MPMM is a core-specific microarchitectural feature. It has been present
in every Arm core since the Cortex-A510 and has been implemented in
exactly the same way. Despite that, it is enabled more like an
architectural feature with a top level enable flag. This utilised the
identical implementation.
This duality has left MPMM in an awkward place, where its enablement
should be generic, like an architectural feature, but since it is not,
it should also be core-specific if it ever changes. One choice to do
this has been through the device tree.
This has worked just fine so far, however, recent implementations expose
a weakness in that this is rather slow - the device tree has to be read,
there's a long call stack of functions with many branches, and system
registers are read. In the hot path of PSCI CPU powerdown, this has a
significant and measurable impact. Besides it being a rather large
amount of code that is difficult to understand.
Since MPMM is a microarchitectural feature, its correct placement is in
the reset function. The essence of the current enablement is to write
CPUPPMCR_EL3.MPMM_EN if CPUPPMCR_EL3.MPMMPINCTL == 0. Replacing the C
enablement with an assembly macro in each CPU's reset function achieves
the same effect with just a single close branch and a grand total of 6
instructions (versus the old 2 branches and 32 instructions).
Having done this, the device tree entry becomes redundant. Should a core
that doesn't support MPMM arise, this can cleanly be handled in the
reset function. As such, the whole ENABLE_MPMM_FCONF and platform hooks
mechanisms become obsolete and are removed.
Change-Id: I1d0475b21a1625bb3519f513ba109284f973ffdf
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Currently BRBE is being disabled for Realm world in EL3 by
switching the SBRBE bit in mdcr_el3 register to 0b00.
The patch removes the switching of SBRBE bits, and adds
context switch of BRBCR_EL2 register.
Change-Id: I66ca13edefc37e40fa265fd438b0b66f7d09b4bb
Signed-off-by: Sona Mathew <sonarebecca.mathew@arm.com>
* changes:
fix(cpus): clear CPUPWRCTLR_EL1.CORE_PWRDN_EN_BIT on reset
chore(docs): drop the "wfi" from `pwr_domain_pwr_down_wfi`
chore(psci): drop skip_wfi variable
feat(arm): convert arm platforms to expect a wakeup
fix(cpus): avoid SME related loss of context on powerdown
feat(psci): allow cores to wake up from powerdown
refactor: panic after calling psci_power_down_wfi()
refactor(cpus): undo errata mitigations
feat(cpus): add sysreg_bit_toggle
The following changes have been made:
* Add new sysreg definitions and ASM macro is_feat_sysreg128_present_asm
* Add registers TTBR0_EL2 and VTTBR_EL2 to EL3 crash handler output
* Use MRRS instead of MRS for registers TTBR0_EL1, TTBR0_EL2, TTBR1_EL1,
VTTBR_EL2 and PAR_EL1
Change-Id: I0e20b2c35251f3afba2df794c1f8bc0c46c197ff
Signed-off-by: Igor Podgainõi <igor.podgainoi@arm.com>
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
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>
SPE and TRBE don't have an outright EL3 disable, there are only
constraints on what's allowed. Since we only enable them for NS at the
moment, we want NS to own the buffers even when the feature should be
"disabled" for a world. This means that when we're running in NS
everything is as normal but when running in S/RL then tracing is
prohibited (since the buffers are owned by NS). This allows us to fiddle
with context a bit more without having to context switch registers.
Change-Id: Ie1dc7c00e4cf9bcc746f02ae43633acca32d3758
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
This patch enables support of FEAT_FPMR by enabling access
to FPMR register. It achieves it by setting the EnFPM bit of
SCR_EL3. This feature is currently enabled for NS world only.
Reference:
https://developer.arm.com/documentation/109697/2024_09/
Feature-descriptions/The-Armv9-5-architecture-extension?lang=en
Change-Id: I580c409b9b22f8ead0737502280fb9093a3d5dd2
Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Armv8.6 introduced the FEAT_LS64 extension, which provides a 64 *byte*
store instruction. A related instruction is ST64BV0, which will replace
the lowest 32 bits of the data with a value taken from the ACCDATA_EL1
system register (so that EL0 cannot alter them).
Using that ST64BV0 instruction and accessing the ACCDATA_EL1 system
register is guarded by two SCR_EL3 bits, which we should set to avoid a
trap into EL3, when lower ELs use one of those.
Add the required bits and pieces to make this feature usable:
- Add the ENABLE_FEAT_LS64_ACCDATA build option (defaulting to 0).
- Add the CPUID and SCR_EL3 bit definitions associated with FEAT_LS64.
- Add a feature check to check for the existing four variants of the
LS64 feature and detect future extensions.
- Add code to save and restore the ACCDATA_EL1 register on
secure/non-secure context switches.
- Enable the feature with runtime detection for FVP and Arm FPGA.
Please note that the *basic* FEAT_LS64 feature does not feature any trap
bits, it's only the addition of the ACCDATA_EL1 system register that
adds these traps and the SCR_EL3 bits.
Change-Id: Ie3e2ca2d9c4fbbd45c0cc6089accbb825579138a
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
This patch disables trapping to EL3 when the FEAT_D128
specific registers are accessed by setting the SCR_EL3.D128En bit.
If FEAT_D128 is implemented, then FEAT_SYSREG128 is implemented.
With FEAT_SYSREG128 certain system registers are treated as 128-bit,
so we should be context saving and restoring 128-bits instead of 64-bit
when FEAT_D128 is enabled.
FEAT_SYSREG128 adds support for MRRS and MSRR instruction which
helps us to read write to 128-bit system register.
Refer to Arm Architecture Manual for further details.
Change the FVP platform to default to handling this as a dynamic option
so the right decision can be made by the code at runtime.
Change-Id: I1a53db5eac29e56c8fbdcd4961ede3abfcb2411a
Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
It used to be the case that a FEAT_RME build could not be built with
FEAT_BRBE support. BRBE doesn't have a 3-world aware disable and
MDCR_EL3 was not context switched to allow for disabling in Realm world.
As of commit 123002f917 MDCR_EL3 is
context switched. Since the flag for BRBE support is
ENABLE_BRBE_FOR_NS, move brbe_enable() to only happen for NS world. The
other worlds will see BRBE disabled and branch recording prohibited.
This allows for a build with both RME and BRBE.
Note that EL2 BRBE registers are not context switched. Further work is
needed if non-NS support is required.
Change-Id: I82f0f08399dcd080902477dc9636bc4541685f89
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Arm v8.9 introduces FEAT_SCTLR2, adding SCTLR2_ELx registers.
Support this, context switching the registers and disabling
traps so lower ELs can access the new registers.
Change the FVP platform to default to handling this as a dynamic option
so the right decision can be made by the code at runtime.
Change-Id: I0c4cba86917b6b065a7e8dd6af7daf64ee18dcda
Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
Arm v8.9 introduces FEAT_THE, adding Translation Hardening Extension
Read-Check-Write mask registers, RCWMASK_EL1 and RCWSMASK_EL1.
Support this, context switching the registers and disabling
traps so lower ELs can access the new registers.
Change the FVP platform to default to handling this as a dynamic option
so the right decision can be made by the code at runtime.
Change-Id: I8775787f523639b39faf61d046ef482f73b2a562
Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
This patch moves EXTRACT_PARTNUM from errata abi includes
to arch.h which is part of common includes
Change-Id: Id8bbaf21566f3145a75cfa0dafec6823ed2df3a9
Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
This patch disables trapping to EL3 when the FEAT_FGT2
specific trap registers are accessed by setting the
SCR_EL3.FGTEn2 bit
Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: I6d2b614affb9067b2bc3d7bf0ae7d169d031592a
This patch enables FEAT_Debugv8p9 and prevents EL1/0 from
trapping to EL3 when accessing MDSELR_EL1 register by
setting the MDCR_EL3.EBWE bit.
Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: I3613af1dd8cb8c0d3c33dc959f170846c0b9695a
The ARMv8 ARM J.a describes the ID_AA64DFR0_EL1.PMUver field as allowing
a maximum version number of 8 now. The added features extend the Common
event number space and clarify on some UNPREDICTABLE behaviour.
None of this affects TF-A or any system registers, so just increase the
maximum known version number to let the FEATURE_DETECTION test pass on
ARMv8.8 implementations.
Change-Id: Icab48630c1635bcd78a710b443f0db01b8ff7c9b
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Adds driver support to preserve DSU PMU register values over a DSU
power cycle. This driver needs to be enabled by the platforms that
support DSU and also need it's PMU registers to be preserved
Change-Id: I7fc68a3d7d99ee369379aa5cd114fffc763fc0d2
Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Currently, the macros used to denote feature implementation
in hardware follow a random pattern with a few macros having
suffix as SUPPORTED and a few using the suffix IMPLEMENTED.
This patch aligns the macro names uniformly using the suffix
IMPLEMENTED across all the features and removes unused macros
pertaining to the Enable feat mechanism.
FEAT_SUPPORTED --> FEAT_IMPLEMENTED
FEAT_NOT_SUPPORTED --> FEAT_NOT_IMPLEMENTED
Change-Id: I61bb7d154b23f677b80756a4b6a81f74b10cd24f
Signed-off-by: Sona Mathew <sonarebecca.mathew@arm.com>
The following system registers are made part of save and restore
operations for EL1 context:
TRFCR_EL1
SCXTNUM_EL0
SCXTNUM_EL1
GCSCR_EL1
GCSCRE0_EL1
GCSPR_EL1
GCSPR_EL0
Change-Id: I1077112bdc29a6c9cd39b9707d6cf10b95fa15e3
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
The following system registers are made part of save and restore
operations for EL1 context:
MDCCINT_EL1
MDSCR_EL1
DISR_EL1
PIRE0_EL1
PIR_EL1
POR_EL1
S2POR_EL1
TCR2_EL1
Some of these registers are available as part of core Armv8-A
architecture while others are made available through various
architectural extensions.
Change-Id: I507dccb9053ba177e1b98100fceccd1f32bdfc5c
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
Cortex-A715 erratum 2344187 is a Cat B erratum that applies to r0p0,
r1p0 and is fixed in r1p1. The workaround is to set GCR_EL1.RRND to
0b1, and apply an implementation specific patch sequence.
SDEN: https://developer.arm.com/documentation/SDEN2148827/latest
Change-Id: I78ea39a91254765c964bff89f771af33b23f29c1
Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>
For a feature to be used at lower ELs, EL3 generally needs to disable
the trap so that lower ELs can access the system registers associated
with the feature. Lower ELs generally check ID registers to dynamically
detect if a feature is present (in HW) or not while EL3 Firmware relies
statically on feature build macros to enable a feature.
If a lower EL accesses a system register for a feature that EL3 FW is
unaware of, EL3 traps the access and panics. This happens mostly with
EL2 but sometimes VMs can also cause EL3 panic.
To provide platforms with capability to mitigate this problem, UNDEF
injection support has been introduced which injects a synchronous
exception into the lower EL which is supposed to handle the
synchronous exception.
The current support is only provided for aarch64.
The implementation does the following on encountering sys reg trap
- Get the target EL, which can be either EL2 or EL1
- Update ELR_ELx with ELR_EL3, so that after UNDEF handling in lower EL
control returns to original location.
- ESR_ELx with EC_UNKNOWN
- Update ELR_EL3 with vector address of sync exception handler with
following possible causes
- Current EL with SP0
- Current EL with SPx
- Lower EL using AArch64
- Re-create SPSR_EL3 which will be used to generate PSTATE at ERET
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: I1b7bf6c043ce7aec1ee4fc1121c389b490b7bfb7
Following utility functions/bit definitions done
- Write a helper function to return the presence of following features
- FEAT_UAO
- FEAT_EBEP
- FEAT_SEBEP
- FEAT_SSBS
- FEAT_NMI
- FEAT_PAN
- Add definition of some missing bits of SPSR.
- Add GCSCR_EL1 register encoding and accessor function.
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: Ifcead0dd8e3b32096e4ab810dde5d582a889785a
This feature provides support to context save the
SCXTNUM_ELx register. FEAT_CSV2_3 implies the implementation
of FEAT_CSV2_2. FEAT_CSV2_3 is supported in AArch64 state only
and is an optional feature in Arm v8.0 implementations.
This patch adds feature detection for v8.9 feature FEAT_CSV2_3,
adds macros for ID_AA64PFR0_EL1.CSV2 bits [59:56] for detecting
FEAT_CSV2_3 and macro for ENABLE_FEAT_CSV2_3.
Change-Id: Ida9f31e832b5f11bd89eebd6cc9f10ddad755c14
Signed-off-by: Sona Mathew <sonarebecca.mathew@arm.com>
This patch does following changes to restrict handling of lower EL
EA's only if FFH mode is enabled.
- Compile ea_delegate.S only if FFH mode is enabled.
- For Sync exception from lower ELs if the EC is not SMC or SYS reg
trap it was assumed that it is an EA, which is not correct. Move
the known Sync exceptions (EL3 Impdef) out of sync EA handler.
- Report unhandled exceptions if there are SError from lower EL in
KFH mode, as this is unexpected.
- Move code out of ea_delegate.S which are used for KFH mode.
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: I577089677d0ec8cde7c20952172bee955573d2ed
Restricts MPAM to only NS world and enables trap to EL3 for access of
MPAM registers from lower ELs of Secure and Realm world.
This patch removes MPAM enablement from global context and adds it to
EL3 State context which enables/disables MPAM during world switches.
Renamed ENABLE_MPAM_FOR_LOWER_ELS to ENABLE_FEAT_MPAM and
removed mpam_init_el3() as RESET behaviour is trapping.
Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: I131f9dba5df236a71959b2d425ee11af7f3c38c4
Bit1 in the CLUSTERPWRDN register is used to indicate on CLUSTERPACTIVE
that memory retention is required or not. It can be used for
L3 cache memory retention support.
Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Change-Id: I1c53c90ae3dfbed3be7e5b2b79f2c3565db81012
The original powerdown function for Gelas included SME disabling
instructions but did not check for the presence of SME before disabling.
This could lead to unexpected beaviors. This patch adds that check so
the feature is disabled only if it is present.
Change-Id: I582db53a6669317620e4f72a3eac87525897d3d0
Signed-off-by: Juan Pablo Conde <juanpablo.conde@arm.com>
At the moment we have some elaborate, but very schematic functions to
allow checking for CPU feature enablement. Adding some more becomes
tedious and is also error-prone.
Provide two wrapper macros that reduce most of the features to a
single line:
- CREATE_FEATURE_FUNCS(name, idreg, idfield, guard)
creates two functions read_<name>_id_field() and is_<name>_supported(),
that check the 4-bit CPU ID field starting at bit <idfield> in <idreg>
for being not 0, and compares it against the build time <guard> symbol.
For the usual feature (like PAN) this looks like:
CREATE_FEATURE_FUNCS(feat_pan, id_aa64mmfr1_el1,
ID_AA64MMFR1_EL1_PAN_SHIFT, ENABLE_FEAT_PAN)
- CREATE_FEATURE_FUNCS_VER(name, read_func, idvalue, guard)
creates one function to check for a certain CPU ID field *value*, so
when "!= 0" is not sufficient. It's meant to be used in addition to
the above macro, since that generates the CPU ID field accessor
function:
CREATE_FEATURE_FUNCS(feat_amu, id_aa64pfr0_el1, ID_AA64PFR0_AMU_SHIFT,
ENABLE_FEAT_AMU)
CREATE_FEATURE_FUNCS_VER(feat_amuv1p1, read_feat_amu_id_field,
ID_AA64PFR0_AMU_V1P1, ENABLE_FEAT_AMUv1p1)
Describe the existing feature accessor functions using those new macros,
to reduce the size of the file, improve readability and decrease the
possibility of (copy&paste) bugs.
Change-Id: Ib136a875b4857058ff561c4635ace344006f29bf
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
HFG*_EL2 registers control the fine-grained traps introduced by
FEAT_FGT. These traps come enabled by default so old systems unaware
of this feature can be trapped to EL3, not being able to handle the
trap correctly. This patch disables all fine-grained traps by default
to prevent such unexpected behavior.
Change-Id: If2ae97accbeed2bea51ae03b5225ce762ecffb25
Signed-off-by: Juan Pablo Conde <juanpablo.conde@arm.com>
These bits (MDCR_EL3.{NSTB, NSTBE, TTRF, TPM}, CPTR_EL3.TTA) only affect
EL2 (and lower) execution. Each feat_init_el3() is called long before
any lower EL has had a chance to execute, so setting the bits at reset
is redundant. Removing them from reset code also improves readability of
the immutable EL3 state.
Preserve the original intention for the TTA bit of "enabled for NS and
disabled everywhere else" (inferred from commit messages d4582d3088 and
2031d6166a and the comment). This is because CPTR_EL3 will be contexted
and so everyone will eventually get whatever NS has anyway.
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: I3d24b45d3ea80882c8e450b2d9db9d5531facec1
With the introduction of FEAT_RME MDCR_EL3 bits NSPB and NSPBE depend on
each other. The enable code relies on the register being initialised to
zero and omits to reset NSPBE. However, this is not obvious. Reset the
bit explicitly to document this.
Similarly, reset the STE bit , since it's part of the feature enablement.
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: I3714507bae10042cdccd2b7bc713b31d4cdeb02f
The FEAT_MTPMU feature disable runs very early after reset. This means,
it needs to be written in assembly, since the C runtime has not been
initialised yet.
However, there is no need for it to be initialised so soon. The PMU
state is only relevant after TF-A has relinquished control. The code
to do this is also very verbose and difficult to read. Delaying the
initialisation allows for it to happen with the rest of the PMU. Align
with FEAT_STATE in the process.
BREAKING CHANGE: This patch explicitly breaks the EL2 entry path. It is
currently unsupported.
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: I2aa659d026fbdb75152469f6d19812ece3488c6f
The enablement code for the PMU is scattered and difficult to track
down. Factor out the feature into its own lib/extensions folder and
consolidate the implementation. Treat it is as an architecturally
mandatory feature as it is currently.
Additionally, do some cleanup on AArch64. Setting overflow bits in
PMCR_EL0 is irrelevant for firmware so don't do it. Then delay the PMU
initialisation until the context management stage which simplifies the
early environment assembly. One side effect is that the PMU might count
before this happens so reset all counters to 0 to prevent any leakage.
Finally, add an enable to manage_extensions_realm() as realm world uses
the pmu. This introduces the HPMN fixup to realm world.
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: Ie13a8625820ecc5fbfa467dc6ca18025bf6a9cd3
Make the default value for MTPME always be 1 to preserve the reset
behaviour on newer revisions and on older revisions where the bit is
RES0 it doesn't matter.
Before its introduction MDCR_EL3.MTPME was RES0. Upon its introduction
the field resets to 1, making the MTPMU architecturally "enabled". As
such, the logical action on TF-A's part is to "disable" it, which led to
the introduction of DISABLE_MTPMU.
This hinges on the assumption that MDCR_EL3.MTPME will always be 1
unless the above flag is set. Unfortunately this is not the case, as the
reset value is overwritten at reset with a macro that sets this bit to
0.
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: Ie570774972f246b3aa41dc016ecbcc6fc2f581f6
At the moment, TF-A does not need to access VAs or PAs larger than
48 bits, so this patch just enables proper detection of support
for 4KB and 16KB granularity with 52 bits address support.
Signed-off-by: Javier Almansa Sobrino <javier.almansasobrino@arm.com>
Change-Id: Iccebbd5acc21f09dbb234ef21a802300e290ec18
At the moment we only support FEAT_RAS to be either unconditionally
compiled in, or to be not supported at all.
Add support for runtime detection (FEAT_RAS=2), by splitting
is_armv8_2_feat_ras_present() into an ID register reading function and
a second function to report the support status. That function considers
both build time settings and runtime information (if needed), and is
used before we access RAS related registers.
Also move the context saving code from assembly to C, and use the new
is_feat_ras_supported() function to guard its execution.
Change the FVP platform default to the now supported dynamic
option (=2), so the right decision can be made by the code at runtime.
Change-Id: I30498f72fd80b136850856244687400456a03d0e
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
FEAT_SME2 is an extension of FEAT_SME and an optional feature
from v9.2. Its an extension of SME, wherein it not only
processes matrix operations efficiently, but also provides
outer-product instructions to accelerate matrix operations.
It affords instructions for multi-vector operations.
Further, it adds an 512 bit architectural register ZT0.
This patch implements all the changes introduced with FEAT_SME2
to ensure that the instructions are allowed to access ZT0
register from Non-secure lower exception levels.
Additionally, it adds support to ensure FEAT_SME2 is aligned
with the existing FEATURE DETECTION mechanism, and documented.
Change-Id: Iee0f61943304a9cfc3db8f986047b1321d0a6463
Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
Arm v9.4 introduces support for Guarded Control Stack, providing
mitigations against some forms of RPO attacks and an efficient mechanism
for obtaining the current call stack without requiring a full stack
unwind. Enable access to this feature for EL2 and below, context
switching the newly added EL2 registers as appropriate.
Change the FVP platform to default to handling this as a dynamic option
so the right decision can be made by the code at runtime.
Signed-off-by: Mark Brown <broonie@kernel.org>
Change-Id: I691aa7c22e3547bb3abe98d96993baf18c5f0e7b
The value of register HCRX_EL2 is UNKNOWN out of reset. This can
affect the behavior in lower exception levels, such as traps to
EL2 due to a wrong configuration of the register upon reset.
This patch initializes the register at EL3 and disables all traps
related to it.
On the other hand, new fields have been introduced for HCRX_EL2,
which are now defined in this patch, so they can be used in
further development.
Signed-off-by: Juan Pablo Conde <juanpablo.conde@arm.com>
Change-Id: I0bf1e949aa0d3be9f227358ad088a1ecb96ce222
Arm v8.9 introduces a series of features providing a new way to set memory
permissions. Instead of directly encoding the permissions in the page
tables the PTEs contain indexes into an array of permissions stored in
system registers, allowing greater flexibility and density of encoding.
Enable access to these features for EL2 and below, context switching the
newly added EL2 registers as appropriate. Since all of FEAT_S[12]P[IO]E
are separately discoverable we have separate build time options for
enabling them, but note that there is overlap in the registers that they
implement and the enable bit required for lower EL access.
Change the FVP platform to default to handling them as dynamic options so
the right decision can be made by the code at runtime.
Signed-off-by: Mark Brown <broonie@kernel.org>
Change-Id: Icf89e444e39e1af768739668b505661df18fb234
When building the FVP platform with SPMD (which activates the context
switch code), but keeping ARM_ARCH_MINOR to 4 or lower, the assembler
will complain about the SCXTNUM_EL2 system register not being supported
by the "selected processor".
Allow building this combination of options by defining the SCXTNUM_EL2
register via the generic S3_ encoding, so any assembler, with any -march
settings, will generate the access without any warnings.
We do protect accesses to this register by runtime checks, if not
explicitly requested otherwise, so can override the toolchain in this
case.
Change-Id: I0941f4c4dcf541bd968c153b9c3fac61ca23f7ef
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
