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>
Cortex-A720 erratum 3699561 that applies to all revisions <= r0p2
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-2439421/latest/
Change-Id: I7ea3aaf3e7bf6b4f3648f6872e505a41247b14ba
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
Cortex-A720 erratum 2792132 is a Cat B erratum that is present
in revision r0p0, r0p1 and is fixed in r0p2.
The workaround is to set bit[26] of the CPUACTLR2_EL1 to 1.
SDEN documentation:
https://developer.arm.com/documentation/SDEN2439421/latest
Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: I8d11fe65a2ab5f79244cc3395d0645f77256304c
Cortex-A720 erratum 2844092 is a Cat B erratum that is present
in revisions r0p0, r0p1 and is fixed in r0p2.
The workaround is to set bit[11] of CPUACTLR4_EL1 register.
SDEN documentation:
https://developer.arm.com/documentation/SDEN-2439421/latest
Change-Id: I3d8eacb26cba42774f1f31c3aae2a0e6fecec614
Signed-off-by: Sona Mathew <sonarebecca.mathew@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>
Cortex-A720 erratum 2926083 is a Cat B erratum that is present
in revisions r0p0, r0p1 and is fixed in r0p2. The errata is only
present when SPE (Statistical Profiling Extension) is implemented
and enabled.
The workaround is to set bits[58:57] of the CPUACTLR_EL1 to 'b11
when SPE is "implemented and enabled".
SDEN documentation:
https://developer.arm.com/documentation/SDEN2439421/latest
Change-Id: I30182c3893416af65b55fca9a913cb4512430434
Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
Cortex-A720 erratum 2940794 is a Cat B erratum that is present
in revision r0p0, r0p1 and is fixed in r0p2.
The workaround is to set bit[37] of the CPUACTLR2_EL1 to 1.
SDEN documentation:
https://developer.arm.com/documentation/SDEN2439421/latest
Change-Id: I1488802e0ec7c16349c9633bb45de4d0e1faa9ad
Signed-off-by: Bipin Ravi <biprav01@u203721.austin.arm.com>
Adapt to use errata frame-work cpu macro helpers for following cpus:
- cortex-a520
- cortex-a720
- cortex-x4
- cortex-chaberton
- cortex-blackhawk
- Use sysreg_bit_set helper macro for enabling of any system register
bit field.
- Use errata_report_shim macro for reporting errata.
- Use cpu_reset_func_start/end helpers for adding cpu reset functions.
Testing:
- Manual comparison of disassembly with and without conversion.
- Using the test script in gerrit - 19136
- Building with erratas and stepping through from ArmDS and running tftf.
Change-Id: I954fb603aa3746e02f2288656b98148d9cfd7843
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
