If cpu_relax() is called when not at medium SMT priority, it will lose
the prior priority and return at medium. Add a debug check to catch
this, which would have flagged the previous bug.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
This provides an initial facility to decode machine checks into
human readable strings, plus a minimum amount of metadata that
a handler has to understand in order to deal with the machine
check.
For now this is only used by skiboot to make MCE reporting nicer,
and an ERAT flush recovery attempt which is more about code
coverage than really being helpful.
***********************************************
Fatal MCE at 00000000300c9c0c .memcmp+0x3c MSR 9000000000141002
Cause: instruction fetch TLB multi-hit error
Effective address: 0x00000000300c9c0c
...
The intention is to subsequently provide an OPAL API with this
information that will enable an OS to implement a machine
independent OPAL machine check driver.
The code and data tables are derived from Linux code that I wrote,
so relicensing is okay.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
This patch disables Protected Execution Faciltiy (PEF).
This software procedure is needed for the lab because Cronus will be
configured to bring the machine up with PEF on. Hostboot has a similar
procedure for running with PEF off.
Skiboot can run with PEF on but the kernel cannot; the kernel will take
a machine check when trying to write a protected resource, such as the
PTCR.
So, use this until we have an ultravisor, or if we want to use BML with
Cronus without UV = 1.
Signed-off-by: Ryan Grimm <grimm@linux.ibm.com>
Tested-by: Alistair Popple <alistair@popple.id.au>
[oliver: replaced bare urfid with a macro for toolchain compatibility]
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Fused code mode is currently not supported in OPAL. Continuing to
boot the system would result in errors at later stages of boot.
Wait for console to be up and print message for developers to check
and fix the system modes.
Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
SPDX makes it a simpler diff.
I have audited the commit history of each file to ensure that they are
exclusively authored by IBM and thus we have the right to relicense.
The motivation behind this is twofold:
1) We want to enable experiments with coreboot, which is GPLv2 licensed
2) An upcoming firmware component wants to incorporate code from skiboot
and code from the Linux kernel, which is GPLv2 licensed.
I have gone through the IBM internal way of gaining approval for this.
The following files are not exclusively authored by IBM, so are *not*
included in this update (I will be seeking approval from contributors):
core/direct-controls.c
core/flash.c
core/pcie-slot.c
external/common/arch_flash_unknown.c
external/common/rules.mk
external/gard/Makefile
external/gard/rules.mk
external/opal-prd/Makefile
external/pflash/Makefile
external/xscom-utils/Makefile
hdata/vpd.c
hw/dts.c
hw/ipmi/ipmi-watchdog.c
hw/phb4.c
include/cpu.h
include/phb4.h
include/platform.h
libflash/libffs.c
libstb/mbedtls/sha512.c
libstb/mbedtls/sha512.h
platforms/astbmc/barreleye.c
platforms/astbmc/garrison.c
platforms/astbmc/mihawk.c
platforms/astbmc/nicole.c
platforms/astbmc/p8dnu.c
platforms/astbmc/p8dtu.c
platforms/astbmc/p9dsu.c
platforms/astbmc/vesnin.c
platforms/rhesus/ec/config.h
platforms/rhesus/ec/gpio.h
platforms/rhesus/gpio.c
platforms/rhesus/rhesus.c
platforms/astbmc/talos.c
platforms/astbmc/romulus.c
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>
[oliver: fixed up the drift]
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Using traps for assertions like Linux does gives a few advantages:
- The asm code leading to the failure condition is nicer.
- The interrupt gives a clean snapshot of machine state to dump.
The difficulty with using traps for this in OPAL is that the runtime
component will not deal well with the OS taking the 0x700 interrupt
caused by a trap in OPAL.
The long term goal is to improve the ability of the OS to inspect and
debug OPAL at runtime. For now though, the traps are patched out before
passing control to the OS, and the assert falls through to in-line
failure handling.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[oliver: commit prefix, added and renamed the FWTS label, fix tests]
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Use Software Package Data Exchange (SPDX) to indicate license for each
file that is unique to skiboot.
At the same time, ensure the (C) who and years are correct.
See https://spdx.org/
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>
[oliver: Added a few missing files]
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
It's been a good long while since either OPAL POWER7 user touched a
machine, and even longer since they'd have been okay using an old
version rather than tracking master.
There's also been no testing of OPAL on POWER7 systems for an awfully
long time, so it's pretty safe to assume that it's very much bitrotted.
It also saves a whole 14kb of xz compressed payload space.
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>
Enthusiasticly-Acked-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>
The ISA specifies that MCE interrupts in power saving modes will enter
at 0x200 with powersave bits in SRR1 set. This is not currently
supported properly, the MCE will just happen like a normal interrupt,
but GPRs could be lost, which would lead to crashes (e.g., r1, r2, r13
etc).
So check the power save bits similarly to the sreset vector, and
handle this properly.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>
Detect non-powersave sresets and send them to the normal exception
handler which prints registers and stack.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>
Currently if Linux boots with a non-zero PCR, things can go bad where
some early userspace programs can take illegal instructions. This is
being fixed in Linux, but in the mean time, we should cleanup in
skiboot also.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>
Clang doesn't know about msgsnd, msgclr, msgsync yet. Open code them
using .long asm() calls.
Instead of introducing ifdef hell, do this unconditionally for all
compilers as the code generation does not change.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>
In P9, we have to enable "flush the instruction cache" bit along with
"attn instruction support" bit to trigger attention.
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
cmpxchg will be used in a subsequent change, and this reduces the
amount of asm code.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[stewart: fix some ifdef __TEST__ foo to ensure unittests work]
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
POWER7/8 use DSCR=0. POWER9 preferred value has "stride-N" enabled.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Add pm idle support to POWER9. IPIs are implemented with doorbells.
POWER9 can use the EC=ESL=0 (lite) stop when sreset is not available.
EC=ESL=1 state with RL=3 is enabled when we have a sreset wakeup.
Deep idle states are not implemented.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
This implements OPAL_SIGNAL_SYSTEM_RESET, using scom registers to
quiesce the target thread and raise a system reset exception on it.
It has been tested on DD2 with stop0 ESL=0 and ESL=1 shallow power
saving modes.
DD1 is not implemented because it is sufficiently different as to
make support difficult.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[stewart@linux.vnet.ibm.com: fixup hdat_to_dt test]
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
There's a bug in current Linux kernels leaving crap in those registers
accross kexec and not sanitizing them on boot. This breaks kexec under
some circumstances (such as booting a hash kernel from a radix one
on P9 DD2.0).
The long term fix is in Linux, but this workaround is a reasonable
way of "sanitizing" those SPRs when Linux calls opal_reinit_cpus()
and shouldn't have adverse effects.
We could also use that same mechanism to cleanup other things as
well such as restoring some other SPRs to their default value in
the future.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
This adds new opal_reinit_cpus() flags to setup radix or hash
mode in HID[8] on POWER9.
By default HID[8] will be set. On P9 DD1.0, Linux will change
it as needed. On P9 DD2.0 hash works in radix mode (radix is
really "dual" mode) so KVM won't break and existing kernels
will work.
Newer kernels built for hash will call this to clear the HID bit
and thus get the full size of the TLB as an optimization.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Recent CPUs have introduced a lower SMT priority. This uses the
Linux pattern of executing priority nops in descending order to
get a simple portable way to put the CPU into lowest SMT priority.
Introduce smt_lowest() and use it in place of smt_very_low and
smt_low ; smt_very_low sequences.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
This is an experimental patch that implements "Fast reboot" on P8
machines.
The basic idea is that when the OS calls OPAL reboot, we gather all
the threads in the system using a combination of patching the reset
vector and soft-resetting them, then cleanup a few bits of hardware
(we do re-probe PCIe for example), and reload & restart the bootloader.
For Trusted Boot, this means we *add* measurements to the TPM, so you
will get *different* PCR values as compared to a full IPL. This makes
sense as if you want to be sure you are running something known then,
well, do a full IPL as soft reset should never be trusted to clear any
malicious code.
This is very experimental and needs a lot of testing and also auditing
code for other bits of HW that might need to be cleaned up.
BenH TODO: I also need to check if we are properly PERST'ing PCI devices.
This is partially based on old code I had to do that on P7. I only
support it on P8 though as there are issues with the PSI interrupts
on P7 that cannot be reliably solved.
Even though this should be considered somewhat experimental, we've had
a lot of success on a variety of machines. Dozens/hundreds of reboots
across Tuleta, Garrison and Habanero.
Currently, we've hidden it behind a NVRAM config option, which *is*
liable to change in the future (to ensure that only those who know
what they're doing enable it)
You can enable the experimental support via nvram option:
nvram -p ibm,skiboot --update-config experimental-fast-reset=feeling-lucky
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[stewart@linux.vnet.ibm.com: hide behind nvram option, include Mambo fixes
from Mikey]
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Nicholas Piggin
Vaidyanathan Srinivasan
Ryan Grimm
Joel Stanley
Stewart Smith
Reza Arbab
Michael Neuling
Vasant Hegde
Benjamin Herrenschmidt