If the systbl_chk.sh checks fail we print a message, but with no
indication that it's an error. That makes it hard to find in build
logs with eg. grep.
So prefix any output with "Error:".
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
it had always been pointless - compat_sys_select() sign-extends
the first argument just fine on its own.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[mpe: Use COMPAT_SPU_NEW() to keep systbl_chk.sh happy]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently the select system call is wired up with the SYSX_SPU()
macro. The SYSX_SPU() is not handled by systbl_chk.c, which means the
syscall number for select is not checked.
That hides the fact that the syscall number for select is actually
__NR__newselect not __NR_select.
In a following patch we'd like to drop ppc32_select() which means
select will become a regular COMPAT_SYS_SPU() syscall. But
COMPAT_SYS_SPU() can't deal with the fact that the syscall number is
actually __NR__newselect. We also can't just redefine __NR_select
because that's still used for the old select call.
So add a new COMPAT_NEW_SPU() that does the same thing as
COMPAT_SYS_SPU() except it encodes that we're using the new number.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[mpe: Fix sys_debug_setcontext() prototype to return long]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The "Power Architecture 64-Bit ELF V2 ABI" says in section 2.3.2.3:
[...] There are several rules that must be adhered to in order to ensure
reliable and consistent call chain backtracing:
* Before a function calls any other function, it shall establish its
own stack frame, whose size shall be a multiple of 16 bytes.
– In instances where a function’s prologue creates a stack frame, the
back-chain word of the stack frame shall be updated atomically with
the value of the stack pointer (r1) when a back chain is implemented.
(This must be supported as default by all ELF V2 ABI-compliant
environments.)
[...]
– The function shall save the link register that contains its return
address in the LR save doubleword of its caller’s stack frame before
calling another function.
To me this sounds like the equivalent of HAVE_RELIABLE_STACKTRACE.
This patch may be unneccessarily limited to ppc64le, but OTOH the only
user of this flag so far is livepatching, which is only implemented on
PPCs with 64-LE, a.k.a. ELF ABI v2.
Feel free to add other ppc variants, but so far only ppc64le got tested.
This change also implements save_stack_trace_tsk_reliable() for ppc64le
that checks for the above conditions, where possible.
Signed-off-by: Torsten Duwe <duwe@suse.de>
Signed-off-by: Nicolai Stange <nstange@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Provide timebase and timebase of last heartbeat in watchdog lockup
messages. Also provide a stack trace of when a CPU becomes un-stuck,
which can be useful -- it could be where irqs are re-enabled, so it
may be the end of the critical section which is responsible for the
latency which is useful information.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The watchdog heartbeat timestamp is updated when the local heartbeat
timer fires (or touch_nmi_watchdog() is called).
This is an interesting data point, so don't overwrite it when the
soft-NMI interrupt detects a hard lockup. That code came from a pre-
merge version to prevent hard lockup messages flood, but that's taken
care of with the stuck CPU logic now, so there is no reason to
update the heartbeat timestamp here.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This is not the case for the moment, but future releases of pHyp might
need to introduce some synchronisation routines under the hood which
would make the XIVE hcalls longer to complete.
As this was done for H_INT_RESET, let's wrap the other hcalls in a
loop catching the H_LONG_BUSY_* codes.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The hcall H_INT_RESET should be called to make sure XIVE is fully
reseted.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The hcall H_INT_RESET can take some time to complete and in such cases
it returns H_LONG_BUSY_* codes requiring the machine to sleep for a
while before retrying.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The kexec_state KEXEC_STATE_IRQS_OFF barrier is reached by all
secondary CPUs before the kexec_cpu_down() operation is called on
secondaries. This can raise conflicts and provoque errors in the XIVE
hcalls when XIVE is shutdown with H_INT_RESET on the primary CPU.
To synchronize the kexec_cpu_down() operations and make sure the
secondaries have completed their task before the primary starts doing
the same, let's move the primary kexec_cpu_down() after the
KEXEC_STATE_REAL_MODE barrier.
This change of the ending sequence of kexec is mostly useful on the
pseries platform but it impacts also the powernv, ps3 and 85xx
platforms. powernv can be easily tested and fixed but some caution is
required for the other two.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
For consideration:
* Add NVDIMM support - Enables greater testing, mambo device.
* Add IPv6 support built in + additional modules - Because it's 2018 maan.
* Add DEFERRED_STRUCT_PAGE_INIT - Let's see what breaks.
* Add PPC_MEMTRACE - Small powernv debugfs driver for getting hardware traces.
* Add MEMORY_FAILURE - Machine check exceptions can now drive memory failure.
* Turn on FANOTIFY - This is the current filesystem notification feature.
* Turn on SCOM_DEBUGFS - Handy for hardware/firmware debugging, security risk?
* Turn on async SCSI scanning - Let's see what breaks.
* Add MLX5 driver as a module - Popular demand.
* Add CRYPTO_CRCT10DIF_VPMSUM - POWER8 T10DIF acceleration.
* Make a bunch of USB hid drivers modules.
* Make SCSI SG, SR, and FC modules - FC is huge.
* Make video drivers except AST GPU modules - Also huge.
* Make PCI serial driver a module - Uncommon.
* Make more things modules, NFS FS, RAM disk, netconsole, MS-DOS fs.
* Get rid of /dev/port - Not used.
* Remove PPS and PTP subsystms - Unusual.
* Remove legacy BSD ttys - Long dead.
* Remove IDE - Deprecated and replaced with ATA.
* Remove WIRELESS - Until we get POWER9 laptops.
* Remove RAW - Long deprecated in favour of direct IO.
* Remove floppy, parport, and PS2 input devices - not supported.
* Remove virtio drivers, ballooning - We're host only.
* Remove PPP - Sorry Paulus.
This results in a significantly smaller vmlinux:
text data bss dec filename
13143383 5277944 1317856 19739183 vanilla
12263281 4852074 1341720 18457075 patched
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The B43 driver only needs CONFIG_SSB to support the WLAN card found in
the Wii. Configure it accordingly, and disable BCMA bus support to save
a bit of space.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This allows access to the SD card and the BCM4318 Wifi module.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Now that there's a GPIO driver for the Wii, let's enable the following
drivers:
- the GPIO driver itself
- gpio-keys
- gpio-poweroff
- gpio-leds and a few LED triggers
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The Wii doesn't have built-in Ethernet and USB Ethernet adapters are in
a different menu. Disable CONFIG_ETHERNET to save some space in support
code for Ethernet drivers.
Note that this patch doesn't disable any Ethernet drivers, because they
are not enabled by default.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The hcall_exit() tracepoint has retval defined as unsigned long. That
leads to humours results like:
bash-3686 [009] d..2 854.134094: hcall_entry: opcode=24
bash-3686 [009] d..2 854.134095: hcall_exit: opcode=24 retval=18446744073709551609
It's normal for some hcalls to return negative values, displaying them
as unsigned isn't very helpful. So change it to signed.
bash-3711 [001] d..2 471.691008: hcall_entry: opcode=24
bash-3711 [001] d..2 471.691008: hcall_exit: opcode=24 retval=-7
Which can be more easily compared to H_NOT_FOUND in hvcall.h
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
This commit was a stop-gap to prevent crashes on hotunplug, caused by
the mismatch between the 1G mappings used for the linear mapping and the
memory block size. Those issues are now resolved because we split the
linear mapping at hotunplug time if necessary, as implemented in commit
4dd5f8a99e ("powerpc/mm/radix: Split linear mapping on hot-unplug").
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Tested-by: Rashmica Gupta <rashmica.g@gmail.com>
Tested-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
By using IS_ENABLED() we can simplify __set_pte_at() by removing
redundant *ptep = pte.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When nohash and book3s header were split, some hash related stuff
remained in the nohash header. This patch removes them.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Duplicate pte_young() to avoid circular header dependency]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Unregister fadump on kexec down path otherwise the fadump registration
in new kexec-ed kernel complains that fadump is already registered.
This makes new kernel to continue using fadump registered by previous
kernel which may lead to invalid vmcore generation. Hence this patch
fixes this issue by un-registering fadump in fadump_cleanup() which is
called during kexec path so that new kernel can register fadump with
new valid values.
Fixes: b500afff11 ("fadump: Invalidate registration and release reserved memory for general use.")
Cc: stable@vger.kernel.org # v3.4+
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
FADump capture kernel boots in restricted memory environment preserving
the context of previous kernel to save vmcore. Supporting hugepages in
such environment makes things unnecessarily complicated, as hugepages
need memory set aside for them. This means most of the capture kernel's
memory is used in supporting hugepages. In most cases, this results in
out-of-memory issues while booting FADump capture kernel. But hugepages
are not of much use in capture kernel whose only job is to save vmcore.
So, disabling hugepages support, when fadump is active, is a reliable
solution for the out of memory issues. Introducing a flag variable to
disable HugeTLB support when fadump is active.
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The second kernel, during early boot after the crash, reserves rest of
the memory above boot memory size to make sure it does not touch any of the
dump memory area. It uses memblock_reserve() that reserves the specified
memory region irrespective of memory holes present within that region.
There are chances where previous kernel would have hot removed some of
its memory leaving memory holes behind. In such cases fadump kernel reports
incorrect number of reserved pages through arch_reserved_kernel_pages()
hook causing kernel to hang or panic.
Fix this by excluding memory holes while reserving rest of the memory
above boot memory size during second kernel boot after crash.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
I no longer have a functional version of this board for even the most
basic sanity boot testing, and they have not been available for purchase
for quite some years now.
There is no point in adding a burden to testing coverage that does
walk all the possible defconfigs, so with all the above in mind, it
makes sense to remove it. Of course it will remain in the git history
for anyone who happens to stumble on one and wants to tinker with it.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We've had dynamic ftrace support for over 9 years since Steve first
wrote it, all the distros use dynamic, and static is basically
untested these days, so drop support for static ftrace.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
With -mprofile-kernel, we always save the full register state in
ftrace_caller(). While this works, this is inefficient if we're not
interested in the register state, such as when we're using the function
tracer.
Rename the existing ftrace_caller() as ftrace_regs_caller() and provide
a simpler implementation for ftrace_caller() that is used when registers
are not required to be saved.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Our implementation matches that of the generic version, which also
handles FTRACE_UPDATE_MODIFY_CALL. So, remove our implementation in
favor of the generic version.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
For R_PPC64_REL24 relocations, we suppress emitting instructions for TOC
load/restore in the relocation stub if the relocation is for _mcount()
call when using -mprofile-kernel ABI.
To detect this, we check if the preceding instructions are per the
standard set of instructions emitted by gcc: either the two instruction
sequence of 'mflr r0; std r0,16(r1)', or the more optimized variant of a
single 'mflr r0'. This is not sufficient since nothing prevents users
from hand coding sequences involving a 'mflr r0' followed by a 'bl'.
For removing the toc save instruction from the stub, we additionally
check if the symbol is "_mcount". Add the same check here as well.
Also rename is_early_mcount_callsite() to is_mprofile_mcount_callsite()
since that is what is being checked. The use of "early" is misleading
since there is nothing involving this function that qualifies as early.
Fixes: 153086644f ("powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If function_graph tracer is enabled during kexec, we see the below
exception in the simulator:
root@(none):/# kexec -e
kvm: exiting hardware virtualization
kexec_core: Starting new kernel
[ 19.262020070,5] OPAL: Switch to big-endian OS
kexec: Starting switchover sequence.
Interrupt to 0xC000000000004380 from 0xC000000000004380
** Execution stopped: Continuous Interrupt, Instruction caused exception, **
Now that we have a more effective way to completely disable ftrace on
ppc64, let's also use that before switching to a new kernel during
kexec.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
During guest entry/exit, we switch over to/from the guest MMU context
and we cannot take exceptions in the hypervisor code.
Since ftrace may be enabled and since it can result in us taking a trap,
disable ftrace by setting paca->ftrace_enabled to zero. There are two
paths through which we enter/exit a guest:
1. If we are the vcore runner, then we enter the guest via
__kvmppc_vcore_entry() and we disable ftrace around this. This is always
the case for Power9, and for the primary thread on Power8.
2. If we are a secondary thread in Power8, then we would be in nap due
to SMT being disabled. We are woken up by an IPI to enter the guest. In
this scenario, we enter the guest through kvm_start_guest(). We disable
ftrace at this point. In this scenario, ftrace would only get re-enabled
on the secondary thread when SMT is re-enabled (via start_secondary()).
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Disable ftrace when a cpu is about to go offline. When the cpu is woken
up, ftrace will get enabled in start_secondary().
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On the boot cpu, though we enable paca->ftrace_enabled in early_setup()
(via cpu_ready_for_interrupts()), we don't start tracing until much
later since ftrace is not initialized yet and since we only support
DYNAMIC_FTRACE on powerpc. However, it is possible that ftrace has been
initialized by the time some of the secondary cpus start up. In this
case, we will try to trace some of the early boot code which can cause
problems.
To address this, move setting paca->ftrace_enabled from
cpu_ready_for_interrupts() to early_setup() for the boot cpu, and towards
the end of start_secondary() for secondary cpus.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add some helpers to enable/disable ftrace through paca->ftrace_enabled.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Re-arrange the last #ifdef section in preparation for a subsequent
change.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We have some C code that we call into from real mode where we cannot
take any exceptions. Though the C functions themselves are mostly safe,
if these functions are traced, there is a possibility that we may take
an exception. For instance, in certain conditions, the ftrace code uses
WARN(), which uses a 'trap' to do its job.
For such scenarios, introduce a new field in paca 'ftrace_enabled',
which is checked on ftrace entry before continuing. This field can then
be set to zero to disable/pause ftrace, and set to a non-zero value to
resume ftrace.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
smp_send_stop can lock up the IPI path for any subsequent calls,
because the receiving CPUs spin in their handler function. This
started becoming a problem with the addition of an smp_send_stop
call in the reboot path, because panics can reboot after doing
their own smp_send_stop.
The NMI IPI variant was fixed with ac61c11566 ("powerpc: Fix
smp_send_stop NMI IPI handling"), which leaves the smp_call_function
variant.
This is fixed by having smp_send_stop only ever do the
smp_call_function once. This is a bit less robust than the NMI IPI
fix, because any other call to smp_call_function after smp_send_stop
could deadlock, but that has always been the case, and it was not
been a problem before.
Fixes: f2748bdfe1 ("powerpc/powernv: Always stop secondaries before reboot/shutdown")
Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The NMI IPI handler for a receiving CPU increments nmi_ipi_busy_count
over the handler function call, which causes later smp_send_nmi_ipi()
callers to spin until the call is finished.
The stop_this_cpu() function never returns, so the busy count is never
decremeted, which can cause the system to hang in some cases. For
example panic() will call smp_send_stop() early on which calls
stop_this_cpu() on other CPUs, then later in the reboot path,
pnv_restart() will call smp_send_stop() again, which hangs.
Fix this by adding a special case to the stop_this_cpu() handler to
decrement the busy count, because it will never return.
Now that the NMI/non-NMI versions of stop_this_cpu() are different,
split them out into separate functions rather than doing #ifdef tricks
to share the body between the two functions.
Fixes: 6bed323762 ("powerpc: use NMI IPI for smp_send_stop")
Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Split out the functions, tweak change log a bit]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The OPAL RTC driver does not sleep in case it gets OPAL_BUSY or
OPAL_BUSY_EVENT from firmware, which causes large scheduling
latencies, up to 50 seconds have been observed here when RTC stops
responding (BMC reboot can do it).
Fix this by converting it to the standard form OPAL_BUSY loop that
sleeps.
Fixes: 628daa8d5a ("powerpc/powernv: Add RTC and NVRAM support plus RTAS fallbacks")
Cc: stable@vger.kernel.org # v3.2+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The current code extracts the physical address for UE errors and then
hooks it up into memory failure infrastructure. On successful
extraction of physical address it wrongly sets "handled = 1" which
means this UE error has been recovered. Since MCE handler gets return
value as handled = 1, it assumes that error has been recovered and
goes back to same NIP. This causes MCE interrupt again and again in a
loop leading to hard lockup.
Also, initialize phys_addr to ULONG_MAX so that we don't end up
queuing undesired page to hwpoison.
Without this patch we see:
Severe Machine check interrupt [Recovered]
NIP: [000000001002588c] PID: 7109 Comm: find
Initiator: CPU
Error type: UE [Load/Store]
Effective address: 00007fffd2755940
Physical address: 000020181a080000
...
Severe Machine check interrupt [Recovered]
NIP: [000000001002588c] PID: 7109 Comm: find
Initiator: CPU
Error type: UE [Load/Store]
Effective address: 00007fffd2755940
Physical address: 000020181a080000
Severe Machine check interrupt [Recovered]
NIP: [000000001002588c] PID: 7109 Comm: find
Initiator: CPU
Error type: UE [Load/Store]
Effective address: 00007fffd2755940
Physical address: 000020181a080000
Memory failure: 0x20181a08: recovery action for dirty LRU page: Recovered
Memory failure: 0x20181a08: already hardware poisoned
Memory failure: 0x20181a08: already hardware poisoned
Memory failure: 0x20181a08: already hardware poisoned
Memory failure: 0x20181a08: already hardware poisoned
Memory failure: 0x20181a08: already hardware poisoned
Memory failure: 0x20181a08: already hardware poisoned
...
Watchdog CPU:38 Hard LOCKUP
After this patch we see:
Severe Machine check interrupt [Not recovered]
NIP: [00007fffaae585f4] PID: 7168 Comm: find
Initiator: CPU
Error type: UE [Load/Store]
Effective address: 00007fffaafe28ac
Physical address: 00002017c0bd0000
find[7168]: unhandled signal 7 at 00007fffaae585f4 nip 00007fffaae585f4 lr 00007fffaae585e0 code 4
Memory failure: 0x2017c0bd: recovery action for dirty LRU page: Recovered
Fixes: 01eaac2b05 ("powerpc/mce: Hookup ierror (instruction) UE errors")
Fixes: ba41e1e1cc ("powerpc/mce: Hookup derror (load/store) UE errors")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The NPU has a limited number of address translation shootdown (ATSD)
registers and the GPU has limited bandwidth to process ATSDs. This can
result in contention of ATSD registers leading to soft lockups on some
threads, particularly when invalidating a large address range in
pnv_npu2_mn_invalidate_range().
At some threshold it becomes more efficient to flush the entire GPU
TLB for the given MM context (PID) than individually flushing each
address in the range. This patch will result in ranges greater than
2MB being converted from 32+ ATSDs into a single ATSD which will flush
the TLB for the given PID on each GPU.
Fixes: 1ab66d1fba ("powerpc/powernv: Introduce address translation services for Nvlink2")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Alistair Popple <alistair@popple.id.au>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Tested-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There is a single npu context per set of callback parameters. Callers
should be prevented from overwriting existing callback values so
instead return an error if different parameters are passed.
Fixes: 1ab66d1fba ("powerpc/powernv: Introduce address translation services for Nvlink2")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Alistair Popple <alistair@popple.id.au>
Reviewed-by: Mark Hairgrove <mhairgrove@nvidia.com>
Tested-by: Mark Hairgrove <mhairgrove@nvidia.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The pnv_npu2_init_context() and pnv_npu2_destroy_context() functions
are used to allocate/free contexts to allow address translation and
shootdown by the NPU on a particular GPU. Context initialisation is
implicitly safe as it is protected by the requirement mmap_sem be held
in write mode, however pnv_npu2_destroy_context() does not require
mmap_sem to be held and it is not safe to call with a concurrent
initialisation for a different GPU.
It was assumed the driver would ensure destruction was not called
concurrently with initialisation. However the driver may be simplified
by allowing concurrent initialisation and destruction for different
GPUs. As npu context creation/destruction is not a performance
critical path and the critical section is not large a single spinlock
is used for simplicity.
Fixes: 1ab66d1fba ("powerpc/powernv: Introduce address translation services for Nvlink2")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Alistair Popple <alistair@popple.id.au>
Reviewed-by: Mark Hairgrove <mhairgrove@nvidia.com>
Tested-by: Mark Hairgrove <mhairgrove@nvidia.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Don't do this via custom code, instead now that we have support in the
arch hotplug/hotunplug code, rely on those routines to do the right
thing.
The existing flush doesn't work because it uses ppc64_caches.l1d.size
instead of ppc64_caches.l1d.line_size.
Fixes: 9d5171a8f2 ("powerpc/powernv: Enable removal of memory for in memory tracing")
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch adds support for flushing potentially dirty cache lines
when memory is hot-plugged/hot-un-plugged. The support is currently
limited to 64 bit systems.
The bug was exposed when mappings for a device were actually
hot-unplugged and plugged in back later. A similar issue was observed
during the development of memtrace, but memtrace does it's own
flushing of region via a custom routine.
These patches do a flush both on hotplug/unplug to clear any stale
data in the cache w.r.t mappings, there is a small race window where a
clean cache line may be created again just prior to tearing down the
mapping.
The patches were tested by disabling the flush routines in memtrace
and doing I/O on the trace file. The system immediately
checkstops (quite reliablly if prior to the hot-unplug of the memtrace
region, we memset the regions we are about to hot unplug). After these
patches no custom flushing is needed in the memtrace code.
Fixes: 9d5171a8f2 ("powerpc/powernv: Enable removal of memory for in memory tracing")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Acked-by: Reza Arbab <arbab@linux.ibm.com>
Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
