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>
Errata printing is done directly via generic_errata_report.
This commit removes the unused \_cpu\()_errata_report
functions for all cores, and removes errata_func from cpu_ops.
Change-Id: I04fefbde5f0ff63b1f1cd17c864557a14070d68c
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
This involves replacing:
* the reset_func with the standard cpu_reset_func_{start,end} to apply
errata automatically
* the <cpu>_errata_report with the errata_report_shim to report errata
automatically
as well as specifically related to single errata for this CPU:
* the prologue with the workaround_<type>_start to do the checks and
framework registration automatically
* the epilogue with the workaround_<type>_end
* the checker function with the check_erratum_<type> to make it more
descriptive
Change-Id: I31cacbbdd4caa12b32e2c65ec456b0ab6b1a9101
Signed-off-by: Maksims Svecovs <maksims.svecovs@arm.com>
So far we have the ENABLE_AMU build option to include AMU register
handling code for enabling and context switch. There is also an
ENABLE_FEAT_AMUv1 option, solely to protect the HAFGRTR_EL2 system
register handling. The latter needs some alignment with the new feature
scheme, but it conceptually overlaps with the ENABLE_AMU option.
Since there is no real need for two separate options, unify both into a
new ENABLE_FEAT_AMU name in a first step. This is mostly just renaming at
this point, a subsequent patch will make use of the new feature handling
scheme.
Change-Id: I97d8a55bdee2ed1e1509fa9f2b09fd0bdd82736e
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Rainier CPU is based on Neoverse N1 R4P0 version which exhibits
the erratum 1868343. This patch inherits the workaround from
neoverse_n1.S file into rainier.S file for erratum 1868343.
Signed-off-by: Manoj Kumar <manoj.kumar3@arm.com>
Change-Id: I735595229716a77d26369943086de08384cafa70
This patch removes the Neoverse N1 CPU errata workaround for
bug 1542419 as the bug is not present in Rainier R0P0 core.
Change-Id: Icaca299b13ef830b2ee5129576aae655a6288e69
Signed-off-by: Manoj Kumar <manoj.kumar3@arm.com>
This patch adds CPU support for the Rainier CPU which is
derived from Neoverse N1 r4p0 CPU and implements the
Morello capability architecture.
Change-Id: Ic6b796481da5a66504ecb0648879446edf4c69fb
Signed-off-by: Manoj Kumar <manoj.kumar3@arm.com>
