - tty: pl011: use "qdf2400_e44" as the earlycon name for QDF2400 E44

  * kernel-wedge fails in artful due to leftover squashfs-modules d-i files
    (LP: #1688259)
    - Remove squashfs-modules files from d-i
    - [Config] as squashfs-modules is builtin kernel-image must Provides: it

  * arm64/ACPI support for SBSA watchdog (LP: #1688114)
    - clocksource: arm_arch_timer: clean up printk usage
    - clocksource: arm_arch_timer: rename type macros
    - clocksource: arm_arch_timer: rename the PPI enum
    - clocksource: arm_arch_timer: move enums and defines to header file
    - clocksource: arm_arch_timer: add a new enum for spi type
    - clocksource: arm_arch_timer: rework PPI selection
    - clocksource: arm_arch_timer: split dt-only rate handling
    - clocksource: arm_arch_timer: refactor arch_timer_needs_probing
    - clocksource: arm_arch_timer: move arch_timer_needs_of_probing into DT init
      call
    - clocksource: arm_arch_timer: add structs to describe MMIO timer
    - clocksource: arm_arch_timer: split MMIO timer probing.
    - [Config] CONFIG_ACPI_GTDT=y
    - acpi/arm64: Add GTDT table parse driver
    - clocksource: arm_arch_timer: simplify ACPI support code.
    - acpi/arm64: Add memory-mapped timer support in GTDT driver
    - clocksource: arm_arch_timer: add GTDT support for memory-mapped timer
    - acpi/arm64: Add SBS...