Certain erratum workarounds like Neoverse N1 1542419, need a part
of their mitigation done in EL3 and the rest in lower EL. But currently
such workarounds return HIGHER_EL_MITIGATION which indicates that the
erratum has already been mitigated by a higher EL(EL3 in this case)
which causes the lower EL to not apply it's part of the mitigation.
This patch fixes this issue by adding support for split workarounds
so that on certain errata we return AFFECTED even though EL3 has
applied it's workaround. This is done by reusing the chosen field of
erratum_entry structure into a bitfield that has two bitfields -
Bit 0 indicates that the erratum has been enabled in build,
Bit 1 indicates that the erratum is a split workaround and should
return AFFECTED instead of HIGHER_EL_MITIGATION.
SDEN documentation:
https://developer.arm.com/documentation/SDEN885747/latest
Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: Iec94d665b5f55609507a219a7d1771eb75e7f4a7
Errata application is painful for performance. For a start, it's done
when the core has just come out of reset, which means branch predictors
and caches will be empty so a branch to a workaround function must be
fetched from memory and that round trip is very slow. Then it also runs
with the I-cache off, which means that the loop to iterate over the
workarounds must also be fetched from memory on each iteration.
We can remove both branches. First, we can simply apply every erratum
directly instead of defining a workaround function and jumping to it.
Currently, no errata that need to be applied at both reset and runtime,
with the same workaround function, exist. If the need arose in future,
this should be achievable with a reset + runtime wrapper combo.
Then, we can construct a function that applies each erratum linearly
instead of looping over the list. If this function is part of the reset
function, then the only "far" branches at reset will be for the checker
functions. Importantly, this mitigates the slowdown even when an erratum
is disabled.
The result is ~50% speedup on N1SDP and ~20% on AArch64 Juno on wakeup
from PSCI calls that end in powerdown. This is roughly back to the
baseline of v2.9, before the errata framework regressed on performance
(or a little better). It is important to note that there are other
slowdowns since then that remain unknown.
Change-Id: Ie4d5288a331b11fd648e5c4a0b652b74160b07b9
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
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>
- errata.h is using incorrect header macro ERRATA_REPORT_H fix this.
- Group errata function utilities.
Change-Id: I6a4a8ec6546adb41e24d8885cb445fa8be830148
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
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
Apply the mitigation only for the revision and variant
mentioned in the SDEN.
SDEN Documentation:
https://developer.arm.com/documentation/SDEN859515/latest
Change-Id: Ifda1f4cb32bdec9a9af29397ddc03bf22a7a87fc
Signed-off-by: Sona Mathew <sonarebecca.mathew@arm.com>
This patch implements errata functions for two errata, both of them
disable TRBE as a workaround. This patch doesn't have functions
that disable TRBE but only implemented helper functions that are
used to detect cores affected by Errata 2938996(Cortex-A520) & 2726228(Cortex-X4)
Cortex-X4 SDEN documentation:
https://developer.arm.com/documentation/SDEN2432808/latest
Cortex-A520 SDEN Documentation:
https://developer.arm.com/documentation/SDEN-2444153/latest
Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: I8f886a1c21698f546a0996c719cc27dc0a23633a
In all non-trivial cases the CPU specific errata functions
already call generic_errata_report, this cuts out the middleman
by directly calling generic_errata_report from
print_errata_status.
The CPU specific errata functions (cpu_ops->errata_func)
can now be removed from all cores, and this field can be
removed from cpu_ops.
Also removes the now unused old errata reporting
function and macros.
Change-Id: Ie4a4fd60429aca37cf434e79c0ce2992a5ff5d68
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
For runtime errata, we should avoid generating calls to
`cpu_get_rev_var` unless its necessary. Make the path that generates
this call parameterized, and cache the result in a temporary register to
allow future calls that go down the alternate path to retrieve the cache
CPU revision.
Change-Id: I9882ede76568fbd9a7ccd4caa74eff0c66a7b20e
Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>
Figuring out the naming format of errata is annoying, so add a shorthand
for the custom checker functions. Also add some more semantic macros
instead of passing around constants.
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: Ibdcf72146738026df4ebd047bfb30790fd4a1053
Using the errata framework per-cpu data structure, errata can all be
reported automatically through a single standard errata reporter which
can replace the cpu-specific ones.
This reporter can also enforce the ordering requirement of errata.
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: I7d2d5ac5bcb9d21aed0d560d7d23919a323ffdab
Errata implementation involves adding a lot of boilerplate to random
places with just conventions on how to do them. Copy pasting is the
usual method for doing this. The result is an error-prone and verbose
patch that is a nightmare to get through review.
Errata workarounds have a very large degree of similarity - most of them
involve setting a bit at reset. As such most of the boilerplate is not
strictly necessary. To solve this, add a collection of assembly macros
to wrap errata implementations such that only the actual mitigations
need to be written. A new erratum mitigation looks something like:
workaround_reset_start cortex_a77, ERRATUM(1925769), ERRATA_A77_1925769
sysreg_bit_set CORTEX_A77_CPUECTLR_EL1, CORTEX_A77_CPUECTLR_EL1_BIT_8
workaround_reset_end cortex_a77, ERRATUM(1925769)
check_erratum_ls cortex_a77, ERRATUM(1925769), CPU_REV(1, 1)
Note, that the long comment on every mitigation is missing. This is on
purpose, as this new format includes all of its contents into an easily
readable format.
The workaround wrappers add an erratum entry (24 bytes) to a per-cpu
data structure which can then be read by a standard reset function to
apply all errata automatically. This has the added benefit of collecting
all errata TF-A knows about in a central way, which was previously
missing. This can then be used at runtime with the errata ABI.
If an erratum doesn't fit this standard definition (eg. the
CVE_2022_23960), it can progressively be unwrapped to the old
convention. The only differences are that the naming format is slightly
more verbose and a call to add_erratum_entry is needed to inform the
framework about the errata.
Finally, the internal workaround names change a tiny bit, especially
CVEs.
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: Iac644f85dcf85b8279b25e83baf1e7d08b253b16
The function is called in a fully initialised C environment and calls
into other C functions. The Aarch differences are minimal and are hidden
by the pre-existing headers. Converting it results into cleaner code
that is the same across both Aarch64 and Aarch32.
To avoid having to do very ugly pointer arithmetic, define a C struct
for the cpu_ops for both Aarch64 and Aarch32.
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: Idc07c4064e03143c88a4a0e2d10ceda70ba19a50
The ERRATA_XXX macros, used in cpu_helpers.S, are necessary for the
check_errata_xxx family of functions. The CPU_REV should be used in the
cpu files but for whatever reason the values have been hard-coded so far
(at the cost of readability). It's evident this file is not strictly for
status reporting.
The new purpose of this file is to make it a one-stop-shop for all
things errata.
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: I1ce22dd36df5aa0bcfc5f2772251f91af8703dfb
2023-05-30 09:31:15 +01:00
Renamed from include/lib/cpus/errata_report.h (Browse further)
