fix(cpus): workaround for Cortex-A710 erratum 3701772

Cortex-A710 erratum 3701772 that applies to all revisions <= r2p1
and is still Open.

The workaround is for EL3 software that performs context s

fix(cpus): workaround for Cortex-A710 erratum 3701772

Cortex-A710 erratum 3701772 that applies to all revisions <= r2p1
and is still Open.

The workaround is for EL3 software that performs context save/restore
on a change of Security state to use a value of SCR_EL3.NS when
accessing ICH_VMCR_EL2 that reflects the Security state that owns the
data being saved or restored.

SDEN documentation:
https://developer.arm.com/documentation/SDEN-1775101/latest/

Change-Id: I997c9cfaa75321f22b4f690c4d3f234c0b51c670
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>

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fix(cpus): workaround for accessing ICH_VMCR_EL2

When ICH_VMCR_EL2.VBPR1 is written in Secure state (SCR_EL3.NS==0)
and then subsequently read in Non-secure state (SCR_EL3.NS==1), a
wrong value migh

fix(cpus): workaround for accessing ICH_VMCR_EL2

When ICH_VMCR_EL2.VBPR1 is written in Secure state (SCR_EL3.NS==0)
and then subsequently read in Non-secure state (SCR_EL3.NS==1), a
wrong value might be returned. The same issue exists in the opposite way.

Adding workaround in EL3 software that performs context save/restore
on a change of Security state to use a value of SCR_EL3.NS when
accessing ICH_VMCR_EL2 that reflects the Security state that owns the
data being saved or restored. For example, EL3 software should set
SCR_EL3.NS to 1 when saving or restoring the value ICH_VMCR_EL2 for
Non-secure(or Realm) state. EL3 software should clear
SCR_EL3.NS to 0 when saving or restoring the value ICH_VMCR_EL2 for
Secure state.

SDEN documentation:
https://developer.arm.com/documentation/SDEN-1775101/latest/

Change-Id: I9f0403601c6346276e925f02eab55908b009d957
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>

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chore(docs): drop the "wfi" from `pwr_domain_pwr_down_wfi`

To allow for generic handling of a wakeup, this hook is no longer
expected to call wfi itself. Update the name everywhere to reflect this
e

chore(docs): drop the "wfi" from `pwr_domain_pwr_down_wfi`

To allow for generic handling of a wakeup, this hook is no longer
expected to call wfi itself. Update the name everywhere to reflect this
expectation so that future platform implementers don't get misled.

Change-Id: Ic33f0b6da74592ad6778fd802c2f0b85223af614
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>

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chore(psci): drop skip_wfi variable

There is now a convent place at the end of the function to jump to when
we shouldn't power down. This eliminates the need for skip_wfi.

Change-Id: I8d1a88c77463e

chore(psci): drop skip_wfi variable

There is now a convent place at the end of the function to jump to when
we shouldn't power down. This eliminates the need for skip_wfi.

Change-Id: I8d1a88c77463e8ee6765b185adbe3d23d9fce101
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>

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fix(cpus): avoid SME related loss of context on powerdown

Travis' and Gelas' TRMs tell us to disable SME (set PSTATE.{ZA, SM} to
0) when we're attempting to power down. What they don't tell us is th

fix(cpus): avoid SME related loss of context on powerdown

Travis' and Gelas' TRMs tell us to disable SME (set PSTATE.{ZA, SM} to
0) when we're attempting to power down. What they don't tell us is that
if this isn't done, the powerdown request will be rejected. On the
CPU_OFF path that's not a problem - we can force SVCR to 0 and be
certain the core will power off.

On the suspend to powerdown path, however, we cannot do this. The TRM
also tells us that the sequence could also be aborted on eg. GIC
interrupts. If this were to happen when we have overwritten SVCR to 0,
upon a return to the caller they would experience a loss of context. We
know that at least Linux may call into PSCI with SVCR != 0. One option
is to save the entire SME context which would be quite expensive just to
work around. Another option is to downgrade the request to a normal
suspend when SME was left on. This option is better as this is expected
to happen rarely enough to ignore the wasted power and we don't want to
burden the generic (correct) path with needless context management.

Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: I698fa8490ebf51461f6aa8bba84f9827c5c46ad4

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feat(psci): allow cores to wake up from powerdown

The simplistic view of a core's powerdown sequence is that power is
atomically cut upon calling `wfi`. However, it turns out that it has
lots to do

feat(psci): allow cores to wake up from powerdown

The simplistic view of a core's powerdown sequence is that power is
atomically cut upon calling `wfi`. However, it turns out that it has
lots to do - it has to talk to the interconnect to exit coherency, clean
caches, check for RAS errors, etc. These take significant amounts of
time and are certainly not atomic. As such there is a significant window
of opportunity for external events to happen. Many of these steps are
not destructive to context, so theoretically, the core can just "give
up" half way (or roll certain actions back) and carry on running. The
point in this sequence after which roll back is not possible is called
the point of no return.

One of these actions is the checking for RAS errors. It is possible for
one to happen during this lengthy sequence, or at least remain
undiscovered until that point. If the core were to continue powerdown
when that happens, there would be no (easy) way to inform anyone about
it. Rejecting the powerdown and letting software handle the error is the
best way to implement this.

Arm cores since at least the a510 have included this exact feature. So
far it hasn't been deemed necessary to account for it in firmware due to
the low likelihood of this happening. However, events like GIC wakeup
requests are much more probable. Older cores will powerdown and
immediately power back up when this happens. Travis and Gelas include a
feature similar to the RAS case above, called powerdown abandon. The
idea is that this will improve the latency to service the interrupt by
saving on work which the core and software need to do.

So far firmware has relied on the `wfi` being the point of no return and
if it doesn't explicitly detect a pending interrupt quite early on, it
will embark onto a sequence that it expects to end with shutdown. To
accommodate for it not being a point of no return, we must undo all of
the system management we did, just like in the warm boot entrypoint.

To achieve that, the pwr_domain_pwr_down_wfi hook must not be terminal.
Most recent platforms do some platform management and finish on the
standard `wfi`, followed by a panic or an endless loop as this is
expected to not return. To make this generic, any platform that wishes
to support wakeups must instead let common code call
`psci_power_down_wfi()` right after. Besides wakeups, this lets common
code handle powerdown errata better as well.

Then, the CPU_OFF case is simple - PSCI does not allow it to return. So
the best that can be done is to attempt the `wfi` a few times (the
choice of 32 is arbitrary) in the hope that the wakeup is transient. If
it isn't, the only choice is to panic, as the system is likely to be in
a bad state, eg. interrupts weren't routed away. The same applies for
SYSTEM_OFF, SYSTEM_RESET, and SYSTEM_RESET2. There the panic won't
matter as the system is going offline one way or another. The RAS case
will be considered in a separate patch.

Now, the CPU_SUSPEND case is more involved. First, to powerdown it must
wipe its context as it is not written on warm boot. But it cannot be
overwritten in case of a wakeup. To avoid the catch 22, save a copy that
will only be used if powerdown fails. That is about 500 bytes on the
stack so it hopefully doesn't tip anyone over any limits. In future that
can be avoided by having a core manage its own context.

Second, when the core wakes up, it must undo anything it did to prepare
for poweroff, which for the cores we care about, is writing
CPUPWRCTLR_EL1.CORE_PWRDN_EN. The least intrusive for the cpu library
way of doing this is to simply call the power off hook again and have
the hook toggle the bit. If in the future there need to be more complex
sequences, their direction can be advised on the value of this bit.

Third, do the actual "resume". Most of the logic is already there for
the retention suspend, so that only needs a small touch up to apply to
the powerdown case as well. The missing bit is the powerdown specific
state management. Luckily, the warmboot entrypoint does exactly that
already too, so steal that and we're done.

All of this is hidden behind a FEAT_PABANDON flag since it has a large
memory and runtime cost that we don't want to burden non pabandon cores
with.

Finally, do some function renaming to better reflect their purpose and
make names a little bit more consistent.

Change-Id: I2405b59300c2e24ce02e266f91b7c51474c1145f
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>

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refactor(cpus): undo errata mitigations

The workarounds introduced in the three patches starting at
888eafa00b99aa06b4ff688407336811a7ff439a assumed that any powerdown
request will be (forced to be)

refactor(cpus): undo errata mitigations

The workarounds introduced in the three patches starting at
888eafa00b99aa06b4ff688407336811a7ff439a assumed that any powerdown
request will be (forced to be) terminal. This assumption can no longer
be the case for new CPUs so there is a need to revisit these older
cores. Since we may wake up, we now need to respect the workaround's
recommendation that the workaround needs to be reverted on wakeup. So do
exactly that.

Introduce a new helper to toggle bits in assembly. This allows us to
call the workaround twice, with the first call setting the workaround
and second undoing it. This is also used for gelas' an travis' powerdown
routines. This is so the same function can be called again

Also fix the condition in the cpu helper macro as it was subtly wrong

Change-Id: Iff9e5251dc9d8670d085d88c070f78991955e7c3
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>

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feat(cpus): add sysreg_bit_toggle

Introduce a new helper to toggle bits in assembly. This allows us to
call the workaround twice, with the first call setting the workaround
and second undoing it. Th

feat(cpus): add sysreg_bit_toggle

Introduce a new helper to toggle bits in assembly. This allows us to
call the workaround twice, with the first call setting the workaround
and second undoing it. This allows the (errata) workaround functions to
be used to both apply and undo the mitigation.

This is applied to functions where the undo part will be required in
follow-up patches.

Change-Id: I058bad58f5949b2d5fe058101410e33b6be1b8ba
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>

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fix(simd): fix base register in fpregs_context_*

The fpregs_state_* macros require the base register
to point to the start of the simd_regs_t structure.
The fpregs_context_* functions were passing t

fix(simd): fix base register in fpregs_context_*

The fpregs_state_* macros require the base register
to point to the start of the simd_regs_t structure.
The fpregs_context_* functions were passing the
address incorrectly shifted by 512 bytes.

Signed-off-by: Andrei Homescu <ahomescu@google.com>
Change-Id: I757a26f8910c2ab648116e001e06baa3deb2eec4

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fix(security): apply SMCCC_ARCH_WORKAROUND_4 to affected cpus

This patch implements SMCCC_ARCH_WORKAROUND_4 and
allows discovery through SMCCC_ARCH_FEATURES.
This mechanism is enabled if CVE_2024_78

fix(security): apply SMCCC_ARCH_WORKAROUND_4 to affected cpus

This patch implements SMCCC_ARCH_WORKAROUND_4 and
allows discovery through SMCCC_ARCH_FEATURES.
This mechanism is enabled if CVE_2024_7881 [1] is enabled
by the platform. If CVE_2024_7881 mitigation
is implemented, the discovery call returns 0,
if not -1 (SMC_ARCH_CALL_NOT_SUPPORTED).

For more information about SMCCC_ARCH_WORKAROUND_4 [2], please
refer to the SMCCC Specification reference provided below.

[1]: https://developer.arm.com/Arm%20Security%20Center/Arm%20CPU%20Vulnerability%20CVE-2024-7881
[2]: https://developer.arm.com/documentation/den0028/latest

Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: I1b1ffaa1f806f07472fd79d5525f81764d99bc79

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fix(security): add CVE-2024-7881 mitigation to Cortex-X3

This patch mitigates CVE-2024-7881 [1] by setting CPUACTLR6_EL1[41] to 1
for Cortex-X3 CPU.

[1]: https://developer.arm.com/Arm%20Security%20

fix(security): add CVE-2024-7881 mitigation to Cortex-X3

This patch mitigates CVE-2024-7881 [1] by setting CPUACTLR6_EL1[41] to 1
for Cortex-X3 CPU.

[1]: https://developer.arm.com/Arm%20Security%20Center/Arm%20CPU%20Vulnerability%20CVE-2024-7881

Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: I410517d175a80fc6f459fa6ce5c30c0a38db9eaf

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fix(security): add CVE-2024-7881 mitigation to Neoverse-V3

This patch mitigates CVE-2024-7881 [1] by setting CPUACTLR6_EL1[41] to 1
for Neoverse-V3 CPU.

[1]: https://developer.arm.com/Arm%20Securit

fix(security): add CVE-2024-7881 mitigation to Neoverse-V3

This patch mitigates CVE-2024-7881 [1] by setting CPUACTLR6_EL1[41] to 1
for Neoverse-V3 CPU.

[1]: https://developer.arm.com/Arm%20Security%20Center/Arm%20CPU%20Vulnerability%20CVE-2024-7881

Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: Ib5c644895b8c76d3c7e8b5e6e98d7b9afef7f1ec

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fix(security): add CVE-2024-7881 mitigation to Neoverse-V2

This patch mitigates CVE-2024-7881 [1] by setting CPUACTLR6_EL1[41] to 1
for Neoverse-V2 CPU.

[1]: https://developer.arm.com/Arm%20Securit

fix(security): add CVE-2024-7881 mitigation to Neoverse-V2

This patch mitigates CVE-2024-7881 [1] by setting CPUACTLR6_EL1[41] to 1
for Neoverse-V2 CPU.

[1]: https://developer.arm.com/Arm%20Security%20Center/Arm%20CPU%20Vulnerability%20CVE-2024-7881

Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: I129814eb3494b287fd76a3f7dbc50f76553b2565

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fix(security): add CVE-2024-7881 mitigation to Cortex-X925

This patch mitigates CVE-2024-7881 [1] by setting CPUACTLR6_EL1[41] to 1
for Cortex-X925 CPU.

[1]: https://developer.arm.com/Arm%20Securit

fix(security): add CVE-2024-7881 mitigation to Cortex-X925

This patch mitigates CVE-2024-7881 [1] by setting CPUACTLR6_EL1[41] to 1
for Cortex-X925 CPU.

[1]: https://developer.arm.com/Arm%20Security%20Center/Arm%20CPU%20Vulnerability%20CVE-2024-7881

Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: I53e72e4dbc8937cea3c344a5ba04664c50a0792a

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fix(security): add CVE-2024-7881 mitigation to Cortex-X4

This patch mitigates CVE-2024-7881 [1] by setting CPUACTLR6_EL1[41] to 1
for Cortex-X4 CPU.

[1]: https://developer.arm.com/Arm%20Security%20

fix(security): add CVE-2024-7881 mitigation to Cortex-X4

This patch mitigates CVE-2024-7881 [1] by setting CPUACTLR6_EL1[41] to 1
for Cortex-X4 CPU.

[1]: https://developer.arm.com/Arm%20Security%20Center/Arm%20CPU%20Vulnerability%20CVE-2024-7881

Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: I0bec96d4f71a08a89c6612e272ecfb173f80da20

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fix(security): enable WORKAROUND_CVE_2024_7881 build option

This patch enables build option needed to include
support for CVE_2024_7881 [1] migitation.

[1]: https://developer.arm.com/Arm%20Security

fix(security): enable WORKAROUND_CVE_2024_7881 build option

This patch enables build option needed to include
support for CVE_2024_7881 [1] migitation.

[1]: https://developer.arm.com/Arm%20Security%20Center/Arm%20CPU%20Vulnerability%20CVE-2024-7881

Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: Id77f82a4dfaa4422729f7e3f2429f47cc90d9782

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Merge "feat(pmuv3): setup per world MDCR_EL3" into integration

feat(pmuv3): setup per world MDCR_EL3

MDCR_EL3 register will context switch across all worlds. Thus the pmuv3
init has to be part of context management initialization.

Change-Id: I10ef7a3071c0fc5c1

feat(pmuv3): setup per world MDCR_EL3

MDCR_EL3 register will context switch across all worlds. Thus the pmuv3
init has to be part of context management initialization.

Change-Id: I10ef7a3071c0fc5c11a93d3c9c2a95ec8c6493bf
Signed-off-by: Mateusz Sulimowicz <matsul@google.com>

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Merge changes I137f69be,Ia2e7168f,I0e569d12,I614272ec,Ib68293f2 into integration

* changes:
perf(psci): pass my_core_pos around instead of calling it repeatedly
refactor(psci): move timestamp co

Merge changes I137f69be,Ia2e7168f,I0e569d12,I614272ec,Ib68293f2 into integration

* changes:
perf(psci): pass my_core_pos around instead of calling it repeatedly
refactor(psci): move timestamp collection to psci_pwrdown_cpu
refactor(psci): factor common code out of the standby finisher
refactor(psci): don't use PSCI_INVALID_PWR_LVL to signal OFF state
docs(psci): drop outdated cache maintenance comment

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feat(mops): enable FEAT_MOPS in EL3 when INIT_UNUSED_NS_EL2=1

FEAT_MOPS, mandatory from Arm v8.8, is typically managed in EL2.
However, in configurations where NS_EL2 is not enabled,
EL3 must set th

feat(mops): enable FEAT_MOPS in EL3 when INIT_UNUSED_NS_EL2=1

FEAT_MOPS, mandatory from Arm v8.8, is typically managed in EL2.
However, in configurations where NS_EL2 is not enabled,
EL3 must set the HCRX_EL2.MSCEn bit to 1 to enable the feature.

This patch ensures FEAT_MOPS is enabled by setting HCRX_EL2.MSCEn to 1.

Change-Id: Ic4960e0cc14a44279156b79ded50de475b3b21c5
Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>

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perf(psci): pass my_core_pos around instead of calling it repeatedly

On some platforms plat_my_core_pos is a nontrivial function that takes a
bit of time and the compiler really doesn't like to inli

perf(psci): pass my_core_pos around instead of calling it repeatedly

On some platforms plat_my_core_pos is a nontrivial function that takes a
bit of time and the compiler really doesn't like to inline. In the PSCI
library, at least, we have no need to keep repeatedly calling it and we
can instead pass it around as an argument. This saves on a lot of
redundant calls, speeding the library up a bit.

Change-Id: I137f69bea80d7cac90d7a20ffe98e1ba8d77246f
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>

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refactor(psci): move timestamp collection to psci_pwrdown_cpu

psci_pwrdown_cpu has two callers, both of which save timestamps meant to
measure how much time the cache maintenance operations take. Mo

refactor(psci): move timestamp collection to psci_pwrdown_cpu

psci_pwrdown_cpu has two callers, both of which save timestamps meant to
measure how much time the cache maintenance operations take. Move the
timestamp collection inside to save on a bit of code duplication.

Change-Id: Ia2e7168faf7773d99b696cbdb6c98db7b58e31cf
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>

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refactor(psci): factor common code out of the standby finisher

psci_suspend_to_standby_finisher and psci_cpu_suspend_finish do mostly
the same stuff, besides the system management associated with th

refactor(psci): factor common code out of the standby finisher

psci_suspend_to_standby_finisher and psci_cpu_suspend_finish do mostly
the same stuff, besides the system management associated with their
respective wakeup paths. So bring the wake from standby path in line
with the wake from reset path - caller acquires locks and manages
context. This way both behave in vaguely the same way. We can also bring
their names in line so it's more apparent how they are different.

This is in preparation for cores waking from sleep, coming in another
patch. No functional change is expected.

Change-Id: I0e569d12f65d231606080faa0149d22efddc386d
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>

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refactor(psci): don't use PSCI_INVALID_PWR_LVL to signal OFF state

The target_pwrlvl field in the psci cpu data struct only stores the
highest power domain that a CPU_SUSPEND call affected, and is u

refactor(psci): don't use PSCI_INVALID_PWR_LVL to signal OFF state

The target_pwrlvl field in the psci cpu data struct only stores the
highest power domain that a CPU_SUSPEND call affected, and is used to
resume those same domains on warm reset. If the cpu is otherwise OFF
(never turned on or CPU_OFF), then this needs to be the highest power
level because we don't know the highest level that will be off.

So skip the invalidation and always keep the field to the maximum value.
During suspend the field will be lowered to the appropriate value and
then put back after wakeup.

Also, do that in the suspend to standby path as well as it will have
been written before the sleep and it might end up incorrect.

Change-Id: I614272ec387e1d83023c94700780a0f538a9a6b6
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>

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docs(psci): drop outdated cache maintenance comment

The comment was written when cache maintenance had to be considered when
calling this function. But that argument was dropped a while back and
thi

docs(psci): drop outdated cache maintenance comment

The comment was written when cache maintenance had to be considered when
calling this function. But that argument was dropped a while back and
this comment no longer makes any sense.

Change-Id: Ib68293f23cc3edca3010164dfe8866956b8e1a63
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>

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