In preparation of selectively reinstating the timer enable quirk for Xen
that we removed in commit 411a373ed6 ("ArmPkg/TimerDxe: remove workaround
for KVM timer handling"), add a ArmGenericTimerReenableTimer() library
function to ArmGenericTimerCounterLib that we will populate for Xen only.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Julien Grall <julien.grall@arm.com>
Acked-by: Julien Grall <julien.grall@arm.com>
When we first ported EDK2 to KVM/arm, we implemented a workaround for
the quirky timer handling on the KVM side. This has been fixed in
Linux commit f120cd6533d2 ("KVM: arm/arm64: timer: Allow the timer to
control the active state") dated 23 June 2014, which was incorporated
into Linux release 4.3.
So almost 4 years later, it should be safe to drop this workaround on
the EDK2 side.
This reverts commit b1a633434d.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
If timer interrupt is level sensitive, reloading timer compare
register has a side effect of clearing GIC pending status, so a "ISB"
is needed to make sure this instruction is executed before enabling
CPU IRQ, or else we may get spurious timer interrupts.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Heyi Guo <heyi.guo@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
The generic timer driver only EOIs the timer interrupt if
the ISTATUS bit is set. This is completely fine if you pretend
that spurious interrupts do not exist. But as a matter of fact,
they do, and the first one will leave the interrupt activated
at the GIC level, making sure that no other interrupt can make
it anymore.
Making sure that each interrupt Ack is paired with an EOI is the
way to go. Oh, and enabling the interrupt each time it is taken
is completely pointless. We entered this function for a good
reason...
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
The generic timer support libraries call the actual system register
accessor function via a single pair of functions ArmArchTimerReadReg()
and ArmArchTimerWriteReg(), which take an enum argument to identify
the register, and return output values by pointer reference.
Since these functions are never called with a non-immediate argument,
we can simply replace each invocation with the underlying system register
accessor instead. This is mostly functionally equivalent, with the
exception of the bounds check for the enum (which is pointless given the
fact that we never pass a variable), the check for the presence of the
architected timer (which only makes sense for ARMv7, but is highly unlikely
to vary between platforms that are similar enough to run the same firmware
image), and a check for enum values that refer to the HYP view of the timer,
which we never referred to anywhere in the code in the first place.
So get rid of the middle man, and update the ArmGenericTimerPhyCounterLib
and ArmGenericTimerVirtCounterLib implementations to call the system
register accessors directly.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Tested-by: Ryan Harkin <ryan.harkin@linaro.org>
The DT binding for the ARM generic timer describes the secure,
non-secure, virtual and hypervisor timer interrupts, respectively.
However, under virtualization, only the virtual timer is usable, and
the device tree may omit the hypervisor timer interrupt. (Other timer
interrupts cannot be omitted simply due to the fact that the virtual
timer is listed third)
Contributed-under: TianoCore Contribution Agreement 1.0
Reviewed-by: Olivier Martin <olivier.martin@arm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16953 6f19259b-4bc3-4df7-8a09-765794883524
KVM on ARM currently masks the timer interrupt on the timer side when
delivering an interrupt to the guest. This itself is a workaround for an
issue where the interrupt is reraised and trapped by the host as soon as
the guest is entered, resulting in the guest being starved.
Work around this by calling ArmGenericTimerEnable () after servicing each
interrupt. The virtual version of ArmGenericTimerCounterLib will then
make sure to unmask the interrupt again.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-By: Olivier Martin <olivier.martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16144 6f19259b-4bc3-4df7-8a09-765794883524
The PCD gArmTokenSpaceGuid.PcdArmArchTimerFreqInHz is used in the
SEC phase (if applicable) to write the platform's counter frequency
to the CNTFRQ system register, as this needs to be done by the highest
exception level implemented.
Under virtualization, we should be able to rely on the host to have
initialized this register to a sane value, as we run at EL1 and only
use the virtual timer, so the PcdArmArchTimerFreqInHz PCD has little
meaning here.
So in either case, by the time we enter the DXE phase, we can use the
CNTFRQ system register to read the frequency instead of looking at the
PCD.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Olivier Martin <olivier.martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16090 6f19259b-4bc3-4df7-8a09-765794883524
Move TimerDxe and ArmArchTimerLib to ArmGenericTimerCounterLib, and update all
platforms to select the physical counter instance they have been using
implicitly all along.
Contributed-under: TianoCore Contribution Agreement 1.0
Acked-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-By: Olivier Martin <olivier.martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16078 6f19259b-4bc3-4df7-8a09-765794883524
The ArmArchTimerLib.h include file is not directly related to the TimerLib
instance ArmArchTimerLib, so the name is confusing. Rename to ArmArchTimer.h
instead.
Contributed-under: TianoCore Contribution Agreement 1.0
Acked-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-By: Olivier Martin <olivier.martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16073 6f19259b-4bc3-4df7-8a09-765794883524
Prior to this change, the TimerPeriod was re-initialize at the
end of the interrupt handling with the value of the period.
It means the real timer period was: Timer Interrupt Processing
time + Timer Period
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15923 6f19259b-4bc3-4df7-8a09-765794883524
Prior to this change the period was restored to the default period.
This change restores the latest 'set period'.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15922 6f19259b-4bc3-4df7-8a09-765794883524
Prior to this change the frequency was rounded to 1Mhz.
This change rounds the timer frequency to 1KHz.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15921 6f19259b-4bc3-4df7-8a09-765794883524
- Registering a interrupt handler implicitly enables said interrupt. This
is in the UEFI Spec. No need to enable the interrupts a second time.
- Make sure the Timer is completely disabled before configuring it. Only
enable after configuration is complete.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14433 6f19259b-4bc3-4df7-8a09-765794883524
Ard Biesheuvel
Heyi Guo
Marc Zyngier
Olivier Martin
Ronald Cron
Harry Liebel
oliviermartin