linux-stable.git/arch/arm64/include/asm/arch_timer.h, branch linux-4.9.y Linux kernel stable tree arm64: arch_timer: Add erratum handler for CPU-specific capability 2022-04-12T05:52:14+00:00 Marc Zyngier marc.zyngier@arm.com 2022-04-06T16:45:18+00:00 ba072295630fece57622f60b73756064bbaee26e commit 0064030c6fd4ca6cfab42de037b2a89445beeead upstream. Should we ever have a workaround for an erratum that is detected using a capability and affecting a particular CPU, it'd be nice to have a way to probe them directly. Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 0064030c6fd4ca6cfab42de037b2a89445beeead upstream.

Should we ever have a workaround for an erratum that is detected using
a capability and affecting a particular CPU, it'd be nice to have
a way to probe them directly.

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arm64: arch_timer: Add infrastructure for multiple erratum detection methods 2022-04-12T05:52:14+00:00 Marc Zyngier marc.zyngier@arm.com 2022-04-06T16:45:17+00:00 f4a88eb6b1785a3489c157d76b05aa74b407979b commit 651bb2e9dca6e6dbad3fba5f6e6086a23575b8b5 upstream. We're currently stuck with DT when it comes to handling errata, which is pretty restrictive. In order to make things more flexible, let's introduce an infrastructure that could support alternative discovery methods. No change in functionality. Acked-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> [ morse: Removed the changes to HiSilicon erratum 161010101, which isn't present in v4.9 ] Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 651bb2e9dca6e6dbad3fba5f6e6086a23575b8b5 upstream.

We're currently stuck with DT when it comes to handling errata, which
is pretty restrictive. In order to make things more flexible, let's
introduce an infrastructure that could support alternative discovery
methods. No change in functionality.

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
[ morse: Removed the changes to HiSilicon erratum 161010101, which isn't
  present in v4.9 ]
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
clocksource/drivers/arm_arch_timer: Introduce generic errata handling infrastructure 2022-04-12T05:52:14+00:00 Ding Tianhong dingtianhong@huawei.com 2022-04-06T16:45:16+00:00 7a48b35f0cd3174ef1654005c6e991a2c625f0d9 commit 16d10ef29f25aba923779234bb93a451b14d20e6 upstream. Currently we have code inline in the arch timer probe path to cater for Freescale erratum A-008585, complete with ifdeffery. This is a little ugly, and will get worse as we try to add more errata handling. This patch refactors the handling of Freescale erratum A-008585. Now the erratum is described in a generic arch_timer_erratum_workaround structure, and the probe path can iterate over these to detect errata and enable workarounds. This will simplify the addition and maintenance of code handling Hisilicon erratum 161010101. Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> [Mark: split patch, correct Kconfig, reword commit message] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 16d10ef29f25aba923779234bb93a451b14d20e6 upstream.

Currently we have code inline in the arch timer probe path to cater for
Freescale erratum A-008585, complete with ifdeffery. This is a little
ugly, and will get worse as we try to add more errata handling.

This patch refactors the handling of Freescale erratum A-008585. Now the
erratum is described in a generic arch_timer_erratum_workaround
structure, and the probe path can iterate over these to detect errata
and enable workarounds.

This will simplify the addition and maintenance of code handling
Hisilicon erratum 161010101.

Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
[Mark: split patch, correct Kconfig, reword commit message]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arm64: arch_timer: Work around QorIQ Erratum A-008585 2016-09-23T16:19:25+00:00 Scott Wood oss@buserror.net 2016-09-22T08:35:17+00:00 f6dc1576cd517440313c9551b6ffa3d7e389c7c7 Erratum A-008585 says that the ARM generic timer counter "has the potential to contain an erroneous value for a small number of core clock cycles every time the timer value changes". Accesses to TVAL (both read and write) are also affected due to the implicit counter read. Accesses to CVAL are not affected. The workaround is to reread TVAL and count registers until successive reads return the same value. Writes to TVAL are replaced with an equivalent write to CVAL. The workaround is to reread TVAL and count registers until successive reads return the same value, and when writing TVAL to retry until counter reads before and after the write return the same value. The workaround is enabled if the fsl,erratum-a008585 property is found in the timer node in the device tree. This can be overridden with the clocksource.arm_arch_timer.fsl-a008585 boot parameter, which allows KVM users to enable the workaround until a mechanism is implemented to automatically communicate this information. This erratum can be found on LS1043A and LS2080A. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Scott Wood <oss@buserror.net> [will: renamed read macro to reflect that it's not usually unstable] Signed-off-by: Will Deacon <will.deacon@arm.com> 
Erratum A-008585 says that the ARM generic timer counter "has the
potential to contain an erroneous value for a small number of core
clock cycles every time the timer value changes".  Accesses to TVAL
(both read and write) are also affected due to the implicit counter
read.  Accesses to CVAL are not affected.

The workaround is to reread TVAL and count registers until successive
reads return the same value.  Writes to TVAL are replaced with an
equivalent write to CVAL.

The workaround is to reread TVAL and count registers until successive reads
return the same value, and when writing TVAL to retry until counter
reads before and after the write return the same value.

The workaround is enabled if the fsl,erratum-a008585 property is found in
the timer node in the device tree.  This can be overridden with the
clocksource.arm_arch_timer.fsl-a008585 boot parameter, which allows KVM
users to enable the workaround until a mechanism is implemented to
automatically communicate this information.

This erratum can be found on LS1043A and LS2080A.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Scott Wood <oss@buserror.net>
[will: renamed read macro to reflect that it's not usually unstable]
Signed-off-by: Will Deacon <will.deacon@arm.com>
arm64: arch_timer: simplify accessors 2016-09-09T10:41:13+00:00 Mark Rutland mark.rutland@arm.com 2016-09-08T12:55:35+00:00 cd5f22d7967f613c49288256ce95b07eb910e2a9 A while back we added {read,write}_sysreg accessors to handle accesses to system registers, without the usual boilerplate asm volatile, temporary variable, etc. This patch makes use of these in the arm64 arch timer accessors to make the code shorter and clearer. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> 
A while back we added {read,write}_sysreg accessors to handle accesses
to system registers, without the usual boilerplate asm volatile,
temporary variable, etc.

This patch makes use of these in the arm64 arch timer accessors to make
the code shorter and clearer.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
arm64: fix missing linux/bug.h include in asm/arch_timer.h 2015-01-07T11:40:59+00:00 Paul Walmsley pwalmsley@nvidia.com 2015-01-06T00:38:41+00:00 082471a8efe1a91d4e44abec202d9e3067dcec91 On next-20150105, defconfig compilation breaks with: ./arch/arm64/include/asm/arch_timer.h:112:2: error: implicit declaration of function ‘BUG’ [-Werror=implicit-function-declaration] Fix by including linux/bug.h, where the BUG macro is defined. This second version incorporates a comment from Mark Rutland <mark.rutland@arm.com> to keep the includes in alphabetical order by filename. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Paul Walmsley <pwalmsley@nvidia.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> 
On next-20150105, defconfig compilation breaks with:

./arch/arm64/include/asm/arch_timer.h:112:2: error: implicit declaration of function ‘BUG’ [-Werror=implicit-function-declaration]

Fix by including linux/bug.h, where the BUG macro is defined.

This second version incorporates a comment from Mark Rutland
<mark.rutland@arm.com> to keep the includes in alphabetical order
by filename.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Paul Walmsley <pwalmsley@nvidia.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
clocksource: arch_timer: Fix code to use physical timers when requested 2014-12-05T07:30:26+00:00 Sonny Rao sonnyrao@chromium.org 2014-11-24T07:02:44+00:00 0b46b8a718c6e90910a1b1b0fe797be3c167e186 This is a bug fix for using physical arch timers when the arch_timer_use_virtual boolean is false. It restores the arch_counter_get_cntpct() function after removal in 0d651e4e "clocksource: arch_timer: use virtual counters" We need this on certain ARMv7 systems which are architected like this: * The firmware doesn't know and doesn't care about hypervisor mode and we don't want to add the complexity of hypervisor there. * The firmware isn't involved in SMP bringup or resume. * The ARCH timer come up with an uninitialized offset between the virtual and physical counters. Each core gets a different random offset. * The device boots in "Secure SVC" mode. * Nothing has touched the reset value of CNTHCTL.PL1PCEN or CNTHCTL.PL1PCTEN (both default to 1 at reset) One example of such as system is RK3288 where it is much simpler to use the physical counter since there's nobody managing the offset and each time a core goes down and comes back up it will get reinitialized to some other random value. Fixes: 0d651e4e65e9 ("clocksource: arch_timer: use virtual counters") Cc: stable@vger.kernel.org Signed-off-by: Sonny Rao <sonnyrao@chromium.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Olof Johansson <olof@lixom.net> 
This is a bug fix for using physical arch timers when
the arch_timer_use_virtual boolean is false.  It restores the
arch_counter_get_cntpct() function after removal in

0d651e4e "clocksource: arch_timer: use virtual counters"

We need this on certain ARMv7 systems which are architected like this:

* The firmware doesn't know and doesn't care about hypervisor mode and
  we don't want to add the complexity of hypervisor there.

* The firmware isn't involved in SMP bringup or resume.

* The ARCH timer come up with an uninitialized offset between the
  virtual and physical counters.  Each core gets a different random
  offset.

* The device boots in "Secure SVC" mode.

* Nothing has touched the reset value of CNTHCTL.PL1PCEN or
  CNTHCTL.PL1PCTEN (both default to 1 at reset)

One example of such as system is RK3288 where it is much simpler to
use the physical counter since there's nobody managing the offset and
each time a core goes down and comes back up it will get reinitialized
to some other random value.

Fixes: 0d651e4e65e9 ("clocksource: arch_timer: use virtual counters")
Cc: stable@vger.kernel.org
Signed-off-by: Sonny Rao <sonnyrao@chromium.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
clocksource: arm_arch_timer: Consolidate arch_timer_evtstrm_enable 2014-09-28T23:59:26+00:00 Nathan Lynch nathan_lynch@mentor.com 2014-09-28T23:50:06+00:00 e1ce5c7adc735ce96a35806ca32ceb78e607a283 The arch_timer_evtstrm_enable hooks in arm and arm64 are substantially similar, the only difference being a CONFIG_COMPAT-conditional section which is relevant only for arm64. Copy the arm64 version to the driver, removing the arch-specific hooks. Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> 
The arch_timer_evtstrm_enable hooks in arm and arm64 are substantially
similar, the only difference being a CONFIG_COMPAT-conditional section
which is relevant only for arm64.  Copy the arm64 version to the
driver, removing the arch-specific hooks.

Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
clocksource: arm_arch_timer: Enable counter access for 32-bit ARM 2014-09-28T23:59:25+00:00 Nathan Lynch nathan_lynch@mentor.com 2014-09-28T23:50:06+00:00 8b8dde00347ef409b29abd97e5833ffdb4ed7508 The only difference between arm and arm64's implementations of arch_counter_set_user_access is that 32-bit ARM does not enable user access to the virtual counter. We want to enable this access for the 32-bit ARM VDSO, so copy the arm64 version to the driver itself, and remove the arch-specific implementations. Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> 
The only difference between arm and arm64's implementations of
arch_counter_set_user_access is that 32-bit ARM does not enable user
access to the virtual counter.  We want to enable this access for the
32-bit ARM VDSO, so copy the arm64 version to the driver itself, and
remove the arch-specific implementations.

Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
ARM64: arch_timer: add support to configure and enable event stream 2013-09-26T08:47:43+00:00 Sudeep KarkadaNagesha sudeep.karkadanagesha@arm.com 2013-08-13T14:57:53+00:00 46efe547aca8498d51b64460c02366ae4032ca32 This patch adds support for configuring the event stream frequency and enabling it. It also adds the hwcaps as well as compat-specific definitions to the user to detect this event stream feature. Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Will Deacon <will.deacon@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> 
This patch adds support for configuring the event stream frequency
and enabling it.

It also adds the hwcaps as well as compat-specific definitions to
the user to detect this event stream feature.

Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>